Commit graph

76 commits

Author SHA1 Message Date
Al Viro
1d3382cbf0 new helper: inode_unhashed()
note: for race-free uses you inode_lock held

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:24:15 -04:00
Christoph Hellwig
ebdec241d5 fs: kill block_prepare_write
__block_write_begin and block_prepare_write are identical except for slightly
different calling conventions.  Convert all callers to the __block_write_begin
calling conventions and drop block_prepare_write.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:18:20 -04:00
Stephen Hemminger
94d09a98cd reiserfs: constify xattr_handler
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:19 -04:00
Jeff Mahoney
fb2162df74 reiserfs: fix corruption during shrinking of xattrs
Commit 48b32a3553 ("reiserfs: use generic
xattr handlers") introduced a problem that causes corruption when extended
attributes are replaced with a smaller value.

The issue is that the reiserfs_setattr to shrink the xattr file was moved
from before the write to after the write.

The root issue has always been in the reiserfs xattr code, but was papered
over by the fact that in the shrink case, the file would just be expanded
again while the xattr was written.

The end result is that the last 8 bytes of xattr data are lost.

This patch fixes it to use new_size.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=14826

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reported-by: Christian Kujau <lists@nerdbynature.de>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Edward Shishkin <edward.shishkin@gmail.com>
Cc: Jethro Beekman <kernel@jbeekman.nl>
Cc: Greg Surbey <gregsurbey@hotmail.com>
Cc: Marco Gatti <marco.gatti@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:24 -07:00
Jeff Mahoney
cac36f7071 reiserfs: fix permissions on .reiserfs_priv
Commit 677c9b2e39 ("reiserfs: remove
privroot hiding in lookup") removed the magic from the lookup code to hide
the .reiserfs_priv directory since it was getting loaded at mount-time
instead.  The intent was that the entry would be hidden from the user via
a poisoned d_compare, but this was faulty.

This introduced a security issue where unprivileged users could access and
modify extended attributes or ACLs belonging to other users, including
root.

This patch resolves the issue by properly hiding .reiserfs_priv.  This was
the intent of the xattr poisoning code, but it appears to have never
worked as expected.  This is fixed by using d_revalidate instead of
d_compare.

This patch makes -oexpose_privroot a no-op.  I'm fine leaving it this way.
The effort involved in working out the corner cases wrt permissions and
caching outweigh the benefit of the feature.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Edward Shishkin <edward.shishkin@gmail.com>
Reported-by: Matt McCutchen <matt@mattmccutchen.net>
Tested-by: Matt McCutchen <matt@mattmccutchen.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:24 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Christoph Hellwig
907f4554e2 dquot: move dquot initialization responsibility into the filesystem
Currently various places in the VFS call vfs_dq_init directly.  This means
we tie the quota code into the VFS.  Get rid of that and make the
filesystem responsible for the initialization.   For most metadata operations
this is a straight forward move into the methods, but for truncate and
open it's a bit more complicated.

For truncate we currently only call vfs_dq_init for the sys_truncate case
because open already takes care of it for ftruncate and open(O_TRUNC) - the
new code causes an additional vfs_dq_init for those which is harmless.

For open the initialization is moved from do_filp_open into the open method,
which means it happens slightly earlier now, and only for regular files.
The latter is fine because we don't need to initialize it for operations
on special files, and we already do it as part of the namespace operations
for directories.

Add a dquot_file_open helper that filesystems that support generic quotas
can use to fill in ->open.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2010-03-05 00:20:30 +01:00
Linus Torvalds
82062e7b50 Merge branch 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing
* 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  reiserfs: Relax reiserfs_xattr_set_handle() while acquiring xattr locks
  reiserfs: Fix unreachable statement
  reiserfs: Don't call reiserfs_get_acl() with the reiserfs lock
  reiserfs: Relax lock on xattr removing
  reiserfs: Relax the lock before truncating pages
  reiserfs: Fix recursive lock on lchown
  reiserfs: Fix mistake in down_write() conversion
2010-01-08 14:03:55 -08:00
Frederic Weisbecker
31370f62ba reiserfs: Relax reiserfs_xattr_set_handle() while acquiring xattr locks
Fix remaining xattr locks acquired in reiserfs_xattr_set_handle()
while we are holding the reiserfs lock to avoid lock inversions.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-07 16:02:53 +01:00
Frederic Weisbecker
4f3be1b5a9 reiserfs: Relax lock on xattr removing
When we remove an xattr, we call lookup_and_delete_xattr()
that takes some private xattr inodes mutexes. But we hold
the reiserfs lock at this time, which leads to dependency
inversions.

We can safely call lookup_and_delete_xattr() without the
reiserfs lock, where xattr inodes lookups only need the
xattr inodes mutexes.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-05 08:00:50 +01:00
Frederic Weisbecker
f3e22f48f3 reiserfs: Fix mistake in down_write() conversion
Fix a mistake in commit 0719d34347
(reiserfs: Fix reiserfs lock <-> i_xattr_sem dependency inversion)
that has converted a down_write() into a down_read() accidentally.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-03 03:44:53 +01:00
Linus Torvalds
45d28b0972 Merge branch 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing
* 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  reiserfs: Safely acquire i_mutex from xattr_rmdir
  reiserfs: Safely acquire i_mutex from reiserfs_for_each_xattr
  reiserfs: Fix journal mutex <-> inode mutex lock inversion
  reiserfs: Fix unwanted recursive reiserfs lock in reiserfs_unlink()
  reiserfs: Relax lock before open xattr dir in reiserfs_xattr_set_handle()
  reiserfs: Relax reiserfs lock while freeing the journal
  reiserfs: Fix reiserfs lock <-> i_mutex dependency inversion on xattr
  reiserfs: Warn on lock relax if taken recursively
  reiserfs: Fix reiserfs lock <-> i_xattr_sem dependency inversion
  reiserfs: Fix remaining in-reclaim-fs <-> reclaim-fs-on locking inversion
  reiserfs: Fix reiserfs lock <-> inode mutex dependency inversion
  reiserfs: Fix reiserfs lock and journal lock inversion dependency
  reiserfs: Fix possible recursive lock
2010-01-02 11:17:05 -08:00
Frederic Weisbecker
835d5247d9 reiserfs: Safely acquire i_mutex from xattr_rmdir
Relax the reiserfs lock before taking the inode mutex from
xattr_rmdir() to avoid the usual reiserfs lock <-> inode mutex
bad dependency.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02 01:59:48 +01:00
Frederic Weisbecker
8b513f56d4 reiserfs: Safely acquire i_mutex from reiserfs_for_each_xattr
Relax the reiserfs lock before taking the inode mutex from
reiserfs_for_each_xattr() to avoid the usual bad dependencies:

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #179
-------------------------------------------------------
rm/3242 is trying to acquire lock:
 (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c11428ef>] reiserfs_for_each_xattr+0x23f/0x290

but task is already holding lock:
 (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1143389>] reiserfs_write_lock+0x29/0x40

