When project quota is active and is being used for directory tree
quota control, we disallow rename outside the current directory
tree. This requires a check to be made after all the inodes
involved in the rename are locked. We fail to unlock the inodes
correctly if we disallow the rename when the target is outside the
current directory tree. This results in a hang on the next access
to the inodes involved in failed rename.
Reported-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Tested-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
When we are about to add a new item to a transaction in recovery, we need
to check that it is valid first. Currently we just assert that header
magic number matches, but in production systems that is not present and we
add a corrupted transaction to the list to be processed. This results in a
kernel oops later when processing the corrupted transaction.
Instead, if we detect a corrupted transaction, abort recovery and leave
the user to clean up the mess that has occurred.
SGI-PV: 988145
SGI-Modid: xfs-linux-melb:xfs-kern:32356a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
When there is no memory left in the system, xfs_buf_get_noaddr()
can fail. If this happens at mount time during xlog_alloc_log()
we fail to catch the error and oops.
Catch the error from xfs_buf_get_noaddr(), and allow other memory
allocations to fail and catch those errors too. Report the error
to the console and fail the mount with ENOMEM.
Tested by manually injecting errors into xfs_buf_get_noaddr() and
xlog_alloc_log().
Version 2:
o remove unnecessary casts of the returned pointer from kmem_zalloc()
SGI-PV: 987246
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
When we create a directory, we reserve a number of blocks for the maximum
possible expansion of of the directory due to various btree splits,
freespace allocation, etc. Unfortunately, each allocation is not reflected
in the total number of blocks still available to the transaction, so the
maximal reservation is used over and over again.
This leads to problems where an allocation group has only enough blocks
for *some* of the allocations required for the directory modification.
After the first N allocations, the remaining blocks in the allocation
group drops below the total reservation, and subsequent allocations fail
because the allocator will not allow the allocation to proceed if the AG
does not have the enough blocks available for the entire allocation total.
This results in an ENOSPC occurring after an allocation has already
occurred. This results in aborting the directory operation (leaving the
directory in an inconsistent state) and cancelling a dirty transaction,
which results in a filesystem shutdown.
Avoid the problem by reflecting the number of blocks allocated in any
directory expansion in the total number of blocks available to the
modification in progress. This prevents a directory modification from
being aborted part way through with an ENOSPC.
SGI-PV: 988144
SGI-Modid: xfs-linux-melb:xfs-kern:32340a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
It's possible to have outstanding xfs_ioend_t's queued when the file size
is zero. This can happen in the direct I/O path when a direct I/O write
fails due to ENOSPC. In this case the xfs_ioend_t will still be queued (ie
xfs_end_io_direct() does not know that the I/O failed so can't force the
xfs_ioend_t to be flushed synchronously).
When we truncate a file on unlink we don't know to wait for these
xfs_ioend_ts and we can have a use-after-free situation if the inode is
reclaimed before the xfs_ioend_t is finally processed.
As was suggested by Dave Chinner lets wait for all I/Os to complete when
truncating the file size to zero.
SGI-PV: 981668
SGI-Modid: xfs-linux-melb:xfs-kern:32216a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Destroying the quota stuff on unmount can access the log - ie
XFS_QM_DONE() ends up in xfs_dqunlock() which calls
xfs_trans_unlocked_item() and then xfs_log_move_tail(). By this time the
log has already been destroyed. Just move the cleanup of the quota code
earlier in xfs_unmountfs() before the call to xfs_log_unmount(). Moving
XFS_QM_DONE() up near XFS_QM_DQPURGEALL() seems like a good spot.
SGI-PV: 987086
SGI-Modid: xfs-linux-melb:xfs-kern:32148a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Peter Leckie <pleckie@sgi.com>
Now that we've moved the readdir hack to the nfsd code, we can
remove the local version from the XFS code.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
replace open_bdev_excl/close_bdev_excl with variants taking fmode_t.
superblock gets the value used to mount it stored in sb->s_mode
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When we skip unrecognized options in xfs_fs_remount we should just break
out of the switch and not return because otherwise we may skip clearing
the xfs-internal read-only flag. This will only show up on some
operations like touch because most read-only checks are done by the VFS
which thinks this filesystem is r/w. Eventually we should replace the
XFS read-only flag with a helper that always checks the VFS flag to make
sure they can never get out of sync.
