linux-toradex.git/fs/sysfs, branch v2.6.29

Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6

2009-01-26T18:40:28+00:00

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  klist.c: bit 0 in pointer can't be used as flag
  debugfs: introduce stub for debugfs_create_size_t() when DEBUG_FS=n
  sysfs: fix problems with binary files
  PNP: fix broken pnp lowercasing for acpi module aliases
  driver core: Convert '/' to '!' in dev_set_name()

fs/Kconfig: move sysfs out

2009-01-22T10:15:56+00:00

Signed-off-by: Alexey Dobriyan

sysfs: fix problems with binary files

2009-01-21T04:52:09+00:00

Some sysfs binary files don't like having 0 passed to them as a size.
Fix this up at the root by just returning to the vfs if userspace asks
us for a zero sized buffer.

Thanks to Pavel Roskin for pointing this out.

Reported-by: Pavel Roskin 
Signed-off-by: Greg Kroah-Hartman

zero i_uid/i_gid on inode allocation

2009-01-05T16:54:28+00:00

... and don't bother in callers.  Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.

i_mode is not worth the effort; it has no common default value.

Signed-off-by: Al Viro

[PATCH] fix ->llseek for more directories

2008-10-23T09:13:21+00:00

With this patch all directory fops instances that have a readdir
that doesn't take the BKL are switched to generic_file_llseek.

Signed-off-by: Christoph Hellwig

kobject: Cleanup kobject_rename and !CONFIG_SYSFS

2008-10-16T16:24:52+00:00

It finally dawned on me what the clean fix to sysfs_rename_dir
calling kobject_set_name is.  Move the work into kobject_rename
where it belongs.  The callers serialize us anyway so this is
safe.

Signed-off-by: Eric W. Biederman 
Acked-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: Make dir and name args to sysfs_notify() const

2008-10-16T16:24:51+00:00

Because they can be, and because code like this produces a warning if
they're not:

struct device_attribute dev_attr;

sysfs_notify(&kobj, NULL, dev_attr.attr.name);

Signed-off-by: Trent Piepho 
CC: Neil Brown 
Signed-off-by: Greg Kroah-Hartman

sysfs: use ilookup5() instead of ilookup5_nowait()

2008-10-16T16:24:51+00:00

As inode creation is protected by sysfs_mutex, ilookup5_nowait()
always either fails to find at all or finds one which is fully
initialized, so using ilookup5_nowait() or ilookup5() doesn't make any
difference.  Switch to ilookup5() as it's planned to be removed.  This
change also makes lookup return value handling a bit simpler.

This change was suggested by Al Viro.

Signed-off-by: Tejun Heo 
Cc: Al Viro 
Signed-off-by: Greg Kroah-Hartman

sysfs: fix deadlock

2008-10-16T16:24:50+00:00

On Thu, Sep 11, 2008 at 10:27:10AM +0200, Ingo Molnar wrote:

> and it's working fine on most boxes. One testbox found this new locking
> scenario:
>
> PM: Adding info for No Bus:vcsa7
> EDAC DEBUG: MC0: i82860_check()
>
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.27-rc6-tip #1
> -------------------------------------------------------
> X/4873 is trying to acquire lock:
>  (&bb->mutex){--..}, at: [] mmap+0x40/0xa0
>
> but task is already holding lock:
>  (&mm->mmap_sem){----}, at: [] sys_mmap2+0x8e/0xc0
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #1 (&mm->mmap_sem){----}:
>        [] validate_chain+0xa96/0xf50
>        [] __lock_acquire+0x2cb/0x5b0
>        [] lock_acquire+0x89/0xc0
>        [] might_fault+0x6b/0x90
>        [] copy_to_user+0x38/0x60
>        [] read+0xfb/0x170
>        [] vfs_read+0x95/0x110
>        [] sys_pread64+0x63/0x80
>        [] sysenter_do_call+0x12/0x43
>        [] 0xffffffff
>
> -> #0 (&bb->mutex){--..}:
>        [] validate_chain+0x6b7/0xf50
>        [] __lock_acquire+0x2cb/0x5b0
>        [] lock_acquire+0x89/0xc0
>        [] __mutex_lock_common+0xab/0x3c0
>        [] mutex_lock_nested+0x38/0x50
>        [] mmap+0x40/0xa0
>        [] mmap_region+0x14e/0x450
>        [] do_mmap_pgoff+0x2ef/0x310
>        [] sys_mmap2+0xad/0xc0
>        [] sysenter_do_call+0x12/0x43
>        [] 0xffffffff
>
> other info that might help us debug this:
>
> 1 lock held by X/4873:
>  #0:  (&mm->mmap_sem){----}, at: [] sys_mmap2+0x8e/0xc0
>
> stack backtrace:
> Pid: 4873, comm: X Not tainted 2.6.27-rc6-tip #1
>  [] print_circular_bug_tail+0x79/0xc0
>  [] validate_chain+0x6b7/0xf50
>  [] ? trace_hardirqs_off_caller+0x15/0xb0
>  [] __lock_acquire+0x2cb/0x5b0
>  [] lock_acquire+0x89/0xc0
>  [] ? mmap+0x40/0xa0
>  [] __mutex_lock_common+0xab/0x3c0
>  [] ? mmap+0x40/0xa0
>  [] mutex_lock_nested+0x38/0x50
>  [] ? mmap+0x40/0xa0
>  [] mmap+0x40/0xa0
>  [] mmap_region+0x14e/0x450
>  [] ? arch_get_unmapped_area_topdown+0xf8/0x160
>  [] do_mmap_pgoff+0x2ef/0x310
>  [] sys_mmap2+0xad/0xc0
>  [] sysenter_do_call+0x12/0x43
>  [] ? __switch_to+0x130/0x220
>  =======================
> evbug.c: Event. Dev: input3, Type: 20, Code: 0, Value: 500
> warning: `sudo' uses deprecated v2 capabilities in a way that may be insecure.
>
> i've attached the config.
>
> at first sight it looks like a genuine bug in fs/sysfs/bin.c?

Yes, it is a real bug by the looks. bin.c takes bb->mutex under mmap_sem
when it is mmapped, and then does its copy_*_user under bb->mutex too.

Here is a basic fix for the sysfs lor.


From: Nick Piggin 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sysfs: Support sysfs_notify from atomic context with new sysfs_notify_dirent

2008-10-16T16:24:47+00:00

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 
Acked-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman