Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Suwan Kim | 928 | 15.99% | 3 | 2.10% |
Christoph Hellwig | 878 | 15.13% | 32 | 22.38% |
Rusty Russell | 561 | 9.67% | 10 | 6.99% |
Ming Lei | 455 | 7.84% | 5 | 3.50% |
Max Gurtovoy | 393 | 6.77% | 2 | 1.40% |
Paolo Bonzini | 382 | 6.58% | 5 | 3.50% |
Changpeng Liu | 337 | 5.81% | 1 | 0.70% |
Michael S. Tsirkin | 201 | 3.46% | 16 | 11.19% |
Jens Axboe | 184 | 3.17% | 6 | 4.20% |
Stefan Hajnoczi | 175 | 3.02% | 4 | 2.80% |
Christian Bornträger | 170 | 2.93% | 5 | 3.50% |
Asias He | 167 | 2.88% | 4 | 2.80% |
Amit Shah | 162 | 2.79% | 2 | 1.40% |
Ren Mingxin | 143 | 2.46% | 1 | 0.70% |
Hannes Reinecke | 137 | 2.36% | 3 | 2.10% |
Ryan Harper | 128 | 2.21% | 2 | 1.40% |
john cooper | 67 | 1.15% | 1 | 0.70% |
Xie Yongji | 55 | 0.95% | 4 | 2.80% |
Shigeru Yoshida | 49 | 0.84% | 1 | 0.70% |
Jason (Hui) Wang | 23 | 0.40% | 1 | 0.70% |
Halil Pasic | 22 | 0.38% | 2 | 1.40% |
Minfei Huang | 18 | 0.31% | 1 | 0.70% |
Lei Ming | 14 | 0.24% | 1 | 0.70% |
Joerg Roedel | 14 | 0.24% | 1 | 0.70% |
Joseph Qi | 14 | 0.24% | 1 | 0.70% |
Shaohua Li | 13 | 0.22% | 1 | 0.70% |
SF Markus Elfring | 12 | 0.21% | 1 | 0.70% |
Heinz Graalfs | 11 | 0.19% | 1 | 0.70% |
Mike Snitzer | 10 | 0.17% | 1 | 0.70% |
Dongli Zhang | 10 | 0.17% | 1 | 0.70% |
Luis R. Rodriguez | 10 | 0.17% | 1 | 0.70% |
James Bottomley | 7 | 0.12% | 1 | 0.70% |
Hou Tao | 7 | 0.12% | 1 | 0.70% |
Dan J Williams | 6 | 0.10% | 1 | 0.70% |
Omar Sandoval | 5 | 0.09% | 1 | 0.70% |
Andy Shevchenko | 4 | 0.07% | 1 | 0.70% |
Randy Dunlap | 4 | 0.07% | 1 | 0.70% |
Tejun Heo | 4 | 0.07% | 2 | 1.40% |
Alexander Graf | 3 | 0.05% | 1 | 0.70% |
Martin K. Petersen | 3 | 0.05% | 2 | 1.40% |
Paul Gortmaker | 3 | 0.05% | 1 | 0.70% |
Sagi Grimberg | 2 | 0.03% | 1 | 0.70% |
Aaron Lu | 2 | 0.03% | 1 | 0.70% |
Jeremy Katz | 2 | 0.03% | 1 | 0.70% |
Eric Biggers | 1 | 0.02% | 1 | 0.70% |
Jonghwan Choi | 1 | 0.02% | 1 | 0.70% |
Márton Németh | 1 | 0.02% | 1 | 0.70% |
Colin Ian King | 1 | 0.02% | 1 | 0.70% |
Tian Tao | 1 | 0.02% | 1 | 0.70% |
Thomas Gleixner | 1 | 0.02% | 1 | 0.70% |
Ye Guojin | 1 | 0.02% | 1 | 0.70% |
Alexey Dobriyan | 1 | 0.02% | 1 | 0.70% |
Total | 5803 | 143 |
// SPDX-License-Identifier: GPL-2.0-only //#define DEBUG #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/blkdev.h> #include <linux/hdreg.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/interrupt.h> #include <linux/virtio.h> #include <linux/virtio_blk.h> #include <linux/scatterlist.h> #include <linux/string_helpers.h> #include <linux/idr.h> #include <linux/blk-mq.h> #include <linux/blk-mq-virtio.h> #include <linux/numa.h> #include <uapi/linux/virtio_ring.h> #define PART_BITS 4 #define VQ_NAME_LEN 16 #define MAX_DISCARD_SEGMENTS 256u /* The maximum number of sg elements that fit into a virtqueue */ #define VIRTIO_BLK_MAX_SG_ELEMS 32768 #ifdef CONFIG_ARCH_NO_SG_CHAIN #define VIRTIO_BLK_INLINE_SG_CNT 0 #else #define VIRTIO_BLK_INLINE_SG_CNT 2 #endif static unsigned int num_request_queues; module_param(num_request_queues, uint, 0644); MODULE_PARM_DESC(num_request_queues, "Limit the number of request queues to use for blk device. " "0 for no limit. " "Values > nr_cpu_ids truncated to nr_cpu_ids."); static unsigned int poll_queues; module_param(poll_queues, uint, 0644); MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O"); static int major; static DEFINE_IDA(vd_index_ida); static struct workqueue_struct *virtblk_wq; struct virtio_blk_vq { struct virtqueue *vq; spinlock_t lock; char name[VQ_NAME_LEN]; } ____cacheline_aligned_in_smp; struct virtio_blk { /* * This mutex must