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&REISERFS_SB(s)->lock){+.+.+.}:
       [<c105ea7f>] __lock_acquire+0x11ff/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401aab>] mutex_lock_nested+0x5b/0x340
       [<c1143339>] reiserfs_write_lock_once+0x29/0x50
       [<c1117022>] reiserfs_lookup+0x62/0x140
       [<c10bd85f>] __lookup_hash+0xef/0x110
       [<c10bf21d>] lookup_one_len+0x8d/0xc0
       [<c1141e3a>] open_xa_dir+0xea/0x1b0
       [<c1142720>] reiserfs_for_each_xattr+0x70/0x290
       [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60
       [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150
       [<c10c9c32>] generic_delete_inode+0xa2/0x170
       [<c10c9d4f>] generic_drop_inode+0x4f/0x70
       [<c10c8b07>] iput+0x47/0x50
       [<c10c0965>] do_unlinkat+0xd5/0x160
       [<c10c0b13>] sys_unlinkat+0x23/0x40
       [<c1002ec4>] sysenter_do_call+0x12/0x32

-> #0 (&sb->s_type->i_mutex_key#4/3){+.+.+.}:
       [<c105f176>] __lock_acquire+0x18f6/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401aab>] mutex_lock_nested+0x5b/0x340
       [<c11428ef>] reiserfs_for_each_xattr+0x23f/0x290
       [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60
       [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150
       [<c10c9c32>] generic_delete_inode+0xa2/0x170
       [<c10c9d4f>] generic_drop_inode+0x4f/0x70
       [<c10c8b07>] iput+0x47/0x50
       [<c10c0965>] do_unlinkat+0xd5/0x160
       [<c10c0b13>] sys_unlinkat+0x23/0x40
       [<c1002ec4>] sysenter_do_call+0x12/0x32

other info that might help us debug this:

1 lock held by rm/3242:
 #0:  (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1143389>] reiserfs_write_lock+0x29/0x40

stack backtrace:
Pid: 3242, comm: rm Not tainted 2.6.32-atom #179
Call Trace:
 [<c13ffa13>] ? printk+0x18/0x1a
 [<c105d33a>] print_circular_bug+0xca/0xd0
 [<c105f176>] __lock_acquire+0x18f6/0x19e0
 [<c105c932>] ? mark_held_locks+0x62/0x80
 [<c105cc3b>] ? trace_hardirqs_on+0xb/0x10
 [<c1401098>] ? mutex_unlock+0x8/0x10
 [<c105f2c8>] lock_acquire+0x68/0x90
 [<c11428ef>] ? reiserfs_for_each_xattr+0x23f/0x290
 [<c11428ef>] ? reiserfs_for_each_xattr+0x23f/0x290
 [<c1401aab>] mutex_lock_nested+0x5b/0x340
 [<c11428ef>] ? reiserfs_for_each_xattr+0x23f/0x290
 [<c11428ef>] reiserfs_for_each_xattr+0x23f/0x290
 [<c1143180>] ? delete_one_xattr+0x0/0x100
 [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60
 [<c1143339>] ? reiserfs_write_lock_once+0x29/0x50
 [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150
 [<c11b0d4f>] ? _atomic_dec_and_lock+0x4f/0x70
 [<c111e990>] ? reiserfs_delete_inode+0x0/0x150
 [<c10c9c32>] generic_delete_inode+0xa2/0x170
 [<c10c9d4f>] generic_drop_inode+0x4f/0x70
 [<c10c8b07>] iput+0x47/0x50
 [<c10c0965>] do_unlinkat+0xd5/0x160
 [<c1401098>] ? mutex_unlock+0x8/0x10
 [<c10c3e0d>] ? vfs_readdir+0x7d/0xb0
 [<c10c3af0>] ? filldir64+0x0/0xf0
 [<c1002ef3>] ? sysenter_exit+0xf/0x16
 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170
 [<c10c0b13>] sys_unlinkat+0x23/0x40
 [<c1002ec4>] sysenter_do_call+0x12/0x32

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02 01:59:14 +01:00
Frederic Weisbecker
4dd859697f reiserfs: Fix journal mutex <-> inode mutex lock inversion
We need to relax the reiserfs lock before locking the inode mutex
from xattr_unlink(), otherwise we'll face the usual bad dependencies:

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #178
-------------------------------------------------------
rm/3202 is trying to acquire lock:
 (&journal->j_mutex){+.+...}, at: [<c113c234>] do_journal_begin_r+0x94/0x360

but task is already holding lock:
 (&sb->s_type->i_mutex_key#4/2){+.+...}, at: [<c1142a67>] xattr_unlink+0x57/0xb0

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&sb->s_type->i_mutex_key#4/2){+.+...}:
       [<c105ea7f>] __lock_acquire+0x11ff/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401a7b>] mutex_lock_nested+0x5b/0x340
       [<c1142a67>] xattr_unlink+0x57/0xb0
       [<c1143179>] delete_one_xattr+0x29/0x100
       [<c11427bb>] reiserfs_for_each_xattr+0x10b/0x290
       [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60
       [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150
       [<c10c9c32>] generic_delete_inode+0xa2/0x170
       [<c10c9d4f>] generic_drop_inode+0x4f/0x70
       [<c10c8b07>] iput+0x47/0x50
       [<c10c0965>] do_unlinkat+0xd5/0x160
       [<c10c0b13>] sys_unlinkat+0x23/0x40
       [<c1002ec4>] sysenter_do_call+0x12/0x32

-> #1 (&REISERFS_SB(s)->lock){+.+.+.}:
       [<c105ea7f>] __lock_acquire+0x11ff/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401a7b>] mutex_lock_nested+0x5b/0x340
       [<c1143359>] reiserfs_write_lock+0x29/0x40
       [<c113c23c>] do_journal_begin_r+0x9c/0x360
       [<c113c680>] journal_begin+0x80/0x130
       [<c1127363>] reiserfs_remount+0x223/0x4e0
       [<c10b6dd6>] do_remount_sb+0xa6/0x140
       [<c10ce6a0>] do_mount+0x560/0x750
       [<c10ce914>] sys_mount+0x84/0xb0
       [<c1002ec4>] sysenter_do_call+0x12/0x32

-> #0 (&journal->j_mutex){+.+...}:
       [<c105f176>] __lock_acquire+0x18f6/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401a7b>] mutex_lock_nested+0x5b/0x340
       [<c113c234>] do_journal_begin_r+0x94/0x360
       [<c113c680>] journal_begin+0x80/0x130
       [<c1116d63>] reiserfs_unlink+0x83/0x2e0
       [<c1142a74>] xattr_unlink+0x64/0xb0
       [<c1143179>] delete_one_xattr+0x29/0x100
       [<c11427bb>] reiserfs_for_each_xattr+0x10b/0x290
       [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60
       [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150
       [<c10c9c32>] generic_delete_inode+0xa2/0x170
       [<c10c9d4f>] generic_drop_inode+0x4f/0x70
       [<c10c8b07>] iput+0x47/0x50
       [<c10c0965>] do_unlinkat+0xd5/0x160
       [<c10c0b13>] sys_unlinkat+0x23/0x40
       [<c1002ec4>] sysenter_do_call+0x12/0x32

other info that might help us debug this:

