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<title>linux/fs/ext2, branch v2.6.28.3</title>
<subtitle>Linux kernel source tree</subtitle>
<id>https://git.amat.us/linux/atom/fs/ext2?h=v2.6.28.3</id>
<link rel='self' href='https://git.amat.us/linux/atom/fs/ext2?h=v2.6.28.3'/>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/'/>
<updated>2008-10-23T17:23:07Z</updated>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev</title>
<updated>2008-10-23T17:23:07Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2008-10-23T17:23:07Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=22484856402bfa1ff3defe47f6029ab0418240d9'/>
<id>urn:sha1:22484856402bfa1ff3defe47f6029ab0418240d9</id>
<content type='text'>
* git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev: (66 commits)
  [PATCH] kill the rest of struct file propagation in block ioctls
  [PATCH] get rid of struct file use in blkdev_ioctl() BLKBSZSET
  [PATCH] get rid of blkdev_locked_ioctl()
  [PATCH] get rid of blkdev_driver_ioctl()
  [PATCH] sanitize blkdev_get() and friends
  [PATCH] remember mode of reiserfs journal
  [PATCH] propagate mode through swsusp_close()
  [PATCH] propagate mode through open_bdev_excl/close_bdev_excl
  [PATCH] pass fmode_t to blkdev_put()
  [PATCH] kill the unused bsize on the send side of /dev/loop
  [PATCH] trim file propagation in block/compat_ioctl.c
  [PATCH] end of methods switch: remove the old ones
  [PATCH] switch sr
  [PATCH] switch sd
  [PATCH] switch ide-scsi
  [PATCH] switch tape_block
  [PATCH] switch dcssblk
  [PATCH] switch dasd
  [PATCH] switch mtd_blkdevs
  [PATCH] switch mmc
  ...
</content>
</entry>
<entry>
<title>[PATCH] get rid of on-stack dentry in ext2_get_parent()</title>
<updated>2008-10-23T09:13:09Z</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2008-08-24T11:28:39Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=a9885444f7ff6e9156adb1adf5558ded9a39ad0a'/>
<id>urn:sha1:a9885444f7ff6e9156adb1adf5558ded9a39ad0a</id>
<content type='text'>
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>[PATCH] switch all filesystems over to d_obtain_alias</title>
<updated>2008-10-23T09:13:01Z</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2008-08-11T13:49:04Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=440037287c5ebb07033ab927ca16bb68c291d309'/>
<id>urn:sha1:440037287c5ebb07033ab927ca16bb68c291d309</id>
<content type='text'>
Switch all users of d_alloc_anon to d_obtain_alias.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>[PATCH] move block_device_operations to blkdev.h</title>
<updated>2008-10-21T11:47:20Z</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2007-10-08T17:26:20Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=08f85851215100d0eebf026810955ee6ad456c38'/>
<id>urn:sha1:08f85851215100d0eebf026810955ee6ad456c38</id>
<content type='text'>
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>fs/Kconfig: move ext2, ext3, ext4, JBD, JBD2 out</title>
<updated>2008-10-20T18:43:59Z</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2008-10-20T18:28:45Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=6da0b38f4433fb0f24615449d7966471b6e5eae0'/>
<id>urn:sha1:6da0b38f4433fb0f24615449d7966471b6e5eae0</id>
<content type='text'>
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 &lt;adobriyan@gmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>ext2: avoid printk floods in the face of directory corruption</title>
<updated>2008-10-16T18:21:46Z</updated>
<author>
<name>Eric Sandeen</name>
<email>sandeen@redhat.com</email>
</author>
<published>2008-10-16T05:04:02Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=bd39597cbd42a784105a04010100e27267481c67'/>
<id>urn:sha1:bd39597cbd42a784105a04010100e27267481c67</id>
<content type='text'>
A very large directory with many read failures (either due to storage
problems, or due to invalid size &amp; blocks from corruption) will generate a
printk storm as the filesystem continues to try to read all the blocks.
This flood of messages can tie up the box until it is complete - which may
be a very long time, especially for very large corrupted values.