be held by anything that may run after * virtblk_remove() sets vblk->vdev to NULL. * * blk-mq, virtqueue processing, and sysfs attribute code paths are * shut down before vblk->vdev is set to NULL and therefore do not need * to hold this mutex. */ struct mutex vdev_mutex; struct virtio_device *vdev; /* The disk structure for the kernel. */ struct gendisk *disk; /* Block layer tags. */ struct blk_mq_tag_set tag_set; /* Process context for config space updates */ struct work_struct config_work; /* Ida index - used to track minor number allocations. */ int index; /* num of vqs */ int num_vqs; int io_queues[HCTX_MAX_TYPES]; struct virtio_blk_vq *vqs; }; struct virtblk_req { struct virtio_blk_outhdr out_hdr; u8 status; struct sg_table sg_table; struct scatterlist sg[]; }; static inline blk_status_t virtblk_result(struct virtblk_req *vbr) { switch (vbr->status) { case VIRTIO_BLK_S_OK: return BLK_STS_OK; case VIRTIO_BLK_S_UNSUPP: return BLK_STS_NOTSUPP; default: return BLK_STS_IOERR; } } static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx) { struct virtio_blk *vblk = hctx->queue->queuedata; struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; return vq; } static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr) { struct scatterlist hdr, status, *sgs[3]; unsigned int num_out = 0, num_in = 0; sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); sgs[num_out++] = &hdr; if (vbr->sg_table.nents) { if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) sgs[num_out++] = vbr->sg_table.sgl; else sgs[num_out + num_in++] = vbr->sg_table.sgl; } sg_init_one(&status, &vbr->status, sizeof(vbr->status)); sgs[num_out + num_in++] = &status; return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); } static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap) { unsigned short segments = blk_rq_nr_discard_segments(req); unsigned short n = 0; struct virtio_blk_discard_write_zeroes *range; struct bio *bio; u32 flags = 0; if (unmap) flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC); if (!range) return -ENOMEM; /* * Single max discard segment means multi-range discard isn't * supported, and block layer only runs contiguity merge like * normal RW request. So we can't reply on bio for retrieving * each range info. */ if (queue_max_discard_segments(req->q) == 1) { range[0].flags = cpu_to_le32(flags); range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req)); range[0].sector = cpu_to_le64(blk_rq_pos(req)); n = 1; } else { __rq_for_each_bio(bio, req) { u64 sector = bio->bi_iter.bi_sector; u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; range[n].flags = cpu_to_le32(flags); range[n].num_sectors = cpu_to_le32(num_sectors); range[n].sector = cpu_to_le64(sector); n++; } } WARN_ON_ONCE(n != segments); req->special_vec.bv_page = virt_to_page(range); req->special_vec.bv_offset = offset_in_page(range); req->special_vec.bv_len = sizeof(*range) * segments; req->rq_flags |= RQF_SPECIAL_PAYLOAD; return 0; } static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr) { if (blk_rq_nr_phys_segments(req)) sg_free_table_chained(&vbr->sg_table, VIRTIO_BLK_INLINE_SG_CNT); } static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req, struct virtblk_req *vbr) { int err; if (!blk_rq_nr_phys_segments(req)) return 0; vbr->sg_table.sgl = vbr->sg; err = sg_alloc_table_chained(&vbr->sg_table, blk_rq_nr_phys_segments(req), vbr->sg_table.sgl, VIRTIO_BLK_INLINE_SG_CNT); if (unlikely(err)) return -ENOMEM; return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl); } static void virtblk_cleanup_cmd(struct request *req) { if (req->rq_flags & RQF_SPECIAL_PAYLOAD) kfree(bvec_virt(&req->special_vec)); } static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, struct request *req, struct virtblk_req *vbr) { bool unmap = false; u32 type; vbr->out_hdr.sector = 0; switch (req_op(req)) { case REQ_OP_READ: type = VIRTIO_BLK_T_IN; vbr->out_hdr.sector = cpu_to_virtio64(vdev, blk_rq_pos(req)); break; case REQ_OP_WRITE: type = VIRTIO_BLK_T_OUT; vbr->out_hdr.sector = cpu_to_virtio64(vdev, blk_rq_pos(req)); break; case REQ_OP_FLUSH: type = VIRTIO_BLK_T_FLUSH; break; case REQ_OP_DISCARD: type = VIRTIO_BLK_T_DISCARD; break; case REQ_OP_WRITE_ZEROES: type = VIRTIO_BLK_T_WRITE_ZEROES; unmap = !(req->cmd_flags & REQ_NOUNMAP); break; case REQ_OP_DRV_IN: type = VIRTIO_BLK_T_GET_ID; break; default: WARN_ON_ONCE(1); return BLK_STS_IOERR; } vbr->out_hdr.type = cpu_to_virtio32(vdev, type); vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req)); if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) { if (virtblk_setup_discard_write_zeroes(req, unmap)) return BLK_STS_RESOURCE; } return 0; } static inline void virtblk_request_done(struct request *req) { struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); virtblk_unmap_data(req, vbr); virtblk_cleanup_cmd(req); blk_mq_end_request(req, virtblk_result(vbr)); } static void virtblk_done(struct virtqueue *vq) { struct virtio_blk *vblk = vq->vdev->priv; bool req_done = false; int qid = vq->index; struct virtblk_req *vbr; unsigned long flags; unsigned int len; spin_lock_irqsave(&vblk->vqs[qid].lock, flags); do { virtqueue_disable_cb(vq); while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { struct request *req = blk_mq_rq_from_pdu(vbr); if (likely(!blk_should_fake_timeout(req->q))) blk_mq_complete_request(req); req_done = true; } if (unlikely(virtqueue_is_broken(vq))) break; } while (!virtqueue_enable_cb(vq)); /* In case queue is stopped waiting for more buffers. */ if (req_done) blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); } static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) { struct virtio_blk *vblk = hctx->queue->queuedata; struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; bool kick; spin_lock_irq(&vq->lock); kick = virtqueue_kick_prepare(vq->vq); spin_unlock_irq(&vq->lock); if (kick) virtqueue_notify(vq->vq); } static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx, struct virtio_blk *vblk, struct request *req, struct virtblk_req *vbr) { blk_status_t status; status = virtblk_setup_cmd(vblk->vdev, req, vbr); if (unlikely(status)) return status; vbr->sg_table.nents = virtblk_map_data(hctx, req, vbr); if (unlikely(vbr->sg_table.nents < 0)) { virtblk_cleanup_cmd(req); return BLK_STS_RESOURCE; } blk_mq_start_request(req); return BLK_STS_OK; } static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { struct virtio_blk *vblk = hctx->queue->queuedata; struct request *req = bd->rq; struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); unsigned long flags; int qid = hctx->queue_num; bool notify = false; blk_status_t status; int err; status = virtblk_prep_rq(hctx, vblk, req, vbr); if (unlikely(status)) return status; spin_lock_irqsave(&vblk->vqs[qid].lock, flags); err = virtblk_add_req(vblk->vqs[qid].vq, vbr); if (err) { virtqueue_kick(vblk->vqs[qid].vq); /* Don't stop the queue if -ENOMEM: we may have failed to * bounce the buffer due to global resource outage. */ if (err == -ENOSPC) blk_mq_stop_hw_queue(hctx); spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); virtblk_unmap_data(req, vbr); virtblk_cleanup_cmd(req); switch (err) { case -ENOSPC: return