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1034 lines
26 KiB
1034 lines
26 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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//#define DEBUG |
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#include <linux/spinlock.h> |
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#include <linux/slab.h> |
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#include <linux/blkdev.h> |
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#include <linux/hdreg.h> |
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#include <linux/module.h> |
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#include <linux/mutex.h> |
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#include <linux/interrupt.h> |
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#include <linux/virtio.h> |
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#include <linux/virtio_blk.h> |
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#include <linux/scatterlist.h> |
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#include <linux/string_helpers.h> |
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#include <linux/idr.h> |
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#include <linux/blk-mq.h> |
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#include <linux/blk-mq-virtio.h> |
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#include <linux/numa.h> |
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#include <uapi/linux/virtio_ring.h> |
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|
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#define PART_BITS 4 |
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#define VQ_NAME_LEN 16 |
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#define MAX_DISCARD_SEGMENTS 256u |
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|
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/* The maximum number of sg elements that fit into a virtqueue */ |
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#define VIRTIO_BLK_MAX_SG_ELEMS 32768 |
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|
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static int major; |
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static DEFINE_IDA(vd_index_ida); |
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|
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static struct workqueue_struct *virtblk_wq; |
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|
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struct virtio_blk_vq { |
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struct virtqueue *vq; |
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spinlock_t lock; |
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char name[VQ_NAME_LEN]; |
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} ____cacheline_aligned_in_smp; |
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|
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struct virtio_blk { |
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/* |
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* This mutex must be held by anything that may run after |
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* virtblk_remove() sets vblk->vdev to NULL. |
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* |
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* blk-mq, virtqueue processing, and sysfs attribute code paths are |
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* shut down before vblk->vdev is set to NULL and therefore do not need |
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* to hold this mutex. |
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*/ |
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struct mutex vdev_mutex; |
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struct virtio_device *vdev; |
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|
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/* The disk structure for the kernel. */ |
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struct gendisk *disk; |
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|
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/* Block layer tags. */ |
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struct blk_mq_tag_set tag_set; |
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|
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/* Process context for config space updates */ |
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struct work_struct config_work; |
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|
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/* |
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* Tracks references from block_device_operations open/release and |
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* virtio_driver probe/remove so this object can be freed once no |
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* longer in use. |
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*/ |
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refcount_t refs; |
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|
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/* What host tells us, plus 2 for header & tailer. */ |
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unsigned int sg_elems; |
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|
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/* Ida index - used to track minor number allocations. */ |
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int index; |
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|
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/* num of vqs */ |
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int num_vqs; |
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struct virtio_blk_vq *vqs; |
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}; |
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|
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struct virtblk_req { |
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struct virtio_blk_outhdr out_hdr; |
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u8 status; |
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struct scatterlist sg[]; |
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}; |
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|
