Btrfs: fix fsync xattr loss in the fast fsync path
[sfrench/cifs-2.6.git] / fs / btrfs / tree-log.c
index 76c4f9d1b80a38a77e4eae00b0f11893beb4898e..66f87156882f17e2b4028aa475d63a10f2949123 100644 (file)
@@ -4117,6 +4117,86 @@ static int logged_inode_size(struct btrfs_root *log, struct inode *inode,
        return 0;
 }
 
+/*
+ * At the moment we always log all xattrs. This is to figure out at log replay
+ * time which xattrs must have their deletion replayed. If a xattr is missing
+ * in the log tree and exists in the fs/subvol tree, we delete it. This is
+ * because if a xattr is deleted, the inode is fsynced and a power failure
+ * happens, causing the log to be replayed the next time the fs is mounted,
+ * we want the xattr to not exist anymore (same behaviour as other filesystems
+ * with a journal, ext3/4, xfs, f2fs, etc).
+ */
+static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
+                               struct btrfs_root *root,
+                               struct inode *inode,
+                               struct btrfs_path *path,
+                               struct btrfs_path *dst_path)
+{
+       int ret;
+       struct btrfs_key key;
+       const u64 ino = btrfs_ino(inode);
+       int ins_nr = 0;
+       int start_slot = 0;
+
+       key.objectid = ino;
+       key.type = BTRFS_XATTR_ITEM_KEY;
+       key.offset = 0;
+
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       if (ret < 0)
+               return ret;
+
+       while (true) {
+               int slot = path->slots[0];
+               struct extent_buffer *leaf = path->nodes[0];
+               int nritems = btrfs_header_nritems(leaf);
+
+               if (slot >= nritems) {
+                       if (ins_nr > 0) {
+                               u64 last_extent = 0;
+
+                               ret = copy_items(trans, inode, dst_path, path,
+                                                &last_extent, start_slot,
+                                                ins_nr, 1, 0);
+                               /* can't be 1, extent items aren't processed */
+                               ASSERT(ret <= 0);
+                               if (ret < 0)
+                                       return ret;
+                               ins_nr = 0;
+                       }
+                       ret = btrfs_next_leaf(root, path);
+                       if (ret < 0)
+                               return ret;
+                       else if (ret > 0)
+                               break;
+                       continue;
+               }
+
+               btrfs_item_key_to_cpu(leaf, &key, slot);
+               if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
+                       break;
+
+               if (ins_nr == 0)
+                       start_slot = slot;
+               ins_nr++;
+               path->slots[0]++;
+               cond_resched();
+       }
+       if (ins_nr > 0) {
+               u64 last_extent = 0;
+
+               ret = copy_items(trans, inode, dst_path, path,
+                                &last_extent, start_slot,
+                                ins_nr, 1, 0);
+               /* can't be 1, extent items aren't processed */
+               ASSERT(ret <= 0);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return 0;
+}
+
 /* log a single inode in the tree log.
  * At least one parent directory for this inode must exist in the tree
  * or be logged already.
@@ -4289,6 +4369,25 @@ again:
                if (min_key.type == BTRFS_INODE_ITEM_KEY)
                        need_log_inode_item = false;
 
+               /* Skip xattrs, we log them later with btrfs_log_all_xattrs() */
+               if (min_key.type == BTRFS_XATTR_ITEM_KEY) {
+                       if (ins_nr == 0)
+                               goto next_slot;
+                       ret = copy_items(trans, inode, dst_path, path,
+                                        &last_extent, ins_start_slot,
+                                        ins_nr, inode_only, logged_isize);
+                       if (ret < 0) {
+                               err = ret;
+                               goto out_unlock;
+                       }
+                       ins_nr = 0;
+                       if (ret) {
+                               btrfs_release_path(path);
+                               continue;
+                       }
+                       goto next_slot;
+               }
+
                src = path->nodes[0];
                if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
                        ins_nr++;
@@ -4356,6 +4455,11 @@ next_slot:
                ins_nr = 0;
        }
 
+       btrfs_release_path(path);
+       btrfs_release_path(dst_path);
+       err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path);
+       if (err)
+               goto out_unlock;
 log_extents:
        btrfs_release_path(path);
        btrfs_release_path(dst_path);