2 locks held by rm/3202:
 #0:  (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c114274b>] reiserfs_for_each_xattr+0x9b/0x290
 #1:  (&sb->s_type->i_mutex_key#4/2){+.+...}, at: [<c1142a67>] xattr_unlink+0x57/0xb0

stack backtrace:
Pid: 3202, comm: rm Not tainted 2.6.32-atom #178
Call Trace:
 [<c13ff9e3>] ? printk+0x18/0x1a
 [<c105d33a>] print_circular_bug+0xca/0xd0
 [<c105f176>] __lock_acquire+0x18f6/0x19e0
 [<c1142a67>] ? xattr_unlink+0x57/0xb0
 [<c105f2c8>] lock_acquire+0x68/0x90
 [<c113c234>] ? do_journal_begin_r+0x94/0x360
 [<c113c234>] ? do_journal_begin_r+0x94/0x360
 [<c1401a7b>] mutex_lock_nested+0x5b/0x340
 [<c113c234>] ? do_journal_begin_r+0x94/0x360
 [<c113c234>] do_journal_begin_r+0x94/0x360
 [<c10411b6>] ? run_timer_softirq+0x1a6/0x220
 [<c103cb00>] ? __do_softirq+0x50/0x140
 [<c113c680>] journal_begin+0x80/0x130
 [<c103cba2>] ? __do_softirq+0xf2/0x140
 [<c104f72f>] ? hrtimer_interrupt+0xdf/0x220
 [<c1116d63>] reiserfs_unlink+0x83/0x2e0
 [<c105c932>] ? mark_held_locks+0x62/0x80
 [<c11b8d08>] ? trace_hardirqs_on_thunk+0xc/0x10
 [<c1002fd8>] ? restore_all_notrace+0x0/0x18
 [<c1142a67>] ? xattr_unlink+0x57/0xb0
 [<c1142a74>] xattr_unlink+0x64/0xb0
 [<c1143179>] delete_one_xattr+0x29/0x100
 [<c11427bb>] reiserfs_for_each_xattr+0x10b/0x290
 [<c1143150>] ? delete_one_xattr+0x0/0x100
 [<c1401cb9>] ? mutex_lock_nested+0x299/0x340
 [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60
 [<c1143309>] ? reiserfs_write_lock_once+0x29/0x50
 [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150
 [<c11b0d1f>] ? _atomic_dec_and_lock+0x4f/0x70
 [<c111e990>] ? reiserfs_delete_inode+0x0/0x150
 [<c10c9c32>] generic_delete_inode+0xa2/0x170
 [<c10c9d4f>] generic_drop_inode+0x4f/0x70
 [<c10c8b07>] iput+0x47/0x50
 [<c10c0965>] do_unlinkat+0xd5/0x160
 [<c1401068>] ? mutex_unlock+0x8/0x10
 [<c10c3e0d>] ? vfs_readdir+0x7d/0xb0
 [<c10c3af0>] ? filldir64+0x0/0xf0
 [<c1002ef3>] ? sysenter_exit+0xf/0x16
 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170
 [<c10c0b13>] sys_unlinkat+0x23/0x40
 [<c1002ec4>] sysenter_do_call+0x12/0x32

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02 01:58:32 +01:00
Frederic Weisbecker
3f14fea6bb reiserfs: Relax lock before open xattr dir in reiserfs_xattr_set_handle()
We call xattr_lookup() from reiserfs_xattr_get(). We then hold
the reiserfs lock when we grab the i_mutex. But later, we may
relax the reiserfs lock, creating dependency inversion between
both locks.

The lookups and creation jobs ar already protected by the
inode mutex, so we can safely relax the reiserfs lock, dropping
the unwanted reiserfs lock -> i_mutex dependency, as shown
in the following lockdep report:

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #173
-------------------------------------------------------
cp/3204 is trying to acquire lock:
 (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c11432b9>] reiserfs_write_lock_once+0x29/0x50

but task is already holding lock:
 (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#4/3){+.+.+.}:
       [<c105ea7f>] __lock_acquire+0x11ff/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401a2b>] mutex_lock_nested+0x5b/0x340
       [<c1141d83>] open_xa_dir+0x43/0x1b0
       [<c1142722>] reiserfs_for_each_xattr+0x62/0x260
       [<c114299a>] reiserfs_delete_xattrs+0x1a/0x60
       [<c111ea1f>] reiserfs_delete_inode+0x9f/0x150
       [<c10c9c32>] generic_delete_inode+0xa2/0x170
       [<c10c9d4f>] generic_drop_inode+0x4f/0x70
       [<c10c8b07>] iput+0x47/0x50
       [<c10c0965>] do_unlinkat+0xd5/0x160
       [<c10c0a00>] sys_unlink+0x10/0x20
       [<c1002ec4>] sysenter_do_call+0x12/0x32

-> #0 (&REISERFS_SB(s)->lock){+.+.+.}:
       [<c105f176>] __lock_acquire+0x18f6/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401a2b>] mutex_lock_nested+0x5b/0x340
       [<c11432b9>] reiserfs_write_lock_once+0x29/0x50
       [<c1117012>] reiserfs_lookup+0x62/0x140
       [<c10bd85f>] __lookup_hash+0xef/0x110
       [<c10bf21d>] lookup_one_len+0x8d/0xc0
       [<c1141e2a>] open_xa_dir+0xea/0x1b0
       [<c1141fe5>] xattr_lookup+0x15/0x160
       [<c1142476>] reiserfs_xattr_get+0x56/0x2a0
       [<c1144042>] reiserfs_get_acl+0xa2/0x360
       [<c114461a>] reiserfs_cache_default_acl+0x3a/0x160
       [<c111789c>] reiserfs_mkdir+0x6c/0x2c0
       [<c10bea96>] vfs_mkdir+0xd6/0x180
       [<c10c0c10>] sys_mkdirat+0xc0/0xd0
       [<c10c0c40>] sys_mkdir+0x20/0x30
       [<c1002ec4>] sysenter_do_call+0x12/0x32

other info that might help us debug this:

2 locks held by cp/3204:
 #0:  (&sb->s_type->i_mutex_key#4/1){+.+.+.}, at: [<c10bd8d6>] lookup_create+0x26/0xa0
 #1:  (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0