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static inline blk_status_t virtblk_result(struct virtblk_req *vbr) |
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{ |
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switch (vbr->status) { |
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case VIRTIO_BLK_S_OK: |
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return BLK_STS_OK; |
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case VIRTIO_BLK_S_UNSUPP: |
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return BLK_STS_NOTSUPP; |
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default: |
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return BLK_STS_IOERR; |
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} |
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} |
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|
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static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr, |
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struct scatterlist *data_sg, bool have_data) |
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{ |
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struct scatterlist hdr, status, *sgs[3]; |
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unsigned int num_out = 0, num_in = 0; |
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|
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sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); |
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sgs[num_out++] = &hdr; |
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|
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if (have_data) { |
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if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) |
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sgs[num_out++] = data_sg; |
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else |
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sgs[num_out + num_in++] = data_sg; |
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} |
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|
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sg_init_one(&status, &vbr->status, sizeof(vbr->status)); |
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sgs[num_out + num_in++] = &status; |
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|
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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 int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap) |
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{ |
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unsigned short segments = blk_rq_nr_discard_segments(req); |
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unsigned short n = 0; |
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struct virtio_blk_discard_write_zeroes *range; |
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struct bio *bio; |
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u32 flags = 0; |
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|
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if (unmap) |
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flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; |
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range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC); |
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if (!range) |
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return -ENOMEM; |
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|
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/* |
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* Single max discard segment means multi-range discard isn't |
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* supported, and block layer only runs contiguity merge like |
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* normal RW request. So we can't reply on bio for retrieving |
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* each range info. |
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*/ |
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if (queue_max_discard_segments(req->q) == 1) { |
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range[0].flags = cpu_to_le32(flags); |
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range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req)); |
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range[0].sector = cpu_to_le64(blk_rq_pos(req)); |
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n = 1; |
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} else { |
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__rq_for_each_bio(bio, req) { |
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u64 sector = bio->bi_iter.bi_sector; |
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u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; |
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|
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range[n].flags = cpu_to_le32(flags); |
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range[n].num_sectors = cpu_to_le32(num_sectors); |
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range[n].sector = cpu_to_le64(sector); |
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n++; |
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} |
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} |
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WARN_ON_ONCE(n != segments); |
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|
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req->special_vec.bv_page = virt_to_page(range); |
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req->special_vec.bv_offset = offset_in_page(range); |
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req->special_vec.bv_len = sizeof(*range) * segments; |
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req->rq_flags |= RQF_SPECIAL_PAYLOAD; |
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|
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return 0; |
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} |
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static inline void virtblk_request_done(struct request *req) |
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{ |
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struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); |
