Just a straight forward conversion. The retry handling could potentially be done by blk-mq as well, but that's for another day.
Cc: Jeff Dike <[email protected]> Signed-off-by: Jens Axboe <[email protected]> --- arch/um/drivers/ubd_kern.c | 154 ++++++++++++++++++++++--------------- 1 file changed, 94 insertions(+), 60 deletions(-) diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 83c470364dfb..a302962a441d 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -22,7 +22,7 @@ #include <linux/module.h> #include <linux/init.h> -#include <linux/blkdev.h> +#include <linux/blk-mq.h> #include <linux/ata.h> #include <linux/hdreg.h> #include <linux/cdrom.h> @@ -156,6 +156,7 @@ struct ubd { struct cow cow; struct platform_device pdev; struct request_queue *queue; + struct blk_mq_tag_set tag_set; spinlock_t lock; struct scatterlist sg[MAX_SG]; struct request *request; @@ -436,7 +437,9 @@ __uml_help(udb_setup, " in the boot output.\n\n" ); -static void do_ubd_request(struct request_queue * q); +static void ubd_handle_request(struct ubd *dev); +static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd); /* Only changed by ubd_init, which is an initcall. */ static int thread_fd = -1; @@ -520,12 +523,12 @@ static void ubd_handler(void) return; } for (count = 0; count < n/sizeof(struct io_thread_req *); count++) { - blk_end_request( - (*irq_req_buffer)[count]->req, - BLK_STS_OK, - (*irq_req_buffer)[count]->length - ); - kfree((*irq_req_buffer)[count]); + struct io_thread_req *io_req = (*irq_req_buffer)[count]; + + if (!blk_update_request(io_req->req, BLK_STS_OK, io_req->length)) + __blk_mq_end_request(io_req->req, BLK_STS_OK); + + kfree(io_req); } } reactivate_fd(thread_fd, UBD_IRQ); @@ -534,7 +537,7 @@ static void ubd_handler(void) ubd = container_of(list, struct ubd, restart); list_del_init(&ubd->restart); spin_lock_irqsave(&ubd->lock, flags); - do_ubd_request(ubd->queue); + ubd_handle_request(ubd); spin_unlock_irqrestore(&ubd->lock, flags); } } @@ -856,6 +859,7 @@ static void ubd_device_release(struct device *dev) { struct ubd *ubd_dev = dev_get_drvdata(dev); + blk_mq_free_tag_set(&ubd_dev->tag_set); blk_cleanup_queue(ubd_dev->queue); *ubd_dev = ((struct ubd) DEFAULT_UBD); } @@ -897,20 +901,25 @@ static int ubd_disk_register(int major, u64 size, int unit, return 0; } +static const struct blk_mq_ops ubd_mq_ops = { + .queue_rq = ubd_queue_rq, +}; + #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) static int ubd_add(int n, char **error_out) { struct ubd *ubd_dev = &ubd_devs[n]; + struct blk_mq_tag_set *set; int err = 0; if(ubd_dev->file == NULL) - goto out; + goto out1; err = ubd_file_size(ubd_dev, &ubd_dev->size); if(err < 0){ *error_out = "Couldn't determine size of device's file"; - goto out; + goto out1; } ubd_dev->size = ROUND_BLOCK(ubd_dev->size); @@ -918,12 +927,26 @@ static int ubd_add(int n, char **error_out) INIT_LIST_HEAD(&ubd_dev->restart); sg_init_table(ubd_dev->sg, MAX_SG); - err = -ENOMEM; - ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock); - if (ubd_dev->queue == NULL) { + set = &ubd_dev->tag_set; + set->ops = &ubd_mq_ops; + set->nr_hw_queues = 1; + set->queue_depth = 2; + set->numa_node = NUMA_NO_NODE; + set->flags = BLK_MQ_F_SHOULD_MERGE; + err = blk_mq_alloc_tag_set(set); + if (err) { + *error_out = "Failed to initialize device tag set"; + goto out1; + } + + ubd_dev->queue = blk_mq_init_queue(set); + if (IS_ERR(ubd_dev->queue)) { + err = PTR_ERR(ubd_dev->queue); + ubd_dev->queue = NULL; *error_out = "Failed to initialize device queue"; goto out; } + ubd_dev->queue->queuedata = ubd_dev; blk_queue_write_cache(ubd_dev->queue, true, false); @@ -947,9 +970,12 @@ static int ubd_add(int n, char **error_out) err = 0; out: + blk_mq_free_tag_set(&ubd_dev->tag_set); +out1: return err; out_cleanup: + blk_mq_free_tag_set(&ubd_dev->tag_set); blk_cleanup_queue(ubd_dev->queue); goto out; } @@ -1338,10 +1364,11 @@ static bool submit_request(struct io_thread_req *io_req, struct ubd *dev) int n = os_write_file(thread_fd, &io_req, sizeof(io_req)); if (n != sizeof(io_req)) { - if (n != -EAGAIN) + if (n != -EAGAIN) { printk("write to io thread failed, " "errno = %d\n", -n); - else if (list_empty(&dev->restart)) + blk_mq_end_request(io_req->req, BLK_STS_IOERR); + } else if (list_empty(&dev->restart)) list_add(&dev->restart, &restart); kfree(io_req); @@ -1351,62 +1378,69 @@ static bool submit_request(struct io_thread_req *io_req, struct ubd *dev) } /* Called with dev->lock held */ -static void do_ubd_request(struct request_queue *q) +static void ubd_handle_request(struct ubd *dev) { + struct request *req = dev->request; struct io_thread_req *io_req; - struct request *req; - - while(1){ - struct ubd *dev = q->queuedata; - if(dev->request == NULL){ - struct request *req = blk_fetch_request(q); - if(req == NULL) - return; - dev->request = req; - dev->rq_pos = blk_rq_pos(req); - dev->start_sg = 0; - dev->end_sg = blk_rq_map_sg(q, req, dev->sg); + if (req_op(req) == REQ_OP_FLUSH) { + io_req = kmalloc(sizeof(struct io_thread_req), GFP_ATOMIC); + if (io_req == NULL) { + if (list_empty(&dev->restart)) + list_add(&dev->restart, &restart); + return; } + prepare_flush_request(req, io_req); + if (submit_request(io_req, dev) == false) + return; + } - req = dev->request; + while (dev->start_sg < dev->end_sg){ + struct scatterlist *sg = &dev->sg[dev->start_sg]; - if (req_op(req) == REQ_OP_FLUSH) { - io_req = kmalloc(sizeof(struct io_thread_req), - GFP_ATOMIC); - if (io_req == NULL) { - if (list_empty(&dev->restart)) - list_add(&dev->restart, &restart); - return; - } - prepare_flush_request(req, io_req); - if (submit_request(io_req, dev) == false) - return; + io_req = kmalloc(sizeof(struct io_thread_req), GFP_ATOMIC); + if (io_req == NULL){ + if (list_empty(&dev->restart)) + list_add(&dev->restart, &restart); + return; } + prepare_request(req, io_req, + (unsigned long long)dev->rq_pos << 9, + sg->offset, sg->length, sg_page(sg)); - while(dev->start_sg < dev->end_sg){ - struct scatterlist *sg = &dev->sg[dev->start_sg]; + if (submit_request(io_req, dev) == false) + return; - io_req = kmalloc(sizeof(struct io_thread_req), - GFP_ATOMIC); - if(io_req == NULL){ - if(list_empty(&dev->restart)) - list_add(&dev->restart, &restart); - return; - } - prepare_request(req, io_req, - (unsigned long long)dev->rq_pos << 9, - sg->offset, sg->length, sg_page(sg)); + dev->rq_pos += sg->length >> 9; + dev->start_sg++; + } - if (submit_request(io_req, dev) == false) - return; + dev->end_sg = 0; + dev->request = NULL; +} - dev->rq_pos += sg->length >> 9; - dev->start_sg++; - } - dev->end_sg = 0; - dev->request = NULL; +static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) +{ + struct ubd *dev = hctx->queue->queuedata; + struct request *req; + + spin_lock_irq(&dev->lock); + if (dev->request != NULL) { + spin_unlock_irq(&dev->lock); + return BLK_STS_DEV_RESOURCE; } + + req = bd->rq; + blk_mq_start_request(req); + dev->request = req; + dev->rq_pos = blk_rq_pos(req); + dev->start_sg = 0; + dev->end_sg = blk_rq_map_sg(req->q, req, dev->sg); + + ubd_handle_request(dev); + spin_unlock_irq(&dev->lock); + return BLK_STS_OK; } static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) -- 2.17.1
