<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/fs/ext4/ialloc.c, branch v3.10.61</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>ext4: fix oops when loading block bitmap failed</title>
<updated>2014-11-14T16:47:58+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2014-10-30T14:53:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6ce75ebb5334c12febaf520682926ce34c3cfe2b'/>
<id>6ce75ebb5334c12febaf520682926ce34c3cfe2b</id>
<content type='text'>
commit 599a9b77ab289d85c2d5c8607624efbe1f552b0f upstream.

When we fail to load block bitmap in __ext4_new_inode() we will
dereference NULL pointer in ext4_journal_get_write_access(). So check
for error from ext4_read_block_bitmap().

Coverity-id: 989065
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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<pre>
commit 599a9b77ab289d85c2d5c8607624efbe1f552b0f upstream.

When we fail to load block bitmap in __ext4_new_inode() we will
dereference NULL pointer in ext4_journal_get_write_access(). So check
for error from ext4_read_block_bitmap().

Coverity-id: 989065
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: fix unjournalled bg descriptor while initializing inode bitmap</title>
<updated>2014-07-17T22:58:02+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2014-07-05T20:28:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7cefa2c68d1994a68c450c7de58115eae3a82b1d'/>
<id>7cefa2c68d1994a68c450c7de58115eae3a82b1d</id>
<content type='text'>
commit 61c219f5814277ecb71d64cb30297028d6665979 upstream.

The first time that we allocate from an uninitialized inode allocation
bitmap, if the block allocation bitmap is also uninitalized, we need
to get write access to the block group descriptor before we start
modifying the block group descriptor flags and updating the free block
count, etc.  Otherwise, there is the potential of a bad journal
checksum (if journal checksums are enabled), and of the file system
becoming inconsistent if we crash at exactly the wrong time.

Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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<pre>
commit 61c219f5814277ecb71d64cb30297028d6665979 upstream.

The first time that we allocate from an uninitialized inode allocation
bitmap, if the block allocation bitmap is also uninitalized, we need
to get write access to the block group descriptor before we start
modifying the block group descriptor flags and updating the free block
count, etc.  Otherwise, there is the potential of a bad journal
checksum (if journal checksums are enabled), and of the file system
becoming inconsistent if we crash at exactly the wrong time.

Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: make sure group number is bumped after a inode allocation race</title>
<updated>2013-08-15T05:59:05+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2013-07-26T19:15:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dc953e8985b02cf8952eca4214604f6bd20f1d86'/>
<id>dc953e8985b02cf8952eca4214604f6bd20f1d86</id>
<content type='text'>
commit a34eb503742fd25155fd6cff6163daacead9fbc3 upstream.

When we try to allocate an inode, and there is a race between two
CPU's trying to grab the same inode, _and_ this inode is the last free
inode in the block group, make sure the group number is bumped before
we continue searching the rest of the block groups.  Otherwise, we end
up searching the current block group twice, and we end up skipping
searching the last block group.  So in the unlikely situation where
almost all of the inodes are allocated, it's possible that we will
return ENOSPC even though there might be free inodes in that last
block group.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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<pre>
commit a34eb503742fd25155fd6cff6163daacead9fbc3 upstream.

When we try to allocate an inode, and there is a race between two
CPU's trying to grab the same inode, _and_ this inode is the last free
inode in the block group, make sure the group number is bumped before
we continue searching the rest of the block groups.  Otherwise, we end
up searching the current block group twice, and we end up skipping
searching the last block group.  So in the unlikely situation where
almost all of the inodes are allocated, it's possible that we will
return ENOSPC even though there might be free inodes in that last
block group.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: mark all metadata I/O with REQ_META</title>
<updated>2013-04-20T19:46:17+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2013-04-20T19:46:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9f203507ed277ee86e3f76a15e09db1c92e40b94'/>
<id>9f203507ed277ee86e3f76a15e09db1c92e40b94</id>
<content type='text'>
As Dave Chinner pointed out at the 2013 LSF/MM workshop, it's
important that metadata I/O requests are marked as such to avoid
priority inversions caused by I/O bandwidth throttling.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</content>
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<pre>
As Dave Chinner pointed out at the 2013 LSF/MM workshop, it's
important that metadata I/O requests are marked as such to avoid
priority inversions caused by I/O bandwidth throttling.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: move quota initialization out of inode allocation transaction</title>
<updated>2013-04-19T17:38:14+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2013-04-19T17:38:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=eb9cc7e16b32c898a1d715733c590f115aa0a099'/>
<id>eb9cc7e16b32c898a1d715733c590f115aa0a099</id>
<content type='text'>
Inode allocation transaction is pretty heavy (246 credits with quotas
and extents before previous patch, still around 200 after it).  This is
mostly due to credits required for allocation of quota structures
(credits there are heavily overestimated but it's difficult to make
better estimates if we don't want to wire non-trivial assumptions about
quota format into filesystem).

So move quota initialization out of allocation transaction. That way
transaction for quota structure allocation will be started only if we
need to look up quota structure on disk (rare) and furthermore it will
be started for each quota type separately, not for all of them at once.
This reduces maximum transaction size to 34 is most cases and to 73 in
the worst case.

[ Modified by tytso to clean up the cleanup paths for error handling.
  Also use a separate call to ext4_std_error() for each failure so it
  is easier for someone who is debugging a problem in this function to
  determine which function call failed. ]

Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</content>
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<pre>
Inode allocation transaction is pretty heavy (246 credits with quotas
and extents before previous patch, still around 200 after it).  This is
mostly due to credits required for allocation of quota structures
(credits there are heavily overestimated but it's difficult to make
better estimates if we don't want to wire non-trivial assumptions about
quota format into filesystem).

So move quota initialization out of allocation transaction. That way
transaction for quota structure allocation will be started only if we
need to look up quota structure on disk (rare) and furthermore it will
be started for each quota type separately, not for all of them at once.
This reduces maximum transaction size to 34 is most cases and to 73 in
the worst case.

[ Modified by tytso to clean up the cleanup paths for error handling.
  Also use a separate call to ext4_std_error() for each failure so it
  is easier for someone who is debugging a problem in this function to
  determine which function call failed. ]

Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: fix usless declarations</title>
<updated>2013-04-10T02:48:36+00:00</updated>
<author>
<name>Dmitri Monakho</name>
<email>dmonakhov@openvz.org</email>
</author>
<published>2013-04-10T02:48:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8c8e0ca622847a8b1b281b8927d62229effa0004'/>
<id>8c8e0ca622847a8b1b281b8927d62229effa0004</id>
<content type='text'>
This patch should fix sparse complains about shadow declatations.

Signed-off-by: Dmitry Monakhov &lt;dmonakhov@openvz.org&gt;
Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch should fix sparse complains about shadow declatations.

Signed-off-by: Dmitry Monakhov &lt;dmonakhov@openvz.org&gt;
Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: use atomic64_t for the per-flexbg free_clusters count</title>
<updated>2013-03-12T03:39:59+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2013-03-12T03:39:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=90ba983f6889e65a3b506b30dc606aa9d1d46cd2'/>
<id>90ba983f6889e65a3b506b30dc606aa9d1d46cd2</id>
<content type='text'>
A user who was using a 8TB+ file system and with a very large flexbg
size (&gt; 65536) could cause the atomic_t used in the struct flex_groups
to overflow.  This was detected by PaX security patchset:

http://forums.grsecurity.net/viewtopic.php?f=3&amp;t=3289&amp;p=12551#p12551

This bug was introduced in commit 9f24e4208f7e, so it's been around
since 2.6.30.  :-(

Fix this by using an atomic64_t for struct orlav_stats's
free_clusters.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Reviewed-by: Lukas Czerner &lt;lczerner@redhat.com&gt;
Cc: stable@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A user who was using a 8TB+ file system and with a very large flexbg
size (&gt; 65536) could cause the atomic_t used in the struct flex_groups
to overflow.  This was detected by PaX security patchset:

http://forums.grsecurity.net/viewtopic.php?f=3&amp;t=3289&amp;p=12551#p12551

This bug was introduced in commit 9f24e4208f7e, so it's been around
since 2.6.30.  :-(

