We may access and update transaction->aborted on the different CPUs without
lock, so we need ACCESS_ONCE() wrapper to prevent the compiler from creating
unsolicited accesses and make sure we can get the right value.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The auto defrag allocation is in the fast path of the IO, so use slabs
to improve the speed of the allocation.
And besides that, it can do check for leaked objects when the module is removed.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This commit contains all the essential changes to the core code
of Btrfs for support of the device replace procedure.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
The device replace procedure makes use of the scrub code. The scrub
code is the most efficient code to read the allocated data of a disk,
i.e. it reads sequentially in order to avoid disk head movements, it
skips unallocated blocks, it uses read ahead mechanisms, and it
contains all the code to detect and repair defects.
This commit adds code to scrub to allow the scrub code to copy read
data to another disk.
One goal is to be able to perform as fast as possible. Therefore the
write requests are collected until huge bios are built, and the
write process is decoupled from the read process with some kind of
flow control, of course, in order to limit the allocated memory.
The best performance on spinning disks could by reached when the
head movements are avoided as much as possible. Therefore a single
worker is used to interface the read process with the write process.
The regular scrub operation works as fast as before, it is not
negatively influenced and actually it is more or less unchanged.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This patch adds some code to disallow operations on the device that
is used as the target for the device replace operation.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Remove the attempt to cancel a running scrub or device replace
operation in btrfs_handle_error() because it adds the risk of
a deadlock. The only penalty of not canceling the operation is
that some I/O remains active until the procedure completes.
This is basically the same thing that happens to other tasks
that are running in user mode context, they are not affected
or stopped in btrfs_handle_error(), these tasks just need to
handle write errors correctly.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
A small number of functions that are used in a device replace
procedure when the operation is resumed at mount time are unable
to pass the same root pointer that would be used in the regular
(ioctl) context. And since the root pointer is not required, only
the fs_info is, the root pointer argument is replaced with the
fs_info pointer argument.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
The current behavior is to allow mounting or remounting a filesystem
writeable in degraded mode if at least one writeable device is
present.
The next failed write access to a missing device which is above
the tolerance of the configured level of redundancy results in an
read-only enforcement. Even without this, the next time
barrier_all_devices() is called and more devices are missing than
tolerable, the switch to read-only mode takes place.
In order to behave predictably and to provide proper feedback to
the user at mount time, this patch compares the number of missing
devices with the number of devices that are tolerated to be missing
according to the configured RAID level. If more devices are missing
than tolerated, e.g. if two devices are missing in case of RAID1,
only a read-only mount and remount is allowed.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
If a filesystem is mounted with compression and then remounted by adding nodatacow,
the compression is disabled but the compress flag is still visible.
Also, if a filesystem is mounted with nodatacow and then remounted with compression,
nodatacow flag is still present but it's not active.
This patch:
- removes compress flags and notifies that the compression has been disabled if the
filesystem is mounted with nodatacow
- removes nodatacow and nodatasum flags if mounted with compress.
Signed-off-by: Andrei Popa <andrei.popa@i-neo.ro>
With the following debug patch:
static int btrfs_freeze(struct super_block *sb)
{
+ struct btrfs_fs_info *fs_info = btrfs_sb(sb);
+ struct btrfs_transaction *trans;
+
+ spin_lock(&fs_info->trans_lock);
+ trans = fs_info->running_transaction;
+ if (trans) {
+ printk("Transid %llu, use_count %d, num_writer %d\n",
+ trans->transid, atomic_read(&trans->use_count),
+ atomic_read(&trans->num_writers));
+ }
+ spin_unlock(&fs_info->trans_lock);
return 0;
}
I found there was a orphan transaction after the freeze operation was done.
It is because the transaction may not be committed when the transaction handle
end even though it is the last handle of the current transaction. This design
avoid committing the transaction frequently, but also introduce the above
problem.
So I add btrfs_attach_transaction() which can catch the current transaction
and commit it. If there is no transaction, it will return ENOENT, and do not
anything.
This function also can be used to instead of btrfs_join_transaction_freeze()
because it don't increase the writer counter and don't start a new transaction,
so it also can fix the deadlock between sync and freeze.
