staging/lustre/xattr: xattr data may be gone with lock held
authorLai Siyao <lai.siyao@intel.com>
Thu, 26 Mar 2015 01:53:26 +0000 (21:53 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 26 Mar 2015 10:11:44 +0000 (11:11 +0100)
Xattr cached data may be gone, but lock still held, in this case,
refetch xattr from server, otherwise client will return error.

Signed-off-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-on: http://review.whamcloud.com/12952
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3544
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/lustre/lustre/llite/xattr_cache.c

index da190f9..69ea92a 100644 (file)
@@ -295,13 +295,18 @@ static int ll_xattr_find_get_lock(struct inode *inode,
 
 
        mutex_lock(&lli->lli_xattrs_enq_lock);
-       /* Try matching first. */
-       mode = ll_take_md_lock(inode, MDS_INODELOCK_XATTR, &lockh, 0, LCK_PR);
-       if (mode != 0) {
-               /* fake oit in mdc_revalidate_lock() manner */
-               oit->d.lustre.it_lock_handle = lockh.cookie;
-               oit->d.lustre.it_lock_mode = mode;
-               goto out;
+       /* inode may have been shrunk and recreated, so data is gone, match lock
+        * only when data exists. */
+       if (ll_xattr_cache_valid(lli)) {
+               /* Try matching first. */
+               mode = ll_take_md_lock(inode, MDS_INODELOCK_XATTR, &lockh, 0,
+                                      LCK_PR);
+               if (mode != 0) {
+                       /* fake oit in mdc_revalidate_lock() manner */
+                       oit->d.lustre.it_lock_handle = lockh.cookie;
+                       oit->d.lustre.it_lock_mode = mode;
+                       goto out;
+               }
        }
 
        /* Enqueue if the lock isn't cached locally. */