[1/2] block: return errors from blk_execute_rq()

Commit Message

Keith Busch April 16, 2021, 4:53 p.m. UTC

The synchronous blk_execute_rq() had not provided a way for its callers
to know if its request was successful or not. Return the errno from the
completion status.

Reported-by: Yuanyuan Zhong <[e-mail]>
Signed-off-by: Keith Busch <[e-mail]>
---
 block/blk-exec.c       | 6 ++++--
 include/linux/blkdev.h | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

Comments

Chaitanya Kulkarni April 18, 2021, 4:13 a.m. UTC | #1

On 4/16/21 09:54, Keith Busch wrote:
> +extern int blk_execute_rq(struct gendisk *, struct request *, int);

I've not checked if it will work or not, but we have been dropping
the extern keywords for the new declarations and I'm not sure if that
applies here or not, so looks good to me.

Reviewed-by: Chaitanya Kulkarni <[e-mail]>

Patch

diff --git a/block/blk-exec.c b/block/blk-exec.c
index beae70a0e5e5..3877a2677dd4 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -21,7 +21,7 @@  static void blk_end_sync_rq(struct request *rq, blk_status_t error)
 {
 	struct completion *waiting = rq->end_io_data;
 
-	rq->end_io_data = NULL;
+	rq->end_io_data = ERR_PTR(blk_status_to_errno(error));
 
 	/*
 	 * complete last, if this is a stack request the process (and thus
@@ -72,8 +72,9 @@  EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
  * Description:
  *    Insert a fully prepared request at the back of the I/O scheduler queue
  *    for execution and wait for completion.
+ * Return: The errno value of the blk_status_t provided to blk_mq_end_request().
  */
-void blk_execute_rq(struct gendisk *bd_disk, struct request *rq, int at_head)
+int blk_execute_rq(struct gendisk *bd_disk, struct request *rq, int at_head)
 {
 	DECLARE_COMPLETION_ONSTACK(wait);
 	unsigned long hang_check;
@@ -87,5 +88,6 @@  void blk_execute_rq(struct gendisk *bd_disk, struct request *rq, int at_head)
 		while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2)));
 	else
 		wait_for_completion_io(&wait);
+	return PTR_ERR_OR_ZERO(rq->end_io_data);
 }
 EXPORT_SYMBOL(blk_execute_rq);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index b91ba6207365..15e4ffac33af 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -938,7 +938,7 @@  extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, uns
 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 			       struct rq_map_data *, const struct iov_iter *,
 			       gfp_t);
-extern void blk_execute_rq(struct gendisk *, struct request *, int);
+extern int blk_execute_rq(struct gendisk *, struct request *, int);
 extern void blk_execute_rq_nowait(struct gendisk *,
 				  struct request *, int, rq_end_io_fn *);