Besides that, it is used to instead of btrfs_join_transaction() in
transaction_kthread(), because if there is no transaction, the transaction
kthread needn't anything.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
We do not need to do anything special to freeze or unfreeze, it's all taken
care of by the generic work, and what we currently have is wrong anyway
since we shouldn't be returnning to userspace with mutexes held anyway.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
I screwed this up, there is a race between checking if there is a running
transaction and actually starting a transaction in sync where we could race
with a freezer and get ourselves into trouble. To fix this we need to make
a new join type to only do the try lock on the freeze stuff. If it fails
we'll return EPERM and just return from sync. This fixes a hang Liu Bo
reported when running xfstest 68 in a loop. Thanks,
Reported-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
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: Miao 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: Miao Xie <miaox@cn.fujitsu.com>
Pull btrfs fixes from Chris Mason:
"I've split out the big send/receive update from my last pull request
and now have just the fixes in my for-linus branch. The send/recv
branch will wander over to linux-next shortly though.
The largest patches in this pull are Josef's patches to fix DIO
locking problems and his patch to fix a crash during balance. They
are both well tested.
The rest are smaller fixes that we've had queued. The last rc came
out while I was hacking new and exciting ways to recover from a
misplaced rm -rf on my dev box, so these missed rc3."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (25 commits)
Btrfs: fix that repair code is spuriously executed for transid failures
Btrfs: fix ordered extent leak when failing to start a transaction
Btrfs: fix a dio write regression
Btrfs: fix deadlock with freeze and sync V2
Btrfs: revert checksum error statistic which can cause a BUG()
Btrfs: remove superblock writing after fatal error
Btrfs: allow delayed refs to be merged
Btrfs: fix enospc problems when deleting a subvol
Btrfs: fix wrong mtime and ctime when creating snapshots
Btrfs: fix race in run_clustered_refs
Btrfs: don't run __tree_mod_log_free_eb on leaves
Btrfs: increase the size of the free space cache
Btrfs: barrier before waitqueue_active
Btrfs: fix deadlock in wait_for_more_refs
btrfs: fix second lock in btrfs_delete_delayed_items()
Btrfs: don't allocate a seperate csums array for direct reads
Btrfs: do not strdup non existent strings
Btrfs: do not use missing devices when showing devname
Btrfs: fix that error value is changed by mistake
Btrfs: lock extents as we map them in DIO
...
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: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris 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: Josef 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: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al 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: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull large btrfs update from Chris Mason:
"This pull request is very large, and the two main features in here
have been under testing/devel for quite a while.
We have subvolume quotas from the strato developers. This enables
full tracking of how many blocks are allocated to each subvolume (and
all snapshots) and you can set limits on a per-subvolume basis. You
can also create quota groups and toss multiple subvolumes into a big
group. It's everything you need to be a web hosting company and give
each user their own subvolume.
The userland side of the quotas is being refreshed, they'll send out
details on where to grab it soon.
Next is the kernel side of btrfs send/receive from Alexander Block.
This leverages the same infrastructure as the quota code to figure out
relationships between blocks and their owners. It can then compute
the difference between two snapshots and sends the diffs in a neutral
format into userland.
The basic model:
create a snapshot
send that snapshot as the initial backup
make changes
create a second snapshot
send the incremental as a backup
delete the first snapshot
(use the second snapshot for the next incremental)
The receive portion is all in userland, and in the 'next' branch of my
btrfs-progs repo.
There's still some work to do in terms of optimizing the send side
from kernel to userland. The really important part is figuring out
how two snapshots are different, and this is where we are
concentrating right now. The initial send of a dataset is a little
slower than tar, but the incremental sends are dramatically faster
than what rsync can do.
On top of all of that, we have a nice queue of fixes, cleanups and
optimizations."
Fix up trivial modify/del conflict in fs/btrfs/ioctl.c
Also fix up semantic conflict in fs/btrfs/send.c: the interface to
dentry_open() changed in commit 765927b2d5 ("switch dentry_open() to
struct path, make it grab references itself"), and since it now grabs
whatever references it needs, we should no longer do the mntget() on the
mnt (and we need to dput() the dentry reference we took).
