linux-toradex.git/fs/btrfs/disk-io.h, branch v3.7.4

Btrfs: make filesystem read-only when submitting barrier fails

2012-10-09T13:20:19+00:00

So far the return code of barrier_all_devices() is ignored, which
means that errors are ignored. The result can be a corrupt
filesystem which is not consistent.
This commit adds code to evaluate the return code of
barrier_all_devices(). The normal btrfs_error() mechanism is used to
switch the filesystem into read-only mode when errors are detected.

In order to decide whether barrier_all_devices() should return
error or success, the number of disks that are allowed to fail the
barrier submission is calculated. This calculation accounts for the
worst RAID level of metadata, system and data. If single, dup or
RAID0 is in use, a single disk error is already considered to be
fatal. Otherwise a single disk error is tolerated.

The calculation of the number of disks that are tolerated to fail
the barrier operation is performed when the filesystem gets mounted,
when a balance operation is started and finished, and when devices
are added or removed.

Signed-off-by: Stefan Behrens

Btrfs: remove superblock writing after fatal error

2012-08-28T20:53:38+00:00

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 
Signed-off-by: Jan Schmidt

Btrfs: added helper to create new trees

2012-07-10T13:14:43+00:00

This creates a brand new tree. Will be used to create
the quota tree.

Signed-off-by: Arne Jansen

btrfs: Drop unused function btrfs_abort_devices()

2012-05-30T14:23:39+00:00

1) This function is not used anywhere.

2) Using the blk_abort_queue() to abort the queue seems not correct.
blk_abort_queue() is used for timeout handling (block/blk-timeout.c).

Cc: Chris Mason 
Cc: linux-btrfs@vger.kernel.org
Cc: Jens Axboe 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Asias He

Btrfs: avoid sleeping in verify_parent_transid while atomic

2012-05-06T11:23:47+00:00

verify_parent_transid needs to lock the extent range to make
sure no IO is underway, and so it can safely clear the
uptodate bits if our checks fail.

But, a few callers are using it with spinlocks held.  Most
of the time, the generation numbers are going to match, and
we don't want to switch to a blocking lock just for the error
case.  This adds an atomic flag to verify_parent_transid,
and changes it to return EAGAIN if it needs to block to
properly verifiy things.

Signed-off-by: Chris Mason

btrfs: enhance transaction abort infrastructure

2012-03-22T00:45:40+00:00

Signed-off-by: Jeff Mahoney

btrfs: return void in functions without error conditions

2012-03-22T00:45:34+00:00

Signed-off-by: Jeff Mahoney

btrfs: clean_tree_block should panic on observed memory corruption and return void

2012-03-22T00:45:31+00:00

 The only error condition in clean_tree_block is an accounting bug.
 Returning without modifying dirty_metadata_bytes and as if the cleaning
 as been performed may cause problems later so it should panic instead.

 It should probably be a BUG_ON but we have btrfs_panic now.

Signed-off-by: Jeff Mahoney

btrfs: take allocation of ->tree_root into open_ctree()

2012-01-09T00:37:02+00:00

now that we don't need it for sget() anymore...

Signed-off-by: Al Viro

btrfs: make open_ctree() return int

2012-01-09T00:34:39+00:00

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: Al Viro