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freebsd-skq/sys/kern/vfs_lookup.c

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/* -> /*- for copyright notices, minor format tweaks as necessary
2005-01-06 23:35:40 +00:00
/*-
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
Renumber license clauses in sys/kern to avoid skipping #3
2016-09-15 13:16:20 +00:00
* 3. Neither the name of the University nor the names of its contributors
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_lookup.c 8.4 (Berkeley) 2/16/94
*/
Use __FBSDID().
2003-06-11 00:56:59 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
Second-to-last commit implementing Capsicum capabilities in the FreeBSD kernel for FreeBSD 9.0: Add a new capability mask argument to fget(9) and friends, allowing system call code to declare what capabilities are required when an integer file descriptor is converted into an in-kernel struct file *. With options CAPABILITIES compiled into the kernel, this enforces capability protection; without, this change is effectively a no-op. Some cases require special handling, such as mmap(2), which must preserve information about the maximum rights at the time of mapping in the memory map so that they can later be enforced in mprotect(2) -- this is done by narrowing the rights in the existing max_protection field used for similar purposes with file permissions. In namei(9), we assert that the code is not reached from within capability mode, as we're not yet ready to enforce namespace capabilities there. This will follow in a later commit. Update two capability names: CAP_EVENT and CAP_KEVENT become CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they represent. Approved by: re (bz) Submitted by: jonathan Sponsored by: Google Inc
2011-08-11 12:30:23 +00:00
#include "opt_capsicum.h"
Converted two options over to the new scheme: USER_LDT and KTRACE.
1996-01-03 21:42:35 +00:00
#include "opt_ktrace.h"
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/param.h>
Fix up some sloppy coding practices: - Delete redundant declarations. - Add -Wredundant-declarations to Makefile.i386 so they don't come back. - Delete sloppy COMMON-style declarations of uninitialized data in header files. - Add a few prototypes. - Clean up warnings resulting from the above. NB: ioconf.c will still generate a redundant-declaration warning, which is unavoidable unless somebody volunteers to make `config' smarter.
1994-08-18 22:36:09 +00:00
#include <sys/systm.h>
Untangle vfsinit() a bit. Use seperate sysinit functions rather than having a super-function calling bits all over the place.
2000-12-06 07:09:08 +00:00
#include <sys/kernel.h>
Update kernel inclusions of capability.h to use capsicum.h instead; some further refinement is required as some device drivers intended to be portable over FreeBSD versions rely on __FreeBSD_version to decide whether to include capability.h. MFC after: 3 weeks
2014-03-16 10:55:57 +00:00
#include <sys/capsicum.h>
Add the support for the AT_FDCWD and fd-relative name lookups to the namei(9). Based on the submission by rdivacky, sponsored by Google Summer of Code 2007 Reviewed by: rwatson, rdivacky Tested by: pho
2008-03-31 12:01:21 +00:00
#include <sys/fcntl.h>
Add hierarchical jails. A jail may further virtualize its environment by creating a child jail, which is visible to that jail and to any parent jails. Child jails may be restricted more than their parents, but never less. Jail names reflect this hierarchy, being MIB-style dot-separated strings. Every thread now points to a jail, the default being prison0, which contains information about the physical system. Prison0's root directory is the same as rootvnode; its hostname is the same as the global hostname, and its securelevel replaces the global securelevel. Note that the variable "securelevel" has actually gone away, which should not cause any problems for code that properly uses securelevel_gt() and securelevel_ge(). Some jail-related permissions that were kept in global variables and set via sysctls are now per-jail settings. The sysctls still exist for backward compatibility, used only by the now-deprecated jail(2) system call. Approved by: bz (mentor)
2009-05-27 14:11:23 +00:00
#include <sys/jail.h>
Undo part of the tangle of having sys/lock.h and sys/mutex.h included in other "system" header files. Also help the deprecation of lockmgr.h by making it a sub-include of sys/lock.h and removing sys/lockmgr.h form kernel .c files. Sort sys/*.h includes where possible in affected files. OK'ed by: bde (with reservations)
2001-05-01 08:13:21 +00:00
#include <sys/lock.h>
Include sys/_lock.h and sys/_mutex.h to reduce namespace pollution. Requested by: jhb
2002-01-13 21:37:49 +00:00
#include <sys/mutex.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/filedesc.h>
#include <sys/proc.h>
Add SDT DTrace probes for namei(): vfs:namei:lookup:entry takes parent directory vnode pointer, path to look up, and lookup flags. vfs:namei:lookup:return takes an error value, and if successful, the returned vnode pointer. MFC after: 1 month
2009-04-06 10:32:40 +00:00
#include <sys/sdt.h>
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
#include <sys/syscallsubr.h>
- Include opt_vfs.h for LOOKUP_SHARED. - Control the behavior of shared lookups with the lookup_shared sysctl which has its default behavior set via the LOOKUP_SHARED option.
2005-04-03 23:50:20 +00:00
#include <sys/sysctl.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
Add AUDITVNODE[12] flags to namei(), which cause namei() to audit path and vnode attribute information for looked up vnodes during the lookup operation. This will allow consumers of namei() to specify that this information be added to the in-process audit record. Submitted by: wsalamon Obtained from: TrustedBSD Project
2006-02-05 15:42:01 +00:00
#include <security/audit/audit.h>
Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now contains the userspace and user<->kernel API and definitions, with all in-kernel interfaces moved to mac_framework.h, which is now included across most of the kernel instead. This change is the first step in a larger cleanup and sweep of MAC Framework interfaces in the kernel, and will not be MFC'd. Obtained from: TrustedBSD Project Sponsored by: SPARTA
2006-10-22 11:52:19 +00:00
#include <security/mac/mac_framework.h>
Add AUDITVNODE[12] flags to namei(), which cause namei() to audit path and vnode attribute information for looked up vnodes during the lookup operation. This will allow consumers of namei() to specify that this information be added to the in-process audit record. Submitted by: wsalamon Obtained from: TrustedBSD Project
2006-02-05 15:42:01 +00:00
Remove references to vm_zone.h and switch over to the new uma API. Also, remove maxsockets. If you look carefully you'll notice that the old zone allocator never honored this anyway.
2002-03-20 04:09:59 +00:00
#include <vm/uma.h>
Unspammed nested include of <vm/vm_zone.h>.
1997-12-27 02:56:39 +00:00
- Solve a problem where a vput could be called on an outgoing directory without Giant held. Do this by tracking the vfslocked state for the directory seperate from the child. This is only important in the case where we cross a mountpoint. Sponsored by: Isilon Systems, Inc. MFC After: 3 days
2006-02-01 09:34:32 +00:00
#define NAMEI_DIAGNOSTIC 1
Make NAMEI_DIAGNOSTIC compile again and add a stragic vprint()
2004-12-03 12:15:39 +00:00
#undef NAMEI_DIAGNOSTIC
Add SDT DTrace probes for namei(): vfs:namei:lookup:entry takes parent directory vnode pointer, path to look up, and lookup flags. vfs:namei:lookup:return takes an error value, and if successful, the returned vnode pointer. MFC after: 1 month
2009-04-06 10:32:40 +00:00
SDT_PROVIDER_DECLARE(vfs);
dtrace sdt: remove the ugly sname parameter of SDT_PROBE_DEFINE In its stead use the Solaris / illumos approach of emulating '-' (dash) in probe names with '__' (two consecutive underscores). Reviewed by: markj MFC after: 3 weeks
2013-11-26 08:46:27 +00:00
SDT_PROBE_DEFINE3(vfs, namei, lookup, entry, "struct vnode *", "char *",
Add SDT DTrace probes for namei(): vfs:namei:lookup:entry takes parent directory vnode pointer, path to look up, and lookup flags. vfs:namei:lookup:return takes an error value, and if successful, the returned vnode pointer. MFC after: 1 month
2009-04-06 10:32:40 +00:00
"unsigned long");
dtrace sdt: remove the ugly sname parameter of SDT_PROBE_DEFINE In its stead use the Solaris / illumos approach of emulating '-' (dash) in probe names with '__' (two consecutive underscores). Reviewed by: markj MFC after: 3 weeks
2013-11-26 08:46:27 +00:00
SDT_PROBE_DEFINE2(vfs, namei, lookup, return, "int", "struct vnode *");
Add SDT DTrace probes for namei(): vfs:namei:lookup:entry takes parent directory vnode pointer, path to look up, and lookup flags. vfs:namei:lookup:return takes an error value, and if successful, the returned vnode pointer. MFC after: 1 month
2009-04-06 10:32:40 +00:00
Untangle vfsinit() a bit. Use seperate sysinit functions rather than having a super-function calling bits all over the place.
2000-12-06 07:09:08 +00:00
/*
* Allocation zone for namei
*/
Remove references to vm_zone.h and switch over to the new uma API. Also, remove maxsockets. If you look carefully you'll notice that the old zone allocator never honored this anyway.
2002-03-20 04:09:59 +00:00
uma_zone_t namei_zone;
Below is slightly edited description of the LOR by Tor Egge: -------------------------- [Deadlock] is caused by a lock order reversal in vfs_lookup(), where [some] process is trying to lock a directory vnode, that is the parent directory of covered vnode) while holding an exclusive vnode lock on covering vnode. A simplified scenario: root fs var fs / A / (/var) D /var B /log (/var/log) E vfs lock C vfs lock F Within each file system, the lock order is clear: C->A->B and F->D->E When traversing across mounts, the system can choose between two lock orders, but everything must then follow that lock order: L1: C->A->B | +->F->D->E L2: F->D->E | +->C->A->B The lookup() process for namei("/var") mixes those two lock orders: VOP_LOOKUP() obtains B while A is held vfs_busy() obtains a shared lock on F while A and B are held (follows L1, violates L2) vput() releases lock on B VOP_UNLOCK() releases lock on A VFS_ROOT() obtains lock on D while shared lock on F is held vfs_unbusy() releases shared lock on F vn_lock() obtains lock on A while D is held (violates L1, follows L2) dounmount() follows L1 (B is locked while F is drained). Without unmount activity, vfs_busy() will always succeed without blocking and the deadlock isn't triggered (the system behaves as if L2 is followed). With unmount, you can get 4 processes in a deadlock: p1: holds D, want A (in lookup()) p2: holds shared lock on F, want D (in VFS_ROOT()) p3: holds B, want drain lock on F (in dounmount()) p4: holds A, want B (in VOP_LOOKUP()) You can have more than one instance of p2. The reversal was introduced in revision 1.81 of src/sys/kern/vfs_lookup.c and MFCed to revision 1.80.2.1, probably to avoid a cascade of vnode locks when nfs servers are dead (VFS_ROOT() just hangs) spreading to the root fs root vnode. - Tor Egge To fix the LOR, ups@ noted that when crossing the mount point, ni_dvp is actually not used by the callers of namei. Thus, placeholder deadfs vnode vp_crossmp is introduced that is filled into ni_dvp. Idea by: ups Reviewed by: tegge, ups, jeff, rwatson (mac interaction) Tested by: Peter Holm MFC after: 2 weeks
2007-01-22 11:25:22 +00:00
/*
* Placeholder vnode for mp traversal
*/
static struct vnode *vp_crossmp;
Untangle vfsinit() a bit. Use seperate sysinit functions rather than having a super-function calling bits all over the place.
2000-12-06 07:09:08 +00:00
static void
nameiinit(void *dummy __unused)
{
Rather than ignoring any error return from getnewvnode() in nameiinit(), explicitly test and panic. This should not ever happen, but if it does, this is a preferred failure mode to a NULL pointer dereference in kernel. Coverity CID: 1716 Found with: Coverity Prevent(tm)
2007-03-31 16:08:50 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
namei_zone = uma_zcreate("NAMEI", MAXPATHLEN, NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
Add dedicated routines to toggle lockmgr flags such as LK_NOSHARE and LK_CANRECURSE after a lock is created. Use them to implement macros that otherwise manipulated the flags directly. Assert that the associated lockmgr lock is exclusively locked by the current thread when manipulating these flags to ensure the flag updates are safe. This last change required some minor shuffling in a few filesystems to exclusively lock a brand new vnode slightly earlier. Reviewed by: kib MFC after: 3 days
2010-08-20 19:46:50 +00:00
getnewvnode("crossmp", NULL, &dead_vnodeops, &vp_crossmp);
vn_lock(vp_crossmp, LK_EXCLUSIVE);
Introduce some functions in the vnode locks namespace and in the ffs namespace in order to handle lockmgr fields in a controlled way instead than spreading all around bogus stubs: - VN_LOCK_AREC() allows lock recursion for a specified vnode - VN_LOCK_ASHARE() allows lock sharing for a specified vnode In FFS land: - BUF_AREC() allows lock recursion for a specified buffer lock - BUF_NOREC() disallows recursion for a specified buffer lock Side note: union_subr.c::unionfs_node_update() is the only other function directly handling lockmgr fields. As this is not simple to fix, it has been left behind as "sole" exception.
2008-02-24 16:38:58 +00:00
VN_LOCK_ASHARE(vp_crossmp);
Add dedicated routines to toggle lockmgr flags such as LK_NOSHARE and LK_CANRECURSE after a lock is created. Use them to implement macros that otherwise manipulated the flags directly. Assert that the associated lockmgr lock is exclusively locked by the current thread when manipulating these flags to ensure the flag updates are safe. This last change required some minor shuffling in a few filesystems to exclusively lock a brand new vnode slightly earlier. Reviewed by: kib MFC after: 3 days
2010-08-20 19:46:50 +00:00
VOP_UNLOCK(vp_crossmp, 0);
Untangle vfsinit() a bit. Use seperate sysinit functions rather than having a super-function calling bits all over the place.
2000-12-06 07:09:08 +00:00
}
In keeping with style(9)'s recommendations on macros, use a ';' after each SYSINIT() macro invocation. This makes a number of lightweight C parsers much happier with the FreeBSD kernel source, including cflow's prcc and lxr. MFC after: 1 month Discussed with: imp, rink
2008-03-16 10:58:09 +00:00
SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_SECOND, nameiinit, NULL);
Untangle vfsinit() a bit. Use seperate sysinit functions rather than having a super-function calling bits all over the place.
2000-12-06 07:09:08 +00:00
Enable shared locks for path name lookups on supported filesystems (NFS client, UFS, and ZFS) by default.
2008-10-01 19:25:37 +00:00
static int lookup_shared = 1;
Pull in r267961 and r267973 again. Fix for issues reported will follow.
2014-06-28 03:56:17 +00:00
SYSCTL_INT(_vfs, OID_AUTO, lookup_shared, CTLFLAG_RWTUN, &lookup_shared, 0,
- Include opt_vfs.h for LOOKUP_SHARED. - Control the behavior of shared lookups with the lookup_shared sysctl which has its default behavior set via the LOOKUP_SHARED option.
2005-04-03 23:50:20 +00:00
"Enables/Disables shared locks for path name translation");
Move the comment describing namei(9) back to namei()'s definition. MFC after: 3 days
2015-07-05 22:56:41 +00:00
static void
namei_cleanup_cnp(struct componentname *cnp)
{
uma_zfree(namei_zone, cnp->cn_pnbuf);
#ifdef DIAGNOSTIC
cnp->cn_pnbuf = NULL;
cnp->cn_nameptr = NULL;
#endif
}
vfs: avoid spurious vref/vrele for absolute lookups namei used to vref fd_cdir, which was immediatley vrele'd on entry to the loop. Check for absolute lookup and vref the right vnode the first time. Reviewed by: kib
2015-07-09 15:06:58 +00:00
static int
namei_handle_root(struct nameidata *ndp, struct vnode **dpp)
{
vfs: cosmetic changes to namei and namei_handle_root - don't initialize cnp during declaration - don't test error/!error, compare to 0 instead
2015-07-09 17:17:26 +00:00
struct componentname *cnp;
vfs: avoid spurious vref/vrele for absolute lookups namei used to vref fd_cdir, which was immediatley vrele'd on entry to the loop. Check for absolute lookup and vref the right vnode the first time. Reviewed by: kib
2015-07-09 15:06:58 +00:00
vfs: cosmetic changes to namei and namei_handle_root - don't initialize cnp during declaration - don't test error/!error, compare to 0 instead
2015-07-09 17:17:26 +00:00
cnp = &ndp->ni_cnd;
vfs: avoid spurious vref/vrele for absolute lookups namei used to vref fd_cdir, which was immediatley vrele'd on entry to the loop. Check for absolute lookup and vref the right vnode the first time. Reviewed by: kib
2015-07-09 15:06:58 +00:00
if (ndp->ni_strictrelative != 0) {
#ifdef KTRACE
if (KTRPOINT(curthread, KTR_CAPFAIL))
ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
#endif
return (ENOTCAPABLE);
}
while (*(cnp->cn_nameptr) == '/') {
cnp->cn_nameptr++;
ndp->ni_pathlen--;
}
*dpp = ndp->ni_rootdir;
VREF(*dpp);
return (0);
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
We now spell "inode" as "vnode" in the VFS layer, so update comment for new world order. MFC after: 3 days Pointed out by: mckusick
2006-08-05 21:08:47 +00:00
* Convert a pathname into a pointer to a locked vnode.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*
* The FOLLOW flag is set when symbolic links are to be followed
* when they occur at the end of the name translation process.
* Symbolic links are always followed for all other pathname
* components other than the last.
*
* The segflg defines whether the name is to be copied from user
* space or kernel space.
*
* Overall outline of namei:
*
* copy in name
* get starting directory
* while (!done && !error) {
* call lookup to search path.
* if symbolic link, massage name in buffer and continue
* }
*/
int
Remove register, use ANSI function headers.
2006-08-05 21:40:59 +00:00
namei(struct nameidata *ndp)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Remove register, use ANSI function headers.
2006-08-05 21:40:59 +00:00
struct filedesc *fdp; /* pointer to file descriptor state */
char *cp; /* pointer into pathname argument */
struct vnode *dp; /* the directory we are searching */
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
struct iovec aiov; /* uio for reading symbolic links */
struct uio auio;
vfs: simplify error handling in namei The logic is reorganised so that there is one exit point prior to the lookup loop. This is an intermediate step to making audit logging functions use found vnode instead of translating ni_dirfd on their own. ni_startdir validation is removed. The only in-tree consumer is nfs which already makes sure it is a directory. Reviewed by: kib
2015-07-09 16:32:58 +00:00
int error, linklen, startdir_used;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
struct componentname *cnp = &ndp->ni_cnd;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
struct thread *td = cnp->cn_thread;
struct proc *p = td->td_proc;
Assert Giant in namei(). Bugs have been reported in which, following a sleep() call waking up in namei(), a later assertion triggers that Giant is not held. By asserting Giant at the start of namei(), we can know that if that assertion triggers, Giant is lost during the call to namei(), and not before.
2004-08-04 18:39:07 +00:00
- Change namei() to use td_ucred instead of p_ucred. - Change the hack in access() that uses a temporary credential to set td_ucred to the temp cred instead of p_ucred.
2002-02-27 19:15:29 +00:00
ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_thread->td_ucred;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
KASSERT(cnp->cn_cred && p, ("namei: bad cred/proc"));
Split DIAGNOSTIC -> DIAGNOSTIC, INVARIANTS, and INVARIANT_SUPPORT as discussed on -hackers. Introduce 'KASSERT(assertion, ("panic message", args))' for simple check + panic. Reviewed by: msmith
1999-01-08 17:31:30 +00:00
KASSERT((cnp->cn_nameiop & (~OPMASK)) == 0,
KNFize, by bde.
1999-01-10 01:58:29 +00:00
("namei: nameiop contaminated with flags"));
Split DIAGNOSTIC -> DIAGNOSTIC, INVARIANTS, and INVARIANT_SUPPORT as discussed on -hackers. Introduce 'KASSERT(assertion, ("panic message", args))' for simple check + panic. Reviewed by: msmith
1999-01-08 17:31:30 +00:00
KASSERT((cnp->cn_flags & OPMASK) == 0,
KNFize, by bde.
1999-01-10 01:58:29 +00:00
("namei: flags contaminated with nameiops"));
vfs: simplify error handling in namei The logic is reorganised so that there is one exit point prior to the lookup loop. This is an intermediate step to making audit logging functions use found vnode instead of translating ni_dirfd on their own. ni_startdir validation is removed. The only in-tree consumer is nfs which already makes sure it is a directory. Reviewed by: kib
2015-07-09 16:32:58 +00:00
MPASS(ndp->ni_startdir == NULL || ndp->ni_startdir->v_type == VDIR ||
ndp->ni_startdir->v_type == VBAD);
- Include opt_vfs.h for LOOKUP_SHARED. - Control the behavior of shared lookups with the lookup_shared sysctl which has its default behavior set via the LOOKUP_SHARED option.
2005-04-03 23:50:20 +00:00
if (!lookup_shared)
cnp->cn_flags &= ~LOCKSHARED;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
fdp = p->p_fd;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Let vfs_lookup() return ENOTDIR if the path has a trailing slash and the last component is a symlink to something that isn't a directory. We introduce a new namei flag, TRAILINGSLASH, which is set by lookup() if the last component is followed by a slash. The trailing slash is then stripped, as before. If the final component is a symlink, lookup() will return to namei(), which will expand the symlink and call lookup() with the new path. When all symlinks have been resolved, lookup() checks if the TRAILINGSLASH flag is set, and if it is, and the vnode it ended up with is not a directory, it returns ENOTDIR. PR: kern/21768 Submitted by: Eygene Ryabinkin <rea-fbsd@codelabs.ru> MFC after: 3 weeks
2009-05-29 10:02:44 +00:00
/* We will set this ourselves if we need it. */
cnp->cn_flags &= ~TRAILINGSLASH;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
* Get a buffer for the name to be translated, and copy the
* name into the buffer.
*/
if ((cnp->cn_flags & HASBUF) == 0)
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
cnp->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (ndp->ni_segflg == UIO_SYSSPACE)
error = copystr(ndp->ni_dirp, cnp->cn_pnbuf,
This commit fixes various 64bit portability problems required for FreeBSD/alpha. The most significant item is to change the command argument to ioctl functions from int to u_long. This change brings us inline with various other BSD versions. Driver writers may like to use (__FreeBSD_version == 300003) to detect this change. The prototype FreeBSD/alpha machdep will follow in a couple of days time.
