Re: [patch] lockdep: annotate vfs_rmdir for filesystems that take i_mutex in delete_inode

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, 26 Jul 2006 08:47:21 +0200
Arjan van de Ven <[email protected]> wrote:

> On Tue, 2006-07-25 at 22:33 -0700, Andrew Morton wrote:
> > On Wed, 26 Jul 2006 00:16:42 +0200
> > The VFS takes the directory i_mutex and reiserfs_delete_inode() takes the
> > to-be-deleted file's i_mutex.
> > 
> > That's notabug and lockdep will need to be taught about it.
> 
> [2nd try, now with coffee]
> 
> This is another 3 level locking ordering:
> do_rmdir takes the mutex of the parent directory
> vfs_rmdir takes the mutex of the victim
> shrink_dcache_parent ends up in the reiser delete_inode which takes the
> mutex of dead children of the victim
> 
> the I_MUTEX ordering rules are
> 
> I_MUTEX_PARENT -> I_MUTEX_CHILD -> <normal>
> 
> do_rmdir already has I_MUTEX_PARENT, delete_inode does <normal> so
> vfs_rmdir needs I_MUTEX_CHILD (which is also logical)
> 
> Signed-off-by: Arjan van de Ven <[email protected]>
> 
> Index: linux-2.6.18-rc2-git5/fs/namei.c
> ===================================================================
> --- linux-2.6.18-rc2-git5.orig/fs/namei.c
> +++ linux-2.6.18-rc2-git5/fs/namei.c
> @@ -1967,7 +1967,7 @@ int vfs_rmdir(struct inode *dir, struct 
>  
>  	DQUOT_INIT(dir);
>  
> -	mutex_lock(&dentry->d_inode->i_mutex);
> +	mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
>  	dentry_unhash(dentry);
>  	if (d_mountpoint(dentry))
>  		error = -EBUSY;

If there's a reason why a filesystem shuld take an i_mutex under
vfs_rmdir() then fine.  But I don't think there is, in which case the
warning can be kept.

Can a reiserfs person please comment?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux