Hi all
This patch is submitted by Yunlei He originally, but it's not complete one,
so I modified it and add some description, then resubmit it.
>From 3f8de7fe93354215b9b12293302a0a999cf3888a Mon Sep 17 00:00:00 2001
From: Yunlei He <heyunlei@xxxxxxxxxx>
Date: Wed, 29 Jul 2015 15:10:24 +0800
Subject: [PATCH 2/4] f2fs: report EINVAL for unalignment direct IO
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@xxxxxxxxxx>
[Chao Yu make small change and add detail description in commit message]
Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
---
fs/f2fs/data.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 4fabdd4..7ea8eda 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1494,9 +1494,6 @@ static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
{
unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
- if (iov_iter_rw(iter) == READ)
- return 0;
-
if (offset & blocksize_mask)
return -EINVAL;
@@ -1525,8 +1522,9 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
return 0;
- if (check_direct_IO(inode, iter, offset))
- return 0;
+ err = check_direct_IO(inode, iter, offset);
+ if (err)
+ return err;
trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
--
2.4.2
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