staging/lustre/xattr: xattr data may be gone with lock held

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>

diff --git a/drivers/staging/lustre/lustre/llite/xattr_cache.c b/drivers/staging/lustre/lustre/llite/xattr_cache.c
index da190f92d14079fc97c7be2c188c47d8c257f4db..69ea92adf4f1ffbdbc1e1607d1aee25cdc93c07e 100644 (file)
--- a/drivers/staging/lustre/lustre/llite/xattr_cache.c
+++ b/drivers/staging/lustre/lustre/llite/xattr_cache.c
@@ -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. */