f2fs doesn't support uncached write yet, for write() w/ IOCB_DONTCACHE
flag, let's return -EOPNOTSUPP instead of ignoring IOCB_DONTCACHE flag
and write w/o uncached IO.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Qi Han <hanqi@vivo.com>
Signed-off-by: Chao Yu <chao@kernel.org>
---
v2:
- fix author info
 fs/f2fs/file.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 9b8d24097b7a..7f09cad6b6d7 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -5185,6 +5185,11 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		goto out;
 	}
 
+	if (iocb->ki_flags & IOCB_DONTCACHE) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
 	if (!f2fs_is_compress_backend_ready(inode)) {
 		ret = -EOPNOTSUPP;
 		goto out;
-- 
2.49.0

On 8/5/25 12:19 AM, Chao Yu wrote:
> f2fs doesn't support uncached write yet, for write() w/ IOCB_DONTCACHE
> flag, let's return -EOPNOTSUPP instead of ignoring IOCB_DONTCACHE flag
> and write w/o uncached IO.

Didn't we agree that write support should be pursued first before
bifurcating the read/write DONTCACHE support?

-- 
Jens Axboe

On 8/5/25 23:37, Jens Axboe wrote:
> On 8/5/25 12:19 AM, Chao Yu wrote:
>> f2fs doesn't support uncached write yet, for write() w/ IOCB_DONTCACHE
>> flag, let's return -EOPNOTSUPP instead of ignoring IOCB_DONTCACHE flag
>> and write w/o uncached IO.
> 
> Didn't we agree that write support should be pursued first before
> bifurcating the read/write DONTCACHE support?

Yeah, no worries, this is just used for test purpose, will drop this once
Qi Han prepare the new patchset supporting dontcache in both read and write
path. :)

Thanks,