<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/fs/jbd, branch v2.6.27.12</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>jbd: test BH_Write_EIO to detect errors on metadata buffers</title>
<updated>2008-12-13T23:29:16+00:00</updated>
<author>
<name>Hidehiro Kawai</name>
<email>hidehiro.kawai.ez@hitachi.com</email>
</author>
<published>2008-10-22T21:15:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=eb6abcfe147282b257b5411a31a91ae1d083ec82'/>
<id>eb6abcfe147282b257b5411a31a91ae1d083ec82</id>
<content type='text'>
commit 9f818b4ac04f53458d0354950b4f229f54be4dbf upstream.

__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 95450f5a7e53d5752ce1a0d0b8282e10fe745ae0 "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 &lt;hidehiro.kawai.ez@hitachi.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&gt;
Acked-by: Eric Sandeen &lt;sandeen@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9f818b4ac04f53458d0354950b4f229f54be4dbf upstream.

__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 95450f5a7e53d5752ce1a0d0b8282e10fe745ae0 "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 &lt;hidehiro.kawai.ez@hitachi.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&gt;
Acked-by: Eric Sandeen &lt;sandeen@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: fix error handling for checkpoint io</title>
<updated>2008-12-13T23:29:15+00:00</updated>
<author>
<name>Hidehiro Kawai</name>
<email>hidehiro.kawai.ez@hitachi.com</email>
</author>
<published>2008-10-22T21:15:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b43a0b325c7e28db51c3f4a0aaa8499518fa9b3b'/>
<id>b43a0b325c7e28db51c3f4a0aaa8499518fa9b3b</id>
<content type='text'>
commit 4afe978530702c934dfdb11f54073136818b2119 upstream.

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 &lt;hidehiro.kawai.ez@hitachi.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&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;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 4afe978530702c934dfdb11f54073136818b2119 upstream.

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 &lt;hidehiro.kawai.ez@hitachi.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&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;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: ordered data integrity fix</title>
<updated>2008-12-05T18:55:47+00:00</updated>
<author>
<name>Hidehiro Kawai</name>
<email>hidehiro.kawai.ez@hitachi.com</email>
</author>
<published>2008-10-19T03:27:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ddb18c699bb0ecf636113acee2ad25b201d2bb12'/>
<id>ddb18c699bb0ecf636113acee2ad25b201d2bb12</id>
<content type='text'>
commit 960a22ae60c8a723bd17da3b929fe0bcea6d007e upstream.

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 &lt;hidehiro.kawai.ez@hitachi.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;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 960a22ae60c8a723bd17da3b929fe0bcea6d007e upstream.

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 &lt;hidehiro.kawai.ez@hitachi.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;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'core/locking' into core/urgent</title>
<updated>2008-08-11T22:11:49+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2008-08-11T22:11:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=23a0ee908cbfba3264d19729c67c22b20fa73886'/>
<id>23a0ee908cbfba3264d19729c67c22b20fa73886</id>
<content type='text'>
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
</pre>
</div>
</content>
</entry>
<entry>
<title>lockdep: rename map_[acquire|release]() =&gt; lock_map_[acquire|release]()</title>
<updated>2008-08-11T08:30:30+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2008-08-11T08:30:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3295f0ef9ff048a4619ede597ad9ec9cab725654'/>
<id>3295f0ef9ff048a4619ede597ad9ec9cab725654</id>
<content type='text'>
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 &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>lockdep: map_acquire</title>
<updated>2008-08-11T07:30:23+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>a.p.zijlstra@chello.nl</email>
</author>
<published>2008-08-11T07:30:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4f3e7524b2e703d9f8b02ac338153a53dd7ede66'/>
<id>4f3e7524b2e703d9f8b02ac338153a53dd7ede66</id>
<content type='text'>
Most the free-standing lock_acquire() usages look remarkably similar, sweep
them into a new helper.

Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Most the free-standing lock_acquire() usages look remarkably similar, sweep
them into a new helper.

Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs: rename buffer trylock</title>
<updated>2008-08-05T04:56:09+00:00</updated>
<author>
<name>Nick Piggin</name>
<email>npiggin@suse.de</email>
</author>
<published>2008-08-02T10:02:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ca5de404ff036a29b25e9a83f6919c9f606c5841'/>
<id>ca5de404ff036a29b25e9a83f6919c9f606c5841</id>
<content type='text'>
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 &lt;npiggin@suse.de&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>
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 &lt;npiggin@suse.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: rename page trylock</title>
<updated>2008-08-05T04:31:34+00:00</updated>
<author>
<name>Nick Piggin</name>
<email>npiggin@suse.de</email>
</author>
<published>2008-08-02T10:01:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=529ae9aaa08378cfe2a4350bded76f32cc8ff0ce'/>
<id>529ae9aaa08378cfe2a4350bded76f32cc8ff0ce</id>
<content type='text'>
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 =&gt; trylock_page, SetPageLocked =&gt; set_page_locked).

This also facilitates lockdeping of page lock.

Signed-off-by: Nick Piggin &lt;npiggin@suse.de&gt;
Acked-by: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Acked-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Acked-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.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>
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 =&gt; trylock_page, SetPageLocked =&gt; set_page_locked).

This also facilitates lockdeping of page lock.