BLK_STS_DEV_RESOURCE; case -ENOMEM: return BLK_STS_RESOURCE; default: return BLK_STS_IOERR; } } if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) notify = true; spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); if (notify) virtqueue_notify(vblk->vqs[qid].vq); return BLK_STS_OK; } static bool virtblk_prep_rq_batch(struct request *req) { struct virtio_blk *vblk = req->mq_hctx->queue->queuedata; struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); req->mq_hctx->tags->rqs[req->tag] = req; return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK; } static bool virtblk_add_req_batch(struct virtio_blk_vq *vq, struct request **rqlist) { unsigned long flags; int err; bool kick; spin_lock_irqsave(&vq->lock, flags); while (!rq_list_empty(*rqlist)) { struct request *req = rq_list_pop(rqlist); struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); err = virtblk_add_req(vq->vq, vbr); if (err) { virtblk_unmap_data(req, vbr); virtblk_cleanup_cmd(req); blk_mq_requeue_request(req, true); } } kick = virtqueue_kick_prepare(vq->vq); spin_unlock_irqrestore(&vq->lock, flags); return kick; } static void virtio_queue_rqs(struct request **rqlist) { struct request *req, *next, *prev = NULL; struct request *requeue_list = NULL; rq_list_for_each_safe(rqlist, req, next) { struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx); bool kick; if (!virtblk_prep_rq_batch(req)) { rq_list_move(rqlist, &requeue_list, req, prev); req = prev; if (!req) continue; } if (!next || req->mq_hctx != next->mq_hctx) { req->rq_next = NULL; kick = virtblk_add_req_batch(vq, rqlist); if (kick) virtqueue_notify(vq->vq); *rqlist = next; prev = NULL; } else prev = req; } *rqlist = requeue_list; } /* return id (s/n) string for *disk to *id_str */ static int virtblk_get_id(struct gendisk *disk, char *id_str) { struct virtio_blk *vblk = disk->private_data; struct request_queue *q = vblk->disk->queue; struct request *req; int err; req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); if (IS_ERR(req)) return PTR_ERR(req); err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); if (err) goto out; blk_execute_rq(req, false); err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req))); out: blk_mq_free_request(req); return err; } /* We provide getgeo only to please some old bootloader/partitioning tools */ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) { struct virtio_blk *vblk = bd->bd_disk->private_data; int ret = 0; mutex_lock(&vblk->vdev_mutex); if (!vblk->vdev) { ret = -ENXIO; goto out; } /* see if the host passed in geometry config */ if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { virtio_cread(vblk->vdev, struct virtio_blk_config, geometry.cylinders, &geo->cylinders); virtio_cread(vblk->vdev, struct virtio_blk_config, geometry.heads, &geo->heads); virtio_cread(vblk->vdev, struct virtio_blk_config, geometry.sectors, &geo->sectors); } else { /* some standard values, similar to sd */ geo->heads = 1 << 6; geo->sectors = 1 << 5; geo->cylinders = get_capacity(bd->bd_disk) >> 11; } out: mutex_unlock(&vblk->vdev_mutex); return ret; } static void virtblk_free_disk(struct gendisk *disk) { struct virtio_blk *vblk = disk->private_data; ida_simple_remove(&vd_index_ida, vblk->index); mutex_destroy(&vblk->vdev_mutex); kfree(vblk); } static const struct block_device_operations virtblk_fops = { .owner = THIS_MODULE, .getgeo = virtblk_getgeo, .free_disk = virtblk_free_disk, }; static int index_to_minor(int index) { return index << PART_BITS; } static int minor_to_index(int minor) { return minor >> PART_BITS; } static ssize_t serial_show(struct