linux.git/fs/sysfs/mount.c, branch v2.6.28 Linux kernel source tree sysfs: Support sysfs_notify from atomic context with new sysfs_notify_dirent 2008-10-16T16:24:47+00:00 Neil Brown neilb@suse.de 2008-07-15T22:58:04+00:00 f1282c844e86db5a041afa41335b5f9eea6cec0c Support sysfs_notify from atomic context with new sysfs_notify_dirent sysfs_notify currently takes sysfs_mutex. This means that it cannot be called in atomic context. sysfs_mutex is sometimes held over a malloc (sysfs_rename_dir) so it can block on low memory. In md I want to be able to notify on a sysfs attribute from atomic context, and I don't want to block on low memory because I could be in the writeout path for freeing memory. So: - export the "sysfs_dirent" structure along with sysfs_get, sysfs_put and sysfs_get_dirent so I can get the sysfs_dirent that I want to notify on and hold it in an md structure. - split sysfs_notify_dirent out of sysfs_notify so the sysfs_dirent can be notified on with no blocking (just a spinlock). Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
Support sysfs_notify from atomic context with new sysfs_notify_dirent

sysfs_notify currently takes sysfs_mutex.
This means that it cannot be called in atomic context.
sysfs_mutex  is sometimes held over a malloc (sysfs_rename_dir)
so it can block on low memory.

In md I want to be able to notify on a sysfs attribute from
atomic context, and I don't want to block on low memory because I
could be in the writeout path for freeing memory.

So:
 - export the "sysfs_dirent" structure along with sysfs_get, sysfs_put
   and sysfs_get_dirent so I can get the sysfs_dirent that I want to
   notify on and hold it in an md structure.
 - split sysfs_notify_dirent out of sysfs_notify so the sysfs_dirent
   can be notified on with no blocking (just a spinlock).

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fs: replace remaining __FUNCTION__ occurrences 2008-04-30T15:29:54+00:00 Harvey Harrison harvey.harrison@gmail.com 2008-04-30T07:55:09+00:00 8e24eea728068bbeb6a3c500b848f883a20bf225 __FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: bdi init hooks 2007-10-17T15:42:45+00:00 Peter Zijlstra a.p.zijlstra@chello.nl 2007-10-17T06:25:46+00:00 e0bf68ddec4f4f90e5871404be4f1854c17f3120 provide BDI constructor/destructor hooks [akpm@linux-foundation.org: compile fix] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
provide BDI constructor/destructor hooks

[akpm@linux-foundation.org: compile fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sysfs: add copyrights 2007-10-12T21:51:12+00:00 Tejun Heo htejun@gmail.com 2007-09-20T08:31:38+00:00 6d66f5cd26e4c482e986130b7572f2735a0f7e8b Sysfs has gone through considerable amount of reimplementation. Add copyrights. Any objections? :-) Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
Sysfs has gone through considerable amount of reimplementation.  Add
copyrights.  Any objections?  :-)

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: make sysfs_root a regular directory dirent 2007-10-12T21:51:11+00:00 Tejun Heo htejun@gmail.com 2007-09-20T07:05:12+00:00 dc2f75f0e0cac645c22c85bcf429683b3fa0d2d9 sysfs_root is different from a regular directory dirent in that it's of type SYSFS_ROOT and doesn't have a name. These differences aren't used by anybody and only adds to complexity. Make sysfs_root a regular directory dirent. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
sysfs_root is different from a regular directory dirent in that it's
of type SYSFS_ROOT and doesn't have a name.  These differences aren't
used by anybody and only adds to complexity.  Make sysfs_root a
regular directory dirent.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: Remove s_dentry 2007-10-12T21:51:08+00:00 Eric W. Biederman ebiederm@xmission.com 2007-08-20T12:36:30+00:00 5a26b79c426f8e55ebf7204cb138eb6b1645d4d3 The only uses of s_dentry left are the code that maintains s_dentry and trivial users that don't actually need it. So this patch removes the s_dentry maintenance code and restructures the trivial uses to use something else. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
The only uses of s_dentry left are the code that maintains
s_dentry and trivial users that don't actually need it.
So this patch removes the s_dentry maintenance code and
restructures the trivial uses to use something else.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: Make sysfs_mount static 2007-10-12T21:51:07+00:00 Eric W. Biederman ebiederm@xmission.com 2007-08-20T12:36:30+00:00 7d0c7d676cc066413e1583b5af9fba8011972d41 This patch modifies the users of sysfs_mount to use sysfs_root instead (which is what they are looking for). It then makes sysfs_mount static to keep people from using it by accident. The net result is slightly faster and cleaner code. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
This patch modifies the users of sysfs_mount to use sysfs_root
instead (which is what they are looking for).  It then
makes sysfs_mount static to keep people from using it
by accident.

The net result is slightly faster and cleaner code.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: Use kill_anon_super 2007-10-12T21:51:07+00:00 Eric W. Biederman ebiederm@xmission.com 2007-08-20T12:36:29+00:00 0333cd8a3f4249fde2c50929a6eac35245fc685b Since sysfs no longer stores fs directory information in the dcache on a permanent basis kill_litter_super it is inappropriate and actively wrong. It will decrement the count on all dentries left in the dcache before trying to free them. At the moment this is not biting us only because we never unmount sysfs. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
Since sysfs no longer stores fs directory information in the dcache
on a permanent basis kill_litter_super it is inappropriate and actively
wrong.  It will decrement the count on all dentries left in the
dcache before trying to free them.

At the moment this is not biting us only because we never unmount sysfs.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: Move all of inode initialization into sysfs_init_inode 2007-10-12T21:51:07+00:00 Eric W. Biederman ebiederm@xmission.com 2007-08-20T12:36:29+00:00 372e88bd1922228e0a55228f6dc8e311d1696fa0 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs: Remove first pass at shadow directory support 2007-10-12T21:51:03+00:00 Eric W. Biederman ebiederm@xmission.com 2007-07-31T10:15:08+00:00 90bc61359de0148f8627073d68a22edc7ed9893d While shadow directories appear to be a good idea, the current scheme of controlling their creation and destruction outside of sysfs appears to be a locking and maintenance nightmare in the face of sysfs directories dynamically coming and going. Which can now occur for directories containing network devices when CONFIG_SYSFS_DEPRECATED is not set. This patch removes everything from the initial shadow directory support that allowed the shadow directory creation to be controlled at a higher level. So except for a few bits of sysfs_rename_dir everything from commit b592fcfe7f06c15ec11774b5be7ce0de3aa86e73 is now gone. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> 
While shadow directories appear to be a good idea, the current scheme
of controlling their creation and destruction outside of sysfs appears
to be a locking and maintenance nightmare in the face of sysfs
directories dynamically coming and going.  Which can now occur for
directories containing network devices when CONFIG_SYSFS_DEPRECATED is
not set.

This patch removes everything from the initial shadow directory support
that allowed the shadow directory creation to be controlled at a higher
level.  So except for a few bits of sysfs_rename_dir everything from
commit b592fcfe7f06c15ec11774b5be7ce0de3aa86e73 is now gone.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>