linux.git/fs/jbd2/commit.c, branch v2.6.28

jbd2: Call the commit callback before the transaction could get dropped

2008-10-29T01:08:20+00:00

The transaction can potentially get dropped if there are no buffers
that need to be written.  Make sure we call the commit callback before
potentially deciding to drop the transaction.  Also avoid
dereferencing the commit_transaction pointer in the marker for the
same reason.

This patch fixes the bug reported by Eric Paris at:
http://bugzilla.kernel.org/show_bug.cgi?id=11838

Signed-off-by: "Theodore Ts'o" 
Acked-by: Eric Sandeen 
Tested-by: Eric Paris

ext4: Replace hackish ext4_mb_poll_new_transaction with commit callback

2008-10-17T00:00:24+00:00

The multiblock allocator needs to be able to release blocks (and issue
a blkdev discard request) when the transaction which freed those
blocks is committed.  Previously this was done via a polling mechanism
when blocks are allocated or freed.  A much better way of doing things
is to create a jbd2 callback function and attaching the list of blocks
to be freed directly to the transaction structure.

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

ext4: add an option to control error handling on file data

2008-10-11T02:12:43+00:00

If the journal doesn't abort when it gets an IO error in file data
blocks, the file data corruption will spread silently.  Because
most of applications and commands do buffered writes without fsync(),
they don't notice the IO error.  It's scary for mission critical
systems.  On the other hand, if the journal aborts whenever it gets
an IO error in file data blocks, the system will easily become
inoperable.  So this patch introduces a filesystem option to
determine whether it aborts the journal or just call printk() when
it gets an IO error in file data.

If you mount an ext4 fs with data_err=abort option, it aborts on file
data write error.  If you mount it with data_err=ignore, it doesn't
abort, just call printk().  data_err=ignore is the default.

Here is the corresponding patch of the ext3 version:
http://kerneltrap.org/mailarchive/linux-kernel/2008/9/9/3239374

Signed-off-by: Hidehiro Kawai 
Signed-off-by: Theodore Ts'o

jbd2: don't dirty original metadata buffer on abort

2008-10-11T00:29:31+00:00

Currently, original metadata buffers are dirtied when they are
unfiled whether the journal has aborted or not.  Eventually these
buffers will be written-back to the filesystem by pdflush.  This
means some metadata buffers are written to the filesystem without
journaling if the journal aborts.  So if both journal abort and
system crash happen at the same time, the filesystem would become
inconsistent state.  Additionally, replaying journaled metadata
can overwrite the latest metadata on the filesystem partly.
Because, if the journal gets aborted, journaled metadata are
preserved and replayed during the next mount not to lose
uncheckpointed metadata.  This would also break the consistency
of the filesystem.

This patch prevents original metadata buffers from being dirtied
on abort by clearing BH_JBDDirty flag from those buffers.  Thus,
no metadata buffers are written to the filesystem without journaling.

Signed-off-by: Hidehiro Kawai 
Signed-off-by: Theodore Ts'o

jbd2: abort when failed to log metadata buffers

2008-10-12T20:39:16+00:00

If we failed to write metadata buffers to the journal space and
succeeded to write the commit record, stale data can be written
back to the filesystem as metadata in the recovery phase.

To avoid this, when we failed to write out metadata buffers,
abort the journal before writing the commit record.

We can also avoid this kind of corruption by using the journal
checksum feature because it can detect invalid metadata blocks in the
journal and avoid them from being replayed.  So we don't need to care
about asynchronous commit record writeout with a checksum.

Signed-off-by: Hidehiro Kawai 
Signed-off-by: Theodore Ts'o

jbd2: Fix buffer head leak when writing the commit block

2008-10-06T16:04:02+00:00

Also make sure the buffer heads are marked clean before submitting bh
for writing.  The previous code was marking the buffer head dirty,
which would have forced an unneeded write (and seek) to the journal
for no good reason.

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

ext4: Add debugging markers that can be used by systemtap

2008-10-06T00:50:06+00:00

This debugging markers are designed to debug problems such as the
random filesystem latency problems reported by Arjan.

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

jbd2: clean up how the journal device name is printed

2008-09-16T18:36:17+00:00

Calculate the journal device name once and stash it away in the
journal_s structure.  This avoids needing to call bdevname()
everywhere and reduces stack usage by not needing to allocate an
on-stack buffer.  In addition, we eliminate the '/' that can appear in
device names (e.g. "cciss/c0d0p9" --- see kernel bugzilla #11321) that
can cause problems when creating proc directory names, and include the
inode number to support ocfs2 which creates multiple journals with
different inode numbers.

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

mm: rename page trylock

2008-08-05T04:31:34+00:00

Converting page lock to new locking bitops requires a change of page flag
operation naming, so we might as well convert it to something nicer
(!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked).

This also facilitates lockdeping of page lock.

Signed-off-by: Nick Piggin 
Acked-by: KOSAKI Motohiro 
Acked-by: Peter Zijlstra 
Acked-by: Andrew Morton 
Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Linus Torvalds

jbd2: don't abort if flushing file data failed

2008-08-01T02:26:04+00:00

In ordered mode, the current jbd2 aborts the journal if a file data buffer
has an error.  But this behavior is unintended, and we found that it has
been adopted accidentally.

This patch undoes it and just calls printk() instead of aborting the
journal.  Unlike a similar patch for ext3/jbd, file data buffers are
written via generic_writepages().  But we also need to set AS_EIO
into their mappings because wait_on_page_writeback_range() clears
AS_EIO before a user process sees it.

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