virtio_blk: blk-mq support
Switch virtio-blk from the dual support for old-style requests and bios to use the block-multiqueue. Acked-by: Asias He <asias@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Jens Axboe
parent
1355b37f11
commit
1cf7e9c68f
1 changed files with 65 additions and 257 deletions
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@ -11,12 +11,11 @@
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#include <linux/string_helpers.h>
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#include <scsi/scsi_cmnd.h>
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#include <linux/idr.h>
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#include <linux/blk-mq.h>
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#include <linux/numa.h>
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#define PART_BITS 4
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static bool use_bio;
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module_param(use_bio, bool, S_IRUGO);
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static int major;
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static DEFINE_IDA(vd_index_ida);
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@ -26,13 +25,11 @@ struct virtio_blk
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{
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struct virtio_device *vdev;
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struct virtqueue *vq;
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wait_queue_head_t queue_wait;
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spinlock_t vq_lock;
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/* The disk structure for the kernel. */
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struct gendisk *disk;
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mempool_t *pool;
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/* Process context for config space updates */
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struct work_struct config_work;
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@ -47,31 +44,17 @@ struct virtio_blk
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/* Ida index - used to track minor number allocations. */
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int index;
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/* Scatterlist: can be too big for stack. */
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struct scatterlist sg[/*sg_elems*/];
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};
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struct virtblk_req
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{
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struct request *req;
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struct bio *bio;
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struct virtio_blk_outhdr out_hdr;
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struct virtio_scsi_inhdr in_hdr;
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struct work_struct work;
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struct virtio_blk *vblk;
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int flags;
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u8 status;
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struct scatterlist sg[];
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};
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enum {
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VBLK_IS_FLUSH = 1,
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VBLK_REQ_FLUSH = 2,
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VBLK_REQ_DATA = 4,
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VBLK_REQ_FUA = 8,
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};
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static inline int virtblk_result(struct virtblk_req *vbr)
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{
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switch (vbr->status) {
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@ -84,22 +67,6 @@ static inline int virtblk_result(struct virtblk_req *vbr)
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}
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}
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static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk,
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gfp_t gfp_mask)
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{
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struct virtblk_req *vbr;
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vbr = mempool_alloc(vblk->pool, gfp_mask);
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if (!vbr)
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return NULL;
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vbr->vblk = vblk;
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if (use_bio)
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sg_init_table(vbr->sg, vblk->sg_elems);
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return vbr;
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}
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static int __virtblk_add_req(struct virtqueue *vq,
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struct virtblk_req *vbr,
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struct scatterlist *data_sg,
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@ -143,83 +110,8 @@ static int __virtblk_add_req(struct virtqueue *vq,
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return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
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}
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static void virtblk_add_req(struct virtblk_req *vbr, bool have_data)
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{
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struct virtio_blk *vblk = vbr->vblk;
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DEFINE_WAIT(wait);
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int ret;
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spin_lock_irq(vblk->disk->queue->queue_lock);
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while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr, vbr->sg,
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have_data)) < 0)) {
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prepare_to_wait_exclusive(&vblk->queue_wait, &wait,
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TASK_UNINTERRUPTIBLE);
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spin_unlock_irq(vblk->disk->queue->queue_lock);
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io_schedule();
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spin_lock_irq(vblk->disk->queue->queue_lock);
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finish_wait(&vblk->queue_wait, &wait);
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}
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virtqueue_kick(vblk->vq);
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spin_unlock_irq(vblk->disk->queue->queue_lock);
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}
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static void virtblk_bio_send_flush(struct virtblk_req *vbr)
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{
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vbr->flags |= VBLK_IS_FLUSH;
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vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
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vbr->out_hdr.sector = 0;
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vbr->out_hdr.ioprio = 0;
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virtblk_add_req(vbr, false);
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}
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static void virtblk_bio_send_data(struct virtblk_req *vbr)
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{
