Implement .cleanup_rq() callback for freeing driver private part of the request. Then we can avoid to leak request private data 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 | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index e1da8c70a266..52537c145762 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -154,12 +154,9 @@ scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd) { - if (cmd->request->rq_flags & RQF_DONTPREP) { - cmd->request->rq_flags &= ~RQF_DONTPREP; - scsi_mq_uninit_cmd(cmd); - } else { - WARN_ON_ONCE(true); - } + WARN_ON_ONCE(!(cmd->request->rq_flags & RQF_DONTPREP)); + + scsi_mq_uninit_cmd(cmd); blk_mq_requeue_request(cmd->request, true); }
@@ -563,9 +560,13 @@ static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) { + if (!(cmd->request->rq_flags & RQF_DONTPREP)) + return; + scsi_mq_free_sgtables(cmd); scsi_uninit_cmd(cmd); scsi_del_cmd_from_list(cmd); + cmd->request->rq_flags &= ~RQF_DONTPREP; }
/* Returns false when no more bytes to process, true if there are more */ @@ -1089,6 +1090,17 @@ 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); + + scsi_mq_uninit_cmd(cmd); +} + /* Add a command to the list used by the aacraid and dpt_i2o drivers */ void scsi_add_cmd_to_list(struct scsi_cmnd *cmd) { @@ -1708,8 +1720,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, * we hit an error, as we will never see this command * again. */ - if (req->rq_flags & RQF_DONTPREP) - scsi_mq_uninit_cmd(cmd); + scsi_mq_uninit_cmd(cmd); break; } return ret; @@ -1816,6 +1827,7 @@ 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, };