![Rusty Russell](/assets/img/avatar_default.png)
It's simply a flag as to whether we have data now, so make it an explicit function parameter rather than a member of struct virtblk_req. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Asias He <asias@redhat.com>
1006 lines
24 KiB
C
1006 lines
24 KiB
C
//#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/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 <scsi/scsi_cmnd.h>
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#include <linux/idr.h>
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#define PART_BITS 4
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static bool use_bio;
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module_param(use_bio, bool, S_IRUGO);
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static int major;
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static DEFINE_IDA(vd_index_ida);
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struct workqueue_struct *virtblk_wq;
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struct virtio_blk
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{
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struct virtio_device *vdev;
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struct virtqueue *vq;
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wait_queue_head_t queue_wait;
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/* The disk structure for the kernel. */
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struct gendisk *disk;
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mempool_t *pool;
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/* Process context for config space updates */
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struct work_struct config_work;
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/* Lock for config space updates */
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struct mutex config_lock;
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/* enable config space updates */
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bool config_enable;
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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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/* Ida index - used to track minor number allocations. */
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int index;
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/* Scatterlist: can be too big for stack. */
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struct scatterlist sg[/*sg_elems*/];
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};
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struct virtblk_req
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{
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struct request *req;
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struct bio *bio;
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struct virtio_blk_outhdr out_hdr;
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struct virtio_scsi_inhdr in_hdr;
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struct work_struct work;
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struct virtio_blk *vblk;
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int flags;
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u8 status;
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struct scatterlist sg[];
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};
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enum {
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VBLK_IS_FLUSH = 1,
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VBLK_REQ_FLUSH = 2,
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VBLK_REQ_DATA = 4,
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VBLK_REQ_FUA = 8,
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};
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static inline int virtblk_result(struct virtblk_req *vbr)
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{
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switch (vbr->status) {
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case VIRTIO_BLK_S_OK:
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return 0;
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case VIRTIO_BLK_S_UNSUPP:
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return -ENOTTY;
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default:
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return -EIO;
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}
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}
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static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk,
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gfp_t gfp_mask)
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{
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struct virtblk_req *vbr;
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vbr = mempool_alloc(vblk->pool, gfp_mask);
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if (!vbr)
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return NULL;
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vbr->vblk = vblk;
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if (use_bio)
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sg_init_table(vbr->sg, vblk->sg_elems);
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return vbr;
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}
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static int __virtblk_add_req(struct virtqueue *vq,
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struct virtblk_req *vbr,
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struct scatterlist *data_sg,
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bool have_data)
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{
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struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6];
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unsigned int num_out = 0, num_in = 0;
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int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT;
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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 this is a packet command we need a couple of additional headers.
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* Behind the normal outhdr we put a segment with the scsi command
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* block, and before the normal inhdr we put the sense data and the
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* inhdr with additional status information.
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*/
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if (type == VIRTIO_BLK_T_SCSI_CMD) {
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sg_init_one(&cmd, vbr->req->cmd, vbr->req->cmd_len);
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sgs[num_out++] = &cmd;
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}
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if (have_data) {
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if (vbr->out_hdr.type & 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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if (type == VIRTIO_BLK_T_SCSI_CMD) {
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sg_init_one(&sense, vbr->req->sense, SCSI_SENSE_BUFFERSIZE);
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sgs[num_out + num_in++] = &sense;
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sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr));
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sgs[num_out + num_in++] = &inhdr;
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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 void virtblk_add_req(struct virtblk_req *vbr, bool have_data)
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{
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struct virtio_blk *vblk = vbr->vblk;
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DEFINE_WAIT(wait);
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int ret;
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spin_lock_irq(vblk->disk->queue->queue_lock);
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while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr, vbr->sg,
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have_data)) < 0)) {
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prepare_to_wait_exclusive(&vblk->queue_wait, &wait,
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TASK_UNINTERRUPTIBLE);
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spin_unlock_irq(vblk->disk->queue->queue_lock);
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io_schedule();
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spin_lock_irq(vblk->disk->queue->queue_lock);
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finish_wait(&vblk->queue_wait, &wait);
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}
