DIO submission on underlying file may fail because of unaligned buffer or
start_sector & sector_length, fallback to buffered IO when that happens,
this way will make loop dio mode more reliable.
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
drivers/block/loop.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d1784f825b6b..fee78a640f75 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -590,6 +590,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0);
if (!cmd->use_dio) {
atomic_set(&cmd->ref, 1);
+buffered_io:
cmd->iocb.ki_flags = 0;
cmd->ret = lo_call_backing_rw_iter(file, &cmd->iocb, &iter, rw);
lo_rw_aio_do_completion(cmd);
@@ -603,8 +604,13 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
lo_rw_aio_do_completion(cmd);
- if (ret != -EIOCBQUEUED)
+ if (ret != -EIOCBQUEUED) {
+ if (ret < 0) {
+ cmd->use_dio = false;
+ goto buffered_io;
+ }
cmd->iocb.ki_complete(&cmd->iocb, ret, 0);
+ }
return 0;
}
--
2.31.1
