ext4: fix fdatasync() for files with only i_size changes
Code tracking when transaction needs to be committed on fdatasync(2) forgets
to handle a situation when only inode's i_size is changed. Thus in such
situations fdatasync(2) doesn't force transaction with new i_size to disk
and that can result in wrong i_size after a crash.
Fix the issue by updating inode's i_datasync_tid whenever its size is
updated.
CC: <stable@vger.kernel.org> # >= 2.6.32
Reported-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 0a31197..4df5e95 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4054,6 +4054,7 @@
struct ext4_inode_info *ei = EXT4_I(inode);
struct buffer_head *bh = iloc->bh;
int err = 0, rc, block;
+ int need_datasync = 0;
uid_t i_uid;
gid_t i_gid;
@@ -4104,7 +4105,10 @@
raw_inode->i_file_acl_high =
cpu_to_le16(ei->i_file_acl >> 32);
raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
- ext4_isize_set(raw_inode, ei->i_disksize);
+ if (ei->i_disksize != ext4_isize(raw_inode)) {
+ ext4_isize_set(raw_inode, ei->i_disksize);
+ need_datasync = 1;
+ }
if (ei->i_disksize > 0x7fffffffULL) {
struct super_block *sb = inode->i_sb;
if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
@@ -4157,7 +4161,7 @@
err = rc;
ext4_clear_inode_state(inode, EXT4_STATE_NEW);
- ext4_update_inode_fsync_trans(handle, inode, 0);
+ ext4_update_inode_fsync_trans(handle, inode, need_datasync);
out_brelse:
brelse(bh);
ext4_std_error(inode->i_sb, err);