Though we dump the stack information when aborting a unused transaction
handle, we don't know the correct place where we decide to abort the
transaction handle if one function has several place where the transaction
abort function is invoked and jumps to the same place after this call.
And beside that we also don't know the reason why we jump to abort
the current handle. So I modify the transaction abort function and make
it output the function name, line and error information.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>

The ordered extent allocation is in the fast path of the IO, so use a slab
to improve the speed of the allocation.

 "Size of the struct is 280, so this will fall into the size-512 bucket,
  giving 8 objects per page, while own slab will pack 14 objects into a page.

  Another benefit I see is to check for leaked objects when the module is
  removed (and the cache destroy takes place)."
						-- David Sterba
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>

We can deadlock with freeze right now because we unconditionally start a
transaction in our ->sync_fs() call.  To fix this just check and see if we
have a running transaction to commit.  This saves us from the deadlock
because at this point we'll have the umount sem for the sb so we're safe
from freezes coming in after we've done our check.  With this patch the
freeze xfstests no longer deadlocks.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

If you do the following

mkfs.btrfs /dev/sdb /dev/sdc
rmmod btrfs
dd if=/dev/zero of=/dev/sdb bs=1M count=1
mount -o degraded /dev/sdc /mnt/btrfs-test

the box will panic trying to deref the name for the missing dev since it is
the lower numbered devid.  So fix show_devname to not use missing devices.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The '->write_super' superblock method is gone, and this patch removes all the
references to 'write_super' from btrfs.

Cc: Chris Mason <chris.mason@fusionio.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Use the generic printk_get_level() to search a message for a kern_level.

Add __printf to verify format and arguments.  Fix a few messages that
had mismatches in format and arguments.  Add #ifdef CONFIG_PRINTK blocks
to shrink the object size a bit when not using printk.

[akpm@linux-foundation.org: whitespace tweak]
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In support of the recently added capability to remount with lzo
compression, provide a helper function to check the compression
INCOMPAT flags when remounting with lzo compression, and set
the flags if necessary.

Also, implement the new helper function when defragmenting with
explicit lzo compression and when setting the default subvolume.
Signed-off-by: NMitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This will be used in conjunction with btrfs device ready <dev>.  This is
needed for initrd's to have a nice and lightweight way to tell if all of the
devices needed for a file system are in the cache currently.  This keeps
them from having to do mount+sleep loops waiting for devices to show up.
Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Btrfs allows to turn on compression on a mounted and used filesystem
by issuing mount -o remount,compress=lzo.
This patch allows to turn compression off again
while the filesystem is mounted. As suggested by David Sterba
if the compress-force option was set, it is implicitly cleared
if compression is turned off.
Tested-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NArnd Hannemann <arnd@arndnet.de>

We do all of our inode updating when we change it, and now that we do
->update_time we don't need ->dirty_inode for atime updates anymore, so just
remove it.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

Pass mount flags to sget() so that it can use them in initialising a new
superblock before the set function is called.  They could also be passed to the
compare function.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This introduces btrfs_resume_balance_async(), which, given that
restriper state was recovered earlier by btrfs_recover_balance(),
resumes balance in btrfs-balance kthread.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Because btrfs can remove the device that was mounted we need to have a
->show_devname so that in this case we can print out some other device in
the file system to /proc/mount.  So if there are multiple devices in a btrfs
file system we will just print the device with the lowest devid that we can
find.  This will make everything consistent and deal with device removal
properly.  The drawback is if you mount with a device that is higher than
the lowest devicd it won't show up as the mounted device in /proc/mounts,
but this is a small price to pay. This was inspired by Miao Xie's patch.
Thanks,
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <josef@redhat.com>

There is an off-by-one error: allocating room for a maximal result
string but without room for a trailing NUL.  That, can lead to
returning a transformed string that is not NUL-terminated, and
then to a caller reading beyond end of the malloc'd buffer.

Rewrite to s/kzalloc/kmalloc/, remove unwarranted use of strncpy
(the result is guaranteed to fit), remove dead strlen at end, and
change a few variable names and comments.
Reviewed-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NJim Meyering <meyering@redhat.com>

The buffer read-overrun would be triggered by a printk format
starting with <N>, where N is a single digit.  NUL-terminate
after strncpy.  Use memcpy, not strncpy, since we know the
string we're copying fits in the destination buffer and
contains no NUL byte.
Signed-off-by: NJim Meyering <meyering@redhat.com>

Changing 'mount -oremount,thread_pool=2 /' didn't make any effect:

maximum amount of worker threads is specified in 2 places:
- in 'strict btrfs_fs_info::thread_pool_size'
- in each worker struct: 'struct btrfs_workers::max_workers'

'mount -oremount' updated only 'btrfs_fs_info::thread_pool_size'.

