1
Commit Graph

200422 Commits

Author SHA1 Message Date
Eric Sandeen
0cfc9255a1 ext4: re-inline ext4_rec_len_(to|from)_disk functions
commit 3d0518f4, "ext4: New rec_len encoding for very
large blocksizes" made several changes to this path, but from
a perf perspective, un-inlining ext4_rec_len_from_disk() seems
most significant.  This function is called from ext4_check_dir_entry(),
which on a file-creation workload is called extremely often.

I tested this with bonnie:

# bonnie++ -u root -s 0 -f -x 200 -d /mnt/test -n 32

(this does 200 iterations) and got this for the file creations:

ext4 stock:   Average =  21206.8 files/s
ext4 inlined: Average =  22346.7 files/s  (+5%)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-08-05 01:46:37 -04:00
Theodore Ts'o
8dd420466c jbd2: Remove t_handle_lock from start_this_handle()
This should remove the last exclusive lock from start_this_handle(),
so that we should now be able to start multiple transactions at the
same time on large SMP systems.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-08-03 21:38:29 -04:00
Theodore Ts'o
a931da6ac9 jbd2: Change j_state_lock to be a rwlock_t
Lockstat reports have shown that j_state_lock is a major source of
lock contention, especially on systems with more than 4 CPU cores.  So
change it to be a read/write spinlock.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-08-03 21:35:12 -04:00
Theodore Ts'o
a51dca9cd3 jbd2: Use atomic variables to avoid taking t_handle_lock in jbd2_journal_stop
By using an atomic_t for t_updates and t_outstanding credits, this
should allow us to not need to take transaction t_handle_lock in
jbd2_journal_stop().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-08-02 08:43:25 -04:00
Theodore Ts'o
8b67f04ab9 ext4: Add mount options in superblock
Allow mount options to be stored in the superblock.  Also add default
mount option bits for nobarrier, block_validity, discard, and nodelalloc.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-08-01 23:14:20 -04:00
Dmitry Monakhov
ca0e05e4b1 ext4: force block allocation on quota_off
Perform full sync procedure so that any delayed allocation blocks are
allocated so quota will be consistent.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-08-01 17:48:36 -04:00
Eric Sandeen
437f88cc03 ext4: fix freeze deadlock under IO
Commit 6b0310fbf0 caused a regression resulting in deadlocks
when freezing a filesystem which had active IO; the vfs_check_frozen
level (SB_FREEZE_WRITE) did not let the freeze-related IO syncing
through.  Duh.

Changing the test to FREEZE_TRANS should let the normal freeze
syncing get through the fs, but still block any transactions from
starting once the fs is completely frozen.

I tested this by running fsstress in the background while periodically
snapshotting the fs and running fsck on the result.  I ran into
occasional deadlocks, but different ones.  I think this is a
fine fix for the problem at hand, and the other deadlocky things
will need more investigation.

Reported-by: Phillip Susi <psusi@cfl.rr.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-08-01 17:33:29 -04:00
Theodore Ts'o
4538821993 ext4: drop inode from orphan list if ext4_delete_inode() fails
There were some error paths in ext4_delete_inode() which was not
dropping the inode from the orphan list.  This could lead to a BUG_ON
on umount when the orphan list is discovered to be non-empty.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-29 15:06:10 -04:00
Theodore Ts'o
f613dfcb33 ext4: check to make make sure bd_dev is set before dereferencing it
There are some drivers which may not set bdev->bd_dev.  So make sure
it is non-NULL before dereferencing it.