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virtqueue_kick(vblk->vq);
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spin_unlock_irq(vblk->disk->queue->queue_lock);
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}
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static void virtblk_bio_send_flush(struct virtblk_req *vbr)
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{
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vbr->flags |= VBLK_IS_FLUSH;
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vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
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vbr->out_hdr.sector = 0;
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vbr->out_hdr.ioprio = 0;
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virtblk_add_req(vbr, false);
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}
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static void virtblk_bio_send_data(struct virtblk_req *vbr)
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{
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struct virtio_blk *vblk = vbr->vblk;
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struct bio *bio = vbr->bio;
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bool have_data;
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vbr->flags &= ~VBLK_IS_FLUSH;
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vbr->out_hdr.type = 0;
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vbr->out_hdr.sector = bio->bi_sector;
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vbr->out_hdr.ioprio = bio_prio(bio);
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if (blk_bio_map_sg(vblk->disk->queue, bio, vbr->sg)) {
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have_data = true;
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if (bio->bi_rw & REQ_WRITE)
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vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
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else
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vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
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} else
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have_data = false;
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virtblk_add_req(vbr, have_data);
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}
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static void virtblk_bio_send_data_work(struct work_struct *work)
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{
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struct virtblk_req *vbr;
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vbr = container_of(work, struct virtblk_req, work);
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virtblk_bio_send_data(vbr);
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}
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static void virtblk_bio_send_flush_work(struct work_struct *work)
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{
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struct virtblk_req *vbr;
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vbr = container_of(work, struct virtblk_req, work);
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virtblk_bio_send_flush(vbr);
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}
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static inline void virtblk_request_done(struct virtblk_req *vbr)
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{
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struct virtio_blk *vblk = vbr->vblk;
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struct request *req = vbr->req;
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int error = virtblk_result(vbr);
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if (req->cmd_type == REQ_TYPE_BLOCK_PC) {
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req->resid_len = vbr->in_hdr.residual;
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req->sense_len = vbr->in_hdr.sense_len;
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req->errors = vbr->in_hdr.errors;
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} else if (req->cmd_type == REQ_TYPE_SPECIAL) {
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req->errors = (error != 0);
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}
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__blk_end_request_all(req, error);
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mempool_free(vbr, vblk->pool);
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}
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static inline void virtblk_bio_flush_done(struct virtblk_req *vbr)
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{
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struct virtio_blk *vblk = vbr->vblk;
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if (vbr->flags & VBLK_REQ_DATA) {
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/* Send out the actual write data */
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INIT_WORK(&vbr->work, virtblk_bio_send_data_work);
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queue_work(virtblk_wq, &vbr->work);
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} else {
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bio_endio(vbr->bio, virtblk_result(vbr));
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mempool_free(vbr, vblk->pool);
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}
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}
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static inline void virtblk_bio_data_done(struct virtblk_req *vbr)
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{
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struct virtio_blk *vblk = vbr->vblk;
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if (unlikely(vbr->flags & VBLK_REQ_FUA)) {
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/* Send out a flush before end the bio */
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vbr->flags &= ~VBLK_REQ_DATA;
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INIT_WORK(&vbr->work, virtblk_bio_send_flush_work);
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queue_work(virtblk_wq, &vbr->work);
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} else {
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bio_endio(vbr->bio, virtblk_result(vbr));
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mempool_free(vbr, vblk->pool);
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}
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}
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static inline void virtblk_bio_done(struct virtblk_req *vbr)
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{
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if (unlikely(vbr->flags & VBLK_IS_FLUSH))
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virtblk_bio_flush_done(vbr);
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else
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virtblk_bio_data_done(vbr);
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}
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static void virtblk_done(struct virtqueue *vq)
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{
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struct virtio_blk *vblk = vq->vdev->priv;
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bool bio_done = false, req_done = false;
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struct virtblk_req *vbr;
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unsigned long flags;
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unsigned int len;
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spin_lock_irqsave(vblk->disk->queue->queue_lock, flags);
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do {
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virtqueue_disable_cb(vq);
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while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) {
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if (vbr->bio) {
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virtblk_bio_done(vbr);
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bio_done = true;
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} else {
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virtblk_request_done(vbr);
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req_done = true;
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}
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}
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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_start_queue(vblk->disk->queue);
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spin_unlock_irqrestore(vblk->disk->queue->queue_lock, flags);
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if (bio_done)
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wake_up(&vblk->queue_wait);
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}
