We run ltp testcase with f2fs and obtain a TFAIL in diotest4, the result in
detail is as fallow:
dio04
<<<test_start>>>
tag=dio04 stime=1432278894
cmdline="diotest4"
contacts=""
analysis=exit
<<<test_output>>>
diotest4 1 TPASS : Negative Offset
diotest4 2 TPASS : removed
diotest4 3 TFAIL : diotest4.c:129: write allows odd count.returns 1: Success
diotest4 4 TFAIL : diotest4.c:183: Odd count of read and write
diotest4 5 TPASS : Read beyond the file size
......
the result of ext4 with same environment:
dio04
<<<test_start>>>
tag=dio04 stime=1432259643
cmdline="diotest4"
contacts=""
analysis=exit
<<<test_output>>>
diotest4 1 TPASS : Negative Offset
diotest4 2 TPASS : removed
diotest4 3 TPASS : Odd count of read and write
diotest4 4 TPASS : Read beyond the file size
......
The reason is that when triggering DIO in f2fs, we will return zero value
in ->direct_IO if writer's buffer offset, file offset and transfer size is
not alignment to block size of filesystem, resulting in falling back into
buffered write instead of returning -EINVAL.
This patch fixes that problem by returning correct error number for above
case, and removing the judgement condition in check_direct_IO to make sure
the verification will be enabled for direct reader too.
Besides, Jaegeuk Kim pointed out that there is expectional cases we should
always make direct-io falling back into buffered write, such as dio in
encrypted file.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
[Chao Yu make small change and add detail description in commit message]
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
c15e8599ff