[PATCH v4 06/21] ext2: Fix lost inode updates for IS_SYNC inodes

[Jan Kara <jack@suse.cz>]

ext2_setsize() and ext2_xattr_set2() had a construct like:

	if (IS_SYNC(inode)) {
		sync_inode_metadata(inode, 1);
	} else {
		mark_inode_dirty(inode);
	}

which leads to lost inode updates for IS_SYNC inodes because
sync_inode_metadata() does anything only if the inode is already dirty
and hence inode updates may be simply lost. Fix the problem by
unconditionally marking the inode dirty and *then* call
sync_inode_metadata().

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext2/inode.c | 7 ++-----
 fs/ext2/xattr.c | 4 ++--
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 29808629cce5..269b1c9fba5f 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1258,12 +1258,9 @@ static int ext2_setsize(struct inode *inode, loff_t newsize)
 	filemap_invalidate_unlock(inode->i_mapping);
 
 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
-	if (inode_needs_sync(inode)) {
-		mmb_sync(&EXT2_I(inode)->i_metadata_bhs);
+	mark_inode_dirty(inode);
+	if (inode_needs_sync(inode))
 		sync_inode_metadata(inode, 1);
-	} else {
-		mark_inode_dirty(inode);
-	}
 
 	return 0;
 }
diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index e55d16abf422..be63f89402a3 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -777,6 +777,7 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
 	/* Update the inode. */
 	EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
 	inode_set_ctime_current(inode);
+	mark_inode_dirty(inode);
 	if (IS_SYNC(inode)) {
 		error = sync_inode_metadata(inode, 1);
 		/* In case sync failed due to ENOSPC the inode was actually
@@ -789,8 +790,7 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
 			}
 			goto cleanup;
 		}
-	} else
-		mark_inode_dirty(inode);
+	}
 
 	error = 0;
 	if (old_bh && old_bh != new_bh) {
-- 
2.51.0