Fix it by pushing new maximum value to all created worker structures
as well.

Cc: Josef Bacik <josef@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Reviewed-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>

We've been keeping around the inode sequence number in hopes that somebody
would use it, but nobody uses it and people actually use i_version which
serves the same purpose, so use i_version where we used the incore inode's
sequence number and that way the sequence is updated properly across the
board, and not just in file write.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

btrfs_start_delalloc_inodes will just walk the list of delalloc inodes and
start writing them out, but it doesn't splice the list or anything so as
long as somebody is doing work on the box you could end up in this section
_forever_.  So just remove it, it's not needed anyway since sync will start
writeback on all inodes anyway, all we need to do is wait for ordered
extents and then we can commit the transaction.  In my horrible torture test
sync goes from taking 4 minutes to about 1.5 minutes.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Josef Bacik <josef@redhat.com>
Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>

btrfs_init_lockdep only makes our lockdep class names look prettier, thus
it did never hurt we forgot to actually call it. This turns our lockdep
identifier strings from lockdep auto-set #[id] into really pretty
"btrfs-fs-01" or "btrfs-csum-03".
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

 btrfs currently handles most errors with BUG_ON. This patch is a work-in-
 progress but aims to handle most errors other than internal logic
 errors and ENOMEM more gracefully.

 This iteration prevents most crashes but can run into lockups with
 the page lock on occasion when the timing "works out."
Signed-off-by: NJeff Mahoney <jeffm@suse.com>

Signed-off-by: NJeff Mahoney <jeffm@suse.com>

 btrfs currently handles most errors with BUG_ON. This patch is a work-in-
 progress but aims to handle most errors other than internal logic
 errors and ENOMEM more gracefully.

 This iteration prevents most crashes but can run into lockups with
 the page lock on occasion when the timing "works out."
Signed-off-by: NJeff Mahoney <jeffm@suse.com>

Signed-off-by: NJeff Mahoney <jeffm@suse.com>

As part of the effort to eliminate BUG_ON as an error handling
technique, we need to determine which errors are actual logic errors,
which are on-disk corruption, and which are normal runtime errors
e.g. -ENOMEM.

Annotating these error cases is helpful to understand and report them.

This patch adds a btrfs_panic() routine that will either panic
or BUG depending on the new -ofatal_errors={panic,bug} mount option.
Since there are still so many BUG_ONs, it defaults to BUG for now but I
expect that to change once the error handling effort has made
significant progress.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>

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

Since restriper kthread starts involuntarily on mount and can suck cpu
and memory bandwidth add a mount option to forcefully skip it.  The
restriper in that case hangs around in paused state and can be resumed
from userspace when it's convenient.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

now that we don't need it for sget() anymore...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

the latter can be obtained from the former (by looking as ->tree_root)
just as cheaply as we currently are doing the other way round.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

... and don't bother with it after btrfs_fill_super() failure -
->kill_sb() (unlike ->put_super()) will be called even if we
have not got non-NULL ->s_root.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... all the way up into btrfs_mount().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We do not (fortunately) modify ->s_fs_info of superblock on the fly in
btrfs_fill_super(); apparent assignment is a no-op.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

It returns either ERR_PTR(-ve) or sb->s_fs_info.  The latter can
be found by caller just as well, TYVM, no need to return it.  Just
return -ve or 0...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

A new helper: btrfs_alloc_root(fs_info); allocates btrfs_root
and sets ->fs_info.  All places allocating the suckers converted
to it.  At that point we *never* reassign ->fs_info of btrfs_root;
it's set before anyone sees the address of newly allocated
struct btrfs_root and never assigned anywhere else.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Do *NOT* skip doomed superblocks in btrfs_test_super(); we want
sget() to wait for their shutdown to complete.  Since we don't
mutilate ->s_fs_info in ->put_super() anymore (or free what it
used to point to until the superblock is past being findable
by sget()), we can just DTRT there and report a match.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and move free_fs_info() to that, out of ->put_super().  Do NOT
set ->s_fs_info to NULL in the latter; we need it for sget() to
be able to see and wait for fs in the middle of umount if we get a
mount/umount race.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We need fs_info and root to live until the moment when the victim
superblock leaves the list, so we need to postpone free_fs_info()
until after ->put_super().  The call is buried in close_ctree(),
though, so we need to lift it into the callers (including
btrfs_put_super()) first.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

it's not needed anymore; we used to, back when we had to do
mount_subtree() by hand, complete with put_mnt_ns() in it.
No more...  Apparmor didn't need it since the __d_path() fix.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>