<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/fs/proc/proc_net.c, branch v3.0.95</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>include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h</title>
<updated>2010-03-30T13:02:32+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2010-03-24T08:04:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5a0e3ad6af8660be21ca98a971cd00f331318c05'/>
<id>5a0e3ad6af8660be21ca98a971cd00f331318c05</id>
<content type='text'>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -&gt; slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -&gt; slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>proc: stop using BKL</title>
<updated>2009-01-05T09:27:44+00:00</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2008-10-27T19:48:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b4df2b92d8461444fac429c75ba6e125c63056bc'/>
<id>b4df2b92d8461444fac429c75ba6e125c63056bc</id>
<content type='text'>
There are four BKL users in proc: de_put(), proc_lookup_de(),
proc_readdir_de(), proc_root_readdir(),

1) de_put()
-----------
de_put() is classic atomic_dec_and_test() refcount wrapper -- no BKL
needed. BKL doesn't matter to possible refcount leak as well.

2) proc_lookup_de()
-------------------
Walking PDE list is protected by proc_subdir_lock(), proc_get_inode() is
potentially blocking, all callers of proc_lookup_de() eventually end up
from -&gt;lookup hooks which is protected by directory's -&gt;i_mutex -- BKL
doesn't protect anything.

3) proc_readdir_de()
--------------------
"." and ".." part doesn't need BKL, walking PDE list is under
proc_subdir_lock, calling filldir callback is potentially blocking
because it writes to luserspace. All proc_readdir_de() callers
eventually come from -&gt;readdir hook which is under directory's
-&gt;i_mutex -- BKL doesn't protect anything.

4) proc_root_readdir_de()
-------------------------
proc_root_readdir_de is -&gt;readdir hook, see (3).

Since readdir hooks doesn't use BKL anymore, switch to
generic_file_llseek, since it also takes directory's i_mutex.

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There are four BKL users in proc: de_put(), proc_lookup_de(),
proc_readdir_de(), proc_root_readdir(),

1) de_put()
-----------
de_put() is classic atomic_dec_and_test() refcount wrapper -- no BKL
needed. BKL doesn't matter to possible refcount leak as well.

2) proc_lookup_de()
-------------------
Walking PDE list is protected by proc_subdir_lock(), proc_get_inode() is
potentially blocking, all callers of proc_lookup_de() eventually end up
from -&gt;lookup hooks which is protected by directory's -&gt;i_mutex -- BKL
doesn't protect anything.

3) proc_readdir_de()
--------------------
"." and ".." part doesn't need BKL, walking PDE list is under
proc_subdir_lock, calling filldir callback is potentially blocking
because it writes to luserspace. All proc_readdir_de() callers
eventually come from -&gt;readdir hook which is under directory's
-&gt;i_mutex -- BKL doesn't protect anything.

4) proc_root_readdir_de()
-------------------------
proc_root_readdir_de is -&gt;readdir hook, see (3).

Since readdir hooks doesn't use BKL anymore, switch to
generic_file_llseek, since it also takes directory's i_mutex.

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netns: make get_proc_net() static</title>
<updated>2008-07-22T21:19:19+00:00</updated>
<author>
<name>Adrian Bunk</name>
<email>bunk@kernel.org</email>
</author>
<published>2008-07-22T21:19:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8086cd451f08f4c0f9693fc66d87754bbd18cfba'/>
<id>8086cd451f08f4c0f9693fc66d87754bbd18cfba</id>
<content type='text'>
get_proc_net() can now become static.

Signed-off-by: Adrian Bunk &lt;bunk@kernel.org&gt;
Acked-by: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
get_proc_net() can now become static.

