diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-07 16:04:56 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-07 16:04:56 +0400 |
commit | dc92b1f9ab1e1665dbbc56911782358e7f9a49f9 (patch) | |
tree | 965ccb4a0f2c24a8b24adce415f6506246d07a90 /drivers/block | |
parent | 5e090ed7af10729a396a25df43d69a236e789736 (diff) | |
parent | ca16f580a5db7e60bfafe59a50bb133bd3347491 (diff) | |
download | linux-dc92b1f9ab1e1665dbbc56911782358e7f9a49f9.tar.xz |
Merge branch 'virtio-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio changes from Rusty Russell:
"New workflow: same git trees pulled by linux-next get sent straight to
Linus. Git is awkward at shuffling patches compared with quilt or mq,
but that doesn't happen often once things get into my -next branch."
* 'virtio-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (24 commits)
lguest: fix occasional crash in example launcher.
virtio-blk: Disable callback in virtblk_done()
virtio_mmio: Don't attempt to create empty virtqueues
virtio_mmio: fix off by one error allocating queue
drivers/virtio/virtio_pci.c: fix error return code
virtio: don't crash when device is buggy
virtio: remove CONFIG_VIRTIO_RING
virtio: add help to CONFIG_VIRTIO option.
virtio: support reserved vqs
virtio: introduce an API to set affinity for a virtqueue
virtio-ring: move queue_index to vring_virtqueue
virtio_balloon: not EXPERIMENTAL any more.
virtio-balloon: dependency fix
virtio-blk: fix NULL checking in virtblk_alloc_req()
virtio-blk: Add REQ_FLUSH and REQ_FUA support to bio path
virtio-blk: Add bio-based IO path for virtio-blk
virtio: console: fix error handling in init() function
tools: Fix pthread flag for Makefile of trace-agent used by virtio-trace
tools: Add guest trace agent as a user tool
virtio/console: Allocate scatterlist according to the current pipe size
...
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/virtio_blk.c | 306 |
1 files changed, 269 insertions, 37 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index c0bbeb470754..0bdde8fba397 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -14,6 +14,9 @@ #define PART_BITS 4 +static bool use_bio; +module_param(use_bio, bool, S_IRUGO); + static int major; static DEFINE_IDA(vd_index_ida); @@ -23,6 +26,7 @@ struct virtio_blk { struct virtio_device *vdev; struct virtqueue *vq; + wait_queue_head_t queue_wait; /* The disk structure for the kernel. */ struct gendisk *disk; @@ -51,53 +55,244 @@ struct virtio_blk struct virtblk_req { struct request *req; + struct bio *bio; struct virtio_blk_outhdr out_hdr; struct virtio_scsi_inhdr in_hdr; + struct work_struct work; + struct virtio_blk *vblk; + int flags; u8 status; + struct scatterlist sg[]; +}; + +enum { + VBLK_IS_FLUSH = 1, + VBLK_REQ_FLUSH = 2, + VBLK_REQ_DATA = 4, + VBLK_REQ_FUA = 8, }; -static void blk_done(struct virtqueue *vq) +static inline int virtblk_result(struct virtblk_req *vbr) +{ + switch (vbr->status) { + case VIRTIO_BLK_S_OK: + return 0; + case VIRTIO_BLK_S_UNSUPP: + return -ENOTTY; + default: + return -EIO; + } +} + +static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk, + gfp_t gfp_mask) { - struct virtio_blk *vblk = vq->vdev->priv; struct virtblk_req *vbr; - unsigned int len; - unsigned long flags; - spin_lock_irqsave(vblk->disk->queue->queue_lock, flags); - while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) { - int error; + vbr = mempool_alloc(vblk->pool, gfp_mask); + if (!vbr) + return NULL; - switch (vbr->status) { - case VIRTIO_BLK_S_OK: - error = 0; - break; - case VIRTIO_BLK_S_UNSUPP: - error = -ENOTTY; - break; - default: - error = -EIO; + vbr->vblk = vblk; + if (use_bio) + sg_init_table(vbr->sg, vblk->sg_elems); + + return vbr; +} + +static void virtblk_add_buf_wait(struct virtio_blk *vblk, + struct virtblk_req *vbr, + unsigned long out, + unsigned long in) +{ + DEFINE_WAIT(wait); + + for (;;) { + prepare_to_wait_exclusive(&vblk->queue_wait, &wait, + TASK_UNINTERRUPTIBLE); + + spin_lock_irq(vblk->disk->queue->queue_lock); + if (virtqueue_add_buf(vblk->vq, vbr->sg, out, in, vbr, + GFP_ATOMIC) < 0) { + spin_unlock_irq(vblk->disk->queue->queue_lock); + io_schedule(); + } else { + virtqueue_kick(vblk->vq); + spin_unlock_irq(vblk->disk->queue->queue_lock); break; } - switch (vbr->req->cmd_type) { - case