ext4: fix incorect journal credits reservation in ext4_zero_range

Currently we reserve only 4 blocks but in worst case scenario
ext4_zero_partial_blocks() may want to zeroout and convert two
non adjacent blocks.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
This commit is contained in:
Dmitry Monakhov 2014-08-27 18:33:49 -04:00 committed by Theodore Ts'o
parent 4631dbf677
commit 69dc953640

View File

@ -4731,6 +4731,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
loff_t new_size = 0;
int ret = 0;
int flags;
int credits;
int partial;
loff_t start, end;
ext4_lblk_t lblk;
@ -4830,8 +4831,14 @@ static long ext4_zero_range(struct file *file, loff_t offset,
if (ret)
goto out_dio;
}
handle = ext4_journal_start(inode, EXT4_HT_MISC, 4);
/*
* In worst case we have to writeout two nonadjacent unwritten
* blocks and update the inode
*/
credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
if (ext4_should_journal_data(inode))
credits += 2;
handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
ext4_std_error(inode->i_sb, ret);