Commit ee4bd0d9 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

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: default avatarTheodore Ts'o <tytso@mit.edu>
parent 10809df8

fs/ext4/extents.c

+8 −17
Original line number Diff line number Diff line
@@ -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;

}

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