linux-toradex.git/fs/jbd2/transaction.c, branch v2.6.33.9

jbd2: Annotate transaction start also for jbd2_journal_restart()

2009-08-18T01:23:17+00:00

lockdep annotation for a transaction start has been at the end of
jbd2_journal_start(). But a transaction is also started from
jbd2_journal_restart(). Move the lockdep annotation to start_this_handle()
which covers both cases.

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

jbd2: round commit timer up to avoid uncommitted transaction

2009-08-11T02:51:53+00:00

fix jiffie rounding in jbd commit timer setup code.  Rounding down
could cause the timer to be fired before the corresponding transaction
has expired.  That transaction can stay not committed forever if no
new transaction is created or expicit sync/umount happens.

Signed-off-by: Alex Zhuravlev (Tomas) 
Signed-off-by: Andreas Dilger 
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: 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"

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"

jbd2: Avoid possible NULL dereference in jbd2_journal_begin_ordered_truncate()

2009-02-10T16:15:34+00:00

If we race with commit code setting i_transaction to NULL, we could
possibly dereference it.  Proper locking requires the journal pointer
(to access journal->j_list_lock), which we don't have.  So we have to
change the prototype of the function so that filesystem passes us the
journal pointer.  Also add a more detailed comment about why the
function jbd2_journal_begin_ordered_truncate() does what it does and
how it should be used.

Thanks to Dan Carpenter  for pointing to the
suspitious code.

Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o" 
Acked-by: Joel Becker 
CC: linux-ext4@vger.kernel.org
CC: ocfs2-devel@oss.oracle.com
CC: mfasheh@suse.de
CC: Dan Carpenter

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2009-01-09T01:14:59+00:00

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (57 commits)
  jbd2: Fix oops in jbd2_journal_init_inode() on corrupted fs
  ext4: Remove "extents" mount option
  block: Add Kconfig help which notes that ext4 needs CONFIG_LBD
  ext4: Make printk's consistently prefixed with "EXT4-fs: "
  ext4: Add sanity checks for the superblock before mounting the filesystem
  ext4: Add mount option to set kjournald's I/O priority
  jbd2: Submit writes to the journal using WRITE_SYNC
  jbd2: Add pid and journal device name to the "kjournald2 starting" message
  ext4: Add markers for better debuggability
  ext4: Remove code to create the journal inode
  ext4: provide function to release metadata pages under memory pressure
  ext3: provide function to release metadata pages under memory pressure
  add releasepage hooks to block devices which can be used by file systems
  ext4: Fix s_dirty_blocks_counter if block allocation failed with nodelalloc
  ext4: Init the complete page while building buddy cache
  ext4: Don't allow new groups to be added during block allocation
  ext4: mark the blocks/inode bitmap beyond end of group as used
  ext4: Use new buffer_head flag to check uninit group bitmaps initialization
  ext4: Fix the race between read_inode_bitmap() and ext4_new_inode()
  ext4: code cleanup
  ...

jbd2: Add buffer triggers

2009-01-05T16:40:30+00:00

Filesystems often to do compute intensive operation on some
metadata.  If this operation is repeated many times, it can be very
expensive.  It would be much nicer if the operation could be performed
once before a buffer goes to disk.

This adds triggers to jbd2 buffer heads.  Just before writing a metadata
buffer to the journal, jbd2 will optionally call a commit trigger associated
with the buffer.  If the journal is aborted, an abort trigger will be
called on any dirty buffers as they are dropped from pending
transactions.

ocfs2 will use this feature.

Initially I tried to come up with a more generic trigger that could be
used for non-buffer-related events like transaction completion.  It
doesn't tie nicely, because the information a buffer trigger needs
(specific to a journal_head) isn't the same as what a transaction
trigger needs (specific to a tranaction_t or perhaps journal_t).  So I
implemented a buffer set, with the understanding that
journal/transaction wide triggers should be implemented separately.

There is only one trigger set allowed per buffer.  I can't think of any
reason to attach more than one set.  Contrast this with a journal or
transaction in which multiple places may want to watch the entire
transaction separately.

The trigger sets are considered static allocation from the jbd2
perspective.  ocfs2 will just have one trigger set per block type,
setting the same set on every bh of the same type.

Signed-off-by: Joel Becker 
Cc: "Theodore Ts'o" 
Cc: 
Signed-off-by: Mark Fasheh

ext4: add fsync batch tuning knobs

2009-01-04T01:27:38+00:00

Add new mount options, min_batch_time and max_batch_time, which
controls how long the jbd2 layer should wait for additional filesystem
operations to get batched with a synchronous write transaction.

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

jbd2: improve jbd2 fsync batching

2008-11-26T06:14:26+00:00

This patch removes the static sleep time in favor of a more self
optimizing approach where we measure the average amount of time it
takes to commit a transaction to disk and the ammount of time a
transaction has been running.  If somebody does a sync write or an
fsync() traditionally we would sleep for 1 jiffies, which depending on
the value of HZ could be a significant amount of time compared to how
long it takes to commit a transaction to the underlying storage.  With
this patch instead of sleeping for a jiffie, we check to see if the
amount of time this transaction has been running is less than the
average commit time, and if it is we sleep for the delta using
schedule_hrtimeout to give us a higher precision sleep time.  This
greatly benefits high end storage where you could end up sleeping for
longer than it takes to commit the transaction and therefore sitting
idle instead of allowing the transaction to be committed by keeping
the sleep time to a minimum so you are sure to always be doing
something.

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