Commit Graph

396 Commits

Author SHA1 Message Date
Frederic Weisbecker 48f6ba5e69 kill-the-bkl/reiserfs: fix reiserfs lock to cpu_add_remove_lock dependency
While creating the reiserfs workqueue during the journal
initialization, we are holding the reiserfs lock, but
create_workqueue() also holds the cpu_add_remove_lock, creating
then the following dependency:

- reiserfs lock -> cpu_add_remove_lock

But we also have the following existing dependencies:

- mm->mmap_sem -> reiserfs lock
- cpu_add_remove_lock -> cpu_hotplug.lock -> slub_lock -> sysfs_mutex

The merged dependency chain then becomes:

- mm->mmap_sem -> reiserfs lock -> cpu_add_remove_lock ->
	cpu_hotplug.lock -> slub_lock -> sysfs_mutex

But when we fill a dir entry in sysfs_readir(), we are holding the
sysfs_mutex and we also might fault while copying the directory entry
to the user, leading to the following dependency:

- sysfs_mutex -> mm->mmap_sem

The end result is then a lock inversion between sysfs_mutex and
mm->mmap_sem, as reported in the following lockdep warning:

[ INFO: possible circular locking dependency detected ]
2.6.31-07095-g25a3912 #4
-------------------------------------------------------
udevadm/790 is trying to acquire lock:
 (&mm->mmap_sem){++++++}, at: [<c1098942>] might_fault+0x72/0xc0

but task is already holding lock:
 (sysfs_mutex){+.+.+.}, at: [<c110813c>] sysfs_readdir+0x7c/0x260

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #5 (sysfs_mutex){+.+.+.}:
      [...]

-> #4 (slub_lock){+++++.}:
      [...]

-> #3 (cpu_hotplug.lock){+.+.+.}:
      [...]

-> #2 (cpu_add_remove_lock){+.+.+.}:
      [...]

-> #1 (&REISERFS_SB(s)->lock){+.+.+.}:
      [...]

-> #0 (&mm->mmap_sem){++++++}:
      [...]

This can be fixed by relaxing the reiserfs lock while creating the
workqueue.
This is fine to relax the lock here, we just keep it around to pass
through reiserfs lock checks and for paranoid reasons.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Tested-by: Alexander Beregalov <a.beregalov@gmail.com>
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>
2009-10-05 16:31:37 +02:00
Alexey Dobriyan 0d54b217a2 const: make struct super_block::s_qcop const
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:24 -07:00
Alexey Dobriyan 61e225dc34 const: make struct super_block::dq_op const
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:24 -07:00
Frederic Weisbecker 193be0ee17 kill-the-bkl/reiserfs: Fix induced mm->mmap_sem to sysfs_mutex dependency
Alexander Beregalov reported the following warning:

	=======================================================
	[ INFO: possible circular locking dependency detected ]
	2.6.31-03149-gdcc030a #1
	-------------------------------------------------------
	udevadm/716 is trying to acquire lock:
	 (&mm->mmap_sem){++++++}, at: [<c107249a>] might_fault+0x4a/0xa0

	but task is already holding lock:
	 (sysfs_mutex){+.+.+.}, at: [<c10cb9aa>] sysfs_readdir+0x5a/0x200

	which lock already depends on the new lock.

	the existing dependency chain (in reverse order) is:

	-> #3 (sysfs_mutex){+.+.+.}:
	       [...]

	-> #2 (&bdev->bd_mutex){+.+.+.}:
	       [...]

	-> #1 (&REISERFS_SB(s)->lock){+.+.+.}:
	       [...]

	-> #0 (&mm->mmap_sem){++++++}:
	       [...]

On reiserfs mount path, we take the reiserfs lock and while
initializing the journal, we open the device, taking the
bdev->bd_mutex. Then rescan_partition() may signal the change
to sysfs.

We have then the following dependency:

	reiserfs_lock -> bd_mutex -> sysfs_mutex

Later, while entering reiserfs_readpage() after a pagefault in an
mmaped reiserfs file, we are holding the mm->mmap_sem, and we are going
to take the reiserfs lock too.
We have then the following dependency:

	mm->mmap_sem -> reiserfs_lock

which, expanded with the previous dependency gives us:

	mm->mmap_sem -> reiserfs_lock -> bd_mutex -> sysfs_mutex

Now while entering the sysfs readdir path, we are holding the
sysfs_mutex. And when we copy a directory entry to the user buffer, we
might fault and then take the mm->mmap_sem lock. Which leads to the
circular locking dependency reported.

We can fix that by relaxing the reiserfs lock during the call to
journal_init_dev(), which is the place where we open the mounted
device.

This is fine to relax the lock here because we are in the begining of
the reiserfs mount path and there is nothing to protect at this time,
the journal is not intialized.
We just keep this lock around for paranoid reasons.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Tested-by: Alexander Beregalov <a.beregalov@gmail.com>
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>
2009-09-17 05:31:37 +02:00
Frederic Weisbecker 8050318598 kill-the-bkl/reiserfs: panic in case of lock imbalance
Until now, trying to unlock the reiserfs write lock whereas the current
task doesn't hold it lead to a simple warning.
We should actually warn and panic in this case to avoid the user datas
to reach an unstable state.

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 07:18:30 +02:00
Frederic Weisbecker 7e94277050 kill-the-bkl/reiserfs: fix recursive reiserfs write lock in reiserfs_commit_write()
reiserfs_commit_write() is always called with the write lock held.
Thus the current calls to reiserfs_write_lock() in this function are
acquiring the lock recursively.
We can safely drop them.

This also solves further assumptions for this lock to be really
released while calling reiserfs_write_unlock().

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 07:18:29 +02:00
Frederic Weisbecker b10ab4c337 kill-the-bkl/reiserfs: fix recursive reiserfs lock in reiserfs_mkdir()
reiserfs_mkdir() acquires the reiserfs lock, assuming it has been called
from the dir inodes callbacks, without the lock held.

But it can also be called from other internal sites such as
reiserfs_xattr_init() which already holds the lock. This recursive
locking leads to further wrong assumptions. For example, later calls
to reiserfs_mutex_lock_safe() won't actually unlock the reiserfs lock
the time we acquire a given mutex, creating unexpected lock inversions.

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 07:18:27 +02:00
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 08f14fc896 kill-the-bkl/reiserfs: move the concurrent tree accesses checks per superblock
When do_balance() balances the tree, a trick is performed to
provide the ability for other tree writers/readers to check whether
do_balance() is executing concurrently (requires CONFIG_REISERFS_CHECK).

This is done to protect concurrent accesses to the tree. The trick
is the following:

When do_balance is called, a unique global variable called cur_tb
takes a pointer to the current tree to be rebalanced.
Once do_balance finishes its work, cur_tb takes the NULL value.

Then, concurrent tree readers/writers just have to check the value
of cur_tb to ensure do_balance isn't executing concurrently.
If it is, then it proves that schedule() occured on do_balance(),
which then relaxed the bkl that protected the tree.

Now that the bkl has be turned into a mutex, this check is still
fine even though do_balance() becomes preemptible: the write lock
will not be automatically released on schedule(), so the tree is
still protected.

But this is only fine if we have a single reiserfs mountpoint.
Indeed, because the bkl is a global lock, it didn't allowed
concurrent executions between a tree reader/writer in a mount point
and a do_balance() on another tree from another mountpoint.

So assuming all these readers/writers weren't supposed to be
reentrant, the current check now sometimes detect false positives with
the current per-superblock mutex which allows this reentrancy.

This patch keeps the concurrent tree accesses check but moves it
per superblock, so that only trees from a same mount point are
checked to be not accessed concurrently.

[ Impact: fix spurious panic while running several reiserfs mount-points ]

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 07:18:25 +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
Frederic Weisbecker 2ac626955e kill-the-bkl/reiserfs: unlock only when needed in search_by_key
search_by_key() is the site which most requires the lock.
This is mostly because it is a very central function and also
because it releases/reaqcuires the write lock at least once each
time it is called.

Such release/reacquire creates a lot of contention in this place and
also opens more the window which let another thread changing the tree.
When it happens, the current path searching over the tree must be
retried from the beggining (the root) which is a wasteful and
time consuming recovery.

This patch factorizes two release/reacquire sequences:

- reading leaf nodes blocks
- reading current block

The latter immediately follows the former.

The whole sequence is safe as a single unlocked section because
we check just after if the tree has changed during these operations.

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 07:18:22 +02:00
Frederic Weisbecker c63e3c0b24 kill-the-bkl/reiserfs: use mutex_lock in reiserfs_mutex_lock_safe
reiserfs_mutex_lock_safe() is a hack to avoid any dependency between
an internal reiserfs mutex and the write lock, it has been proposed
to follow the old bkl logic.

The code does the following:

while (!mutex_trylock(m)) {
	reiserfs_write_unlock(s);
	schedule();
	reiserfs_write_lock(s);
}

It then imitate the implicit behaviour of the lock when it was
a Bkl and hadn't such dependency:

mutex_lock(m) {
	if (fastpath)
		let's go
	else {
		wait_for_mutex() {
			schedule() {
				unlock_kernel()
				reacquire_lock_kernel()
			}
		}
	}
}

The problem is that by using such explicit schedule(), we don't
benefit of the adaptive mutex spinning on owner.

The logic in use now is:

reiserfs_write_unlock(s);
mutex_lock(m); // -> possible adaptive spinning
reiserfs_write_lock(s);

[ Impact: restore the use of adaptive spinning mutexes in 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 07:18:21 +02:00
Frederic Weisbecker d6f5b0aa08 kill-the-bkl/reiserfs: factorize the locking in reiserfs_write_end()
reiserfs_write_end() is a hot path in reiserfs.
We have two wasteful write lock lock/release inside that can be gathered
without changing the code logic.