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|
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if (req->rq_flags & RQF_SPECIAL_PAYLOAD) |
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kfree(bvec_virt(&req->special_vec)); |
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blk_mq_end_request(req, virtblk_result(vbr)); |
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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 req_done = false; |
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int qid = vq->index; |
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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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|
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spin_lock_irqsave(&vblk->vqs[qid].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->vqs[qid].vq, &len)) != NULL) { |
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struct request *req = blk_mq_rq_from_pdu(vbr); |
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|
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if (likely(!blk_should_fake_timeout(req->q))) |
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blk_mq_complete_request(req); |
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req_done = true; |
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} |
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if (unlikely(virtqueue_is_broken(vq))) |
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break; |
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} while (!virtqueue_enable_cb(vq)); |
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|
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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_mq_start_stopped_hw_queues(vblk->disk->queue, true); |
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spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); |
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} |
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static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) |
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{ |
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struct virtio_blk *vblk = hctx->queue->queuedata; |
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struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; |
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bool kick; |
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|
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spin_lock_irq(&vq->lock); |
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kick = virtqueue_kick_prepare(vq->vq); |
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spin_unlock_irq(&vq->lock); |
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if (kick) |
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virtqueue_notify(vq->vq); |
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} |
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static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, |
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const struct blk_mq_queue_data *bd) |
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{ |
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struct virtio_blk *vblk = hctx->queue->queuedata; |
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struct request *req = bd->rq; |
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struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); |
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unsigned long flags; |
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unsigned int num; |
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int qid = hctx->queue_num; |
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int err; |
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bool notify = false; |
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bool unmap = false; |
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u32 type; |
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|
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BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems); |
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switch (req_op(req)) { |
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case REQ_OP_READ: |
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case REQ_OP_WRITE: |
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type = 0; |
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break; |
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case REQ_OP_FLUSH: |
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type = VIRTIO_BLK_T_FLUSH; |
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break; |
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case REQ_OP_DISCARD: |
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type = VIRTIO_BLK_T_DISCARD; |
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break; |
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case REQ_OP_WRITE_ZEROES: |
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type = VIRTIO_BLK_T_WRITE_ZEROES; |
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unmap = !(req->cmd_flags & REQ_NOUNMAP); |
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break; |
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case REQ_OP_DRV_IN: |
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type = VIRTIO_BLK_T_GET_ID; |
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break; |
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default: |
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WARN_ON_ONCE(1); |
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return BLK_STS_IOERR; |
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} |
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vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type); |
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vbr->out_hdr.sector = type ? |
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0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req)); |
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vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req)); |
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|
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blk_mq_start_request(req); |
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|
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if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) { |
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err = virtblk_setup_discard_write_zeroes(req, unmap); |
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if (err) |
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return BLK_STS_RESOURCE; |
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} |
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num = blk_rq_map_sg(hctx->queue, req, vbr->sg); |
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if (num) { |
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if (rq_data_dir(req) == WRITE) |
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vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT); |
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else |
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vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN); |
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} |
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spin_lock_irqsave(&vblk->vqs[qid].lock, flags); |
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err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num); |
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if (err) { |
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virtqueue_kick(vblk->vqs[qid].vq); |
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/* Don't stop the queue if -ENOMEM: we may have failed to |
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* bounce the buffer due to global resource outage. |
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*/ |
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if (err == -ENOSPC) |
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blk_mq_stop_hw_queue(hctx); |
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spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); |
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switch (err) { |
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case -ENOSPC: |
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return BLK_STS_DEV_RESOURCE; |
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case -ENOMEM: |
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return BLK_STS_RESOURCE; |
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default: |
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return BLK_STS_IOERR; |
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} |
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} |
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if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) |
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notify = true; |
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spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); |
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|
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if (notify) |
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virtqueue_notify(vblk->vqs[qid].vq); |
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return BLK_STS_OK; |
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} |
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|
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/* return id (s/n) string for *disk to *id_str |
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*/ |
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static int virtblk_get_id(struct gendisk *disk, char *id_str) |
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{ |
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struct virtio_blk *vblk = disk->private_data; |
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struct request_queue *q = vblk->disk->queue; |
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struct request *req; |
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int err; |
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req = blk_get_request(q, REQ_OP_DRV_IN, 0); |
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if (IS_ERR(req)) |
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return PTR_ERR(req); |
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|
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err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); |
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if (err) |
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goto out; |
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blk_execute_rq(vblk->disk, req, false); |
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err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req))); |
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out: |
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blk_put_request(req); |
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return err; |
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} |
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|
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static void virtblk_get(struct virtio_blk *vblk) |
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{ |
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refcount_inc(&vblk->refs); |
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} |
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|
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static void virtblk_put(struct virtio_blk *vblk) |
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{ |
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if (refcount_dec_and_test(&vblk->refs)) { |
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ida_simple_remove(&vd_index_ida, vblk->index); |
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mutex_destroy(&vblk->vdev_mutex); |
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kfree(vblk); |
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} |
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} |
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|
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static int virtblk_open(struct block_device *bd, fmode_t mode) |
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{ |
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struct virtio_blk *vblk = bd->bd_disk->private_data; |
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int ret = 0; |
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|