stack backtrace:
Pid: 3204, comm: cp Not tainted 2.6.32-atom #173
Call Trace:
 [<c13ff993>] ? printk+0x18/0x1a
 [<c105d33a>] print_circular_bug+0xca/0xd0
 [<c105f176>] __lock_acquire+0x18f6/0x19e0
 [<c105d3aa>] ? check_usage+0x6a/0x460
 [<c105f2c8>] lock_acquire+0x68/0x90
 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
 [<c1401a2b>] mutex_lock_nested+0x5b/0x340
 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
 [<c11432b9>] reiserfs_write_lock_once+0x29/0x50
 [<c1117012>] reiserfs_lookup+0x62/0x140
 [<c105ccca>] ? debug_check_no_locks_freed+0x8a/0x140
 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170
 [<c10bd85f>] __lookup_hash+0xef/0x110
 [<c10bf21d>] lookup_one_len+0x8d/0xc0
 [<c1141e2a>] open_xa_dir+0xea/0x1b0
 [<c1141fe5>] xattr_lookup+0x15/0x160
 [<c1142476>] reiserfs_xattr_get+0x56/0x2a0
 [<c1144042>] reiserfs_get_acl+0xa2/0x360
 [<c10ca2e7>] ? new_inode+0x27/0xa0
 [<c114461a>] reiserfs_cache_default_acl+0x3a/0x160
 [<c1402eb7>] ? _spin_unlock+0x27/0x40
 [<c111789c>] reiserfs_mkdir+0x6c/0x2c0
 [<c10c7cb8>] ? __d_lookup+0x108/0x190
 [<c105c932>] ? mark_held_locks+0x62/0x80
 [<c1401c8d>] ? mutex_lock_nested+0x2bd/0x340
 [<c10bd17a>] ? generic_permission+0x1a/0xa0
 [<c11788fe>] ? security_inode_permission+0x1e/0x20
 [<c10bea96>] vfs_mkdir+0xd6/0x180
 [<c10c0c10>] sys_mkdirat+0xc0/0xd0
 [<c10505c6>] ? up_read+0x16/0x30
 [<c1002fd8>] ? restore_all_notrace+0x0/0x18
 [<c10c0c40>] sys_mkdir+0x20/0x30
 [<c1002ec4>] sysenter_do_call+0x12/0x32

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02 01:57:01 +01:00
Frederic Weisbecker
27026a05bb reiserfs: Fix reiserfs lock <-> i_mutex dependency inversion on xattr
While deleting the xattrs of an inode, we hold the reiserfs lock
and grab the inode->i_mutex of the targeted inode and the root
private xattr directory.

Later on, we may relax the reiserfs lock for various reasons, this
creates inverted dependencies.

We can remove the reiserfs lock -> i_mutex dependency by relaxing
the former before calling open_xa_dir(). This is fine because the
lookup and creation of xattr private directories done in
open_xa_dir() are covered by the targeted inode mutexes. And deeper
operations in the tree are still done under the write lock.

This fixes the following lockdep report:

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #173
-------------------------------------------------------
cp/3204 is trying to acquire lock:
 (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c11432b9>] reiserfs_write_lock_once+0x29/0x50

but task is already holding lock:
 (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#4/3){+.+.+.}:
       [<c105ea7f>] __lock_acquire+0x11ff/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401a2b>] mutex_lock_nested+0x5b/0x340
       [<c1141d83>] open_xa_dir+0x43/0x1b0
       [<c1142722>] reiserfs_for_each_xattr+0x62/0x260
       [<c114299a>] reiserfs_delete_xattrs+0x1a/0x60
       [<c111ea1f>] reiserfs_delete_inode+0x9f/0x150
       [<c10c9c32>] generic_delete_inode+0xa2/0x170
       [<c10c9d4f>] generic_drop_inode+0x4f/0x70
       [<c10c8b07>] iput+0x47/0x50
       [<c10c0965>] do_unlinkat+0xd5/0x160
       [<c10c0a00>] sys_unlink+0x10/0x20
       [<c1002ec4>] sysenter_do_call+0x12/0x32

-> #0 (&REISERFS_SB(s)->lock){+.+.+.}:
       [<c105f176>] __lock_acquire+0x18f6/0x19e0
       [<c105f2c8>] lock_acquire+0x68/0x90
       [<c1401a2b>] mutex_lock_nested+0x5b/0x340
       [<c11432b9>] reiserfs_write_lock_once+0x29/0x50
       [<c1117012>] reiserfs_lookup+0x62/0x140
       [<c10bd85f>] __lookup_hash+0xef/0x110
       [<c10bf21d>] lookup_one_len+0x8d/0xc0
       [<c1141e2a>] open_xa_dir+0xea/0x1b0
       [<c1141fe5>] xattr_lookup+0x15/0x160
       [<c1142476>] reiserfs_xattr_get+0x56/0x2a0
       [<c1144042>] reiserfs_get_acl+0xa2/0x360
       [<c114461a>] reiserfs_cache_default_acl+0x3a/0x160
       [<c111789c>] reiserfs_mkdir+0x6c/0x2c0
       [<c10bea96>] vfs_mkdir+0xd6/0x180
       [<c10c0c10>] sys_mkdirat+0xc0/0xd0
       [<c10c0c40>] sys_mkdir+0x20/0x30
       [<c1002ec4>] sysenter_do_call+0x12/0x32

other info that might help us debug this:

2 locks held by cp/3204:
 #0:  (&sb->s_type->i_mutex_key#4/1){+.+.+.}, at: [<c10bd8d6>] lookup_create+0x26/0xa0
 #1:  (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0

stack backtrace:
Pid: 3204, comm: cp Not tainted 2.6.32-atom #173
Call Trace:
 [<c13ff993>] ? printk+0x18/0x1a
 [<c105d33a>] print_circular_bug+0xca/0xd0
 [<c105f176>] __lock_acquire+0x18f6/0x19e0
 [<c105d3aa>] ? check_usage+0x6a/0x460
 [<c105f2c8>] lock_acquire+0x68/0x90
 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
 [<c1401a2b>] mutex_lock_nested+0x5b/0x340
 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
 [<c11432b9>] reiserfs_write_lock_once+0x29/0x50
 [<c1117012>] reiserfs_lookup+0x62/0x140
 [<c105ccca>] ? debug_check_no_locks_freed+0x8a/0x140
 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170
 [<c10bd85f>] __lookup_hash+0xef/0x110
 [<c10bf21d>] lookup_one_len+0x8d/0xc0
 [<c1141e2a>] open_xa_dir+0xea/0x1b0
 [<c1141fe5>] xattr_lookup+0x15/0x160
 [<c1142476>] reiserfs_xattr_get+0x56/0x2a0
 [<c1144042>] reiserfs_get_acl+0xa2/0x360
 [<c10ca2e7>] ? new_inode+0x27/0xa0
 [<c114461a>] reiserfs_cache_default_acl+0x3a/0x160
 [<c1402eb7>] ? _spin_unlock+0x27/0x40
 [<c111789c>] reiserfs_mkdir+0x6c/0x2c0
 [<c10c7cb8>] ? __d_lookup+0x108/0x190
 [<c105c932>] ? mark_held_locks+0x62/0x80
 [<c1401c8d>] ? mutex_lock_nested+0x2bd/0x340
 [<c10bd17a>] ? generic_permission+0x1a/0xa0
 [<c11788fe>] ? security_inode_permission+0x1e/0x20
 [<c10bea96>] vfs_mkdir+0xd6/0x180
 [<c10c0c10>] sys_mkdirat+0xc0/0xd0
 [<c10505c6>] ? up_read+0x16/0x30
 [<c1002fd8>] ? restore_all_notrace+0x0/0x18
 [<c10c0c40>] sys_mkdir+0x20/0x30
 [<c1002ec4>] sysenter_do_call+0x12/0x32

v2: Don't drop reiserfs_mutex_lock_nested_safe() as we'll still
    need it later

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02 01:54:47 +01:00
Frederic Weisbecker
0719d34347 reiserfs: Fix reiserfs lock <-> i_xattr_sem dependency inversion
i_xattr_sem depends on the reiserfs lock. But after we grab
i_xattr_sem, we may relax/relock the reiserfs lock while waiting
on a freezed filesystem, creating a dependency inversion between
the two locks.

