sd/skd: stuff discard page in request->completion_data

Store the pointer to the page there, so we can always safely
reference it from end_io context where ->bio may have been
cleared.

Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 06d154d20faa..96af195224f2 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -737,6 +737,7 @@ static int sd_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)
                 goto out;
         }
 
+        rq->completion_data = page;
         blk_add_request_payload(rq, page, len);
         ret = scsi_setup_blk_pc_cmnd(sdp, rq);
         rq->__data_len = nr_bytes;
@@ -839,11 +840,9 @@ static void sd_unprep_fn(struct request_queue *q, struct request *rq)
 {
         struct scsi_cmnd *SCpnt = rq->special;
 
-        if (rq->cmd_flags & REQ_DISCARD) {
-                struct bio *bio = rq->bio;
+        if (rq->cmd_flags & REQ_DISCARD)
+                __free_page(rq->completion_data);
 
-                __free_page(bio->bi_io_vec->bv_page);
-        }
         if (SCpnt->cmnd != rq->cmd) {
                 mempool_free(SCpnt->cmnd, sd_cdb_pool);
                 SCpnt->cmnd = NULL;