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mutex_lock(&vblk->vdev_mutex); |
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|
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if (vblk->vdev) |
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virtblk_get(vblk); |
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else |
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ret = -ENXIO; |
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|
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mutex_unlock(&vblk->vdev_mutex); |
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return ret; |
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} |
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|
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static void virtblk_release(struct gendisk *disk, fmode_t mode) |
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{ |
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struct virtio_blk *vblk = disk->private_data; |
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|
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virtblk_put(vblk); |
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} |
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|
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/* We provide getgeo only to please some old bootloader/partitioning tools */ |
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static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) |
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{ |
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struct virtio_blk *vblk = bd->bd_disk->private_data; |
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int ret = 0; |
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|
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mutex_lock(&vblk->vdev_mutex); |
|
|
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if (!vblk->vdev) { |
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ret = -ENXIO; |
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goto out; |
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} |
|
|
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/* see if the host passed in geometry config */ |
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if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { |
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virtio_cread(vblk->vdev, struct virtio_blk_config, |
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geometry.cylinders, &geo->cylinders); |
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virtio_cread(vblk->vdev, struct virtio_blk_config, |
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geometry.heads, &geo->heads); |
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virtio_cread(vblk->vdev, struct virtio_blk_config, |
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geometry.sectors, &geo->sectors); |
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} else { |
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/* some standard values, similar to sd */ |
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geo->heads = 1 << 6; |
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geo->sectors = 1 << 5; |
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geo->cylinders = get_capacity(bd->bd_disk) >> 11; |
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} |
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out: |
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mutex_unlock(&vblk->vdev_mutex); |
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return ret; |
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} |
|
|
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static const struct block_device_operations virtblk_fops = { |
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.owner = THIS_MODULE, |
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.open = virtblk_open, |
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.release = virtblk_release, |
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.getgeo = virtblk_getgeo, |
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}; |
|
|
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static int index_to_minor(int index) |
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{ |
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return index << PART_BITS; |
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} |
|
|
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static int minor_to_index(int minor) |
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{ |
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return minor >> PART_BITS; |
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} |
|
|
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static ssize_t serial_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct gendisk *disk = dev_to_disk(dev); |
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int err; |
|
|
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/* sysfs gives us a PAGE_SIZE buffer */ |
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BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); |
|
|
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buf[VIRTIO_BLK_ID_BYTES] = '\0'; |
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err = virtblk_get_id(disk, buf); |
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if (!err) |
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return strlen(buf); |
|
|
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if (err == -EIO) /* Unsupported? Make it empty. */ |
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return 0; |
|
|
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return err; |
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} |
|
|
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static DEVICE_ATTR_RO(serial); |
|
|
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/* The queue's logical block size must be set before calling this */ |
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static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) |
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{ |
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struct virtio_device *vdev = vblk->vdev; |
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struct request_queue *q = vblk->disk->queue; |
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char cap_str_2[10], cap_str_10[10]; |