In order to avoid the i_xattr_sem -> reiserfs lock dependency, let's
create a reiserfs_down_read_safe() that acts like
reiserfs_mutex_lock_safe(): relax the reiserfs lock while grabbing
another lock to avoid undesired dependencies induced by the
heivyweight reiserfs lock.

This fixes the following warning:

[  990.005931] =======================================================
[  990.012373] [ INFO: possible circular locking dependency detected ]
[  990.013233] 2.6.33-rc1 #1
[  990.013233] -------------------------------------------------------
[  990.013233] dbench/1891 is trying to acquire lock:
[  990.013233]  (&REISERFS_SB(s)->lock){+.+.+.}, at: [<ffffffff81159505>] reiserfs_write_lock+0x35/0x50
[  990.013233]
[  990.013233] but task is already holding lock:
[  990.013233]  (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}, at: [<ffffffff8115899a>] reiserfs_xattr_set_handle+0x8a/0x470
[  990.013233]
[  990.013233] which lock already depends on the new lock.
[  990.013233]
[  990.013233]
[  990.013233] the existing dependency chain (in reverse order) is:
[  990.013233]
[  990.013233] -> #1 (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}:
[  990.013233]        [<ffffffff81063afc>] __lock_acquire+0xf9c/0x1560
[  990.013233]        [<ffffffff8106414f>] lock_acquire+0x8f/0xb0
[  990.013233]        [<ffffffff814ac194>] down_write+0x44/0x80
[  990.013233]        [<ffffffff8115899a>] reiserfs_xattr_set_handle+0x8a/0x470
[  990.013233]        [<ffffffff81158e30>] reiserfs_xattr_set+0xb0/0x150
[  990.013233]        [<ffffffff8115a6aa>] user_set+0x8a/0x90
[  990.013233]        [<ffffffff8115901a>] reiserfs_setxattr+0xaa/0xb0
[  990.013233]        [<ffffffff810e2596>] __vfs_setxattr_noperm+0x36/0xa0
[  990.013233]        [<ffffffff810e26bc>] vfs_setxattr+0xbc/0xc0
[  990.013233]        [<ffffffff810e2780>] setxattr+0xc0/0x150
[  990.013233]        [<ffffffff810e289d>] sys_fsetxattr+0x8d/0xa0
[  990.013233]        [<ffffffff81002dab>] system_call_fastpath+0x16/0x1b
[  990.013233]
[  990.013233] -> #0 (&REISERFS_SB(s)->lock){+.+.+.}:
[  990.013233]        [<ffffffff81063e30>] __lock_acquire+0x12d0/0x1560
[  990.013233]        [<ffffffff8106414f>] lock_acquire+0x8f/0xb0
[  990.013233]        [<ffffffff814aba77>] __mutex_lock_common+0x47/0x3b0
[  990.013233]        [<ffffffff814abebe>] mutex_lock_nested+0x3e/0x50
[  990.013233]        [<ffffffff81159505>] reiserfs_write_lock+0x35/0x50
[  990.013233]        [<ffffffff811340e5>] reiserfs_prepare_write+0x45/0x180
[  990.013233]        [<ffffffff81158bb6>] reiserfs_xattr_set_handle+0x2a6/0x470
[  990.013233]        [<ffffffff81158e30>] reiserfs_xattr_set+0xb0/0x150
[  990.013233]        [<ffffffff8115a6aa>] user_set+0x8a/0x90
[  990.013233]        [<ffffffff8115901a>] reiserfs_setxattr+0xaa/0xb0
[  990.013233]        [<ffffffff810e2596>] __vfs_setxattr_noperm+0x36/0xa0
[  990.013233]        [<ffffffff810e26bc>] vfs_setxattr+0xbc/0xc0
[  990.013233]        [<ffffffff810e2780>] setxattr+0xc0/0x150
[  990.013233]        [<ffffffff810e289d>] sys_fsetxattr+0x8d/0xa0
[  990.013233]        [<ffffffff81002dab>] system_call_fastpath+0x16/0x1b
[  990.013233]
[  990.013233] other info that might help us debug this:
[  990.013233]
[  990.013233] 2 locks held by dbench/1891:
[  990.013233]  #0:  (&sb->s_type->i_mutex_key#12){+.+.+.}, at: [<ffffffff810e2678>] vfs_setxattr+0x78/0xc0
[  990.013233]  #1:  (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}, at: [<ffffffff8115899a>] reiserfs_xattr_set_handle+0x8a/0x470
[  990.013233]
[  990.013233] stack backtrace:
[  990.013233] Pid: 1891, comm: dbench Not tainted 2.6.33-rc1 #1
[  990.013233] Call Trace:
[  990.013233]  [<ffffffff81061639>] print_circular_bug+0xe9/0xf0
[  990.013233]  [<ffffffff81063e30>] __lock_acquire+0x12d0/0x1560
[  990.013233]  [<ffffffff8115899a>] ? reiserfs_xattr_set_handle+0x8a/0x470
[  990.013233]  [<ffffffff8106414f>] lock_acquire+0x8f/0xb0
[  990.013233]  [<ffffffff81159505>] ? reiserfs_write_lock+0x35/0x50
[  990.013233]  [<ffffffff8115899a>] ? reiserfs_xattr_set_handle+0x8a/0x470
[  990.013233]  [<ffffffff814aba77>] __mutex_lock_common+0x47/0x3b0
[  990.013233]  [<ffffffff81159505>] ? reiserfs_write_lock+0x35/0x50
[  990.013233]  [<ffffffff81159505>] ? reiserfs_write_lock+0x35/0x50
[  990.013233]  [<ffffffff81062592>] ? mark_held_locks+0x72/0xa0
[  990.013233]  [<ffffffff814ab81d>] ? __mutex_unlock_slowpath+0xbd/0x140
[  990.013233]  [<ffffffff810628ad>] ? trace_hardirqs_on_caller+0x14d/0x1a0
[  990.013233]  [<ffffffff814abebe>] mutex_lock_nested+0x3e/0x50
[  990.013233]  [<ffffffff81159505>] reiserfs_write_lock+0x35/0x50
[  990.013233]  [<ffffffff811340e5>] reiserfs_prepare_write+0x45/0x180
[  990.013233]  [<ffffffff81158bb6>] reiserfs_xattr_set_handle+0x2a6/0x470
[  990.013233]  [<ffffffff81158e30>] reiserfs_xattr_set+0xb0/0x150
[  990.013233]  [<ffffffff814abcb4>] ? __mutex_lock_common+0x284/0x3b0
[  990.013233]  [<ffffffff8115a6aa>] user_set+0x8a/0x90
[  990.013233]  [<ffffffff8115901a>] reiserfs_setxattr+0xaa/0xb0
[  990.013233]  [<ffffffff810e2596>] __vfs_setxattr_noperm+0x36/0xa0
[  990.013233]  [<ffffffff810e26bc>] vfs_setxattr+0xbc/0xc0
[  990.013233]  [<ffffffff810e2780>] setxattr+0xc0/0x150
[  990.013233]  [<ffffffff81056018>] ? sched_clock_cpu+0xb8/0x100
[  990.013233]  [<ffffffff8105eded>] ? trace_hardirqs_off+0xd/0x10
[  990.013233]  [<ffffffff810560a3>] ? cpu_clock+0x43/0x50
[  990.013233]  [<ffffffff810c6820>] ? fget+0xb0/0x110
[  990.013233]  [<ffffffff810c6770>] ? fget+0x0/0x110
[  990.013233]  [<ffffffff81002ddc>] ? sysret_check+0x27/0x62
[  990.013233]  [<ffffffff810e289d>] sys_fsetxattr+0x8d/0xa0
[  990.013233]  [<ffffffff81002dab>] system_call_fastpath+0x16/0x1b

Reported-and-tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02 01:54:04 +01:00
Frederic Weisbecker
47376ceba5 reiserfs: Fix reiserfs lock <-> inode mutex dependency inversion
The reiserfs lock -> inode mutex dependency gets inverted when we
relax the lock while walking to the tree.

To fix this, use a specialized version of reiserfs_mutex_lock_safe
that takes care of mutex subclasses. Then we can grab the inode
mutex with I_MUTEX_XATTR subclass without any reiserfs lock
dependency.

This fixes the following report:

[ INFO: possible circular locking dependency detected ]
2.6.32-06793-gf405425-dirty #2
-------------------------------------------------------
mv/18566 is trying to acquire lock:
 (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1110708>] reiserfs_write_lock+0x28=
/0x40

but task is already holding lock:
 (&sb->s_type->i_mutex_key#5/3){+.+.+.}, at: [<c111033c>]
reiserfs_for_each_xattr+0x10c/0x380

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#5/3){+.+.+.}:
       [<c104f723>] validate_chain+0xa23/0xf70
       [<c1050155>] __lock_acquire+0x4e5/0xa70
       [<c105075a>] lock_acquire+0x7a/0xa0
       [<c134c76f>] mutex_lock_nested+0x5f/0x2b0
       [<c11102b4>] reiserfs_for_each_xattr+0x84/0x380
       [<c1110615>] reiserfs_delete_xattrs+0x15/0x50
       [<c10ef57f>] reiserfs_delete_inode+0x8f/0x140
       [<c10a565c>] generic_delete_inode+0x9c/0x150
       [<c10a574d>] generic_drop_inode+0x3d/0x60
       [<c10a4667>] iput+0x47/0x50
       [<c109cc0b>] do_unlinkat+0xdb/0x160
       [<c109cca0>] sys_unlink+0x10/0x20
       [<c1002c50>] sysenter_do_call+0x12/0x36

-> #0 (&REISERFS_SB(s)->lock){+.+.+.}:
       [<c104fc68>] validate_chain+0xf68/0xf70
       [<c1050155>] __lock_acquire+0x4e5/0xa70
       [<c105075a>] lock_acquire+0x7a/0xa0
       [<c134c76f>] mutex_lock_nested+0x5f/0x2b0
       [<c1110708>] reiserfs_write_lock+0x28/0x40
       [<c1103d6b>] search_by_key+0x1f7b/0x21b0
       [<c10e73ef>] search_by_entry_key+0x1f/0x3b0
       [<c10e77f7>] reiserfs_find_entry+0x77/0x400
       [<c10e81e5>] reiserfs_lookup+0x85/0x130
       [<c109a144>] __lookup_hash+0xb4/0x110
       [<c109b763>] lookup_one_len+0xb3/0x100
       [<c1110350>] reiserfs_for_each_xattr+0x120/0x380
       [<c1110615>] reiserfs_delete_xattrs+0x15/0x50
       [<c10ef57f>] reiserfs_delete_inode+0x8f/0x140
       [<c10a565c>] generic_delete_inode+0x9c/0x150
       [<c10a574d>] generic_drop_inode+0x3d/0x60
       [<c10a4667>] iput+0x47/0x50
       [<c10a1c4f>] dentry_iput+0x6f/0xf0
       [<c10a1d74>] d_kill+0x24/0x50
       [<c10a396b>] dput+0x5b/0x120
       [<c109ca89>] sys_renameat+0x1b9/0x230
       [<c109cb28>] sys_rename+0x28/0x30
       [<c1002c50>] sysenter_do_call+0x12/0x36

other info that might help us debug this:

2 locks held by mv/18566:
 #0:  (&sb->s_type->i_mutex_key#5/1){+.+.+.}, at: [<c109b6ac>]
lock_rename+0xcc/0xd0
 #1:  (&sb->s_type->i_mutex_key#5/3){+.+.+.}, at: [<c111033c>]
reiserfs_for_each_xattr+0x10c/0x380

stack backtrace:
Pid: 18566, comm: mv Tainted: G         C 2.6.32-06793-gf405425-dirty #2
Call Trace:
 [<c134b252>] ? printk+0x18/0x1e
 [<c104e790>] print_circular_bug+0xc0/0xd0
 [<c104fc68>] validate_chain+0xf68/0xf70
 [<c104c8cb>] ? trace_hardirqs_off+0xb/0x10
 [<c1050155>] __lock_acquire+0x4e5/0xa70
 [<c105075a>] lock_acquire+0x7a/0xa0
 [<c1110708>] ? reiserfs_write_lock+0x28/0x40
 [<c134c76f>] mutex_lock_nested+0x5f/0x2b0
 [<c1110708>] ? reiserfs_write_lock+0x28/0x40
 [<c1110708>] ? reiserfs_write_lock+0x28/0x40
 [<c134b60a>] ? schedule+0x27a/0x440
 [<c1110708>] reiserfs_write_lock+0x28/0x40
 [<c1103d6b>] search_by_key+0x1f7b/0x21b0
 [<c1050176>] ? __lock_acquire+0x506/0xa70
 [<c1051267>] ? lock_release_non_nested+0x1e7/0x340
 [<c1110708>] ? reiserfs_write_lock+0x28/0x40
 [<c104e354>] ? trace_hardirqs_on_caller+0x124/0x170
 [<c104e3ab>] ? trace_hardirqs_on+0xb/0x10
 [<c1042a55>] ? T.316+0x15/0x1a0
 [<c1042d2d>] ? sched_clock_cpu+0x9d/0x100
 [<c10e73ef>] search_by_entry_key+0x1f/0x3b0
 [<c134bf2a>] ? __mutex_unlock_slowpath+0x9a/0x120
 [<c104e354>] ? trace_hardirqs_on_caller+0x124/0x170
 [<c10e77f7>] reiserfs_find_entry+0x77/0x400
 [<c10e81e5>] reiserfs_lookup+0x85/0x130
 [<c1042d2d>] ? sched_clock_cpu+0x9d/0x100
 [<c109a144>] __lookup_hash+0xb4/0x110
 [<c109b763>] lookup_one_len+0xb3/0x100
 [<c1110350>] reiserfs_for_each_xattr+0x120/0x380
 [<c110ffe0>] ? delete_one_xattr+0x0/0x1c0
 [<c1003342>] ? math_error+0x22/0x150
 [<c1110708>] ? reiserfs_write_lock+0x28/0x40
 [<c1110615>] reiserfs_delete_xattrs+0x15/0x50
 [<c1110708>] ? reiserfs_write_lock+0x28/0x40
 [<c10ef57f>] reiserfs_delete_inode+0x8f/0x140
 [<c10a561f>] ? generic_delete_inode+0x5f/0x150
 [<c10ef4f0>] ? reiserfs_delete_inode+0x0/0x140
 [<c10a565c>] generic_delete_inode+0x9c/0x150
 [<c10a574d>] generic_drop_inode+0x3d/0x60
 [<c10a4667>] iput+0x47/0x50
 [<c10a1c4f>] dentry_iput+0x6f/0xf0
 [<c10a1d74>] d_kill+0x24/0x50
 [<c10a396b>] dput+0x5b/0x120
 [<c109ca89>] sys_renameat+0x1b9/0x230
 [<c1042d2d>] ? sched_clock_cpu+0x9d/0x100
 [<c104c8cb>] ? trace_hardirqs_off+0xb/0x10
 [<c1042dde>] ? cpu_clock+0x4e/0x60
 [<c1350825>] ? do_page_fault+0x155/0x370
 [<c1041816>] ? up_read+0x16/0x30
 [<c1350825>] ? do_page_fault+0x155/0x370
 [<c109cb28>] sys_rename+0x28/0x30
 [<c1002c50>] sysenter_do_call+0x12/0x36

