<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/fs/qnx6, branch v4.9.28</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>more trivial -&gt;iterate_shared conversions</title>
<updated>2016-05-09T15:41:14+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2016-05-01T02:37:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c51da20c48b76ef1114d14b6b6ff190e11afab0e'/>
<id>c51da20c48b76ef1114d14b6b6ff190e11afab0e</id>
<content type='text'>
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros</title>
<updated>2016-04-04T17:41:08+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2016-04-01T12:29:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=09cbfeaf1a5a67bfb3201e0c83c810cecb2efa5a'/>
<id>09cbfeaf1a5a67bfb3201e0c83c810cecb2efa5a</id>
<content type='text'>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - &lt;foo&gt; &lt;&lt; (PAGE_CACHE_SHIFT - PAGE_SHIFT) -&gt; &lt;foo&gt;;

 - &lt;foo&gt; &gt;&gt; (PAGE_CACHE_SHIFT - PAGE_SHIFT) -&gt; &lt;foo&gt;;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -&gt; PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -&gt; get_page();

 - page_cache_release() -&gt; put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E &lt;&lt; (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E &gt;&gt; (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&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>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - &lt;foo&gt; &lt;&lt; (PAGE_CACHE_SHIFT - PAGE_SHIFT) -&gt; &lt;foo&gt;;

 - &lt;foo&gt; &gt;&gt; (PAGE_CACHE_SHIFT - PAGE_SHIFT) -&gt; &lt;foo&gt;;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -&gt; PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -&gt; get_page();

 - page_cache_release() -&gt; put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E &lt;&lt; (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E &gt;&gt; (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kmemcg: account certain kmem allocations to memcg</title>
<updated>2016-01-15T00:00:49+00:00</updated>
<author>
<name>Vladimir Davydov</name>
<email>vdavydov@virtuozzo.com</email>
</author>
<published>2016-01-14T23:18:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5d097056c9a017a3b720849efb5432f37acabbac'/>
<id>5d097056c9a017a3b720849efb5432f37acabbac</id>
<content type='text'>
Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable-&gt;full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Greg Thelen &lt;gthelen@google.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.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>
Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable-&gt;full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Greg Thelen &lt;gthelen@google.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.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>don't put symlink bodies in pagecache into highmem</title>
<updated>2015-12-09T03:41:36+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2015-11-17T06:07:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=21fc61c73c3903c4c312d0802da01ec2b323d174'/>
<id>21fc61c73c3903c4c312d0802da01ec2b323d174</id>
<content type='text'>
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.

new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases.  page_follow_link_light()
instrumented to yell about anything missed.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.

new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases.  page_follow_link_light()
instrumented to yell about anything missed.

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>pagemap.h: move dir_pages() over there</title>
<updated>2015-06-23T22:02:00+00:00</updated>
<author>
<name>Fabian Frederick</name>
<email>fabf@skynet.be</email>
</author>
<published>2015-05-24T15:19:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b57c2cb9ea1a02c2ae08e16de8c20cc13ffbf85a'/>
<id>b57c2cb9ea1a02c2ae08e16de8c20cc13ffbf85a</id>
<content type='text'>
That function was declared in a lot of filesystems to calculate
directory pages.

Signed-off-by: Fabian Frederick &lt;fabf@skynet.be&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
That function was declared in a lot of filesystems to calculate
directory pages.

Signed-off-by: Fabian Frederick &lt;fabf@skynet.be&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>VFS: normal filesystems (and lustre): d_inode() annotations</title>
<updated>2015-04-15T19:06:57+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2015-03-17T22:25:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2b0143b5c986be1ce8408b3aadc4709e0a94429d'/>
<id>2b0143b5c986be1ce8408b3aadc4709e0a94429d</id>
<content type='text'>
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs/qnx6: update debugging to current functions</title>
<updated>2014-08-08T22:57:26+00:00</updated>
<author>
<name>Fabian Frederick</name>
<email>fabf@skynet.be</email>
</author>
<published>2014-08-08T21:23:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fa5a7a41a601d952e53bfcfa6d50ca22b956ee3a'/>
<id>fa5a7a41a601d952e53bfcfa6d50ca22b956ee3a</id>
<content type='text'>
Add DDEBUG in Makefile when CONFIG_QNX6FS_DEBUG is set.  All QNX6DEBUG
messages are replaced by pr_debug which means debugging will be emitted in
debug level only and no more in error and info levels.  debug uses now
pr_fmt and __func__

QNX6DEBUG definition has been removed.

Signed-off-by: Fabian Frederick &lt;fabf@skynet.be&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Kai Bankett &lt;chaosman@ontika.net&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&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>
Add DDEBUG in Makefile when CONFIG_QNX6FS_DEBUG is set.  All QNX6DEBUG
messages are replaced by pr_debug which means debugging will be emitted in
debug level only and no more in error and info levels.  debug uses now
pr_fmt and __func__

QNX6DEBUG definition has been removed.

