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 <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'ext3-latency-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext3: Add replace-on-rename hueristics for data=writeback mode
ext3: Add replace-on-truncate hueristics for data=writeback mode
ext3: Use WRITE_SYNC for commits which are caused by fsync()
block_write_full_page: Use synchronous writes for WBC_SYNC_ALL writebacks
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" <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
journal_start_commit() returns 1 if either a transaction is committing or
the function has queued a transaction commit. But it returns 0 if we
raced with somebody queueing the transaction commit as well. This
resulted in ext3_sync_fs() not functioning correctly (description from
Arthur Jones): In the case of a data=ordered umount with pending long
symlinks which are delayed due to a long list of other I/O on the backing
block device, this causes the buffer associated with the long symlinks to
not be moved to the inode dirty list in the second phase of fsync_super.
Then, before they can be dirtied again, kjournald exits, seeing the UMOUNT
flag and the dirty pages are never written to the backing block device,
causing long symlink corruption and exposing new or previously freed block
data to userspace.
This can be reproduced with a script created by Eric Sandeen
<sandeen@redhat.com>:
#!/bin/bash
umount /mnt/test2
mount /dev/sdb4 /mnt/test2
rm -f /mnt/test2/*
dd if=/dev/zero of=/mnt/test2/bigfile bs=1M count=512
touch /mnt/test2/thisisveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename
ln -s /mnt/test2/thisisveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename
/mnt/test2/link
umount /mnt/test2
mount /dev/sdb4 /mnt/test2
ls /mnt/test2/
This patch fixes journal_start_commit() to always return 1 when there's
a transaction committing or queued for commit.
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Mike Snitzer <snitzer@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove excess kernel-doc from fs/jbd/transaction.c:
Warning(linux-2.6.28-git5//fs/jbd/transaction.c:764): Excess function parameter 'credits' description in 'journal_get_write_access'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a flaw with the way jbd handles fsync batching. If we fsync() a
file and we were not the last person to run fsync() on this fs then we
automatically sleep for 1 jiffie in order to wait for new writers to join
into the transaction before forcing the commit. The problem with this is
that with really fast storage (ie a Clariion) the time it takes to commit
a transaction to disk is way faster than 1 jiffie in most cases, so
sleeping means waiting longer with nothing to do than if we just committed
the transaction and kept going. Ric Wheeler noticed this when using
fs_mark with more than 1 thread, the throughput would plummet as he added
more threads.
This patch attempts to fix this problem by recording the average time in
nanoseconds that it takes to commit a transaction to disk, and what time
we started the transaction. If we run an fsync() and we have been running
for less time than it takes to commit the transaction to disk, we sleep
for the delta amount of time and then commit to disk. We acheive
sub-jiffie sleeping using schedule_hrtimeout. This means that the wait
time is auto-tuned to the speed of the underlying disk, instead of having
this static timeout. I weighted the average according to somebody's
comments (Andreas Dilger I think) in order to help normalize random
outliers where we take way longer or way less time to commit than the
average. I also have a min() check in there to make sure we don't sleep
longer than a jiffie in case our storage is super slow, this was requested
by Andrew.
I unfortunately do not have access to a Clariion, so I had to use a
ramdisk to represent a super fast array. I tested with a SATA drive with
barrier=1 to make sure there was no regression with local disks, I tested
with a 4 way multipathed Apple Xserve RAID array and of course the
ramdisk. I ran the following command
fs_mark -d /mnt/ext3-test -s 4096 -n 2000 -D 64 -t $i
where $i was 2, 4, 8, 16 and 32. I mkfs'ed the fs each time. Here are my
results
type threads with patch without patch
sata 2 24.6 26.3
sata 4 49.2 48.1
sata 8 70.1 67.0
sata 16 104.0 94.1
sata 32 153.6 142.7
xserve 2 246.4 222.0
xserve 4 480.0 440.8
xserve 8 829.5 730.8
xserve 16 1172.7 1026.9
xserve 32 1816.3 1650.5
ramdisk 2 2538.3 1745.6
ramdisk 4 2942.3 661.9
ramdisk 8 2882.5 999.8
ramdisk 16 2738.7 1801.9
ramdisk 32 2541.9 2394.0
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ric Wheeler <rwheeler@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit be07c4ed introducd a regression because it assumed that if
there were no transactions ready to be checkpointed, that no progress
could be made on making space available in the journal, and so the
journal should be aborted. This assumption is false; it could be the
case that simply calling cleanup_journal_tail() will recover the
necessary space, or, for small journals, the currently committing
transaction could be responsible for chewing up the required space in
the log, so we need to wait for the currently committing transaction
to finish before trying to force a checkpoint operation.
This patch fixes the bug reported by Meelis Roos at:
http://bugzilla.kernel.org/show_bug.cgi?id=11937
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Duane Griffin <duaneg@dghda.com>
Cc: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Delete excess kernel-doc notation in fs/ subdirectory:
Warning(linux-2.6.27-git10//fs/jbd/transaction.c:886): Excess function parameter or struct member 'credits' description in 'journal_get_undo_access'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The __log_wait_for_space function sits in a loop checkpointing
transactions until there is sufficient space free in the journal.
However, if there are no transactions to be processed (e.g. because the
free space calculation is wrong due to a corrupted filesystem) it will
never progress.
Check for space being required when no transactions are outstanding and
abort the journal instead of endlessly looping.
This patch fixes the bug reported by Sami Liedes at:
http://bugzilla.kernel.org/show_bug.cgi?id=10976
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Tested-by: Sami Liedes <sliedes@cc.hut.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__try_to_free_cp_buf(), __process_buffer(), and __wait_cp_io() test
BH_Uptodate flag to detect write I/O errors on metadata buffers. But by
commit 95450f5a7e "ext3: don't read inode
block if the buffer has a write error"(*), BH_Uptodate flag can be set to
inode buffers with BH_Write_EIO in order to avoid reading old inode data.
So now, we have to test BH_Write_EIO flag of checkpointing inode buffers
instead of BH_Uptodate. This patch does it.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a checkpointing IO fails, current JBD code doesn't check the error
and continue journaling. This means latest metadata can be lost from both
the journal and filesystem.
This patch leaves the failed metadata blocks in the journal space and
aborts journaling in the case of log_do_checkpoint(). To achieve this, we
need to do:
1. don't remove the failed buffer from the checkpoint list where in
the case of __try_to_free_cp_buf() because it may be released or
overwritten by a later transaction
2. log_do_checkpoint() is the last chance, remove the failed buffer
from the checkpoint list and abort the journal
3. when checkpointing fails, don't update the journal super block to
prevent the journaled contents from being cleaned. For safety,
don't update j_tail and j_tail_sequence either
4. when checkpointing fails, notify this error to the ext3 layer so
that ext3 don't clear the needs_recovery flag, otherwise the
journaled contents are ignored and cleaned in the recovery phase
5. if the recovery fails, keep the needs_recovery flag
6. prevent cleanup_journal_tail() from being called between
__journal_drop_transaction() and journal_abort() (a race issue
between journal_flush() and __log_wait_for_space()
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use fs/*/Kconfig more, which is good because everything related to one
filesystem is in one place and fs/Kconfig is quite fat.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In ordered mode, if a file data buffer being dirtied exists in the
committing transaction, we write the buffer to the disk, move it from the
committing transaction to the running transaction, then dirty it. But we
don't have to remove the buffer from the committing transaction when the
buffer couldn't be written out, otherwise it would miss the error and the
committing transaction would not abort.
This patch adds an error check before removing the buffer from the
committing transaction.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 a ext3 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.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 aborts, 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 <hidehiro.kawai.ez@hitachi.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
the names were too generic:
drivers/uio/uio.c:87: error: expected identifier or '(' before 'do'
drivers/uio/uio.c:87: error: expected identifier or '(' before 'while'
drivers/uio/uio.c:113: error: 'map_release' undeclared here (not in a function)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Most the free-standing lock_acquire() usages look remarkably similar, sweep
them into a new helper.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Like the page lock change, this also requires name change, so convert the
raw test_and_set bitop to a trylock.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <npiggin@suse.de>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In ordered mode, the current jbd 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. Additionally, set AS_EIO into the address_space object of the
failed buffer which is submitted by journal_do_submit_data() so that
fsync() can get -EIO.
Missing error checkings are also added to inform errors on file data
buffers to the user. The following buffers are targeted.
(a) the buffer which has already been written out by pdflush
(b) the buffer which has been unlocked before scanned in the
t_locked_list loop
[akpm@linux-foundation.org: improve grammar in a printk]
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After ext3-ordered files are truncated, there is a possibility that the
pages which cannot be estimated still remain. Remaining pages can be
released when the system has really few memory. So, it is not memory
leakage. But the resource management software etc. may not work
correctly.
It is possible that journal_unmap_buffer() cannot release the buffers, and
the pages to which they belong because they are attached to a commiting
transaction and journal_unmap_buffer() cannot release them. To release
such the buffers and the pages later, journal_unmap_buffer() leaves it to
journal_commit_transaction(). (journal_unmap_buffer() puts the mark
'BH_Freed' to the buffers so that journal_commit_transaction() can
identify whether they can be released or not.)
In the journalled mode and the writeback mode, jbd does with only metadata
buffers. But in the ordered mode, jbd does with metadata buffers and also
data buffers.
Actually, journal_commit_transaction() releases only the metadata buffers
of which release is demanded by journal_unmap_buffer(), and also releases
the pages to which they belong if possible.
As a result, the data buffers of which release is demanded by
journal_unmap_buffer() remain after a transaction commits. And also the
pages to which they belong remain.
Such the remained pages don't have mapping any longer. Due to this fact,
there is a possibility that the pages which cannot be estimated remain.
The metadata buffers marked 'BH_Freed' and the pages to which
they belong can be released at 'JBD: commit phase 7'.
Therefore, by applying the same code into 'JBD: commit phase 2' (where the
data buffers are done with), journal_commit_transaction() can also release
the data buffers marked 'BH_Freed' and the pages to which they belong.
As a result, all the buffers marked 'BH_Freed' can be released, and also
all the pages to which these buffers belong can be released at
journal_commit_transaction(). So, the page which cannot be estimated is
lost.
<<Excerpt of code at 'JBD: commit phase 7'>>
> spin_lock(&journal->j_list_lock);
> while (commit_transaction->t_forget) {
> transaction_t *cp_transaction;
> struct buffer_head *bh;
>
> jh = commit_transaction->t_forget;
>...
> if (buffer_freed(bh)) {
> ^^^^^^^^^^^^^^^^^^^^^^^^
> clear_buffer_freed(bh);
> ^^^^^^^^^^^^^^^^^^^^^^^^
> clear_buffer_jbddirty(bh);
> }
>
> if (buffer_jbddirty(bh)) {
> JBUFFER_TRACE(jh, "add to new checkpointing trans");
> __journal_insert_checkpoint(jh, commit_transaction);
> JBUFFER_TRACE(jh, "refile for checkpoint writeback");
> __journal_refile_buffer(jh);
> jbd_unlock_bh_state(bh);
> } else {
> J_ASSERT_BH(bh, !buffer_dirty(bh));
> ...
> JBUFFER_TRACE(jh, "refile or unfile freed buffer");
> __journal_refile_buffer(jh);
> if (!jh->b_transaction) {
> jbd_unlock_bh_state(bh);
> /* needs a brelse */
> journal_remove_journal_head(bh);
> release_buffer_page(bh);
> ^^^^^^^^^^^^^^^^^^^^^^^^
> } else
> }
****************************************************************
* Apply the code of "^^^^^^" lines into 'JBD: commit phase 2' *
****************************************************************
At journal_commit_transaction() code, there is one extra message in the
series of jbd debug messages. ("JBD: commit phase 2") This patch fixes
it, too.
Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jens Axboe
Linus Torvalds
Jan Kara
Theodore Ts'o
Randy Dunlap
Josef Bacik
Duane Griffin
Hidehiro Kawai
Alexey Dobriyan
Ingo Molnar
Peter Zijlstra
Nick Piggin
Toshiyuki Okajima
Adrian Bunk