Google-Bug-Id: 1773557

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:08 -04:00
Eric Sandeen
cc937db74b jbd2: Make barrier messages less scary
Saying things like "sync failed" when a device does
not support barriers makes users slightly more worried than
they need to be; rather than talking about sync failures,
let's just state the barrier-based facts.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:08 -04:00
Eric Sandeen
e3570639c8 ext4: don't print scary messages for allocation failures post-abort
I often get emails containing the "This should not happen!!" message,
conveniently trimmed to remove things like:

sd 0:0:0:0: [sda] Unhandled error code
sd 0:0:0:0: [sda] Result: hostbyte=DID_OK driverbyte=DRIVER_TIMEOUT
sd 0:0:0:0: [sda] CDB: Write(10): 2a 00 03 13 c9 70 00 00 28 00
end_request: I/O error, dev sda, sector 51628400
Aborting journal on device dm-0-8.
EXT4-fs error (device dm-0): ext4_journal_start_sb: Detected aborted journal
EXT4-fs (dm-0): Remounting filesystem read-only

I don't think there is any value to the verbosity if the reason is
due to a filesystem abort; it just obfuscates the root cause.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:08 -04:00
Toshiyuki Okajima
d889dc8382 ext4: fix EFBIG edge case when writing to large non-extent file
By running the following reproducer, we can confirm that the write 
system call returns with 0 when it should return the error EFBIG.

#!/bin/sh

/bin/dd if=/dev/zero of=./img bs=1k count=1 seek=1024k > /dev/null 2>&1
/sbin/mkfs.ext3 -Fq ./img
/bin/mount -o loop -t ext4 ./img /mnt
/bin/touch /mnt/file
strace /bin/dd if=/dev/zero of=/mnt/file conv=notrunc bs=1k count=1 seek=$((2194719883264/1024)) 2>&1 | /bin/egrep "write.* 1024\) = "
/bin/umount /mnt
exit

Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Eric Sandeen <sandeen@redhat.com>
2010-07-27 11:56:07 -04:00
Eric Sandeen
79e8303677 ext4: fix ext4_get_blocks references
ext4_get_blocks got renamed to ext4_map_blocks, but left stale
comments and a prototype littered around.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:07 -04:00
Jan Kara
62d2b5f2dc ext4: Always journal quota file modifications
When journaled quota options are not specified, we do writes
to quota files just in data=ordered mode. This actually causes
warnings from JBD2 about dirty journaled buffer because ext4_getblk
unconditionally treats a block allocated by it as metadata. Since
quota actually is filesystem metadata, the easiest way to get rid
of the warning is to always treat quota writes as metadata...

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:07 -04:00
Cyrill Gorcunov
dcc7dae3cb ext4: Fix potential memory leak in ext4_fill_super
Under heavy memory pressure we may hit out of memory
situation and as result kstrdup'ed options will not be
freed. Fix it.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:07 -04:00
Theodore Ts'o
0c095c7f11 ext4: Don't error out the fs if the user tries to make a file too big
If the user attempts to make a non-extent-mapped file to be too large,
return EFBIG, but don't call ext4_std_err() which will end up marking
the file system as containing an error.

Thanks to Toshiyuki Okajima-san at Fujitsu for pointing this out.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:06 -04:00
Eric Sandeen
506bf2d821 ext4: allocate stripe-multiple IOs on stripe boundaries
For some reason, today mballoc only allocates IOs which are exactly
stripe-sized on a stripe boundary.  If you have a multiple (say, a
128k IO on a 64k stripe) you may end up unaligned.

It seems to me that a simple change to align stripe-multiple IOs
on stripe boundaries would be a very good idea, unless this breaks
some other mballoc heuristic for some reason...

Reported-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:06 -04:00
jiayingz@google.com (Jiaying Zhang)
5b3ff237be ext4: move aio completion after unwritten extent conversion
This patch is to be applied upon Christoph's "direct-io: move aio_complete
into ->end_io" patch. It adds iocb and result fields to struct ext4_io_end_t,
so that we can call aio_complete from  ext4_end_io_nolock() after the extent
conversion has finished.

I have verified with Christoph's aio-dio test that used to fail after a few
runs on an original kernel but now succeeds on the patched kernel.

