在 2024/8/15 19:27, alexjlzheng@xxxxxxxxx 写道:
From: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
The commit 91562895f803 ("ext4: properly sync file size update after O_SYNC
direct IO") causes confusion about the meaning of the return value of
ext4_dio_write_end_io().
Specifically, when the ext4_handle_inode_extension() operation succeeds,
ext4_dio_write_end_io() directly returns count instead of 0.
This does not cause a bug in the current kernel, but the semantics of the
return value of the ext4_dio_write_end_io() function are wrong, which is
likely to introduce bugs in the future code evolution.
Signed-off-by: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
---
fs/ext4/file.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index c89e434db6b7..6df5a92cec2b 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -392,8 +392,9 @@ static int ext4_dio_write_end_io(struct kiocb *iocb, ssize_t size,
*/
if (pos + size <= READ_ONCE(EXT4_I(inode)->i_disksize) &&
pos + size <= i_size_read(inode))
- return size;
- return ext4_handle_inode_extension(inode, pos, size);
+ return 0;
+ error = ext4_handle_inode_extension(inode, pos, size);
+ return error < 0 ? error : 0;
Why?
iomap_dio_complete can use the return value directly without any bug.
And I think the code now seems more clearly...
}
static const struct iomap_dio_ops ext4_dio_write_ops = {
