1 files changed, 109 insertions, 3 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index f7a18751314a..4c50f823949c 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -966,7 +966,9 @@ static noinline int backref_in_log(struct btrfs_root *log,
         ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
 
         if (key->type == BTRFS_INODE_EXTREF_KEY) {
-                if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+                if (btrfs_find_name_in_ext_backref(path->nodes[0],
+                                                   path->slots[0],
+                                                   ref_objectid,
                                                    name, namelen, NULL))
                         match = 1;
 
@@ -1190,7 +1192,8 @@ static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
         read_extent_buffer(eb, *name, (unsigned long)&extref->name,
                            *namelen);
 
-        *index = btrfs_inode_extref_index(eb, extref);
+        if (index)
+                *index = btrfs_inode_extref_index(eb, extref);
         if (parent_objectid)
                 *parent_objectid = btrfs_inode_extref_parent(eb, extref);
 
@@ -1211,12 +1214,102 @@ static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
 
         read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
 
-        *index = btrfs_inode_ref_index(eb, ref);
+        if (index)
+                *index = btrfs_inode_ref_index(eb, ref);
 
         return 0;
 }
 
 /*
+ * Take an inode reference item from the log tree and iterate all names from the
+ * inode reference item in the subvolume tree with the same key (if it exists).
+ * For any name that is not in the inode reference item from the log tree, do a
+ * proper unlink of that name (that is, remove its entry from the inode
+ * reference item and both dir index keys).
+ */
+static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
+                                 struct btrfs_root *root,
+                                 struct btrfs_path *path,
+                                 struct btrfs_inode *inode,
+                                 struct extent_buffer *log_eb,
+                                 int log_slot,
+                                 struct btrfs_key *key)
+{
+        int ret;
+        unsigned long ref_ptr;
+        unsigned long ref_end;
+        struct extent_buffer *eb;
+
+again:
+        btrfs_release_path(path);
+        ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+        if (ret > 0) {
+                ret = 0;
+                goto out;
+        }
+        if (ret < 0)
+                goto out;
+
+        eb = path->nodes[0];
+        ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
+        ref_end = ref_ptr + btrfs_item_size_nr(eb, path->slots[0]);
+        while (ref_ptr < ref_end) {
+                char *name = NULL;
+                int namelen;
+                u64 parent_id;
+
+                if (key->type == BTRFS_INODE_EXTREF_KEY) {
+                        ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
+                                                NULL, &parent_id);
+                } else {
+                        parent_id = key->offset;
+                        ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
+                                             NULL);
+                }
+                if (ret)
+                        goto out;
+
+                if (key->type == BTRFS_INODE_EXTREF_KEY)
+                        ret = btrfs_find_name_in_ext_backref(log_eb, log_slot,
+                                                             parent_id, name,
+                                                             namelen, NULL);
+                else
+                        ret = btrfs_find_name_in_backref(log_eb, log_slot, name,
+                                                         namelen, NULL);
+
+                if (!ret) {
+                        struct inode *dir;
+
+                        btrfs_release_path(path);
+                        dir = read_one_inode(root, parent_id);
+                        if (!dir) {
+                                ret = -ENOENT;
+                                kfree(name);
+                                goto out;
+                        }
+                        ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
+                                                 inode, name, namelen);
+                        kfree(name);
+                        iput(dir);
+                        if (ret)
+                                goto out;
+                        goto again;
+                }
+
+                kfree(name);
+                ref_ptr += namelen;
+                if (key->type == BTRFS_INODE_EXTREF_KEY)
+                        ref_ptr += sizeof(struct btrfs_inode_extref);
+                else
+                        ref_ptr += sizeof(struct btrfs_inode_ref);
+        }
+        ret = 0;
+ out:
+        btrfs_release_path(path);
+        return ret;
+}
+
+/*
  * replay one inode back reference item found in the log tree.
  * eb, slot and key refer to the buffer and key found in the log tree.
  * root is the destination we are replaying into, and path is for temp
@@ -1344,6 +1437,19 @@ static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
                 }
         }
 
+        /*
+         * Before we overwrite the inode reference item in the subvolume tree
+         * with the item from the log tree, we must unlink all names from the
+         * parent directory that are in the subvolume's tree inode reference
+         * item, otherwise we end up with an inconsistent subvolume tree where
+         * dir index entries exist for a name but there is no inode reference
+         * item with the same name.
+         */
+        ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
+                                    key);
+        if (ret)
+                goto out;
+
         /* finally write the back reference in the inode */
         ret = overwrite_item(trans, root, path, eb, slot, key);
 out: