[PATCH] f2fs: flag as supporting buffered async reads

[Yangtao Li]

After enabling this feature, the read performance has been greatly
improved:

    167M/s -> 234M/s, Increase ratio by 40%

Test w/:
    ./fio --name=onessd --filename=/data/test/local/io_uring_test
    --size=256M --rw=randread --bs=4k --direct=0 --overwrite=0
    --numjobs=1 --iodepth=1 --time_based=0 --runtime=10
    --ioengine=io_uring --registerfiles --fixedbufs
    --gtod_reduce=1 --group_reporting --sqthread_poll=1

Signed-off-by: Lu Hongfei <luhongfei@xxxxxxxx>
Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
 fs/f2fs/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 015ed274dc31..23c68ee946e5 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -546,7 +546,7 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
 	if (err)
 		return err;
 
-	filp->f_mode |= FMODE_NOWAIT;
+	filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
 
 	return dquot_file_open(inode, filp);
 }
-- 
2.39.0