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struct virtio_blk *vblk = vbr->vblk;
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struct bio *bio = vbr->bio;
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bool have_data;
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vbr->flags &= ~VBLK_IS_FLUSH;
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vbr->out_hdr.type = 0;
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vbr->out_hdr.sector = bio->bi_sector;
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vbr->out_hdr.ioprio = bio_prio(bio);
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if (blk_bio_map_sg(vblk->disk->queue, bio, vbr->sg)) {
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have_data = true;
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if (bio->bi_rw & REQ_WRITE)
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vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
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else
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vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
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} else
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have_data = false;
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virtblk_add_req(vbr, have_data);
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}
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static void virtblk_bio_send_data_work(struct work_struct *work)
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{
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struct virtblk_req *vbr;
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vbr = container_of(work, struct virtblk_req, work);
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virtblk_bio_send_data(vbr);
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}
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static void virtblk_bio_send_flush_work(struct work_struct *work)
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{
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struct virtblk_req *vbr;
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vbr = container_of(work, struct virtblk_req, work);
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virtblk_bio_send_flush(vbr);
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}
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static inline void virtblk_request_done(struct virtblk_req *vbr)
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{
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struct virtio_blk *vblk = vbr->vblk;
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struct request *req = vbr->req;
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int error = virtblk_result(vbr);
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@ -231,90 +123,43 @@ static inline void virtblk_request_done(struct virtblk_req *vbr)
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req->errors = (error != 0);
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}
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__blk_end_request_all(req, error);
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mempool_free(vbr, vblk->pool);
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}
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static inline void virtblk_bio_flush_done(struct virtblk_req *vbr)
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{
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struct virtio_blk *vblk = vbr->vblk;
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if (vbr->flags & VBLK_REQ_DATA) {
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/* Send out the actual write data */
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INIT_WORK(&vbr->work, virtblk_bio_send_data_work);
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queue_work(virtblk_wq, &vbr->work);
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} else {
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bio_endio(vbr->bio, virtblk_result(vbr));
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mempool_free(vbr, vblk->pool);
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}
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}
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static inline void virtblk_bio_data_done(struct virtblk_req *vbr)
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{
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struct virtio_blk *vblk = vbr->vblk;
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if (unlikely(vbr->flags & VBLK_REQ_FUA)) {
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/* Send out a flush before end the bio */
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vbr->flags &= ~VBLK_REQ_DATA;
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INIT_WORK(&vbr->work, virtblk_bio_send_flush_work);
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queue_work(virtblk_wq, &vbr->work);
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} else {
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bio_endio(vbr->bio, virtblk_result(vbr));
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mempool_free(vbr, vblk->pool);
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}
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}
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static inline void virtblk_bio_done(struct virtblk_req *vbr)
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{
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if (unlikely(vbr->flags & VBLK_IS_FLUSH))
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virtblk_bio_flush_done(vbr);
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else
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virtblk_bio_data_done(vbr);
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blk_mq_end_io(req, error);
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}
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static void virtblk_done(struct virtqueue *vq)
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{
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struct virtio_blk *vblk = vq->vdev->priv;
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bool bio_done = false, req_done = false;
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bool req_done = false;
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struct virtblk_req *vbr;
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unsigned long flags;
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unsigned int len;
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spin_lock_irqsave(vblk->disk->queue->queue_lock, flags);
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spin_lock_irqsave(&vblk->vq_lock, flags);
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do {
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virtqueue_disable_cb(vq);
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while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) {
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if (vbr->bio) {
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virtblk_bio_done(vbr);
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bio_done = true;
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} else {
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virtblk_request_done(vbr);
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req_done = true;
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}
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virtblk_request_done(vbr);
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req_done = true;
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}
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} while (!virtqueue_enable_cb(vq));
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spin_unlock_irqrestore(&vblk->vq_lock, flags);
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/* In case queue is stopped waiting for more buffers. */