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unsigned long long nblocks; |
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u64 capacity; |
|
|
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/* Host must always specify the capacity. */ |
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virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); |
|
|
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nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); |
|
|
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string_get_size(nblocks, queue_logical_block_size(q), |
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STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); |
|
string_get_size(nblocks, queue_logical_block_size(q), |
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STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); |
|
|
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dev_notice(&vdev->dev, |
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"[%s] %s%llu %d-byte logical blocks (%s/%s)\n", |
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vblk->disk->disk_name, |
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resize ? "new size: " : "", |
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nblocks, |
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queue_logical_block_size(q), |
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cap_str_10, |
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cap_str_2); |
|
|
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set_capacity_and_notify(vblk->disk, capacity); |
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} |
|
|
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static void virtblk_config_changed_work(struct work_struct *work) |
|
{ |
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struct virtio_blk *vblk = |
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container_of(work, struct virtio_blk, config_work); |
|
|
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virtblk_update_capacity(vblk, true); |
|
} |
|
|
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static void virtblk_config_changed(struct virtio_device *vdev) |
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{ |
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struct virtio_blk *vblk = vdev->priv; |
|
|
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queue_work(virtblk_wq, &vblk->config_work); |
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} |
|
|
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static int init_vq(struct virtio_blk *vblk) |
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{ |
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int err; |
|
int i; |
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vq_callback_t **callbacks; |
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const char **names; |
|
struct virtqueue **vqs; |
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unsigned short num_vqs; |
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struct virtio_device *vdev = vblk->vdev; |
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struct irq_affinity desc = { 0, }; |
|
|
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err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, |
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struct virtio_blk_config, num_queues, |
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&num_vqs); |
|
if (err) |
|
num_vqs = 1; |
|
|
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num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); |
|
|
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vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); |
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if (!vblk->vqs) |
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return -ENOMEM; |
|
|
|
names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); |
|
callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); |
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vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); |
|
if (!names || !callbacks || !vqs) { |
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err = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
for (i = 0; i < num_vqs; i++) { |
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callbacks[i] = virtblk_done; |
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snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i); |
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names[i] = vblk->vqs[i].name; |
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} |
|
|
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/* Discover virtqueues and write information to configuration. */ |
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err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); |
|
if (err) |
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goto out; |
|
|
|
for (i = 0; i < num_vqs; i++) { |
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spin_lock_init(&vblk->vqs[i].lock); |
|
vblk->vqs[i].vq = vqs[i]; |
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} |
|
vblk->num_vqs = num_vqs; |
|
|
|
out: |
|
kfree(vqs); |
|
kfree(callbacks); |
|
kfree(names); |
|
if (err) |
|
kfree(vblk->vqs); |
|
return err; |
|
} |
|
|
|
/* |
|
* Legacy naming scheme used for virtio devices. We are stuck with it for |
|
* virtio blk but don't ever use it for any new driver. |
|
*/ |
|
static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) |
|
{ |
|
const int base = 'z' - 'a' + 1; |
|
char *begin = buf + strlen(prefix); |
|
char *end = buf + buflen; |
|
char *p; |
|
int unit; |
|
|
|
p = end - 1; |
|
*p = '\0'; |
|
unit = base; |
|
do { |
|
if (p == begin) |
|
return -EINVAL; |
|
*--p = 'a' + (index % unit); |
|
index = (index / unit) - 1; |
|
} while (index >= 0); |
|
|
|
memmove(begin, p, end - p); |
|
memcpy(buf, prefix, strlen(prefix)); |
|
|
|
return 0; |
|
} |
|
|
|
static int virtblk_get_cache_mode(struct virtio_device *vdev) |
|
{ |
|
u8 writeback; |
|
int err; |
|
|
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, |
|
struct virtio_blk_config, wce, |
|
&writeback); |
|
|
|
/* |
|
* If WCE is not configurable and flush is not available, |
|
* assume no writeback cache is in use. |
|
*/ |
|
if (err) |
|
writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); |
|
|
|
