journal_end doesn't need a separate sb argument; it's provided by the
transaction handle.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NJan Kara <jack@suse.cz>

journal_end takes a block count argument but doesn't actually use it
for anything. We can remove it.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NJan Kara <jack@suse.cz>

This patch reformats comments in the reiserfs code to fit in 80 columns and
to follow the style rules.

There is no functional change but it helps make my eyes bleed less.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NJan Kara <jack@suse.cz>

This patch does a quick search and replace:
B_N_PITEM_HEAD() -> item_head()
B_N_PDELIM_KEY() -> internal_key()
B_N_PKEY() -> leaf_key()
B_N_PITEM() -> item_body()

And the item_head version:
B_I_PITEM() -> ih_item_body()
I_ENTRY_COUNT() -> ih_entry_count()

And the treepath variants:
get_ih() -> tp_item_head()
PATH_PITEM_HEAD() -> tp_item_head()
get_item() -> tp_item_body()

... which makes the code much easier on the eyes.

I've also removed a few unused macros.

Checkpatch will complain about the 80 character limit for do_balan.c.
I've addressed that in a later patchset to split up balance_leaf().
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NJan Kara <jack@suse.cz>

The reiserfs write lock hasn't been the BKL for some time. There's no
need to have different file systems queued up on the same workqueue.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NJan Kara <jack@suse.cz>

Move prototype declaration to header file reiserfs/reiserfs.h from
reiserfs/super.c because they are used by more than one file.

This eliminates the following warning in reiserfs/bitmap.c:

  fs/reiserfs/bitmap.c:647:6: warning: no previous prototype for `show_alloc_options' [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Acked-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

it's never called with NULL argument...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Now that the definition is centralized in <linux/kernel.h>, the
definitions of U32_MAX (and related) elsewhere in the kernel can be
removed.
Signed-off-by: NAlex Elder <elder@linaro.org>
Acked-by: NSage Weil <sage@inktank.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The symbol U32_MAX is defined in several spots.  Change these
definitions to be conditional.  This is in preparation for the next
patch, which centralizes the definition in <linux/kernel.h>.
Signed-off-by: NAlex Elder <elder@linaro.org>
Cc: Sage Weil <sage@inktank.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The reiserfs write lock replaced the BKL and uses similar semantics.

Frederic's locking code makes a distinction between when the lock is nested
and when it's being acquired/released, but I don't think that's the right
distinction to make.

The right distinction is between the lock being released at end-of-use and
the lock being released for a schedule. The unlock should return the depth
and the lock should restore it, rather than the other way around as it is now.

This patch implements that and adds a number of places where the lock
should be dropped.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>

... and clean the callers up a bit
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed vmtruncate
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch stops reiserfs using the VFS 'write_super()' method along with the
s_dirt flag, because they are on their way out.

The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblock using the '->write_super()' call-back.  But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Turn 'reiserfs_flush_old_commits()' into a void function because the callers
do not cares about what it returns anyway.

We are going to remove the 'sb->s_dirt' field completely and this patch is a
small step towards this direction.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

pass inode + parent's inode or NULL instead of dentry + bool saying
whether we want the parent or not.

NOTE: that needs ceph fix folded in.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including <linux/bug.h> and not just
expecting it to be implicitly present.

We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Make reiserfs properly display mount options in /proc/mounts.

CC: reiserfs-devel@vger.kernel.org
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Using __test_and_{set,clear}_bit_le() with ignoring its return value can
be replaced with __{set,clear}_bit_le().