This is fixed by only reporting the corruption once each time we try to
read the directory.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Eric Sandeen &lt;sandeen@redhat.com&gt;
Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: Eugene Teo &lt;eugeneteo@kernel.sg&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>ext2: fix ext2 block reservation early ENOSPC issue</title>
<updated>2008-10-16T18:21:45Z</updated>
<author>
<name>Mingming Cao</name>
<email>cmm@us.ibm.com</email>
</author>
<published>2008-10-16T05:04:01Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=d707d31c972b657dfc2efefd0b99cc4e14223dab'/>
<id>urn:sha1:d707d31c972b657dfc2efefd0b99cc4e14223dab</id>
<content type='text'>
We could run into ENOSPC error on ext2, even when there is free blocks on
the filesystem.

The problem is triggered in the case the goal block group has 0 free
blocks , and the rest block groups are skipped due to the check of
"free_blocks &lt; windowsz/2".  Current code could fall back to non
reservation allocation to prevent early ENOSPC after examing all the block
groups with reservation on , but this code was bypassed if the reservation
window is turned off already, which is true in this case.

This patch fixed two issues:
1) We don't need to turn off block reservation if the goal block group has
0 free blocks left and continue search for the rest of block groups.

Current code the intention is to turn off the block reservation if the
goal allocation group has a few (some) free blocks left (not enough for
make the desired reservation window),to try to allocation in the goal
block group, to get better locality.  But if the goal blocks have 0 free
blocks, it should leave the block reservation on, and continues search for
the next block groups,rather than turn off block reservation completely.

2) we don't need to check the window size if the block reservation is off.

The problem was originally found and fixed in ext4.

Signed-off-by: Mingming Cao &lt;cmm@us.ibm.com&gt;
Cc: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>vfs: Use const for kernel parser table</title>
<updated>2008-10-13T17:10:37Z</updated>
<author>
<name>Steven Whitehouse</name>
<email>swhiteho@redhat.com</email>
</author>
<published>2008-10-13T09:46:57Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=a447c0932445f92ce6f4c1bd020f62c5097a7842'/>
<id>urn:sha1:a447c0932445f92ce6f4c1bd020f62c5097a7842</id>
<content type='text'>
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.

This was posted for review some time ago and I believe its been in -mm
since then.

Signed-off-by: Steven Whitehouse &lt;swhiteho@redhat.com&gt;
Cc: Alexander Viro &lt;aviro@redhat.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>generic block based fiemap implementation</title>
<updated>2008-10-03T21:32:43Z</updated>
<author>
<name>Josef Bacik</name>
<email>jbacik@redhat.com</email>
</author>
<published>2008-10-03T21:32:43Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=68c9d702bb72f367f3b148963ec6cf5e07ff7f65'/>
<id>urn:sha1:68c9d702bb72f367f3b148963ec6cf5e07ff7f65</id>
<content type='text'>
Any block based fs (this patch includes ext3) just has to declare its own
fiemap() function and then call this generic function with its own
get_block_t. This works well for block based filesystems that will map
multiple contiguous blocks at one time, but will work for filesystems that
only map one block at a time, you will just end up with an "extent" for each
block. One gotcha is this will not play nicely where there is hole+data
after the EOF. This function will assume its hit the end of the data as soon
as it hits a hole after the EOF, so if there is any data past that it will
not pick that up. AFAIK no block based fs does this anyway, but its in the
comments of the function anyway just in case.

