Re: [PATCH 1/2] ext4: Fix block zeroing when punching holes in indirect block files
From: Lukáš Czerner <hidden>
Date: 2014-06-19 15:38:36
On Wed, 18 Jun 2014, Jan Kara wrote:
Date: Wed, 18 Jun 2014 21:33:03 +0200
From: Jan Kara <jack@suse.cz>
To: Ted Tso <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org, Jan Kara <jack@suse.cz>
Subject: [PATCH 1/2] ext4: Fix block zeroing when punching holes in indirect
block files
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).Please see my patch [PATCH] ext4: Fix punch hole on files with indirect mapping which fixes those issues in a different way while also make this operation faster. Thanks! -Lukas
quoted hunk ↗ jump to hunk
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;