This patch factorizes them out in a single protected section, reducing the
number of contentions inside.

[ Impact: reduce lock contention in a reiserfs hotpath ]

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 07:18:20 +02:00
Frederic Weisbecker 09eb47a7c5 kill-the-bkl/reiserfs: reduce number of contentions in search_by_key()
search_by_key() is a central function in reiserfs which searches
the patch in the fs tree from the root to a node given its key.

It is the function that is most requesting the write lock
because it's a path very often used.

Also we forget to release the lock while reading the next tree node,
making us holding the lock in a wasteful way.

Then we release the lock while reading the current node and its childs,
all-in-one. It should be safe because we have a reference to these
blocks and even if we read a block that will be concurrently changed,
we have an fs_changed check later that will make us retry the path from
the root.

[ Impact: release the write lock while unused in a hot path ]

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 07:18:19 +02:00
Frederic Weisbecker b1c839bb2d kill-the-bkl/reiserfs: don't hold the write recursively in reiserfs_lookup()
The write lock can be acquired recursively in reiserfs_lookup(). But we may
want to *really* release the lock before possible rescheduling from a
reiserfs_lookup() callee.

Hence we want to only acquire the lock once (ie: not recursively).

[ Impact: prevent from possible false unreleased write lock on sleeping ]

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 07:18:17 +02:00
Frederic Weisbecker 26931309a4 kill-the-bkl/reiserfs: lock only once on reiserfs_get_block()
reiserfs_get_block() is one of these sites where the write lock might
be acquired recursively.

It's a particular problem because this function is called very often.
It's a hot spot which needs to reschedule() periodically while converting
direct items to indirect ones because it can take some time.

Then if we are applying the write lock release/reacquire pattern on
schedule() here, it may not produce the desired effect since we may have
locked in more than one depth.

The solution is to use reiserfs_write_lock_once() which won't try
to reacquire the lock recursively. Then the lock will be *really*
released before schedule().

Also, we only release the lock if TIF_NEED_RESCHED is set to not
create wasteful numerous contentions.

[ Impact: fix a too long holded lock case in reiserfs_get_block() ]

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 07:18:16 +02:00
Frederic Weisbecker 6e3647acb4 kill-the-BKL/reiserfs: release the write lock on flush_commit_list()
flush_commit_list() uses ll_rw_block() to commit the pending log blocks.
ll_rw_block() might sleep, and the bkl was released at this point. Then
we can also relax the write lock at this point.

[ 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: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14 07:18:13 +02:00
Frederic Weisbecker 4c5eface5d kill-the-BKL/reiserfs: release the write lock inside reiserfs_read_bitmap_block()
reiserfs_read_bitmap_block() uses sb_bread() to read the bitmap block. This
helper might sleep.

Then, when the bkl was used, it was released at this point. We can then
relax the write lock too here.

[ 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: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14 07:18:11 +02:00
Frederic Weisbecker 148d3504c1 kill-the-BKL/reiserfs: release the write lock inside get_neighbors()
get_neighbors() is used to get the left and/or right blocks
against a given one in order to balance a tree.

sb_bread() is used to read the buffer of these neighors blocks and
while it waits for this operation, it might sleep.

The bkl was released at this point, and then we can also release
the write lock before calling sb_bread().

This is safe because if the filesystem is changed after this
lock release, the function returns REPEAT_SEARCH (aka SCHEDULE_OCCURRED
in the function header comments) in order to repeat the neighbhor
research.

[ 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: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14 07:18:10 +02:00
Frederic Weisbecker 5e69e3a449 kill-the-BKL/reiserfs: release write lock while rescheduling on prepare_for_delete_or_cut()
prepare_for_delete_or_cut() can process several types of items, including
indirect items, ie: items which contain no file data but pointers to
unformatted nodes scattering the datas of a file.

In this case it has to zero out these pointers to block numbers of
unformatted nodes and release the bitmap from these block numbers.

It can take some time, so a rescheduling() is performed between each
block processed. We can safely release the write lock while
rescheduling(), like the bkl did, because the code checks just after
if the item has moved after sleeping.

[ 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: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14 07:18:09 +02:00
Frederic Weisbecker e6950a4da3 kill-the-BKL/reiserfs: release the write lock before rescheduling on do_journal_end()
When do_journal_end() copies data to the journal blocks buffers in memory,
it reschedules if needed between each block copied and dirtyfied.

We can also release the write lock at this rescheduling stage,
like did the bkl implicitly.

[ 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: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14 07:18:08 +02:00
Frederic Weisbecker dc8f6d8936 kill-the-BKL/reiserfs: only acquire the write lock once in reiserfs_dirty_inode
Impact: fix a deadlock

reiserfs_dirty_inode() is the super_operations::dirty_inode() callback
of reiserfs. It can be called from different contexts where the write
lock can be already held.

But this function also grab the write lock (possibly recursively).
Subsequent release of the lock before sleep will actually not release
the lock if the caller of mark_inode_dirty() (which in turn calls
reiserfs_dirty_inode()) already owns the lock.

