diff options
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 41 |
1 files changed, 39 insertions, 2 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index f23ec240cab0..0f81add6025e 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2734,6 +2734,39 @@ void sdev_evt_send_simple(struct scsi_device *sdev, EXPORT_SYMBOL_GPL(sdev_evt_send_simple); /** + * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn() + * @sdev: SCSI device to count the number of scsi_request_fn() callers for. + */ +static int scsi_request_fn_active(struct scsi_device *sdev) +{ + struct request_queue *q = sdev->request_queue; + int request_fn_active; + + WARN_ON_ONCE(sdev->host->use_blk_mq); + + spin_lock_irq(q->queue_lock); + request_fn_active = q->request_fn_active; + spin_unlock_irq(q->queue_lock); + + return request_fn_active; +} + +/** + * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls + * @sdev: SCSI device pointer. + * + * Wait until the ongoing shost->hostt->queuecommand() calls that are + * invoked from scsi_request_fn() have finished. + */ +static void scsi_wait_for_queuecommand(struct scsi_device *sdev) +{ + WARN_ON_ONCE(sdev->host->use_blk_mq); + + while (scsi_request_fn_active(sdev)) + msleep(20); +} + +/** * scsi_device_quiesce - Block user issued commands. * @sdev: scsi device to quiesce. * @@ -2817,8 +2850,7 @@ EXPORT_SYMBOL(scsi_target_resume); * @sdev: device to block * * Block request made by scsi lld's to temporarily stop all - * scsi commands on the specified device. Called from interrupt - * or normal process context. + * scsi commands on the specified device. May sleep. * * Returns zero if successful or error if not * @@ -2827,6 +2859,10 @@ EXPORT_SYMBOL(scsi_target_resume); * (which must be a legal transition). When the device is in this * state, all commands are deferred until the scsi lld reenables * the device with scsi_device_unblock or device_block_tmo fires. + * + * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after + * scsi_internal_device_block() has blocked a SCSI device and also + * remove the rport mutex lock and unlock calls from srp_queuecommand(). */ int scsi_internal_device_block(struct scsi_device *sdev) @@ -2854,6 +2890,7 @@ scsi_internal_device_block(struct scsi_device *sdev) spin_lock_irqsave(q->queue_lock, flags); blk_stop_queue(q); spin_unlock_irqrestore(q->queue_lock, flags); + scsi_wait_for_queuecommand(sdev); } return 0; |