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https://github.com/torvalds/linux.git
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62952cc5bc
The discard_alignment queue limit is named a bit misleading means the
offset into the block device at which the discard granularity starts.
On the other hand the discard_sector_alignment from the virtio 1.1 looks
similar to what Linux uses as discard granularity (even if not very well
described):
"discard_sector_alignment can be used by OS when splitting a request
based on alignment. "
And at least qemu does set it to the discard granularity.
So stop setting the discard_alignment and use the virtio
discard_sector_alignment to set the discard granularity.
Fixes: 1f23816b8e
("virtio_blk: add discard and write zeroes support")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220418045314.360785-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
1060 lines
26 KiB
C
1060 lines
26 KiB
C
// 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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#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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/* 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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#ifdef CONFIG_ARCH_NO_SG_CHAIN
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#define VIRTIO_BLK_INLINE_SG_CNT 0
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#else
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#define VIRTIO_BLK_INLINE_SG_CNT 2
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#endif
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static unsigned int num_request_queues;
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module_param(num_request_queues, uint, 0644);
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MODULE_PARM_DESC(num_request_queues,
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"Limit the number of request queues to use for blk device. "
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"0 for no limit. "
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"Values > nr_cpu_ids truncated to nr_cpu_ids.");
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static int major;
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static DEFINE_IDA(vd_index_ida);
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static struct workqueue_struct *virtblk_wq;
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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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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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/* The disk structure for the kernel. */
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struct gendisk *disk;
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/* Block layer tags. */
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struct blk_mq_tag_set tag_set;
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/* Process context for config space updates */
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struct work_struct config_work;
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/* Ida index - used to track minor number allocations. */
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int index;
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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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struct virtblk_req {
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struct virtio_blk_outhdr out_hdr;
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u8 status;
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struct sg_table sg_table;
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struct scatterlist sg[];
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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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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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sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
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sgs[num_out++] = &hdr;
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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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sg_init_one(&status, &vbr->status, sizeof(vbr->status));
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sgs[num_out + num_in++] = &status;
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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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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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* 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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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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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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return 0;
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}
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static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr)
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{
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if (blk_rq_nr_phys_segments(req))
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sg_free_table_chained(&vbr->sg_table,
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VIRTIO_BLK_INLINE_SG_CNT);
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}
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static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req,
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struct virtblk_req *vbr)
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{
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int err;
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if (!blk_rq_nr_phys_segments(req))
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return 0;
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vbr->sg_table.sgl = vbr->sg;
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err = sg_alloc_table_chained(&vbr->sg_table,
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blk_rq_nr_phys_segments(req),
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vbr->sg_table.sgl,
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VIRTIO_BLK_INLINE_SG_CNT);
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if (unlikely(err))
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return -ENOMEM;
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return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl);
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}
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static void virtblk_cleanup_cmd(struct request *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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}
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static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
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struct request *req,
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struct virtblk_req *vbr)
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{
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bool unmap = false;
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u32 type;
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vbr->out_hdr.sector = 0;
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switch (req_op(req)) {
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case REQ_OP_READ:
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type = VIRTIO_BLK_T_IN;
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vbr->out_hdr.sector = cpu_to_virtio64(vdev,
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blk_rq_pos(req));
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break;
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case REQ_OP_WRITE:
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type = VIRTIO_BLK_T_OUT;
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vbr->out_hdr.sector = cpu_to_virtio64(vdev,
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blk_rq_pos(req));
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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(vdev, type);
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vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req));
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if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
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if (virtblk_setup_discard_write_zeroes(req, unmap))
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return BLK_STS_RESOURCE;