1998-06-07 17:13:14 +00:00
MAXPATHLEN, (size_t *)&ndp->ni_pathlen);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
else
error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf,
This commit fixes various 64bit portability problems required for FreeBSD/alpha. The most significant item is to change the command argument to ioctl functions from int to u_long. This change brings us inline with various other BSD versions. Driver writers may like to use (__FreeBSD_version == 300003) to detect this change. The prototype FreeBSD/alpha machdep will follow in a couple of days time.
1998-06-07 17:13:14 +00:00
MAXPATHLEN, (size_t *)&ndp->ni_pathlen);
Don't allow empty pathnames. POSIX standard. Most of the standard utilities that depended on (or were broken in a different way by) the old behaviour of interpreting "" as "." were fixed a year or two ago. There is still a fairly harmless bug in tar and a harmless bug in gzip. Tar apparently replaces "/" by "" when it strips leading slashes.
1996-12-01 16:05:44 +00:00
/*
* Don't allow empty pathnames.
*/
vfs: cosmetic changes to namei and namei_handle_root - don't initialize cnp during declaration - don't test error/!error, compare to 0 instead
2015-07-09 17:17:26 +00:00
if (error == 0 && *cnp->cn_pnbuf == '\0')
Don't allow empty pathnames. POSIX standard. Most of the standard utilities that depended on (or were broken in a different way by) the old behaviour of interpreting "" as "." were fixed a year or two ago. There is still a fairly harmless bug in tar and a harmless bug in gzip. Tar apparently replaces "/" by "" when it strips leading slashes.
1996-12-01 16:05:44 +00:00
error = ENOENT;
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
#ifdef CAPABILITY_MODE
/*
* In capability mode, lookups must be "strictly relative" (i.e.
* not an absolute path, and not containing '..' components) to
* a real file descriptor, not the pseudo-descriptor AT_FDCWD.
*/
Do not override the ENOENT error for the empty path, or EFAULT errors from copyins, with the relative lookup check. Discussed with: rwatson Sponsored by: The FreeBSD Foundation MFC after: 1 week
2013-08-05 19:42:03 +00:00
if (error == 0 && IN_CAPABILITY_MODE(td) &&
(cnp->cn_flags & NOCAPCHECK) == 0) {
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
ndp->ni_strictrelative = 1;
Revisit the capability failure trace points. The initial implementation only logged instances where an operation on a file descriptor required capabilities which the file descriptor did not have. By adding a type enum to struct ktr_cap_fail, we can catch other types of capability failures as well, such as disallowed system calls or attempts to wrap a file descriptor with more capabilities than it had to begin with.
2011-10-18 07:28:58 +00:00
if (ndp->ni_dirfd == AT_FDCWD) {
#ifdef KTRACE
if (KTRPOINT(td, KTR_CAPFAIL))
Fix panic in ktrcapfail() when no capability rights are passed. While here, correct all consumers to pass NULL instead of 0 as we pass capability rights as pointers now, not uint64_t. Reported by: Daniel Peyrolon Tested by: Daniel Peyrolon Approved by: re (marius)
2013-09-18 19:26:08 +00:00
ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
Revisit the capability failure trace points. The initial implementation only logged instances where an operation on a file descriptor required capabilities which the file descriptor did not have. By adding a type enum to struct ktr_cap_fail, we can catch other types of capability failures as well, such as disallowed system calls or attempts to wrap a file descriptor with more capabilities than it had to begin with.
2011-10-18 07:28:58 +00:00
#endif
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
error = ECAPMODE;
Revisit the capability failure trace points. The initial implementation only logged instances where an operation on a file descriptor required capabilities which the file descriptor did not have. By adding a type enum to struct ktr_cap_fail, we can catch other types of capability failures as well, such as disallowed system calls or attempts to wrap a file descriptor with more capabilities than it had to begin with.
2011-10-18 07:28:58 +00:00
}
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
}
#endif
vfs: cosmetic changes to namei and namei_handle_root - don't initialize cnp during declaration - don't test error/!error, compare to 0 instead
2015-07-09 17:17:26 +00:00
if (error != 0) {
Plug a memory leak in case of failed lookups in capability mode. Put common cnp cleanup into one function and use it for this purpose. MFC after: 1 week
2014-08-24 12:51:12 +00:00
namei_cleanup_cnp(cnp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
ndp->ni_vp = NULL;
return (error);
}
ndp->ni_loopcnt = 0;
#ifdef KTRACE
Catch up to changes in ktrace API.
2002-06-07 05:37:18 +00:00
if (KTRPOINT(td, KTR_NAMEI)) {
KASSERT(cnp->cn_thread == curthread,
("namei not using curthread"));
ktrnamei(cnp->cn_pnbuf);
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#endif
/*
* Get starting point for the translation.
*/
Replace custom file descriptor array sleep lock constructed using a mutex and flags with an sxlock. This leads to a significant and measurable performance improvement as a result of access to shared locking for frequent lookup operations, reduced general overhead, and reduced overhead in the event of contention. All of these are imported for threaded applications where simultaneous access to a shared file descriptor array occurs frequently. Kris has reported 2x-4x transaction rate improvements on 8-core MySQL benchmarks; smaller improvements can be expected for many workloads as a result of reduced overhead. - Generally eliminate the distinction between "fast" and regular acquisisition of the filedesc lock; the plan is that they will now all be fast. Change all locking instances to either shared or exclusive locks. - Correct a bug (pointed out by kib) in fdfree() where previously msleep() was called without the mutex held; sx_sleep() is now always called with the sxlock held exclusively. - Universally hold the struct file lock over changes to struct file, rather than the filedesc lock or no lock. Always update the f_ops field last. A further memory barrier is required here in the future (discussed with jhb). - Improve locking and reference management in linux_at(), which fails to properly acquire vnode references before using vnode pointers. Annotate improper use of vn_fullpath(), which will be replaced at a future date. In fcntl(), we conservatively acquire an exclusive lock, even though in some cases a shared lock may be sufficient, which should be revisited. The dropping of the filedesc lock in fdgrowtable() is no longer required as the sxlock can be held over the sleep operation; we should consider removing that (pointed out by attilio). Tested by: kris Discussed with: jhb, kris, attilio, jeff
2007-04-04 09:11:34 +00:00
FILEDESC_SLOCK(fdp);
Make the rootdir handling more consistent. Now, processes always have a root vnode associated with them, and no special checks for the null case are needed. Submitted by: terry@freebsd.org
1998-02-15 04:17:09 +00:00
ndp->ni_rootdir = fdp->fd_rdir;
vfs: plug a use-after-free of fd_rdir in namei fd_rdir vnode was stored in ni_rootdir without refing it in any way, after which the filedsc lock was being dropped. The vnode could have been freed by mountcheckdirs or another thread doing chroot. VREF the vnode while the lock is held. Reviewed by: kib MFC after: 1 week
2015-07-09 15:06:24 +00:00
VREF(ndp->ni_rootdir);
Fix a hole in jail(2). Noticed by: Alexander Bezroutchko <abb@zenon.net>
1999-09-25 14:14:21 +00:00
ndp->ni_topdir = fdp->fd_jdir;
Make the rootdir handling more consistent. Now, processes always have a root vnode associated with them, and no special checks for the null case are needed. Submitted by: terry@freebsd.org
1998-02-15 04:17:09 +00:00
IFp4 @208451: Fix path handling for *at() syscalls. Before the change directory descriptor was totally ignored, so the relative path argument was appended to current working directory path and not to the path provided by descriptor, thus wrong paths were stored in audit logs. Now that we use directory descriptor in vfs_lookup, move AUDIT_ARG_UPATH1() and AUDIT_ARG_UPATH2() calls to the place where we hold file descriptors table lock, so we are sure paths will be resolved according to the same directory in audit record and in actual operation. Sponsored by: FreeBSD Foundation (auditdistd) Reviewed by: rwatson MFC after: 2 weeks
2012-11-30 23:18:49 +00:00
/*
* If we are auditing the kernel pathname, save the user pathname.
*/
if (cnp->cn_flags & AUDITVNODE1)
Fix one more compilation issue.
2012-12-01 08:59:36 +00:00
AUDIT_ARG_UPATH1(td, ndp->ni_dirfd, cnp->cn_pnbuf);
IFp4 @208451: Fix path handling for *at() syscalls. Before the change directory descriptor was totally ignored, so the relative path argument was appended to current working directory path and not to the path provided by descriptor, thus wrong paths were stored in audit logs. Now that we use directory descriptor in vfs_lookup, move AUDIT_ARG_UPATH1() and AUDIT_ARG_UPATH2() calls to the place where we hold file descriptors table lock, so we are sure paths will be resolved according to the same directory in audit record and in actual operation. Sponsored by: FreeBSD Foundation (auditdistd) Reviewed by: rwatson MFC after: 2 weeks
2012-11-30 23:18:49 +00:00
if (cnp->cn_flags & AUDITVNODE2)
Fix one more compilation issue.
2012-12-01 08:59:36 +00:00
AUDIT_ARG_UPATH2(td, ndp->ni_dirfd, cnp->cn_pnbuf);
IFp4 @208451: Fix path handling for *at() syscalls. Before the change directory descriptor was totally ignored, so the relative path argument was appended to current working directory path and not to the path provided by descriptor, thus wrong paths were stored in audit logs. Now that we use directory descriptor in vfs_lookup, move AUDIT_ARG_UPATH1() and AUDIT_ARG_UPATH2() calls to the place where we hold file descriptors table lock, so we are sure paths will be resolved according to the same directory in audit record and in actual operation. Sponsored by: FreeBSD Foundation (auditdistd) Reviewed by: rwatson MFC after: 2 weeks
2012-11-30 23:18:49 +00:00
vfs: simplify error handling in namei The logic is reorganised so that there is one exit point prior to the lookup loop. This is an intermediate step to making audit logging functions use found vnode instead of translating ni_dirfd on their own. ni_startdir validation is removed. The only in-tree consumer is nfs which already makes sure it is a directory. Reviewed by: kib
2015-07-09 16:32:58 +00:00
startdir_used = 0;
Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes. This bring huge amount of changes, I'll enumerate only user-visible changes: - Delegated Administration Allows regular users to perform ZFS operations, like file system creation, snapshot creation, etc. - L2ARC Level 2 cache for ZFS - allows to use additional disks for cache. Huge performance improvements mostly for random read of mostly static content. - slog Allow to use additional disks for ZFS Intent Log to speed up operations like fsync(2). - vfs.zfs.super_owner Allows regular users to perform privileged operations on files stored on ZFS file systems owned by him. Very careful with this one. - chflags(2) Not all the flags are supported. This still needs work. - ZFSBoot Support to boot off of ZFS pool. Not finished, AFAIK. Submitted by: dfr - Snapshot properties - New failure modes Before if write requested failed, system paniced. Now one can select from one of three failure modes: - panic - panic on write error - wait - wait for disk to reappear - continue - serve read requests if possible, block write requests - Refquota, refreservation properties Just quota and reservation properties, but don't count space consumed by children file systems, clones and snapshots. - Sparse volumes ZVOLs that don't reserve space in the pool. - External attributes Compatible with extattr(2). - NFSv4-ACLs Not sure about the status, might not be complete yet. Submitted by: trasz - Creation-time properties - Regression tests for zpool(8) command. Obtained from: OpenSolaris
2008-11-17 20:49:29 +00:00
dp = NULL;
vfs: avoid spurious vref/vrele for absolute lookups namei used to vref fd_cdir, which was immediatley vrele'd on entry to the loop. Check for absolute lookup and vref the right vnode the first time. Reviewed by: kib
2015-07-09 15:06:58 +00:00
cnp->cn_nameptr = cnp->cn_pnbuf;
if (cnp->cn_pnbuf[0] == '/') {
error = namei_handle_root(ndp, &dp);
} else {
Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes. This bring huge amount of changes, I'll enumerate only user-visible changes: - Delegated Administration Allows regular users to perform ZFS operations, like file system creation, snapshot creation, etc. - L2ARC Level 2 cache for ZFS - allows to use additional disks for cache. Huge performance improvements mostly for random read of mostly static content. - slog Allow to use additional disks for ZFS Intent Log to speed up operations like fsync(2). - vfs.zfs.super_owner Allows regular users to perform privileged operations on files stored on ZFS file systems owned by him. Very careful with this one. - chflags(2) Not all the flags are supported. This still needs work. - ZFSBoot Support to boot off of ZFS pool. Not finished, AFAIK. Submitted by: dfr - Snapshot properties - New failure modes Before if write requested failed, system paniced. Now one can select from one of three failure modes: - panic - panic on write error - wait - wait for disk to reappear - continue - serve read requests if possible, block write requests - Refquota, refreservation properties Just quota and reservation properties, but don't count space consumed by children file systems, clones and snapshots. - Sparse volumes ZVOLs that don't reserve space in the pool. - External attributes Compatible with extattr(2). - NFSv4-ACLs Not sure about the status, might not be complete yet. Submitted by: trasz - Creation-time properties - Regression tests for zpool(8) command. Obtained from: OpenSolaris
2008-11-17 20:49:29 +00:00
if (ndp->ni_startdir != NULL) {
dp = ndp->ni_startdir;
vfs: simplify error handling in namei The logic is reorganised so that there is one exit point prior to the lookup loop. This is an intermediate step to making audit logging functions use found vnode instead of translating ni_dirfd on their own. ni_startdir validation is removed. The only in-tree consumer is nfs which already makes sure it is a directory. Reviewed by: kib
2015-07-09 16:32:58 +00:00
startdir_used = 1;
} else if (ndp->ni_dirfd == AT_FDCWD) {
dp = fdp->fd_cdir;
VREF(dp);
} else {
Change the cap_rights_t type from uint64_t to a structure that we can extend in the future in a backward compatible (API and ABI) way. The cap_rights_t represents capability rights. We used to use one bit to represent one right, but we are running out of spare bits. Currently the new structure provides place for 114 rights (so 50 more than the previous cap_rights_t), but it is possible to grow the structure to hold at least 285 rights, although we can make it even larger if 285 rights won't be enough. The structure definition looks like this: struct cap_rights { uint64_t cr_rights[CAP_RIGHTS_VERSION + 2]; }; The initial CAP_RIGHTS_VERSION is 0. The top two bits in the first element of the cr_rights[] array contain total number of elements in the array - 2. This means if those two bits are equal to 0, we have 2 array elements. The top two bits in all remaining array elements should be 0. The next five bits in all array elements contain array index. Only one bit is used and bit position in this five-bits range defines array index. This means there can be at most five array elements in the future. To define new right the CAPRIGHT() macro must be used. The macro takes two arguments - an array index and a bit to set, eg. #define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL) We still support aliases that combine few rights, but the rights have to belong to the same array element, eg: #define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL) #define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL) #define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP) There is new API to manage the new cap_rights_t structure: cap_rights_t *cap_rights_init(cap_rights_t *rights, ...); void cap_rights_set(cap_rights_t *rights, ...); void cap_rights_clear(cap_rights_t *rights, ...); bool cap_rights_is_set(const cap_rights_t *rights, ...); bool cap_rights_is_valid(const cap_rights_t *rights); void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src); void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src); bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little); Capability rights to the cap_rights_init(), cap_rights_set(), cap_rights_clear() and cap_rights_is_set() functions are provided by separating them with commas, eg: cap_rights_t rights; cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT); There is no need to terminate the list of rights, as those functions are actually macros that take care of the termination, eg: #define cap_rights_set(rights, ...) \ __cap_rights_set((rights), __VA_ARGS__, 0ULL) void __cap_rights_set(cap_rights_t *rights, ...); Thanks to using one bit as an array index we can assert in those functions that there are no two rights belonging to different array elements provided together. For example this is illegal and will be detected, because CAP_LOOKUP belongs to element 0 and CAP_PDKILL to element 1: cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL); Providing several rights that belongs to the same array's element this way is correct, but is not advised. It should only be used for aliases definition. This commit also breaks compatibility with some existing Capsicum system calls, but I see no other way to do that. This should be fine as Capsicum is still experimental and this change is not going to 9.x. Sponsored by: The FreeBSD Foundation
2013-09-05 00:09:56 +00:00
cap_rights_t rights;
rights = ndp->ni_rightsneeded;
cap_rights_set(&rights, CAP_LOOKUP);
Audit file descriptors passed to fooat(2) system calls, which are used instead of the root/current working directory as the starting point for lookups. Up to two such descriptors can be audited. Add audit record BSM encoding for fooat(2). Note: due to an error in the OpenBSM 1.1p1 configuration file, a further change is required to that file in order to fix openat(2) auditing. Approved by: re (kib) Reviewed by: rdivacky (fooat(2) portions) Obtained from: TrustedBSD Project MFC after: 1 month
2009-07-28 21:39:58 +00:00
if (cnp->cn_flags & AUDITVNODE1)
AUDIT_ARG_ATFD1(ndp->ni_dirfd);
if (cnp->cn_flags & AUDITVNODE2)
AUDIT_ARG_ATFD2(ndp->ni_dirfd);
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
error = fgetvp_rights(td, ndp->ni_dirfd,
Change the cap_rights_t type from uint64_t to a structure that we can extend in the future in a backward compatible (API and ABI) way. The cap_rights_t represents capability rights. We used to use one bit to represent one right, but we are running out of spare bits. Currently the new structure provides place for 114 rights (so 50 more than the previous cap_rights_t), but it is possible to grow the structure to hold at least 285 rights, although we can make it even larger if 285 rights won't be enough. The structure definition looks like this: struct cap_rights { uint64_t cr_rights[CAP_RIGHTS_VERSION + 2]; }; The initial CAP_RIGHTS_VERSION is 0. The top two bits in the first element of the cr_rights[] array contain total number of elements in the array - 2. This means if those two bits are equal to 0, we have 2 array elements. The top two bits in all remaining array elements should be 0. The next five bits in all array elements contain array index. Only one bit is used and bit position in this five-bits range defines array index. This means there can be at most five array elements in the future. To define new right the CAPRIGHT() macro must be used. The macro takes two arguments - an array index and a bit to set, eg. #define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL) We still support aliases that combine few rights, but the rights have to belong to the same array element, eg: #define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL) #define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL) #define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP) There is new API to manage the new cap_rights_t structure: cap_rights_t *cap_rights_init(cap_rights_t *rights, ...); void cap_rights_set(cap_rights_t *rights, ...); void cap_rights_clear(cap_rights_t *rights, ...); bool cap_rights_is_set(const cap_rights_t *rights, ...); bool cap_rights_is_valid(const cap_rights_t *rights); void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src); void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src); bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little); Capability rights to the cap_rights_init(), cap_rights_set(), cap_rights_clear() and cap_rights_is_set() functions are provided by separating them with commas, eg: cap_rights_t rights; cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT); There is no need to terminate the list of rights, as those functions are actually macros that take care of the termination, eg: #define cap_rights_set(rights, ...) \ __cap_rights_set((rights), __VA_ARGS__, 0ULL) void __cap_rights_set(cap_rights_t *rights, ...); Thanks to using one bit as an array index we can assert in those functions that there are no two rights belonging to different array elements provided together. For example this is illegal and will be detected, because CAP_LOOKUP belongs to element 0 and CAP_PDKILL to element 1: cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL); Providing several rights that belongs to the same array's element this way is correct, but is not advised. It should only be used for aliases definition. This commit also breaks compatibility with some existing Capsicum system calls, but I see no other way to do that. This should be fine as Capsicum is still experimental and this change is not going to 9.x. Sponsored by: The FreeBSD Foundation
2013-09-05 00:09:56 +00:00
&rights, &ndp->ni_filecaps, &dp);
Properly return ENOTDIR when calling *at() on a non-vnode. We already properly return ENOTDIR when calling *at() on a non-directory vnode, but it turns out that if you call it on a socket, we see EINVAL. Patch up namei to properly translate this to ENOTDIR.
2015-08-12 16:17:00 +00:00
if (error == EINVAL)
error = ENOTDIR;
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
#ifdef CAPABILITIES
/*
Merge Capsicum overhaul: - Capability is no longer separate descriptor type. Now every descriptor has set of its own capability rights. - The cap_new(2) system call is left, but it is no longer documented and should not be used in new code. - The new syscall cap_rights_limit(2) should be used instead of cap_new(2), which limits capability rights of the given descriptor without creating a new one. - The cap_getrights(2) syscall is renamed to cap_rights_get(2). - If CAP_IOCTL capability right is present we can further reduce allowed ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed ioctls can be retrived with cap_ioctls_get(2) syscall. - If CAP_FCNTL capability right is present we can further reduce fcntls that can be used with the new cap_fcntls_limit(2) syscall and retrive them with cap_fcntls_get(2). - To support ioctl and fcntl white-listing the filedesc structure was heavly modified. - The audit subsystem, kdump and procstat tools were updated to recognize new syscalls. - Capability rights were revised and eventhough I tried hard to provide backward API and ABI compatibility there are some incompatible changes that are described in detail below: CAP_CREATE old behaviour: - Allow for openat(2)+O_CREAT. - Allow for linkat(2). - Allow for symlinkat(2). CAP_CREATE new behaviour: - Allow for openat(2)+O_CREAT. Added CAP_LINKAT: - Allow for linkat(2). ABI: Reuses CAP_RMDIR bit. - Allow to be target for renameat(2). Added CAP_SYMLINKAT: - Allow for symlinkat(2). Removed CAP_DELETE. Old behaviour: - Allow for unlinkat(2) when removing non-directory object. - Allow to be source for renameat(2). Removed CAP_RMDIR. Old behaviour: - Allow for unlinkat(2) when removing directory. Added CAP_RENAMEAT: - Required for source directory for the renameat(2) syscall. Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR): - Allow for unlinkat(2) on any object. - Required if target of renameat(2) exists and will be removed by this call. Removed CAP_MAPEXEC. CAP_MMAP old behaviour: - Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and PROT_WRITE. CAP_MMAP new behaviour: - Allow for mmap(2)+PROT_NONE. Added CAP_MMAP_R: - Allow for mmap(PROT_READ). Added CAP_MMAP_W: - Allow for mmap(PROT_WRITE). Added CAP_MMAP_X: - Allow for mmap(PROT_EXEC). Added CAP_MMAP_RW: - Allow for mmap(PROT_READ | PROT_WRITE). Added CAP_MMAP_RX: - Allow for mmap(PROT_READ | PROT_EXEC). Added CAP_MMAP_WX: - Allow for mmap(PROT_WRITE | PROT_EXEC). Added CAP_MMAP_RWX: - Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC). Renamed CAP_MKDIR to CAP_MKDIRAT. Renamed CAP_MKFIFO to CAP_MKFIFOAT. Renamed CAP_MKNODE to CAP_MKNODEAT. CAP_READ old behaviour: - Allow pread(2). - Disallow read(2), readv(2) (if there is no CAP_SEEK). CAP_READ new behaviour: - Allow read(2), readv(2). - Disallow pread(2) (CAP_SEEK was also required). CAP_WRITE old behaviour: - Allow pwrite(2). - Disallow write(2), writev(2) (if there is no CAP_SEEK). CAP_WRITE new behaviour: - Allow write(2), writev(2). - Disallow pwrite(2) (CAP_SEEK was also required). Added convinient defines: #define CAP_PREAD (CAP_SEEK | CAP_READ) #define CAP_PWRITE (CAP_SEEK | CAP_WRITE) #define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ) #define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE) #define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL) #define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W) #define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X) #define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X) #define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X) #define CAP_RECV CAP_READ #define CAP_SEND CAP_WRITE #define CAP_SOCK_CLIENT \ (CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \ CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN) #define CAP_SOCK_SERVER \ (CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \ CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \ CAP_SETSOCKOPT | CAP_SHUTDOWN) Added defines for backward API compatibility: #define CAP_MAPEXEC CAP_MMAP_X #define CAP_DELETE CAP_UNLINKAT #define CAP_MKDIR CAP_MKDIRAT #define CAP_RMDIR CAP_UNLINKAT #define CAP_MKFIFO CAP_MKFIFOAT #define CAP_MKNOD CAP_MKNODAT #define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER) Sponsored by: The FreeBSD Foundation Reviewed by: Christoph Mallon <christoph.mallon@gmx.de> Many aspects discussed with: rwatson, benl, jonathan ABI compatibility discussed with: kib
2013-03-02 00:53:12 +00:00
* If file descriptor doesn't have all rights,
* all lookups relative to it must also be
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
* strictly relative.
*/
Change the cap_rights_t type from uint64_t to a structure that we can extend in the future in a backward compatible (API and ABI) way. The cap_rights_t represents capability rights. We used to use one bit to represent one right, but we are running out of spare bits. Currently the new structure provides place for 114 rights (so 50 more than the previous cap_rights_t), but it is possible to grow the structure to hold at least 285 rights, although we can make it even larger if 285 rights won't be enough. The structure definition looks like this: struct cap_rights { uint64_t cr_rights[CAP_RIGHTS_VERSION + 2]; }; The initial CAP_RIGHTS_VERSION is 0. The top two bits in the first element of the cr_rights[] array contain total number of elements in the array - 2. This means if those two bits are equal to 0, we have 2 array elements. The top two bits in all remaining array elements should be 0. The next five bits in all array elements contain array index. Only one bit is used and bit position in this five-bits range defines array index. This means there can be at most five array elements in the future. To define new right the CAPRIGHT() macro must be used. The macro takes two arguments - an array index and a bit to set, eg. #define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL) We still support aliases that combine few rights, but the rights have to belong to the same array element, eg: #define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL) #define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL) #define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP) There is new API to manage the new cap_rights_t structure: cap_rights_t *cap_rights_init(cap_rights_t *rights, ...); void cap_rights_set(cap_rights_t *rights, ...); void cap_rights_clear(cap_rights_t *rights, ...); bool cap_rights_is_set(const cap_rights_t *rights, ...); bool cap_rights_is_valid(const cap_rights_t *rights); void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src); void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src); bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little); Capability rights to the cap_rights_init(), cap_rights_set(), cap_rights_clear() and cap_rights_is_set() functions are provided by separating them with commas, eg: cap_rights_t rights; cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT); There is no need to terminate the list of rights, as those functions are actually macros that take care of the termination, eg: #define cap_rights_set(rights, ...) \ __cap_rights_set((rights), __VA_ARGS__, 0ULL) void __cap_rights_set(cap_rights_t *rights, ...); Thanks to using one bit as an array index we can assert in those functions that there are no two rights belonging to different array elements provided together. For example this is illegal and will be detected, because CAP_LOOKUP belongs to element 0 and CAP_PDKILL to element 1: cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL); Providing several rights that belongs to the same array's element this way is correct, but is not advised. It should only be used for aliases definition. This commit also breaks compatibility with some existing Capsicum system calls, but I see no other way to do that. This should be fine as Capsicum is still experimental and this change is not going to 9.x. Sponsored by: The FreeBSD Foundation
2013-09-05 00:09:56 +00:00
CAP_ALL(&rights);
if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights,
&rights) ||
Merge Capsicum overhaul: - Capability is no longer separate descriptor type. Now every descriptor has set of its own capability rights. - The cap_new(2) system call is left, but it is no longer documented and should not be used in new code. - The new syscall cap_rights_limit(2) should be used instead of cap_new(2), which limits capability rights of the given descriptor without creating a new one. - The cap_getrights(2) syscall is renamed to cap_rights_get(2). - If CAP_IOCTL capability right is present we can further reduce allowed ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed ioctls can be retrived with cap_ioctls_get(2) syscall. - If CAP_FCNTL capability right is present we can further reduce fcntls that can be used with the new cap_fcntls_limit(2) syscall and retrive them with cap_fcntls_get(2). - To support ioctl and fcntl white-listing the filedesc structure was heavly modified. - The audit subsystem, kdump and procstat tools were updated to recognize new syscalls. - Capability rights were revised and eventhough I tried hard to provide backward API and ABI compatibility there are some incompatible changes that are described in detail below: CAP_CREATE old behaviour: - Allow for openat(2)+O_CREAT. - Allow for linkat(2). - Allow for symlinkat(2). CAP_CREATE new behaviour: - Allow for openat(2)+O_CREAT. Added CAP_LINKAT: - Allow for linkat(2). ABI: Reuses CAP_RMDIR bit. - Allow to be target for renameat(2). Added CAP_SYMLINKAT: - Allow for symlinkat(2). Removed CAP_DELETE. Old behaviour: - Allow for unlinkat(2) when removing non-directory object. - Allow to be source for renameat(2). Removed CAP_RMDIR. Old behaviour: - Allow for unlinkat(2) when removing directory. Added CAP_RENAMEAT: - Required for source directory for the renameat(2) syscall. Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR): - Allow for unlinkat(2) on any object. - Required if target of renameat(2) exists and will be removed by this call. Removed CAP_MAPEXEC. CAP_MMAP old behaviour: - Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and PROT_WRITE. CAP_MMAP new behaviour: - Allow for mmap(2)+PROT_NONE. Added CAP_MMAP_R: - Allow for mmap(PROT_READ). Added CAP_MMAP_W: - Allow for mmap(PROT_WRITE). Added CAP_MMAP_X: - Allow for mmap(PROT_EXEC). Added CAP_MMAP_RW: - Allow for mmap(PROT_READ | PROT_WRITE). Added CAP_MMAP_RX: - Allow for mmap(PROT_READ | PROT_EXEC). Added CAP_MMAP_WX: - Allow for mmap(PROT_WRITE | PROT_EXEC). Added CAP_MMAP_RWX: - Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC). Renamed CAP_MKDIR to CAP_MKDIRAT. Renamed CAP_MKFIFO to CAP_MKFIFOAT. Renamed CAP_MKNODE to CAP_MKNODEAT. CAP_READ old behaviour: - Allow pread(2). - Disallow read(2), readv(2) (if there is no CAP_SEEK). CAP_READ new behaviour: - Allow read(2), readv(2). - Disallow pread(2) (CAP_SEEK was also required). CAP_WRITE old behaviour: - Allow pwrite(2). - Disallow write(2), writev(2) (if there is no CAP_SEEK). CAP_WRITE new behaviour: - Allow write(2), writev(2). - Disallow pwrite(2) (CAP_SEEK was also required). Added convinient defines: #define CAP_PREAD (CAP_SEEK | CAP_READ) #define CAP_PWRITE (CAP_SEEK | CAP_WRITE) #define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ) #define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE) #define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL) #define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W) #define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X) #define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X) #define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X) #define CAP_RECV CAP_READ #define CAP_SEND CAP_WRITE #define CAP_SOCK_CLIENT \ (CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \ CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN) #define CAP_SOCK_SERVER \ (CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \ CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \ CAP_SETSOCKOPT | CAP_SHUTDOWN) Added defines for backward API compatibility: #define CAP_MAPEXEC CAP_MMAP_X #define CAP_DELETE CAP_UNLINKAT #define CAP_MKDIR CAP_MKDIRAT #define CAP_RMDIR CAP_UNLINKAT #define CAP_MKFIFO CAP_MKFIFOAT #define CAP_MKNOD CAP_MKNODAT #define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER) Sponsored by: The FreeBSD Foundation Reviewed by: Christoph Mallon <christoph.mallon@gmx.de> Many aspects discussed with: rwatson, benl, jonathan ABI compatibility discussed with: kib
2013-03-02 00:53:12 +00:00
ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL ||
ndp->ni_filecaps.fc_nioctls != -1) {
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
ndp->ni_strictrelative = 1;
Merge Capsicum overhaul: - Capability is no longer separate descriptor type. Now every descriptor has set of its own capability rights. - The cap_new(2) system call is left, but it is no longer documented and should not be used in new code. - The new syscall cap_rights_limit(2) should be used instead of cap_new(2), which limits capability rights of the given descriptor without creating a new one. - The cap_getrights(2) syscall is renamed to cap_rights_get(2). - If CAP_IOCTL capability right is present we can further reduce allowed ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed ioctls can be retrived with cap_ioctls_get(2) syscall. - If CAP_FCNTL capability right is present we can further reduce fcntls that can be used with the new cap_fcntls_limit(2) syscall and retrive them with cap_fcntls_get(2). - To support ioctl and fcntl white-listing the filedesc structure was heavly modified. - The audit subsystem, kdump and procstat tools were updated to recognize new syscalls. - Capability rights were revised and eventhough I tried hard to provide backward API and ABI compatibility there are some incompatible changes that are described in detail below: CAP_CREATE old behaviour: - Allow for openat(2)+O_CREAT. - Allow for linkat(2). - Allow for symlinkat(2). CAP_CREATE new behaviour: - Allow for openat(2)+O_CREAT. Added CAP_LINKAT: - Allow for linkat(2). ABI: Reuses CAP_RMDIR bit. - Allow to be target for renameat(2). Added CAP_SYMLINKAT: - Allow for symlinkat(2). Removed CAP_DELETE. Old behaviour: - Allow for unlinkat(2) when removing non-directory object. - Allow to be source for renameat(2). Removed CAP_RMDIR. Old behaviour: - Allow for unlinkat(2) when removing directory. Added CAP_RENAMEAT: - Required for source directory for the renameat(2) syscall. Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR): - Allow for unlinkat(2) on any object. - Required if target of renameat(2) exists and will be removed by this call. Removed CAP_MAPEXEC. CAP_MMAP old behaviour: - Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and PROT_WRITE. CAP_MMAP new behaviour: - Allow for mmap(2)+PROT_NONE. Added CAP_MMAP_R: - Allow for mmap(PROT_READ). Added CAP_MMAP_W: - Allow for mmap(PROT_WRITE). Added CAP_MMAP_X: - Allow for mmap(PROT_EXEC). Added CAP_MMAP_RW: - Allow for mmap(PROT_READ | PROT_WRITE). Added CAP_MMAP_RX: - Allow for mmap(PROT_READ | PROT_EXEC). Added CAP_MMAP_WX: - Allow for mmap(PROT_WRITE | PROT_EXEC). Added CAP_MMAP_RWX: - Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC). Renamed CAP_MKDIR to CAP_MKDIRAT. Renamed CAP_MKFIFO to CAP_MKFIFOAT. Renamed CAP_MKNODE to CAP_MKNODEAT. CAP_READ old behaviour: - Allow pread(2). - Disallow read(2), readv(2) (if there is no CAP_SEEK). CAP_READ new behaviour: - Allow read(2), readv(2). - Disallow pread(2) (CAP_SEEK was also required). CAP_WRITE old behaviour: - Allow pwrite(2). - Disallow write(2), writev(2) (if there is no CAP_SEEK). CAP_WRITE new behaviour: - Allow write(2), writev(2). - Disallow pwrite(2) (CAP_SEEK was also required). Added convinient defines: #define CAP_PREAD (CAP_SEEK | CAP_READ) #define CAP_PWRITE (CAP_SEEK | CAP_WRITE) #define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ) #define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE) #define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL) #define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W) #define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X) #define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X) #define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X) #define CAP_RECV CAP_READ #define CAP_SEND CAP_WRITE #define CAP_SOCK_CLIENT \ (CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \ CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN) #define CAP_SOCK_SERVER \ (CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \ CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \ CAP_SETSOCKOPT | CAP_SHUTDOWN) Added defines for backward API compatibility: #define CAP_MAPEXEC CAP_MMAP_X #define CAP_DELETE CAP_UNLINKAT #define CAP_MKDIR CAP_MKDIRAT #define CAP_RMDIR CAP_UNLINKAT #define CAP_MKFIFO CAP_MKFIFOAT #define CAP_MKNOD CAP_MKNODAT #define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER) Sponsored by: The FreeBSD Foundation Reviewed by: Christoph Mallon <christoph.mallon@gmx.de> Many aspects discussed with: rwatson, benl, jonathan ABI compatibility discussed with: kib
2013-03-02 00:53:12 +00:00
}
Second-to-last commit implementing Capsicum capabilities in the FreeBSD kernel for FreeBSD 9.0: Add a new capability mask argument to fget(9) and friends, allowing system call code to declare what capabilities are required when an integer file descriptor is converted into an in-kernel struct file *. With options CAPABILITIES compiled into the kernel, this enforces capability protection; without, this change is effectively a no-op. Some cases require special handling, such as mmap(2), which must preserve information about the maximum rights at the time of mapping in the memory map so that they can later be enforced in mprotect(2) -- this is done by narrowing the rights in the existing max_protection field used for similar purposes with file permissions. In namei(9), we assert that the code is not reached from within capability mode, as we're not yet ready to enforce namespace capabilities there. This will follow in a later commit. Update two capability names: CAP_EVENT and CAP_KEVENT become CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they represent. Approved by: re (bz) Submitted by: jonathan Sponsored by: Google Inc
2011-08-11 12:30:23 +00:00
#endif
Audit file descriptors passed to fooat(2) system calls, which are used instead of the root/current working directory as the starting point for lookups. Up to two such descriptors can be audited. Add audit record BSM encoding for fooat(2). Note: due to an error in the OpenBSM 1.1p1 configuration file, a further change is required to that file in order to fix openat(2) auditing. Approved by: re (kib) Reviewed by: rdivacky (fooat(2) portions) Obtained from: TrustedBSD Project MFC after: 1 month
2009-07-28 21:39:58 +00:00
}
vfs: simplify error handling in namei The logic is reorganised so that there is one exit point prior to the lookup loop. This is an intermediate step to making audit logging functions use found vnode instead of translating ni_dirfd on their own. ni_startdir validation is removed. The only in-tree consumer is nfs which already makes sure it is a directory. Reviewed by: kib
2015-07-09 16:32:58 +00:00
if (error == 0 && dp->v_type != VDIR)
error = ENOTDIR;
Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes. This bring huge amount of changes, I'll enumerate only user-visible changes: - Delegated Administration Allows regular users to perform ZFS operations, like file system creation, snapshot creation, etc. - L2ARC Level 2 cache for ZFS - allows to use additional disks for cache. Huge performance improvements mostly for random read of mostly static content. - slog Allow to use additional disks for ZFS Intent Log to speed up operations like fsync(2). - vfs.zfs.super_owner Allows regular users to perform privileged operations on files stored on ZFS file systems owned by him. Very careful with this one. - chflags(2) Not all the flags are supported. This still needs work. - ZFSBoot Support to boot off of ZFS pool. Not finished, AFAIK. Submitted by: dfr - Snapshot properties - New failure modes Before if write requested failed, system paniced. Now one can select from one of three failure modes: - panic - panic on write error - wait - wait for disk to reappear - continue - serve read requests if possible, block write requests - Refquota, refreservation properties Just quota and reservation properties, but don't count space consumed by children file systems, clones and snapshots. - Sparse volumes ZVOLs that don't reserve space in the pool. - External attributes Compatible with extattr(2). - NFSv4-ACLs Not sure about the status, might not be complete yet. Submitted by: trasz - Creation-time properties - Regression tests for zpool(8) command. Obtained from: OpenSolaris
2008-11-17 20:49:29 +00:00
}
vfs: simplify error handling in namei The logic is reorganised so that there is one exit point prior to the lookup loop. This is an intermediate step to making audit logging functions use found vnode instead of translating ni_dirfd on their own. ni_startdir validation is removed. The only in-tree consumer is nfs which already makes sure it is a directory. Reviewed by: kib
2015-07-09 16:32:58 +00:00
FILEDESC_SUNLOCK(fdp);
if (ndp->ni_startdir != NULL && !startdir_used)
vrele(ndp->ni_startdir);
if (error != 0) {
if (dp != NULL)
vrele(dp);
vfs: provide a common exit point in namei for error cases This shortens the function, adds the SDT_PROBE use for error cases and consistenly unrefs rootdir last. Reviewed by: kib MFC after: 2 weeks
2016-08-27 22:43:41 +00:00
goto out;
Add the support for the AT_FDCWD and fd-relative name lookups to the namei(9). Based on the submission by rdivacky, sponsored by Google Summer of Code 2007 Reviewed by: rwatson, rdivacky Tested by: pho
2008-03-31 12:01:21 +00:00
}
save some bytes by using more concise SDT_PROBE<n> instead of SDT_PROBE SDT_PROBE requires 5 parameters whereas SDT_PROBE<n> requires n parameters where n is typically smaller than 5. Perhaps SDT_PROBE should be made a private implementation detail. MFC after: 20 days
2015-09-28 12:14:16 +00:00
SDT_PROBE3(vfs, namei, lookup, entry, dp, cnp->cn_pnbuf,
cnp->cn_flags);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
for (;;) {
ndp->ni_startdir = dp;
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
error = lookup(ndp);
vfs: provide a common exit point in namei for error cases This shortens the function, adds the SDT_PROBE use for error cases and consistenly unrefs rootdir last. Reviewed by: kib MFC after: 2 weeks
2016-08-27 22:43:41 +00:00
if (error != 0)
goto out;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
Fix misleading comment. MFC after: 1 week
2009-05-29 09:52:13 +00:00
* If not a symbolic link, we're done.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
if ((cnp->cn_flags & ISSYMLINK) == 0) {
vfs: plug a use-after-free of fd_rdir in namei fd_rdir vnode was stored in ni_rootdir without refing it in any way, after which the filedsc lock was being dropped. The vnode could have been freed by mountcheckdirs or another thread doing chroot. VREF the vnode while the lock is held. Reviewed by: kib MFC after: 1 week
2015-07-09 15:06:24 +00:00
vrele(ndp->ni_rootdir);
Under #ifdef DIAGNOSTIC, NULL out componentname pointers if we free the pnbuf to increase the chances of detecting use of a free'd name buffer if SAVENAME or SAVESTART wasn't passed in. Curiously, running with these changes doesn't panic the kernel, and should.
2002-07-24 15:42:22 +00:00
if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0) {
Plug a memory leak in case of failed lookups in capability mode. Put common cnp cleanup into one function and use it for this purpose. MFC after: 1 week
2014-08-24 12:51:12 +00:00
namei_cleanup_cnp(cnp);
Under #ifdef DIAGNOSTIC, NULL out componentname pointers if we free the pnbuf to increase the chances of detecting use of a free'd name buffer if SAVENAME or SAVESTART wasn't passed in. Curiously, running with these changes doesn't panic the kernel, and should.
2002-07-24 15:42:22 +00:00
} else
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
cnp->cn_flags |= HASBUF;
Make our v_usecount vnode reference count work identically to the original BSD code. The association between the vnode and the vm_object no longer includes reference counts. The major difference is that vm_object's are no longer freed gratuitiously from the vnode, and so once an object is created for the vnode, it will last as long as the vnode does. When a vnode object reference count is incremented, then the underlying vnode reference count is incremented also. The two "objects" are now more intimately related, and so the interactions are now much less complex. When vnodes are now normally placed onto the free queue with an object still attached. The rundown of the object happens at vnode rundown time, and happens with exactly the same filesystem semantics of the original VFS code. There is absolutely no need for vnode_pager_uncache and other travesties like that anymore. A side-effect of these changes is that SMP locking should be much simpler, the I/O copyin/copyout optimizations work, NFS should be more ponderable, and further work on layered filesystems should be less frustrating, because of the totally coherent management of the vnode objects and vnodes. Please be careful with your system while running this code, but I would greatly appreciate feedback as soon a reasonably possible.
1998-01-06 05:26:17 +00:00
save some bytes by using more concise SDT_PROBE<n> instead of SDT_PROBE SDT_PROBE requires 5 parameters whereas SDT_PROBE<n> requires n parameters where n is typically smaller than 5. Perhaps SDT_PROBE should be made a private implementation detail. MFC after: 20 days
2015-09-28 12:14:16 +00:00
SDT_PROBE2(vfs, namei, lookup, return, 0, ndp->ni_vp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (0);
}
if (ndp->ni_loopcnt++ >= MAXSYMLINKS) {
error = ELOOP;
break;
}
Introduce support for Mandatory Access Control and extensible kernel access control. Authorize vop_readlink() and vop_lookup() activities during recursive path lookup via namei() via calls to appropriate MAC entry points. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-01 01:21:40 +00:00
#ifdef MAC
Add a new 'NOMACCHECK' flag to namei() NDINIT flags, which permits the caller to indicate that MAC checks are not required for the lookup. Similar to IO_NOMACCHECK for vn_rdwr(), this indicates that the caller has already performed all required protections and that this is an internally generated operation. This will be used by the NFS server code, as we don't currently enforce MAC protections against requests delivered via NFS. While here, add NOCROSSMOUNT to PARAMASK; apparently this was used at one point for name lookup flag checking, but isn't any longer or it would have triggered from the NFS server code passing it to indicate that mountpoints shouldn't be crossed in lookups. Approved by: re Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-19 21:25:51 +00:00
if ((cnp->cn_flags & NOMACCHECK) == 0) {
Merge first in a series of TrustedBSD MAC Framework KPI changes from Mac OS X Leopard--rationalize naming for entry points to the following general forms: mac_<object>_<method/action> mac_<object>_check_<method/action> The previous naming scheme was inconsistent and mostly reversed from the new scheme. Also, make object types more consistent and remove spaces from object types that contain multiple parts ("posix_sem" -> "posixsem") to make mechanical parsing easier. Introduce a new "netinet" object type for certain IPv4/IPv6-related methods. Also simplify, slightly, some entry point names. All MAC policy modules will need to be recompiled, and modules not updates as part of this commit will need to be modified to conform to the new KPI. Sponsored by: SPARTA (original patches against Mac OS X) Obtained from: TrustedBSD Project, Apple Computer
2007-10-24 19:04:04 +00:00
error = mac_vnode_check_readlink(td->td_ucred,
Add a new 'NOMACCHECK' flag to namei() NDINIT flags, which permits the caller to indicate that MAC checks are not required for the lookup. Similar to IO_NOMACCHECK for vn_rdwr(), this indicates that the caller has already performed all required protections and that this is an internally generated operation. This will be used by the NFS server code, as we don't currently enforce MAC protections against requests delivered via NFS. While here, add NOCROSSMOUNT to PARAMASK; apparently this was used at one point for name lookup flag checking, but isn't any longer or it would have triggered from the NFS server code passing it to indicate that mountpoints shouldn't be crossed in lookups. Approved by: re Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-19 21:25:51 +00:00
ndp->ni_vp);
vfs: cosmetic changes to namei and namei_handle_root - don't initialize cnp during declaration - don't test error/!error, compare to 0 instead
2015-07-09 17:17:26 +00:00
if (error != 0)
Add a new 'NOMACCHECK' flag to namei() NDINIT flags, which permits the caller to indicate that MAC checks are not required for the lookup. Similar to IO_NOMACCHECK for vn_rdwr(), this indicates that the caller has already performed all required protections and that this is an internally generated operation. This will be used by the NFS server code, as we don't currently enforce MAC protections against requests delivered via NFS. While here, add NOCROSSMOUNT to PARAMASK; apparently this was used at one point for name lookup flag checking, but isn't any longer or it would have triggered from the NFS server code passing it to indicate that mountpoints shouldn't be crossed in lookups. Approved by: re Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-19 21:25:51 +00:00
break;
}
Introduce support for Mandatory Access Control and extensible kernel access control. Authorize vop_readlink() and vop_lookup() activities during recursive path lookup via namei() via calls to appropriate MAC entry points. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-01 01:21:40 +00:00
#endif
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (ndp->ni_pathlen > 1)
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
cp = uma_zalloc(namei_zone, M_WAITOK);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
else
cp = cnp->cn_pnbuf;
aiov.iov_base = cp;
aiov.iov_len = MAXPATHLEN;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = 0;
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_SYSSPACE;
Further refine the handling of stop signals in the NFS client. The changes in r246417 were incomplete as they did not add explicit calls to sigdeferstop() around all the places that previously passed SBDRY to _sleep(). In addition, nfs_getcacheblk() could trigger a write RPC from getblk() resulting in sigdeferstop() recursing. Rather than manually deferring stop signals in specific places, change the VFS_*() and VOP_*() methods to defer stop signals for filesystems which request this behavior via a new VFCF_SBDRY flag. Note that this has to be a VFC flag rather than a MNTK flag so that it works properly with VFS_MOUNT() when the mount is not yet fully constructed. For now, only the NFS clients are set this new flag in VFS_SET(). A few other related changes: - Add an assertion to ensure that TDF_SBDRY doesn't leak to userland. - When a lookup request uses VOP_READLINK() to follow a symlink, mark the request as being on behalf of the thread performing the lookup (cnp_thread) rather than using a NULL thread pointer. This causes NFS to properly handle signals during this VOP on an interruptible mount. PR: kern/176179 Reported by: Russell Cattelan (sigdeferstop() recursion) Reviewed by: kib MFC after: 1 month
2013-02-21 19:02:50 +00:00
auio.uio_td = td;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
auio.uio_resid = MAXPATHLEN;
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred);
vfs: cosmetic changes to namei and namei_handle_root - don't initialize cnp during declaration - don't test error/!error, compare to 0 instead
2015-07-09 17:17:26 +00:00
if (error != 0) {
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (ndp->ni_pathlen > 1)
Remove references to vm_zone.h and switch over to the new uma API. Also, remove maxsockets. If you look carefully you'll notice that the old zone allocator never honored this anyway.
2002-03-20 04:09:59 +00:00
uma_zfree(namei_zone, cp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
break;
}
linklen = MAXPATHLEN - auio.uio_resid;
After exhaustive discussions and some meandering and confusion, enough people are on track with the cause and effect of this, and although fixing this severely degenerate case appears to violate the letter of POSIX.1-200x, Bruce and I (and enough others) agree that it should be comitted. So, this patch generates an ENOENT error for any attempt to do a path lookup through an empty symlink (e.g. open(), stat()). Submitted by: "Andrey A. Chernov" <ache@nagual.pp.ru> Reviewed by: bde Discussed exhaustively on: freebsd-current Previously committed to: NetBSD 4 years ago
2001-06-24 05:24:41 +00:00
if (linklen == 0) {
if (ndp->ni_pathlen > 1)
Remove references to vm_zone.h and switch over to the new uma API. Also, remove maxsockets. If you look carefully you'll notice that the old zone allocator never honored this anyway.
2002-03-20 04:09:59 +00:00
uma_zfree(namei_zone, cp);
After exhaustive discussions and some meandering and confusion, enough people are on track with the cause and effect of this, and although fixing this severely degenerate case appears to violate the letter of POSIX.1-200x, Bruce and I (and enough others) agree that it should be comitted. So, this patch generates an ENOENT error for any attempt to do a path lookup through an empty symlink (e.g. open(), stat()). Submitted by: "Andrey A. Chernov" <ache@nagual.pp.ru> Reviewed by: bde Discussed exhaustively on: freebsd-current Previously committed to: NetBSD 4 years ago
2001-06-24 05:24:41 +00:00
error = ENOENT;
break;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (linklen + ndp->ni_pathlen >= MAXPATHLEN) {
if (ndp->ni_pathlen > 1)
Remove references to vm_zone.h and switch over to the new uma API. Also, remove maxsockets. If you look carefully you'll notice that the old zone allocator never honored this anyway.
2002-03-20 04:09:59 +00:00
uma_zfree(namei_zone, cp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
error = ENAMETOOLONG;
break;
}
if (ndp->ni_pathlen > 1) {
bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen);
Remove references to vm_zone.h and switch over to the new uma API. Also, remove maxsockets. If you look carefully you'll notice that the old zone allocator never honored this anyway.
2002-03-20 04:09:59 +00:00
uma_zfree(namei_zone, cnp->cn_pnbuf);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
cnp->cn_pnbuf = cp;
} else
cnp->cn_pnbuf[linklen] = '\0';
ndp->ni_pathlen += linklen;
vput(ndp->ni_vp);
dp = ndp->ni_dvp;
vfs: avoid spurious vref/vrele for absolute lookups namei used to vref fd_cdir, which was immediatley vrele'd on entry to the loop. Check for absolute lookup and vref the right vnode the first time. Reviewed by: kib
2015-07-09 15:06:58 +00:00
/*
* Check if root directory should replace current directory.
*/
cnp->cn_nameptr = cnp->cn_pnbuf;
if (*(cnp->cn_nameptr) == '/') {
vrele(dp);
error = namei_handle_root(ndp, &dp);
vfs: provide a common exit point in namei for error cases This shortens the function, adds the SDT_PROBE use for error cases and consistenly unrefs rootdir last. Reviewed by: kib MFC after: 2 weeks
2016-08-27 22:43:41 +00:00
if (error != 0)
goto out;
vfs: avoid spurious vref/vrele for absolute lookups namei used to vref fd_cdir, which was immediatley vrele'd on entry to the loop. Check for absolute lookup and vref the right vnode the first time. Reviewed by: kib
2015-07-09 15:06:58 +00:00
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
vput(ndp->ni_vp);
ndp->ni_vp = NULL;
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
vrele(ndp->ni_dvp);
vfs: provide a common exit point in namei for error cases This shortens the function, adds the SDT_PROBE use for error cases and consistenly unrefs rootdir last. Reviewed by: kib MFC after: 2 weeks
2016-08-27 22:43:41 +00:00
out:
vrele(ndp->ni_rootdir);
namei_cleanup_cnp(cnp);
save some bytes by using more concise SDT_PROBE<n> instead of SDT_PROBE SDT_PROBE requires 5 parameters whereas SDT_PROBE<n> requires n parameters where n is typically smaller than 5. Perhaps SDT_PROBE should be made a private implementation detail. MFC after: 20 days
2015-09-28 12:14:16 +00:00
SDT_PROBE2(vfs, namei, lookup, return, error, NULL);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (error);
}
Fixes up the handling of shared vnode lock lookups in the NFS client, adds a FS type specific flag indicating that the FS supports shared vnode lock lookups, adds some logic in vfs_lookup.c to test this flag and set lock flags appropriately. - amd on 6.x is a non-starter (without this change). Using amd under heavy load results in a deadlock (with cascading vnode locks all the way to the root) very quickly. - This change should also fix the more general problem of cascading vnode deadlocks when an NFS server goes down. Ideally, we wouldn't need these changes, as enabling shared vnode lock lookups globally would work. Unfortunately, UFS, for example isn't ready for shared vnode lock lookups, crashing pretty quickly. This change is the result of discussions with Stephan Uphoff (ups@). Reviewed by: ups@
2006-09-13 18:39:09 +00:00
static int
Add MNTK_LOOKUP_EXCL_DOTDOT struct mount flag, which specifies to the lookup code that dotdot lookups shall override any shared lock requests with the exclusive one. The flag is useful for filesystems which sometimes need to upgrade shared lock to exclusive inside the VOP_LOOKUP or later, which cannot be done safely for dotdot, due to dvp also locked and causing LOR. In collaboration with: pho MFC after: 3 weeks
2012-09-09 19:11:52 +00:00
compute_cn_lkflags(struct mount *mp, int lkflags, int cnflags)
Fixes up the handling of shared vnode lock lookups in the NFS client, adds a FS type specific flag indicating that the FS supports shared vnode lock lookups, adds some logic in vfs_lookup.c to test this flag and set lock flags appropriately. - amd on 6.x is a non-starter (without this change). Using amd under heavy load results in a deadlock (with cascading vnode locks all the way to the root) very quickly. - This change should also fix the more general problem of cascading vnode deadlocks when an NFS server goes down. Ideally, we wouldn't need these changes, as enabling shared vnode lock lookups globally would work. Unfortunately, UFS, for example isn't ready for shared vnode lock lookups, crashing pretty quickly. This change is the result of discussions with Stephan Uphoff (ups@). Reviewed by: ups@
2006-09-13 18:39:09 +00:00
{
A few style nits.
2008-11-03 19:33:20 +00:00
Add MNTK_LOOKUP_EXCL_DOTDOT struct mount flag, which specifies to the lookup code that dotdot lookups shall override any shared lock requests with the exclusive one. The flag is useful for filesystems which sometimes need to upgrade shared lock to exclusive inside the VOP_LOOKUP or later, which cannot be done safely for dotdot, due to dvp also locked and causing LOR. In collaboration with: pho MFC after: 3 weeks
2012-09-09 19:11:52 +00:00
if (mp == NULL || ((lkflags & LK_SHARED) &&
(!(mp->mnt_kern_flag & MNTK_LOOKUP_SHARED) ||
((cnflags & ISDOTDOT) &&
(mp->mnt_kern_flag & MNTK_LOOKUP_EXCL_DOTDOT))))) {
Fixes up the handling of shared vnode lock lookups in the NFS client, adds a FS type specific flag indicating that the FS supports shared vnode lock lookups, adds some logic in vfs_lookup.c to test this flag and set lock flags appropriately. - amd on 6.x is a non-starter (without this change). Using amd under heavy load results in a deadlock (with cascading vnode locks all the way to the root) very quickly. - This change should also fix the more general problem of cascading vnode deadlocks when an NFS server goes down. Ideally, we wouldn't need these changes, as enabling shared vnode lock lookups globally would work. Unfortunately, UFS, for example isn't ready for shared vnode lock lookups, crashing pretty quickly. This change is the result of discussions with Stephan Uphoff (ups@). Reviewed by: ups@
2006-09-13 18:39:09 +00:00
lkflags &= ~LK_SHARED;
lkflags |= LK_EXCLUSIVE;
}
Fix two issues with lockmgr(9) LK_CAN_SHARE() test, which determines whether the shared request for already shared-locked lock could be granted. Both problems result in the exclusive locker starvation. The concurrent exclusive request is indicated by either LK_EXCLUSIVE_WAITERS or LK_EXCLUSIVE_SPINNERS flags. The reverse condition, i.e. no exclusive waiters, must check that both flags are cleared. Add a flag LK_NODDLKTREAT for shared lock request to indicate that current thread guarantees that it does not own the lock in shared mode. This turns back the exclusive lock starvation avoidance code; see man page update for detailed description. Use LK_NODDLKTREAT when doing lookup(9). Reported and tested by: pho No objections from: attilio Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2014-11-02 13:10:31 +00:00
lkflags |= LK_NODDLKTREAT;
A few style nits.
2008-11-03 19:33:20 +00:00
return (lkflags);
Fixes up the handling of shared vnode lock lookups in the NFS client, adds a FS type specific flag indicating that the FS supports shared vnode lock lookups, adds some logic in vfs_lookup.c to test this flag and set lock flags appropriately. - amd on 6.x is a non-starter (without this change). Using amd under heavy load results in a deadlock (with cascading vnode locks all the way to the root) very quickly. - This change should also fix the more general problem of cascading vnode deadlocks when an NFS server goes down. Ideally, we wouldn't need these changes, as enabling shared vnode lock lookups globally would work. Unfortunately, UFS, for example isn't ready for shared vnode lock lookups, crashing pretty quickly. This change is the result of discussions with Stephan Uphoff (ups@). Reviewed by: ups@
2006-09-13 18:39:09 +00:00
}
Add a new internal mount flag (MNTK_EXTENDED_SHARED) to indicate that a filesystem supports additional operations using shared vnode locks. Currently this is used to enable shared locks for open() and close() of read-only file descriptors. - When an ISOPEN namei() request is performed with LOCKSHARED, use a shared vnode lock for the leaf vnode only if the mount point has the extended shared flag set. - Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but not O_CREAT. - Use a shared vnode lock around VOP_CLOSE() if the file was opened with O_RDONLY and the mountpoint has the extended shared flag set. - Adjust md(4) to upgrade the vnode lock on the vnode it gets back from vn_open() since it now may only have a shared vnode lock. - Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since FIFO's require exclusive vnode locks for their open() and close() routines. (My recent MPSAFE patches for UDF and cd9660 already included this change.) - Enable extended shared operations on UFS, cd9660, and UDF. Submitted by: ups Reviewed by: pjd (ZFS bits) MFC after: 1 month
2009-03-11 14:13:47 +00:00
static __inline int
needs_exclusive_leaf(struct mount *mp, int flags)
{
/*
* Intermediate nodes can use shared locks, we only need to
* force an exclusive lock for leaf nodes.
*/
if ((flags & (ISLASTCN | LOCKLEAF)) != (ISLASTCN | LOCKLEAF))
return (0);
/* Always use exclusive locks if LOCKSHARED isn't set. */
if (!(flags & LOCKSHARED))
return (1);
/*
* For lookups during open(), if the mount point supports
* extended shared operations, then use a shared lock for the
* leaf node, otherwise use an exclusive lock.
*/
Both vn_close() and VFS_PROLOGUE() evaluate vp->v_mount twice, without holding the vnode lock; vp->v_mount is checked first for NULL equiality, and then dereferenced if not NULL. If vnode is reclaimed meantime, second dereference would still give NULL. Change VFS_PROLOGUE() to evaluate the mp once, convert MNTK_SHARED_WRITES and MNTK_EXTENDED_SHARED tests into inline functions. Reviewed by: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2013-11-09 20:30:13 +00:00
if ((flags & ISOPEN) != 0)
return (!MNT_EXTENDED_SHARED(mp));
Add a new internal mount flag (MNTK_EXTENDED_SHARED) to indicate that a filesystem supports additional operations using shared vnode locks. Currently this is used to enable shared locks for open() and close() of read-only file descriptors. - When an ISOPEN namei() request is performed with LOCKSHARED, use a shared vnode lock for the leaf vnode only if the mount point has the extended shared flag set. - Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but not O_CREAT. - Use a shared vnode lock around VOP_CLOSE() if the file was opened with O_RDONLY and the mountpoint has the extended shared flag set. - Adjust md(4) to upgrade the vnode lock on the vnode it gets back from vn_open() since it now may only have a shared vnode lock. - Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since FIFO's require exclusive vnode locks for their open() and close() routines. (My recent MPSAFE patches for UDF and cd9660 already included this change.) - Enable extended shared operations on UFS, cd9660, and UDF. Submitted by: ups Reviewed by: pjd (ZFS bits) MFC after: 1 month
2009-03-11 14:13:47 +00:00
/*
* Lookup requests outside of open() that specify LOCKSHARED
* only need a shared lock on the leaf vnode.
*/
Gah, fix the code to match the comment. For non-open lookups use a shared vnode lock for the leaf vnode if LOCKSHARED is set. Submitted by: rdivacky
2009-03-11 14:39:55 +00:00
return (0);
Add a new internal mount flag (MNTK_EXTENDED_SHARED) to indicate that a filesystem supports additional operations using shared vnode locks. Currently this is used to enable shared locks for open() and close() of read-only file descriptors. - When an ISOPEN namei() request is performed with LOCKSHARED, use a shared vnode lock for the leaf vnode only if the mount point has the extended shared flag set. - Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but not O_CREAT. - Use a shared vnode lock around VOP_CLOSE() if the file was opened with O_RDONLY and the mountpoint has the extended shared flag set. - Adjust md(4) to upgrade the vnode lock on the vnode it gets back from vn_open() since it now may only have a shared vnode lock. - Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since FIFO's require exclusive vnode locks for their open() and close() routines. (My recent MPSAFE patches for UDF and cd9660 already included this change.) - Enable extended shared operations on UFS, cd9660, and UDF. Submitted by: ups Reviewed by: pjd (ZFS bits) MFC after: 1 month
2009-03-11 14:13:47 +00:00
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
* Search a pathname.
* This is a very central and rather complicated routine.
*
* The pathname is pointed to by ni_ptr and is of length ni_pathlen.
* The starting directory is taken from ni_startdir. The pathname is
* descended until done, or a symbolic link is encountered. The variable
* ni_more is clear if the path is completed; it is set to one if a
* symbolic link needing interpretation is encountered.
*
* The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
* whether the name is to be looked up, created, renamed, or deleted.
* When CREATE, RENAME, or DELETE is specified, information usable in
* creating, renaming, or deleting a directory entry may be calculated.
* If flag has LOCKPARENT or'ed into it, the parent directory is returned
* locked. If flag has WANTPARENT or'ed into it, the parent directory is
* returned unlocked. Otherwise the parent directory is not returned. If
* the target of the pathname exists and LOCKLEAF is or'ed into the flag
* the target is returned locked, otherwise it is returned unlocked.
* When creating or renaming and LOCKPARENT is specified, the target may not
* be ".". When deleting and LOCKPARENT is specified, the target may be ".".
Remove trailing whitespace.
1995-05-30 08:16:23 +00:00
*
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* Overall outline of lookup:
*
* dirloop:
* identify next component of name at ndp->ni_ptr
* handle degenerate case where name is null string
* if .. and crossing mount points and on mounted filesys, find parent
* call VOP_LOOKUP routine for next component name
* directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set
* component vnode returned in ni_vp (if it exists), locked.
* if result vnode is mounted on and crossing mount points,
* find mounted on vnode
* if more components of name, do next level at dirloop
* return the answer in ni_vp, locked if LOCKLEAF set
* if LOCKPARENT set, return locked parent in ni_dvp
* if WANTPARENT set, return unlocked parent in ni_dvp
*/
int
Remove register, use ANSI function headers.
2006-08-05 21:40:59 +00:00
lookup(struct nameidata *ndp)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Remove register, use ANSI function headers.
2006-08-05 21:40:59 +00:00
char *cp; /* pointer into pathname argument */
kern: for pointers replace 0 with NULL. These are mostly cosmetical, no functional change. Found with devel/coccinelle.
