From 523f431ccfffd3022e80e13befb9594f54b5607e Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 1 Sep 2014 14:38:09 -0400 Subject: [PATCH] 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: Theodore Ts'o --- fs/ext4/extents.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index ccdd2afc546e..4f4d52398712 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -867,8 +867,10 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, eh = ext_inode_hdr(inode); depth = ext_depth(inode); - /* account possible depth increase */ - if (!path) { + if (path) + ext4_ext_drop_refs(path); + else { + /* account possible depth increase */ 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); -- 2.20.1