Taking a blktrace of a simple fio run on a block device file using
libaio and iodepth > 1 reveals that asynchronous writes are executed as
sync writes, that is, REQ_SYNC is set for the write BIOs.
Fix this by modifying dio_bio_write_op() to set REQ_SYNC only for IOs
that are indeed synchronous ones and set REQ_IDLE only for asynchronous
IOs.
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
---
block/fops.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/block/fops.c b/block/fops.c
index 50d245e8c913..5a4f57726828 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -34,7 +34,12 @@ static int blkdev_get_block(struct inode *inode, sector_t iblock,
static blk_opf_t dio_bio_write_op(struct kiocb *iocb)
{
- blk_opf_t opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
+ blk_opf_t opf = REQ_OP_WRITE;
+
+ if (is_sync_kiocb(iocb))
+ opf |= REQ_SYNC;
+ else
+ opf |= REQ_IDLE;
/* avoid the need for a I/O completion work item */
if (iocb_is_dsync(iocb))
--
2.38.1
