The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b7e9e1fb7a9227be34ad4a5e778022c3164494cf Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@xxxxxxxxxx>
Date: Thu, 25 Jul 2019 10:05:00 +0800
Subject: [PATCH] scsi: implement .cleanup_rq callback
Implement .cleanup_rq() callback for freeing driver private part
of the request. Then we can avoid to leak this part if the request isn't
completed by SCSI, and freed by blk-mq or upper layer(such as dm-rq) finally.
Cc: Ewan D. Milne <emilne@xxxxxxxxxx>
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Cc: dm-devel@xxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback")
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 11e64b50497f..4e88d7e9cf9a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1089,6 +1089,18 @@ static void scsi_initialize_rq(struct request *rq)
cmd->retries = 0;
}
+/*
+ * Only called when the request isn't completed by SCSI, and not freed by
+ * SCSI
+ */
+static void scsi_cleanup_rq(struct request *rq)
+{
+ if (rq->rq_flags & RQF_DONTPREP) {
+ scsi_mq_uninit_cmd(blk_mq_rq_to_pdu(rq));
+ rq->rq_flags &= ~RQF_DONTPREP;
+ }
+}
+
/* Add a command to the list used by the aacraid and dpt_i2o drivers */
void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
{
@@ -1821,6 +1833,7 @@ static const struct blk_mq_ops scsi_mq_ops = {
.init_request = scsi_mq_init_request,
.exit_request = scsi_mq_exit_request,
.initialize_rq_fn = scsi_initialize_rq,
+ .cleanup_rq = scsi_cleanup_rq,
.busy = scsi_mq_lld_busy,
.map_queues = scsi_map_queues,
};