REQ_TYPE_BLOCK_PC: - vbr->req->resid_len = vbr->in_hdr.residual; - vbr->req->sense_len = vbr->in_hdr.sense_len; - vbr->req->errors = vbr->in_hdr.errors; - break; - case REQ_TYPE_SPECIAL: - vbr->req->errors = (error != 0); - break; - default: - break; + } + + finish_wait(&vblk->queue_wait, &wait); +} + +static inline void virtblk_add_req(struct virtblk_req *vbr, + unsigned int out, unsigned int in) +{ + struct virtio_blk *vblk = vbr->vblk; + + spin_lock_irq(vblk->disk->queue->queue_lock); + if (unlikely(virtqueue_add_buf(vblk->vq, vbr->sg, out, in, vbr, + GFP_ATOMIC) < 0)) { + spin_unlock_irq(vblk->disk->queue->queue_lock); + virtblk_add_buf_wait(vblk, vbr, out, in); + return; + } + virtqueue_kick(vblk->vq); + spin_unlock_irq(vblk->disk->queue->queue_lock); +} + +static int virtblk_bio_send_flush(struct virtblk_req *vbr) +{ + unsigned int out = 0, in = 0; + + vbr->flags |= VBLK_IS_FLUSH; + vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH; + vbr->out_hdr.sector = 0; + vbr->out_hdr.ioprio = 0; + sg_set_buf(&vbr->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); + sg_set_buf(&vbr->sg[out + in++], &vbr->status, sizeof(vbr->status)); + + virtblk_add_req(vbr, out, in); + + return 0; +} + +static int virtblk_bio_send_data(struct virtblk_req *vbr) +{ + struct virtio_blk *vblk = vbr->vblk; + unsigned int num, out = 0, in = 0; + struct bio *bio = vbr->bio; + + vbr->flags &= ~VBLK_IS_FLUSH; + vbr->out_hdr.type = 0; + vbr->out_hdr.sector = bio->bi_sector; + vbr->out_hdr.ioprio = bio_prio(bio); + + sg_set_buf(&vbr->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); + + num = blk_bio_map_sg(vblk->disk->queue, bio, vbr->sg + out); + + sg_set_buf(&vbr->sg[num + out + in++], &vbr->status, + sizeof(vbr->status)); + + if (num) { + if (bio->bi_rw & REQ_WRITE) { + vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; + out += num; + } else { + vbr->out_hdr.type |= VIRTIO_BLK_T_IN; + in += num; } + } + + virtblk_add_req(vbr, out, in); + + return 0; +} + +static void virtblk_bio_send_data_work(struct work_struct *work) +{ + struct virtblk_req *vbr; + + vbr = container_of(work, struct virtblk_req, work); + + virtblk_bio_send_data(vbr); +} + +static void virtblk_bio_send_flush_work(struct work_struct *work) +{ + struct virtblk_req *vbr; + + vbr = container_of(work, struct virtblk_req, work); + + virtblk_bio_send_flush(vbr); +} + +static inline void virtblk_request_done(struct virtblk_req *vbr) +{ + struct virtio_blk *vblk = vbr->vblk; + struct request *req = vbr->req; + int error = virtblk_result(vbr); + + if (req->cmd_type == REQ_TYPE_BLOCK_PC) { + req->resid_len = vbr->in_hdr.residual; + req->sense_len = vbr->in_hdr.sense_len; + req->errors = vbr->in_hdr.errors; + } else if (req->cmd_type == REQ_TYPE_SPECIAL) { + req->errors = (error != 0); + } + + __blk_end_request_all(req, error); + mempool_free(vbr, vblk->pool); +} + +static inline void virtblk_bio_flush_done(struct virtblk_req *vbr) +{ + struct virtio_blk *vblk = vbr->vblk; + + if (vbr->flags & VBLK_REQ_DATA) { + /* Send out the actual write data */ + INIT_WORK(&vbr->work, virtblk_bio_send_data_work); + queue_work(virtblk_wq, &vbr->work); + } else { + bio_endio(vbr->bio, virtblk_result(vbr)); + mempool_free(vbr, vblk->pool); + } +} + +static inline void virtblk_bio_data_done(struct virtblk_req *vbr) +{ + struct virtio_blk *vblk = vbr->vblk; - __blk_end_request_all(vbr->req, error); + if (unlikely(vbr->flags & VBLK_REQ_FUA)) { + /* Send out a flush before end the bio */ + vbr->flags &= ~VBLK_REQ_DATA; + INIT_WORK(&vbr->work, virtblk_bio_send_flush_work); + queue_work(virtblk_wq, &vbr->work); + } else { + bio_endio(vbr->bio, virtblk_result(vbr)); mempool_free(vbr, vblk->pool); } +} + +static inline void virtblk_bio_done(struct virtblk_req *vbr) +{ + if (unlikely(vbr->flags & VBLK_IS_FLUSH)) + virtblk_bio_flush_done(vbr); + else + virtblk_bio_data_done(vbr); +} + +static void virtblk_done(struct virtqueue *vq) +{ + struct virtio_blk *vblk = vq->vdev->priv; + bool bio_done = false, req_done = false; + struct virtblk_req *vbr; + unsigned long flags; + unsigned int len; + + spin_lock_irqsave(vblk->disk->queue->queue_lock, flags); + do { + virtqueue_disable_cb(vq); + while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) { + if (vbr->bio) { + virtblk_bio_done(vbr); + bio_done = true; + } else { + virtblk_request_done(vbr); + req_done = true; + } + } + } while (!virtqueue_enable_cb(vq)); /* In case queue is stopped waiting for more buffers. */ - blk_start_queue(vblk->disk->queue); + if (req_done) + blk_start_queue(vblk->disk->queue); spin_unlock_irqrestore(vblk->disk->queue->queue_lock, flags); + + if (bio_done) + wake_up(&vblk->queue_wait); } static bool do_req(struct request_queue *q, struct virtio_blk *vblk, @@ -106,13 +301,13 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, unsigned long num, out = 0, in = 0; struct virtblk_req *vbr; - vbr = mempool_alloc(vblk->pool, GFP_ATOMIC); + vbr = virtblk_alloc_req(vblk, GFP_ATOMIC); if (!vbr) /* When another request finishes we'll try again. */ return false; vbr->req = req; - + vbr->bio = NULL; if (req->cmd_flags & REQ_FLUSH) { vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH; vbr->out_hdr.sector = 0; @@ -172,7 +367,8 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, } } - if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr, GFP_ATOMIC)<0) { + if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr, + GFP_ATOMIC) < 0) { mempool_free(vbr, vblk->pool); return false; } @@ -180,7 +376,7 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, return true; } -static void do_virtblk_request(struct request_queue *q) +static void virtblk_request(struct request_queue *q) { struct virtio_blk *vblk = q->queuedata; struct request *req; @@ -203,6 +399,34 @@ static void do_virtblk_request(struct request_queue *q) virtqueue_kick(vblk->vq); } +static void virtblk_make_request(struct request_queue *q, struct bio *bio) +{ + struct virtio_blk *vblk = q->queuedata; + struct virtblk_req *vbr; + + BUG_ON(bio->bi_phys_segments + 2 > vblk->sg_elems); + + vbr = virtblk_alloc_req(vblk, GFP_NOIO); + if (!vbr) { + bio_endio(bio, -ENOMEM); + return; + } + + vbr->bio = bio; + vbr->flags = 0; + if (bio->bi_rw & REQ_FLUSH) + vbr->flags |= VBLK_REQ_FLUSH; + if (bio->bi_rw & REQ_FUA) + vbr->flags |= VBLK_REQ_FUA; + if (bio->bi_size) + vbr->flags |= VBLK_REQ_DATA; + + if (unlikely(vbr->flags & VBLK_REQ_FLUSH)) + virtblk_bio_send_flush(vbr); + else + virtblk_bio_send_data(vbr); +} + /* return id (s/n) string for *disk to *id_str */ static int virtblk_get_id(struct gendisk *disk, char *id_str) @@ -360,7 +584,7 @@ static int init_vq(struct virtio_blk *vblk) int err = 0; /* We expect one virtqueue, for output. */ - vblk->vq = virtio_find_single_vq(vblk->vdev, blk_done, "requests"); + vblk->vq = virtio_find_single_vq(vblk->vdev, virtblk_done, "requests"); if (IS_ERR(vblk->vq)) err = PTR_ERR(vblk->vq); @@ -477,6 +701,8 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) struct virtio_blk *vblk; struct request_queue *q; int err, index; + int pool_size; + u64 cap; u32 v, blk_size, sg_elems, opt_io_size; u16 min_io_size; @@ -506,10 +732,12 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) goto out_free_index; } + init_waitqueue_head(&vblk->queue_wait); vblk->vdev = vdev; vblk->sg_elems = sg_elems; sg_init_table(vblk->sg, vblk->sg_elems); mutex_init(&vblk->config_lock); + INIT_WORK(&vblk->config_work, virtblk_config_changed_work); vblk->config_enable = true; @@ -517,7 +745,10 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) if (err) goto out_free_vblk; - vblk->pool = mempool_create_kmalloc_pool(1,sizeof(struct virtblk_req)); + pool_size = sizeof(struct virtblk_req); + if (use_bio) + pool_size += sizeof(struct scatterlist) * sg_elems; + vblk->pool = mempool_create_kmalloc_pool(1, pool_size); if (!vblk->pool) { err = -ENOMEM; goto out_free_vq; @@ -530,12 +761,14 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) goto out_mempool; } - q = vblk->disk->queue = blk_init_queue(do_virtblk_request, NULL); + q = vblk->disk->queue = blk_init_queue(virtblk_request, NULL); if (!q) { err = -ENOMEM; goto out_put_disk; } + if (use_bio) + blk_queue_make_request(q, virtblk_make_request); q->queuedata = vblk; virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); @@ -620,7 +853,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) if (!err && opt_io_size) blk_queue_io_opt(q, blk_size * opt_io_size); - add_disk(vblk->disk); err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial); if (err) |