linux.git/fs/sysfs/dir.c, branch v2.6.22-rc4

[PATCH] Fix 2.6.21 rfcomm lockups

2007-03-06T17:30:24+00:00

Any attempt to open/use a bluetooth rfcomm device locks up
scheduling completely on my machine.

Interrupts (ping, alt-sysrq) seem to be alive, but nothing else.

This was working fine in 2.6.20, broken now in 2.6.21-rc2-git*

Reverting this change (below) fixes it:

| author    Marcel Holtmann 
|      Sat, 17 Feb 2007 22:58:57 +0000 (23:58 +0100)
| committer    David S. Miller 
|      Mon, 26 Feb 2007 19:42:41 +0000 (11:42 -0800)
| commit    c1a3313698895d8ad4760f98642007bf236af2e8
| tree    337a876f727061362b6a169f8759849c105b8f7a    tree | snapshot
| parent    f5ffd4620aba9e55656483ae1ef5c79ba81f5403    commit | diff
| | [Bluetooth] Make use of device_move() for RFCOMM TTY devices
| | In the case of bound RFCOMM TTY devices the parent is not available
| before its usage. So when opening a RFCOMM TTY device, move it to
| the corresponding ACL device as a child. When closing the device,
| move it back to the virtual device tree.
| Signed-off-by: Marcel Holtmann 

The simplest fix for this bug is to prevent sysfs_move_dir()
from self-deadlocking when (old_parent == new_parent).

This patch prevents total system lockup when using rfcomm devices.

Signed-off-by:  Mark Lord 
Acked-by: Cornelia Huck 
Cc: Greg KH 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] mark struct inode_operations const 3

2007-02-12T17:48:46+00:00

Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Transform kmem_cache_alloc()+memset(0) -> kmem_cache_zalloc().

2007-02-11T18:51:27+00:00

Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
corresponding "kmem_cache_zalloc()" call.

Signed-off-by: Robert P. J. Day 
Cc: "Luck, Tony" 
Cc: Andi Kleen 
Cc: Roland McGrath 
Cc: James Bottomley 
Cc: Greg KH 
Acked-by: Joel Becker 
Cc: Steven Whitehouse 
Cc: Jan Kara 
Cc: Michael Halcrow 
Cc: "David S. Miller" 
Cc: Stephen Smalley 
Cc: James Morris 
Cc: Chris Wright 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysfs: Shadow directory support

2007-02-07T18:37:14+00:00

The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*. 

What I want is a separate /sys/class/net directory in sysfs for each
network namespace, and I want to name each of them /sys/class/net.

I looked and the VFS actually allows that.  All that is needed is
for /sys/class/net to implement a follow link method to redirect
lookups to the real directory you want. 

Implementing a follow link method that is sensitive to the current
network namespace turns out to be 3 lines of code so it looks like a
clean approach.  Modifying sysfs so it doesn't get in my was is a bit
trickier. 

I am calling the concept of multiple directories all at the same path
in the filesystem shadow directories.  With the directory entry really
at that location the shadow master. 

The following patch modifies sysfs so it can handle a directory
structure slightly different from the kobject tree so I can implement
the shadow directories for handling /sys/class/net/.

Signed-off-by: Eric W. Biederman 
Cc: Maneesh Soni 
Signed-off-by: Greg Kroah-Hartman

Driver core: fix race in sysfs between sysfs_remove_file() and read()/write()

2007-02-07T18:37:13+00:00

This patch prevents a race between IO and removing a file from sysfs.
It introduces a list of sysfs_buffers associated with a file at the inode.
Upon removal of a file the list is walked and the buffers marked orphaned.
IO to orphaned buffers fails with -ENODEV. The driver can safely free
associated data structures or be unloaded.

Signed-off-by: Oliver Neukum 
Acked-by: Maneesh Soni 
Signed-off-by: Greg Kroah-Hartman

driver core: Allow device_move(dev, NULL).

2007-02-07T18:37:11+00:00

If we allow NULL as the new parent in device_move(), we need to make sure
that the device is placed into the same place as it would if it was
newly registered:

- Consider the device virtual tree. In order to be able to reuse code,
  setup_parent() has been tweaked a bit.
- kobject_move() can fall back to the kset's kobject.
- sysfs_move_dir() uses the sysfs root dir as fallback.

Signed-off-by: Cornelia Huck 
Cc: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

[PATCH] sysfs: change uses of f_{dentry, vfsmnt} to use f_path

2006-12-08T16:28:41+00:00

Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the sysfs
filesystem code.

Signed-off-by: Josef "Jeff" Sipek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

driver core: Introduce device_move(): move a device to a new parent.

2006-12-01T22:52:01+00:00

Provide a function device_move() to move a device to a new parent device. Add
auxilliary functions kobject_move() and sysfs_move_dir().
kobject_move() generates a new uevent of type KOBJ_MOVE, containing the
previous path (DEVPATH_OLD) in addition to the usual values. For this, a new
interface kobject_uevent_env() is created that allows to add further
environmental data to the uevent at the kobject layer.

Signed-off-by: Cornelia Huck 
Acked-by: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman

[PATCH] r/o bind mount prepwork: inc_nlink() helper

2006-10-01T07:39:30+00:00

This is mostly included for parity with dec_nlink(), where we will have some
more hooks.  This one should stay pretty darn straightforward for now.

Signed-off-by: Dave Hansen 
Acked-by: Christoph Hellwig 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysfs: Make poll behaviour consistent

2006-09-26T04:08:36+00:00

When no events have been reported by sysfs_notify(), sd->s_events
was previously set to zero.  The initial value for new readers is
also zero, so poll was blocking, regardless of whether the attribute
was read by the process or not.

Make poll behave consistently by setting the initial value of
sd->s_events to non-zero.

Signed-off-by: Juha Yrjola 
Signed-off-by: Greg Kroah-Hartman