Re: [PATCH 15/13] sysfs: Protect sysfs_refresh_inode with inode mutex.

Tejun Heo
2009-11-07T02:26:59Z

Eric W. Biederman wrote:
> In general everything that writes to vfs inodes holds the
> inode mutex, so hold the inode mutex over sysfs_refresh_inode.
> The sysfs data structures don't need this but it looks like the
> vfs might.
>
> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>

Acked-by: Tejun Heo <tj@kernel.org>

Sidenote: Hmmm... Originally, sysfs completely depended on vfs locking
but with sysfs_dirent separation, the tree structure itself and some
attributes went under the protection of sysfs_mutex while leaving more
vfs oriented fields under vfs locking. This patchset makes sysfs
lazier so it can't depend on any vfs layer locking. I think you've
converted all necessary places while removing dependency on
dentry/inode from update operations but it might be a good idea to do
a audit pass over how fields are being protected now.

Thanks for your patience.

--
tejun