A typical case:

reiserfs_write_end() {
	acquire_write_lock()
	mark_inode_dirty() {
		reiserfs_dirty_inode() {
			reacquire_write_lock() {
				journal_begin() {
					do_journal_begin_r() {
						/*
						 * fail to release, still
						 * one depth of lock
						 */
						release_write_lock()
						reiserfs_wait_on_write_block() {
							wait_event()

The event is usually provided by something which needs the write lock but
it hasn't been released.

We use reiserfs_write_lock_once() here to ensure we only grab the
write lock in one level.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@texware.it>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
LKML-Reference: <1239680065-25013-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 07:18:04 +02:00
Frederic Weisbecker 22c963addc kill-the-BKL/reiserfs: lock only once in reiserfs_truncate_file
Impact: fix a deadlock

reiserfs_truncate_file() can be called from multiple context where
the write lock can be already hold or not.

This function also acquire (possibly recursively) the write
lock. Subsequent releases before sleeping will not actually release
the lock because we may be in more than one lock depth degree.

A typical case is:

reiserfs_file_release {
	acquire_the_lock()
	reiserfs_truncate_file()
		reacquire_the_lock()
		journal_begin() {
			do_journal_begin_r() {
				reiserfs_wait_on_write_block() {
					/*
					 * Not released because still one
					 * depth owned
					 */
					release_lock()
					wait_for_event()

At this stage the event never happen because the one which provides
it needs the write lock.

We use reiserfs_write_lock_once() here to ensure that we don't acquire the
write lock recursively.

Signed-off-by: Frederic 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: <1239680065-25013-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 07:18:03 +02:00
Frederic Weisbecker daf88c8983 kill-the-BKL/reiserfs: provide a tool to lock only once the write lock
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: Frederic 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: Ingo Molnar <mingo@elte.hu>
2009-09-14 07:18:02 +02:00
Frederic Weisbecker a412f9efdd reiserfs, kill-the-BKL: fix unsafe j_flush_mutex lock
Impact: fix a deadlock

The j_flush_mutex is acquired safely in journal.c:
if we can't take it, we free the reiserfs per superblock lock
and wait a bit.

But we have a remaining place in kupdate_transactions() where
j_flush_mutex is still acquired traditionnaly. Thus the following
scenario (warned by lockdep) can happen:

A						B

mutex_lock(&write_lock)			mutex_lock(&write_lock)
	mutex_lock(&j_flush_mutex)	mutex_lock(&j_flush_mutex) //block
	mutex_unlock(&write_lock)
	sleep...
	mutex_lock(&write_lock) //deadlock

Fix this by using reiserfs_mutex_lock_safe() in kupdate_transactions().

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@texware.it>
Cc: Jeff Mahoney <jeffm@suse.com>
LKML-Reference: <1239660635-12940-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 07:18:01 +02:00
Frederic Weisbecker 8ebc423238 reiserfs: kill-the-BKL
This patch is an attempt to remove the Bkl based locking scheme from
reiserfs and is intended.

It is a bit inspired from an old attempt by Peter Zijlstra:

   http://lkml.indiana.edu/hypermail/linux/kernel/0704.2/2174.html

The bkl is heavily used in this filesystem to prevent from
concurrent write accesses on the filesystem.

Reiserfs makes a deep use of the specific properties of the Bkl:

- It can be acqquired recursively by a same task
- It is released on the schedule() calls and reacquired when schedule() returns

The two properties above are a roadmap for the reiserfs write locking so it's
very hard to simply replace it with a common mutex.

- We need a recursive-able locking unless we want to restructure several blocks
  of the code.
- We need to identify the sites where the bkl was implictly relaxed
  (schedule, wait, sync, etc...) so that we can in turn release and
  reacquire our new lock explicitly.
  Such implicit releases of the lock are often required to let other
  resources producer/consumer do their job or we can suffer unexpected
  starvations or deadlocks.

So the new lock that replaces the bkl here is a per superblock mutex with a
specific property: it can be acquired recursively by a same task, like the
bkl.

For such purpose, we integrate a lock owner and a lock depth field on the
superblock information structure.

The first axis on this patch is to turn reiserfs_write_(un)lock() function
into a wrapper to manage this mutex. Also some explicit calls to
lock_kernel() have been converted to reiserfs_write_lock() helpers.

The second axis is to find the important blocking sites (schedule...(),
wait_on_buffer(), sync_dirty_buffer(), etc...) and then apply an explicit
release of the write lock on these locations before blocking. Then we can
safely wait for those who can give us resources or those who need some.
Typically this is a fight between the current writer, the reiserfs workqueue
(aka the async commiter) and the pdflush threads.

The third axis is a consequence of the second. The write lock is usually
on top of a lock dependency chain which can include the journal lock, the
flush lock or the commit lock. So it's dangerous to release and trying to
reacquire the write lock while we still hold other locks.

This is fine with the bkl:

      T1                       T2

lock_kernel()
    mutex_lock(A)
    unlock_kernel()
    // do something
                            lock_kernel()
                                mutex_lock(A) -> already locked by T1
                                schedule() (and then unlock_kernel())
    lock_kernel()
    mutex_unlock(A)
    ....

This is not fine with a mutex:

      T1                       T2

mutex_lock(write)
    mutex_lock(A)
    mutex_unlock(write)
    // do something
                           mutex_lock(write)
                              mutex_lock(A) -> already locked by T1
                              schedule()

    mutex_lock(write) -> already locked by T2
    deadlock

The solution in this patch is to provide a helper which releases the write
lock and sleep a bit if we can't lock a mutex that depend on it. It's another
simulation of the bkl behaviour.

The last axis is to locate the fs callbacks that are called with the bkl held,
according to Documentation/filesystem/Locking.

Those are:

- reiserfs_remount
- reiserfs_fill_super
- reiserfs_put_super

Reiserfs didn't need to explicitly lock because of the context of these callbacks.
But now we must take care of that with the new locking.

After this patch, reiserfs suffers from a slight performance regression (for now).
On UP, a high volume write with dd reports an average of 27 MB/s instead
of 30 MB/s without the patch applied.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Bron Gondwana <brong@fastmail.fm>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
LKML-Reference: <1239070789-13354-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-14 07:17:59 +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
Jens Axboe 8aa7e847d8 Fix congestion_wait() sync/async vs read/write confusion
Commit 1faa16d228 accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-07-10 20:31:53 +02:00
Alexey Dobriyan b43f3cbd21 headers: mnt_namespace.h redux
Fix various silly problems wrt mnt_namespace.h:

 - exit_mnt_ns() isn't used, remove it
 - done that, sched.h and nsproxy.h inclusions aren't needed
 - mount.h inclusion was need for vfsmount_lock, but no longer
 - remove mnt_namespace.h inclusion from files which don't use anything
   from mnt_namespace.h

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-08 09:31:56 -07:00
Al Viro 073aaa1b14 helpers for acl caching + switch to those
helpers: get_cached_acl(inode, type), set_cached_acl(inode, type, acl),
forget_cached_acl(inode, type).

ubifs/xattr.c needed includes reordered, the rest is a plain switchover.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24 08:17:07 -04:00
Al Viro 281eede032 switch reiserfs to inode->i_acl
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24 08:17:06 -04:00
Al Viro 7a77b15d92 switch reiserfs to usual conventions for caching ACLs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24 08:17:06 -04:00
Al Viro e68888bcb6 reiserfs: minimal fix for ACL caching
reiserfs uses NULL as "unknown" and ERR_PTR(-ENODATA) as "no ACL";
several codepaths store the former instead of the latter.

All those codepaths go through iset_acl() and all cases when it's
called with NULL acl are for the second variety, so the minimal
fix is to teach iset_acl() to deal with that.

Proper fix is to switch to more usual conventions and avoid back
and forth between internally used ERR_PTR(-ENODATA) and NULL
expected by the rest of the kernel.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24 08:17:05 -04:00
Christoph Hellwig b5450d9c84 reiserfs: remove stray unlock_super in reiserfs_resize
Reiserfs doesn't use lock_super anywhere internally, and ->remount_fs
which calls reiserfs_resize does have it currently but also expects it
to be held on return, so there's no business for the unlock_super here.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked by Edward Shishkin <edward.shishkin@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24 08:15:24 -04:00
Jeff Mahoney 1d965fe0eb reiserfs: fix warnings with gcc 4.4
Several code paths in reiserfs have a construct like:

 if (is_direntry_le_ih(ih = B_N_PITEM_HEAD(src, item_num))) ...

which, in addition to being ugly, end up causing compiler warnings with
gcc 4.4.0.  Previous compilers didn't issue a warning.

fs/reiserfs/do_balan.c:1273: warning: operation on `aux_ih' may be undefined
fs/reiserfs/lbalance.c:393: warning: operation on `ih' may be undefined
fs/reiserfs/lbalance.c:421: warning: operation on `ih' may be undefined
fs/reiserfs/lbalance.c:777: warning: operation on `ih' may be undefined

I believe this is due to the ih being passed to macros which evaluate the
argument more than once.  This is old code and we haven't seen any
problems with it, but this patch eliminates the warnings.

It converts the multiple evaluation macros to static inlines and does a
preassignment for the cases that were causing the warnings because that
code is just ugly.

Reported-by: Chris Mason <mason@oracle.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:46 -07:00
Alessio Igor Bogani 337eb00a2c Push BKL down into ->remount_fs()
[xfs, btrfs, capifs, shmem don't need BKL, exempt]

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:11 -04:00
Christoph Hellwig 6cfd014842 push BKL down into ->put_super
Move BKL into ->put_super from the only caller.  A couple of
filesystems had trivial enough ->put_super (only kfree and NULLing of
s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs,
hugetlbfs, omfs, qnx4, shmem, all others got the full treatment.  Most
of them probably don't need it, but I'd rather sort that out individually.
Preferably after all the other BKL pushdowns in that area.

