staging: lustre: obdclass: lu_site_purge() to handle purge-all

if the callers wants to purge all objects, then scanning
should start from the first bucket.
Signed-off-by: NAlex Zhuravlev <alexey.zhuravlev@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7038
Reviewed-on: http://review.whamcloud.com/18505Reviewed-by: NMike Pershin <mike.pershin@intel.com>
Reviewed-by: NFaccini Bruno <bruno.faccini@intel.com>
Reviewed-by: NOleg Drokin <oleg.drokin@intel.com>
Signed-off-by: NJames Simmons <jsimmons@infradead.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/obdclass/lu_object.c

@@ -338,7 +338,7 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
 	struct cfs_hash_bd	    bd2;
 	struct list_head	       dispose;
 	int		      did_sth;
-	unsigned int start;
+	unsigned int start = 0;
 	int		      count;
 	int		      bnr;
 	unsigned int i;
@@ -351,7 +351,8 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
 	 * Under LRU list lock, scan LRU list and move unreferenced objects to
 	 * the dispose list, removing them from LRU and hash table.
 	 */
-	start = s->ls_purge_start;
+	if (nr != ~0)
+		start = s->ls_purge_start;
 	bnr = (nr == ~0) ? -1 : nr / (int)CFS_HASH_NBKT(s->ls_obj_hash) + 1;
  again:
 	/*