2016-04-15 16:10:11 +00:00
struct vnode *dp = NULL; /* the directory we are searching */
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
struct vnode *tdp; /* saved dp */
struct mount *mp; /* mount table entry */
Add hierarchical jails. A jail may further virtualize its environment by creating a child jail, which is visible to that jail and to any parent jails. Child jails may be restricted more than their parents, but never less. Jail names reflect this hierarchy, being MIB-style dot-separated strings. Every thread now points to a jail, the default being prison0, which contains information about the physical system. Prison0's root directory is the same as rootvnode; its hostname is the same as the global hostname, and its securelevel replaces the global securelevel. Note that the variable "securelevel" has actually gone away, which should not cause any problems for code that properly uses securelevel_gt() and securelevel_ge(). Some jail-related permissions that were kept in global variables and set via sysctls are now per-jail settings. The sysctls still exist for backward compatibility, used only by the now-deprecated jail(2) system call. Approved by: bz (mentor)
2009-05-27 14:11:23 +00:00
struct prison *pr;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
int docache; /* == 0 do not cache last component */
int wantparent; /* 1 => wantparent or lockparent flag */
int rdonly; /* lookup read-only flag bit */
int error = 0;
Unlock current directory when calling VFS_ROOT() because underlying filesystem may hold the lock. Otherwise unavoidable deadlock will occur. This shouldn't have any side effects as long as we hold vfs lock. Obtained from: NetBSD
2000-09-13 08:57:56 +00:00
int dpunlocked = 0; /* dp has already been unlocked */
Fix autofs triggering problem. Assume you have an NFS server, 192.168.1.1, with share "share". This commit fixes a problem where "mkdir /net/192.168.1.1/share/meh" would return spurious error instead of creating the directory if the target filesystem wasn't mounted yet; subsequent attempts would work correctly. The failure scenario is kind of complicated to explain, but it all boils down to calling VOP_MKDIR() for the target filesystem (NFS) with wrong dvp - the autofs vnode instead of the filesystem root mounted over it. Reviewed by: kib@ MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D5442
2016-03-12 07:54:42 +00:00
int relookup = 0; /* do not consume the path component */
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
struct componentname *cnp = &ndp->ni_cnd;
Fixes up the handling of shared vnode lock lookups in the NFS client, adds a FS type specific flag indicating that the FS supports shared vnode lock lookups, adds some logic in vfs_lookup.c to test this flag and set lock flags appropriately. - amd on 6.x is a non-starter (without this change). Using amd under heavy load results in a deadlock (with cascading vnode locks all the way to the root) very quickly. - This change should also fix the more general problem of cascading vnode deadlocks when an NFS server goes down. Ideally, we wouldn't need these changes, as enabling shared vnode lock lookups globally would work. Unfortunately, UFS, for example isn't ready for shared vnode lock lookups, crashing pretty quickly. This change is the result of discussions with Stephan Uphoff (ups@). Reviewed by: ups@
2006-09-13 18:39:09 +00:00
int lkflags_save;
Avoid double-unlock or double unreference for ndp->ni_dvp when the vnode dp lock upgrade right after the 'success' label fails. In collaboration with: pho MFC after: 1 week
2012-01-01 18:45:59 +00:00
int ni_dvp_unlocked;
Fixes up the handling of shared vnode lock lookups in the NFS client, adds a FS type specific flag indicating that the FS supports shared vnode lock lookups, adds some logic in vfs_lookup.c to test this flag and set lock flags appropriately. - amd on 6.x is a non-starter (without this change). Using amd under heavy load results in a deadlock (with cascading vnode locks all the way to the root) very quickly. - This change should also fix the more general problem of cascading vnode deadlocks when an NFS server goes down. Ideally, we wouldn't need these changes, as enabling shared vnode lock lookups globally would work. Unfortunately, UFS, for example isn't ready for shared vnode lock lookups, crashing pretty quickly. This change is the result of discussions with Stephan Uphoff (ups@). Reviewed by: ups@
2006-09-13 18:39:09 +00:00
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
* Setup: break out flag bits into variables.
*/
Avoid double-unlock or double unreference for ndp->ni_dvp when the vnode dp lock upgrade right after the 'success' label fails. In collaboration with: pho MFC after: 1 week
2012-01-01 18:45:59 +00:00
ni_dvp_unlocked = 0;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT);
- Remove an unused variable from relookup(). - Assert that REMOVE, CREATE, and RENAME callers have WANTPARENT or LOCKPARENT set. You can't complete any of these operations without at least a reference to the parent. Many filesystems check for this case even though it isn't possible in the current system.
2005-03-28 13:56:56 +00:00
KASSERT(cnp->cn_nameiop == LOOKUP || wantparent,
("CREATE, DELETE, RENAME require LOCKPARENT or WANTPARENT."));
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE;
if (cnp->cn_nameiop == DELETE ||
Fixed namei caching for LOOKUPs. It was broken for lstat() and olstat(). Successful lstat()s purged an existing entry as well as not caching the result. This bug was introduced in Lite1 by setting the LOCKPARENT flag for [o]lstat() in order to support the inherit-attributes-from-parent- directory misfeature for symlinks. LOCKPARENT was previously only set for CREATEs and DELETEs. It is now set for LOOKUPs, but only for [o]lstat(), so the problem wasn't very noticeable.
1997-02-18 06:46:41 +00:00
(wantparent && cnp->cn_nameiop != CREATE &&
cnp->cn_nameiop != LOOKUP))
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
docache = 0;
rdonly = cnp->cn_flags & RDONLY;
cnp->cn_flags &= ~ISSYMLINK;
- Set cn_lkflags to LK_SHARED in the LOOKUP_SHARED case so that we only acquire shared locks on intermediate directories. - For the LASTCN, we may have to LK_UPGRADE the parent directory before we lookup the last component. - Acquire VFS_ROOT and dp locks based on the cn_lkflag. Sponsored by: Isilon Systems, Inc.
2005-03-29 10:07:15 +00:00
ndp->ni_dvp = NULL;
/*
* We use shared locks until we hit the parent of the last cn then
* we adjust based on the requesting flags.
*/
- Include opt_vfs.h for LOOKUP_SHARED. - Control the behavior of shared lookups with the lookup_shared sysctl which has its default behavior set via the LOOKUP_SHARED option.
2005-04-03 23:50:20 +00:00
if (lookup_shared)
cnp->cn_lkflags = LK_SHARED;
else
cnp->cn_lkflags = LK_EXCLUSIVE;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
dp = ndp->ni_startdir;
ndp->ni_startdir = NULLVP;
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
vn_lock(dp,
Add MNTK_LOOKUP_EXCL_DOTDOT struct mount flag, which specifies to the lookup code that dotdot lookups shall override any shared lock requests with the exclusive one. The flag is useful for filesystems which sometimes need to upgrade shared lock to exclusive inside the VOP_LOOKUP or later, which cannot be done safely for dotdot, due to dvp also locked and causing LOR. In collaboration with: pho MFC after: 3 weeks
2012-09-09 19:11:52 +00:00
compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY,
cnp->cn_flags));
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
dirloop:
/*
* Search a new directory.
*
* The last component of the filename is left accessible via
* cnp->cn_nameptr for callers that need the name. Callers needing
* the name set the SAVENAME flag. When done, they assume
* responsibility for freeing the pathname buffer.
*/
for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++)
Before we start to mess with the VFS name-cache clean things up a little bit: Isolate the namecache in its own file, and give it a dedicated malloc type.
1999-10-03 12:18:29 +00:00
continue;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
cnp->cn_namelen = cp - cnp->cn_nameptr;
if (cnp->cn_namelen > NAME_MAX) {
error = ENAMETOOLONG;
goto bad;
}
#ifdef NAMEI_DIAGNOSTIC
{ char c = *cp;
*cp = '\0';
printf("{%s}: ", cnp->cn_nameptr);
*cp = c; }
#endif
ndp->ni_pathlen -= cnp->cn_namelen;
ndp->ni_next = cp;
Ignore trailing slashes in pathnames that "refer to a directory", as is required to be POSIXLY_CORRECT and "right". I interpret "referring to a directory" as being a directory or becoming a directory. E.g., the trailing slashes in mkdir("/nonesuch/"), rename("/tmp", /nonesuch/") and link("/tmp", "/root_can_like_dirs/") are ignored because the target will become a directory if the syscall succeeds. A trailing slash on a symlink causes the symlink to be followed (this is a bug if the symlink doesn't point to a directory; fix later).
1995-07-31 00:35:58 +00:00
/*
* Replace multiple slashes by a single slash and trailing slashes
* by a null. This must be done before VOP_LOOKUP() because some
* fs's don't know about trailing slashes. Remember if there were
* trailing slashes to handle symlinks, existing non-directories
* and non-existing files that won't be directories specially later.
*/
while (*cp == '/' && (cp[1] == '/' || cp[1] == '\0')) {
cp++;
ndp->ni_pathlen--;
if (*cp == '\0') {
Eliminate trailing_slash, which was made redundant in r193028. Remove a couple of 4-year-old "temporary" KASSERTs. Improve comments. MFC after: 1 week
2009-06-06 00:49:49 +00:00
*ndp->ni_next = '\0';
Let vfs_lookup() return ENOTDIR if the path has a trailing slash and the last component is a symlink to something that isn't a directory. We introduce a new namei flag, TRAILINGSLASH, which is set by lookup() if the last component is followed by a slash. The trailing slash is then stripped, as before. If the final component is a symlink, lookup() will return to namei(), which will expand the symlink and call lookup() with the new path. When all symlinks have been resolved, lookup() checks if the TRAILINGSLASH flag is set, and if it is, and the vnode it ended up with is not a directory, it returns ENOTDIR. PR: kern/21768 Submitted by: Eygene Ryabinkin <rea-fbsd@codelabs.ru> MFC after: 3 weeks
2009-05-29 10:02:44 +00:00
cnp->cn_flags |= TRAILINGSLASH;
Ignore trailing slashes in pathnames that "refer to a directory", as is required to be POSIXLY_CORRECT and "right". I interpret "referring to a directory" as being a directory or becoming a directory. E.g., the trailing slashes in mkdir("/nonesuch/"), rename("/tmp", /nonesuch/") and link("/tmp", "/root_can_like_dirs/") are ignored because the target will become a directory if the syscall succeeds. A trailing slash on a symlink causes the symlink to be followed (this is a bug if the symlink doesn't point to a directory; fix later).
1995-07-31 00:35:58 +00:00
}
}
ndp->ni_next = cp;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
cnp->cn_flags |= MAKEENTRY;
if (*cp == '\0' && docache == 0)
cnp->cn_flags &= ~MAKEENTRY;
if (cnp->cn_namelen == 2 &&
cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.')
cnp->cn_flags |= ISDOTDOT;
else
cnp->cn_flags &= ~ISDOTDOT;
if (*ndp->ni_next == 0)
cnp->cn_flags |= ISLASTCN;
else
cnp->cn_flags &= ~ISLASTCN;
When rename("a", "b/.") is performed, target namei() call returns dvp == vp. Rename syscall does not check for the case, and at least ufs_rename() cannot deal with it. POSIX explicitely requires that both rename(2) and rmdir(2) return EINVAL when any of the pathes end in "/.". Detect the slashdot lookup for RENAME or REMOVE in lookup(), and return EINVAL. Reported by: Jim Meyering <jim meyering net> Tested by: simon, pho MFC after: 1 week
2009-11-10 11:50:37 +00:00
if ((cnp->cn_flags & ISLASTCN) != 0 &&
cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.' &&
(cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
error = EINVAL;
goto bad;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
* Check for degenerate name (e.g. / or "")
* which is a way of talking about a directory,
* e.g. like "/." or ".".
*/
if (cnp->cn_nameptr[0] == '\0') {
if (dp->v_type != VDIR) {
error = ENOTDIR;
goto bad;
}
This is the kernel Lite/2 commit. There are some requisite userland changes, so don't expect to be able to run the kernel as-is (very well) without the appropriate Lite/2 userland changes. The system boots and can mount UFS filesystems. Untested: ext2fs, msdosfs, NFS Known problems: Incorrect Berkeley ID strings in some files. Mount_std mounts will not work until the getfsent library routine is changed. Reviewed by: various people Submitted by: Jeffery Hsu <hsu@freebsd.org>
1997-02-10 02:22:35 +00:00
if (cnp->cn_nameiop != LOOKUP) {
error = EISDIR;
goto bad;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (wantparent) {
ndp->ni_dvp = dp;
VREF(dp);
}
ndp->ni_vp = dp;
Add AUDITVNODE[12] flags to namei(), which cause namei() to audit path and vnode attribute information for looked up vnodes during the lookup operation. This will allow consumers of namei() to specify that this information be added to the in-process audit record. Submitted by: wsalamon Obtained from: TrustedBSD Project
2006-02-05 15:42:01 +00:00
if (cnp->cn_flags & AUDITVNODE1)
Rework vnode argument auditing to follow the same structure, in order to avoid exposing ARG_ macros/flag values outside of the audit code in order to name which one of two possible vnodes will be audited for a system call. Approved by: re (kib) Obtained from: TrustedBSD Project MFC after: 1 month
2009-07-28 21:52:24 +00:00
AUDIT_ARG_VNODE1(dp);
Add AUDITVNODE[12] flags to namei(), which cause namei() to audit path and vnode attribute information for looked up vnodes during the lookup operation. This will allow consumers of namei() to specify that this information be added to the in-process audit record. Submitted by: wsalamon Obtained from: TrustedBSD Project
2006-02-05 15:42:01 +00:00
else if (cnp->cn_flags & AUDITVNODE2)
Rework vnode argument auditing to follow the same structure, in order to avoid exposing ARG_ macros/flag values outside of the audit code in order to name which one of two possible vnodes will be audited for a system call. Approved by: re (kib) Obtained from: TrustedBSD Project MFC after: 1 month
2009-07-28 21:52:24 +00:00
AUDIT_ARG_VNODE2(dp);
Add AUDITVNODE[12] flags to namei(), which cause namei() to audit path and vnode attribute information for looked up vnodes during the lookup operation. This will allow consumers of namei() to specify that this information be added to the in-process audit record. Submitted by: wsalamon Obtained from: TrustedBSD Project
2006-02-05 15:42:01 +00:00
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (!(cnp->cn_flags & (LOCKPARENT | LOCKLEAF)))
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(dp, 0);
Introduce NDFREE (and remove VOP_ABORTOP)
1999-12-15 23:02:35 +00:00
/* XXX This should probably move to the top of function. */
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (cnp->cn_flags & SAVESTART)
panic("lookup: SAVESTART");
- Acquire and release Giant as we enter and leave filesystems which require it. - Track the status of Giant with the nd flag HASGIANT. - Release giant on return of namei() callers are not marked MPSAFE as they already own giant. Sponsored By: Isilon Systems, Inc.
2005-01-24 10:27:05 +00:00
goto success;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
/*
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
* Handle "..": five special cases.
* 0. If doing a capability lookup, return ENOTCAPABLE (this is a
* fairly conservative design choice, but it's the only one that we
* are satisfied guarantees the property we're looking for).
Return EPERM from lookup() if cn_nameiop is DELETE or RENAME and the last component of the path name is "..". This keeps VOP_LOOKUP() from locking vnodes in reverse order. Tested by: Denis Shaposhnikov <dsh AT vlink DOT ru> MFC after: 3 days
2006-01-21 19:57:56 +00:00
* 1. Return an error if this is the last component of
* the name and the operation is DELETE or RENAME.
* 2. If at root directory (e.g. after chroot)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* or at absolute root directory
* then ignore it so can't get out.
Return EPERM from lookup() if cn_nameiop is DELETE or RENAME and the last component of the path name is "..". This keeps VOP_LOOKUP() from locking vnodes in reverse order. Tested by: Denis Shaposhnikov <dsh AT vlink DOT ru> MFC after: 3 days
2006-01-21 19:57:56 +00:00
* 3. If this vnode is the root of a mounted
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* filesystem, then replace it with the
* vnode which was mounted on so we take the
More s/file system/filesystem/g
2002-05-16 21:28:32 +00:00
* .. in the other filesystem.
Return EPERM from lookup() if cn_nameiop is DELETE or RENAME and the last component of the path name is "..". This keeps VOP_LOOKUP() from locking vnodes in reverse order. Tested by: Denis Shaposhnikov <dsh AT vlink DOT ru> MFC after: 3 days
2006-01-21 19:57:56 +00:00
* 4. If the vnode is the top directory of
Fix a hole in jail(2). Noticed by: Alexander Bezroutchko <abb@zenon.net>
1999-09-25 14:14:21 +00:00
* the jail or chroot, don't let them out.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
if (cnp->cn_flags & ISDOTDOT) {
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
if (ndp->ni_strictrelative != 0) {
Revisit the capability failure trace points. The initial implementation only logged instances where an operation on a file descriptor required capabilities which the file descriptor did not have. By adding a type enum to struct ktr_cap_fail, we can catch other types of capability failures as well, such as disallowed system calls or attempts to wrap a file descriptor with more capabilities than it had to begin with.
2011-10-18 07:28:58 +00:00
#ifdef KTRACE
if (KTRPOINT(curthread, KTR_CAPFAIL))
Fix panic in ktrcapfail() when no capability rights are passed. While here, correct all consumers to pass NULL instead of 0 as we pass capability rights as pointers now, not uint64_t. Reported by: Daniel Peyrolon Tested by: Daniel Peyrolon Approved by: re (marius)
2013-09-18 19:26:08 +00:00
ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
Revisit the capability failure trace points. The initial implementation only logged instances where an operation on a file descriptor required capabilities which the file descriptor did not have. By adding a type enum to struct ktr_cap_fail, we can catch other types of capability failures as well, such as disallowed system calls or attempts to wrap a file descriptor with more capabilities than it had to begin with.
2011-10-18 07:28:58 +00:00
#endif
Allow Capsicum capabilities to delegate constrained access to file system subtrees to sandboxed processes. - Use of absolute paths and '..' are limited in capability mode. - Use of absolute paths and '..' are limited when looking up relative to a capability. - When a name lookup is performed, identify what operation is to be performed (such as CAP_MKDIR) as well as check for CAP_LOOKUP. With these constraints, openat() and friends are now safe in capability mode, and can then be used by code such as the capability-mode runtime linker. Approved by: re (bz), mentor (rwatson) Sponsored by: Google Inc
2011-08-13 09:21:16 +00:00
error = ENOTCAPABLE;
goto bad;
}
Return EPERM from lookup() if cn_nameiop is DELETE or RENAME and the last component of the path name is "..". This keeps VOP_LOOKUP() from locking vnodes in reverse order. Tested by: Denis Shaposhnikov <dsh AT vlink DOT ru> MFC after: 3 days
2006-01-21 19:57:56 +00:00
if ((cnp->cn_flags & ISLASTCN) != 0 &&
(cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
Tweak previous vfs_lookup.c commit to return an EINVAL error from lookup() instead of EPERM when a DELETE or RENAME operation is attempted on "..". In kern_unlink(), remap EINVAL errors returned from namei() to EPERM to match existing (and POSIX required) behaviour. Discussed with: bde MFC after: 3 days
2006-01-22 19:37:02 +00:00
error = EINVAL;
Return EPERM from lookup() if cn_nameiop is DELETE or RENAME and the last component of the path name is "..". This keeps VOP_LOOKUP() from locking vnodes in reverse order. Tested by: Denis Shaposhnikov <dsh AT vlink DOT ru> MFC after: 3 days
2006-01-21 19:57:56 +00:00
goto bad;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
for (;;) {
Add hierarchical jails. A jail may further virtualize its environment by creating a child jail, which is visible to that jail and to any parent jails. Child jails may be restricted more than their parents, but never less. Jail names reflect this hierarchy, being MIB-style dot-separated strings. Every thread now points to a jail, the default being prison0, which contains information about the physical system. Prison0's root directory is the same as rootvnode; its hostname is the same as the global hostname, and its securelevel replaces the global securelevel. Note that the variable "securelevel" has actually gone away, which should not cause any problems for code that properly uses securelevel_gt() and securelevel_ge(). Some jail-related permissions that were kept in global variables and set via sysctls are now per-jail settings. The sysctls still exist for backward compatibility, used only by the now-deprecated jail(2) system call. Approved by: bz (mentor)
2009-05-27 14:11:23 +00:00
for (pr = cnp->cn_cred->cr_prison; pr != NULL;
pr = pr->pr_parent)
if (dp == pr->pr_root)
break;
Fix a hole in jail(2). Noticed by: Alexander Bezroutchko <abb@zenon.net>
1999-09-25 14:14:21 +00:00
if (dp == ndp->ni_rootdir ||
dp == ndp->ni_topdir ||
If both ISDOTDOT and NOCROSSMOUNT are set then lookup() might breaks out of the special handling for ".." and perform an ISDOTDOT VOP_LOOKUP() for a filesystem root vnode. Handle this case inside lookup(). Submitted by: tegge PR: 92785 MFC after: 1 week
2007-02-15 09:53:49 +00:00
dp == rootvnode ||
Add hierarchical jails. A jail may further virtualize its environment by creating a child jail, which is visible to that jail and to any parent jails. Child jails may be restricted more than their parents, but never less. Jail names reflect this hierarchy, being MIB-style dot-separated strings. Every thread now points to a jail, the default being prison0, which contains information about the physical system. Prison0's root directory is the same as rootvnode; its hostname is the same as the global hostname, and its securelevel replaces the global securelevel. Note that the variable "securelevel" has actually gone away, which should not cause any problems for code that properly uses securelevel_gt() and securelevel_ge(). Some jail-related permissions that were kept in global variables and set via sysctls are now per-jail settings. The sysctls still exist for backward compatibility, used only by the now-deprecated jail(2) system call. Approved by: bz (mentor)
2009-05-27 14:11:23 +00:00
pr != NULL ||
If both ISDOTDOT and NOCROSSMOUNT are set then lookup() might breaks out of the special handling for ".." and perform an ISDOTDOT VOP_LOOKUP() for a filesystem root vnode. Handle this case inside lookup(). Submitted by: tegge PR: 92785 MFC after: 1 week
2007-02-15 09:53:49 +00:00
((dp->v_vflag & VV_ROOT) != 0 &&
(cnp->cn_flags & NOCROSSMOUNT) != 0)) {
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
ndp->ni_dvp = dp;
ndp->ni_vp = dp;
VREF(dp);
goto nextname;
}
If both ISDOTDOT and NOCROSSMOUNT are set then lookup() might breaks out of the special handling for ".." and perform an ISDOTDOT VOP_LOOKUP() for a filesystem root vnode. Handle this case inside lookup(). Submitted by: tegge PR: 92785 MFC after: 1 week
2007-02-15 09:53:49 +00:00
if ((dp->v_vflag & VV_ROOT) == 0)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
break;
- Don't check v_mount for NULL to determine if a vnode has been recycled. Use the more appropriate VI_DOOMED flag instead. Sponsored by: Isilon Systems, Inc. MFC After: 1 week
2006-02-06 10:15:27 +00:00
if (dp->v_iflag & VI_DOOMED) { /* forced unmount */
When a file lookup fails due to encountering a doomed vnode from a forced unmount, consistently return ENOENT rather than EBADF. Reviewed by: kib MFC after: 1 month
2009-03-24 18:16:42 +00:00
error = ENOENT;
This is a fix for a problem described in PR kern/19572. It was recently discussed at -hackers. The problem is a null-pointer dereference that happens in kern/vfs_lookup.c when accessing ".." with a v_mount entry for the current directory vnode of NULL. This happens when a volume is forcibly unmounted, and the vnode for a working directory in the mounted volume is cleared. PR: 23191 Submitted by: Thomas Moestl <tmoestl@gmx.net>
2000-11-30 20:04:44 +00:00
goto bad;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
tdp = dp;
dp = dp->v_mount->mnt_vnodecovered;
VREF(dp);
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
vput(tdp);
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
vn_lock(dp,
compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags |
Add MNTK_LOOKUP_EXCL_DOTDOT struct mount flag, which specifies to the lookup code that dotdot lookups shall override any shared lock requests with the exclusive one. The flag is useful for filesystems which sometimes need to upgrade shared lock to exclusive inside the VOP_LOOKUP or later, which cannot be done safely for dotdot, due to dvp also locked and causing LOR. In collaboration with: pho MFC after: 3 weeks
2012-09-09 19:11:52 +00:00
LK_RETRY, ISDOTDOT));
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
}
/*
* We now have a segment name to search for, and a directory to search.