[AV: original used to move lock_super() down as well; these changes are
removed since we don't do lock_super() at all in generic_shutdown_super()
now]
[AV: fuse, btrfs and xfs are known to need no damn BKL, exempt]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:07 -04:00
Christoph Hellwig 5af7926ff3 enforce ->sync_fs is only called for rw superblock
Make sure a superblock really is writeable by checking MS_RDONLY
under s_umount.  sync_filesystems needed some re-arragement for
that, but all but one sync_filesystem caller had the correct locking
already so that we could add that check there.  cachefiles grew
s_umount locking.

I've also added a WARN_ON to sync_filesystem to assert this for
future callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:06 -04:00
Christoph Hellwig 8c85e12512 remove ->write_super call in generic_shutdown_super
We just did a full fs writeout using sync_filesystem before, and if
that's not enough for the filesystem it can perform it's own writeout
in ->put_super, which many filesystems already do.

Move a call to foofs_write_super into every foofs_put_super for now to
guarantee identical behaviour until it's cleaned up by the individual
filesystem maintainers.

Exceptions:

 - affs already has identical copy & pasted code at the beginning of
   affs_put_super so no need to do it twice.
 - xfs does the right thing without it and I have changes pending for
   the xfs tree touching this are so I don't really need conflicts
   here..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:06 -04:00
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
Al Viro 2a32cebd6c Fix races around the access to ->s_options
Put generic_show_options read access to s_options under rcu_read_lock,
split save_mount_options() into "we are setting it the first time"
(uses in foo_fill_super()) and "we are relacing and freeing the old one",
synchronize_rcu() before kfree() in the latter.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:51:34 -04:00
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 b82bb72ba7 reiserfs: dont associate security.* with xattr files
The security.* xattrs are ignored for xattr files, so don't create them.

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
Linus Torvalds 8fe74cf053 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  Remove two unneeded exports and make two symbols static in fs/mpage.c
  Cleanup after commit 585d3bc06f
  Trim includes of fdtable.h
  Don't crap into descriptor table in binfmt_som
  Trim includes in binfmt_elf
  Don't mess with descriptor table in load_elf_binary()
  Get rid of indirect include of fs_struct.h
  New helper - current_umask()
  check_unsafe_exec() doesn't care about signal handlers sharing
  New locking/refcounting for fs_struct
  Take fs_struct handling to new file (fs/fs_struct.c)
  Get rid of bumping fs_struct refcount in pivot_root(2)
  Kill unsharing fs_struct in __set_personality()
2009-04-02 21:09:10 -07:00
Coly Li 651d062304 fs/reiserfs: return f_fsid for statfs(2)
Make reiserfs3 return f_fsid info for statfs(2).  By Andreas' suggestion,
this patch populates a persistent f_fsid between boots/mounts with help of
on-disk uuid record.

Randy Dunlap reported a compiling error from v2 patch like:
    fs/built-in.o: In function `reiserfs_statfs':
    super.c:(.text+0x7332b): undefined reference to `crc32_le'
    super.c:(.text+0x7333f): undefined reference to `crc32_le'
Also he provided helpful solution to fix this error. The modification of v3
patch is based on Randy's suggestion, add 'select CRC32' in fs/reiserfs/Kconfig.

Signed-off-by: Coly Li <coly.li@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:05:10 -07:00
Al Viro ce3b0f8d5c New helper - current_umask()
current->fs->umask is what most of fs_struct users are doing.
Put that into a helper function.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:26 -04:00
Linus Torvalds cf2f7d7c90 Merge branch 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc
* 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc:
  Revert "proc: revert /proc/uptime to ->read_proc hook"
  proc 2/2: remove struct proc_dir_entry::owner
  proc 1/2: do PDE usecounting even for ->read_proc, ->write_proc
  proc: fix sparse warnings in pagemap_read()
  proc: move fs/proc/inode-alloc.txt comment into a source file
2009-03-30 16:06:04 -07:00
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
Alexey Dobriyan 99b7623380 proc 2/2: remove struct proc_dir_entry::owner
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-03-31 01:14:44 +04:00
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 ee93961be1 reiserfs: rename [cn]_* variables
This patch renames n_, c_, etc variables to something more sane.  This
is the sixth in a series of patches to rip out some of the awful
variable naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:40 -07:00
Jeff Mahoney d68caa9530 reiserfs: rename p_._ variables
This patch is a simple s/p_._//g to the reiserfs code.  This is the
fifth in a series of patches to rip out some of the awful variable
naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:40 -07:00
Jeff Mahoney a063ae1792 reiserfs: rename p_s_tb to tb
This patch is a simple s/p_s_tb/tb/g to the reiserfs code.  This is the
fourth in a series of patches to rip out some of the awful variable
naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:40 -07:00
Jeff Mahoney 995c762ea4 reiserfs: rename p_s_inode to inode
This patch is a simple s/p_s_inode/inode/g to the reiserfs code.  This
is the third in a series of patches to rip out some of the awful
variable naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:39 -07:00
Jeff Mahoney ad31a4fc03 reiserfs: rename p_s_bh to bh
This patch is a simple s/p_s_bh/bh/g to the reiserfs code.  This is the
second in a series of patches to rip out some of the awful variable
naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:39 -07:00
Jeff Mahoney a9dd364358 reiserfs: rename p_s_sb to sb
This patch is a simple s/p_s_sb/sb/g to the reiserfs code.  This is the
first in a series of patches to rip out some of the awful variable
naming in reiserfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:39 -07:00
Jeff Mahoney 0222e6571c reiserfs: strip trailing whitespace
This patch strips trailing whitespace from the reiserfs code.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:39 -07:00
Jeff Mahoney 3cd6dbe6fe reiserfs: cleanup path functions
This patch cleans up some redundancies in the reiserfs tree path code.

