[PATCH v6 5/8] scsi: core: Rework scsi_single_lun_run()

Bart Van Assche
2022-09-29T22:46:10Z

Use __starget_for_each_device() instead of open-coding
starget_for_each_device(). This patch removes code that calls
scsi_device_put() from atomic context.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/scsi/scsi_lib.c | 32 +++++++++++++++-----------------
1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 473d9403f0c1..da1e6f9f9221 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -302,6 +302,18 @@ static void scsi_kick_queue(struct request_queue *q)
blk_mq_run_hw_queues(q, false);
}

+/*
+ * Kick the queue of SCSI device @sdev if @sdev != current_sdev. Called with
+ * interrupts disabled.
+ */
+static void scsi_kick_sdev_queue(struct scsi_device *sdev, void *data)
+{
+ struct scsi_device *current_sdev = data;
+
+ if (sdev != current_sdev)
+ blk_mq_run_hw_queues(sdev->request_queue, true);
+}
+
/*
* Called for single_lun devices on IO completion. Clear starget_sdev_user,
* and call blk_run_queue for all the scsi_devices on the target -
@@ -312,7 +324,6 @@ static void scsi_kick_queue(struct request_queue *q)
static void scsi_single_lun_run(struct scsi_device *current_sdev)
{
struct Scsi_Host *shost = current_sdev->host;
- struct scsi_device *sdev, *tmp;
struct scsi_target *starget = scsi_target(current_sdev);
unsigned long flags;

@@ -329,22 +340,9 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev)
scsi_kick_queue(current_sdev->request_queue);

spin_lock_irqsave(shost->host_lock, flags);
- if (starget->starget_sdev_user)
- goto out;
- list_for_each_entry_safe(sdev, tmp, &starget->devices,
- same_target_siblings) {
- if (sdev == current_sdev)
- continue;
- if (scsi_device_get(sdev))
- continue;
-
- spin_unlock_irqrestore(shost->host_lock, flags);
- scsi_kick_queue(sdev->request_queue);
- spin_lock_irqsave(shost->host_lock, flags);
-
- scsi_device_put(sdev);
- }
- out:
+ if (!starget->starget_sdev_user)
+ __starget_for_each_device(starget, current_sdev,
+ scsi_kick_sdev_queue);
spin_unlock_irqrestore(shost->host_lock, flags);
}