*/
unionlookup:
Introduce support for Mandatory Access Control and extensible kernel access control. Authorize vop_readlink() and vop_lookup() activities during recursive path lookup via namei() via calls to appropriate MAC entry points. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-01 01:21:40 +00:00
#ifdef MAC
Add a new 'NOMACCHECK' flag to namei() NDINIT flags, which permits the caller to indicate that MAC checks are not required for the lookup. Similar to IO_NOMACCHECK for vn_rdwr(), this indicates that the caller has already performed all required protections and that this is an internally generated operation. This will be used by the NFS server code, as we don't currently enforce MAC protections against requests delivered via NFS. While here, add NOCROSSMOUNT to PARAMASK; apparently this was used at one point for name lookup flag checking, but isn't any longer or it would have triggered from the NFS server code passing it to indicate that mountpoints shouldn't be crossed in lookups. Approved by: re Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-19 21:25:51 +00:00
if ((cnp->cn_flags & NOMACCHECK) == 0) {
Remove the thread argument from the FSD (File-System Dependent) parts of the VFS. Now all the VFS_* functions and relating parts don't want the context as long as it always refers to curthread. In some points, in particular when dealing with VOPs and functions living in the same namespace (eg. vflush) which still need to be converted, pass curthread explicitly in order to retain the old behaviour. Such loose ends will be fixed ASAP. While here fix a bug: now, UFS_EXTATTR can be compiled alone without the UFS_EXTATTR_AUTOSTART option. VFS KPI is heavilly changed by this commit so thirdy parts modules needs to be recompiled. Bump __FreeBSD_version in order to signal such situation.
2009-05-11 15:33:26 +00:00
error = mac_vnode_check_lookup(cnp->cn_thread->td_ucred, dp,
cnp);
Add a new 'NOMACCHECK' flag to namei() NDINIT flags, which permits the caller to indicate that MAC checks are not required for the lookup. Similar to IO_NOMACCHECK for vn_rdwr(), this indicates that the caller has already performed all required protections and that this is an internally generated operation. This will be used by the NFS server code, as we don't currently enforce MAC protections against requests delivered via NFS. While here, add NOCROSSMOUNT to PARAMASK; apparently this was used at one point for name lookup flag checking, but isn't any longer or it would have triggered from the NFS server code passing it to indicate that mountpoints shouldn't be crossed in lookups. Approved by: re Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-19 21:25:51 +00:00
if (error)
goto bad;
}
Introduce support for Mandatory Access Control and extensible kernel access control. Authorize vop_readlink() and vop_lookup() activities during recursive path lookup via namei() via calls to appropriate MAC entry points. Obtained from: TrustedBSD Project Sponsored by: DARPA, NAI Labs
2002-08-01 01:21:40 +00:00
#endif
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
ndp->ni_dvp = dp;
This is the kernel Lite/2 commit. There are some requisite userland changes, so don't expect to be able to run the kernel as-is (very well) without the appropriate Lite/2 userland changes. The system boots and can mount UFS filesystems. Untested: ext2fs, msdosfs, NFS Known problems: Incorrect Berkeley ID strings in some files. Mount_std mounts will not work until the getfsent library routine is changed. Reviewed by: various people Submitted by: Jeffery Hsu <hsu@freebsd.org>
1997-02-10 02:22:35 +00:00
ndp->ni_vp = NULL;
Add a function vop_sharedlock which a copy of vop_nolock without the implementation #ifdef out. This can be used for now by NFS. As soon as all the other filesystems' locking is fixed, this can go away. Print the vnode address in vprint for easier debugging.
1997-04-04 17:46:21 +00:00
ASSERT_VOP_LOCKED(dp, "lookup");
- Set cn_lkflags to LK_SHARED in the LOOKUP_SHARED case so that we only acquire shared locks on intermediate directories. - For the LASTCN, we may have to LK_UPGRADE the parent directory before we lookup the last component. - Acquire VFS_ROOT and dp locks based on the cn_lkflag. Sponsored by: Isilon Systems, Inc.
2005-03-29 10:07:15 +00:00
/*
* If we have a shared lock we may need to upgrade the lock for the
* last operation.
*/
Below is slightly edited description of the LOR by Tor Egge: -------------------------- [Deadlock] is caused by a lock order reversal in vfs_lookup(), where [some] process is trying to lock a directory vnode, that is the parent directory of covered vnode) while holding an exclusive vnode lock on covering vnode. A simplified scenario: root fs var fs / A / (/var) D /var B /log (/var/log) E vfs lock C vfs lock F Within each file system, the lock order is clear: C->A->B and F->D->E When traversing across mounts, the system can choose between two lock orders, but everything must then follow that lock order: L1: C->A->B | +->F->D->E L2: F->D->E | +->C->A->B The lookup() process for namei("/var") mixes those two lock orders: VOP_LOOKUP() obtains B while A is held vfs_busy() obtains a shared lock on F while A and B are held (follows L1, violates L2) vput() releases lock on B VOP_UNLOCK() releases lock on A VFS_ROOT() obtains lock on D while shared lock on F is held vfs_unbusy() releases shared lock on F vn_lock() obtains lock on A while D is held (violates L1, follows L2) dounmount() follows L1 (B is locked while F is drained). Without unmount activity, vfs_busy() will always succeed without blocking and the deadlock isn't triggered (the system behaves as if L2 is followed). With unmount, you can get 4 processes in a deadlock: p1: holds D, want A (in lookup()) p2: holds shared lock on F, want D (in VFS_ROOT()) p3: holds B, want drain lock on F (in dounmount()) p4: holds A, want B (in VOP_LOOKUP()) You can have more than one instance of p2. The reversal was introduced in revision 1.81 of src/sys/kern/vfs_lookup.c and MFCed to revision 1.80.2.1, probably to avoid a cascade of vnode locks when nfs servers are dead (VFS_ROOT() just hangs) spreading to the root fs root vnode. - Tor Egge To fix the LOR, ups@ noted that when crossing the mount point, ni_dvp is actually not used by the callers of namei. Thus, placeholder deadfs vnode vp_crossmp is introduced that is filled into ni_dvp. Idea by: ups Reviewed by: tegge, ups, jeff, rwatson (mac interaction) Tested by: Peter Holm MFC after: 2 weeks
2007-01-22 11:25:22 +00:00
if (dp != vp_crossmp &&
Axe the 'thread' argument from VOP_ISLOCKED() and lockstatus() as it is always curthread. As KPI gets broken by this patch, manpages and __FreeBSD_version will be updated by further commits. Tested by: Andrea Barberio <insomniac at slackware dot it>
2008-02-25 18:45:57 +00:00
VOP_ISLOCKED(dp) == LK_SHARED &&
- Set cn_lkflags to LK_SHARED in the LOOKUP_SHARED case so that we only acquire shared locks on intermediate directories. - For the LASTCN, we may have to LK_UPGRADE the parent directory before we lookup the last component. - Acquire VFS_ROOT and dp locks based on the cn_lkflag. Sponsored by: Isilon Systems, Inc.
2005-03-29 10:07:15 +00:00
(cnp->cn_flags & ISLASTCN) && (cnp->cn_flags & LOCKPARENT))
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
vn_lock(dp, LK_UPGRADE|LK_RETRY);
Do not call the VOP_LOOKUP() for the doomed directory vnode. The vnode could be reclaimed while lock upgrade was performed. Sponsored by: The FreeBSD Foundation Reported and tested by: pho Diagnosed and reviewed by: rmacklem MFC after: 1 week
2013-04-01 09:59:38 +00:00
if ((dp->v_iflag & VI_DOOMED) != 0) {
error = ENOENT;
goto bad;
}
- Set cn_lkflags to LK_SHARED in the LOOKUP_SHARED case so that we only acquire shared locks on intermediate directories. - For the LASTCN, we may have to LK_UPGRADE the parent directory before we lookup the last component. - Acquire VFS_ROOT and dp locks based on the cn_lkflag. Sponsored by: Isilon Systems, Inc.
2005-03-29 10:07:15 +00:00
/*
* If we're looking up the last component and we need an exclusive
* lock, adjust our lkflags.
*/
Add a new internal mount flag (MNTK_EXTENDED_SHARED) to indicate that a filesystem supports additional operations using shared vnode locks. Currently this is used to enable shared locks for open() and close() of read-only file descriptors. - When an ISOPEN namei() request is performed with LOCKSHARED, use a shared vnode lock for the leaf vnode only if the mount point has the extended shared flag set. - Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but not O_CREAT. - Use a shared vnode lock around VOP_CLOSE() if the file was opened with O_RDONLY and the mountpoint has the extended shared flag set. - Adjust md(4) to upgrade the vnode lock on the vnode it gets back from vn_open() since it now may only have a shared vnode lock. - Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since FIFO's require exclusive vnode locks for their open() and close() routines. (My recent MPSAFE patches for UDF and cd9660 already included this change.) - Enable extended shared operations on UFS, cd9660, and UDF. Submitted by: ups Reviewed by: pjd (ZFS bits) MFC after: 1 month
2009-03-11 14:13:47 +00:00
if (needs_exclusive_leaf(dp->v_mount, cnp->cn_flags))
- Set cn_lkflags to LK_SHARED in the LOOKUP_SHARED case so that we only acquire shared locks on intermediate directories. - For the LASTCN, we may have to LK_UPGRADE the parent directory before we lookup the last component. - Acquire VFS_ROOT and dp locks based on the cn_lkflag. Sponsored by: Isilon Systems, Inc.
2005-03-29 10:07:15 +00:00
cnp->cn_lkflags = LK_EXCLUSIVE;
Make NAMEI_DIAGNOSTIC compile again and add a stragic vprint()
2004-12-03 12:15:39 +00:00
#ifdef NAMEI_DIAGNOSTIC
Replace all remaining calls to vprint(9) with vn_printf(9), and remove the old macro. MFC after: 1 month
2016-08-10 16:12:31 +00:00
vn_printf(dp, "lookup in ");
Make NAMEI_DIAGNOSTIC compile again and add a stragic vprint()
2004-12-03 12:15:39 +00:00
#endif
Fixes up the handling of shared vnode lock lookups in the NFS client, adds a FS type specific flag indicating that the FS supports shared vnode lock lookups, adds some logic in vfs_lookup.c to test this flag and set lock flags appropriately. - amd on 6.x is a non-starter (without this change). Using amd under heavy load results in a deadlock (with cascading vnode locks all the way to the root) very quickly. - This change should also fix the more general problem of cascading vnode deadlocks when an NFS server goes down. Ideally, we wouldn't need these changes, as enabling shared vnode lock lookups globally would work. Unfortunately, UFS, for example isn't ready for shared vnode lock lookups, crashing pretty quickly. This change is the result of discussions with Stephan Uphoff (ups@). Reviewed by: ups@
2006-09-13 18:39:09 +00:00
lkflags_save = cnp->cn_lkflags;
Add MNTK_LOOKUP_EXCL_DOTDOT struct mount flag, which specifies to the lookup code that dotdot lookups shall override any shared lock requests with the exclusive one. The flag is useful for filesystems which sometimes need to upgrade shared lock to exclusive inside the VOP_LOOKUP or later, which cannot be done safely for dotdot, due to dvp also locked and causing LOR. In collaboration with: pho MFC after: 3 weeks
2012-09-09 19:11:52 +00:00
cnp->cn_lkflags = compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags,
cnp->cn_flags);
Refactor the way we restore cn_lkflags; no functional changes. MFC after: 1 month Sponsored by: The FreeBSD Foundation
2016-03-12 09:05:43 +00:00
error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp);
cnp->cn_lkflags = lkflags_save;
if (error != 0) {
Split DIAGNOSTIC -> DIAGNOSTIC, INVARIANTS, and INVARIANT_SUPPORT as discussed on -hackers. Introduce 'KASSERT(assertion, ("panic message", args))' for simple check + panic. Reviewed by: msmith
1999-01-08 17:31:30 +00:00
KASSERT(ndp->ni_vp == NULL, ("leaf should be empty"));
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#ifdef NAMEI_DIAGNOSTIC
printf("not found\n");
#endif
if ((error == ENOENT) &&
- Replace v_flag with v_iflag and v_vflag - v_vflag is protected by the vnode lock and is used when synchronization with VOP calls is needed. - v_iflag is protected by interlock and is used for dealing with vnode management issues. These flags include X/O LOCK, FREE, DOOMED, etc. - All accesses to v_iflag and v_vflag have either been locked or marked with mp_fixme's. - Many ASSERT_VOP_LOCKED calls have been added where the locking was not clear. - Many functions in vfs_subr.c were restructured to provide for stronger locking. Idea stolen from: BSD/OS
2002-08-04 10:29:36 +00:00
(dp->v_vflag & VV_ROOT) && (dp->v_mount != NULL) &&
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
(dp->v_mount->mnt_flag & MNT_UNION)) {
tdp = dp;
dp = dp->v_mount->mnt_vnodecovered;
VREF(dp);
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
vput(tdp);
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
vn_lock(dp,
compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags |
Add MNTK_LOOKUP_EXCL_DOTDOT struct mount flag, which specifies to the lookup code that dotdot lookups shall override any shared lock requests with the exclusive one. The flag is useful for filesystems which sometimes need to upgrade shared lock to exclusive inside the VOP_LOOKUP or later, which cannot be done safely for dotdot, due to dvp also locked and causing LOR. In collaboration with: pho MFC after: 3 weeks
2012-09-09 19:11:52 +00:00
LK_RETRY, cnp->cn_flags));
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
goto unionlookup;
}
Fix autofs triggering problem. Assume you have an NFS server, 192.168.1.1, with share "share". This commit fixes a problem where "mkdir /net/192.168.1.1/share/meh" would return spurious error instead of creating the directory if the target filesystem wasn't mounted yet; subsequent attempts would work correctly. The failure scenario is kind of complicated to explain, but it all boils down to calling VOP_MKDIR() for the target filesystem (NFS) with wrong dvp - the autofs vnode instead of the filesystem root mounted over it. Reviewed by: kib@ MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D5442
2016-03-12 07:54:42 +00:00
if (error == ERELOOKUP) {
vref(dp);
ndp->ni_vp = dp;
error = 0;
relookup = 1;
goto good;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (error != EJUSTRETURN)
goto bad;
/*
Eliminate trailing_slash, which was made redundant in r193028. Remove a couple of 4-year-old "temporary" KASSERTs. Improve comments. MFC after: 1 week
2009-06-06 00:49:49 +00:00
* At this point, we know we're at the end of the
* pathname. If creating / renaming, we can consider
* allowing the file or directory to be created / renamed,
* provided we're not on a read-only filesystem.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
Moved the filesystem read-only check out of the syscalls and into the filesystem layer, as was done in lite-2. Merged in some other cosmetic changes while I was at it. Rewrote most of msdosfs_access() to be more like ufs_access() and to include the FS read-only check. Obtained from: partially from 4.4BSD-lite2
1995-10-22 09:32:48 +00:00
if (rdonly) {
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
error = EROFS;
goto bad;
}
Eliminate trailing_slash, which was made redundant in r193028. Remove a couple of 4-year-old "temporary" KASSERTs. Improve comments. MFC after: 1 week
2009-06-06 00:49:49 +00:00
/* trailing slash only allowed for directories */
if ((cnp->cn_flags & TRAILINGSLASH) &&
!(cnp->cn_flags & WILLBEDIR)) {
Ignore trailing slashes in pathnames that "refer to a directory", as is required to be POSIXLY_CORRECT and "right". I interpret "referring to a directory" as being a directory or becoming a directory. E.g., the trailing slashes in mkdir("/nonesuch/"), rename("/tmp", /nonesuch/") and link("/tmp", "/root_can_like_dirs/") are ignored because the target will become a directory if the syscall succeeds. A trailing slash on a symlink causes the symlink to be followed (this is a bug if the symlink doesn't point to a directory; fix later).
1995-07-31 00:35:58 +00:00
error = ENOENT;
goto bad;
}
- Get rid of PDIRUNLOCK, instead, we fixup the lock state immediately after calling VOP_LOOKUP(). Rather than having each filesystem check the LOCKPARENT flag, we simply check it once here and unlock as required. The only unusual case is ISDOTDOT, where we require an unlocked vnode on return. Relocking this vnode with the child locked is allowed since the child is actually its parent. - Add a few asserts for some unusual conditions that I do not believe can happen. These will later go away and turn into implementations for these conditions. Sponsored by: Isilon Systems, Inc.
2005-03-28 09:24:50 +00:00
if ((cnp->cn_flags & LOCKPARENT) == 0)
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(dp, 0);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
* We return with ni_vp NULL to indicate that the entry
* doesn't currently exist, leaving a pointer to the
We now spell "inode" as "vnode" in the VFS layer, so update comment for new world order. MFC after: 3 days Pointed out by: mckusick
2006-08-05 21:08:47 +00:00
* (possibly locked) directory vnode in ndp->ni_dvp.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
if (cnp->cn_flags & SAVESTART) {
ndp->ni_startdir = ndp->ni_dvp;
VREF(ndp->ni_startdir);
}
- Acquire and release Giant as we enter and leave filesystems which require it. - Track the status of Giant with the nd flag HASGIANT. - Release giant on return of namei() callers are not marked MPSAFE as they already own giant. Sponsored By: Isilon Systems, Inc.
2005-01-24 10:27:05 +00:00
goto success;
Refactor the way we restore cn_lkflags; no functional changes. MFC after: 1 month Sponsored by: The FreeBSD Foundation
2016-03-12 09:05:43 +00:00
}
Fix autofs triggering problem. Assume you have an NFS server, 192.168.1.1, with share "share". This commit fixes a problem where "mkdir /net/192.168.1.1/share/meh" would return spurious error instead of creating the directory if the target filesystem wasn't mounted yet; subsequent attempts would work correctly. The failure scenario is kind of complicated to explain, but it all boils down to calling VOP_MKDIR() for the target filesystem (NFS) with wrong dvp - the autofs vnode instead of the filesystem root mounted over it. Reviewed by: kib@ MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D5442
2016-03-12 07:54:42 +00:00
good:
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#ifdef NAMEI_DIAGNOSTIC
printf("found\n");
#endif
dp = ndp->ni_vp;
Ignore trailing slashes in pathnames that "refer to a directory", as is required to be POSIXLY_CORRECT and "right". I interpret "referring to a directory" as being a directory or becoming a directory. E.g., the trailing slashes in mkdir("/nonesuch/"), rename("/tmp", /nonesuch/") and link("/tmp", "/root_can_like_dirs/") are ignored because the target will become a directory if the syscall succeeds. A trailing slash on a symlink causes the symlink to be followed (this is a bug if the symlink doesn't point to a directory; fix later).
