| From b71fc079b5d8f42b2a52743c8d2f1d35d655b1c5 Mon Sep 17 00:00:00 2001 |
| From: Jan Kara <jack@suse.cz> |
| Date: Wed, 26 Sep 2012 21:52:20 -0400 |
| Subject: ext4: fix fdatasync() for files with only i_size changes |
| |
| From: Jan Kara <jack@suse.cz> |
| |
| commit b71fc079b5d8f42b2a52743c8d2f1d35d655b1c5 upstream. |
| |
| 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. |
| |
| Reported-by: Kristian Nielsen <knielsen@knielsen-hq.org> |
| Signed-off-by: Jan Kara <jack@suse.cz> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/ext4/inode.c | 8 ++++++-- |
| 1 file changed, 6 insertions(+), 2 deletions(-) |
| |
| --- a/fs/ext4/inode.c |
| +++ b/fs/ext4/inode.c |
| @@ -3892,6 +3892,7 @@ static int ext4_do_update_inode(handle_t |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| struct buffer_head *bh = iloc->bh; |
| int err = 0, rc, block; |
| + int need_datasync = 0; |
| |
| /* For fields not not tracking in the in-memory inode, |
| * initialise them to zero for new inodes. */ |
| @@ -3940,7 +3941,10 @@ static int ext4_do_update_inode(handle_t |
| 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, |
| @@ -3991,7 +3995,7 @@ static int ext4_do_update_inode(handle_t |
| 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); |