Signed-off-by: Nick Piggin &lt;npiggin@suse.de&gt;
Acked-by: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Acked-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Acked-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>jbd: don't abort if flushing file data failed</title>
<updated>2008-07-25T17:53:32+00:00</updated>
<author>
<name>Hidehiro Kawai</name>
<email>hidehiro.kawai.ez@hitachi.com</email>
</author>
<published>2008-07-25T08:46:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cbe5f466f6995e10a10c7ae66d6dc8608f08a6b8'/>
<id>cbe5f466f6995e10a10c7ae66d6dc8608f08a6b8</id>
<content type='text'>
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 &lt;hidehiro.kawai.ez@hitachi.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&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>
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 &lt;hidehiro.kawai.ez@hitachi.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&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>
<entry>
<title>jbd: positively dispose the unmapped data buffers in journal_commit_transaction()</title>
<updated>2008-07-25T17:53:32+00:00</updated>
<author>
<name>Toshiyuki Okajima</name>
<email>toshi.okajima@jp.fujitsu.com</email>
</author>
<published>2008-07-25T08:46:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fc80c44277b3c92d808b73e9d40e120229aa4b6a'/>
<id>fc80c44277b3c92d808b73e9d40e120229aa4b6a</id>
<content type='text'>
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.

&lt;&lt;Excerpt of code at 'JBD: commit phase 7'&gt;&gt;
 &gt;         spin_lock(&amp;journal-&gt;j_list_lock);
 &gt;         while (commit_transaction-&gt;t_forget) {
 &gt;                 transaction_t *cp_transaction;
 &gt;                 struct buffer_head *bh;
 &gt;
 &gt;                 jh = commit_transaction-&gt;t_forget;
 &gt;...
 &gt;                 if (buffer_freed(bh)) {
 &gt;                 ^^^^^^^^^^^^^^^^^^^^^^^^
 &gt;                         clear_buffer_freed(bh);
 &gt;                        ^^^^^^^^^^^^^^^^^^^^^^^^
 &gt;                         clear_buffer_jbddirty(bh);
 &gt;                 }
 &gt;
 &gt;                 if (buffer_jbddirty(bh)) {
 &gt;                         JBUFFER_TRACE(jh, "add to new checkpointing trans");
 &gt;                         __journal_insert_checkpoint(jh, commit_transaction);
 &gt;                         JBUFFER_TRACE(jh, "refile for checkpoint writeback");
 &gt;                         __journal_refile_buffer(jh);
 &gt;                         jbd_unlock_bh_state(bh);
 &gt;                 } else {
 &gt;                         J_ASSERT_BH(bh, !buffer_dirty(bh));
 &gt; ...
 &gt;                         JBUFFER_TRACE(jh, "refile or unfile freed buffer");
 &gt;                         __journal_refile_buffer(jh);
 &gt;                         if (!jh-&gt;b_transaction) {
 &gt;                                 jbd_unlock_bh_state(bh);
 &gt;                                  /* needs a brelse */
 &gt;                                 journal_remove_journal_head(bh);
 &gt;                                 release_buffer_page(bh);
 &gt;                                 ^^^^^^^^^^^^^^^^^^^^^^^^
 &gt;                         } else
 &gt;                 }
****************************************************************
* 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 &lt;toshi.okajima@jp.fujitsu.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&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;
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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.

&lt;&lt;Excerpt of code at 'JBD: commit phase 7'&gt;&gt;
 &gt;         spin_lock(&amp;journal-&gt;j_list_lock);
 &gt;         while (commit_transaction-&gt;t_forget) {
 &gt;                 transaction_t *cp_transaction;
 &gt;                 struct buffer_head *bh;
 &gt;
 &gt;                 jh = commit_transaction-&gt;t_forget;
 &gt;...
 &gt;                 if (buffer_freed(bh)) {
 &gt;                 ^^^^^^^^^^^^^^^^^^^^^^^^
 &gt;                         clear_buffer_freed(bh);
 &gt;                        ^^^^^^^^^^^^^^^^^^^^^^^^
 &gt;                         clear_buffer_jbddirty(bh);
 &gt;                 }
 &gt;
 &gt;                 if (buffer_jbddirty(bh)) {
 &gt;                         JBUFFER_TRACE(jh, "add to new checkpointing trans");
 &gt;                         __journal_insert_checkpoint(jh, commit_transaction);
 &gt;                         JBUFFER_TRACE(jh, "refile for checkpoint writeback");
 &gt;                         __journal_refile_buffer(jh);
 &gt;                         jbd_unlock_bh_state(bh);
 &gt;                 } else {
 &gt;                         J_ASSERT_BH(bh, !buffer_dirty(bh));
 &gt; ...
 &gt;                         JBUFFER_TRACE(jh, "refile or unfile freed buffer");
 &gt;                         __journal_refile_buffer(jh);
 &gt;                         if (!jh-&gt;b_transaction) {
 &gt;                                 jbd_unlock_bh_state(bh);
 &gt;                                  /* needs a brelse */
 &gt;                                 journal_remove_journal_head(bh);
 &gt;                                 release_buffer_page(bh);
 &gt;                                 ^^^^^^^^^^^^^^^^^^^^^^^^
 &gt;                         } else
 &gt;                 }
****************************************************************
* 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 &lt;toshi.okajima@jp.fujitsu.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&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;
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