Signed-off-by: Fabian Frederick &lt;fabf@skynet.be&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Kai Bankett &lt;chaosman@ontika.net&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&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>fs/qnx6: use pr_fmt and __func__ in logging</title>
<updated>2014-08-08T22:57:26+00:00</updated>
<author>
<name>Fabian Frederick</name>
<email>fabf@skynet.be</email>
</author>
<published>2014-08-08T21:23:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e6c3261653a22f7481791e02fe19d11faac214fb'/>
<id>e6c3261653a22f7481791e02fe19d11faac214fb</id>
<content type='text'>
Remove "qnx6:" and "qnx6: " from each logging instruction.

Signed-off-by: Fabian Frederick &lt;fabf@skynet.be&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Kai Bankett &lt;chaosman@ontika.net&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&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 "qnx6:" and "qnx6: " from each logging instruction.

Signed-off-by: Fabian Frederick &lt;fabf@skynet.be&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Kai Bankett &lt;chaosman@ontika.net&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&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>fs/qnx6: convert printk to pr_foo()</title>
<updated>2014-08-08T22:57:25+00:00</updated>
<author>
<name>Fabian Frederick</name>
<email>fabf@skynet.be</email>
</author>
<published>2014-08-08T21:23:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e00d5b5ad70c6c4fb978fe843c0bbb3294d63223'/>
<id>e00d5b5ad70c6c4fb978fe843c0bbb3294d63223</id>
<content type='text'>
Use current logging functions.

Coalesce formats.

Signed-off-by: Fabian Frederick &lt;fabf@skynet.be&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Kai Bankett &lt;chaosman@ontika.net&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&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>
Use current logging functions.

Coalesce formats.

Signed-off-by: Fabian Frederick &lt;fabf@skynet.be&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Kai Bankett &lt;chaosman@ontika.net&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&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>fs: push sync_filesystem() down to the file system's remount_fs()</title>
<updated>2014-03-13T14:14:33+00:00</updated>
<author>
<name>Theodore Ts'o</name>
<email>tytso@mit.edu</email>
</author>
<published>2014-03-13T14:14:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=02b9984d640873b7b3809e63f81a0d7e13496886'/>
<id>02b9984d640873b7b3809e63f81a0d7e13496886</id>
<content type='text'>
Previously, the no-op "mount -o mount /dev/xxx" operation when the
file system is already mounted read-write causes an implied,
unconditional syncfs().  This seems pretty stupid, and it's certainly
documented or guaraunteed to do this, nor is it particularly useful,
except in the case where the file system was mounted rw and is getting
remounted read-only.

However, it's possible that there might be some file systems that are
actually depending on this behavior.  In most file systems, it's
probably fine to only call sync_filesystem() when transitioning from
read-write to read-only, and there are some file systems where this is
not needed at all (for example, for a pseudo-filesystem or something
like romfs).

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Artem Bityutskiy &lt;dedekind1@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Evgeniy Dushistov &lt;dushistov@mail.ru&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: OGAWA Hirofumi &lt;hirofumi@mail.parknet.co.jp&gt;
Cc: Anders Larsen &lt;al@alarsen.net&gt;
Cc: Phillip Lougher &lt;phillip@squashfs.org.uk&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Mikulas Patocka &lt;mikulas@artax.karlin.mff.cuni.cz&gt;
Cc: Petr Vandrovec &lt;petr@vandrovec.name&gt;
Cc: xfs@oss.sgi.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: fuse-devel@lists.sourceforge.net
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: linux-nilfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: reiserfs-devel@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Previously, the no-op "mount -o mount /dev/xxx" operation when the
file system is already mounted read-write causes an implied,
unconditional syncfs().  This seems pretty stupid, and it's certainly
documented or guaraunteed to do this, nor is it particularly useful,
except in the case where the file system was mounted rw and is getting
remounted read-only.

However, it's possible that there might be some file systems that are
actually depending on this behavior.  In most file systems, it's
probably fine to only call sync_filesystem() when transitioning from
read-write to read-only, and there are some file systems where this is
not needed at all (for example, for a pseudo-filesystem or something
like romfs).

Signed-off-by: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Artem Bityutskiy &lt;dedekind1@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Evgeniy Dushistov &lt;dushistov@mail.ru&gt;
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: OGAWA Hirofumi &lt;hirofumi@mail.parknet.co.jp&gt;
Cc: Anders Larsen &lt;al@alarsen.net&gt;
Cc: Phillip Lougher &lt;phillip@squashfs.org.uk&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Mikulas Patocka &lt;mikulas@artax.karlin.mff.cuni.cz&gt;
Cc: Petr Vandrovec &lt;petr@vandrovec.name&gt;
Cc: xfs@oss.sgi.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: fuse-devel@lists.sourceforge.net
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: linux-nilfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: reiserfs-devel@vger.kernel.org
</pre>
</div>
</content>
</entry>
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