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if (req_done)
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blk_start_queue(vblk->disk->queue);
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spin_unlock_irqrestore(vblk->disk->queue->queue_lock, flags);
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if (bio_done)
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wake_up(&vblk->queue_wait);
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blk_mq_start_stopped_hw_queues(vblk->disk->queue);
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}
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static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
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struct request *req)
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static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
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{
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struct virtio_blk *vblk = hctx->queue->queuedata;
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struct virtblk_req *vbr = req->special;
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unsigned long flags;
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unsigned int num;
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struct virtblk_req *vbr;
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const bool last = (req->cmd_flags & REQ_END) != 0;
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vbr = virtblk_alloc_req(vblk, GFP_ATOMIC);
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if (!vbr)
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/* When another request finishes we'll try again. */
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return false;
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BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
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vbr->req = req;
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vbr->bio = NULL;
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if (req->cmd_flags & REQ_FLUSH) {
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vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
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vbr->out_hdr.sector = 0;
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@ -342,7 +187,7 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
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}
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}
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num = blk_rq_map_sg(q, vbr->req, vblk->sg);
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num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg);
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if (num) {
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if (rq_data_dir(vbr->req) == WRITE)
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vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
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@ -350,63 +195,18 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
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vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
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}
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if (__virtblk_add_req(vblk->vq, vbr, vblk->sg, num) < 0) {
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mempool_free(vbr, vblk->pool);
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return false;
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}
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return true;
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}
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static void virtblk_request(struct request_queue *q)
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{
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struct virtio_blk *vblk = q->queuedata;
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struct request *req;
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unsigned int issued = 0;
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while ((req = blk_peek_request(q)) != NULL) {
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BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
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/* If this request fails, stop queue and wait for something to
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finish to restart it. */
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if (!do_req(q, vblk, req)) {
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blk_stop_queue(q);
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break;
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}
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blk_start_request(req);
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issued++;
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}
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if (issued)
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spin_lock_irqsave(&vblk->vq_lock, flags);
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if (__virtblk_add_req(vblk->vq, vbr, vbr->sg, num) < 0) {
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spin_unlock_irqrestore(&vblk->vq_lock, flags);
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blk_mq_stop_hw_queue(hctx);
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virtqueue_kick(vblk->vq);
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}
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static void virtblk_make_request(struct request_queue *q, struct bio *bio)
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{
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struct virtio_blk *vblk = q->queuedata;
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struct virtblk_req *vbr;
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BUG_ON(bio->bi_phys_segments + 2 > vblk->sg_elems);
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vbr = virtblk_alloc_req(vblk, GFP_NOIO);
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if (!vbr) {
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bio_endio(bio, -ENOMEM);
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return;
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return BLK_MQ_RQ_QUEUE_BUSY;
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}
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spin_unlock_irqrestore(&vblk->vq_lock, flags);
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vbr->bio = bio;
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vbr->flags = 0;
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if (bio->bi_rw & REQ_FLUSH)
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vbr->flags |= VBLK_REQ_FLUSH;
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if (bio->bi_rw & REQ_FUA)
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vbr->flags |= VBLK_REQ_FUA;
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if (bio->bi_size)
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vbr->flags |= VBLK_REQ_DATA;
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if (unlikely(vbr->flags & VBLK_REQ_FLUSH))
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virtblk_bio_send_flush(vbr);
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else
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virtblk_bio_send_data(vbr);
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if (last)
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virtqueue_kick(vblk->vq);
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return BLK_MQ_RQ_QUEUE_OK;
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}
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/* return id (s/n) string for *disk to *id_str
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@ -680,12 +480,35 @@ static const struct device_attribute dev_attr_cache_type_rw =
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__ATTR(cache_type, S_IRUGO|S_IWUSR,