return writeback; |
|
} |
|
|
|
static void virtblk_update_cache_mode(struct virtio_device *vdev) |
|
{ |
|
u8 writeback = virtblk_get_cache_mode(vdev); |
|
struct virtio_blk *vblk = vdev->priv; |
|
|
|
blk_queue_write_cache(vblk->disk->queue, writeback, false); |
|
} |
|
|
|
static const char *const virtblk_cache_types[] = { |
|
"write through", "write back" |
|
}; |
|
|
|
static ssize_t |
|
cache_type_store(struct device *dev, struct device_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
struct gendisk *disk = dev_to_disk(dev); |
|
struct virtio_blk *vblk = disk->private_data; |
|
struct virtio_device *vdev = vblk->vdev; |
|
int i; |
|
|
|
BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); |
|
i = sysfs_match_string(virtblk_cache_types, buf); |
|
if (i < 0) |
|
return i; |
|
|
|
virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); |
|
virtblk_update_cache_mode(vdev); |
|
return count; |
|
} |
|
|
|
static ssize_t |
|
cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) |
|
{ |
|
struct gendisk *disk = dev_to_disk(dev); |
|
struct virtio_blk *vblk = disk->private_data; |
|
u8 writeback = virtblk_get_cache_mode(vblk->vdev); |
|
|
|
BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); |
|
return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]); |
|
} |
|
|
|
static DEVICE_ATTR_RW(cache_type); |
|
|
|
static struct attribute *virtblk_attrs[] = { |
|
&dev_attr_serial.attr, |
|
&dev_attr_cache_type.attr, |
|
NULL, |
|
}; |
|
|
|
static umode_t virtblk_attrs_are_visible(struct kobject *kobj, |
|
struct attribute *a, int n) |
|
{ |
|
struct device *dev = kobj_to_dev(kobj); |
|
struct gendisk *disk = dev_to_disk(dev); |
|
struct virtio_blk *vblk = disk->private_data; |
|
struct virtio_device *vdev = vblk->vdev; |
|
|
|
if (a == &dev_attr_cache_type.attr && |
|
!virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) |
|
return S_IRUGO; |
|
|
|
return a->mode; |
|
} |
|
|
|
static const struct attribute_group virtblk_attr_group = { |
|
.attrs = virtblk_attrs, |
|
.is_visible = virtblk_attrs_are_visible, |
|
}; |
|
|
|
static const struct attribute_group *virtblk_attr_groups[] = { |
|
&virtblk_attr_group, |
|
NULL, |
|
}; |
|
|
|
static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq, |
|
unsigned int hctx_idx, unsigned int numa_node) |
|
{ |
|
struct virtio_blk *vblk = set->driver_data; |
|
struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq); |
|
|
|
sg_init_table(vbr->sg, vblk->sg_elems); |
|
return 0; |
|
} |
|
|
|
static int virtblk_map_queues(struct blk_mq_tag_set *set) |
|
{ |
|
struct virtio_blk *vblk = set->driver_data; |
|
|
|
return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT], |
|
vblk->vdev, 0); |
|
} |
|
|
|
static const struct blk_mq_ops virtio_mq_ops = { |
|
.queue_rq = virtio_queue_rq, |
|
.commit_rqs = virtio_commit_rqs, |
|
.complete = virtblk_request_done, |
|
.init_request = virtblk_init_request, |
|
.map_queues = virtblk_map_queues, |
|
}; |
|
|
|
static unsigned int virtblk_queue_depth; |
|
module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); |
|
|
|
static int virtblk_probe(struct virtio_device *vdev) |
|
{ |
|
struct virtio_blk *vblk; |
|
struct request_queue *q; |
|
int err, index; |
|
|
|
u32 v, blk_size, max_size, sg_elems, opt_io_size; |
|
u16 min_io_size; |
|
u8 physical_block_exp, alignment_offset; |
|
unsigned int queue_depth; |
|
|
|
if (!vdev->config->get) { |
|
dev_err(&vdev->dev, "%s failure: config access disabled\n", |
|
__func__); |
|
return -EINVAL; |
|
} |
|
|
|
err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS), |
|
GFP_KERNEL); |
|
if (err < 0) |
|
goto out; |
|
index = err; |
|
|
|
/* We need to know how many segments before we allocate. */ |
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, |
|
struct virtio_blk_config, seg_max, |
|
&sg_elems); |
|
|
|
/* We need at least one SG element, whatever they say. */ |
|
if (err || !sg_elems) |
|
sg_elems = 1; |
|
|
|
/* Prevent integer overflows and honor max vq size */ |
|
sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2); |
|
|
|
/* We need extra sg elements at head and tail. */ |
|
sg_elems += 2; |
|
vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); |
|
if (!vblk) { |
|
err = -ENOMEM; |
|
goto out_free_index; |
|
} |
|
|
|
/* This reference is dropped in virtblk_remove(). */ |
|
refcount_set(&vblk->refs, 1); |
|
mutex_init(&vblk->vdev_mutex); |
|
|
|
vblk->vdev = vdev; |
|
vblk->sg_elems = sg_elems; |
|
|
|
INIT_WORK(&vblk->config_work, virtblk_config_changed_work); |
|
|
|
err = init_vq(vblk); |
|
if (err) |
|
goto out_free_vblk; |
|
|
|
/* Default queue sizing is to fill the ring. */ |
|
if (!virtblk_queue_depth) { |
|
queue_depth = vblk->vqs[0].vq->num_free; |
|
/* ... but without indirect descs, we use 2 descs per req */ |
|
if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) |
|
queue_depth /= 2; |
|
} else { |
|
queue_depth = virtblk_queue_depth; |
|
} |
|
|
|
memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); |
|
vblk->tag_set.ops = &virtio_mq_ops; |
|
vblk->tag_set.queue_depth = queue_depth; |
|
vblk->tag_set.numa_node = NUMA_NO_NODE; |
|
vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; |
|
vblk->tag_set.cmd_size = |
|
sizeof(struct virtblk_req) + |
|
sizeof(struct scatterlist) * sg_elems; |
|
vblk->tag_set.driver_data = vblk; |
|
vblk->tag_set.nr_hw_queues = vblk->num_vqs; |
|
|
|
err = blk_mq_alloc_tag_set(&vblk->tag_set); |
|
if (err) |
|
goto out_free_vq; |
|
|
|
vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, vblk); |
|
if (IS_ERR(vblk->disk)) { |
|
err = PTR_ERR(vblk->disk); |
|
goto out_free_tags; |
|
} |
|
q = vblk->disk->queue; |
|
|
|
virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); |
|
|
|
vblk->disk->major = major; |
|
vblk->disk->first_minor = index_to_minor(index); |
|
vblk->disk->minors = 1 << PART_BITS; |
|
vblk->disk->private_data = vblk; |
|
vblk->disk->fops = &virtblk_fops; |
|
vblk->disk->flags |= GENHD_FL_EXT_DEVT; |
|
vblk->index = index; |
|
|
|
/* configure queue flush support */ |
|
virtblk_update_cache_mode(vdev); |
|
|
|
/* If disk is read-only in the host, the guest should obey */ |
|
if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) |
|
set_disk_ro(vblk->disk, 1); |
|
|
|
/* We can handle whatever the host told us to handle. */ |
|
blk_queue_max_segments(q, vblk->sg_elems-2); |
|
|
|
/* No real sector limit. */ |
|
blk_queue_max_hw_sectors(q, -1U); |
|
|
|
max_size = virtio_max_dma_size(vdev); |
|
|
|
