[PATCH 16/27] ext4: don't order data for inode with EXT4_STATE_BUFFERED_IOMAP

[Zhang Yi <yi.zhang@huaweicloud.com>]

From: Zhang Yi <yi.zhang@huawei.com>

In the iomap buffered I/O path, there is no risk of exposing stale data
because we always allocate unwritten extents for new allocated blocks,
the extent changes to written only when the I/O is completed. Therefore,
we do not need to order data in this mode.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/ext4_jbd2.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index 0c77697d5e90..9dca10027032 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -467,6 +467,14 @@ static inline int ext4_should_journal_data(struct inode *inode)
 
 static inline int ext4_should_order_data(struct inode *inode)
 {
+	/*
+	 * There is no need to order data for inodes with iomap buffered I/O
+	 * path since it always allocate unwritten extents for new allocated
+	 * blocks and have no risk of stale data.
+	 */
+	if (ext4_test_inode_state(inode, EXT4_STATE_BUFFERED_IOMAP))
+		return 0;
+
 	return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
 }
 
-- 
2.46.1