Messages in this thread | | | Date | Wed, 26 Jul 2006 00:04:52 -0700 | From | Andrew Morton <> | Subject | Re: [patch] lockdep: annotate vfs_rmdir for filesystems that take i_mutex in delete_inode |
| |
On Wed, 26 Jul 2006 08:47:21 +0200 Arjan van de Ven <arjan@linux.intel.com> 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 <arjan@linux.intel.com> > > 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |