Uses scsi_is_admin_queue() and scsi_get_scsi_dev() to retrieve
'scsi_device' for legacy path.
The same approach can be used in SCSI_MQ path too, just not very efficiently,
and will deal with that in the patch when introducing admin queue for SCSI_MQ.
Cc: Alan Stern <st...@rowland.harvard.edu>
Cc: Christoph Hellwig <h...@lst.de>
Cc: Bart Van Assche <bart.vanass...@wdc.com>
Cc: Jianchao Wang <jianchao.w.w...@oracle.com>
Cc: Hannes Reinecke <h...@suse.de>
Cc: Johannes Thumshirn <jthumsh...@suse.de>
Cc: Adrian Hunter <adrian.hun...@intel.com>
Cc: "James E.J. Bottomley" <j...@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.peter...@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Ming Lei <ming....@redhat.com>
---
drivers/scsi/scsi_lib.c | 37 +++++++++++++++++++++++++++++--------
1 file changed, 29 insertions(+), 8 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 2800dfae19cd..2f541b4fb32b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -46,6 +46,20 @@ static DEFINE_MUTEX(scsi_sense_cache_mutex);
static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd);
+/* For admin queue, its queuedata is NULL */
+static inline bool scsi_is_admin_queue(struct request_queue *q)
+{
+ return !q->queuedata;
+}
+
+/* This helper can only be used in req prep stage */
+static inline struct scsi_device *scsi_get_scsi_dev(struct request *rq)
+{
+ if (scsi_is_admin_queue(rq->q))
+ return scsi_req(rq)->sdev;
+ return rq->q->queuedata;
+}
+
static inline struct kmem_cache *
scsi_select_sense_cache(bool unchecked_isa_dma)
{
@@ -1426,10 +1440,9 @@ scsi_prep_state_check(struct scsi_device *sdev, struct
request *req)
}
static int
-scsi_prep_return(struct request_queue *q, struct request *req, int ret)
+scsi_prep_return(struct scsi_device *sdev, struct request_queue *q,
+ struct request *req, int ret)
{
- struct scsi_device *sdev = q->queuedata;
-
switch (ret) {
case BLKPREP_KILL:
case BLKPREP_INVALID:
@@ -1461,7 +1474,7 @@ scsi_prep_return(struct request_queue *q, struct request
*req, int ret)
static int scsi_prep_fn(struct request_queue *q, struct request *req)
{
- struct scsi_device *sdev = q->queuedata;
+ struct scsi_device *sdev = scsi_get_scsi_dev(req);
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
int ret;
@@ -1486,7 +1499,7 @@ static int scsi_prep_fn(struct request_queue *q, struct
request *req)
ret = scsi_setup_cmnd(sdev, req);
out:
- return scsi_prep_return(q, req, ret);
+ return scsi_prep_return(sdev, q, req, ret);
}
static void scsi_unprep_fn(struct request_queue *q, struct request *req)
@@ -1663,6 +1676,9 @@ static int scsi_lld_busy(struct request_queue *q)
if (blk_queue_dying(q))
return 0;
+ if (WARN_ON_ONCE(scsi_is_admin_queue(q)))
+ return 0;
+
shost = sdev->host;
/*
@@ -1866,7 +1882,7 @@ static void scsi_request_fn(struct request_queue *q)
__releases(q->queue_lock)
__acquires(q->queue_lock)
{
- struct scsi_device *sdev = q->queuedata;
+ struct scsi_device *sdev;
struct Scsi_Host *shost;
struct scsi_cmnd *cmd;
struct request *req;
@@ -1875,7 +1891,6 @@ static void scsi_request_fn(struct request_queue *q)
* To start with, we keep looping until the queue is empty, or until
* the host is no longer able to accept any more requests.
*/
- shost = sdev->host;
for (;;) {
int rtn;
/*
@@ -1887,6 +1902,10 @@ static void scsi_request_fn(struct request_queue *q)
if (!req)
break;
+ cmd = blk_mq_rq_to_pdu(req);
+ sdev = cmd->device;
+ shost = sdev->host;
+
if (unlikely(!scsi_device_online(sdev))) {
sdev_printk(KERN_ERR, sdev,
"rejecting I/O to offline device\n");
@@ -1904,7 +1923,6 @@ static void scsi_request_fn(struct request_queue *q)
blk_start_request(req);
spin_unlock_irq(q->queue_lock);
- cmd = blk_mq_rq_to_pdu(req);
if (cmd != req->special) {
printk(KERN_CRIT "impossible request in %s.\n"
"please mail a stack trace to "
@@ -2382,6 +2400,9 @@ struct scsi_device *scsi_device_from_queue(struct
request_queue *q)
{
struct scsi_device *sdev = NULL;
+ /* admin queue won't be exposed to external users */
+ WARN_ON_ONCE(scsi_is_admin_queue(q));
+
if (q->mq_ops) {
if (q->mq_ops == &scsi_mq_ops)
sdev = q->queuedata;
--
2.9.5