Signed-off-by: Adrian Bunk &lt;bunk@kernel.org&gt;
Acked-by: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>proc: consolidate per-net single-release callers</title>
<updated>2008-07-18T11:07:44+00:00</updated>
<author>
<name>Pavel Emelyanov</name>
<email>xemul@openvz.org</email>
</author>
<published>2008-07-18T11:07:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b6fcbdb4f283f7ba67cec3cda6be23da8e959031'/>
<id>b6fcbdb4f283f7ba67cec3cda6be23da8e959031</id>
<content type='text'>
They are symmetrical to single_open ones :)

Signed-off-by: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
They are symmetrical to single_open ones :)

Signed-off-by: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>proc: consolidate per-net single_open callers</title>
<updated>2008-07-18T11:07:21+00:00</updated>
<author>
<name>Pavel Emelyanov</name>
<email>xemul@openvz.org</email>
</author>
<published>2008-07-18T11:07:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=de05c557b24c7dffc6d392e3db120cf11c9f6ae7'/>
<id>de05c557b24c7dffc6d392e3db120cf11c9f6ae7</id>
<content type='text'>
There are already 7 of them - time to kill some duplicate code.

Signed-off-by: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There are already 7 of them - time to kill some duplicate code.

Signed-off-by: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netns: assign PDE-&gt;data before gluing entry into /proc tree</title>
<updated>2008-05-02T11:12:41+00:00</updated>
<author>
<name>Denis V. Lunev</name>
<email>den@openvz.org</email>
</author>
<published>2008-05-02T11:12:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=78e92b99ec4eb73755abd4e357b0b211eadafd88'/>
<id>78e92b99ec4eb73755abd4e357b0b211eadafd88</id>
<content type='text'>
In this unfortunate case, proc_mkdir_mode wrapper can't be used anymore and
this is no way to reuse proc_create_data due to nlinks assignment. So,
copy the code from proc_mkdir and assign PDE-&gt;data at the appropriate
moment.

Signed-off-by: Denis V. Lunev &lt;den@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In this unfortunate case, proc_mkdir_mode wrapper can't be used anymore and
this is no way to reuse proc_create_data due to nlinks assignment. So,
copy the code from proc_mkdir and assign PDE-&gt;data at the appropriate
moment.

Signed-off-by: Denis V. Lunev &lt;den@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[NETNS]: Remove ifdef CONFIG_NET braces in fs/proc/proc_net.c.</title>
<updated>2008-04-02T07:10:04+00:00</updated>
<author>
<name>Denis V. Lunev</name>
<email>den@openvz.org</email>
</author>
<published>2008-04-02T07:10:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=856f6ff7a3132c8e412b23a7b9157b68ac9a2baf'/>
<id>856f6ff7a3132c8e412b23a7b9157b68ac9a2baf</id>
<content type='text'>
They are redundant as this file is linked in iff CONFIG_NET is turned
on.

Signed-off-by: Denis V. Lunev &lt;den@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
They are redundant as this file is linked in iff CONFIG_NET is turned
on.

Signed-off-by: Denis V. Lunev &lt;den@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[NETNS]: Compile NET /proc support only if CONFIG_NET is set.</title>
<updated>2008-03-27T21:25:53+00:00</updated>
<author>
<name>Denis V. Lunev</name>
<email>den@openvz.org</email>
</author>
<published>2008-03-27T21:25:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0e5f8be1388093edc324a78ebf241170b258eba3'/>
<id>0e5f8be1388093edc324a78ebf241170b258eba3</id>
<content type='text'>
This fix broken compilation for 'allnoconfig'. This was introduced by
Introduced by commit 1218854afa6f659be90b748cf1bc7badee954a35 ("[NET]
NETNS: Omit seq_net_private-&gt;net without CONFIG_NET_NS.")

Signed-off-by: Denis V. Lunev &lt;den@openvz.org&gt;
Acked-by: YOSHIFUJI Hideaki &lt;yoshfuji@linux-ipv6.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This fix broken compilation for 'allnoconfig'. This was introduced by
Introduced by commit 1218854afa6f659be90b748cf1bc7badee954a35 ("[NET]
NETNS: Omit seq_net_private-&gt;net without CONFIG_NET_NS.")

Signed-off-by: Denis V. Lunev &lt;den@openvz.org&gt;
Acked-by: YOSHIFUJI Hideaki &lt;yoshfuji@linux-ipv6.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[NET] NETNS: Omit seq_net_private-&gt;net without CONFIG_NET_NS.</title>
<updated>2008-03-25T19:39:56+00:00</updated>
<author>
<name>YOSHIFUJI Hideaki</name>
<email>yoshfuji@linux-ipv6.org</email>
</author>
<published>2008-03-25T17:36:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1218854afa6f659be90b748cf1bc7badee954a35'/>
<id>1218854afa6f659be90b748cf1bc7badee954a35</id>
<content type='text'>
Without CONFIG_NET_NS, no namespace other than &amp;init_net exists,
no need to store net in seq_net_private.

Signed-off-by: YOSHIFUJI Hideaki &lt;yoshfuji@linux-ipv6.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Without CONFIG_NET_NS, no namespace other than &amp;init_net exists,
no need to store net in seq_net_private.

Signed-off-by: YOSHIFUJI Hideaki &lt;yoshfuji@linux-ipv6.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[NET]: Make /proc/net a symlink on /proc/self/net (v3)</title>
<updated>2008-03-07T19:08:40+00:00</updated>
<author>
<name>Pavel Emelyanov</name>
<email>xemul@openvz.org</email>
</author>
<published>2008-03-07T19:08:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e9720acd728a46cb40daa52c99a979f7c4ff195c'/>
<id>e9720acd728a46cb40daa52c99a979f7c4ff195c</id>
<content type='text'>
Current /proc/net is done with so called "shadows", but current
implementation is broken and has little chances to get fixed.

The problem is that dentries subtree of /proc/net directory has
fancy revalidation rules to make processes living in different
net namespaces see different entries in /proc/net subtree, but
currently, tasks see in the /proc/net subdir the contents of any
other namespace, depending on who opened the file first.

The proposed fix is to turn /proc/net into a symlink, which points
to /proc/self/net, which in turn shows what previously was in
/proc/net - the network-related info, from the net namespace the
appropriate task lives in.

# ls -l /proc/net
lrwxrwxrwx  1 root root 8 Mar  5 15:17 /proc/net -&gt; self/net

In other words - this behaves like /proc/mounts, but unlike
"mounts", "net" is not a file, but a directory.

Changes from v2:
* Fixed discrepancy of /proc/net nlink count and selinux labeling
  screwup pointed out by Stephen.

  To get the correct nlink count the -&gt;getattr callback for /proc/net
  is overridden to read one from the net-&gt;proc_net entry.

  To make selinux still work the net-&gt;proc_net entry is initialized
  properly, i.e. with the "net" name and the proc_net parent.

Selinux fixes are
Acked-by:  Stephen Smalley &lt;sds@tycho.nsa.gov&gt;

Changes from v1:
* Fixed a task_struct leak in get_proc_task_net, pointed out by Paul.

Signed-off-by: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Acked-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Current /proc/net is done with so called "shadows", but current
implementation is broken and has little chances to get fixed.

The problem is that dentries subtree of /proc/net directory has
fancy revalidation rules to make processes living in different
net namespaces see different entries in /proc/net subtree, but
currently, tasks see in the /proc/net subdir the contents of any
other namespace, depending on who opened the file first.

The proposed fix is to turn /proc/net into a symlink, which points
to /proc/self/net, which in turn shows what previously was in
/proc/net - the network-related info, from the net namespace the
appropriate task lives in.

# ls -l /proc/net
lrwxrwxrwx  1 root root 8 Mar  5 15:17 /proc/net -&gt; self/net

In other words - this behaves like /proc/mounts, but unlike
"mounts", "net" is not a file, but a directory.

Changes from v2:
* Fixed discrepancy of /proc/net nlink count and selinux labeling
  screwup pointed out by Stephen.

  To get the correct nlink count the -&gt;getattr callback for /proc/net
  is overridden to read one from the net-&gt;proc_net entry.

  To make selinux still work the net-&gt;proc_net entry is initialized
  properly, i.e. with the "net" name and the proc_net parent.

Selinux fixes are
Acked-by:  Stephen Smalley &lt;sds@tycho.nsa.gov&gt;

Changes from v1:
* Fixed a task_struct leak in get_proc_task_net, pointed out by Paul.

Signed-off-by: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Acked-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
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