decrement_bcount() is essentially the same function as brelse(), so we use
that instead.

decrement_counters_in_path() is exactly the same function as pathrelse(), so
we kill that and use pathrelse() instead.

There's also a bit of cleanup that makes the code a bit more readable.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:39 -07:00
Jeff Mahoney fba4ebb5f0 reiserfs: factor out buffer_info initialization
This is the first in a series of patches to make balance_leaf() not
quite so insane.

This patch factors out the open coded initializations of buffer_info
structures and defines a few initializers for the 4 cases they're used.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:39 -07:00
Jeff Mahoney 57fe60df62 reiserfs: add atomic addition of selinux attributes during inode creation
Some time ago, some changes were made to make security inode attributes
be atomically written during inode creation.  ReiserFS fell behind in
this area, but with the reworking of the xattr code, it's now fairly
easy to add.

The following patch adds the ability for security attributes to be added
automatically during inode creation.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30 12:16:39 -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 1e5e59d431 reiserfs: introduce reiserfs_error()
Although reiserfs can currently handle severe errors such as journal failure,
it cannot handle less severe errors like metadata i/o failure. The following
patch adds a reiserfs_error() function akin to the one in ext3.

Subsequent patches will use this new error handler to handle errors more
gracefully in general.

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 32e8b10629 reiserfs: rearrange journal abort
This patch kills off reiserfs_journal_abort as it is never called, and
combines __reiserfs_journal_abort_{soft,hard} into one function called
reiserfs_abort_journal, which performs the same work. It is silent
as opposed to the old version, since the message was always issued
after a regular 'abort' message.

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 c3a9c2109f reiserfs: rework reiserfs_panic
ReiserFS panics 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 78b6513d28 reiserfs: add locking around error buffer
The formatting of the error buffer is race prone. It uses static buffers
for both formatting and output. While overwriting the error buffer
can product garbled output, overwriting the format buffer with incompatible
% directives can cause crashes.

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 cacbe3d7ad reiserfs: prepare_error_buf wrongly consumes va_arg
vsprintf will consume varargs on its own. Skipping them manually
results in garbage in the error buffer, or Oopses in the case of
pointers.

This patch removes the advancement and fixes a number of bugs where
crashes were observed as side effects of a regular error report.

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 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
Jeff Mahoney a5437152ee reiserfs: use more consistent printk formatting
The output format between a warning/error/panic/info/etc changes with
which one is used.

The following patch makes the messages more internally consistent, but also
more consistent with other Linux filesystems.

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
Jeff Mahoney eba0030559 reiserfs: use buffer_info for leaf_paste_entries
This patch makes leaf_paste_entries more consistent with respect to the
other leaf operations.  Using buffer_info instead of buffer_head
directly allows us to get a superblock pointer for use in error
handling.

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
Jeff Mahoney 600ed41675 reiserfs: audit transaction ids to always be unsigned ints
This patch fixes up the reiserfs code such that transaction ids are
always unsigned ints.  In places they can currently be signed ints or
unsigned longs.

The former just causes an annoying clm-2200 warning and may join a
transaction when it should wait.

The latter is just for correctness since the disk format uses a 32-bit
transaction id.  There aren't any runtime problems that result from it
not wrapping at the correct location since the value is truncated
correctly even on big endian systems.  The 0 value might make it to
disk, but the mount-time checks will bump it to 10 itself.

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
Jeff Mahoney 702d21c6f6 reiserfs: add support for mount count incrementing
The following patch adds the fields for tracking mount counts and last
fsck timestamps to the superblock.  It also increments the mount count
on every read-write mount.

Reiserfsprogs 3.6.21 added support for these fields.

