linux-toradex.git/fs/btrfs/check-integrity.c, branch v3.8.2

Btrfs: fix race in check-integrity caused by usage of bitfield

2012-12-17T01:46:13+00:00

The structure member mirror_num is modified concurrently to the
structure member is_iodone. This doesn't require any locking by
design, unless everything is stored in the same 32 bits of a
bit field. This was the case and xfstest 284 was able to
trigger false warnings from the checker code. This patch
seperates the bits and fixes the race.

Signed-off-by: Stefan Behrens 
Signed-off-by: Chris Mason

Btrfs: handle errors from btrfs_map_bio() everywhere

2012-12-12T22:15:40+00:00

With the addition of the device replace procedure, it is possible
for btrfs_map_bio(READ) to report an error. This happens when the
specific mirror is requested which is located on the target disk,
and the copy operation has not yet copied this block. Hence the
block cannot be read and this error state is indicated by
returning EIO.
Some background information follows now. A new mirror is added
while the device replace procedure is running.
btrfs_get_num_copies() returns one more, and
btrfs_map_bio(GET_READ_MIRROR) adds one more mirror if a disk
location is involved that was already handled by the device
replace copy operation. The assigned mirror num is the highest
mirror number, e.g. the value 3 in case of RAID1.
If btrfs_map_bio() is invoked with mirror_num == 0 (i.e., select
any mirror), the copy on the target drive is never selected
because that disk shall be able to perform the write requests as
quickly as possible. The parallel execution of read requests would
only slow down the disk copy procedure. Second case is that
btrfs_map_bio() is called with mirror_num > 0. This is done from
the repair code only. In this case, the highest mirror num is
assigned to the target disk, since it is used last. And when this
mirror is not available because the copy procedure has not yet
handled this area, an error is returned. Everywhere in the code
the handling of such errors is added now.

Signed-off-by: Stefan Behrens 
Signed-off-by: Chris Mason

Btrfs: pass fs_info to btrfs_map_block() instead of mapping_tree

2012-12-12T22:15:34+00:00

This is required for the device replace procedure in a later step.
Two calling functions also had to be changed to have the fs_info
pointer: repair_io_failure() and scrub_setup_recheck_block().

Signed-off-by: Stefan Behrens 
Signed-off-by: Chris Mason

Btrfs: Pass fs_info to btrfs_num_copies() instead of mapping_tree

2012-12-12T22:15:34+00:00

This is required for the device replace procedure in a later step.

Signed-off-by: Stefan Behrens 
Signed-off-by: Chris Mason

Btrfs: detect corrupted filesystem after write I/O errors

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

In check-integrity, detect when a superblock is written that points
to blocks that have not been written to disk due to I/O write errors.

Signed-off-by: Stefan Behrens

Btrfs: introduce subvol uuids and times

2012-07-25T21:28:38+00:00

This patch introduces uuids for subvolumes. Each
subvolume has it's own uuid. In case it was snapshotted,
it also contains parent_uuid. In case it was received,
it also contains received_uuid.

It also introduces subvolume ctime/otime/stime/rtime. The
first two are comparable to the times found in inodes. otime
is the origin/creation time and ctime is the change time.
stime/rtime are only valid on received subvolumes.
stime is the time of the subvolume when it was
sent. rtime is the time of the subvolume when it was
received.

Additionally to the times, we have a transid for each
time. They are updated at the same place as the times.

btrfs receive uses stransid and rtransid to find out
if a received subvolume changed in the meantime.

If an older kernel mounts a filesystem with the
extented fields, all fields become invalid. The next
mount with a new kernel will detect this and reset the
fields.

Signed-off-by: Alexander Block 
Reviewed-by: David Sterba 
Reviewed-by: Arne Jansen 
Reviewed-by: Jan Schmidt 
Reviewed-by: Alex Lyakas

Btrfs: use rcu to protect device->name

2012-06-15T01:29:16+00:00

Al pointed out that we can just toss out the old name on a device and add a
new one arbitrarily, so anybody who uses device->name in printk could
possibly use free'd memory.  Instead of adding locking around all of this he
suggested doing it with RCU, so I've introduced a struct rcu_string that
does just that and have gone through and protected all accesses to
device->name that aren't under the uuid_mutex with rcu_read_lock().  This
protects us and I will use it for dealing with removing the device that we
used to mount the file system in a later patch.  Thanks,

Reviewed-by: David Sterba 
Signed-off-by: Josef Bacik

Btrfs: fix false positive in check-integrity on unmount

2012-05-30T14:23:44+00:00

During unmount, it could happen that the integrity checker printed a
warning message "attempt to free ... on umount which is not yet iodone"
which turned out to be a false positive.

Signed-off-by: Stefan Behrens

Btrfs: fix runtime warning in check-integrity check data mode

2012-05-30T14:23:43+00:00

If a file_extent_item was located at the very end of a leaf and there was
not enough space to hold a full item, but there was enough space to hold
one of type BTRFS_FILE_EXTENT_INLINE or PREALLOC, and it was only such a
short item, a warning was printed anyway. This check is now fixed.

Signed-off-by: Stefan Behrens

Btrfs: change integrity checker to support big blocks

2012-05-11T14:56:40+00:00

The integrity checker used to be coded for nodesize == leafsize ==
sectorsize == PAGE_CACHE_SIZE.
This is now changed to support sizes for nodesize and leafsize which are
N * PAGE_CACHE_SIZE.

Signed-off-by: Stefan Behrens