btrfs: add helper to delete a dir entry from a log tree

Move the code that finds and deletes a logged dir entry out of
btrfs_del_dir_entries_in_log() into a helper function. This new helper
function will be used by another patch in the same series, and serves
to avoid having duplicated logic.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index a0364f1..2f4f349 100644 (file)
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3509,6 +3509,41 @@ static bool inode_logged(struct btrfs_trans_handle *trans,
 }
 
 /*
+ * Delete a directory entry from the log if it exists.
+ *
+ * Returns < 0 on error
+ *           1 if the entry does not exists
+ *           0 if the entry existed and was successfully deleted
+ */
+static int del_logged_dentry(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *log,
+                            struct btrfs_path *path,
+                            u64 dir_ino,
+                            const char *name, int name_len,
+                            u64 index)
+{
+       struct btrfs_dir_item *di;
+
+       /*
+        * We only log dir index items of a directory, so we don't need to look
+        * for dir item keys.
+        */
+       di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
+                                        index, name, name_len, -1);
+       if (IS_ERR(di))
+               return PTR_ERR(di);
+       else if (!di)
+               return 1;
+
+       /*
+        * We do not need to update the size field of the directory's
+        * inode item because on log replay we update the field to reflect
+        * all existing entries in the directory (see overwrite_item()).
+        */
+       return btrfs_delete_one_dir_name(trans, log, path, di);
+}
+
+/*
  * If both a file and directory are logged, and unlinks or renames are
  * mixed in, we have a few interesting corners:
  *
@@ -3534,12 +3569,8 @@ void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
                                  const char *name, int name_len,
                                  struct btrfs_inode *dir, u64 index)
 {
-       struct btrfs_root *log;
-       struct btrfs_dir_item *di;
        struct btrfs_path *path;
        int ret;
-       int err = 0;
-       u64 dir_ino = btrfs_ino(dir);
 
        if (!inode_logged(trans, dir))
                return;
@@ -3550,41 +3581,18 @@ void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
 
        mutex_lock(&dir->log_mutex);
 
-       log = root->log_root;
        path = btrfs_alloc_path();
        if (!path) {
-               err = -ENOMEM;
+               ret = -ENOMEM;
                goto out_unlock;
        }
 
-       /*
-        * We only log dir index items of a directory, so we don't need to look
-        * for dir item keys.
-        */
-       di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
-                                        index, name, name_len, -1);
-       if (IS_ERR(di)) {
-               err = PTR_ERR(di);
-               goto fail;
-       }
-       if (di) {
-               ret = btrfs_delete_one_dir_name(trans, log, path, di);
-               if (ret) {
-                       err = ret;
-                       goto fail;
-               }
-       }
-
-       /*
-        * We do not need to update the size field of the directory's inode item
-        * because on log replay we update the field to reflect all existing
-        * entries in the directory (see overwrite_item()).
-        */
-fail:
+       ret = del_logged_dentry(trans, root->log_root, path, btrfs_ino(dir),
+                               name, name_len, index);
        btrfs_free_path(path);
 out_unlock:
        mutex_unlock(&dir->log_mutex);
-       if (err < 0)
+       if (ret < 0)
                btrfs_set_log_full_commit(trans);
        btrfs_end_log_trans(root);
 }