See http://thread.gmane.org/gmane.comp.file-systems.ext4/19659 for details.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:06 -04:00
Christoph Hellwig
552ef8024f direct-io: move aio_complete into ->end_io
Filesystems with unwritten extent support must not complete an AIO request
until the transaction to convert the extent has been commited.  That means
the aio_complete calls needs to be moved into the ->end_io callback so
that the filesystem can control when to call it exactly.

This makes a bit of a mess out of dio_complete and the ->end_io callback
prototype even more complicated. 

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz> 
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:06 -04:00
Jiaying Zhang
5c521830cf ext4: Support discard requests when running in no-journal mode
Issue discard request in ext4_free_blocks() when ext4 has no journal and
is mounted with discard option.
    
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:05 -04:00
Theodore Ts'o
47def82672 jbd2: Remove __GFP_NOFAIL from jbd2 layer
__GFP_NOFAIL is going away, so add our own retry loop.  Also add
jbd2__journal_start() and jbd2__journal_restart() which take a gfp
mask, so that file systems can optionally (re)start transaction
handles using GFP_KERNEL.  If they do this, then they need to be
prepared to handle receiving an PTR_ERR(-ENOMEM) error, and be ready
to reflect that error up to userspace.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:05 -04:00
Amir G
4038968738 ext4: Fix block bitmap inconsistencies after a crash when deleting files
We have experienced bitmap inconsistencies after crash during file
delete under heavy load.  The crash is not file system related and I
the following patch in ext4_free_branches() fixes the recovery
problem.

If the transaction is restarted and there is a crash before the new
transaction is committed, then after recovery, the blocks that this
indirect block points to have been freed, but the indirect block
itself has not been freed and may still point to some of the free
blocks (because of the ext4_forget()).

So ext4_forget() should be called inside ext4_free_blocks() to avoid
this problem.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:05 -04:00
Joe Perches
a271fe8527 ext4: Remove unnecessary casts of private_data
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:04 -04:00
Theodore Ts'o
e5880d76ae ext4: fix potential NULL dereference while tracing
The allocation_context pointer can be NULL.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:04 -04:00
Theodore Ts'o
89eeddf033 ext4: Define s_jnl_backup_type in superblock
This has been in use by e2fsprogs for a while; define it to keep the
super block fields in sync.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:04 -04:00
Theodore Ts'o
66e61a9e95 ext4: Once a day, printk file system error information to dmesg
This allows us to grab any file system error messages by scraping
/var/log/messages.  This will make it easy for us to do error analysis
across the very large number of machines as we deploy ext4 across the
fleet.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:04 -04:00
Theodore Ts'o
1c13d5c087 ext4: Save error information to the superblock for analysis
Save number of file system errors, and the time function name, line
number, block number, and inode number of the first and most recent
errors reported on the file system in the superblock.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:03 -04:00
Theodore Ts'o
c398eda0e4 ext4: Pass line numbers to ext4_error() and friends
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:40 -04:00
Theodore Ts'o
60fd4da34d ext4: Cleanup ext4_check_dir_entry so __func__ is now implicit
Also start passing the line number to ext4_check_dir since we're going
to need it in upcoming patch.
    
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:54:40 -04:00
Theodore Ts'o
90c7201b97 ext4: Pass line number to ext4_journal_abort_handle()
This allows the error messages to include the line number

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-29 14:53:24 -04:00
Theodore Ts'o
e29136f80e ext4: Enhance ext4_grp_locked_error() to take block and function numbers
Also use a macro definition so that __func__ and __LINE__ is implicit.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-29 12:54:28 -04:00
Theodore Ts'o
c67d859e39 ext4: clean up ext4_abort() so __func__ is now implicit
Use a macro definition for ext4_abort() to clean up the .c files a wee
bit.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-29 11:07:07 -04:00
Theodore Ts'o
4a9cdec73f ext4: Add new superblock fields reserved for the Next3 snapshot feature
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-29 11:00:23 -04:00
Jan Kara
c6ac12a615 ext4: update ctime when changing the file's permission by setfacl
ext4 didn't update the ctime of the file when its permission was
changed.

Steps to reproduce:
 # touch aaa
 # stat -c %Z aaa
 1275289822
 # setfacl -m  'u::x,g::x,o::x' aaa
 # stat -c %Z aaa
 1275289822                         <- unchanged

But, according to the spec of the ctime, ext4 must update it.

Port of ext3 patch by Miao Xie <miaox@cn.fujitsu.com>.

CC: linux-ext4@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-15 12:19:59 -04:00
Christoph Hellwig
206f7ab4f4 ext4: remove vestiges of nobh support
The nobh option was only supported for writeback mode, but given that all
write paths actually create buffer heads it effectively was a no-op already.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-14 14:42:49 -04:00
Andi Kleen
5a0790c2c4 ext4: remove initialized but not read variables
No real bugs found, just removed some dead code.

Found by gcc 4.6's new warnings.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-14 13:28:03 -04:00
Theodore Ts'o
07a038245b ext4: Convert more i_flags references to use accessor functions
These changes are not ones which are likely to result in races, but
they should be fixed.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-14 09:54:48 -04:00
Theodore Ts'o
a0375156ca ext4: Clean up s_dirt handling
We don't need to set s_dirt in most of the ext4 code when journaling
is enabled.  In ext3/4 some of the summary statistics for # of free
inodes, blocks, and directories are calculated from the per-block
group statistics when the file system is mounted or unmounted.  As a
result the superblock doesn't have to be updated, either via the
journal or by setting s_dirt.  There are a few exceptions, most
notably when resizing the file system, where the superblock needs to
be modified --- and in that case it should be done as a journalled
operation if possible, and s_dirt set only in no-journal mode.

This patch will optimize out some unneeded disk writes when using ext4
with a journal.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-11 23:14:04 -04:00
Linus Torvalds
7e27d6e778 Linux 2.6.35-rc3 2010-06-11 19:14:04 -07:00
Linus Torvalds
4cea8706c3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  wimax/i2400m: fix missing endian correction read in fw loader
  net8139: fix a race at the end of NAPI
  pktgen: Fix accuracy of inter-packet delay.
  pkt_sched: gen_estimator: add a new lock
  net: deliver skbs on inactive slaves to exact matches
  ipv6: fix ICMP6_MIB_OUTERRORS
  r8169: fix mdio_read and update mdio_write according to hw specs
  gianfar: Revive the driver for eTSEC devices (disable timestamping)
  caif: fix a couple range checks
  phylib: Add support for the LXT973 phy.
  net: Print num_rx_queues imbalance warning only when there are allocated queues
2010-06-11 14:20:03 -07:00
Linus Torvalds
7ae1277a52 Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM / x86: Save/restore MISC_ENABLE register
2010-06-11 14:19:45 -07:00
Linus Torvalds
b25b550bb1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: The file argument for fsync() is never null
  Btrfs: handle ERR_PTR from posix_acl_from_xattr()
  Btrfs: avoid BUG when dropping root and reference in same transaction
  Btrfs: prohibit a operation of changing acl's mask when noacl mount option used
  Btrfs: should add a permission check for setfacl
  Btrfs: btrfs_lookup_dir_item() can return ERR_PTR
  Btrfs: btrfs_read_fs_root_no_name() returns ERR_PTRs
  Btrfs: unwind after btrfs_start_transaction() errors
  Btrfs: btrfs_iget() returns ERR_PTR
  Btrfs: handle kzalloc() failure in open_ctree()
  Btrfs: handle error returns from btrfs_lookup_dir_item()
  Btrfs: Fix BUG_ON for fs converted from extN
  Btrfs: Fix null dereference in relocation.c
  Btrfs: fix remap_file_pages error
  Btrfs: uninitialized data is check_path_shared()
  Btrfs: fix fallocate regression
  Btrfs: fix loop device on top of btrfs
2010-06-11 14:18:47 -07:00
Linus Torvalds
eda054770e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: clear bridge resource range if BIOS assigned bad one
  PCI: hotplug/cpqphp, fix NULL dereference
  Revert "PCI: create function symlinks in /sys/bus/pci/slots/N/"
  PCI: change resource collision messages from KERN_ERR to KERN_INFO
2010-06-11 14:15:44 -07:00
Yinghai Lu
837c4ef13c PCI: clear bridge resource range if BIOS assigned bad one
Yannick found that video does not work with 2.6.34.  The cause of this
bug was that the BIOS had assigned the wrong range to the PCI bridge
above the video device.  Before 2.6.34 the kernel would have shrunk
the size of the bridge window, but since
  d65245c PCI: don't shrink bridge resources
the kernel will avoid shrinking BIOS ranges.

