Commit Graph

174 Commits

Author SHA1 Message Date
Konstantin Belousov
140dedb81c The r241025 fixed the case when a binary, executed from nullfs mount,
was still possible to open for write from the lower filesystem.  There
is a symmetric situation where the binary could already has file
descriptors opened for write, but it can be executed from the nullfs
overlay.

Handle the issue by passing one v_writecount reference to the lower
vnode if nullfs vnode has non-zero v_writecount.  Note that only one
write reference can be donated, since nullfs only keeps one use
reference on the lower vnode.  Always use the lower vnode v_writecount
for the checks.

Introduce the VOP_GET_WRITECOUNT to read v_writecount, which is
currently always bypassed to the lower vnode, and VOP_ADD_WRITECOUNT
to manipulate the v_writecount value, which manages a single bypass
reference to the lower vnode.  Caling the VOPs instead of directly
accessing v_writecount provide the fix described in the previous
paragraph.

Tested by:	pho
MFC after:	3 weeks
2012-11-02 13:56:36 +00:00
Konstantin Belousov
5050aa86cf 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
Konstantin Belousov
877d24ac8a Fix the mis-handling of the VV_TEXT on the nullfs vnodes.
If you have a binary on a filesystem which is also mounted over by
nullfs, you could execute the binary from the lower filesystem, or
from the nullfs mount. When executed from lower filesystem, the lower
vnode gets VV_TEXT flag set, and the file cannot be modified while the
binary is active. But, if executed as the nullfs alias, only the
nullfs vnode gets VV_TEXT set, and you still can open the lower vnode
for write.

Add a set of VOPs for the VV_TEXT query, set and clear operations,
which are correctly bypassed to lower vnode.

Tested by:	pho (previous version)
MFC after:	2 weeks
2012-09-28 11:25:02 +00:00
Kirk McKusick
75c898f2a4 When synchronously syncing a device (MNT_WAIT), wait for buffers
to become available. Otherwise we may excessively spin and fail
with ``fsync: giving up on dirty''.

Reviewed by: kib
Tested by:   Peter Holm
MFC after:   1 week
2012-06-09 22:26:53 +00:00
Gleb Kurtsou
ac13a90c4b Skip directory entries with zero inode number during traversal.
Entries with zero inode number are considered placeholders by libc and
UFS.  Fix remaining uses of VOP_READDIR in kernel: vop_stdvptocnp,
unionfs.

Sponsored by:	Google Summer of Code 2011
2012-05-16 10:44:09 +00:00
Kirk McKusick
71469bb38f Replace the MNT_VNODE_FOREACH interface with MNT_VNODE_FOREACH_ALL.
The primary changes are that the user of the interface no longer
needs to manage the mount-mutex locking and that the vnode that
is returned has its mutex locked (thus avoiding the need to check
to see if its is DOOMED or other possible end of life senarios).

To minimize compatibility issues for third-party developers, the
old MNT_VNODE_FOREACH interface will remain available so that this
change can be MFC'ed to 9. Following the MFC to 9, MNT_VNODE_FOREACH
will be removed in head.

The reason for this update is to prepare for the addition of the
MNT_VNODE_FOREACH_ACTIVE interface that will loop over just the
active vnodes associated with a mount point (typically less than
1% of the vnodes associated with the mount point).

Reviewed by: kib
Tested by:   Peter Holm
MFC after:   2 weeks
2012-04-17 16:28:22 +00:00
Mikolaj Golub
c7e41c8b50 Introduce VOP_UNP_BIND(), VOP_UNP_CONNECT(), and VOP_UNP_DETACH()
operations for setting and accessing vnode's v_socket field.

The operations are necessary to implement proper unix socket handling
on layered file systems like nullfs(5).

This change fixes the long standing issue with nullfs(5) being in that
unix sockets did not work between lower and upper layers: if we bound
to a socket on the lower layer we could connect only to the lower
path; if we bound to the upper layer we could connect only to the
upper path. The new behavior is one can connect to both the lower and
the upper paths regardless what layer path one binds to.

PR:		kern/51583, kern/159663
Suggested by:	kib
Reviewed by:	arch
MFC after:	2 weeks
2012-02-29 21:38:31 +00:00
Konstantin Belousov
f82360acf2 Existing VOP_VPTOCNP() interface has a fatal flow that is critical for
nullfs.  The problem is that resulting vnode is only required to be
held on return from the successfull call to vop, instead of being
referenced.

