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

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>

1 files changed, 61 insertions, 0 deletions

diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 6311c15356f7..e5ce1495dc77 100644
--- 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;
+}