<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/fs/jbd/transaction.c, branch v2.6.35.8</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge branch 'for-next' into for-linus</title>
<updated>2010-03-08T15:55:37+00:00</updated>
<author>
<name>Jiri Kosina</name>
<email>jkosina@suse.cz</email>
</author>
<published>2010-03-08T15:55:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=318ae2edc3b29216abd8a2510f3f80b764f06858'/>
<id>318ae2edc3b29216abd8a2510f3f80b764f06858</id>
<content type='text'>
Conflicts:
	Documentation/filesystems/proc.txt
	arch/arm/mach-u300/include/mach/debug-macro.S
	drivers/net/qlge/qlge_ethtool.c
	drivers/net/qlge/qlge_main.c
	drivers/net/typhoon.c
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	Documentation/filesystems/proc.txt
	arch/arm/mach-u300/include/mach/debug-macro.S
	drivers/net/qlge/qlge_ethtool.c
	drivers/net/qlge/qlge_main.c
	drivers/net/typhoon.c
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: Delay discarding buffers in journal_unmap_buffer</title>
<updated>2010-03-04T23:20:26+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2010-02-16T19:37:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=86963918965eb8fe0c8ae009e7c1b4c630f533d5'/>
<id>86963918965eb8fe0c8ae009e7c1b4c630f533d5</id>
<content type='text'>
Delay discarding buffers in journal_unmap_buffer until
we know that "add to orphan" operation has definitely been
committed, otherwise the log space of committing transation
may be freed and reused before truncate get committed, updates
may get lost if crash happens.

This patch is a backport of JBD2 fix by dingdinghua &lt;dingdinghua@nrchpc.ac.cn&gt;.

Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Delay discarding buffers in journal_unmap_buffer until
we know that "add to orphan" operation has definitely been
committed, otherwise the log space of committing transation
may be freed and reused before truncate get committed, updates
may get lost if crash happens.

This patch is a backport of JBD2 fix by dingdinghua &lt;dingdinghua@nrchpc.ac.cn&gt;.

Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tree-wide: Assorted spelling fixes</title>
<updated>2010-02-09T10:13:56+00:00</updated>
<author>
<name>Daniel Mack</name>
<email>daniel@caiaq.de</email>
</author>
<published>2010-02-03T00:01:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3ad2f3fbb961429d2aa627465ae4829758bc7e07'/>
<id>3ad2f3fbb961429d2aa627465ae4829758bc7e07</id>
<content type='text'>
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.

Signed-off-by: Daniel Mack &lt;daniel@caiaq.de&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Junio C Hamano &lt;gitster@pobox.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.

Signed-off-by: Daniel Mack &lt;daniel@caiaq.de&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Junio C Hamano &lt;gitster@pobox.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: Annotate transaction start also for journal_restart()</title>
<updated>2009-09-16T15:44:10+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2009-08-11T15:27:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3adae9da0b35d2ca908039f42a1e90395c335181'/>
<id>3adae9da0b35d2ca908039f42a1e90395c335181</id>
<content type='text'>
lockdep annotation for a transaction start has been at the end of
journal_start(). But a transaction is also started from journal_restart(). Move
the lockdep annotation to start_this_handle() which covers both cases.

Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
lockdep annotation for a transaction start has been at the end of
journal_start(). But a transaction is also started from journal_restart(). Move
the lockdep annotation to start_this_handle() which covers both cases.

Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>JBD: round commit timer up to avoid uncommitted transaction</title>
<updated>2009-09-16T15:44:10+00:00</updated>
<author>
<name>Andreas Dilger</name>
<email>adilger@sun.com</email>
</author>
<published>2009-07-30T18:09:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b449fc6fcc07a392c69f3c1db9a4ad4dda8cbcba'/>
<id>b449fc6fcc07a392c69f3c1db9a4ad4dda8cbcba</id>
<content type='text'>
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
explicit sync/umount happens.

Signed-off-by: Andreas Dilger &lt;adilger@sun.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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
explicit sync/umount happens.

Signed-off-by: Andreas Dilger &lt;adilger@sun.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: Fix a race between checkpointing code and journal_get_write_access()</title>
<updated>2009-07-15T19:30:07+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2009-06-24T15:31:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1e9fd53b783ea646de3ee09a4574afeb6778d504'/>
<id>1e9fd53b783ea646de3ee09a4574afeb6778d504</id>
<content type='text'>
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
  __jbd_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. The similar problem can happen with
the journal_get_create_access() path.
  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 &lt;dingdinghua85@gmail.com&gt;.

Reported-by: dingdinghua &lt;dingdinghua85@gmail.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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
  __jbd_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. The similar problem can happen with
the journal_get_create_access() path.
  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 &lt;dingdinghua85@gmail.com&gt;.

Reported-by: dingdinghua &lt;dingdinghua85@gmail.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: clean up journal_try_to_free_buffers()</title>
<updated>2009-06-18T20:03:45+00:00</updated>
<author>
<name>Hisashi Hifumi</name>
<email>hifumi.hisashi@oss.ntt.co.jp</email>
</author>
<published>2009-06-17T23:26:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6f3f1cb21f08fbf757bbbbb0709ee515a7a7c6ad'/>
<id>6f3f1cb21f08fbf757bbbbb0709ee515a7a7c6ad</id>
<content type='text'>
I delete the following patch
"commit 3f31fddfa26b7594b44ff2b34f9a04ba409e0f91
Author: Mingming Cao &lt;cmm@us.ibm.com&gt;
Date:   Fri Jul 25 01:46:22 2008 -0700

    jbd: fix race between free buffer and commit transaction

This patch is no longer needed because if race between freeing buffer and
committing transaction functionality occurs and dio gets error, currently
dio falls back to buffered IO by the following patch.

	commit 6ccfa806a9cfbbf1cd43d5b6aa47ef2c0eb518fd
	Author: Hisashi Hifumi &lt;hifumi.hisashi@oss.ntt.co.jp&gt;
	Date:   Tue Sep 2 14:35:40 2008 -0700

   	VFS: fix dio write returning EIO when try_to_release_page fails

Signed-off-by: Hisashi Hifumi &lt;hifumi.hisashi@oss.ntt.co.jp&gt;
Cc: Theodore Tso &lt;tytso@mit.edu&gt;
Cc: Mingming Cao &lt;cmm@us.ibm.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I delete the following patch
"commit 3f31fddfa26b7594b44ff2b34f9a04ba409e0f91
Author: Mingming Cao &lt;cmm@us.ibm.com&gt;
Date:   Fri Jul 25 01:46:22 2008 -0700

    jbd: fix race between free buffer and commit transaction

This patch is no longer needed because if race between freeing buffer and
committing transaction functionality occurs and dio gets error, currently
dio falls back to buffered IO by the following patch.

	commit 6ccfa806a9cfbbf1cd43d5b6aa47ef2c0eb518fd
	Author: Hisashi Hifumi &lt;hifumi.hisashi@oss.ntt.co.jp&gt;
	Date:   Tue Sep 2 14:35:40 2008 -0700

   	VFS: fix dio write returning EIO when try_to_release_page fails

Signed-off-by: Hisashi Hifumi &lt;hifumi.hisashi@oss.ntt.co.jp&gt;
Cc: Theodore Tso &lt;tytso@mit.edu&gt;
Cc: Mingming Cao &lt;cmm@us.ibm.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext3: Use WRITE_SYNC for commits which are caused by fsync()</title>
<updated>2009-03-28T02:14:27+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2009-03-28T02:14:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=512a004382f2c60d5c4f855476ba965adc00250c'/>
<id>512a004382f2c60d5c4f855476ba965adc00250c</id>
<content type='text'>
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" &lt;tytso@mit.edu&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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" &lt;tytso@mit.edu&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: remove excess kernel-doc notation</title>
<updated>2009-01-08T16:31:01+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>randy.dunlap@oracle.com</email>
</author>
<published>2009-01-08T02:07:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1579c3a15c06055713b42b077b805f818638302c'/>
<id>1579c3a15c06055713b42b077b805f818638302c</id>
<content type='text'>
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 &lt;randy.dunlap@oracle.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;randy.dunlap@oracle.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: improve fsync batching</title>
<updated>2009-01-08T16:31:00+00:00</updated>
<author>
<name>Josef Bacik</name>
<email>jbacik@redhat.com</email>
</author>
<published>2009-01-08T02:07:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f420d4dc4272fd223986762df2ad06056ddebada'/>
<id>f420d4dc4272fd223986762df2ad06056ddebada</id>
<content type='text'>
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 &lt;jbacik@redhat.com&gt;
Cc: Andreas Dilger &lt;adilger@sun.com&gt;
Cc: Arjan van de Ven &lt;arjan@infradead.org&gt;
Cc: Ric Wheeler &lt;rwheeler@redhat.com&gt;
Cc: &lt;linux-ext4@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;jbacik@redhat.com&gt;
Cc: Andreas Dilger &lt;adilger@sun.com&gt;
Cc: Arjan van de Ven &lt;arjan@infradead.org&gt;
Cc: Ric Wheeler &lt;rwheeler@redhat.com&gt;
Cc: &lt;linux-ext4@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