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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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virtblk_unmap_data(req, vbr);
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virtblk_cleanup_cmd(req);
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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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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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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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/* 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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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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int num;
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int qid = hctx->queue_num;
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bool notify = false;
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blk_status_t status;
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int err;
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status = virtblk_setup_cmd(vblk->vdev, req, vbr);
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if (unlikely(status))
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return status;
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blk_mq_start_request(req);
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num = virtblk_map_data(hctx, req, vbr);
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if (unlikely(num < 0)) {
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virtblk_cleanup_cmd(req);
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return BLK_STS_RESOURCE;
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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_table.sgl, 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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virtblk_unmap_data(req, vbr);
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virtblk_cleanup_cmd(req);
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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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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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/* 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_mq_alloc_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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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(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_mq_free_request(req);
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return err;
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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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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 void virtblk_free_disk(struct gendisk *disk)
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{
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struct virtio_blk *vblk = disk->private_data;
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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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static const struct block_device_operations virtblk_fops = {
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.owner = THIS_MODULE,
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.getgeo = virtblk_getgeo,
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.free_disk = virtblk_free_disk,
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};
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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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|
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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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|
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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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|
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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),
|
|
STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
|
|
|
|
dev_notice(&vdev->dev,
|
|
"[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
|
|
vblk->disk->disk_name,
|
|
resize ? "new size: " : "",
|
|
nblocks,
|
|
queue_logical_block_size(q),
|
|
cap_str_10,
|
|
cap_str_2);
|
|
|
|
set_capacity_and_notify(vblk->disk, capacity);
|
|
}
|
|
|
|
static void virtblk_config_changed_work(struct work_struct *work)
|
|
{
|
|
struct virtio_blk *vblk =
|
|
container_of(work, struct virtio_blk, config_work);
|
|
|
|
virtblk_update_capacity(vblk, true);
|
|
}
|
|
|
|
static void virtblk_config_changed(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_blk *vblk = vdev->priv;
|
|
|
|
queue_work(virtblk_wq, &vblk->config_work);
|
|
}
|
|
|
|
static int init_vq(struct virtio_blk *vblk)
|
|
{
|
|
int err;
|
|
int i;
|
|
vq_callback_t **callbacks;
|
|
const char **names;
|
|
struct virtqueue **vqs;
|
|
unsigned short num_vqs;
|
|
struct virtio_device *vdev = vblk->vdev;
|
|
struct irq_affinity desc = { 0, };
|
|
|
|
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
|
|
struct virtio_blk_config, num_queues,
|
|
&num_vqs);
|
|
if (err)
|
|
num_vqs = 1;
|
|
if (!err && !num_vqs) {
|
|
dev_err(&vdev->dev, "MQ advertised but zero queues reported\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
num_vqs = min_t(unsigned int,
|
|
min_not_zero(num_request_queues, nr_cpu_ids),
|
|
num_vqs);
|
|
|
|
vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
|
|
if (!vblk->vqs)
|
|
return -ENOMEM;
|
|
|
|
names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
|
|
callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
|
|
vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
|
|
if (!names || !callbacks || !vqs) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < num_vqs; i++) {
|
|
callbacks[i] = virtblk_done;
|
|
snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
|
|
names[i] = vblk->vqs[i].name;
|
|
}
|
|
|
|
/* Discover virtqueues and write information to configuration. */
|
|
err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc);
|
|
if (err)
|
|
goto out;
|
|
|
|
for (i = 0; i < num_vqs; i++) {
|
|
spin_lock_init(&vblk->vqs[i].lock);
|
|
vblk->vqs[i].vq = vqs[i];
|
|
}
|
|
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 sysfs_emit(buf, "%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_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,
|
|
.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);
|
|
|
|
vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
|
|
if (!vblk) {
|
|
err = -ENOMEM;
|
|
goto out_free_index;
|
|
}
|
|
|
|
mutex_init(&vblk->vdev_mutex);
|
|
|
|
vblk->vdev = vdev;
|
|
|
|
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) * VIRTIO_BLK_INLINE_SG_CNT;
|
|
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->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, sg_elems);
|
|
|
|
/* 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) {
|
|
err = blk_validate_block_size(blk_size);
|
|
if (err) {
|
|
dev_err(&vdev->dev,
|
|
"virtio_blk: invalid block size: 0x%x\n",
|
|
blk_size);
|
|
goto out_cleanup_disk;
|
|
}
|
|
|
|
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)) {
|
|
virtio_cread(vdev, struct virtio_blk_config,
|
|
discard_sector_alignment, &v);
|
|
if (v)
|
|
q->limits.discard_granularity = v << SECTOR_SHIFT;
|
|
else
|
|
q->limits.discard_granularity = blk_size;
|
|
|
|
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);
|
|
|
|
/*
|
|
* max_discard_seg == 0 is out of spec but we always
|
|
* handled it.
|
|
*/
|
|
if (!v)
|
|
v = sg_elems;
|
|
blk_queue_max_discard_segments(q,
|
|
min(v, MAX_DISCARD_SEGMENTS));
|
|
}
|
|
|
|
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_queue(vblk->disk->queue);
|
|
blk_mq_free_tag_set(&vblk->tag_set);
|
|
|
|
mutex_lock(&vblk->vdev_mutex);
|
|
|
|
/* Stop all the virtqueues. */
|
|
virtio_reset_device(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);
|
|
|
|
put_disk(vblk->disk);
|
|
}
|
|
|
|
#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 */
|
|
virtio_reset_device(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 virtio_blk_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 virtio_blk_fini(void)
|
|
{
|
|
unregister_virtio_driver(&virtio_blk);
|
|
unregister_blkdev(major, "virtblk");
|
|
destroy_workqueue(virtblk_wq);
|
|
}
|
|
module_init(virtio_blk_init);
|
|
module_exit(virtio_blk_fini);
|
|
|
|
MODULE_DEVICE_TABLE(virtio, id_table);
|
|
MODULE_DESCRIPTION("Virtio block driver");
|
|
MODULE_LICENSE("GPL");
|