Commit 523f431c authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: call ext4_ext_drop_refs() from ext4_ext_find_extent() 



In nearly all of the calls to ext4_ext_find_extent() where the caller
is trying to recycle the path object, ext4_ext_drop_refs() gets called
to release the buffer heads before the path object gets overwritten.
To simplify things for the callers, and to avoid the possibility of a
memory leak, make ext4_ext_find_extent() responsible for dropping the
buffers.

Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent dfe50809

fs/ext4/extents.c

+4 −7
Original line number Diff line number Diff line
@@ -867,8 +867,10 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, 
	eh = ext_inode_hdr(inode);

	depth = ext_depth(inode);



	if (path)

		ext4_ext_drop_refs(path);

	else {

		/* account possible depth increase */

	if (!path) {

		path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),

				GFP_NOFS);

		if (unlikely(!path))
@@ -1356,7 +1358,6 @@ repeat: 
			goto out;



		/* refill path */

		ext4_ext_drop_refs(path);

		path = ext4_ext_find_extent(inode,

				    (ext4_lblk_t)le32_to_cpu(newext->ee_block),

				    ppath, gb_flags);
@@ -1369,7 +1370,6 @@ repeat: 
			goto out;



		/* refill path */

		ext4_ext_drop_refs(path);

		path = ext4_ext_find_extent(inode,

				   (ext4_lblk_t)le32_to_cpu(newext->ee_block),

				    ppath, gb_flags);
@@ -3319,7 +3319,6 @@ static int ext4_split_extent(handle_t *handle, 
	 * Update path is required because previous ext4_split_extent_at() may

	 * result in split of original leaf or extent zeroout.

	 */

	ext4_ext_drop_refs(path);

	path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0);

	if (IS_ERR(path))

		return PTR_ERR(path);
@@ -3718,7 +3717,6 @@ static int ext4_convert_unwritten_extents_endio(handle_t *handle, 
						 EXT4_GET_BLOCKS_CONVERT);

		if (err < 0)

			return err;

		ext4_ext_drop_refs(path);

		path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0);

		if (IS_ERR(path))

			return PTR_ERR(path);
@@ -3947,7 +3945,6 @@ convert_initialized_extent(handle_t *handle, struct inode *inode, 
				EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);

		if (err < 0)

			return err;

		ext4_ext_drop_refs(path);

		path = ext4_ext_find_extent(inode, map->m_lblk, ppath, 0);

		if (IS_ERR(path))

			return PTR_ERR(path);

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