<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/fs/f2fs/data.c, branch v3.8</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>f2fs: support swapfile</title>
<updated>2013-01-22T01:48:58+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk.kim@samsung.com</email>
</author>
<published>2013-01-17T11:30:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c01e54b770e69c65525295eb2668be3dc0822406'/>
<id>c01e54b770e69c65525295eb2668be3dc0822406</id>
<content type='text'>
This patch adds f2fs_bmap operation to the data address space.
This enables f2fs to support swapfile.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch adds f2fs_bmap operation to the data address space.
This enables f2fs to support swapfile.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: remove the blk_plug usage in f2fs_write_data_pages</title>
<updated>2013-01-15T11:18:16+00:00</updated>
<author>
<name>Namjae Jeon</name>
<email>namjae.jeon@samsung.com</email>
</author>
<published>2013-01-15T07:45:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fa9150a84ca333f68127097c4fa1eda4b3913a22'/>
<id>fa9150a84ca333f68127097c4fa1eda4b3913a22</id>
<content type='text'>
Let's consider the usage of blk_plug in f2fs_write_data_pages().
We can come up with the two issues: lock contention and task awareness.

1. Merging bios prior to grabing "queue lock"
 The f2fs merges consecutive IOs in the file system level before
 submitting any bios, which is similar with the back merge by the
 plugging mechanism in attempt_plug_merge(). Both of them need to acquire
 no queue lock.

2. Merging policy with respect to tasks
 The f2fs merges IOs as much as possible regardless of tasks, while
 blk-plugging is conducted on a basis of tasks. As we can understand
 there are trade-offs, f2fs tries to maximize the write performance with
 well-merged bios.

As a result, if f2fs produces many consecutive but separated bios in
writepages(), it would be good to use blk-plugging since f2fs would be
able to avoid queue lock contention in the block layer by merging them.
But, f2fs merges IOs and submit one bio, which means that there are not
much chances to merge bios by attempt_plug_merge().

However, f2fs has already been used blk_plug by triggering generic_writepages()
in f2fs_write_data_pages().
So to make the overall code consistency, I'd like to remove blk_plug there.

Signed-off-by: Namjae Jeon &lt;namjae.jeon@samsung.com&gt;
Signed-off-by: Amit Sahrawat &lt;a.sahrawat@samsung.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Let's consider the usage of blk_plug in f2fs_write_data_pages().
We can come up with the two issues: lock contention and task awareness.

1. Merging bios prior to grabing "queue lock"
 The f2fs merges consecutive IOs in the file system level before
 submitting any bios, which is similar with the back merge by the
 plugging mechanism in attempt_plug_merge(). Both of them need to acquire
 no queue lock.

2. Merging policy with respect to tasks
 The f2fs merges IOs as much as possible regardless of tasks, while
 blk-plugging is conducted on a basis of tasks. As we can understand
 there are trade-offs, f2fs tries to maximize the write performance with
 well-merged bios.

As a result, if f2fs produces many consecutive but separated bios in
writepages(), it would be good to use blk-plugging since f2fs would be
able to avoid queue lock contention in the block layer by merging them.
But, f2fs merges IOs and submit one bio, which means that there are not
much chances to merge bios by attempt_plug_merge().

However, f2fs has already been used blk_plug by triggering generic_writepages()
in f2fs_write_data_pages().
So to make the overall code consistency, I'd like to remove blk_plug there.

Signed-off-by: Namjae Jeon &lt;namjae.jeon@samsung.com&gt;
Signed-off-by: Amit Sahrawat &lt;a.sahrawat@samsung.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: add missing #include &lt;linux/prefetch.h&gt;</title>
<updated>2012-12-28T02:22:43+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert@linux-m68k.org</email>
</author>
<published>2012-12-19T21:19:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=690e4a3ead5f88fc95f7650816d1376aa2e79db5'/>
<id>690e4a3ead5f88fc95f7650816d1376aa2e79db5</id>
<content type='text'>
m68k allmodconfig:

fs/f2fs/data.c: In function ‘read_end_io’:
fs/f2fs/data.c:311: error: implicit declaration of function ‘prefetchw’

fs/f2fs/segment.c: In function ‘f2fs_end_io_write’:
fs/f2fs/segment.c:628: error: implicit declaration of function ‘prefetchw’

