pointer types, and remove a huge number of casts from code using it.
Change struct xfile xf_data to xun_data (ABI is still compatible).
If we need to add a #define for f_data and xf_data we can, but I don't
think it will be necessary. There are no operational changes in this
commit.
The leak in lseek was introduced in vfs_syscalls.c revision 1.218.
The leak in do_dup was introduced in kern_descrip.c revision 1.158.
Submitted by: iedowse
missed. This bug has been present since the vn_start_write() and
vn_finished_write() calls were first added in revision 1.159. When
the case is triggered, any attempts to create snapshots on the
filesystem will deadlock and also prevent further write activity
on that filesystem.
to conform to 1003.1-2001. Make it possible for applications to actually
tell whether or not asynchronous I/O is supported.
Since FreeBSD's aio implementation works on all descriptor types, don't
call down into file or vnode ops when [f]pathconf() is asked about
_PC_ASYNC_IO; this avoids the need for every file and vnode op to know about
it.
creation, deletion, and rename. There are one or two other stray
cases I'll catch in follow-up commits (such as unix domain socket
creation); this permits MAC policy modules to limit the ability to
perform these operations based on existing UNIX credential / vnode
attributes, extended attributes, and security labels. In the rename
case using MAC, we now have to lock the from directory and file
vnodes for the MAC check, but this is done only in the MAC case,
and the locks are immediately released so that the remainder of the
rename implementation remains the same. Because the create check
takes a vattr to know object type information, we now initialize
additional fields in the VATTR passed to VOP_SYMLINK() in the MAC
case.
Approved by: re
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
revision 1.218. This bug caused a "struct file" reference to be
leaked if VOP_ADVLOCK(), vn_start_write(), or mac_check_vnode_write()
failed during the open operation.
PR: kern/43739
Reported by: Arne Woerner <woerner@mediabase-gmbh.de>
point that instruments the creation of hard links. Policy implementations
to follow.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
wasn't doing. Rather than just lock and unlock the vnode around the call
to VOP_FSYNC(), implement rwatson's suggestion to lock the file vnode
in kern_link() before calling VOP_LINK(), since the other filesystems
also locked the file vnode right away in their link methods. Remove the
locking and and unlocking from the leaf filesystem link methods.
Reviewed by: rwatson, bde (except for the unionfs_link() changes)
Changed rename(2) to follow the letter of the POSIX spec. POSIX
requires rename() to have no effect if its args "resolve to the same
existing file". I think "file" can only reasonably be read as referring
to the inode, although the rationale and "resolve" seem to say that
sameness is at the level of (resolved) directory entries.
ext2fs_vnops.c, ufs_vnops.c:
Replaced code that gave the historical BSD behaviour of removing one
link name by checks that this code is now unreachable. This fixes
some races. All vnodes needed to be unlocked for the removal, and
locking at another level using something like IN_RENAME was not even
attempted, so it was possible for rename(x, y) to return with both x
and y removed even without any unlink(2) syscalls (one process can
remove x using rename(x, y) and another process can remove y using
rename(y, x)).
Prodded by: alfred
MFC after: 8 weeks
PR: 42617
a kernel-internal kern_*() version and a wrapper that is called via
the syscall vector table. For paths and structure pointers, the
internal version either takes a uio_seg parameter or requires the
caller to copyin() the data to kernel memory as appropiate. This
will permit emulation layers to use these syscalls without having
to copy out translated arguments to the stack gap.
Discussed on: -arch
Review/suggestions: bde, jhb, peter, marcel
for mac_check_vnode_{poll,read,stat,write}(). Pass in fp->f_cred
when calling these checks with a struct file available. Otherwise,
pass NOCRED. All currently MAC policies use active_cred, but
could now offer the cached credential semantic used for the base
system security model.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
mac_check_vnode_poll(), mac_check_vnode_read(), mac_check_vnode_write().
This improves the consistency with other existing vnode checks, and
allows policies to avoid implementing switch statements to determine
what operations they do and do not want to authorize.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
fo_read() and fo_write(): explicitly use the cred argument to fo_poll()
as "active_cred" using the passed file descriptor's f_cred reference
to provide access to the file credential. Add an active_cred
argument to fo_stat() so that implementers have access to the active
credential as well as the file credential. Generally modify callers
of fo_stat() to pass in td->td_ucred rather than fp->f_cred, which
was redundantly provided via the fp argument. This set of modifications
also permits threads to perform these operations on behalf of another
thread without modifying their credential.
Trickle this change down into fo_stat/poll() implementations:
- badfo_poll(), badfo_stat(): modify/add arguments.
- kqueue_poll(), kqueue_stat(): modify arguments.
- pipe_poll(), pipe_stat(): modify/add arguments, pass active_cred to
MAC checks rather than td->td_ucred.
- soo_poll(), soo_stat(): modify/add arguments, pass fp->f_cred rather
than cred to pru_sopoll() to maintain current semantics.
- sopoll(): moidfy arguments.
- vn_poll(), vn_statfile(): modify/add arguments, pass new arguments
to vn_stat(). Pass active_cred to MAC and fp->f_cred to VOP_POLL()
to maintian current semantics.
- vn_close(): rename cred to file_cred to reflect reality while I'm here.
- vn_stat(): Add active_cred and file_cred arguments to vn_stat()
and consumers so that this distinction is maintained at the VFS
as well as 'struct file' layer. Pass active_cred instead of
td->td_ucred to MAC and to VOP_GETATTR() to maintain current semantics.
- fifofs: modify the creation of a "filetemp" so that the file
credential is properly initialized and can be used in the socket
code if desired. Pass ap->a_td->td_ucred as the active
credential to soo_poll(). If we teach the vnop interface about
the distinction between file and active credentials, we would use
the active credential here.
Note that current inconsistent passing of active_cred vs. file_cred to
VOP's is maintained. It's not clear why GETATTR would be authorized
using active_cred while POLL would be authorized using file_cred at
the file system level.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
- 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
kernel access control.
Invoke appropriate MAC framework entry points to authorize readdir()
operations in the native ABI.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
kernel access control.
Instrument chdir() and chroot()-related system calls to invoke
appropriate MAC entry points to authorize the two operations.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
kernel access control.
Implement MAC framework access control entry points relating to
operations on mountpoints. Currently, this consists only of
access control on mountpoint listing using the various statfs()
variations. In the future, it might also be desirable to
implement checks on mount() and unmount().
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
open() of fhopen(). Currently this has no actual affect due to the
treatment of VAPPEND in vaccess() and vaccess_acl() as a subset of
VWRITE, but when MAC comes in, MAC will distinguish the two. Note:
if any file systems are cutting their own permission models, they
may wish to now take this into account.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
support creation times such as UFS2) to the value of the
modification time if the value of the modification time is older
than the current creation time. See utimes(2) for further details.
Sponsored by: DARPA & NAI Labs.
filedesc is already locked rather than having chroot() unlock the
filedesc so chroot_refuse_vdir_fds() can immediately relock it.
- Reorder chroot() a bitso that we do the namei lookup before checking
the process's struct filedesc. This closes at least one potential race
and allows us to only acquire the filedsec lock once in chroot().
- Push down Giant slightly into chroot().
The file vfs_conf.c which was dealing with root mounting has
been repo-copied into vfs_mount.c to preserve history.
This makes nmount related development easier, and help reducing
the size of vfs_syscalls.c, which is still an enormous file.
Reviewed by: rwatson
Repo-copy by: peter
direct calls for the two places where the kernel calls into soft
updates code. Set up the hooks in softdep_initialize() and NULL
them out in softdep_uninitialize(). This change allows soft updates
to function correctly when ufs is loaded as a module.
Reviewed by: mckusick
vnode in the case that the target exists and is the same vnode as
the parent (i.e. "mkdir ."). The namei() call does not leave the
vnode locked in this case even though you might expect it to.
This bug was mostly harmless in practice because unlocking an already
unlocked vnode currently does not trigger any panics or warnings.
Reviewed by: jeff
64-bit architectures that was introduced in the UFS2 code
merge two days ago. The stat structure change that caused
the problem was the addition of the file create time.
Submitted by: Bruce Evans <bde@zeta.org.au>
Sponsored by: DARPA & NAI Labs.
uio now that we don't use uiomove() anymore.
o Enforce stricter checks on the length of the iov's in
nmount(2) since we now malloc() them individually and
corrupted iov's could make the kernel crash in malloc()
with "kmem_map too small".
Reviewed by: phk
filesystem expands the inode to 256 bytes to make space for 64-bit
block pointers. It also adds a file-creation time field, an ability
to use jumbo blocks per inode to allow extent like pointer density,
and space for extended attributes (up to twice the filesystem block
size worth of attributes, e.g., on a 16K filesystem, there is space
for 32K of attributes). UFS2 fully supports and runs existing UFS1
filesystems. New filesystems built using newfs can be built in either
UFS1 or UFS2 format using the -O option. In this commit UFS1 is
the default format, so if you want to build UFS2 format filesystems,
you must specify -O 2. This default will be changed to UFS2 when
UFS2 proves itself to be stable. In this commit the boot code for
reading UFS2 filesystems is not compiled (see /sys/boot/common/ufsread.c)
as there is insufficient space in the boot block. Once the size of the
boot block is increased, this code can be defined.
Things to note: the definition of SBSIZE has changed to SBLOCKSIZE.
The header file <ufs/ufs/dinode.h> must be included before
<ufs/ffs/fs.h> so as to get the definitions of ufs2_daddr_t and
ufs_lbn_t.
Still TODO:
Verify that the first level bootstraps work for all the architectures.
Convert the utility ffsinfo to understand UFS2 and test growfs.
Add support for the extended attribute storage. Update soft updates
to ensure integrity of extended attribute storage. Switch the
current extended attribute interfaces to use the extended attribute
storage. Add the extent like functionality (framework is there,
but is currently never used).
Sponsored by: DARPA & NAI Labs.
Reviewed by: Poul-Henning Kamp <phk@freebsd.org>
a linked list. This is to allow the merging of the mount
options in the MNT_UPDATE case, as the current data structure
is unsuitable for this.
There are no functional differences in this commit.
Reviewed by: phk
in various extattr_*() calls to match the rest of the file. Originally,
these bits at the end looked more like style(9). This patch was submitted
by green by way of the TrustedBSD MAC tree, and I fixed a few problems
with it on the way through. Someone with more time on their hands should
convert the entire file to style(9); this commit is for diff reduction
purposes.
Submitted by: green
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
where some client operations might be unexpectedly cancelled during
an unsuccessful non-forced unmount attempt. This causes problems
for amd(8), because it periodically attempts a non-forced unmount
to check if the filesystem is still in use.
Fix this by adding a new mountpoint flag MNTK_UNMOUNTF that is set
only during the operation of a forced unmount. Use this instead of
MNTK_UNMOUNT to trigger the cancellation of hung NFS operations.
Also correct a problem where dounmount() might inadvertently clear
the MNTK_UNMOUNT flag.
Reported by: simokawa
MFC after: 1 week
behavior by default. Also, change the options line to reflect this.
If there are no problems reported this will become the only behavior and the
knob will be removed in a month or so.
Demanded by: obrien
separate strings instead of passing "foo=bar".
o Don't forget to clear the VMOUNT flag on the vnode when vfs_nmount()
fails because the fs doesn't implement VFS_NMOUNT (and in vfs_mount()
when the fs doesn't implement VFS_MOUNT) ; also decrement the vfs
refcount in the !MNT_UPDATE case.
general cleanup of the API. The entire API now consists of two functions
similar to the pre-KSE API. The suser() function takes a thread pointer
as its only argument. The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0. The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.
Discussed on: smp@
in vfs_mount(), in particular revisions 1.215, 1.227 and 1.240.
- flag2 is a low quality variable name, change it to kern_flag.
- strncpy NUL-terminates f_fstypename and f_mntonname since the strings
have length <= <buffer length> - 1, so the explicit NUL-termination is
bogus.
- M_ZERO'ing space for fstype and fspath is stupid since we never use the
space beyond the end of the string.
- Do various style(9) cleanups in both functions.
Submitted by: bde
Reviewed by: phk
- return error -> return (error);
- move a declaration to the top of the function.
- become bug for bug compatible with if (error) lines.
Submitted by: bde
new vfs_getopt()/vfs_copyopt() API. This is intended to be used
later, when there will be filesystems implementing the VFS_NMOUNT
operation. The mount(2) system call will disappear when all
filesystems will be converted to the new API. Documentation will
be committed in a while.
Reviewed by: phk
kern_linker.c and rev. 1.237 of vfs_syscalls.c since these are not the
source of the recent panics occuring around kldloading file system
support modules.
Requested by: rwatson
made aware in jail environments. Supposedly something is broken, so
this should be backed out until further investigation proves otherwise,
or a proper fix can be provided.
against users within a jail attempting to load kernel modules.
- Add a check of securelevel_gt() to vfs_mount() in order to chop some
low hanging fruit for the repair of securelevel checking of linking and
unlinking files from within jails. There is more to be done here.
Reviewed by: rwatson
The stat() and open() calls have been changed to make use of this new functionality. Using shared locks in
these cases is sufficient and can significantly reduce their latency if IO is pending to these vnodes. Also,
this reduces the number of exclusive locks that are floating around in the system, which helps reduce the
number of deadlocks that occur.
A new kernel option "LOOKUP_SHARED" has been added. It defaults to off so this patch can be turned on for
testing, and should eventually go away once it is proven to be stable. I have personally been running this
patch for over a year now, so it is believed to be fully stable.
Reviewed by: jake, obrien
Approved by: jake
to perform an ownership test in revoke(). This is also required for
MAC hooks so that the vnode lock is held during a call to the MAC
framework. Release the lock before calling VOP_REVOKE().
Discussed with: phk, mckusick
o Modify the system call syntax for extattr_{get,set}_{fd,file}() so
as not to use the scatter gather API (which appeared not to be used
by any consumers, and be less portable), rather, accepts 'data'
and 'nbytes' in the style of other simple read/write interfaces.
This changes the API and ABI.
o Modify system call semantics so that extattr_get_{fd,file}() return
a size_t. When performing a read, the number of bytes read will
be returned, unless the data pointer is NULL, in which case the
number of bytes of data are returned. This changes the API only.
o Modify the VOP_GETEXTATTR() vnode operation to accept a *size_t
argument so as to return the size, if desirable. If set to NULL,
the size will not be returned.
o Update various filesystems (pseodofs, ufs) to DTRT.
These changes should make extended attributes more useful and more
portable. More commits to rebuild the system call files, as well
as update userland utilities to follow.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
- Fix null-pointer dereference introduced when snapshotting
was introduced. This occured because unlike the previous code,
vn_start_write() doesn't always return a non-NULL mp, as
filesystems may not support the VOP_GETWRITEMOUNT() call. For
now, rely on two pointers, so that vn_finished_write() works
properly.
- Fix locking problems on exit, introduced at some past time,
some when snapshots came in, where a vnode might not be
unlocked before being vrele'd in various error situations.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.
Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,
Seigo Tanimura (tanimura) posted the initial delta.
I've polished it quite a bit reducing the need for locking and
adapting it for KSE.
Locks:
1 mutex in each filedesc
protects all the fields.
protects "struct file" initialization, while a struct file
is being changed from &badfileops -> &pipeops or something
the filedesc should be locked.
1 mutex in each struct file
protects the refcount fields.
doesn't protect anything else.
the flags used for garbage collection have been moved to
f_gcflag which was the FILLER short, this doesn't need
locking because the garbage collection is a single threaded
container.
could likely be made to use a pool mutex.
1 sx lock for the global filelist.
struct file * fhold(struct file *fp);
/* increments reference count on a file */
struct file * fhold_locked(struct file *fp);
/* like fhold but expects file to locked */
struct file * ffind_hold(struct thread *, int fd);
/* finds the struct file in thread, adds one reference and
returns it unlocked */
struct file * ffind_lock(struct thread *, int fd);
/* ffind_hold, but returns file locked */
I still have to smp-safe the fget cruft, I'll get to that asap.
can't acquire the mnt_lock without blocking. Normally non-forced
unmount attempts return EBUSY quickly if any vnodes are active, so
this just extends that behaviour to cover the per-mount mnt_lock
too.
(There has been some discussion, whether ENOENT or EBADF is more
appropriate. I choose the latter, since the operation is not supported
on the file descriptor at that time, even if it was, immediately before.)
PR: 32681
Reviewed by: dillon, iedowse, ...
Approved by: nectar
MFC after: 3 days
(pending RE approval)
structure changes now rather then piecemeal later on. mnt_nvnodelist
currently holds all the vnodes under the mount point. This will eventually
be split into a 'dirty' and 'clean' list. This way we only break kld's once
rather then twice. nvnodelist will eventually turn into the dirty list
and should remain compatible with the klds.
in vfs_syscalls.c. Although it did save some indirection, many of
those savings will be obscured with the impending commit of suser()
changes, and the result is increased code complexity. Also, once
p->p_ucred and td->td_ucred are distinguished, this will make
vfs_mount() use the correct thread credential, rather than the
process credential.
in vfs_syscalls.c:
if (mp->mnt_stat.f_owner != p->p_ucred->cr_uid &&
(error = suser_td(td)) != 0) {
unwrap_lots_of_stuff();
return (error);
}
to:
if (mp->mnt_stat.f_owner != p->p_ucred->cr_uid) {
error = suser_td(td);
if (error) {
unwrap_lots_of_stuff();
return (error);
}
}
This makes the code more readable when complex clauses are in use,
and minimizes conflicts for large outstanding patchsets modifying the
kernel authorization code (of which I have several), especially where
existing authorization and context code are combined in the same if()
conditional.
Obtained from: TrustedBSD Project
credentials rather than the real credentials. This is useful for
implementing GUI's which need to modify icons based on access rights,
but where use of open(2) is too expensive, use of stat(2) doesn't
reflect the file system's real protection model, and use of
access() suffers from real/effective credential confusion. This
implementation provides the same semantics as the call of the same
name on SCO OpenServer. Note: using this call improperly can
leave you subject to some of the same races present in the
access(2) call.
o To implement this, break out the basic logic of access(2) into
vpaccess(), which accepts a passed credential to perform the
invocation of VOP_ACCESS(). Add eaccess(2) to invoke vpaccess(),
and modify access(2) to use vpaccess().
Obtained from: TrustedBSD Project