This introduces reiserfs_{set,clear}_le_bit for __{set,clear}_bit_le and
does the above change with them.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

As a preparation for removing ext2 non-atomic bit operations from
asm/bitops.h.  This converts ext2 non-atomic bit operations to
little-endian bit operations.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Fix trivial typo in code comment (change adn for and), also change comment
style for proper coding style.
Signed-off-by: NDavidlohr Bueso <dave@gnu.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This gives the filesystem more information about the writeback that
is happening.  Trond requested this for the NFS unstable write handling,
and other filesystems might benefit from this too by beeing able to
distinguish between the different callers in more detail.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When we relax the reiserfs lock to avoid creating unwanted
dependencies against others locks while grabbing these,
we want to ensure it has not been taken recursively, otherwise
the lock won't be really relaxed. Only its depth will be decreased.
The unwanted dependency would then actually happen.

To prevent from that, add a reiserfs_lock_check_recursive() call
in the places that need it.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>

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: NChristian Kujau <lists@nerdbynature.de>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>

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-gf4054253-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-gf4054253-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: NAlexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>

* small define cleanup in header
* fix #ifdeffery in procfs.c via Kconfig
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

/proc/fs/reiserfs/version is on the way of removing ->read_proc interface.
 It's empty however, so simply remove it instead of doing dummy
conversion.  It's hard to see what information userspace can extract from
empty file.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The reiserfs ioctl path doesn't need the big kernel lock anymore , now
that the filesystem synchronizes through its own lock.

We can then turn reiserfs_ioctl() into an unlocked_ioctl callback.
Signed-off-by: NFrederic 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>
Cc: Thomas Gleixner <tglx@linutronix.de>

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: NFrederic Weisbecker <fweisbec@gmail.com>

The goal of fs_changed() is to check whether the tree changed during a
schedule(). This is a BKL legacy.

A recent patch added an explicit unconditional release/reacquire of the
write lock around the cond_resched() called inside fs_changed.

But it's wasteful to unconditionally do that, we are creating superfluous
lock contention in !TIF_NEED_RESCHED case.

This patch manage that by calling reiserfs_cond_resched() from fs_changed()
which only releases the lock if we are going to reschedule.

[ Impact: inject less lock contention and tree job retries ]

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: NFrederic Weisbecker <fweisbec@gmail.com>

Usually, when we call cond_resched(), we want the write lock
to be released and then reacquired once we return from scheduling.
Not only does it follow the previous bkl based locking scheme, but
it also let other waiters to get the lock.

But if we aren't going to reschedule(), such as in !TIF_NEED_RESCHED
case, it's useless to release the lock. Worse, if we release and reacquire
the lock whereas it is not needed, we create useless contentions. Also
if someone takes the lock while we are modifying or reading the tree,
there are good chances we'll have to retry our operation, eg if the
block we were seeeking has moved.

So this patch introduces a helper which only unlock the write lock
if we are going to schedule.

[ Impact: prepare to inject less lock contention and less tree operation attempts ]
Reported-by: NAndi Kleen <andi@firstfloor.org>
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: NFrederic Weisbecker <fweisbec@gmail.com>

fs_changed() is a macro used by reiserfs to check whether its tree has been
rebalanced. It has been designed to check parallel changes on the tree after
calling a sleeping function, which released the Bkl.

fs_changed() also calls cond_resched(), so that if rescheduling is needed,
we are in the best place to do that, since we check if the tree has changed
just after (because of the bkl release on schedule()).

Even if we are not anymore using the Bkl, we still want to release the lock
while we reschedule, so that other waiters for the lock can acquire it safely,
because of the following __fs_changed() check.

[ Impact: release the reiserfs write lock when it is not needed ]

Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

Sometimes we don't want to recursively hold the per superblock write
lock because we want to be sure it is actually released when we come
to sleep.

This patch introduces the necessary tools for that.

reiserfs_write_lock_once() does the same job than reiserfs_write_lock()
except that it won't try to acquire recursively the lock if the current
task already owns it. Also the lock_depth before the call of this function
is returned.

reiserfs_write_unlock_once() unlock only if reiserfs_write_lock_once()
returned a depth equal to -1, ie: only if it actually locked.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@texware.it>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
LKML-Reference: <1239680065-25013-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>