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2767 commits

Author SHA1 Message Date
Josef Bacik
0fa83cdb1d Btrfs: only warn if we hit an error when doing the tree logging
I hit this a couple times while working on my fsync patch (all my bugs, not
normal operation), but with my new stuff we could have new errors from cases
I have not encountered, so instead of BUG()'ing we should be WARN()'ing so
that we are notified there is a problem but the user doesn't lose their
data.  We can easily commit the transaction in the case that the tree
logging fails and still be fine, so let's try and be as nice to the user as
possible.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-01 15:19:03 -04:00
Josef Bacik
5dc562c541 Btrfs: turbo charge fsync
At least for the vm workload.  Currently on fsync we will

1) Truncate all items in the log tree for the given inode if they exist

and

2) Copy all items for a given inode into the log

The problem with this is that for things like VMs you can have lots of
extents from the fragmented writing behavior, and worst yet you may have
only modified a few extents, not the entire thing.  This patch fixes this
problem by tracking which transid modified our extent, and then when we do
the tree logging we find all of the extents we've modified in our current
transaction, sort them and commit them.  We also only truncate up to the
xattrs of the inode and copy that stuff in normally, and then just drop any
extents in the range we have that exist in the log already.  Here are some
numbers of a 50 meg fio job that does random writes and fsync()s after every
write

		Original	Patched
SATA drive	82KB/s		140KB/s
Fusion drive	431KB/s		2532KB/s

So around 2-6 times faster depending on your hardware.  There are a few
corner cases, for example if you truncate at all we have to do it the old
way since there is no way to be sure what is in the log is ok.  This
probably could be done smarter, but if you write-fsync-truncate-write-fsync
you deserve what you get.  All this work is in RAM of course so if your
inode gets evicted from cache and you read it in and fsync it we'll do it
the slow way if we are still in the same transaction that we last modified
the inode in.

The biggest cool part of this is that it requires no changes to the recovery
code, so if you fsync with this patch and crash and load an old kernel, it
will run the recovery and be a-ok.  I have tested this pretty thoroughly
with an fsync tester and everything comes back fine, as well as xfstests.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-01 15:19:03 -04:00
Josef Bacik
224ecce517 Btrfs: fix possible corruption when fsyncing written prealloced extents
While working on my fsync patch my fsync tester kept hitting mismatching
md5sums when I would randomly write to a prealloc'ed region, syncfs() and
then write to the prealloced region some more and then fsync() and then
immediately reboot.  This is because the tree logging code will skip writing
csums for file extents who's generation is less than the current running
transaction.  When we mark extents as written we haven't been updating their
generation so they were always being skipped.  This wouldn't happen if you
were to preallocate and then write in the same transaction, but if you for
example prealloced a VM you could definitely run into this problem.  This
patch makes my fsync tester happy again.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-01 15:19:02 -04:00
Josef Bacik
54338b5cc4 Btrfs: do not allocate chunks as agressively
Swinging this pendulum back the other way.  We've been allocating chunks up
to 2% of the disk no matter how much we actually have allocated.  So instead
fix this calculation to only allocate chunks if we have more than 80% of the
space available allocated.  Please test this as it will likely cause all
sorts of ENOSPC problems to pop up suddenly.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-01 15:19:02 -04:00
Josef Bacik
7c735313bd Btrfs: update last trans if we don't update the inode
There is a completely impossible situation to hit where you can preallocate
a file, fsync it, write into the preallocated region, have the transaction
commit twice and then fsync and then immediately lose power and lose all of
the contents of the write.  This patch fixes this just so I feel better
about the situation and because it is lightweight, we just update the
last_trans when we finish an ordered IO and we don't update the inode
itself.  This way we are completely safe and I feel better.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-10-01 15:19:02 -04:00
Jan Schmidt
995e01b7af Btrfs: fix gcc warnings for 32bit compiles
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-10-01 15:19:01 -04:00
Chris Mason
74dd17fbe3 Btrfs: fix btrfs send for inline items and compression
The btrfs send code was assuming the offset of the file item into the
extent translated to bytes on disk.  If we're compressed, this isn't
true, and so it was off into extents owned by other files.