Signed-off-by: Josef Bacik &lt;jbacik@redhat.com&gt;
Signed-off-by: Mark Fasheh &lt;mfasheh@suse.com&gt;
Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: linux-fsdevel@vger.kernel.org
</content>
</entry>
<entry>
<title>vfs: pagecache usage optimization for pagesize!=blocksize</title>
<updated>2008-07-28T23:30:21Z</updated>
<author>
<name>Hisashi Hifumi</name>
<email>hifumi.hisashi@oss.ntt.co.jp</email>
</author>
<published>2008-07-28T22:46:36Z</published>
<link rel='alternate' type='text/html' href='https://git.amat.us/linux/commit/?id=8ab22b9abb5c55413802e4adc9aa6223324547c3'/>
<id>urn:sha1:8ab22b9abb5c55413802e4adc9aa6223324547c3</id>
<content type='text'>
When we read some part of a file through pagecache, if there is a
pagecache of corresponding index but this page is not uptodate, read IO
is issued and this page will be uptodate.

I think this is good for pagesize == blocksize environment but there is
room for improvement on pagesize != blocksize environment.  Because in
this case a page can have multiple buffers and even if a page is not
uptodate, some buffers can be uptodate.

So I suggest that when all buffers which correspond to a part of a file
that we want to read are uptodate, use this pagecache and copy data from
this pagecache to user buffer even if a page is not uptodate.  This can
reduce read IO and improve system throughput.

I wrote a benchmark program and got result number with this program.

This benchmark do:

  1: mount and open a test file.

  2: create a 512MB file.

  3: close a file and umount.

  4: mount and again open a test file.

  5: pwrite randomly 300000 times on a test file.  offset is aligned
     by IO size(1024bytes).

  6: measure time of preading randomly 100000 times on a test file.

The result was:
	2.6.26
        330 sec

	2.6.26-patched
        226 sec

Arch:i386
Filesystem:ext3
Blocksize:1024 bytes
Memory: 1GB

On ext3/4, a file is written through buffer/block.  So random read/write
mixed workloads or random read after random write workloads are optimized
with this patch under pagesize != blocksize environment.  This test result
showed this.

The benchmark program is as follows:

#include &lt;stdio.h&gt;
#include &lt;sys/types.h&gt;
#include &lt;sys/stat.h&gt;
#include &lt;fcntl.h&gt;
#include &lt;unistd.h&gt;
#include &lt;time.h&gt;
#include &lt;stdlib.h&gt;
#include &lt;string.h&gt;
#include &lt;sys/mount.h&gt;

#define LEN 1024
#define LOOP 1024*512 /* 512MB */

main(void)
{
	unsigned long i, offset, filesize;
	int fd;
	char buf[LEN];
	time_t t1, t2;

	if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) &lt; 0) {
		perror("cannot mount\n");
		exit(1);
	}
	memset(buf, 0, LEN);
	fd = open("/root/test1/testfile", O_CREAT|O_RDWR|O_TRUNC);
	if (fd &lt; 0) {
		perror("cannot open file\n");
		exit(1);
	}
	for (i = 0; i &lt; LOOP; i++)
		write(fd, buf, LEN);
	close(fd);
	if (umount("/root/test1/") &lt; 0) {
		perror("cannot umount\n");
		exit(1);
	}
	if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) &lt; 0) {
		perror("cannot mount\n");
		exit(1);
	}
	fd = open("/root/test1/testfile", O_RDWR);
	if (fd &lt; 0) {
		perror("cannot open file\n");
		exit(1);
	}

	filesize = LEN * LOOP;
	for (i = 0; i &lt; 300000; i++){
		offset = (random() % filesize) &amp; (~(LEN - 1));
		pwrite(fd, buf, LEN, offset);
	}
	printf("start test\n");
	time(&amp;t1);
	for (i = 0; i &lt; 100000; i++){
		offset = (random() % filesize) &amp; (~(LEN - 1));
		pread(fd, buf, LEN, offset);
	}
	time(&amp;t2);
	printf("%ld sec\n", t2-t1);
	close(fd);
	if (umount("/root/test1/") &lt; 0) {
		perror("cannot umount\n");
		exit(1);
	}
}

Signed-off-by: Hisashi Hifumi &lt;hifumi.hisashi@oss.ntt.co.jp&gt;
Cc: Nick Piggin &lt;nickpiggin@yahoo.com.au&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Jan Kara &lt;jack@ucw.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>
</entry>
</feed>