Nullfs VOP_INACTIVE() method reclaims the vnode, which in combination
with the VOP_VPTOCNP() interface means that the directory vnode
returned from VOP_VPTOCNP() is reclaimed in advance, causing
vn_fullpath() to error with EBADF or like.

Change the interface for VOP_VPTOCNP(), now the dvp must be
referenced. Convert all in-tree implementations of VOP_VPTOCNP(),
which is trivial, because vhold(9) and vref(9) are similar in the
locking prerequisites. Out-of-tree fs implementation of VOP_VPTOCNP(),
if any, should have no trouble with the fix.

Tested by:	pho
Reviewed by:	mckusick
MFC after:	3 weeks (subject of re approval)
2011-11-19 07:50:49 +00:00
John Baldwin
936c09ac0f Add the posix_fadvise(2) system call. It is somewhat similar to
madvise(2) except that it operates on a file descriptor instead of a
memory region.  It is currently only supported on regular files.

Just as with madvise(2), the advice given to posix_fadvise(2) can be
divided into two types.  The first type provide hints about data access
patterns and are used in the file read and write routines to modify the
I/O flags passed down to VOP_READ() and VOP_WRITE().  These modes are
thus filesystem independent.  Note that to ease implementation (and
since this API is only advisory anyway), only a single non-normal
range is allowed per file descriptor.

The second type of hints are used to hint to the OS that data will or
will not be used.  These hints are implemented via a new VOP_ADVISE().
A default implementation is provided which does nothing for the WILLNEED
request and attempts to move any clean pages to the cache page queue for
the DONTNEED request.  This latter case required two other changes.
First, a new V_CLEANONLY flag was added to vinvalbuf().  This requests
vinvalbuf() to only flush clean buffers for the vnode from the buffer
cache and to not remove any backing pages from the vnode.  This is
used to ensure clean pages are not wired into the buffer cache before
attempting to move them to the cache page queue.  The second change adds
a new vm_object_page_cache() method.  This method is somewhat similar to
vm_object_page_remove() except that instead of freeing each page in the
specified range, it attempts to move clean pages to the cache queue if
possible.

To preserve the ABI of struct file, the f_cdevpriv pointer is now reused
in a union to point to the currently active advice region if one is
present for regular files.

Reviewed by:	jilles, kib, arch@
Approved by:	re (kib)
MFC after:	1 month
2011-11-04 04:02:50 +00:00
Rick Macklem
694a586a43 Add a lock flags argument to the VFS_FHTOVP() file system
method, so that callers can indicate the minimum vnode
locking requirement. This will allow some file systems to choose
to return a LK_SHARED locked vnode when LK_SHARED is specified
for the flags argument. This patch only adds the flag. It
does not change any file system to use it and all callers
specify LK_EXCLUSIVE, so file system semantics are not changed.

Reviewed by:	kib
2011-05-22 01:07:54 +00:00
Matthew D Fleming
1ce4508f6d Allow VOP_ALLOCATE to be iterative, and have kern_posix_fallocate(9)
drive looping and potentially yielding.

Requested by:	kib
2011-04-19 16:36:24 +00:00
Matthew D Fleming
d91f88f7f3 Add the posix_fallocate(2) syscall. The default implementation in
vop_stdallocate() is filesystem agnostic and will run as slow as a
read/write loop in userspace; however, it serves to correctly
implement the functionality for filesystems that do not implement a
VOP_ALLOCATE.

Note that __FreeBSD_version was already bumped today to 900036 for any
ports which would like to use this function.

Also reserve space in the syscall table for posix_fadvise(2).

Reviewed by:	-arch (previous version)
2011-04-18 16:32:22 +00:00
Brian Somers
c2d844d814 If we read zero bytes from the directory, early out with ENOENT
rather than forging ahead and interpreting garbage buffer content
and dirent structures.

This change backs out r211684 which was essentially a no-op.

MFC after:	1 week
2010-08-25 18:09:51 +00:00
Brian Somers
90db41b62b uio_resid isn't updated by VOP_READDIR for nfs filesystems. Use
the uio_offset adjustment instead to calculate a correct *len.

Without this change, we run off the end of the directory data
we're reading and panic horribly for nfs filesystems.