It was also improperly handling inline extents.  This solves a crash
where we may have gone past the end of the file extent item by not
testing early enough for an inline extent.  It also solves problems
where we have a whole between the end of the inline item and the start
of the full extent.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-10-01 15:19:00 -04:00
Alexander Block
6d85ed05e1 Btrfs: don't treat top/root directory inode as deleted/reused
We can't do the deleted/reused logic for top/root inodes as it would
create a stream that tries to delete and recreate the root dir.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:19:00 -04:00
Alexander Block
2981e225f7 Btrfs: ignore non-FS inodes for send/receive
We have to ignore inode/space cache objects in send/receive.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:59 -04:00
Alexander Block
2f28f4787c Btrfs: pass root instead of parent_root to iterate_inode_ref
We need to pass the root that we determined earlier to iterate_inode_ref.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:58 -04:00
Alexander Block
d8347fa444 Btrfs: use <= instead of < in is_extent_unchanged
Used the wrong compare operator here.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:58 -04:00
Alexander Block
3954096d4b Btrfs: fix check for changed extent in is_extent_unchanged
The previous check was working fine, but this check should be
easier to read. Also, we could theoritically have some exotic
bugs with the previous checks.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:57 -04:00
Alexander Block
5dc67d0ba9 Btrfs: free nce and nce_head on error in name_cache_insert
Both were leaked in case of error.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:56 -04:00
Alexander Block
3e126f32f8 Btrfs: remove unused tmp_path from iterate_dir_item
A leftover from older code and unused now.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:55 -04:00
Alexander Block
e938c8ad54 Btrfs: code cleanups for send/receive
Doing some code cleanups as suggested by Arne.
Changes do not change any logic.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:55 -04:00
Alexander Block
766702ef49 Btrfs: add/fix comments/documentation for send/receive
As the subject already said, add/fix comments.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:54 -04:00
Alexander Block
e479d9bb5f Btrfs: update send_progress at correct places
Updating send_progress in process_recorded_refs was not correct.
It got updated too early in the cur_inode_new_gen case.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Reported-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:53 -04:00
Alexander Block
34d73f54e2 Btrfs: make aux field of ulist 64 bit
Btrfs send/receive uses the aux field to store inode numbers. On
32 bit machines this may become a problem.

Also fix all users of ulist_add and ulist_add_merged.

Reported-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:53 -04:00
Alexander Block
7e0926fe5f Btrfs: fix use of radix_tree for name_cache in send/receive
We can't easily use the index of the radix tree for inums as the
radix tree uses 32bit indexes on 32bit kernels. For 32bit kernels,
we now use the lower 32bit of the inum as index and an additional
list to store multiple entries per radix tree entry.

Reported-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:52 -04:00
Alexander Block
17589bd96e Btrfs: fix memory leak for name_cache in send/receive
When everything is done, name_cache_free is called which however
forgot to call kfree on the cache entries.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:51 -04:00
Alexander Block
adbe7fb6c4 Btrfs: don't break in the final loop of find_extent_clone
If we break, we may miss the clone from send_root which we prefer
over all other clones.

Commit is a result of Arne's review.

Reported-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:50 -04:00
Alexander Block
52f9e53ede Btrfs: use normal return path for root == send_root case
Don't have a seperate return path for the mentioned case. Now
we do the same "take lowest inode/offset" logic for all found clones.

Commit is a result of Arne's review.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:50 -04:00
Alexander Block
35075bb046 Btrfs: use kmalloc instead of stack for backref_ctx
Make sure to never get in trouble due to the backref_ctx
which was on the stack before.

Commit is a result of Arne's review.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:49 -04:00
Alexander Block
ee849c0472 Btrfs: rename backref_ctx::found_in_send_root to found_itself
The new name should be easier to understand/read.

