linux.git/fs/jbd2, branch v2.6.31

jbd2: fix race between write_metadata_buffer and get_write_access

2009-07-13T21:55:35+00:00

The function jbd2_journal_write_metadata_buffer() calls
jbd_unlock_bh_state(bh_in) too early; this could potentially allow
another thread to call get_write_access on the buffer head, modify the
data, and dirty it, and allowing the wrong data to be written into the
journal.  Fortunately, if we lose this race, the only time this will
actually cause filesystem corruption is if there is a system crash or
other unclean shutdown of the system before the next commit can take
place.

Signed-off-by: dingdinghua 
Signed-off-by: "Theodore Ts'o"

jbd2: Fix a race between checkpointing code and journal_get_write_access()

2009-07-13T20:16:20+00:00

The following race can happen:

 CPU1                          CPU2
                               checkpointing code checks the buffer, adds
                                 it to an array for writeback
 do_get_write_access()
 ...
 lock_buffer()
 unlock_buffer()
                               flush_batch() submits the buffer for IO
 __jbd2_journal_file_buffer()

So a buffer under writeout is returned from
do_get_write_access(). Since the filesystem code relies on the fact
that journaled buffers cannot be written out, it does not take the
buffer lock and so it can modify buffer while it is under
writeout. That can lead to a filesystem corruption if we crash at the
right moment.

We fix the problem by clearing the buffer dirty bit under buffer_lock
even if the buffer is on BJ_None list. Actually, we clear the dirty
bit regardless the list the buffer is in and warn about the fact if
the buffer is already journalled.

Thanks for spotting the problem goes to dingdinghua .

Reported-by: dingdinghua 
Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o"

jbd2: Remove GFP_ATOMIC kmalloc from inside spinlock critical region

2009-06-21T03:34:44+00:00

Fix jbd2_dev_to_name(), a function used when pretty-printting jbd2 and
ext4 tracepoints.

Signed-off-by: "Theodore Ts'o"

jbd2: clean up jbd2_journal_try_to_free_buffers()

2009-06-18T00:08:51+00:00

This patch reverts 3f31fddf, which is no longer needed because if a
race between freeing buffer and committing transaction functionality
occurs and dio gets error, currently dio falls back to buffered IO due
to the commit 6ccfa806.

Signed-off-by: Hisashi Hifumi 
Cc: Mingming Cao 
Acked-by: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: "Theodore Ts'o"

jbd2: convert instrumentation from markers to tracepoints

2009-06-17T15:47:48+00:00

Signed-off-by: "Theodore Ts'o"

jbd2: Fix minor typos in comments in fs/jbd2/journal.c

2009-06-09T04:06:20+00:00

Signed-off-by: Alberto Bertogli 
Signed-off-by: Theodore Ts'o

jbd2: use SWRITE_SYNC_PLUG when writing synchronous revoke records

2009-04-14T11:50:56+00:00

The revoke records must be written using the same way as the rest of
the blocks during the commit process; that is, either marked as
synchronous writes or as asynchornous writes.

Signed-off-by: "Theodore Ts'o"

jbd2: use WRITE_SYNC_PLUG instead of WRITE_SYNC

2009-04-06T15:04:54+00:00

When you are going to be submitting several sync writes, we want to
give the IO scheduler a chance to merge some of them. Instead of
using the implicitly unplugging WRITE_SYNC variant, use WRITE_SYNC_PLUG
and rely on sync_buffer() doing the unplug when someone does a
wait_on_buffer()/lock_buffer().

Signed-off-by: Jens Axboe 
Signed-off-by: Linus Torvalds

jbd2: Update locking coments

2009-03-27T21:20:40+00:00

Update information about locking in JBD2 revoke code. Inconsistency in
comments found by Lin Tan .

CC: Lin Tan .
Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o"

ext4: Use WRITE_SYNC for commits which are caused by fsync()

2009-03-26T03:35:46+00:00

If a commit is triggered by fsync(), set a flag indicating the journal
blocks associated with the transaction should be flushed out using
WRITE_SYNC.

Signed-off-by: "Theodore Ts'o"