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (65 commits)
Btrfs: uninit variable fixes in send/receive
Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive
Btrfs: add btrfs_compare_trees function
Btrfs: introduce subvol uuids and times
Btrfs: make iref_to_path non static
Btrfs: add a barrier before a waitqueue_active check
Btrfs: call the ordered free operation without any locks held
Btrfs: Check INCOMPAT flags on remount and add helper function
Btrfs: add helper for tree enumeration
btrfs: allow cross-subvolume file clone
Btrfs: improve multi-thread buffer read
Btrfs: make btrfs's allocation smoothly with preallocation
Btrfs: lock the transition from dirty to writeback for an eb
Btrfs: fix potential race in extent buffer freeing
Btrfs: don't return true in releasepage unless we actually freed the eb
Btrfs: suppress printk() if all device I/O stats are zero
Btrfs: remove unwanted printk() for btrfs device I/O stats
Btrfs: rewrite BTRFS_SETGET_FUNCS
Btrfs: zero unused bytes in inode item
Btrfs: kill free_space pointer from inode structure
...
Conflicts:
fs/btrfs/ioctl.c
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: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Chris 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: Josef 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: David Sterba <dsterba@suse.cz>
Signed-off-by: Arnd 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: Josef 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: David Howells <dhowells@redhat.com>
Signed-off-by: Al 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: Ilya 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: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef 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: Josef Bacik <josef@redhat.com>
Signed-off-by: Jim 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: Jim 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: Josef Bacik <josef@redhat.com>
Signed-off-by: Sergei 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: Josef Bacik <josef@redhat.com>
Pull btrfs fixes from Chris Mason:
"This has our collection of bug fixes. I missed the last rc because I
thought our patches were making NFS crash during my xfs test runs.
Turns out it was an NFS client bug fixed by someone else while I tried
to bisect it.
All of these fixes are small, but some are fairly high impact. The
biggest are fixes for our mount -o remount handling, a deadlock due to
GFP_KERNEL allocations in readdir, and a RAID10 error handling bug.
This was tested against both 3.3 and Linus' master as of this morning."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (26 commits)
Btrfs: reduce lock contention during extent insertion
Btrfs: avoid deadlocks from GFP_KERNEL allocations during btrfs_real_readdir
Btrfs: Fix space checking during fs resize
Btrfs: fix block_rsv and space_info lock ordering
Btrfs: Prevent root_list corruption
Btrfs: fix repair code for RAID10
Btrfs: do not start delalloc inodes during sync
Btrfs: fix that check_int_data mount option was ignored
Btrfs: don't count CRC or header errors twice while scrubbing
Btrfs: fix btrfs_ioctl_dev_info() crash on missing device
btrfs: don't return EINTR
Btrfs: double unlock bug in error handling
Btrfs: always store the mirror we read the eb from
fs/btrfs/volumes.c: add missing free_fs_devices
btrfs: fix early abort in 'remount'
Btrfs: fix max chunk size check in chunk allocator
Btrfs: add missing read locks in backref.c
Btrfs: don't call free_extent_buffer twice in iterate_irefs
Btrfs: Make free_ipath() deal gracefully with NULL pointers
Btrfs: avoid possible use-after-free in clear_extent_bit()
...
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: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris 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: Sergei Trofimovich <slyfox@gentoo.org>
Pull btrfs fixes and features from Chris Mason:
"We've merged in the error handling patches from SuSE. These are
already shipping in the sles kernel, and they give btrfs the ability
to abort transactions and go readonly on errors. It involves a lot of
churn as they clarify BUG_ONs, and remove the ones we now properly
deal with.
Josef reworked the way our metadata interacts with the page cache.
page->private now points to the btrfs extent_buffer object, which
makes everything faster. He changed it so we write an whole extent
buffer at a time instead of allowing individual pages to go down,,
which will be important for the raid5/6 code (for the 3.5 merge
window ;)
Josef also made us more aggressive about dropping pages for metadata
blocks that were freed due to COW. Overall, our metadata caching is
much faster now.
