Re: [PATCH] block: handle partial completions for special payload requests

[Jens Axboe]

On 05/11/2017 04:34 AM, Christoph Hellwig wrote:
> SCSI devices can return short writes on Write Same just like for normal
> writes, so we need to handle this case for our special payload requests
> as well.

Added for 4.12-rc1, thanks Christoph.

-- 
Jens Axboe

[PATCH] block: handle partial completions for special payload requests

[Christoph Hellwig]

SCSI devices can return short writes on Write Same just like for normal
writes, so we need to handle this case for our special payload requests
as well.

Signed-off-by: Christoph Hellwig 
Reported-by: Abdul Haleem 
Tested-by: Abdul Haleem 
---
 block/blk-core.c | 24 
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index c580b0138a7f..c7068520794b 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2644,8 +2644,6 @@ bool blk_update_request(struct request *req, int error, 
unsigned int nr_bytes)
return false;
}
 
-   WARN_ON_ONCE(req->rq_flags & RQF_SPECIAL_PAYLOAD);
-
req->__data_len -= total_bytes;
 
/* update sector only for requests with clear definition of sector */
@@ -2658,17 +2656,19 @@ bool blk_update_request(struct request *req, int error, 
unsigned int nr_bytes)
req->cmd_flags |= req->bio->bi_opf & REQ_FAILFAST_MASK;
}
 
-   /*
-* If total number of sectors is less than the first segment
-* size, something has gone terribly wrong.
-*/
-   if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) {
-   blk_dump_rq_flags(req, "request botched");
-   req->__data_len = blk_rq_cur_bytes(req);
-   }
+   if (!(req->rq_flags & RQF_SPECIAL_PAYLOAD)) {
+   /*
+* If total number of sectors is less than the first segment
+* size, something has gone terribly wrong.
+*/
+   if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) {
+   blk_dump_rq_flags(req, "request botched");
+   req->__data_len = blk_rq_cur_bytes(req);
+   }
 
-   /* recalculate the number of segments */
-   blk_recalc_rq_segments(req);
+   /* recalculate the number of segments */
+   blk_recalc_rq_segments(req);
+   }
 
return true;
 }
-- 
2.11.0