Add function to check if a SCSI command originates from the reserved
tag pool and update scsi_put_reserved_cmd() to only free commands if
they originate from the reserved tag pool.
Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
---
block/blk-mq.c | 15 +++++++++++++++
drivers/scsi/scsi_lib.c | 7 +++++--
include/linux/blk-mq.h | 1 +
include/scsi/scsi_cmnd.h | 13 +++++++++++++
4 files changed, 34 insertions(+), 2 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8e56884fd2e9..44482aaed11e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -604,6 +604,21 @@ static void __blk_mq_complete_request(struct request *rq)
put_cpu();
}
+/**
+ * blk_mq_rq_is_reserved - Check for reserved request
+ *
+ * @rq: Request to check
+ *
+ * Returns true if the request originates from the reserved tag pool.
+ */
+bool blk_mq_rq_is_reserved(struct request *rq)
+{
+ struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
+
+ return blk_mq_tag_is_reserved(hctx->tags, rq->tag);
+}
+EXPORT_SYMBOL_GPL(blk_mq_rq_is_reserved);
+
static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx)
__releases(hctx->srcu)
{
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d0972744ea7f..30f9ca9fce22 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1930,9 +1930,12 @@ EXPORT_SYMBOL_GPL(scsi_get_reserved_cmd);
*/
void scsi_put_reserved_cmd(struct scsi_cmnd *scmd)
{
- struct request *rq = blk_mq_rq_from_pdu(scmd);
+ struct request *rq;
- blk_mq_free_request(rq);
+ if (scmd && scsi_cmd_is_reserved(scmd)) {
+ rq = blk_mq_rq_from_pdu(scmd);
+ blk_mq_free_request(rq);
+ }
}
EXPORT_SYMBOL_GPL(scsi_put_reserved_cmd);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index f389d7c724bd..c186dc25fc1c 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -494,6 +494,7 @@ void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
void blk_mq_kick_requeue_list(struct request_queue *q);
void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
bool blk_mq_complete_request(struct request *rq);
+bool blk_mq_rq_is_reserved(struct request *rq);
bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list,
struct bio *bio, unsigned int nr_segs);
bool blk_mq_queue_stopped(struct request_queue *q);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 80ac89e47b47..2cd894fbdcfa 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -159,6 +159,19 @@ static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
}
+/**
+ * scsi_cmd_is_reserved - check for reserved scsi command
+ * @scmd: command to check
+ *
+ * Returns true if @scmd originates from the reserved tag pool.
+ */
+static inline bool scsi_cmd_is_reserved(struct scsi_cmnd *scmd)
+{
+ struct request *rq = blk_mq_rq_from_pdu(scmd);
+
+ return blk_mq_rq_is_reserved(rq);
+}
+
extern void scsi_finish_command(struct scsi_cmnd *cmd);
extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
--
2.16.4