Commit is a result of Arne's review.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:48 -04:00
Alexander Block
d27aed5e24 Btrfs: remove unused use_list from send/receive code
use_list is a leftover and unused.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:48 -04:00
Alexander Block
ccf1626b49 Btrfs: add correct parent to check_dirs when dir got moved
We only added the parent for the new position of a moved dir.
We also need to add the old parent of the moved dir.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:47 -04:00
Alexander Block
9ea3ef516d Btrfs: remove unused code with #if 0
fs_path_remove is not used at the moment due to a previous patch.
Remove it for now (with #if 0) to avoid compile warnings.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:46 -04:00
Alexander Block
b9291affaa Btrfs: add missing check for dir != tmp_dir to is_first_ref
We missed that check which resultet in all refs with the same name
being reported as first_ref.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:45 -04:00
Alexander Block
1f4692da95 Btrfs: fix cur_ino < parent_ino case for send/receive
When the current inodes inum is smaller then the inum of the
parent directory strange things were happending due to wrong
path resolution and other bugs. Fix this with a new approach
for the problem.

Reported-by: Alex Lyakas <alex.bolshoy.btrfs@gmail.com>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:45 -04:00
Alexander Block
85a7b33b96 Btrfs: add rdev to get_inode_info in send/receive
We need rdev in the next commit.

Signed-off-by: Alexander Block <ablock84@googlemail.com>
2012-10-01 15:18:44 -04:00
Linus Torvalds
99dbb1632f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull the trivial tree from Jiri Kosina:
 "Tiny usual fixes all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
  doc: fix old config name of kprobetrace
  fs/fs-writeback.c: cleanup riteback_sb_inodes kerneldoc
  btrfs: fix the commment for the action flags in delayed-ref.h
  btrfs: fix trivial typo for the comment of BTRFS_FREE_INO_OBJECTID
  vfs: fix kerneldoc for generic_fh_to_parent()
  treewide: fix comment/printk/variable typos
  ipr: fix small coding style issues
  doc: fix broken utf8 encoding
  nfs: comment fix
  platform/x86: fix asus_laptop.wled_type module parameter
  mfd: printk/comment fixes
  doc: getdelays.c: remember to close() socket on error in create_nl_socket()
  doc: aliasing-test: close fd on write error
  mmc: fix comment typos
  dma: fix comments
  spi: fix comment/printk typos in spi
  Coccinelle: fix typo in memdup_user.cocci
  tmiofb: missing NULL pointer checks
  tools: perf: Fix typo in tools/perf
  tools/testing: fix comment / output typos
  ...
2012-10-01 09:06:36 -07:00
Al Viro
2903ff019b switch simple cases of fget_light to fdget
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 22:20:08 -04:00
Al Viro
8319aa9127 switch btrfs_ioctl_clone() to fget_light()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 21:10:09 -04:00
Al Viro
ecd188159e switch btrfs_ioctl_snap_create_transid() to fget_light()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 21:10:07 -04:00
Eric W. Biederman
2f2f43d3c7 userns: Convert btrfs to use kuid/kgid where appropriate
Cc: Chris Mason <chris.mason@fusionio.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-21 03:13:31 -07:00
Wang Sheng-Hui
44a075bde9 btrfs: fix the commment for the action flags in delayed-ref.h
The action field has been merged into struct btrfs_delayed_ref_node,
and no struct btrfs_delayed_ref is available now.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-09-21 08:07:12 +02:00
Eric W. Biederman
5f3a4a28ec userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr
- Pass the user namespace the uid and gid values in the xattr are stored
   in into posix_acl_from_xattr.

 - Pass the user namespace kuid and kgid values should be converted into
   when storing uid and gid values in an xattr in posix_acl_to_xattr.

- Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to
  pass in &init_user_ns.

In the short term this change is not strictly needed but it makes the
code clearer.  In the longer term this change is necessary to be able to
mount filesystems outside of the initial user namespace that natively
store posix acls in the linux xattr format.

Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-09-18 01:01:35 -07:00
Linus Torvalds
6167f81fd1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull a btrfs revert from Chris Mason:
 "My for-linus branch has one revert in the new quota code.

  We're building up more fixes at etc for the next merge window, but I'm
  keeping them out unless they are bigger regressions or have a huge
  impact."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Revert "Btrfs: fix some error codes in btrfs_qgroup_inherit()"
2012-09-16 12:58:44 -07:00
Chris Mason
f3a87f1b0c Revert "Btrfs: fix some error codes in btrfs_qgroup_inherit()"
This reverts commit 5986802c2f.

Both paths are not error paths but regular cases where non-qgroup
subvols are involved.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-09-14 20:06:30 -04:00
Wang Sheng-Hui
527a136138 btrfs: fix trivial typo for the comment of BTRFS_FREE_INO_OBJECTID
It should be storing, not sotring.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-09-06 11:11:14 +02:00
Liu Bo
8bad3c0244 btrfs: fix comment typo in btrfs_finish_ordered_io
Fix typo errors in comments of btrfs_finish_ordered_io.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-09-01 08:27:57 -07:00
Linus Torvalds
318e151019 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
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
  ...
2012-08-29 11:36:22 -07:00
Stefan Behrens
256dd1bb37 Btrfs: fix that repair code is spuriously executed for transid failures
If verify_parent_transid() fails for all mirrors, the current code
calls repair_io_failure() anyway which means:
- that the disk block is rewritten without repairing anything and
- that a kernel log message is printed which misleadingly claims
  that a read error was corrected.

This is an example:
parent transid verify failed on 615015833600 wanted 110423 found 110424
parent transid verify failed on 615015833600 wanted 110423 found 110424
btrfs read error corrected: ino 1 off 615015833600 (dev /dev/...)

It is wrong to ignore the results from verify_parent_transid() and to
call repair_eb_io_failure() when the verification of the transids failed.
This commit fixes the issue.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28 16:53:43 -04:00
Liu Bo
d280e5be94 Btrfs: fix ordered extent leak when failing to start a transaction
We cannot just return error before freeing ordered extent and releasing reserved
space when we fail to start a transacion.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28 16:53:42 -04:00
Liu Bo
24c03fa5cf Btrfs: fix a dio write regression
This bug is introduced by commit 3b8bde746f6f9bd36a9f05f5f3b6e334318176a9
(Btrfs: lock extents as we map them in DIO).

In dio write, we should unlock the section which we didn't do IO on in case that
we fall back to buffered write.  But we need to not only unlock the section
but also cleanup reserved space for the section.

This bug was found while running xfstests 133, with this 133 no longer complains.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28 16:53:41 -04:00
Josef Bacik
bd7de2c9a4 Btrfs: fix deadlock with freeze and sync V2
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>
2012-08-28 16:53:40 -04:00
Stefan Behrens
5ee0844d64 Btrfs: revert checksum error statistic which can cause a BUG()
Commit 442a4f6308 added btrfs device
statistic counters for detected IO and checksum errors to Linux 3.5.
The statistic part that counts checksum errors in
end_bio_extent_readpage() can cause a BUG() in a subfunction:
"kernel BUG at fs/btrfs/volumes.c:3762!"
That part is reverted with the current patch.
However, the counting of checksum errors in the scrub context remains
active, and the counting of detected IO errors (read, write or flush
errors) in all contexts remains active.

Cc: stable <stable@vger.kernel.org> # 3.5
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2012-08-28 16:53:39 -04:00
Stefan Behrens
68ce9682a4 Btrfs: remove superblock writing after fatal error
With commit acce952b0, btrfs was changed to flag the filesystem with
BTRFS_SUPER_FLAG_ERROR and switch to read-only mode after a fatal
error happened like a write I/O errors of all mirrors.
In such situations, on unmount, the superblock is written in
btrfs_error_commit_super(). This is done with the intention to be able
to evaluate the error flag on the next mount. A warning is printed
in this case during the next mount and the log tree is ignored.

