[PATCH v3 05/11] scsi: scsi_debug: Use scsi_block_requests() to block queues

John Garry
2023-03-27T07:44:01Z

The feature to block queues is quite dubious, since it races with in-flight
IO. Indeed, it seems unnecessary for block queues for any times we do so.

Anyway, to keep the same behaviour, use standard SCSI API to stop IO being
sent - scsi_{un}block_requests().

Signed-off-by: John Garry <john.g.garry@oracle.com>
---
drivers/scsi/scsi_debug.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index cd05e2f87417..f53f3e78aaa1 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -359,7 +359,6 @@ struct sdebug_queue {
struct sdebug_queued_cmd qc_arr[SDEBUG_CANQUEUE];
unsigned long in_use_bm[SDEBUG_CANQUEUE_WORDS];
spinlock_t qc_lock;
- atomic_t blocked; /* to temporarily stop more being queued */
};

static atomic_t sdebug_cmnd_count; /* number of incoming commands */
@@ -5494,13 +5493,18 @@ static void sdebug_build_parts(unsigned char *ramp, unsigned long store_size)

static void block_unblock_all_queues(bool block)
{
- int j;
- struct sdebug_queue *sqp;
+ struct sdebug_host_info *sdhp;

lockdep_assert_held(&sdebug_host_list_mutex);

- for (j = 0, sqp = sdebug_q_arr; j < submit_queues; ++j, ++sqp)
- atomic_set(&sqp->blocked, (int)block);
+ list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
+ struct Scsi_Host *shost = sdhp->shost;
+
+ if (block)
+ scsi_block_requests(shost);
+ else
+ scsi_unblock_requests(shost);
+ }
}

/* Adjust (by rounding down) the sdebug_cmnd_count so abs(every_nth)-1
@@ -5572,10 +5576,6 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,

sqp = get_queue(cmnd);
spin_lock_irqsave(&sqp->qc_lock, iflags);
- if (unlikely(atomic_read(&sqp->blocked))) {
- spin_unlock_irqrestore(&sqp->qc_lock, iflags);
- return SCSI_MLQUEUE_HOST_BUSY;
- }

if (unlikely(sdebug_every_nth && (SDEBUG_OPT_RARE_TSF & sdebug_opts) &&
(scsi_result == 0))) {
--
2.35.3