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
Linus Torvalds 3ae5080f4c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits)
  fs: avoid I_NEW inodes
  Merge code for single and multiple-instance mounts
  Remove get_init_pts_sb()
  Move common mknod_ptmx() calls into caller
  Parse mount options just once and copy them to super block
  Unroll essentials of do_remount_sb() into devpts
  vfs: simple_set_mnt() should return void
  fs: move bdev code out of buffer.c
  constify dentry_operations: rest
  constify dentry_operations: configfs
  constify dentry_operations: sysfs
  constify dentry_operations: JFS
  constify dentry_operations: OCFS2
  constify dentry_operations: GFS2
  constify dentry_operations: FAT
  constify dentry_operations: FUSE
  constify dentry_operations: procfs
  constify dentry_operations: ecryptfs
  constify dentry_operations: CIFS
  constify dentry_operations: AFS
  ...
2009-03-27 16:23:12 -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
Jan Kara 77db4f25bc reiserfs: Use lowercase names of quota functions
Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara <jack@suse.cz>
CC: reiserfs-devel@vger.kernel.org
2009-03-26 02:18:36 +01:00
Jan Kara 643d00ccc3 reiserfs: Remove unnecessary quota functions
reiserfs_dquot_initialize() and reiserfs_dquot_drop() is no longer
needed because of modified quota locking.

Signed-off-by: Jan Kara <jack@suse.cz>
2009-03-26 02:18:34 +01:00
Alexey Dobriyan b16ecfe2f9 fs/Kconfig: move reiserfs out
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-22 13:15:53 +03:00
Takashi Sato c4be0c1dc4 filesystem freeze: add error handling of write_super_lockfs/unlockfs
Currently, ext3 in mainline Linux doesn't have the freeze feature which
suspends write requests.  So, we cannot take a backup which keeps the
filesystem's consistency with the storage device's features (snapshot and
replication) while it is mounted.

In many case, a commercial filesystem (e.g.  VxFS) has the freeze feature
and it would be used to get the consistent backup.

If Linux's standard filesystem ext3 has the freeze feature, we can do it
without a commercial filesystem.

So I have implemented the ioctls of the freeze feature.
I think we can take the consistent backup with the following steps.
1. Freeze the filesystem with the freeze ioctl.
2. Separate the replication volume or create the snapshot
   with the storage device's feature.
3. Unfreeze the filesystem with the unfreeze ioctl.
4. Take the backup from the separated replication volume
   or the snapshot.

This patch:

VFS:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that they can return an error.
Rename write_super_lockfs and unlockfs of the super block operation
freeze_fs and unfreeze_fs to avoid a confusion.

ext3, ext4, xfs, gfs2, jfs:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that write_super_lockfs returns an error if needed,
and unlockfs always returns 0.

reiserfs:
Changed the type of write_super_lockfs and unlockfs from "void"
to "int" so that they always return 0 (success) to keep a current behavior.

Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Masayuki Hamaguchi <m-hamaguchi@ys.jp.nec.com>
Cc: <xfs-masters@oss.sgi.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-09 16:54:42 -08:00
Linus Torvalds 10cc04f5a0 Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2: (138 commits)
  ocfs2: Access the right buffer_head in ocfs2_merge_rec_left.
  ocfs2: use min_t in ocfs2_quota_read()
  ocfs2: remove unneeded lvb casts
  ocfs2: Add xattr support checking in init_security
  ocfs2: alloc xattr bucket in ocfs2_xattr_set_handle
  ocfs2: calculate and reserve credits for xattr value in mknod
  ocfs2/xattr: fix credits calculation during index create
  ocfs2/xattr: Always updating ctime during xattr set.
  ocfs2/xattr: Remove extend_trans call and add its credits from the beginning
  ocfs2/dlm: Fix race during lockres mastery
  ocfs2/dlm: Fix race in adding/removing lockres' to/from the tracking list
  ocfs2/dlm: Hold off sending lockres drop ref message while lockres is migrating
  ocfs2/dlm: Clean up errors in dlm_proxy_ast_handler()
  ocfs2/dlm: Fix a race between migrate request and exit domain
  ocfs2: One more hamming code optimization.
  ocfs2: Another hamming code optimization.
  ocfs2: Don't hand-code xor in ocfs2_hamming_encode().
  ocfs2: Enable metadata checksums.
  ocfs2: Validate superblock with checksum and ecc.
  ocfs2: Checksum and ECC for directory blocks.
  ...
2009-01-05 18:32:43 -08:00
Linus Torvalds 520c853466 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  inotify: fix type errors in interfaces
  fix breakage in reiserfs_new_inode()
  fix the treatment of jfs special inodes
  vfs: remove duplicate code in get_fs_type()
  add a vfs_fsync helper
  sys_execve and sys_uselib do not call into fsnotify
  zero i_uid/i_gid on inode allocation
  inode->i_op is never NULL
  ntfs: don't NULL i_op
  isofs check for NULL ->i_op in root directory is dead code
  affs: do not zero ->i_op
  kill suid bit only for regular files
  vfs: lseek(fd, 0, SEEK_CUR) race condition
2009-01-05 18:32:06 -08:00
Al Viro 2f1169e2dc fix breakage in reiserfs_new_inode()
now that we use ih.key earlier, we need to do all its setup early enough

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:29 -05:00
Jan Kara 4103003b3a reiserfs: Add default allocation routines for quota structures
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05 08:40:25 -08:00