[2/2] scsi: implement .cleanup_rq callback
diff mbox series

Message ID 20190718032519.28306-3-ming.lei@redhat.com
State New
Headers show
Series
  • block/scsi/dm-rq: fix leak of request private data in dm-mpath
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Commit Message

Ming Lei July 18, 2019, 3:25 a.m. UTC
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@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: <stable@vger.kernel.org>
Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/scsi/scsi_lib.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Patch
diff mbox series

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e1da8c70a266..59eee4605cda 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1089,6 +1089,20 @@  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)
+{
+	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
+
+	if (rq->rq_flags & RQF_DONTPREP) {
+		scsi_mq_uninit_cmd(cmd);
+		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)
 {
@@ -1816,6 +1830,7 @@  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,
 };