Ocfs2/move_extents: lock allocators and reserve metadata blocks and data clusters...

ocfs2_lock_allocators_move_extents() was like the common ocfs2_lock_allocators(),
to lock metadata and data alloctors during extents moving, reserve appropriate
metadata blocks and data clusters, also performa a best- effort to calculate the
credits for journal transaction in one run of movement.

Signed-off-by: Tristan Ye <tristan.ye@oracle.com>

diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 6311c15356f7340ed893675c7ba4b80321a521a0..e5ce1495dc77e4c388fa4fe4ffbafd04488313ec 100644 (file)
--- a/fs/ocfs2/move_extents.c
+++ b/fs/ocfs2/move_extents.c
@@ -54,3 +54,64 @@ struct ocfs2_move_extents_context {
        struct ocfs2_alloc_context *data_ac;
        struct ocfs2_cached_dealloc_ctxt dealloc;
 };
+
+/*
+ * lock allocators, and reserving appropriate number of bits for
+ * meta blocks and data clusters.
+ *
+ * in some cases, we don't need to reserve clusters, just let data_ac
+ * be NULL.
+ */
+static int ocfs2_lock_allocators_move_extents(struct inode *inode,
+                                       struct ocfs2_extent_tree *et,
+                                       u32 clusters_to_move,
+                                       u32 extents_to_split,
+                                       struct ocfs2_alloc_context **meta_ac,
+                                       struct ocfs2_alloc_context **data_ac,
+                                       int extra_blocks,
+                                       int *credits)
+{
+       int ret, num_free_extents;
+       unsigned int max_recs_needed = 2 * extents_to_split + clusters_to_move;
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+       num_free_extents = ocfs2_num_free_extents(osb, et);
+       if (num_free_extents < 0) {
+               ret = num_free_extents;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       if (!num_free_extents ||
+           (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed))
+               extra_blocks += ocfs2_extend_meta_needed(et->et_root_el);
+
+       ret = ocfs2_reserve_new_metadata_blocks(osb, extra_blocks, meta_ac);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       if (data_ac) {
+               ret = ocfs2_reserve_clusters(osb, clusters_to_move, data_ac);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       }
+
+       *credits += ocfs2_calc_extend_credits(osb->sb, et->et_root_el,
+                                             clusters_to_move + 2);
+
+       mlog(0, "reserve metadata_blocks: %d, data_clusters: %u, credits: %d\n",
+            extra_blocks, clusters_to_move, *credits);
+out:
+       if (ret) {
+               if (*meta_ac) {
+                       ocfs2_free_alloc_context(*meta_ac);
+                       *meta_ac = NULL;
+               }
+       }
+
+       return ret;
+}