So zero out the old range if we fail to claim it at boot time; this will
cause us to allocate a new range at startup, restoring the 2.6.34
behavior.

Fixes regression https://bugzilla.kernel.org/show_bug.cgi?id=16009.

Reported-by: Yannick <yannick.roehlly@free.fr>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11 13:24:51 -07:00
Jiri Slaby
a7ef7d1f5e PCI: hotplug/cpqphp, fix NULL dereference
There are devices out there which are PCI Hot-plug controllers with
compaq PCI IDs, but are not bridges, hence have pdev->subordinate
NULL. But cpqphp expects the pointer to be non-NULL.

Add a check to the probe function to avoid oopses like:
BUG: unable to handle kernel NULL pointer dereference at 00000050
IP: [<f82e3c41>] cpqhpc_probe+0x951/0x1120 [cpqphp]
*pdpt = 0000000033779001 *pde = 0000000000000000
...

The device here was:
00:0b.0 PCI Hot-plug controller [0804]: Compaq Computer Corporation PCI Hotplug Controller [0e11:a0f7] (rev 11)
	Subsystem: Compaq Computer Corporation Device [0e11:a2f8]

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11 13:10:21 -07:00
Jesse Barnes
3be434f024 Revert "PCI: create function symlinks in /sys/bus/pci/slots/N/"
This reverts commit 75568f8094.

Since they're just a convenience anyway, remove these symlinks since
they're causing duplicate filename errors in the wild.

Acked-by: Alex Chiang <achiang@canonical.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11 13:08:37 -07:00
Bjorn Helgaas
f6d440daeb PCI: change resource collision messages from KERN_ERR to KERN_INFO
We can often deal with PCI resource issues by moving devices around.  In
that case, there's no point in alarming the user with messages like these.
There are many bug reports where the message itself is the only problem,
e.g., https://bugs.launchpad.net/ubuntu/+source/linux/+bug/413419 .

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-06-11 13:08:14 -07:00
Dan Carpenter
6f902af400 Btrfs: The file argument for fsync() is never null
The "file" argument for fsync is never null so we can remove this check.

What drew my attention here is that 7ea8085910: "drop unused dentry
argument to ->fsync" introduced an unconditional dereference at the
start of the function and that generated a smatch warning.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11 15:57:40 -04:00
Dan Carpenter
834e74759a Btrfs: handle ERR_PTR from posix_acl_from_xattr()
posix_acl_from_xattr() returns both ERR_PTRs and null, but it's OK to
pass null values to set_cached_acl()

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11 15:57:39 -04:00
Sage Weil
15e7000095 Btrfs: avoid BUG when dropping root and reference in same transaction
If btrfs_ioctl_snap_destroy() deletes a snapshot but finishes
with end_transaction(), the cleaner kthread may come in and
drop the root in the same transaction.  If that's the case, the
root's refs still == 1 in the tree when btrfs_del_root() deletes
the item, because commit_fs_roots() hasn't updated it yet (that
happens during the commit).

This wasn't a problem before only because
btrfs_ioctl_snap_destroy() would commit the transaction before dropping
the dentry reference, so the dead root wouldn't get queued up until
after the fs root item was updated in the btree.

Since it is not an error to drop the root reference and the root in the
same transaction, just drop the BUG_ON() in btrfs_del_root().

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-06-11 15:57:39 -04:00