From: Jan Kara Date: Thu, 27 Sep 2012 01:52:20 +0000 (-0400) Subject: ext4: fix fdatasync() for files with only i_size changes X-Git-Tag: v3.6.2~69 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=34414b2bf58b95110bf8ccef77d66c05de9e923c;p=thirdparty%2Fkernel%2Fstable.git ext4: fix fdatasync() for files with only i_size changes 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 Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index d0855c2a9c22a..475c211be3e08 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4055,6 +4055,7 @@ static int ext4_do_update_inode(handle_t *handle, 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; @@ -4105,7 +4106,10 @@ static int ext4_do_update_inode(handle_t *handle, 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, @@ -4158,7 +4162,7 @@ static int ext4_do_update_inode(handle_t *handle, 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);