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static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
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struct request *req)
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{
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unsigned int num;
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struct virtblk_req *vbr;
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vbr = virtblk_alloc_req(vblk, GFP_ATOMIC);
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if (!vbr)
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/* When another request finishes we'll try again. */
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return false;
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vbr->req = req;
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vbr->bio = NULL;
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if (req->cmd_flags & REQ_FLUSH) {
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vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
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vbr->out_hdr.sector = 0;
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vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
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} else {
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switch (req->cmd_type) {
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case REQ_TYPE_FS:
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vbr->out_hdr.type = 0;
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vbr->out_hdr.sector = blk_rq_pos(vbr->req);
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vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
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break;
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case REQ_TYPE_BLOCK_PC:
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vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
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vbr->out_hdr.sector = 0;
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vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
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break;
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case REQ_TYPE_SPECIAL:
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vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID;
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vbr->out_hdr.sector = 0;
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vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
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break;
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default:
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/* We don't put anything else in the queue. */
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BUG();
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}
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}
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num = blk_rq_map_sg(q, vbr->req, vblk->sg);
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if (num) {
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if (rq_data_dir(vbr->req) == WRITE)
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vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
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else
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vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
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}
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if (__virtblk_add_req(vblk->vq, vbr, vblk->sg, num) < 0) {
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mempool_free(vbr, vblk->pool);
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return false;
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}
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return true;
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}
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static void virtblk_request(struct request_queue *q)
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{
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struct virtio_blk *vblk = q->queuedata;
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struct request *req;
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unsigned int issued = 0;
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while ((req = blk_peek_request(q)) != NULL) {
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BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
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/* If this request fails, stop queue and wait for something to
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finish to restart it. */
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if (!do_req(q, vblk, req)) {
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blk_stop_queue(q);
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break;
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}
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blk_start_request(req);
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issued++;
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}
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if (issued)
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virtqueue_kick(vblk->vq);
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}
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static void virtblk_make_request(struct request_queue *q, struct bio *bio)
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{
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struct virtio_blk *vblk = q->queuedata;
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struct virtblk_req *vbr;
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BUG_ON(bio->bi_phys_segments + 2 > vblk->sg_elems);
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vbr = virtblk_alloc_req(vblk, GFP_NOIO);
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if (!vbr) {
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bio_endio(bio, -ENOMEM);
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return;
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}
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vbr->bio = bio;
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vbr->flags = 0;
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if (bio->bi_rw & REQ_FLUSH)
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vbr->flags |= VBLK_REQ_FLUSH;
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if (bio->bi_rw & REQ_FUA)
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vbr->flags |= VBLK_REQ_FUA;
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if (bio->bi_size)
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vbr->flags |= VBLK_REQ_DATA;
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if (unlikely(vbr->flags & VBLK_REQ_FLUSH))
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virtblk_bio_send_flush(vbr);
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else
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virtblk_bio_send_data(vbr);
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}
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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 *req;
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struct bio *bio;
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int err;
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bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,
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GFP_KERNEL);
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if (IS_ERR(bio))
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return PTR_ERR(bio);
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req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);
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if (IS_ERR(req)) {
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bio_put(bio);
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return PTR_ERR(req);
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}
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req->cmd_type = REQ_TYPE_SPECIAL;
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err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
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blk_put_request(req);
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return err;
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}
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static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
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unsigned int cmd, unsigned long data)
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{
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struct gendisk *disk = bdev->bd_disk;
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struct virtio_blk *vblk = disk->private_data;
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/*
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* Only allow the generic SCSI ioctls if the host can support it.
