[PATCH 1/2] ext4: Fix block zeroing when punching holes in indirect block files

Jan Kara
2014-10-10T14:24:09Z

free_holes_block() passed local variable as a block pointer
to ext4_clear_blocks(). Thus ext4_clear_blocks() zeroed out this local
variable instead of proper place in inode / indirect block. We later
zero out proper place in inode / indirect block but don't dirty the
inode / buffer again which can lead to subtle issues (some changes e.g.
to inode can be lost).

Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/indirect.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index 8a57e9fcd1b9..9d381707a6fc 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -1329,8 +1329,8 @@ static int free_hole_blocks(handle_t *handle, struct inode *inode,
if (level == 0 ||
(bh && all_zeroes((__le32 *)bh->b_data,
(__le32 *)bh->b_data + addr_per_block))) {
- ext4_free_data(handle, inode, parent_bh, &blk, &blk+1);
- *i_data = 0;
+ ext4_free_data(handle, inode, parent_bh,
+ i_data, i_data + 1);
}
brelse(bh);
bh = NULL;