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
2009-12-16 23:25:50 +01:00
Christoph Hellwig
431547b3c4 sanitize xattr handler prototypes
Add a flags argument to struct xattr_handler and pass it to all xattr
handler methods.  This allows using the same methods for multiple
handlers, e.g. for the ACL methods which perform exactly the same action
for the access and default ACLs, just using a different underlying
attribute.  With a little more groundwork it'll also allow sharing the
methods for the regular user/trusted/secure handlers in extN, ocfs2 and
jffs2 like it's already done for xfs in this patch.

Also change the inode argument to the handlers to a dentry to allow
using the handlers mechnism for filesystems that require it later,
e.g. cifs.

[with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16 12:16:49 -05:00
Frederic Weisbecker
ae635c0bbd kill-the-bkl/reiserfs: fix "reiserfs lock" / "inode mutex" lock inversion dependency
reiserfs_xattr_init is called with the reiserfs write lock held, but
if the ".reiserfs_priv" entry is not created, we take the superblock
root directory inode mutex until .reiserfs_priv is created.

This creates a lock dependency inversion against other sites such as
reiserfs_file_release() which takes an inode mutex and the reiserfs
lock after.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-14 07:18:26 +02:00
Frederic Weisbecker
c72e05756b kill-the-bkl/reiserfs: acquire the inode mutex safely
While searching a pathname, an inode mutex can be acquired
in do_lookup() which calls reiserfs_lookup() which in turn
acquires the write lock.

On the other side reiserfs_fill_super() can acquire the write_lock
and then call reiserfs_lookup_privroot() which can acquire an
inode mutex (the root of the mount point).

So we theoretically risk an AB - BA lock inversion that could lead
to a deadlock.

As for other lock dependencies found since the bkl to mutex
conversion, the fix is to use reiserfs_mutex_lock_safe() which
drops the lock dependency to the write lock.

[ Impact: fix a possible deadlock with reiserfs ]

Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14 07:18:24 +02:00
Alexey Dobriyan
405f55712d headers: smp_lock.h redux
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-12 12:22:34 -07:00
Jeff Mahoney
73422811d2 reiserfs: allow exposing privroot w/ xattrs enabled
This patch adds an -oexpose_privroot option to allow access to the privroot.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:35:58 -04:00
Jeff Mahoney
b83674c0da reiserfs: fixup perms when xattrs are disabled
This adds CONFIG_REISERFS_FS_XATTR protection from reiserfs_permission.

This is needed to avoid warnings during file deletions and chowns with
xattrs disabled.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-17 11:45:45 -07:00
Jeff Mahoney
ceb5edc457 reiserfs: deal with NULL xattr root w/ xattrs disabled
This avoids an Oops in open_xa_root that can occur when deleting a file
with xattrs disabled.  It assumes that the xattr root will be there, and
that is not guaranteed.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-17 11:45:45 -07:00
Jeff Mahoney
12abb35a03 reiserfs: clean up ifdefs
With xattr cleanup even with xattrs disabled, much of the initial setup
is still performed.  Some #ifdefs are just not needed since the options
they protect wouldn't be available anyway.

This cleans those up.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-17 11:45:45 -07:00
Jeff Mahoney
677c9b2e39 reiserfs: remove privroot hiding in lookup
With Al Viro's patch to move privroot lookup to fs mount, there's no need
 to have special code to hide the privroot in reiserfs_lookup.

 I've also cleaned up the privroot hiding in reiserfs_readdir_dentry and
 removed the last user of reiserfs_xattrs().

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:49:39 -04:00
Jeff Mahoney
ab17c4f021 reiserfs: fixup xattr_root caching
The xattr_root caching was broken from my previous patch set. It wouldn't
 cause corruption, but could cause decreased performance due to allocating
 a larger chunk of the journal (~ 27 blocks) than it would actually use.

 This patch loads the xattr root dentry at xattr initialization and creates
 it on-demand. Since we're using the cached dentry, there's no point
 in keeping lookup_or_create_dir around, so that's removed.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:49:39 -04:00
Al Viro
edcc37a047 Always lookup priv_root on reiserfs mount and keep it
... even if it's a negative dentry.  That way we can set ->d_op on
root before anyone could race with us.  Simplify d_compare(), while
we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:49:38 -04:00
Jeff Mahoney
5a6059c358 reiserfs: Expand i_mutex to enclose lookup_one_len
2.6.30-rc3 introduced some sanity checks in the VFS code to avoid NFS
 bugs by ensuring that lookup_one_len is always called under i_mutex.

 This patch expands the i_mutex locking to enclose lookup_one_len. This was
 always required, but not not enforced in the reiserfs code since it
 does locking around the xattr interactions with the xattr_sem.

 This is obvious enough, and it survived an overnight 50 thread ACL test.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:49:38 -04:00
Jeff Mahoney
3a355cc61d reiserfs: xattr_create is unused with xattrs disabled
This patch ifdefs xattr_create when xattrs aren't enabled.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 14:28:58 -07:00
Linus Torvalds
e1c5024828 Merge branch 'reiserfs-updates' from Jeff Mahoney
* reiserfs-updates: (35 commits)
  reiserfs: rename [cn]_* variables
  reiserfs: rename p_._ variables
  reiserfs: rename p_s_tb to tb
  reiserfs: rename p_s_inode to inode
  reiserfs: rename p_s_bh to bh
  reiserfs: rename p_s_sb to sb
  reiserfs: strip trailing whitespace
  reiserfs: cleanup path functions
  reiserfs: factor out buffer_info initialization
  reiserfs: add atomic addition of selinux attributes during inode creation
  reiserfs: use generic readdir for operations across all xattrs
  reiserfs: journaled xattrs
  reiserfs: use generic xattr handlers
  reiserfs: remove i_has_xattr_dir
  reiserfs: make per-inode xattr locking more fine grained
  reiserfs: eliminate per-super xattr lock
  reiserfs: simplify xattr internal file lookups/opens
  reiserfs: Clean up xattrs when REISERFS_FS_XATTR is unset
  reiserfs: remove IS_PRIVATE helpers
  reiserfs: remove link detection code
  ...