Fix this by using an atomic64_t for struct orlav_stats's
free_clusters.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Reviewed-by: Lukas Czerner &lt;lczerner@redhat.com&gt;
Cc: stable@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: use KERN_WARNING for warning messages</title>
<updated>2013-02-14T20:11:41+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2013-02-14T20:11:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8de5c325b4ee7d5b23b95edd28b81c9a2a9f427f'/>
<id>8de5c325b4ee7d5b23b95edd28b81c9a2a9f427f</id>
<content type='text'>
Some messages printed related to a WARN_ON(1) were printed using
KERN_NOTICE.  Use KERN_WARNING or ext4_warning() instead so that
context related to the WARN_ON() is printed at the same printk warning
level (and log files, etc.)

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</content>
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<pre>
Some messages printed related to a WARN_ON(1) were printed using
KERN_NOTICE.  Use KERN_WARNING or ext4_warning() instead so that
context related to the WARN_ON() is printed at the same printk warning
level (and log files, etc.)

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: start handle at the last possible moment when creating inodes</title>
<updated>2013-02-09T21:27:09+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2013-02-09T21:27:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1139575a927010390c6b38e4215a6d741b056074'/>
<id>1139575a927010390c6b38e4215a6d741b056074</id>
<content type='text'>
In ext4_{create,mknod,mkdir,symlink}(), don't start the journal handle
until the inode has been succesfully allocated.  In order to do this,
we need to start the handle in the ext4_new_inode().  So create a new
variant of this function, ext4_new_inode_start_handle(), so the handle
can be created at the last possible minute, before we need to modify
the inode allocation bitmap block.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</content>
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<pre>
In ext4_{create,mknod,mkdir,symlink}(), don't start the journal handle
until the inode has been succesfully allocated.  In order to do this,
we need to start the handle in the ext4_new_inode().  So create a new
variant of this function, ext4_new_inode_start_handle(), so the handle
can be created at the last possible minute, before we need to modify
the inode allocation bitmap block.

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: pass context information to jbd2__journal_start()</title>
<updated>2013-02-09T02:59:22+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2013-02-09T02:59:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9924a92a8c217576bd2a2b1bbbb854462f1a00ae'/>
<id>9924a92a8c217576bd2a2b1bbbb854462f1a00ae</id>
<content type='text'>
So we can better understand what bits of ext4 are responsible for
long-running jbd2 handles, use jbd2__journal_start() so we can pass
context information for logging purposes.

The recommended way for finding the longer-running handles is:

   T=/sys/kernel/debug/tracing
   EVENT=$T/events/jbd2/jbd2_handle_stats
   echo "interval &gt; 5" &gt; $EVENT/filter
   echo 1 &gt; $EVENT/enable

   ./run-my-fs-benchmark

   cat $T/trace &gt; /tmp/problem-handles

This will list handles that were active for longer than 20ms.  Having
longer-running handles is bad, because a commit started at the wrong
time could stall for those 20+ milliseconds, which could delay an
fsync() or an O_SYNC operation.  Here is an example line from the
trace file describing a handle which lived on for 311 jiffies, or over
1.2 seconds:

postmark-2917  [000] ....   196.435786: jbd2_handle_stats: dev 254,32 
   tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
   dirtied_blocks 0

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
So we can better understand what bits of ext4 are responsible for
long-running jbd2 handles, use jbd2__journal_start() so we can pass
context information for logging purposes.

The recommended way for finding the longer-running handles is:

   T=/sys/kernel/debug/tracing
   EVENT=$T/events/jbd2/jbd2_handle_stats
   echo "interval &gt; 5" &gt; $EVENT/filter
   echo 1 &gt; $EVENT/enable

   ./run-my-fs-benchmark

   cat $T/trace &gt; /tmp/problem-handles

This will list handles that were active for longer than 20ms.  Having
longer-running handles is bad, because a commit started at the wrong
time could stall for those 20+ milliseconds, which could delay an
fsync() or an O_SYNC operation.  Here is an example line from the
trace file describing a handle which lived on for 311 jiffies, or over
1.2 seconds:

postmark-2917  [000] ....   196.435786: jbd2_handle_stats: dev 254,32 
   tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
   dirtied_blocks 0

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
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