/* Host can optionally specify maximum segment size and number of |
|
* segments. */ |
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, |
|
struct virtio_blk_config, size_max, &v); |
|
if (!err) |
|
max_size = min(max_size, v); |
|
|
|
blk_queue_max_segment_size(q, max_size); |
|
|
|
/* Host can optionally specify the block size of the device */ |
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, |
|
struct virtio_blk_config, blk_size, |
|
&blk_size); |
|
if (!err) |
|
blk_queue_logical_block_size(q, blk_size); |
|
else |
|
blk_size = queue_logical_block_size(q); |
|
|
|
/* Use topology information if available */ |
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, |
|
struct virtio_blk_config, physical_block_exp, |
|
&physical_block_exp); |
|
if (!err && physical_block_exp) |
|
blk_queue_physical_block_size(q, |
|
blk_size * (1 << physical_block_exp)); |
|
|
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, |
|
struct virtio_blk_config, alignment_offset, |
|
&alignment_offset); |
|
if (!err && alignment_offset) |
|
blk_queue_alignment_offset(q, blk_size * alignment_offset); |
|
|
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, |
|
struct virtio_blk_config, min_io_size, |
|
&min_io_size); |
|
if (!err && min_io_size) |
|
blk_queue_io_min(q, blk_size * min_io_size); |
|
|
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, |
|
struct virtio_blk_config, opt_io_size, |
|
&opt_io_size); |
|
if (!err && opt_io_size) |
|
blk_queue_io_opt(q, blk_size * opt_io_size); |
|
|
|
if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { |
|
q->limits.discard_granularity = blk_size; |
|
|
|
virtio_cread(vdev, struct virtio_blk_config, |
|
discard_sector_alignment, &v); |
|
q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0; |
|
|
|
virtio_cread(vdev, struct virtio_blk_config, |
|
max_discard_sectors, &v); |
|
blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); |
|
|
|
virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, |
|
&v); |
|
blk_queue_max_discard_segments(q, |
|
min_not_zero(v, |
|
MAX_DISCARD_SEGMENTS)); |
|
|
|
blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); |
|
} |
|
|
|
if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { |
|
virtio_cread(vdev, struct virtio_blk_config, |
|
max_write_zeroes_sectors, &v); |
|
blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); |
|
} |
|
|
|
virtblk_update_capacity(vblk, false); |
|
virtio_device_ready(vdev); |
|
|
|
err = device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); |
|
if (err) |
|
goto out_cleanup_disk; |
|
|
|
return 0; |
|
|
|
out_cleanup_disk: |
|
blk_cleanup_disk(vblk->disk); |
|
out_free_tags: |
|
blk_mq_free_tag_set(&vblk->tag_set); |
|
out_free_vq: |
|
vdev->config->del_vqs(vdev); |
|
kfree(vblk->vqs); |
|
out_free_vblk: |
|
kfree(vblk); |
|
out_free_index: |
|
ida_simple_remove(&vd_index_ida, index); |
|
out: |
|
return err; |
|
} |
|
|
|
static void virtblk_remove(struct virtio_device *vdev) |
|
{ |
|
struct virtio_blk *vblk = vdev->priv; |
|
|
|
/* Make sure no work handler is accessing the device. */ |
|
flush_work(&vblk->config_work); |
|
|
|
del_gendisk(vblk->disk); |
|
blk_cleanup_disk(vblk->disk); |
|
blk_mq_free_tag_set(&vblk->tag_set); |
|
|
|
mutex_lock(&vblk->vdev_mutex); |
|
|
|
/* Stop all the virtqueues. */ |
|
vdev->config->reset(vdev); |
|
|
|
/* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ |
|
vblk->vdev = NULL; |
|
|
|
vdev->config->del_vqs(vdev); |
|
kfree(vblk->vqs); |
|
|
|
mutex_unlock(&vblk->vdev_mutex); |
|
|
|
virtblk_put(vblk); |
|
} |
|
|
|
#ifdef CONFIG_PM_SLEEP |
|
static int virtblk_freeze(struct virtio_device *vdev) |
|
{ |
|
struct virtio_blk *vblk = vdev->priv; |
|
|
|
/* Ensure we don't receive any more interrupts */ |
|
vdev->config->reset(vdev); |
|
|
|
/* Make sure no work handler is accessing the device. */ |
|
flush_work(&vblk->config_work); |
|
|
|
blk_mq_quiesce_queue(vblk->disk->queue); |
|
|
|
vdev->config->del_vqs(vdev); |
|
kfree(vblk->vqs); |
|
|
|
return 0; |
|
} |
|
|
|
static int virtblk_restore(struct virtio_device *vdev) |
|
{ |
|
struct virtio_blk *vblk = vdev->priv; |
|
int ret; |
|
|
|
ret = init_vq(vdev->priv); |
|
if (ret) |
|
return ret; |
|
|
|
virtio_device_ready(vdev); |
|
|
|
blk_mq_unquiesce_queue(vblk->disk->queue); |
|
return 0; |
|
} |
|
#endif |
|
|
|
static const struct virtio_device_id id_table[] = { |
|
{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, |
|
{ 0 }, |
|
}; |
|
|
|
static unsigned int features_legacy[] = { |
|
VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, |
|
VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, |
|
VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, |
|
VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, |
|
} |
|
; |
|
static unsigned int features[] = { |
|
VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, |
|
VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, |
|
VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, |
|
VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, |
|
}; |
|
|
|
static struct virtio_driver virtio_blk = { |
|
.feature_table = features, |
|
.feature_table_size = ARRAY_SIZE(features), |
|
.feature_table_legacy = features_legacy, |
|
.feature_table_size_legacy = ARRAY_SIZE(features_legacy), |
|
.driver.name = KBUILD_MODNAME, |
|
.driver.owner = THIS_MODULE, |
|
.id_table = id_table, |
|
.probe = virtblk_probe, |
|
.remove = virtblk_remove, |
|
.config_changed = virtblk_config_changed, |
|
#ifdef CONFIG_PM_SLEEP |
|
.freeze = virtblk_freeze, |
|
.restore = virtblk_restore, |
|
#endif |
|
}; |
|
|
|
static int __init init(void) |
|
{ |
|
int error; |
|
|
|
virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); |
|
if (!virtblk_wq) |
|
return -ENOMEM; |
|
|
|
major = register_blkdev(0, "virtblk"); |
|
if (major < 0) { |
|
error = major; |
|
goto out_destroy_workqueue; |
|
} |
|
|
|
error = register_virtio_driver(&virtio_blk); |
|
if (error) |
|
goto out_unregister_blkdev; |
|
return 0; |
|
|
|
out_unregister_blkdev: |
|
unregister_blkdev(major, "virtblk"); |
|
out_destroy_workqueue: |
|
destroy_workqueue(virtblk_wq); |
|
return error; |
|
} |
|
|
|
static void __exit fini(void) |
|
{ |
|
unregister_virtio_driver(&virtio_blk); |
|
unregister_blkdev(major, "virtblk"); |
|
destroy_workqueue(virtblk_wq); |
|
} |
|
module_init(init); |
|
module_exit(fini); |
|
|
|
MODULE_DEVICE_TABLE(virtio, id_table); |
|
MODULE_DESCRIPTION("Virtio block driver"); |
|
MODULE_LICENSE("GPL");
|
|
|