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*/
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if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
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return -ENOTTY;
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return scsi_cmd_blk_ioctl(bdev, mode, cmd,
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(void __user *)data);
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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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struct virtio_blk_geometry vgeo;
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int err;
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/* see if the host passed in geometry config */
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err = virtio_config_val(vblk->vdev, VIRTIO_BLK_F_GEOMETRY,
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offsetof(struct virtio_blk_config, geometry),
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&vgeo);
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if (!err) {
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geo->heads = vgeo.heads;
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geo->sectors = vgeo.sectors;
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geo->cylinders = vgeo.cylinders;
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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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return 0;
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}
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static const struct block_device_operations virtblk_fops = {
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.ioctl = virtblk_ioctl,
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.owner = THIS_MODULE,
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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 virtblk_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';
|
|
err = virtblk_get_id(disk, buf);
|
|
if (!err)
|
|
return strlen(buf);
|
|
|
|
if (err == -EIO) /* Unsupported? Make it empty. */
|
|
return 0;
|
|
|
|
return err;
|
|
}
|
|
DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
|
|
|
|
static void virtblk_config_changed_work(struct work_struct *work)
|
|
{
|
|
struct virtio_blk *vblk =
|
|
container_of(work, struct virtio_blk, config_work);
|
|
struct virtio_device *vdev = vblk->vdev;
|
|
struct request_queue *q = vblk->disk->queue;
|
|
char cap_str_2[10], cap_str_10[10];
|
|
char *envp[] = { "RESIZE=1", NULL };
|
|
u64 capacity, size;
|
|
|
|
mutex_lock(&vblk->config_lock);
|
|
if (!vblk->config_enable)
|
|
goto done;
|
|
|
|
/* Host must always specify the capacity. */
|
|
vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
|
|
&capacity, sizeof(capacity));
|
|
|
|
/* If capacity is too big, truncate with warning. */
|
|
if ((sector_t)capacity != capacity) {
|
|
dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
|
|
(unsigned long long)capacity);
|
|
capacity = (sector_t)-1;
|
|
}
|
|
|
|
size = capacity * queue_logical_block_size(q);
|
|
string_get_size(size, STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
|
|
string_get_size(size, STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
|
|
|
|
dev_notice(&vdev->dev,
|
|
"new size: %llu %d-byte logical blocks (%s/%s)\n",
|
|
(unsigned long long)capacity,
|
|
queue_logical_block_size(q),
|
|
cap_str_10, cap_str_2);
|
|
|
|
set_capacity(vblk->disk, capacity);
|
|
revalidate_disk(vblk->disk);
|
|
kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
|
|
done:
|
|
mutex_unlock(&vblk->config_lock);
|
|
}
|
|
|
|
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 = 0;
|
|
|
|
/* We expect one virtqueue, for output. */
|
|
vblk->vq = virtio_find_single_vq(vblk->vdev, virtblk_done, "requests");
|
|
if (IS_ERR(vblk->vq))
|
|
err = PTR_ERR(vblk->vq);
|
|
|
|
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_config_val(vdev, VIRTIO_BLK_F_CONFIG_WCE,
|
|
offsetof(struct virtio_blk_config, wce),
|
|
&writeback);
|
|
if (err)
|
|
writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE);
|
|
|
|
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;
|
|
|
|
if (writeback)
|
|
blk_queue_flush(vblk->disk->queue, REQ_FLUSH);
|
|
else
|
|
blk_queue_flush(vblk->disk->queue, 0);
|
|
|
|
revalidate_disk(vblk->disk);
|
|
}
|
|
|
|
static const char *const virtblk_cache_types[] = {
|
|
"write through", "write back"
|
|
};
|
|
|
|
static ssize_t
|
|
virtblk_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;
|
|
u8 writeback;
|
|
|
|
BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
|
|
for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; )
|
|
if (sysfs_streq(buf, virtblk_cache_types[i]))
|
|
break;
|
|
|
|
if (i < 0)
|
|
return -EINVAL;
|
|
|
|
writeback = i;
|
|
vdev->config->set(vdev,
|
|
offsetof(struct virtio_blk_config, wce),
|
|
&writeback, sizeof(writeback));
|
|
|
|
virtblk_update_cache_mode(vdev);
|
|
return count;
|
|
}
|
|
|
|
static ssize_t
|
|
virtblk_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 const struct device_attribute dev_attr_cache_type_ro =
|
|
__ATTR(cache_type, S_IRUGO,
|
|
virtblk_cache_type_show, NULL);
|
|
static const struct device_attribute dev_attr_cache_type_rw =
|
|
__ATTR(cache_type, S_IRUGO|S_IWUSR,
|
|
virtblk_cache_type_show, virtblk_cache_type_store);
|
|
|
|
static int virtblk_probe(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_blk *vblk;
|
|
struct request_queue *q;
|
|
int err, index;
|
|
int pool_size;
|
|
|
|
u64 cap;
|
|
u32 v, blk_size, sg_elems, opt_io_size;
|
|
u16 min_io_size;
|
|
u8 physical_block_exp, alignment_offset;
|
|
|
|
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_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
|
|
offsetof(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;
|
|
|
|
/* We need an extra sg elements at head and tail. */
|
|
sg_elems += 2;
|
|
vdev->priv = vblk = kmalloc(sizeof(*vblk) +
|
|
sizeof(vblk->sg[0]) * sg_elems, GFP_KERNEL);
|
|
if (!vblk) {
|
|
err = -ENOMEM;
|
|
goto out_free_index;
|
|
}
|
|
|
|
init_waitqueue_head(&vblk->queue_wait);
|
|
vblk->vdev = vdev;
|
|
vblk->sg_elems = sg_elems;
|
|
sg_init_table(vblk->sg, vblk->sg_elems);
|
|
mutex_init(&vblk->config_lock);
|
|
|
|
INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
|
|
vblk->config_enable = true;
|
|
|
|
err = init_vq(vblk);
|
|
if (err)
|
|
goto out_free_vblk;
|
|
|
|
pool_size = sizeof(struct virtblk_req);
|
|
if (use_bio)
|
|
pool_size += sizeof(struct scatterlist) * sg_elems;
|
|
vblk->pool = mempool_create_kmalloc_pool(1, pool_size);
|
|
if (!vblk->pool) {
|
|
err = -ENOMEM;
|
|
goto out_free_vq;
|
|
}
|
|
|
|
/* FIXME: How many partitions? How long is a piece of string? */
|
|
vblk->disk = alloc_disk(1 << PART_BITS);
|
|
if (!vblk->disk) {
|
|
err = -ENOMEM;
|
|
goto out_mempool;
|
|
}
|
|
|
|
q = vblk->disk->queue = blk_init_queue(virtblk_request, NULL);
|
|
if (!q) {
|
|
err = -ENOMEM;
|
|
goto out_put_disk;
|
|
}
|
|
|
|
if (use_bio)
|
|
blk_queue_make_request(q, virtblk_make_request);
|
|
q->queuedata = vblk;
|
|
|
|
virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
|
|
|
|
vblk->disk->major = major;
|
|
vblk->disk->first_minor = index_to_minor(index);
|
|
vblk->disk->private_data = vblk;
|
|
vblk->disk->fops = &virtblk_fops;
|
|
vblk->disk->driverfs_dev = &vdev->dev;
|
|
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);
|
|
|
|
/* Host must always specify the capacity. */
|
|
vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
|
|
&cap, sizeof(cap));
|
|
|
|
/* If capacity is too big, truncate with warning. */
|
|
if ((sector_t)cap != cap) {
|
|
dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
|
|
(unsigned long long)cap);
|
|
cap = (sector_t)-1;
|
|
}
|
|
set_capacity(vblk->disk, cap);
|
|
|
|
/* We can handle whatever the host told us to handle. */
|
|
blk_queue_max_segments(q, vblk->sg_elems-2);
|
|
|
|
/* No need to bounce any requests */
|
|
blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
|
|
|
|
/* No real sector limit. */
|
|
blk_queue_max_hw_sectors(q, -1U);
|
|
|
|
/* Host can optionally specify maximum segment size and number of
|
|
* segments. */
|
|
err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
|
|
offsetof(struct virtio_blk_config, size_max),
|
|
&v);
|
|
if (!err)
|
|
blk_queue_max_segment_size(q, v);
|
|
else
|
|
blk_queue_max_segment_size(q, -1U);
|
|
|
|
/* Host can optionally specify the block size of the device */
|
|
err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE,
|
|
offsetof(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_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
|
|
offsetof(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_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
|
|
offsetof(struct virtio_blk_config, alignment_offset),
|
|
&alignment_offset);
|
|
if (!err && alignment_offset)
|
|
blk_queue_alignment_offset(q, blk_size * alignment_offset);
|
|
|
|
err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
|
|
offsetof(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_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY,
|
|
offsetof(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);
|
|
|
|
add_disk(vblk->disk);
|
|
err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
|
|
if (err)
|
|
goto out_del_disk;
|
|
|
|
if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
|
|
err = device_create_file(disk_to_dev(vblk->disk),
|
|
&dev_attr_cache_type_rw);
|
|
else
|
|
err = device_create_file(disk_to_dev(vblk->disk),
|
|
&dev_attr_cache_type_ro);
|
|
if (err)
|
|
goto out_del_disk;
|
|
return 0;
|
|
|
|
out_del_disk:
|
|
del_gendisk(vblk->disk);
|
|
blk_cleanup_queue(vblk->disk->queue);
|
|
out_put_disk:
|
|
put_disk(vblk->disk);
|
|
out_mempool:
|
|
mempool_destroy(vblk->pool);
|
|
out_free_vq:
|
|
vdev->config->del_vqs(vdev);
|
|
out_free_vblk:
|
|
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;
|
|
int index = vblk->index;
|
|
int refc;
|
|
|
|
/* Prevent config work handler from accessing the device. */
|
|
mutex_lock(&vblk->config_lock);
|
|
vblk->config_enable = false;
|
|
mutex_unlock(&vblk->config_lock);
|
|
|
|
del_gendisk(vblk->disk);
|
|
blk_cleanup_queue(vblk->disk->queue);
|
|
|
|
/* Stop all the virtqueues. */
|
|
vdev->config->reset(vdev);
|
|
|
|
flush_work(&vblk->config_work);
|
|
|
|
refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
|
|
put_disk(vblk->disk);
|
|
mempool_destroy(vblk->pool);
|
|
vdev->config->del_vqs(vdev);
|
|
kfree(vblk);
|
|
|
|
/* Only free device id if we don't have any users */
|
|
if (refc == 1)
|
|
ida_simple_remove(&vd_index_ida, index);
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
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);
|
|
|
|
/* Prevent config work handler from accessing the device. */
|
|
mutex_lock(&vblk->config_lock);
|
|
vblk->config_enable = false;
|
|
mutex_unlock(&vblk->config_lock);
|
|
|
|
flush_work(&vblk->config_work);
|
|
|
|
spin_lock_irq(vblk->disk->queue->queue_lock);
|
|
blk_stop_queue(vblk->disk->queue);
|
|
spin_unlock_irq(vblk->disk->queue->queue_lock);
|
|
blk_sync_queue(vblk->disk->queue);
|
|
|
|
vdev->config->del_vqs(vdev);
|
|
return 0;
|
|
}
|
|
|
|
static int virtblk_restore(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_blk *vblk = vdev->priv;
|
|
int ret;
|
|
|
|
vblk->config_enable = true;
|
|
ret = init_vq(vdev->priv);
|
|
if (!ret) {
|
|
spin_lock_irq(vblk->disk->queue->queue_lock);
|
|
blk_start_queue(vblk->disk->queue);
|
|
spin_unlock_irq(vblk->disk->queue->queue_lock);
|
|
}
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
static const struct virtio_device_id id_table[] = {
|
|
{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
|
|
{ 0 },
|
|
};
|
|
|
|
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_SCSI,
|
|
VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE
|
|
};
|
|
|
|
static struct virtio_driver virtio_blk = {
|
|
.feature_table = features,
|
|
.feature_table_size = ARRAY_SIZE(features),
|
|
.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
|
|
.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_blkdev(major, "virtblk");
|
|
unregister_virtio_driver(&virtio_blk);
|
|
destroy_workqueue(virtblk_wq);
|
|
}
|
|
module_init(init);
|
|
module_exit(fini);
|
|
|
|
MODULE_DEVICE_TABLE(virtio, id_table);
|
|
MODULE_DESCRIPTION("Virtio block driver");
|
|
MODULE_LICENSE("GPL");
|