Bug reported and fix verified by Marcel Beister on #xfs.
Bug fix verified by updated xfstests/189.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Timothy Shimmin <tes@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.
This was posted for review some time ago and I believe its been in -mm
since then.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we disable barriers as soon as we get a buffer in xlog_iodone
that has the XBF_ORDERED flag cleared. But this can be the case not only
for buffers where the barrier failed, but also the first buffer of a
split log write in case of a log wraparound. Due to the disabled
barriers we can easily get directory corruption on unclean shutdowns.
So instead of using this check add a new buffer flag for failed barrier
writes.
This is a regression vs 2.6.26 caused by patch to use the right macro
to check for the ORDERED flag, as we previously got true returned for
every buffer.
Thanks to Toei Rei for reporting the bug.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: David Chinner <david@fromorbit.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yet another bug was found in xfs_iext_irec_compact_full() and while the
source of the bug was found it wasn't an easy task to track it down
because the conditions are very difficult to reproduce.
A HUGE thank-you goes to Russell Cattelan and Eric Sandeen for their
significant effort in tracking down the source of this corruption.
xfs_iext_irec_compact_full() and xfs_iext_irec_compact_pages() are almost
identical - they both compact indirect extent lists by moving extents from
subsequent buffers into earlier ones. xfs_iext_irec_compact_pages() only
moves extents if all of the extents in the next buffer will fit into the
empty space in the buffer before it. xfs_iext_irec_compact_full() will go
a step further and move part of the next buffer if all the extents wont
fit. It will then shift the remaining extents in the next buffer up to the
start of the buffer. The bug here was that we did not update er_extoff and
this caused extent list corruption.
It does not appear that this extra functionality gains us much. Calling
xfs_iext_irec_compact_pages() instead will do a good enough job at
compacting the indirect list and will be quicker too.
For the case in xfs_iext_indirect_to_direct() the total number of extents
in the indirect list will fit into one buffer so we will never need the
extra functionality of xfs_iext_irec_compact_full() there.
Also xfs_iext_irec_compact_pages() doesn't need to do a memmove() (the
buffers will never overlap) so we don't want the performance hit that can
incur.
SGI-PV: 987159
SGI-Modid: xfs-linux-melb:xfs-kern:32166a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
If we don't move all the records from the next buffer into the current
buffer then we need to update the er_extoff field of the next buffer as we
shift the remaining records to the start of the buffer.
SGI-PV: 987159
SGI-Modid: xfs-linux-melb:xfs-kern:32165a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Russell Cattelan <cattelan@thebarn.com>
When unreserving space with boundaries that are not block aligned we round
up the start and round down the end boundaries and then use this function,
xfs_zero_remaining_bytes(), to zero the parts of the blocks that got
dropped during the rounding. The problem is we don't consider if these
blocks are beyond eof. Worse still is if we encounter delayed allocations
beyond eof we will try to use the magic delayed allocation block number as
a real block number. If the file size is ever extended to expose these
blocks then we'll go through xfs_zero_eof() to zero them anyway.
SGI-PV: 983683
SGI-Modid: xfs-linux-melb:xfs-kern:32055a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
We have a use-after-free issue where log completions access buffers via
the buffer log item and the buffer has already been freed. Fix this by
taking a reference on the buffer when attaching the buffer log item and
release the hold when the buffer log item is detached and we no longer
need the buffer. Also create a new function xfs_buf_item_free() to combine
some common code.
SGI-PV: 985757
SGI-Modid: xfs-linux-melb:xfs-kern:32025a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
If we call xfs_lock_two_inodes() to grab both the iolock and the ilock,
then drop the ilocks on both inodes, then grab them again (as
xfs_swap_extents() does) then lockdep will report a locking order problem.
This is a false positive.
To avoid this, disallow xfs_lock_two_inodes() fom locking both inode locks
at once - force calers to make two separate calls. This means that nested
dropping and regaining of the ilocks will retain the same lockdep subclass
and so lockdep will not see anything wrong with this code.
SGI-PV: 986238
SGI-Modid: xfs-linux-melb:xfs-kern:31999a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Peter Leckie <pleckie@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
The current code in xlog_iodone() uses the wrong macro to check if the
barrier has been cleared due to an EOPNOTSUPP error form the lower layer.
SGI-PV: 986143
SGI-Modid: xfs-linux-melb:xfs-kern:31984a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Nathaniel W. Turner <nate@houseofnate.net>
Signed-off-by: Peter Leckie <pleckie@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
With the help from some tracing I found that we try to map extents beyond
eof when doing a direct I/O read. It appears that the way to inform the
generic direct I/O path (ie do_direct_IO()) that we have breached eof is
to return an unmapped buffer from xfs_get_blocks_direct(). This will cause
do_direct_IO() to jump to the hole handling code where is will check for
eof and then abort.
This problem was found because a direct I/O read was trying to map beyond
eof and was encountering delayed allocations. The delayed allocations
beyond eof are speculative allocations and they didn't get converted when
the direct I/O flushed the file because there was only enough space in the
current AG to convert and write out the dirty pages within eof. Note that
xfs_iomap_write_allocate() wont necessarily convert all the delayed
allocation passed to it - it will return after allocating the first extent
- so if the delayed allocation extends beyond eof then it will stay that
way.
SGI-PV: 983683
SGI-Modid: xfs-linux-melb:xfs-kern:31929a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Logically we would return an error in xfs_fs_remount code to prevent users
from believing they might have changed mount options using remount which
can't be changed.
But unfortunately mount(8) adds all options from mtab and fstab to the
mount arguments in some cases so we can't blindly reject options, but have
to check for each specified option if it actually differs from the
currently set option and only reject it if that's the case.
Until that is implemented we return success for every remount request, and
silently ignore all options that we can't actually change.
SGI-PV: 985710
SGI-Modid: xfs-linux-melb:xfs-kern:31908a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Memory allocations for log->l_grant_trace and iclog->ic_trace are done on
demand when the first event is logged. In xlog_state_get_iclog_space() we
call xlog_trace_iclog() under a spinlock and allocating memory here can
cause us to sleep with a spinlock held and deadlock the system.
For the log grant tracing we use KM_NOSLEEP but that means we can lose
trace entries. Since there is no locking to serialize the log grant
tracing we could race and have multiple allocations and leak memory.
So move the allocations to where we initialize the log/iclog structures.
Use KM_NOFS to avoid recursing into the filesystem and drop log->l_trace
since it's not even used.
SGI-PV: 983738
SGI-Modid: xfs-linux-melb:xfs-kern:31896a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
As pointed out during review d_add_ci argument order should match d_add,
so switch the dentry and inode arguments.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch lets the files using linux/version.h match the files that
#include it.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The patches that are intended to introduce copy-on-write credentials for 2.6.28
require abstraction of access to some fields of the task structure,
particularly for the case of one task accessing another's credentials where RCU
will have to be observed.
Introduced here are trivial no-op versions of the desired accessors for current
and other tasks so that other subsystems can start to be converted over more
easily.
Wrappers are introduced into a new header (linux/cred.h) for UID/GID,
EUID/EGID, SUID/SGID, FSUID/FSGID, cap_effective and current's subscribed
user_struct. These wrappers are macros because the ordering between header
files mitigates against making them inline functions.
linux/cred.h is #included from linux/sched.h.
Further, XFS is modified such that it no longer defines and uses parameterised
versions of current_fs[ug]id(), thus getting rid of the namespace collision
otherwise incurred.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
The ticket allocation code got reworked in 2.6.26 and we now free tickets
whereas before we used to cache them so the use-after-free went
undetected.
SGI-PV: 985525
SGI-Modid: xfs-linux-melb:xfs-kern:31877a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
Use KM_NOFS to prevent recursion back into the filesystem which can cause
deadlocks.
In the case of xfs_iread() we hold the lock on the inode cluster buffer
while allocating memory for the trace buffers. If we recurse back into XFS
to flush data that may require a transaction to allocate extents which
needs log space. This can deadlock with the xfsaild thread which can't
push the tail of the log because it is trying to get the inode cluster
buffer lock.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31838a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
Use KM_MAYFAIL for the m_perag allocation, we can deal with the error
easily and blocking forever during mount is not a good idea either.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31837a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
xfs_mount_free mostly frees the perag data, which is something that is
duplicated in the mount error path.
Move the XFS_QM_DONE call to the caller and remove the useless
mutex_destroy/spinlock_destroy calls so that we can re-use it for the
mount error path. Also rename it to xfs_free_perag to reflect what it
does.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31836a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
xfs_readsb is called before xfs_mount so xfs_freesb should be called after
xfs_unmountfs, too. This means it now happens after a few things during
the of xfs_unmount which all have nothing to do with the superblock.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31835a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
xfs_unmounts can't and shouldn't return errors so declare it as returning
void.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31833a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Remove all the useless flags and code keyed off it in xfs_mountfs.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31831a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
The root inode is allocated in xfs_mountfs so it should be release in
xfs_unmountfs. For the unmount case that means we do it after the the
xfs_sync(mp, SYNC_WAIT | SYNC_CLOSE) in the forced shutdown case and the
dmapi unmount event. Note that both reference the rip variable which might
be freed by that time in case inode flushing has kicked in, so strictly
speaking this might count as a bug fix
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31830a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
xfs_ichtime updates the xfs_inode and Linux inode timestamps just fine, no
need to call file_update_time and then copy the values over to the XFS
inode. The only additional thing in file_update_time are checks not
applicable to the write path.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31829a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
Port a little optmization from file_update_time to xfs_ichgtime, and only
update the timestamp and mark the inode dirty if the timestamp actually
changes in the timer tick resultion supported by the running kernel.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31827a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
In xfs_ialloc we just want to set all timestamps to the current time. We
don't need to mark the inode dirty like xfs_ichgtime does, and we don't
need nor want the opimizations in xfs_ichgtime that I will introduce in
the next patch.
So just opencode the timestamp update in xfs_ialloc, and remove the new
unused XFS_ICHGTIME_ACC case in xfs_ichgtime.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31825a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Now that all users of the sema_t are gone from XFS we can finally kill it.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31823a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Use the new completion flush code to implement the dquot flush lock.
Removes one of the final users of semaphores in the XFS code base.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31822a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Use the new completion flush code to implement the inode flush lock.
Removes one of the final users of semaphores in the XFS code base.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31817a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
The xfs_buf_t b_iodonesema is really just a semaphore that wants to be a
completion. Change it to a completion and remove the last user of the
sema_t from XFS.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31815a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
A lot of code has been converted away from semaphores, but there are still
comments that reference semaphore behaviour. The log code is the worst
offender. Update the comments to reflect what the code really does now.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31814a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
The alloc and inobt btree use the same agbp/agno pair in the btree_cur
union. Make them use the same bc_private.a union member so that code for
these two short form btree implementations can be shared.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31788a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Sanitize setting up the Linux indode.
Setting up the xfs_inode <-> inode link is opencoded in xfs_iget_core now
because that's the only place it needs to be done, xfs_initialize_vnode is
renamed to xfs_setup_inode and loses all superflous paramaters. The check
for I_NEW is removed because it always is true and the di_mode check moves
into xfs_iget_core because it's only needed there.
xfs_set_inodeops and xfs_revalidate_inode are merged into xfs_setup_inode
and the whole things is moved into xfs_iops.c where it belongs.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31782a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
All remaining bhv_vnode_t instance are in code that's more or less Linux
specific. (Well, for xfs_acl.c that could be argued, but that code is on
the removal list, too). So just do an s/bhv_vnode_t/struct inode/ over the
whole tree. We can clean up variable naming and some useless helpers
later.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31781a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
In various places we can just move a VFS_I call into the argument list of
called functions/macros instead of having a local bhv_vnode_t.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31776a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
When multiple inodes are locked in XFS it happens in order of the inode
number, with the everything but the first inode trylocked if any of the
previous inodes is in the AIL.
Except for the sorting of the inodes this logic is implemented in
xfs_lock_inodes, but also partially duplicated in xfs_lock_dir_and_entry
in a particularly stupid way adds a lock roundtrip if the inode ordering
is not optimal.
This patch adds a new helper xfs_lock_two_inodes that takes two inodes and
locks them in the most optimal way according to the above locking protocol
and uses it for all places that want to lock two inodes.
The only caller of xfs_lock_inodes is xfs_rename which might lock up to
four inodes.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31772a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Dave Chinner