MFC after:	1 week
2010-08-23 05:33:31 +00:00
Zachary Loafman
7fd32ea923 Add VOP_ADVLOCKPURGE so that the file system is called when purging
locks (in the case where the VFS impl isn't using lf_*)

Submitted by:       Matthew Fleming <matthew.fleming@isilon.com>
Reviewed by:        zml, dfr
2010-05-12 21:24:46 +00:00
Konstantin Belousov
0bc7bd67ca Supply default implementation of VOP_RENAME() that does neccessary
unlocks and unreferences for argument vnodes, as expected by
kern_renameat(9), and returns EOPNOTSUPP. This fixes locks and
reference leaks when rename is attempted on fs that does not
implement rename.

PR:	kern/107439
Based on submission by:	Mikolaj Golub <to.my.trociny gmail com>
Tested by:	Mikolaj Golub
MFC after:	1 week
2010-04-02 14:03:43 +00:00
Pawel Jakub Dawidek
e15d7a0b4c Use vput() instead of VOP_UNLOCK()+vrele(). The comment here is out-dated,
we no longer pass thread pointer to VOP_UNLOCK().
2010-02-18 22:14:44 +00:00
Edward Tomasz Napierala
23e62e7654 Revert r198873. Having different VAPPEND semantics for VOP_ACCESS(9)
and VOP_ACCESSX(9) is not a good idea.
2009-11-11 13:49:22 +00:00
Edward Tomasz Napierala
597954c813 While VAPPEND without VWRITE makes sense for VOP_ACCESSX(9) (e.g. to check
for the permission to create subdirectory (ACE4_ADD_SUBDIRECTORY)), it doesn't
really make sense for VOP_ACCESS(9).  Also, many VOP_ACCESS(9) implementations
don't expect that.  Make sure we don't confuse them.
2009-11-04 06:47:14 +00:00
Edward Tomasz Napierala
2c29cfa083 Provide default implementation for VOP_ACCESS(9), so that filesystems which
want to provide VOP_ACCESSX(9) don't have to implement both.  Note that
this commit makes implementation of either of these two mandatory.

Reviewed by:	kib
2009-10-01 17:22:03 +00:00
Konstantin Belousov
c808c9632d Add explicit struct ucred * argument for VOP_VPTOCNP, to be used by
vn_open_cred in default implementation. Valid struct ucred is needed for
audit and MAC, and curthread credentials may be wrong.

This further requires modifying the interface of vn_fullpath(9), but it
is out of scope of this change.

Reviewed by:	rwatson
2009-06-21 19:21:01 +00:00
Konstantin Belousov
e0c161b89c Add another flags argument to vn_open_cred. Use it to specify that some
vn_open_cred invocations shall not audit namei path.

In particular, specify VN_OPEN_NOAUDIT for dotdot lookup performed by
default implementation of vop_vptocnp, and for the open done for core
file. vn_fullpath is called from the audit code, and vn_open there need
to disable audit to avoid infinite recursion. Core file is created on
return to user mode, that, in particular, happens during syscall return.
The creation of the core file is audited by direct calls, and we do not
want to overwrite audit information for syscall.

Reported, reviewed and tested by: rwatson
2009-06-21 13:41:32 +00:00
Robert Watson
af4656042e Add mac_framework.h include missed when MAC code was (presumably) copied
from another file.
2009-06-05 14:23:24 +00:00
Edward Tomasz Napierala
c97fcdba57 Add VOP_ACCESSX, which can be used to query for newly added V*
permissions, such as VWRITE_ACL.  For a filsystems that don't
implement it, there is a default implementation, which works
as a wrapper around VOP_ACCESS.

Reviewed by:	rwatson@
2009-05-30 13:59:05 +00:00
Attilio Rao
dfd233edd5 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
Robert Watson
885868cd8f Remove VOP_LEASE and supporting functions. This hasn't been used since
the removal of NQNFS, but was left in in case it was required for NFSv4.
Since our new NFSv4 client and server can't use it for their
requirements, GC the old mechanism, as well as other unused lease-
related code and interfaces.

Due to its impact on kernel programming and binary interfaces, this
change should not be MFC'd.

Proposed by:    jeff
Reviewed by:    jeff
Discussed with: rmacklem, zach loafman @ isilon
2009-04-10 10:52:19 +00:00
Joe Marcus Clarke
f8ecc40737 Add a default implementation for VOP_VPTOCNP(9) which scans the parent
directory of a vnode to find a dirent with a matching file number.  The
name from that dirent is then used to provide the component name.

Note: if the initial vnode argument is not a directory itself, then
the default VOP_VPTOCNP(9) implementation still returns ENOENT.

Reviewed by:	kib
Approved by:	kib
Tested by:	pho
2009-03-08 19:05:53 +00:00
Konstantin Belousov
125dcf8c7d Extract the no_poll() and vop_nopoll() code into the common routine
poll_no_poll().
Return a poll_no_poll() result from devfs_poll_f() when
filedescriptor does not reference the live cdev, instead of ENXIO.

Noted and tested by:	hps
MFC after:	1 week
2009-03-06 15:35:37 +00:00
Joe Marcus Clarke
b9022449b3 Add a new VOP, VOP_VPTOCNP, which translates a vnode to its component name
on a best-effort basis.  Teach vn_fullpath to use this new VOP if a
regular VFS cache lookup fails.  This VOP is designed to supplement the
VFS cache to provide a better chance that a vnode-to-name lookup will
succeed.

Currently, an implementation for devfs is being committed.  The default
implementation is to return ENOENT.

A big thanks to kib for the mentorship on this, and to pho for running it
through his stress test suite.

Reviewed by:	arch
Approved by:	kib
2008-12-12 00:57:38 +00:00
Attilio Rao
0359a12ead Decontextualize the couplet VOP_GETATTR / VOP_SETATTR as the passed thread
was always curthread and totally unuseful.

Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
2008-08-28 15:23:18 +00:00
Konstantin Belousov
eab626f110 Move the head of byte-level advisory lock list from the
filesystem-specific vnode data to the struct vnode. Provide the
default implementation for the vop_advlock and vop_advlockasync.
Purge the locks on the vnode reclaim by using the lf_purgelocks().
The default implementation is augmented for the nfs and smbfs.
In the nfs_advlock, push the Giant inside the nfs_dolock.

Before the change, the vop_advlock and vop_advlockasync have taken the
unlocked vnode and dereferenced the fs-private inode data, racing with
with the vnode reclamation due to forced unmount. Now, the vop_getattr
under the shared vnode lock is used to obtain the inode size, and
later, in the lf_advlockasync, after locking the vnode interlock, the
VI_DOOMED flag is checked to prevent an operation on the doomed vnode.

The implementation of the lf_purgelocks() is submitted by dfr.

Reported by:	kris
Tested by:	kris, pho
Discussed with:	jeff, dfr
MFC after:	2 weeks
2008-04-16 11:33:32 +00:00
Jeff Roberson
698b1a6643 - Complete part of the unfinished bufobj work by consistently using
BO_LOCK/UNLOCK/MTX when manipulating the bufobj.
 - Create a new lock in the bufobj to lock bufobj fields independently.
   This leaves the vnode interlock as an 'identity' lock while the bufobj
   is an io lock.  The bufobj lock is ordered before the vnode interlock
   and also before the mnt ilock.
 - Exploit this new lock order to simplify softdep_check_suspend().
 - A few sync related functions are marked with a new XXX to note that
   we may not properly interlock against a non-zero bv_cnt when
   attempting to sync all vnodes on a mountlist.  I do not believe this
   race is important.  If I'm wrong this will make these locations easier
   to find.

Reviewed by:	kib (earlier diff)
Tested by:	kris, pho (earlier diff)
2008-03-22 09:15:16 +00:00
Attilio Rao
81c794f998 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
Attilio Rao
24463dbbee - Introduce lockmgr_args() in the lockmgr space. This function performs
the same operation of lockmgr() but accepting a custom wmesg, prio and
  timo for the particular lock instance, overriding default values
  lkp->lk_wmesg, lkp->lk_prio and lkp->lk_timo.
- Use lockmgr_args() in order to implement BUF_TIMELOCK()
- Cleanup BUF_LOCK()
- Remove LK_INTERNAL as it is nomore used in the lockmgr namespace

Tested by:	Andrea Barberio <insomniac at slackware dot it>
2008-02-15 21:04:36 +00:00
Attilio Rao
0e9eb108f0 Cleanup lockmgr interface and exported KPI:
- Remove the "thread" argument from the lockmgr() function as it is
  always curthread now
- Axe lockcount() function as it is no longer used
- Axe LOCKMGR_ASSERT() as it is bogus really and no currently used.
  Hopefully this will be soonly replaced by something suitable for it.
- Remove the prototype for dumplockinfo() as the function is no longer
  present

Addictionally:
- Introduce a KASSERT() in lockstatus() in order to let it accept only
  curthread or NULL as they should only be passed
- Do a little bit of style(9) cleanup on lockmgr.h

KPI results heavilly broken by this change, so manpages and
FreeBSD_version will be modified accordingly by further commits.

Tested by: matteo
2008-01-24 12:34:30 +00:00
Attilio Rao
22db15c06f 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
Konstantin Belousov
d413d21071 Since renaming of vop_lock to _vop_lock, pre- and post-condition
function calls are no more generated for vop_lock.
Rename _vop_lock to vop_lock1 to satisfy tools/vnode_if.awk assumption
about vop naming conventions. This restores pre/post-condition calls.
2007-05-18 13:02:13 +00:00
Pawel Jakub Dawidek
2c7b0f41ec Remove VFS_VPTOFH entirely. API is already broken and it is good time to
do it.

Suggested by:	rwatson
2007-02-16 17:32:41 +00:00
Pawel Jakub Dawidek
10bcafe9ab Move vnode-to-file-handle translation from vfs_vptofh to vop_vptofh method.
This way we may support multiple structures in v_data vnode field within
one file system without using black magic.

Vnode-to-file-handle should be VOP in the first place, but was made VFS
operation to keep interface as compatible as possible with SUN's VFS.
BTW. Now Solaris also implements vnode-to-file-handle as VOP operation.

VFS_VPTOFH() was left for API backward compatibility, but is marked for
removal before 8.0-RELEASE.

Approved by:	mckusick
Discussed with:	many (on IRC)
Tested with:	ufs, msdosfs, cd9660, nullfs and zfs
2007-02-15 22:08:35 +00:00
Kip Macy
2f6a774be4 change vop_lock handling to allowing tracking of callers' file and line for
acquisition of lockmgr locks

Approved by: scottl (standing in for mentor rwatson)
2006-11-13 05:51:22 +00:00
Tor Egge
60b0b1aa18 Don't try to obtain a reference to a nonexisting (NULL) mount structure in
default VOP_GETWRITEMOUNT().
2006-09-20 00:27:02 +00:00
Jeff Roberson
c5fcce21c5 - GETWRITEMOUNT now returns a referenced mountpoint to prevent its
identity from changing.  This is possible now that mounts are not freed.

Discussed with:	tegge
Tested by:	kris
Sponsored by:	Isilon Systems, Inc.
2006-03-31 03:52:24 +00:00
Jeff Roberson
608c95d341 - Add a comment warning about an anomalous condition where we VOP_UNLOCK
and then vrele rather than vput because we would like to VOP_UNLOCK with
   a specific thread.
2006-01-30 08:21:23 +00:00
Tor Egge
82be0a5a24 Add marker vnodes to ensure that all vnodes associated with the mount point are
iterated over when using MNT_VNODE_FOREACH.

Reviewed by:	truckman
2006-01-09 20:42:19 +00:00
Dag-Erling Smørgrav
0430a5e289 Eradicate caddr_t from the VFS API. 2005-12-14 00:49:52 +00:00
Poul-Henning Kamp
a07b0febaa In vop_stdpathconf(ap) also default for _PC_NAME_MAX and _PC_PATH_MAX. 2005-08-17 06:59:23 +00:00
Jeff Roberson
e8ddb61d38 - Replace the series of DEBUG_LOCKS hacks which tried to save the vn_lock
caller by saving the stack of the last locker/unlocker in lockmgr.  We
   also put the stack in KTR at the moment.

Contributed by:		Antoine Brodin <antoine.brodin@laposte.net>
2005-08-03 04:48:22 +00:00
Jeff Roberson
7a06fe49dc - Add and enhance asserts related to the wrong bufobj panic.
Sponsored by:	Isilon Systems, Inc.
Approved by:	re (blanket vfs)
2005-06-14 20:32:27 +00:00
Suleiman Souhlal
679985d03a Allow EVFILT_VNODE events to work on every filesystem type, not just
UFS by:
- Making the pre and post hooks for the VOP functions work even when
DEBUG_VFS_LOCKS is not defined.
- Moving the KNOTE activations into the corresponding VOP hooks.
- Creating a MNTK_NOKNOTE flag for the mnt_kern_flag field of struct
mount that permits filesystems to disable the new behavior.
- Creating a default VOP_KQFILTER function: vfs_kqfilter()

My benchmarks have not revealed any performance degradation.

Reviewed by:	jeff, bde
Approved by:	rwatson, jmg (kqueue changes), grehan (mentor)
2005-06-09 20:20:31 +00:00
Jeff Roberson
5270a2dbe3 - Remove unnecessary spls. 2005-05-01 00:59:34 +00:00