The issue is that it is possible that the superblock points to a root
that was not written (due to write I/O errors).
The result is that the filesystem cannot be mounted. btrfsck also does
not start and all the other btrfs-progs tools fail to start as well.
However, mount -o recovery is working well and does the right things
to recover the filesystem (i.e., don't use the log root, clear the
free space cache and use the next mountable root that is stored in the
root backup array).

This patch removes the writing of the superblock when
BTRFS_SUPER_FLAG_ERROR is set, and removes the handling of the error
flag in the mount function.

These lines can be used to reproduce the issue (using /dev/sdm):
SCRATCH_DEV=/dev/sdm
SCRATCH_MNT=/mnt
echo 0 25165824 linear $SCRATCH_DEV 0 | dmsetup create foo
ls -alLF /dev/mapper/foo
mkfs.btrfs /dev/mapper/foo
mount /dev/mapper/foo $SCRATCH_MNT
echo bar > $SCRATCH_MNT/foo
sync
echo 0 25165824 error | dmsetup reload foo
dmsetup resume foo
ls -alF $SCRATCH_MNT
touch $SCRATCH_MNT/1
ls -alF $SCRATCH_MNT
sleep 35
echo 0 25165824 linear $SCRATCH_DEV 0 | dmsetup reload foo
dmsetup resume foo
sleep 1
umount $SCRATCH_MNT
btrfsck /dev/mapper/foo
dmsetup remove foo

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
2012-08-28 16:53:38 -04:00
Josef Bacik
ae1e206b80 Btrfs: allow delayed refs to be merged
Daniel Blueman reported a bug with fio+balance on a ramdisk setup.
Basically what happens is the balance relocates a tree block which will drop
the implicit refs for all of its children and adds a full backref.  Once the
block is relocated we have to add the implicit refs back, so when we cow the
block again we add the implicit refs for its children back.  The problem
comes when the original drop ref doesn't get run before we add the implicit
refs back.  The delayed ref stuff will specifically prefer ADD operations
over DROP to keep us from freeing up an extent that will have references to
it, so we try to add the implicit ref before it is actually removed and we
panic.  This worked fine before because the add would have just canceled the
drop out and we would have been fine.  But the backref walking work needs to
be able to freeze the delayed ref stuff in time so we have this ever
increasing sequence number that gets attached to all new delayed ref updates
which makes us not merge refs and we run into this issue.

So to fix this we need to merge delayed refs.  So everytime we run a
clustered ref we need to try and merge all of its delayed refs.  The backref
walking stuff locks the delayed ref head before processing, so if we have it
locked we are safe to merge any refs inside of the sequence number.  If
there is no sequence number we can merge all refs.  Doing this not only
fixes our bug but keeps the delayed ref code from adding and removing
useless refs and batching together multiple refs into one search instead of
one search per delayed ref, which will really help our commit times.  I ran
this with Daniels test and 276 and I haven't seen any problems.  Thanks,

Reported-by: Daniel J Blueman <daniel@quora.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-28 16:53:38 -04:00
Josef Bacik
5a24e84c55 Btrfs: fix enospc problems when deleting a subvol
Subvol delete is a special kind of awful where we use the global reserve to
cover the ENOSPC requirements.  The problem is once we're done removing
everything we do a btrfs_update_inode(), which by default will try to do the
delayed update stuff which will use it's own reserve.  There will be no
space in this reserve and we'll return ENOSPC.  So instead use
btrfs_update_inode_fallback() which will just fallback to updating the inode
item in the case of enospc.  This is fine because the global reserve covers
the space requirements for this.  With this patch I can now delete a subvol
on a problem image Dave Sterba sent me.  Thanks,

Reported-by: David Sterba <dave@jikos.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2012-08-28 16:53:37 -04:00