Signed-off-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
m68k allmodconfig:

fs/f2fs/data.c: In function ‘read_end_io’:
fs/f2fs/data.c:311: error: implicit declaration of function ‘prefetchw’

fs/f2fs/segment.c: In function ‘f2fs_end_io_write’:
fs/f2fs/segment.c:628: error: implicit declaration of function ‘prefetchw’

Signed-off-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: cleanup the f2fs_bio_alloc routine</title>
<updated>2012-12-11T04:43:45+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk.kim@samsung.com</email>
</author>
<published>2012-12-10T00:26:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3cd8a23948b29301f8f67b8d70c5c18fabbc05e1'/>
<id>3cd8a23948b29301f8f67b8d70c5c18fabbc05e1</id>
<content type='text'>
Do cleanup more for better code readability.

- Change the parameter set of f2fs_bio_alloc()
  This function should allocate a bio only since it is not something like
  f2fs_bio_init(). Instead, the caller should initialize the allocated bio.

- Introduce SECTOR_FROM_BLOCK
  This macro translates a block address to its sector address.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
Reviewed-by: Namjae Jeon &lt;namjae.jeon@samsung.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Do cleanup more for better code readability.

- Change the parameter set of f2fs_bio_alloc()
  This function should allocate a bio only since it is not something like
  f2fs_bio_init(). Instead, the caller should initialize the allocated bio.

- Introduce SECTOR_FROM_BLOCK
  This macro translates a block address to its sector address.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
Reviewed-by: Namjae Jeon &lt;namjae.jeon@samsung.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: adjust kernel coding style</title>
<updated>2012-12-11T04:43:42+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk.kim@samsung.com</email>
</author>
<published>2012-11-29T04:28:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0a8165d7c2cf1395059db20ab07665baf3758fcd'/>
<id>0a8165d7c2cf1395059db20ab07665baf3758fcd</id>
<content type='text'>
As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix endian conversion bugs reported by sparse</title>
<updated>2012-12-11T04:43:42+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk.kim@samsung.com</email>
</author>
<published>2012-11-28T07:12:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=25ca923b2a766b9c93b63777ead351137533a623'/>
<id>25ca923b2a766b9c93b63777ead351137533a623</id>
<content type='text'>
This patch should resolve the bugs reported by the sparse tool.
Initial reports were written by "kbuild test robot" managed by fengguang.wu.

In my local machines, I've tested also by running:
&gt; make C=2 CF="-D__CHECK_ENDIAN__"

Accordingly, I've found lots of warnings and bugs related to the endian
conversion. And I've fixed all at this moment.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch should resolve the bugs reported by the sparse tool.
Initial reports were written by "kbuild test robot" managed by fengguang.wu.

In my local machines, I've tested also by running:
&gt; make C=2 CF="-D__CHECK_ENDIAN__"

Accordingly, I've found lots of warnings and bugs related to the endian
conversion. And I've fixed all at this moment.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: add address space operations for data</title>
<updated>2012-12-11T04:43:41+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk.kim@samsung.com</email>
</author>
<published>2012-11-02T08:10:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eb47b8009dc969a3386c983bd5e798e9f690c5d9'/>
<id>eb47b8009dc969a3386c983bd5e798e9f690c5d9</id>
<content type='text'>
This adds address space operations for data.

- F2FS supports readpages(), writepages(), and direct_IO().

- Because of out-of-place writes, f2fs_direct_IO() does not write data in place.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This adds address space operations for data.

- F2FS supports readpages(), writepages(), and direct_IO().

- Because of out-of-place writes, f2fs_direct_IO() does not write data in place.

Signed-off-by: Jaegeuk Kim &lt;jaegeuk.kim@samsung.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