We've integrated my patch for metadata bigger than the page size.
This allows metadata blocks up to 64KB in size. In practice 16K and
32K seem to work best. For workloads with lots of metadata, this cuts
down the size of the extent allocation tree dramatically and fragments
much less.
Scrub was updated to support the larger block sizes, which ended up
being a fairly large change (thanks Stefan Behrens).
We also have an assortment of fixes and updates, especially to the
balancing code (Ilya Dryomov), the back ref walker (Jan Schmidt) and
the defragging code (Liu Bo)."
Fixed up trivial conflicts in fs/btrfs/scrub.c that were just due to
removal of the second argument to k[un]map_atomic() in commit
7ac687d9e0.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (75 commits)
Btrfs: update the checks for mixed block groups with big metadata blocks
Btrfs: update to the right index of defragment
Btrfs: do not bother to defrag an extent if it is a big real extent
Btrfs: add a check to decide if we should defrag the range
Btrfs: fix recursive defragment with autodefrag option
Btrfs: fix the mismatch of page->mapping
Btrfs: fix race between direct io and autodefrag
Btrfs: fix deadlock during allocating chunks
Btrfs: show useful info in space reservation tracepoint
Btrfs: don't use crc items bigger than 4KB
Btrfs: flush out and clean up any block device pages during mount
btrfs: disallow unequal data/metadata blocksize for mixed block groups
Btrfs: enhance superblock sanity checks
Btrfs: change scrub to support big blocks
Btrfs: minor cleanup in scrub
Btrfs: introduce common define for max number of mirrors
Btrfs: fix infinite loop in btrfs_shrink_device()
Btrfs: fix memory leak in resolver code
Btrfs: allow dup for data chunks in mixed mode
Btrfs: validate target profiles only if we are going to use them
...
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: Jan 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: Jeff 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: Jeff 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: Jeff Mahoney <jeffm@suse.com>
* 'btrfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
btrfs: take allocation of ->tree_root into open_ctree()
btrfs: let ->s_fs_info point to fs_info, not root...
btrfs: consolidate failure exits in btrfs_mount() a bit
btrfs: make free_fs_info() call ->kill_sb() unconditional
btrfs: merge free_fs_info() calls on fill_super failures
btrfs: kill pointless reassignment of ->s_fs_info in btrfs_fill_super()
btrfs: make open_ctree() return int
btrfs: sanitizing ->fs_info, part 5
btrfs: sanitizing ->fs_info, part 4
btrfs: sanitizing ->fs_info, part 3
btrfs: sanitizing ->fs_info, part 2
btrfs: sanitizing ->fs_info, part 1
btrfs: fix a deadlock in btrfs_scan_one_device()
btrfs: fix mount/umount race
btrfs: get ->kill_sb() of its own
btrfs: preparation to fixing mount/umount race
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (62 commits)
Btrfs: use larger system chunks
Btrfs: add a delalloc mutex to inodes for delalloc reservations
Btrfs: space leak tracepoints
Btrfs: protect orphan block rsv with spin_lock
Btrfs: add allocator tracepoints
Btrfs: don't call btrfs_throttle in file write
Btrfs: release space on error in page_mkwrite
Btrfs: fix btrfsck error 400 when truncating a compressed
Btrfs: do not use btrfs_end_transaction_throttle everywhere
Btrfs: add balance progress reporting
Btrfs: allow for resuming restriper after it was paused
Btrfs: allow for canceling restriper
Btrfs: allow for pausing restriper
Btrfs: add skip_balance mount option
Btrfs: recover balance on mount
Btrfs: save balance parameters to disk
Btrfs: soft profile changing mode (aka soft convert)
Btrfs: implement online profile changing
Btrfs: do not reduce profile in do_chunk_alloc()
Btrfs: virtual address space subset filter
...
Fix up trivial conflict in fs/btrfs/ioctl.c due to the use of the new
mnt_drop_write_file() helper.
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: Ilya Dryomov <idryomov@gmail.com>