device *dev, struct device_attribute *attr, char *buf) { struct gendisk *disk = dev_to_disk(dev); int err; /* sysfs gives us a PAGE_SIZE buffer */ BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 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; } static DEVICE_ATTR_RO(serial); /* The queue's logical block size must be set before calling this */ static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) { struct virtio_device *vdev = vblk->vdev; struct request_queue *q = vblk->disk->queue; char cap_str_2[10], cap_str_10[10]; unsigned long long nblocks; u64 capacity; /* Host must always specify the capacity. */ virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); string_get_size(nblocks, queue_logical_block_size(q), 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; unsigned int num_poll_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); num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1); vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs; vblk->io_queues[HCTX_TYPE_READ] = 0; vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", vblk->io_queues[HCTX_TYPE_DEFAULT], vblk->io_queues[HCTX_TYPE_READ], vblk->io_queues[HCTX_TYPE_POLL]); 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 - num_poll_vqs; i++) { callbacks[i] = virtblk_done; snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i); names[i] = vblk->vqs[i].name; } for (; i < num_vqs; i++) { callbacks[i] = NULL; snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req_poll.%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; int i, qoff; for (i = 0, qoff = 0; i < set->nr_maps; i++) { struct blk_mq_queue_map *map = &set->map[i]; map->nr_queues = vblk->io_queues[i]; map->queue_offset = qoff; qoff += map->nr_queues; if (map->nr_queues == 0) continue; /* * Regular queues have interrupts and hence CPU affinity is * defined by the core virtio code, but polling queues have * no interrupts so we let the block layer assign CPU affinity. */ if (i == HCTX_TYPE_POLL) blk_mq_map_queues(&set->map[i]); else blk_mq_virtio_map_queues(&set->map[i], vblk->vdev, 0); } return 0; } static void virtblk_complete_batch(struct io_comp_batch *iob) { struct request *req; rq_list_for_each(&iob->req_list, req) { virtblk_unmap_data(req, blk_mq_rq_to_pdu(req)); virtblk_cleanup_cmd(req); } blk_mq_end_request_batch(iob); } static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) { struct virtio_blk *vblk = hctx->queue->queuedata; struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx); struct virtblk_req *vbr; unsigned long flags; unsigned int len; int found = 0; spin_lock_irqsave(&vq->lock, flags); while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) { struct request *req = blk_mq_rq_from_pdu(vbr); found++; if (!blk_mq_add_to_batch(req, iob, vbr->status, virtblk_complete_batch)) blk_mq_complete_request(req); } if (found) blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); spin_unlock_irqrestore(&vq->lock, flags); return found; } static const struct blk_mq_ops virtio_mq_ops = { .queue_rq = virtio_queue_rq, .queue_rqs = virtio_queue_rqs, .commit_rqs = virtio_commit_rqs, .complete = virtblk_request_done, .map_queues = virtblk_map_queues, .poll = virtblk_poll, }; 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; vblk->tag_set.nr_maps = 1; if (vblk->io_queues[HCTX_TYPE_POLL]) vblk->tag_set.nr_maps = 3; 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: put_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_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");
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