staging: lustre: llite: move dir cache to MDC layer

Move directory entries cache from llite to MDC, so client
side dir stripe will use independent hash function(in LMV),
which does not need to be tightly coupled with the backend
storage dir-entry hash function. With striped directory, it
will be 2-tier hash, LMV calculate hash value according to the
name and hash-type in layout, then each MDT will store these
entry in disk by its own hash.
Signed-off-by: wang di <di.wang@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3531
Reviewed-on: http://review.whamcloud.com/7043Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/include/lustre_lite.h

@@ -80,17 +80,6 @@ static inline void ll_dir_chain_fini(struct ll_dir_chain *chain)
 {
 }
 
-static inline unsigned long hash_x_index(__u64 hash, int hash64)
-{
-	if (BITS_PER_LONG == 32 && hash64)
-		hash >>= 32;
-	/* save hash 0 as index 0 because otherwise we'll save it at
-	 * page index end (~0UL) and it causes truncate_inode_pages_range()
-	 * to loop forever.
-	 */
-	return ~0UL - (hash + !hash);
-}
-
 /** @} lite */
 
 #endif

drivers/staging/lustre/lustre/llite/llite_internal.h

@@ -665,7 +665,7 @@ int ll_dir_read(struct inode *inode, __u64 *ppos, struct md_op_data *op_data,
 int ll_get_mdt_idx(struct inode *inode);
 int ll_get_mdt_idx_by_fid(struct ll_sb_info *sbi, const struct lu_fid *fid);
 struct page *ll_get_dir_page(struct inode *dir, struct md_op_data *op_data,
-			     __u64 hash, struct ll_dir_chain *chain);
+			     __u64 offset, struct ll_dir_chain *chain);
 void ll_release_page(struct inode *inode, struct page *page, bool remove);
 
 /* llite/namei.c */

drivers/staging/lustre/lustre/llite/statahead.c

@@ -1035,7 +1035,7 @@ static int ll_statahead_thread(void *arg)
 	struct ll_statahead_info *sai    = ll_sai_get(plli->lli_sai);
 	struct ptlrpc_thread     *thread = &sai->sai_thread;
 	struct ptlrpc_thread *agl_thread = &sai->sai_agl_thread;
-	struct page	      *page;
+	struct page	      *page = NULL;
 	__u64		     pos    = 0;
 	int		       first  = 0;
 	int		       rc     = 0;
@@ -1166,8 +1166,7 @@ static int ll_statahead_thread(void *arg)
 					if (!list_empty(&sai->sai_entries_received))
 						goto interpret_it;
 
-					if (unlikely(
-						!thread_is_running(thread))) {
+					if (unlikely(!thread_is_running(thread))) {
 						ll_release_page(dir, page, false);
 						rc = 0;
 						goto out;
@@ -1182,10 +1181,10 @@ static int ll_statahead_thread(void *arg)
 
 				goto keep_it;
 			}
-
 do_it:
 			ll_statahead_one(parent, name, namelen);
 		}
+
 		pos = le64_to_cpu(dp->ldp_hash_end);
 		if (pos == MDS_DIR_END_OFF) {
 			/*
@@ -1232,14 +1231,12 @@ static int ll_statahead_thread(void *arg)
 			 * Normal case: continue to the next page.
 			 */
 			ll_release_page(dir, page,
-					le32_to_cpu(dp->ldp_flags) &
-					LDF_COLLIDE);
+					le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE);
 			sai->sai_in_readpage = 1;
 			page = ll_get_dir_page(dir, op_data, pos, &chain);
 			sai->sai_in_readpage = 0;
 		}
 	}
-
 out:
 	ll_finish_md_op_data(op_data);
 	if (sai->sai_agl_valid) {
@@ -1455,7 +1452,6 @@ static int is_first_dirent(struct inode *dir, struct dentry *dentry)
 			page = ll_get_dir_page(dir, op_data, pos, &chain);
 		}
 	}
-
 out:
 	ll_dir_chain_fini(&chain);
 	ll_finish_md_op_data(op_data);

drivers/staging/lustre/lustre/mdc/mdc_internal.h

@@ -135,4 +135,12 @@ static inline int mdc_prep_elc_req(struct obd_export *exp,
 				 count);
 }
 
+static inline unsigned long hash_x_index(__u64 hash, int hash64)
+{
+	if (BITS_PER_LONG == 32 && hash64)
+		hash >>= 32;
+	/* save hash 0 with hash 1 */
+	return ~0UL - (hash + !hash);
+}
+
 #endif