1 files changed, 27 insertions, 12 deletions

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index 7eafe468a29c..b2e3ff347620 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -1346,6 +1346,11 @@ static void nilfs_btree_shrink(struct nilfs_bmap *btree,
         path[level].bp_bh = NULL;
 }
 
+static void nilfs_btree_nop(struct nilfs_bmap *btree,
+                            struct nilfs_btree_path *path,
+                            int level, __u64 *keyp, __u64 *ptrp)
+{
+}
 
 static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
                                       struct nilfs_btree_path *path,
@@ -1356,20 +1361,19 @@ static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
         struct buffer_head *bh;
         struct nilfs_btree_node *node, *parent, *sib;
         __u64 sibptr;
-        int pindex, level, ncmin, ncmax, ncblk, ret;
+        int pindex, dindex, level, ncmin, ncmax, ncblk, ret;
 
         ret = 0;
         stats->bs_nblocks = 0;
         ncmin = NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
         ncblk = nilfs_btree_nchildren_per_block(btree);
 
-        for (level = NILFS_BTREE_LEVEL_NODE_MIN;
+        for (level = NILFS_BTREE_LEVEL_NODE_MIN, dindex = path[level].bp_index;
              level < nilfs_btree_height(btree) - 1;
              level++) {
                 node = nilfs_btree_get_nonroot_node(path, level);
                 path[level].bp_oldreq.bpr_ptr =
-                        nilfs_btree_node_get_ptr(node, path[level].bp_index,
-                                                 ncblk);
+                        nilfs_btree_node_get_ptr(node, dindex, ncblk);
                 ret = nilfs_bmap_prepare_end_ptr(btree,
                                                  &path[level].bp_oldreq, dat);
                 if (ret < 0)
@@ -1383,6 +1387,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
 
                 parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
                 pindex = path[level + 1].bp_index;
+                dindex = pindex;
 
                 if (pindex > 0) {
                         /* left sibling */
@@ -1421,6 +1426,14 @@ static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
                                 path[level].bp_sib_bh = bh;
                                 path[level].bp_op = nilfs_btree_concat_right;
                                 stats->bs_nblocks++;
+                                /*
+                                 * When merging right sibling node
+                                 * into the current node, pointer to
+                                 * the right sibling node must be
+                                 * terminated instead.  The adjustment
+                                 * below is required for that.
+                                 */
+                                dindex = pindex + 1;
                                 /* continue; */
                         }
                 } else {
@@ -1431,29 +1444,31 @@ static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
                             NILFS_BTREE_ROOT_NCHILDREN_MAX) {
                                 path[level].bp_op = nilfs_btree_shrink;
                                 stats->bs_nblocks += 2;
+                                level++;
+                                path[level].bp_op = nilfs_btree_nop;
+                                goto shrink_root_child;
                         } else {
                                 path[level].bp_op = nilfs_btree_do_delete;
                                 stats->bs_nblocks++;
+                                goto out;
                         }
-
-                        goto out;
-
                 }
         }
 
+        /* child of the root node is deleted */
+        path[level].bp_op = nilfs_btree_do_delete;
+        stats->bs_nblocks++;
+
+shrink_root_child:
         node = nilfs_btree_get_root(btree);
         path[level].bp_oldreq.bpr_ptr =
-                nilfs_btree_node_get_ptr(node, path[level].bp_index,
+                nilfs_btree_node_get_ptr(node, dindex,
                                          NILFS_BTREE_ROOT_NCHILDREN_MAX);
 
         ret = nilfs_bmap_prepare_end_ptr(btree, &path[level].bp_oldreq, dat);
         if (ret < 0)
                 goto err_out_child_node;
 
-        /* child of the root node is deleted */
-        path[level].bp_op = nilfs_btree_do_delete;
-        stats->bs_nblocks++;
-
         /* success */
  out:
         *levelp = level;