ext4: honor O_(D)SYNC semantic in ext4_fallocate()
Ext4 must make sure the transaction to be commited to the disk when
user opens a file with O_(D)SYNC flag and do a fallocate(2) call.
This problem had been reported by Christoph Hellwig in this thread:
http://www.spinics.net/lists/linux-btrfs/msg13621.html
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 91341ec..f1089cb 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4420,6 +4420,8 @@
ext4_falloc_update_inode(inode, mode, new_size,
(map.m_flags & EXT4_MAP_NEW));
ext4_mark_inode_dirty(handle, inode);
+ if ((file->f_flags & O_SYNC) && ret >= max_blocks)
+ ext4_handle_sync(handle);
ret2 = ext4_journal_stop(handle);
if (ret2)
break;