ext4: reuse path object in ext4_ext_shift_extents()

Now that the semantics of ext4_ext_find_extent() are much cleaner,
it's safe and more efficient to reuse the path object across the
multiple calls to ext4_ext_find_extent() in ext4_ext_shift_extents().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index c94c7480053e9e2ba97121fc0933d8f5a10ff590..22828e44a70ddcbfc0f96d1d24e4c110a1bc1193 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5306,26 +5306,21 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 
        depth = path->p_depth;
        extent = path[depth].p_ext;
-       if (!extent) {
-               ext4_ext_drop_refs(path);
-               kfree(path);
-               return ret;
-       }
+       if (!extent)
+               goto out;
 
        stop_block = le32_to_cpu(extent->ee_block) +
                        ext4_ext_get_actual_len(extent);
-       ext4_ext_drop_refs(path);
-       kfree(path);
 
        /* Nothing to shift, if hole is at the end of file */
        if (start >= stop_block)
-               return ret;
+               goto out;
 
        /*
         * Don't start shifting extents until we make sure the hole is big
         * enough to accomodate the shift.
         */
-       path = ext4_ext_find_extent(inode, start - 1, NULL, 0);
+       path = ext4_ext_find_extent(inode, start - 1, &path, 0);
        if (IS_ERR(path))
                return PTR_ERR(path);
        depth = path->p_depth;
@@ -5338,8 +5333,6 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
                ex_start = 0;
                ex_end = 0;
        }
-       ext4_ext_drop_refs(path);
-       kfree(path);
 
        if ((start == ex_start && shift > ex_start) ||
            (shift > start - ex_end))
@@ -5347,7 +5340,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 
        /* Its safe to start updating extents */
        while (start < stop_block) {
-               path = ext4_ext_find_extent(inode, start, NULL, 0);
+               path = ext4_ext_find_extent(inode, start, &path, 0);
                if (IS_ERR(path))
                        return PTR_ERR(path);
                depth = path->p_depth;
@@ -5363,19 +5356,17 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
                                path[depth].p_ext++;
                        } else {
                                start = ext4_ext_next_allocated_block(path);
-                               ext4_ext_drop_refs(path);
-                               kfree(path);
                                continue;
                        }
                }
                ret = ext4_ext_shift_path_extents(path, shift, inode,
                                handle, &start);
-               ext4_ext_drop_refs(path);
-               kfree(path);
                if (ret)
                        break;
        }
-
+out:
+       ext4_ext_drop_refs(path);
+       kfree(path);
        return ret;
 }