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virtblk_cache_type_show, virtblk_cache_type_store);
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static struct blk_mq_ops virtio_mq_ops = {
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.queue_rq = virtio_queue_rq,
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.map_queue = blk_mq_map_queue,
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.alloc_hctx = blk_mq_alloc_single_hw_queue,
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.free_hctx = blk_mq_free_single_hw_queue,
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};
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static struct blk_mq_reg virtio_mq_reg = {
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.ops = &virtio_mq_ops,
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.nr_hw_queues = 1,
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.queue_depth = 64,
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.numa_node = NUMA_NO_NODE,
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.flags = BLK_MQ_F_SHOULD_MERGE,
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};
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static void virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx,
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struct request *rq, unsigned int nr)
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{
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struct virtio_blk *vblk = data;
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struct virtblk_req *vbr = rq->special;
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sg_init_table(vbr->sg, vblk->sg_elems);
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}
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static int virtblk_probe(struct virtio_device *vdev)
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{
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struct virtio_blk *vblk;
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struct request_queue *q;
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int err, index;
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int pool_size;
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u64 cap;
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u32 v, blk_size, sg_elems, opt_io_size;
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@ -709,17 +532,14 @@ static int virtblk_probe(struct virtio_device *vdev)
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/* We need an extra sg elements at head and tail. */
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sg_elems += 2;
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vdev->priv = vblk = kmalloc(sizeof(*vblk) +
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sizeof(vblk->sg[0]) * sg_elems, GFP_KERNEL);
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vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
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if (!vblk) {
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err = -ENOMEM;
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goto out_free_index;
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}
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init_waitqueue_head(&vblk->queue_wait);
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vblk->vdev = vdev;
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vblk->sg_elems = sg_elems;
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sg_init_table(vblk->sg, vblk->sg_elems);
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mutex_init(&vblk->config_lock);
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INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
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@ -728,31 +548,27 @@ static int virtblk_probe(struct virtio_device *vdev)
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err = init_vq(vblk);
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if (err)
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goto out_free_vblk;
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pool_size = sizeof(struct virtblk_req);
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if (use_bio)
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pool_size += sizeof(struct scatterlist) * sg_elems;
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vblk->pool = mempool_create_kmalloc_pool(1, pool_size);
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if (!vblk->pool) {
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err = -ENOMEM;
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goto out_free_vq;
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}
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spin_lock_init(&vblk->vq_lock);
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/* FIXME: How many partitions? How long is a piece of string? */
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vblk->disk = alloc_disk(1 << PART_BITS);
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if (!vblk->disk) {
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err = -ENOMEM;
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goto out_mempool;
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goto out_free_vq;
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}
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q = vblk->disk->queue = blk_init_queue(virtblk_request, NULL);
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virtio_mq_reg.cmd_size =
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sizeof(struct virtblk_req) +
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sizeof(struct scatterlist) * sg_elems;
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q = vblk->disk->queue = blk_mq_init_queue(&virtio_mq_reg, vblk);
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if (!q) {
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err = -ENOMEM;
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goto out_put_disk;
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}
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if (use_bio)
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blk_queue_make_request(q, virtblk_make_request);
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blk_mq_init_commands(q, virtblk_init_vbr, vblk);
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q->queuedata = vblk;
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||||
virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
|
||||
|
|
@ -857,8 +673,6 @@ static int virtblk_probe(struct virtio_device *vdev)
|
|||
blk_cleanup_queue(vblk->disk->queue);
|
||||
out_put_disk:
|
||||
put_disk(vblk->disk);
|
||||
out_mempool:
|
||||
mempool_destroy(vblk->pool);
|
||||
out_free_vq:
|
||||
vdev->config->del_vqs(vdev);
|
||||
out_free_vblk:
|
||||
|
|
@ -890,7 +704,6 @@ static void virtblk_remove(struct virtio_device *vdev)
|
|||
|
||||
refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
|
||||
put_disk(vblk->disk);
|
||||
mempool_destroy(vblk->pool);
|
||||
vdev->config->del_vqs(vdev);
|
||||
kfree(vblk);
|
||||
|
||||
|
|
@ -914,10 +727,7 @@ static int virtblk_freeze(struct virtio_device *vdev)
|
|||
|
||||
flush_work(&vblk->config_work);
|
||||
|
||||
spin_lock_irq(vblk->disk->queue->queue_lock);
|
||||
blk_stop_queue(vblk->disk->queue);
|
||||
spin_unlock_irq(vblk->disk->queue->queue_lock);
|
||||
blk_sync_queue(vblk->disk->queue);
|
||||
blk_mq_stop_hw_queues(vblk->disk->queue);
|
||||
|
||||
vdev->config->del_vqs(vdev);
|
||||
return 0;
|
||||
|
|
@ -930,11 +740,9 @@ static int virtblk_restore(struct virtio_device *vdev)
|
|||
|
||||
vblk->config_enable = true;
|
||||
ret = init_vq(vdev->priv);
|
||||
if (!ret) {
|
||||
spin_lock_irq(vblk->disk->queue->queue_lock);
|
||||
blk_start_queue(vblk->disk->queue);
|
||||
spin_unlock_irq(vblk->disk->queue->queue_lock);
|
||||
}
|
||||
if (!ret)
|
||||
blk_mq_start_stopped_hw_queues(vblk->disk->queue);
|
||||
|
||||
return ret;
|
||||
}
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in a new issue