From: Jens Axboe Date: Thu, 30 Mar 2017 19:44:26 +0000 (-0600) Subject: null_blk: add blocking mode X-Git-Tag: Ubuntu-5.10.0-12.13~10468^2~229 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=db5bcf87bb9e856e90c131d6e636a5550c2bbcd3;p=mirror_ubuntu-hirsute-kernel.git null_blk: add blocking mode This adds a new module parameter to null_blk, blocking. If set, null_blk will set the BLK_MQ_F_BLOCKING flag, indicating that it sometimes/always needs to block in its ->queue_rq() function. The intent is to help find regressions in blocking drivers, since not many of them exist. If null_blk is loaded with submit_queues > 1 and blocking=1, this shows the regression recently fixed by bf4907c05e61. Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe --- diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 6f2e565bccc5..444f8d88f1a8 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -117,6 +117,10 @@ static bool use_lightnvm; module_param(use_lightnvm, bool, S_IRUGO); MODULE_PARM_DESC(use_lightnvm, "Register as a LightNVM device"); +static bool blocking; +module_param(blocking, bool, S_IRUGO); +MODULE_PARM_DESC(blocking, "Register as a blocking blk-mq driver device"); + static int irqmode = NULL_IRQ_SOFTIRQ; static int null_set_irqmode(const char *str, const struct kernel_param *kp) @@ -357,6 +361,8 @@ static int null_queue_rq(struct blk_mq_hw_ctx *hctx, { struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); + might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); + if (irqmode == NULL_IRQ_TIMER) { hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); cmd->timer.function = null_cmd_timer_expired; @@ -724,6 +730,9 @@ static int null_add_dev(void) nullb->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; nullb->tag_set.driver_data = nullb; + if (blocking) + nullb->tag_set.flags |= BLK_MQ_F_BLOCKING; + rv = blk_mq_alloc_tag_set(&nullb->tag_set); if (rv) goto out_cleanup_queues;