From eeee322647a67c20d9277c5e02c42b2126ea74bc Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Mon, 14 Feb 2011 15:55:33 -0500 Subject: [PATCH] NVMe: Handle failures differently in nvme_submit_bio_queue() Return -EBUSY if the queue is full or -ENOMEM if we failed to allocate memory (or map a scatterlist). Also use GFP_ATOMIC to allocate the nvme_bio and move the locking to the callers of nvme_submit_bio_queue(). In nvme_make_request(), don't permit an I/O to jump the queue -- if the congestion list already has an entry, just add to the tail, rather than trying to submit. Signed-off-by: Matthew Wilcox --- drivers/block/nvme.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c index c0e84b688f50..61a241741ca6 100644 --- a/drivers/block/nvme.c +++ b/drivers/block/nvme.c @@ -420,17 +420,17 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns, struct nvme_command *cmnd; struct nvme_bio *nbio; enum dma_data_direction dma_dir; - int cmdid; + int cmdid, result = -ENOMEM; u16 control; u32 dsmgmt; - unsigned long flags; int psegs = bio_phys_segments(ns->queue, bio); - nbio = alloc_nbio(psegs, GFP_NOIO); + nbio = alloc_nbio(psegs, GFP_ATOMIC); if (!nbio) - goto congestion; + goto nomem; nbio->bio = bio; + result = -EBUSY; cmdid = alloc_cmdid(nvmeq, nbio, bio_completion_id, IO_TIMEOUT); if (unlikely(cmdid < 0)) goto free_nbio; @@ -445,7 +445,6 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns, if (bio->bi_rw & REQ_RAHEAD) dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH; - spin_lock_irqsave(&nvmeq->q_lock, flags); cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail]; memset(cmnd, 0, sizeof(*cmnd)); @@ -457,8 +456,9 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns, dma_dir = DMA_FROM_DEVICE; } + result = -ENOMEM; if (nvme_map_bio(nvmeq->q_dmadev, nbio, bio, dma_dir, psegs) == 0) - goto mapping_failed; + goto free_nbio; cmnd->rw.flags = 1; cmnd->rw.command_id = cmdid; @@ -474,19 +474,12 @@ static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns, if (++nvmeq->sq_tail == nvmeq->q_depth) nvmeq->sq_tail = 0; - spin_unlock_irqrestore(&nvmeq->q_lock, flags); - - return 0; - - mapping_failed: - free_nbio(nvmeq, nbio); - bio_endio(bio, -ENOMEM); return 0; free_nbio: free_nbio(nvmeq, nbio); - congestion: - return -EBUSY; + nomem: + return result; } static void nvme_resubmit_bio(struct nvme_queue *nvmeq, struct bio *bio) @@ -507,13 +500,18 @@ static int nvme_make_request(struct request_queue *q, struct bio *bio) { struct nvme_ns *ns = q->queuedata; struct nvme_queue *nvmeq = get_nvmeq(ns); + int result = -EBUSY; - if (nvme_submit_bio_queue(nvmeq, ns, bio)) { - blk_set_queue_congested(q, rw_is_sync(bio->bi_rw)); - spin_lock_irq(&nvmeq->q_lock); + spin_lock_irq(&nvmeq->q_lock); + if (bio_list_empty(&nvmeq->sq_cong)) + result = nvme_submit_bio_queue(nvmeq, ns, bio); + if (unlikely(result)) { + if (bio_list_empty(&nvmeq->sq_cong)) + add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait); bio_list_add(&nvmeq->sq_cong, bio); - spin_unlock_irq(&nvmeq->q_lock); } + + spin_unlock_irq(&nvmeq->q_lock); put_nvmeq(nvmeq); return 0; -- 2.11.0