1995-07-31 00:35:58 +00:00
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
* Check to see if the vnode has been mounted on;
More s/file system/filesystem/g
2002-05-16 21:28:32 +00:00
* if so find the root of the mounted filesystem.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
while (dp->v_type == VDIR && (mp = dp->v_mountedhere) &&
(cnp->cn_flags & NOCROSSMOUNT) == 0) {
Improve VFS locking: - Implement real draining for vfs consumers by not relying on the mnt_lock and using instead a refcount in order to keep track of lock requesters. - Due to the change above, remove the mnt_lock lockmgr because it is now useless. - Due to the change above, vfs_busy() is no more linked to a lockmgr. Change so its KPI by removing the interlock argument and defining 2 new flags for it: MBF_NOWAIT which basically replaces the LK_NOWAIT of the old version (which was unlinked from the lockmgr alredy) and MBF_MNTLSTLOCK which provides the ability to drop the mountlist_mtx once the mnt interlock is held (ability still desired by most consumers). - The stub used into vfs_mount_destroy(), that allows to override the mnt_ref if running for more than 3 seconds, make it totally useless. Remove it as it was thought to work into older versions. If a problem of "refcount held never going away" should appear, we will need to fix properly instead than trust on such hackish solution. - Fix a bug where returning (with an error) from dounmount() was still leaving the MNTK_MWAIT flag on even if it the waiters were actually woken up. Just a place in vfs_mount_destroy() is left because it is going to recycle the structure in any case, so it doesn't matter. - Remove the markercnt refcount as it is useless. This patch modifies VFS ABI and breaks KPI for vfs_busy() so manpages and __FreeBSD_version will be modified accordingly. Discussed with: kib Tested by: pho
2008-11-02 10:15:42 +00:00
if (vfs_busy(mp, 0))
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
continue;
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
vput(dp);
- Consistently track ni_dvp and ni_vp with dvfslocked and vfslocked rather than trying to optimize it into a single lock. This adds more calls to lock giant with non smpsafe filesystems but is the only way to reliably hold the correct lock. - Remove an invalid assert in the mountedhere case in lookup and fix the code to properly deal with the scenario. We can actually have a lookup that returns dp == dvp with mountedhere set with certain unmount races. Tested by: kris Reported by: kris/mohans
2006-04-28 00:59:48 +00:00
if (dp != ndp->ni_dvp)
Below is slightly edited description of the LOR by Tor Egge: -------------------------- [Deadlock] is caused by a lock order reversal in vfs_lookup(), where [some] process is trying to lock a directory vnode, that is the parent directory of covered vnode) while holding an exclusive vnode lock on covering vnode. A simplified scenario: root fs var fs / A / (/var) D /var B /log (/var/log) E vfs lock C vfs lock F Within each file system, the lock order is clear: C->A->B and F->D->E When traversing across mounts, the system can choose between two lock orders, but everything must then follow that lock order: L1: C->A->B | +->F->D->E L2: F->D->E | +->C->A->B The lookup() process for namei("/var") mixes those two lock orders: VOP_LOOKUP() obtains B while A is held vfs_busy() obtains a shared lock on F while A and B are held (follows L1, violates L2) vput() releases lock on B VOP_UNLOCK() releases lock on A VFS_ROOT() obtains lock on D while shared lock on F is held vfs_unbusy() releases shared lock on F vn_lock() obtains lock on A while D is held (violates L1, follows L2) dounmount() follows L1 (B is locked while F is drained). Without unmount activity, vfs_busy() will always succeed without blocking and the deadlock isn't triggered (the system behaves as if L2 is followed). With unmount, you can get 4 processes in a deadlock: p1: holds D, want A (in lookup()) p2: holds shared lock on F, want D (in VFS_ROOT()) p3: holds B, want drain lock on F (in dounmount()) p4: holds A, want B (in VOP_LOOKUP()) You can have more than one instance of p2. The reversal was introduced in revision 1.81 of src/sys/kern/vfs_lookup.c and MFCed to revision 1.80.2.1, probably to avoid a cascade of vnode locks when nfs servers are dead (VFS_ROOT() just hangs) spreading to the root fs root vnode. - Tor Egge To fix the LOR, ups@ noted that when crossing the mount point, ni_dvp is actually not used by the callers of namei. Thus, placeholder deadfs vnode vp_crossmp is introduced that is filled into ni_dvp. Idea by: ups Reviewed by: tegge, ups, jeff, rwatson (mac interaction) Tested by: Peter Holm MFC after: 2 weeks
2007-01-22 11:25:22 +00:00
vput(ndp->ni_dvp);
else
vrele(ndp->ni_dvp);
vref(vp_crossmp);
ndp->ni_dvp = vp_crossmp;
Add MNTK_LOOKUP_EXCL_DOTDOT struct mount flag, which specifies to the lookup code that dotdot lookups shall override any shared lock requests with the exclusive one. The flag is useful for filesystems which sometimes need to upgrade shared lock to exclusive inside the VOP_LOOKUP or later, which cannot be done safely for dotdot, due to dvp also locked and causing LOR. In collaboration with: pho MFC after: 3 weeks
2012-09-09 19:11:52 +00:00
error = VFS_ROOT(mp, compute_cn_lkflags(mp, cnp->cn_lkflags,
cnp->cn_flags), &tdp);
Decontextualize vfs_busy(), vfs_unbusy() and vfs_mount_alloc() functions. Manpages are updated accordingly. Tested by: Diego Sardina <siarodx at gmail dot com>
2008-08-31 14:26:08 +00:00
vfs_unbusy(mp);
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
if (vn_lock(vp_crossmp, LK_SHARED | LK_NOWAIT))
Below is slightly edited description of the LOR by Tor Egge: -------------------------- [Deadlock] is caused by a lock order reversal in vfs_lookup(), where [some] process is trying to lock a directory vnode, that is the parent directory of covered vnode) while holding an exclusive vnode lock on covering vnode. A simplified scenario: root fs var fs / A / (/var) D /var B /log (/var/log) E vfs lock C vfs lock F Within each file system, the lock order is clear: C->A->B and F->D->E When traversing across mounts, the system can choose between two lock orders, but everything must then follow that lock order: L1: C->A->B | +->F->D->E L2: F->D->E | +->C->A->B The lookup() process for namei("/var") mixes those two lock orders: VOP_LOOKUP() obtains B while A is held vfs_busy() obtains a shared lock on F while A and B are held (follows L1, violates L2) vput() releases lock on B VOP_UNLOCK() releases lock on A VFS_ROOT() obtains lock on D while shared lock on F is held vfs_unbusy() releases shared lock on F vn_lock() obtains lock on A while D is held (violates L1, follows L2) dounmount() follows L1 (B is locked while F is drained). Without unmount activity, vfs_busy() will always succeed without blocking and the deadlock isn't triggered (the system behaves as if L2 is followed). With unmount, you can get 4 processes in a deadlock: p1: holds D, want A (in lookup()) p2: holds shared lock on F, want D (in VFS_ROOT()) p3: holds B, want drain lock on F (in dounmount()) p4: holds A, want B (in VOP_LOOKUP()) You can have more than one instance of p2. The reversal was introduced in revision 1.81 of src/sys/kern/vfs_lookup.c and MFCed to revision 1.80.2.1, probably to avoid a cascade of vnode locks when nfs servers are dead (VFS_ROOT() just hangs) spreading to the root fs root vnode. - Tor Egge To fix the LOR, ups@ noted that when crossing the mount point, ni_dvp is actually not used by the callers of namei. Thus, placeholder deadfs vnode vp_crossmp is introduced that is filled into ni_dvp. Idea by: ups Reviewed by: tegge, ups, jeff, rwatson (mac interaction) Tested by: Peter Holm MFC after: 2 weeks
2007-01-22 11:25:22 +00:00
panic("vp_crossmp exclusively locked or reclaimed");
Unlock current directory when calling VFS_ROOT() because underlying filesystem may hold the lock. Otherwise unavoidable deadlock will occur. This shouldn't have any side effects as long as we hold vfs lock. Obtained from: NetBSD
2000-09-13 08:57:56 +00:00
if (error) {
dpunlocked = 1;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
goto bad2;
Unlock current directory when calling VFS_ROOT() because underlying filesystem may hold the lock. Otherwise unavoidable deadlock will occur. This shouldn't have any side effects as long as we hold vfs lock. Obtained from: NetBSD
2000-09-13 08:57:56 +00:00
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
ndp->ni_vp = dp = tdp;
}
Add support for amd direct maps. Reviewed by: Thomas Graichen <graichen@sirius.physik.fu-berlin.de>
1995-08-24 10:17:39 +00:00
/*
* Check for symbolic link
*/
if ((dp->v_type == VLNK) &&
Eliminate trailing_slash, which was made redundant in r193028. Remove a couple of 4-year-old "temporary" KASSERTs. Improve comments. MFC after: 1 week
2009-06-06 00:49:49 +00:00
((cnp->cn_flags & FOLLOW) || (cnp->cn_flags & TRAILINGSLASH) ||
Add support for amd direct maps. Reviewed by: Thomas Graichen <graichen@sirius.physik.fu-berlin.de>
1995-08-24 10:17:39 +00:00
*ndp->ni_next == '/')) {
cnp->cn_flags |= ISSYMLINK;
- Don't check v_mount for NULL to determine if a vnode has been recycled. Use the more appropriate VI_DOOMED flag instead. Sponsored by: Isilon Systems, Inc. MFC After: 1 week
2006-02-06 10:15:27 +00:00
if (dp->v_iflag & VI_DOOMED) {
When a file lookup fails due to encountering a doomed vnode from a forced unmount, consistently return ENOENT rather than EBADF. Reviewed by: kib MFC after: 1 month
2009-03-24 18:16:42 +00:00
/*
* We can't know whether the directory was mounted with
* NOSYMFOLLOW, so we can't follow safely.
*/
error = ENOENT;
This is a fix for a problem described in PR kern/19572. It was recently discussed at -hackers. The problem is a null-pointer dereference that happens in kern/vfs_lookup.c when accessing ".." with a v_mount entry for the current directory vnode of NULL. This happens when a volume is forcibly unmounted, and the vnode for a working directory in the mounted volume is cleared. PR: 23191 Submitted by: Thomas Moestl <tmoestl@gmx.net>
2000-11-30 20:04:44 +00:00
goto bad2;
}
New mount option nosymfollow. If enabled, the kernel lookup() function will not follow symbolic links on the mounted file system and return EACCES (Permission denied).
1998-04-08 18:31:59 +00:00
if (dp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) {
error = EACCES;
goto bad2;
}
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
/*
* Symlink code always expects an unlocked dvp.
*/
Avoid double-unlock or double unreference for ndp->ni_dvp when the vnode dp lock upgrade right after the 'success' label fails. In collaboration with: pho MFC after: 1 week
2012-01-01 18:45:59 +00:00
if (ndp->ni_dvp != ndp->ni_vp) {
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(ndp->ni_dvp, 0);
Avoid double-unlock or double unreference for ndp->ni_dvp when the vnode dp lock upgrade right after the 'success' label fails. In collaboration with: pho MFC after: 1 week
2012-01-01 18:45:59 +00:00
ni_dvp_unlocked = 1;
}
- Acquire and release Giant as we enter and leave filesystems which require it. - Track the status of Giant with the nd flag HASGIANT. - Release giant on return of namei() callers are not marked MPSAFE as they already own giant. Sponsored By: Isilon Systems, Inc.
2005-01-24 10:27:05 +00:00
goto success;
Add support for amd direct maps. Reviewed by: Thomas Graichen <graichen@sirius.physik.fu-berlin.de>
1995-08-24 10:17:39 +00:00
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
nextname:
/*
Eliminate trailing_slash, which was made redundant in r193028. Remove a couple of 4-year-old "temporary" KASSERTs. Improve comments. MFC after: 1 week
2009-06-06 00:49:49 +00:00
* Not a symbolic link that we will follow. Continue with the
* next component if there is any; otherwise, we're done.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
- Get rid of PDIRUNLOCK, instead, we fixup the lock state immediately after calling VOP_LOOKUP(). Rather than having each filesystem check the LOCKPARENT flag, we simply check it once here and unlock as required. The only unusual case is ISDOTDOT, where we require an unlocked vnode on return. Relocking this vnode with the child locked is allowed since the child is actually its parent. - Add a few asserts for some unusual conditions that I do not believe can happen. These will later go away and turn into implementations for these conditions. Sponsored by: Isilon Systems, Inc.
2005-03-28 09:24:50 +00:00
KASSERT((cnp->cn_flags & ISLASTCN) || *ndp->ni_next == '/',
("lookup: invalid path state."));
Fix autofs triggering problem. Assume you have an NFS server, 192.168.1.1, with share "share". This commit fixes a problem where "mkdir /net/192.168.1.1/share/meh" would return spurious error instead of creating the directory if the target filesystem wasn't mounted yet; subsequent attempts would work correctly. The failure scenario is kind of complicated to explain, but it all boils down to calling VOP_MKDIR() for the target filesystem (NFS) with wrong dvp - the autofs vnode instead of the filesystem root mounted over it. Reviewed by: kib@ MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D5442
2016-03-12 07:54:42 +00:00
if (relookup) {
relookup = 0;
if (ndp->ni_dvp != dp)
vput(ndp->ni_dvp);
else
vrele(ndp->ni_dvp);
goto dirloop;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if (*ndp->ni_next == '/') {
cnp->cn_nameptr = ndp->ni_next;
while (*cnp->cn_nameptr == '/') {
cnp->cn_nameptr++;
ndp->ni_pathlen--;
}
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
if (ndp->ni_dvp != dp)
vput(ndp->ni_dvp);
else
vrele(ndp->ni_dvp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
goto dirloop;
}
Let vfs_lookup() return ENOTDIR if the path has a trailing slash and the last component is a symlink to something that isn't a directory. We introduce a new namei flag, TRAILINGSLASH, which is set by lookup() if the last component is followed by a slash. The trailing slash is then stripped, as before. If the final component is a symlink, lookup() will return to namei(), which will expand the symlink and call lookup() with the new path. When all symlinks have been resolved, lookup() checks if the TRAILINGSLASH flag is set, and if it is, and the vnode it ended up with is not a directory, it returns ENOTDIR. PR: kern/21768 Submitted by: Eygene Ryabinkin <rea-fbsd@codelabs.ru> MFC after: 3 weeks
2009-05-29 10:02:44 +00:00
/*
* If we're processing a path with a trailing slash,
* check that the end result is a directory.
*/
if ((cnp->cn_flags & TRAILINGSLASH) && dp->v_type != VDIR) {
error = ENOTDIR;
goto bad2;
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
More s/file system/filesystem/g
2002-05-16 21:28:32 +00:00
* Disallow directory write attempts on read-only filesystems.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
Moved the filesystem read-only check out of the syscalls and into the filesystem layer, as was done in lite-2. Merged in some other cosmetic changes while I was at it. Rewrote most of msdosfs_access() to be more like ufs_access() and to include the FS read-only check. Obtained from: partially from 4.4BSD-lite2
1995-10-22 09:32:48 +00:00
if (rdonly &&
(cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
error = EROFS;
goto bad2;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
if (cnp->cn_flags & SAVESTART) {
ndp->ni_startdir = ndp->ni_dvp;
VREF(ndp->ni_startdir);
}
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
if (!wantparent) {
Avoid double-unlock or double unreference for ndp->ni_dvp when the vnode dp lock upgrade right after the 'success' label fails. In collaboration with: pho MFC after: 1 week
2012-01-01 18:45:59 +00:00
ni_dvp_unlocked = 2;
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
if (ndp->ni_dvp != dp)
vput(ndp->ni_dvp);
else
vrele(ndp->ni_dvp);
Avoid double-unlock or double unreference for ndp->ni_dvp when the vnode dp lock upgrade right after the 'success' label fails. In collaboration with: pho MFC after: 1 week
2012-01-01 18:45:59 +00:00
} else if ((cnp->cn_flags & LOCKPARENT) == 0 && ndp->ni_dvp != dp) {
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(ndp->ni_dvp, 0);
Avoid double-unlock or double unreference for ndp->ni_dvp when the vnode dp lock upgrade right after the 'success' label fails. In collaboration with: pho MFC after: 1 week
2012-01-01 18:45:59 +00:00
ni_dvp_unlocked = 1;
}
Lots of improvements, including restructring the caching and management of vnodes and objects. There are some metadata performance improvements that come along with this. There are also a few prototypes added when the need is noticed. Changes include: 1) Cleaning up vref, vget. 2) Removal of the object cache. 3) Nuke vnode_pager_uncache and friends, because they aren't needed anymore. 4) Correct some missing LK_RETRY's in vn_lock. 5) Correct the page range in the code for msync. Be gentle, and please give me feedback asap.
1997-12-29 00:25:11 +00:00
Add AUDITVNODE[12] flags to namei(), which cause namei() to audit path and vnode attribute information for looked up vnodes during the lookup operation. This will allow consumers of namei() to specify that this information be added to the in-process audit record. Submitted by: wsalamon Obtained from: TrustedBSD Project
2006-02-05 15:42:01 +00:00
if (cnp->cn_flags & AUDITVNODE1)
Rework vnode argument auditing to follow the same structure, in order to avoid exposing ARG_ macros/flag values outside of the audit code in order to name which one of two possible vnodes will be audited for a system call. Approved by: re (kib) Obtained from: TrustedBSD Project MFC after: 1 month
2009-07-28 21:52:24 +00:00
AUDIT_ARG_VNODE1(dp);
Add AUDITVNODE[12] flags to namei(), which cause namei() to audit path and vnode attribute information for looked up vnodes during the lookup operation. This will allow consumers of namei() to specify that this information be added to the in-process audit record. Submitted by: wsalamon Obtained from: TrustedBSD Project
2006-02-05 15:42:01 +00:00
else if (cnp->cn_flags & AUDITVNODE2)
Rework vnode argument auditing to follow the same structure, in order to avoid exposing ARG_ macros/flag values outside of the audit code in order to name which one of two possible vnodes will be audited for a system call. Approved by: re (kib) Obtained from: TrustedBSD Project MFC after: 1 month
2009-07-28 21:52:24 +00:00
AUDIT_ARG_VNODE2(dp);
Add AUDITVNODE[12] flags to namei(), which cause namei() to audit path and vnode attribute information for looked up vnodes during the lookup operation. This will allow consumers of namei() to specify that this information be added to the in-process audit record. Submitted by: wsalamon Obtained from: TrustedBSD Project
2006-02-05 15:42:01 +00:00
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
if ((cnp->cn_flags & LOCKLEAF) == 0)
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(dp, 0);
- Acquire and release Giant as we enter and leave filesystems which require it. - Track the status of Giant with the nd flag HASGIANT. - Release giant on return of namei() callers are not marked MPSAFE as they already own giant. Sponsored By: Isilon Systems, Inc.
2005-01-24 10:27:05 +00:00
success:
Fix some locking cases where we ask for exclusively locked vnode, but we get shared locked vnode in instead when vfs.lookup_shared is set to 1. Discussed with: kib, kris Tested by: kris Approved by: re (kensmith)
2007-09-21 10:16:56 +00:00
/*
* Because of lookup_shared we may have the vnode shared locked, but
* the caller may want it to be exclusively locked.
*/
Add a new internal mount flag (MNTK_EXTENDED_SHARED) to indicate that a filesystem supports additional operations using shared vnode locks. Currently this is used to enable shared locks for open() and close() of read-only file descriptors. - When an ISOPEN namei() request is performed with LOCKSHARED, use a shared vnode lock for the leaf vnode only if the mount point has the extended shared flag set. - Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but not O_CREAT. - Use a shared vnode lock around VOP_CLOSE() if the file was opened with O_RDONLY and the mountpoint has the extended shared flag set. - Adjust md(4) to upgrade the vnode lock on the vnode it gets back from vn_open() since it now may only have a shared vnode lock. - Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since FIFO's require exclusive vnode locks for their open() and close() routines. (My recent MPSAFE patches for UDF and cd9660 already included this change.) - Enable extended shared operations on UFS, cd9660, and UDF. Submitted by: ups Reviewed by: pjd (ZFS bits) MFC after: 1 month
2009-03-11 14:13:47 +00:00
if (needs_exclusive_leaf(dp->v_mount, cnp->cn_flags) &&
VOP_ISLOCKED(dp) != LK_EXCLUSIVE) {
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
vn_lock(dp, LK_UPGRADE | LK_RETRY);
Do not return success and doomed vnode from lookup. LK_UPGRADE allows the vnode to be reclaimed. Tested by: pho MFC after: 1 month
2008-12-18 11:58:12 +00:00
if (dp->v_iflag & VI_DOOMED) {
error = ENOENT;
goto bad2;
}
Fix some locking cases where we ask for exclusively locked vnode, but we get shared locked vnode in instead when vfs.lookup_shared is set to 1. Discussed with: kib, kris Tested by: kris Approved by: re (kensmith)
2007-09-21 10:16:56 +00:00
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
return (0);
bad2:
Avoid double-unlock or double unreference for ndp->ni_dvp when the vnode dp lock upgrade right after the 'success' label fails. In collaboration with: pho MFC after: 1 week
2012-01-01 18:45:59 +00:00
if (ni_dvp_unlocked != 2) {
if (dp != ndp->ni_dvp && !ni_dvp_unlocked)
vput(ndp->ni_dvp);
else
vrele(ndp->ni_dvp);
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
bad:
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
if (!dpunlocked)
Unlock current directory when calling VFS_ROOT() because underlying filesystem may hold the lock. Otherwise unavoidable deadlock will occur. This shouldn't have any side effects as long as we hold vfs lock. Obtained from: NetBSD
2000-09-13 08:57:56 +00:00
vput(dp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
ndp->ni_vp = NULL;
return (error);
}
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
/*
* relookup - lookup a path name component
Universally adopt most conventional spelling of acquire.
2007-05-27 20:50:23 +00:00
* Used by lookup to re-acquire things.
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
*/
int
Remove register, use ANSI function headers.
2006-08-05 21:40:59 +00:00
relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp)
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
{
kern: for pointers replace 0 with NULL. These are mostly cosmetical, no functional change. Found with devel/coccinelle.
2016-04-15 16:10:11 +00:00
struct vnode *dp = NULL; /* the directory we are searching */
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
int wantparent; /* 1 => wantparent or lockparent flag */
int rdonly; /* lookup read-only flag bit */
int error = 0;
- Get rid of PDIRUNLOCK, instead, we fixup the lock state immediately after calling VOP_LOOKUP(). Rather than having each filesystem check the LOCKPARENT flag, we simply check it once here and unlock as required. The only unusual case is ISDOTDOT, where we require an unlocked vnode on return. Relocking this vnode with the child locked is allowed since the child is actually its parent. - Add a few asserts for some unusual conditions that I do not believe can happen. These will later go away and turn into implementations for these conditions. Sponsored by: Isilon Systems, Inc.
2005-03-28 09:24:50 +00:00
KASSERT(cnp->cn_flags & ISLASTCN,
("relookup: Not given last component."));
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
/*
* Setup: break out flag bits into variables.
*/
wantparent = cnp->cn_flags & (LOCKPARENT|WANTPARENT);
- Further simplify lookup; Force all filesystems to relock in the DOTDOT case. There are bugs in some which didn't unlock in the ISDOTDOT case to begin with that need to be addressed seperately. This simplifies things anyway. - Fix relookup() to prevent it from vrele()'ing the dvp while the vp is locked. Catch up to other lookup changes. Sponsored by: Isilon Systems, Inc. Reported by: Peter Wemm
2005-04-13 10:57:13 +00:00
KASSERT(wantparent, ("relookup: parent not wanted."));
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
rdonly = cnp->cn_flags & RDONLY;
cnp->cn_flags &= ~ISSYMLINK;
dp = dvp;
- Set cn_lkflags to LK_SHARED in the LOOKUP_SHARED case so that we only acquire shared locks on intermediate directories. - For the LASTCN, we may have to LK_UPGRADE the parent directory before we lookup the last component. - Acquire VFS_ROOT and dp locks based on the cn_lkflag. Sponsored by: Isilon Systems, Inc.
2005-03-29 10:07:15 +00:00
cnp->cn_lkflags = LK_EXCLUSIVE;
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
vn_lock(dp, LK_EXCLUSIVE | LK_RETRY);
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
/*
* Search a new directory.
*
* The last component of the filename is left accessible via
* cnp->cn_nameptr for callers that need the name. Callers needing
* the name set the SAVENAME flag. When done, they assume
* responsibility for freeing the pathname buffer.
*/
#ifdef NAMEI_DIAGNOSTIC
printf("{%s}: ", cnp->cn_nameptr);
#endif
/*
Support only LOOKUP operation for "/" in relookup() because lookup() can't succeed for CREATE, DELETE and RENAME. Discussed with: bde
2010-03-26 11:33:12 +00:00
* Check for "" which represents the root directory after slash
* removal.