Fixed up conflicts manually due to:
 - quota name cleanups vs variable naming changes:
	fs/reiserfs/inode.c
	fs/reiserfs/namei.c
	fs/reiserfs/stree.c
        fs/reiserfs/xattr.c
 - exported include header cleanups
	include/linux/reiserfs_fs.h
2009-03-30 12:33:01 -07:00
Jeff Mahoney
a41f1a4715 reiserfs: use generic readdir for operations across all xattrs
The current reiserfs xattr implementation open codes reiserfs_readdir
and frees the path before calling the filldir function.  Typically, the
filldir function is something that modifies the file system, such as a
chown or an inode deletion that also require reading of an inode
associated with each direntry.  Since the file system is modified, the
path retained becomes invalid for the next run.  In addition, it runs
backwards in attempt to minimize activity.

This is clearly suboptimal from a code cleanliness perspective as well
as performance-wise.

This patch implements a generic reiserfs_for_each_xattr that uses the
generic readdir and a specific filldir routine that simply populates an
array of dentries and then performs a specific operation on them.  When
all files have been operated on, it then calls the operation on the
directory itself.

The result is a noticable code reduction and better performance.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:38 -07:00
Jeff Mahoney
0ab2621ebd reiserfs: journaled xattrs
Deadlocks are possible in the xattr code between the journal lock and the
xattr sems.

This patch implements journalling for xattr operations. The benefit is
twofold:
 * It gets rid of the deadlock possibility by always ensuring that xattr
   write operations are initiated inside a transaction.
 * It corrects the problem where xattr backing files aren't considered any
   differently than normal files, despite the fact they are metadata.

I discussed the added journal load with Chris Mason, and we decided that
since xattrs (versus other journal activity) is fairly rare, the introduction
of larger transactions to support journaled xattrs wouldn't be too big a deal.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:38 -07:00
Jeff Mahoney
48b32a3553 reiserfs: use generic xattr handlers
Christoph Hellwig had asked me quite some time ago to port the reiserfs
xattrs to the generic xattr interface.

This patch replaces the reiserfs-specific xattr handling code with the
generic struct xattr_handler.

However, since reiserfs doesn't split the prefix and name when accessing
xattrs, it can't leverage generic_{set,get,list,remove}xattr without
needlessly reconstructing the name on the back end.

Update 7/26/07: Added missing dput() to deletion path.
Update 8/30/07: Added missing mark_inode_dirty when i_mode is used to
                represent an ACL and no previous ACL existed.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:38 -07:00
Jeff Mahoney
8ecbe550a1 reiserfs: remove i_has_xattr_dir
With the changes to xattr root locking, the i_has_xattr_dir flag
is no longer needed. This patch removes it.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:38 -07:00
Jeff Mahoney
8b6dd72a44 reiserfs: make per-inode xattr locking more fine grained
The per-inode locking can be made more fine-grained to surround just the
interaction with the filesystem itself.  This really only applies to
protecting reads during a write, since concurrent writes are barred with
inode->i_mutex at the vfs level.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:38 -07:00
Jeff Mahoney
d984561b32 reiserfs: eliminate per-super xattr lock
With the switch to using inode->i_mutex locking during lookups/creation
in the xattr root, the per-super xattr lock is no longer needed.

This patch removes it.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:38 -07:00
Jeff Mahoney
6c17675e1e reiserfs: simplify xattr internal file lookups/opens
The xattr file open/lookup code is needlessly complex.  We can use
vfs-level operations to perform the same work, and also simplify the
locking constraints.  The locking advantages will be exploited in future
patches.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:37 -07:00
Jeff Mahoney
a72bdb1cd2 reiserfs: Clean up xattrs when REISERFS_FS_XATTR is unset
The current reiserfs xattr implementation will not clean up old xattr
files if files are deleted when REISERFS_FS_XATTR is unset.  This
results in inaccessible lost files, wasting space.

This patch compiles in basic xattr knowledge, such as how to delete them
and change ownership for quota tracking.  If the file system has never
used xattrs, then the operation is quite fast: it returns immediately
when it sees there is no .reiserfs_priv directory.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:37 -07:00
Jeff Mahoney
6dfede6963 reiserfs: remove IS_PRIVATE helpers
There are a number of helper functions for marking a reiserfs inode
private that were leftover from reiserfs did its own thing wrt to
private inodes.  S_PRIVATE has been in the kernel for some time, so this
patch removes the helpers and uses IS_PRIVATE instead.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:37 -07:00
Jeff Mahoney
010f5a21a3 reiserfs: remove link detection code
Early in the reiserfs xattr development, there was a plan to use
hardlinks to save disk space for identical xattrs.  That code never
materialized and isn't going to, so this patch removes the detection
code.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:37 -07:00
Jeff Mahoney
ec6ea56b2f reiserfs: xattr reiserfs_get_page takes offset instead of index
This patch changes reiserfs_get_page to take an offset rather than an
index since no callers calculate the index differently.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:37 -07:00
Jeff Mahoney
f437c529e3 reiserfs: small variable cleanup
This patch removes the xinode and mapping variables from
reiserfs_xattr_{get,set}.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:37 -07:00
Jeff Mahoney
0030b64570 reiserfs: use reiserfs_error()
This patch makes many paths that are currently using warnings to handle
the error.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:37 -07:00
Jeff Mahoney
45b03d5e8e reiserfs: rework reiserfs_warning
ReiserFS warnings can be somewhat inconsistent.
In some cases:
 * a unique identifier may be associated with it
 * the function name may be included
 * the device may be printed separately

This patch aims to make warnings more consistent. reiserfs_warning() prints
the device name, so printing it a second time is not required. The function
name for a warning is always helpful in debugging, so it is now automatically
inserted into the output. Hans has stated that every warning should have
a unique identifier. Some cases lack them, others really shouldn't have them.
reiserfs_warning() now expects an id associated with each message. In the
rare case where one isn't needed, "" will suffice.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:36 -07:00
Jeff Mahoney
1d889d9958 reiserfs: make some warnings informational
In several places, reiserfs_warning is used when there is no warning, just
a notice. This patch changes some of them to indicate that the message
is merely informational.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:35 -07:00
Al Viro
e16404ed0f constify dentry_operations: misc filesystems
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:44:00 -04:00
Julien Brunel
67b172c097 fs/reiserfs: use an IS_ERR test rather than a NULL test
In case of error, the function open_xa_dir returns an ERR pointer, but
never returns a NULL pointer.  So a NULL test that comes after an IS_ERR
test should be deleted.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@match_bad_null_test@
expression x, E;
statement S1,S2;
@@
x = open_xa_dir(...)
... when != x = E
(
*  if (x == NULL && ...) S1 else S2
|
*  if (x == NULL || ...) S1 else S2
)
// </smpl>

Signed-off-by: Julien Brunel <brunel@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:46 -07:00