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
*/
if (cnp->cn_nameptr[0] == '\0') {
Support only LOOKUP operation for "/" in relookup() because lookup() can't succeed for CREATE, DELETE and RENAME. Discussed with: bde
2010-03-26 11:33:12 +00:00
/*
* Support only LOOKUP for "/" because lookup()
* can't succeed for CREATE, DELETE and RENAME.
*/
KASSERT(cnp->cn_nameiop == LOOKUP, ("nameiop must be LOOKUP"));
KASSERT(dp->v_type == VDIR, ("dp is not a directory"));
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
if (!(cnp->cn_flags & LOCKLEAF))
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(dp, 0);
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
*vpp = dp;
Introduce NDFREE (and remove VOP_ABORTOP)
1999-12-15 23:02:35 +00:00
/* XXX This should probably move to the top of function. */
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
if (cnp->cn_flags & SAVESTART)
panic("lookup: SAVESTART");
return (0);
}
if (cnp->cn_flags & ISDOTDOT)
panic ("relookup: lookup on dot-dot");
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
/*
* We now have a segment name to search for, and a directory to search.
*/
Make NAMEI_DIAGNOSTIC compile again and add a stragic vprint()
2004-12-03 12:15:39 +00:00
#ifdef NAMEI_DIAGNOSTIC
Replace all remaining calls to vprint(9) with vn_printf(9), and remove the old macro. MFC after: 1 month
2016-08-10 16:12:31 +00:00
vn_printf(dp, "search in ");
Make NAMEI_DIAGNOSTIC compile again and add a stragic vprint()
2004-12-03 12:15:39 +00:00
#endif
Fix warnings in preparation for adding -Wall -Wcast-qual to the kernel compile
1999-01-28 00:57:57 +00:00
if ((error = VOP_LOOKUP(dp, vpp, cnp)) != 0) {
Split DIAGNOSTIC -> DIAGNOSTIC, INVARIANTS, and INVARIANT_SUPPORT as discussed on -hackers. Introduce 'KASSERT(assertion, ("panic message", args))' for simple check + panic. Reviewed by: msmith
1999-01-08 17:31:30 +00:00
KASSERT(*vpp == NULL, ("leaf should be empty"));
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
if (error != EJUSTRETURN)
goto bad;
/*
* If creating and at end of pathname, then can consider
* allowing file to be created.
*/
Moved the filesystem read-only check out of the syscalls and into the filesystem layer, as was done in lite-2. Merged in some other cosmetic changes while I was at it. Rewrote most of msdosfs_access() to be more like ufs_access() and to include the FS read-only check. Obtained from: partially from 4.4BSD-lite2
1995-10-22 09:32:48 +00:00
if (rdonly) {
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
error = EROFS;
goto bad;
}
/* ASSERT(dvp == ndp->ni_startdir) */
if (cnp->cn_flags & SAVESTART)
VREF(dvp);
- Get rid of PDIRUNLOCK, instead, we fixup the lock state immediately after calling VOP_LOOKUP(). Rather than having each filesystem check the LOCKPARENT flag, we simply check it once here and unlock as required. The only unusual case is ISDOTDOT, where we require an unlocked vnode on return. Relocking this vnode with the child locked is allowed since the child is actually its parent. - Add a few asserts for some unusual conditions that I do not believe can happen. These will later go away and turn into implementations for these conditions. Sponsored by: Isilon Systems, Inc.
2005-03-28 09:24:50 +00:00
if ((cnp->cn_flags & LOCKPARENT) == 0)
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(dp, 0);
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
/*
* We return with ni_vp NULL to indicate that the entry
* doesn't currently exist, leaving a pointer to the
We now spell "inode" as "vnode" in the VFS layer, so update comment for new world order. MFC after: 3 days Pointed out by: mckusick
2006-08-05 21:08:47 +00:00
* (possibly locked) directory vnode in ndp->ni_dvp.
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
*/
return (0);
}
Fixes up the handling of shared vnode lock lookups in the NFS client, adds a FS type specific flag indicating that the FS supports shared vnode lock lookups, adds some logic in vfs_lookup.c to test this flag and set lock flags appropriately. - amd on 6.x is a non-starter (without this change). Using amd under heavy load results in a deadlock (with cascading vnode locks all the way to the root) very quickly. - This change should also fix the more general problem of cascading vnode deadlocks when an NFS server goes down. Ideally, we wouldn't need these changes, as enabling shared vnode lock lookups globally would work. Unfortunately, UFS, for example isn't ready for shared vnode lock lookups, crashing pretty quickly. This change is the result of discussions with Stephan Uphoff (ups@). Reviewed by: ups@
2006-09-13 18:39:09 +00:00
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
dp = *vpp;
/*
More s/file system/filesystem/g
2002-05-16 21:28:32 +00:00
* Disallow directory write attempts on read-only filesystems.
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
*/
Moved the filesystem read-only check out of the syscalls and into the filesystem layer, as was done in lite-2. Merged in some other cosmetic changes while I was at it. Rewrote most of msdosfs_access() to be more like ufs_access() and to include the FS read-only check. Obtained from: partially from 4.4BSD-lite2
1995-10-22 09:32:48 +00:00
if (rdonly &&
(cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
- Further simplify lookup; Force all filesystems to relock in the DOTDOT case. There are bugs in some which didn't unlock in the ISDOTDOT case to begin with that need to be addressed seperately. This simplifies things anyway. - Fix relookup() to prevent it from vrele()'ing the dvp while the vp is locked. Catch up to other lookup changes. Sponsored by: Isilon Systems, Inc. Reported by: Peter Wemm
2005-04-13 10:57:13 +00:00
if (dvp == dp)
vrele(dvp);
else
vput(dvp);
Moved the filesystem read-only check out of the syscalls and into the filesystem layer, as was done in lite-2. Merged in some other cosmetic changes while I was at it. Rewrote most of msdosfs_access() to be more like ufs_access() and to include the FS read-only check. Obtained from: partially from 4.4BSD-lite2
1995-10-22 09:32:48 +00:00
error = EROFS;
- Further simplify lookup; Force all filesystems to relock in the DOTDOT case. There are bugs in some which didn't unlock in the ISDOTDOT case to begin with that need to be addressed seperately. This simplifies things anyway. - Fix relookup() to prevent it from vrele()'ing the dvp while the vp is locked. Catch up to other lookup changes. Sponsored by: Isilon Systems, Inc. Reported by: Peter Wemm
2005-04-13 10:57:13 +00:00
goto bad;
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
}
- Further simplify lookup; Force all filesystems to relock in the DOTDOT case. There are bugs in some which didn't unlock in the ISDOTDOT case to begin with that need to be addressed seperately. This simplifies things anyway. - Fix relookup() to prevent it from vrele()'ing the dvp while the vp is locked. Catch up to other lookup changes. Sponsored by: Isilon Systems, Inc. Reported by: Peter Wemm
2005-04-13 10:57:13 +00:00
/*
* Set the parent lock/ref state to the requested state.
*/
if ((cnp->cn_flags & LOCKPARENT) == 0 && dvp != dp) {
if (wantparent)
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(dvp, 0);
- Further simplify lookup; Force all filesystems to relock in the DOTDOT case. There are bugs in some which didn't unlock in the ISDOTDOT case to begin with that need to be addressed seperately. This simplifies things anyway. - Fix relookup() to prevent it from vrele()'ing the dvp while the vp is locked. Catch up to other lookup changes. Sponsored by: Isilon Systems, Inc. Reported by: Peter Wemm
2005-04-13 10:57:13 +00:00
else
vput(dvp);
} else if (!wantparent)
vrele(dvp);
/*
* Check for symbolic link
*/
KASSERT(dp->v_type != VLNK || !(cnp->cn_flags & FOLLOW),
("relookup: symlink found.\n"));
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
/* ASSERT(dvp == ndp->ni_startdir) */
if (cnp->cn_flags & SAVESTART)
VREF(dvp);
This is the kernel Lite/2 commit. There are some requisite userland changes, so don't expect to be able to run the kernel as-is (very well) without the appropriate Lite/2 userland changes. The system boots and can mount UFS filesystems. Untested: ext2fs, msdosfs, NFS Known problems: Incorrect Berkeley ID strings in some files. Mount_std mounts will not work until the getfsent library routine is changed. Reviewed by: various people Submitted by: Jeffery Hsu <hsu@freebsd.org>
1997-02-10 02:22:35 +00:00
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
if ((cnp->cn_flags & LOCKLEAF) == 0)
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(dp, 0);
Moved the "relookup" routine into vfs_lookup.c from ufs/ufs/ufs_vnops.c. Several FS's use this, so it doesn't belong in ufs. (unionfs, msdosfs and ufs)
1994-09-27 20:33:41 +00:00
return (0);
bad:
vput(dp);
*vpp = NULL;
return (error);
}
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
Change the cap_rights_t type from uint64_t to a structure that we can extend in the future in a backward compatible (API and ABI) way. The cap_rights_t represents capability rights. We used to use one bit to represent one right, but we are running out of spare bits. Currently the new structure provides place for 114 rights (so 50 more than the previous cap_rights_t), but it is possible to grow the structure to hold at least 285 rights, although we can make it even larger if 285 rights won't be enough. The structure definition looks like this: struct cap_rights { uint64_t cr_rights[CAP_RIGHTS_VERSION + 2]; }; The initial CAP_RIGHTS_VERSION is 0. The top two bits in the first element of the cr_rights[] array contain total number of elements in the array - 2. This means if those two bits are equal to 0, we have 2 array elements. The top two bits in all remaining array elements should be 0. The next five bits in all array elements contain array index. Only one bit is used and bit position in this five-bits range defines array index. This means there can be at most five array elements in the future. To define new right the CAPRIGHT() macro must be used. The macro takes two arguments - an array index and a bit to set, eg. #define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL) We still support aliases that combine few rights, but the rights have to belong to the same array element, eg: #define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL) #define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL) #define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP) There is new API to manage the new cap_rights_t structure: cap_rights_t *cap_rights_init(cap_rights_t *rights, ...); void cap_rights_set(cap_rights_t *rights, ...); void cap_rights_clear(cap_rights_t *rights, ...); bool cap_rights_is_set(const cap_rights_t *rights, ...); bool cap_rights_is_valid(const cap_rights_t *rights); void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src); void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src); bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little); Capability rights to the cap_rights_init(), cap_rights_set(), cap_rights_clear() and cap_rights_is_set() functions are provided by separating them with commas, eg: cap_rights_t rights; cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT); There is no need to terminate the list of rights, as those functions are actually macros that take care of the termination, eg: #define cap_rights_set(rights, ...) \ __cap_rights_set((rights), __VA_ARGS__, 0ULL) void __cap_rights_set(cap_rights_t *rights, ...); Thanks to using one bit as an array index we can assert in those functions that there are no two rights belonging to different array elements provided together. For example this is illegal and will be detected, because CAP_LOOKUP belongs to element 0 and CAP_PDKILL to element 1: cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL); Providing several rights that belongs to the same array's element this way is correct, but is not advised. It should only be used for aliases definition. This commit also breaks compatibility with some existing Capsicum system calls, but I see no other way to do that. This should be fine as Capsicum is still experimental and this change is not going to 9.x. Sponsored by: The FreeBSD Foundation
2013-09-05 00:09:56 +00:00
void
NDINIT_ALL(struct nameidata *ndp, u_long op, u_long flags, enum uio_seg segflg,
const char *namep, int dirfd, struct vnode *startdir, cap_rights_t *rightsp,
struct thread *td)
{
ndp->ni_cnd.cn_nameiop = op;
ndp->ni_cnd.cn_flags = flags;
ndp->ni_segflg = segflg;
ndp->ni_dirp = namep;
ndp->ni_dirfd = dirfd;
ndp->ni_startdir = startdir;
ndp->ni_strictrelative = 0;
if (rightsp != NULL)
ndp->ni_rightsneeded = *rightsp;
else
cap_rights_init(&ndp->ni_rightsneeded);
filecaps_init(&ndp->ni_filecaps);
ndp->ni_cnd.cn_thread = td;
}
- Move NDFREE() from vfs_subr to vfs_lookup where namei() is.
2005-04-05 08:58:49 +00:00
/*
* Free data allocated by namei(); see namei(9) for details.
*/
void
Remove register, use ANSI function headers.
2006-08-05 21:40:59 +00:00
NDFREE(struct nameidata *ndp, const u_int flags)
- Move NDFREE() from vfs_subr to vfs_lookup where namei() is.
2005-04-05 08:58:49 +00:00
{
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
int unlock_dvp;
int unlock_vp;
unlock_dvp = 0;
unlock_vp = 0;
- Move NDFREE() from vfs_subr to vfs_lookup where namei() is.
2005-04-05 08:58:49 +00:00
if (!(flags & NDF_NO_FREE_PNBUF) &&
(ndp->ni_cnd.cn_flags & HASBUF)) {
uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
ndp->ni_cnd.cn_flags &= ~HASBUF;
}
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
if (!(flags & NDF_NO_VP_UNLOCK) &&
(ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp)
unlock_vp = 1;
if (!(flags & NDF_NO_VP_RELE) && ndp->ni_vp) {
if (unlock_vp) {
vput(ndp->ni_vp);
unlock_vp = 0;
} else
vrele(ndp->ni_vp);
ndp->ni_vp = NULL;
}
if (unlock_vp)
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(ndp->ni_vp, 0);
- Move NDFREE() from vfs_subr to vfs_lookup where namei() is.
2005-04-05 08:58:49 +00:00
if (!(flags & NDF_NO_DVP_UNLOCK) &&
(ndp->ni_cnd.cn_flags & LOCKPARENT) &&
ndp->ni_dvp != ndp->ni_vp)
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
unlock_dvp = 1;
- Move NDFREE() from vfs_subr to vfs_lookup where namei() is.
2005-04-05 08:58:49 +00:00
if (!(flags & NDF_NO_DVP_RELE) &&
(ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) {
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
if (unlock_dvp) {
vput(ndp->ni_dvp);
unlock_dvp = 0;
} else
vrele(ndp->ni_dvp);
- Move NDFREE() from vfs_subr to vfs_lookup where namei() is.
2005-04-05 08:58:49 +00:00
ndp->ni_dvp = NULL;
}
- If we vrele() a dvp while the child is locked we can potentially deadlock when vrele() acquires the directory lock in the wrong order. Fix this via the following changes: - Keep the directory locked after VOP_LOOKUP() until we've determined what we're going to do with the child. This allows us to remove the complicated post LOOKUP code which determins whether we should lock or unlock the parent. This means we may have to vput() in the appropriate cases later, rather than doing an unsafe vrele. - in NDFREE() keep two flags to indicate whether we need to unlock vp or dvp. This allows us to vput rather than vrele in the appropriate cases without rechecking the flags. Move the code to handle dvp after we handle vp. - Remove some dead code from namei() that was the result of changes to VFS_LOCK_GIANT(). Sponsored by: Isilon Systems, Inc.
2005-04-09 11:53:16 +00:00
if (unlock_dvp)
VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in conjuction with 'thread' argument passing which is always curthread. Remove the unuseful extra-argument and pass explicitly curthread to lower layer functions, when necessary. KPI results broken by this change, which should affect several ports, so version bumping and manpage update will be further committed. Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
2008-01-13 14:44:15 +00:00
VOP_UNLOCK(ndp->ni_dvp, 0);
- Move NDFREE() from vfs_subr to vfs_lookup where namei() is.
2005-04-05 08:58:49 +00:00
if (!(flags & NDF_NO_STARTDIR_RELE) &&
(ndp->ni_cnd.cn_flags & SAVESTART)) {
vrele(ndp->ni_startdir);
ndp->ni_startdir = NULL;
}
}
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
/*
* Determine if there is a suitable alternate filename under the specified
* prefix for the specified path. If the create flag is set, then the
* alternate prefix will be used so long as the parent directory exists.
sys/kern: spelling fixes in comments. No functional change.
2016-04-29 22:15:33 +00:00
* This is used by the various compatibility ABIs so that Linux binaries prefer
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
* files under /compat/linux for example. The chosen path (whether under
* the prefix or under /) is returned in a kernel malloc'd buffer pointed
* to by pathbuf. The caller is responsible for free'ing the buffer from
* the M_TEMP bucket if one is returned.
*/
int
Implement the linux syscalls openat, mkdirat, mknodat, fchownat, futimesat, fstatat, unlinkat, renameat, linkat, symlinkat, readlinkat, fchmodat, faccessat. Submitted by: rdivacky Sponsored by: Google Summer of Code 2007 Tested by: pho
2008-04-08 09:45:49 +00:00
kern_alternate_path(struct thread *td, const char *prefix, const char *path,
enum uio_seg pathseg, char **pathbuf, int create, int dirfd)
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
{
struct nameidata nd, ndroot;
char *ptr, *buf, *cp;
size_t len, sz;
int error;
buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
*pathbuf = buf;
/* Copy the prefix into the new pathname as a starting point. */
len = strlcpy(buf, prefix, MAXPATHLEN);
if (len >= MAXPATHLEN) {
*pathbuf = NULL;
free(buf, M_TEMP);
return (EINVAL);
}
sz = MAXPATHLEN - len;
ptr = buf + len;
/* Append the filename to the prefix. */
if (pathseg == UIO_SYSSPACE)
error = copystr(path, ptr, sz, &len);
else
error = copyinstr(path, ptr, sz, &len);
if (error) {
*pathbuf = NULL;
free(buf, M_TEMP);
return (error);
}
/* Only use a prefix with absolute pathnames. */
if (*ptr != '/') {
error = EINVAL;
goto keeporig;
}
Implement the linux syscalls openat, mkdirat, mknodat, fchownat, futimesat, fstatat, unlinkat, renameat, linkat, symlinkat, readlinkat, fchmodat, faccessat. Submitted by: rdivacky Sponsored by: Google Summer of Code 2007 Tested by: pho
2008-04-08 09:45:49 +00:00
if (dirfd != AT_FDCWD) {
/*
* We want the original because the "prefix" is
* included in the already opened dirfd.
*/
bcopy(ptr, buf, len);
return (0);
}
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
/*
* We know that there is a / somewhere in this pathname.
* Search backwards for it, to find the file's parent dir
* to see if it exists in the alternate tree. If it does,
* and we want to create a file (cflag is set). We don't
* need to worry about the root comparison in this case.
*/
if (create) {
for (cp = &ptr[len] - 1; *cp != '/'; cp--);
*cp = '\0';
Remove the support for using non-mpsafe filesystem modules. In particular, do not lock Giant conditionally when calling into the filesystem module, remove the VFS_LOCK_GIANT() and related macros. Stop handling buffers belonging to non-mpsafe filesystems. The VFS_VERSION is bumped to indicate the interface change which does not result in the interface signatures changes. Conducted and reviewed by: attilio Tested by: pho
2012-10-22 17:50:54 +00:00
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td);
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
error = namei(&nd);
*cp = '/';
if (error != 0)
Use correct VFS locking rather than unconditionally grabbing Giant around namei() calls in kern_alternate_path(). Reviewed by: csjp MFC after: 1 week
2005-09-21 19:49:42 +00:00
goto keeporig;
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
} else {
Remove the support for using non-mpsafe filesystem modules. In particular, do not lock Giant conditionally when calling into the filesystem module, remove the VFS_LOCK_GIANT() and related macros. Stop handling buffers belonging to non-mpsafe filesystems. The VFS_VERSION is bumped to indicate the interface change which does not result in the interface signatures changes. Conducted and reviewed by: attilio Tested by: pho
2012-10-22 17:50:54 +00:00
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td);
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
error = namei(&nd);
if (error != 0)
Use correct VFS locking rather than unconditionally grabbing Giant around namei() calls in kern_alternate_path(). Reviewed by: csjp MFC after: 1 week
2005-09-21 19:49:42 +00:00
goto keeporig;
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
/*
* We now compare the vnode of the prefix to the one
* vnode asked. If they resolve to be the same, then we
* ignore the match so that the real root gets used.
* This avoids the problem of traversing "../.." to find the
* root directory and never finding it, because "/" resolves
* to the emulation root directory. This is expensive :-(
*/
Remove the support for using non-mpsafe filesystem modules. In particular, do not lock Giant conditionally when calling into the filesystem module, remove the VFS_LOCK_GIANT() and related macros. Stop handling buffers belonging to non-mpsafe filesystems. The VFS_VERSION is bumped to indicate the interface change which does not result in the interface signatures changes. Conducted and reviewed by: attilio Tested by: pho
2012-10-22 17:50:54 +00:00
NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, prefix,
Use correct VFS locking rather than unconditionally grabbing Giant around namei() calls in kern_alternate_path(). Reviewed by: csjp MFC after: 1 week
2005-09-21 19:49:42 +00:00
td);
- Tweak kern_msgctl() to return a copy of the requested message queue id structure in the struct pointed to by the 3rd argument for IPC_STAT and get rid of the 4th argument. The old way returned a pointer into the kernel array that the calling function would then access afterwards without holding the appropriate locks and doing non-lock-safe things like copyout() with the data anyways. This change removes that unsafeness and resulting race conditions as well as simplifying the interface. - Implement kern_foo wrappers for stat(), lstat(), fstat(), statfs(), fstatfs(), and fhstatfs(). Use these wrappers to cut out a lot of code duplication for freebsd4 and netbsd compatability system calls. - Add a new lookup function kern_alternate_path() that looks up a filename under an alternate prefix and determines which filename should be used. This is basically a more general version of linux_emul_convpath() that can be shared by all the ABIs thus allowing for further reduction of code duplication.
2005-02-07 18:44:55 +00:00
/* We shouldn't ever get an error from this namei(). */
error = namei(&ndroot);
if (error == 0) {
if (nd.ni_vp == ndroot.ni_vp)
error = ENOENT;
NDFREE(&ndroot, NDF_ONLY_PNBUF);
vrele(ndroot.ni_vp);
}
}
NDFREE(&nd, NDF_ONLY_PNBUF);
vrele(nd.ni_vp);
keeporig:
/* If there was an error, use the original path name. */
if (error)
bcopy(ptr, buf, len);
return (error);
}
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