Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

[sfrench/cifs-2.6.git] / drivers / block / virtio_blk.c

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 912c4265e592dcc1c7603f78351f6becf4f55f54..b16a887bbd02a8b7715fb85a812c73f75a2d25fe 100644 (file)
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -18,6 +18,7 @@
 
 #define PART_BITS 4
 #define VQ_NAME_LEN 16
+#define MAX_DISCARD_SEGMENTS 256u
 
 static int major;
 static DEFINE_IDA(vd_index_ida);
@@ -172,10 +173,48 @@ static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
        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;
+
+       __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++;
+       }
+
+       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 inline void virtblk_request_done(struct request *req)
 {
        struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
 
+       if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
+               kfree(page_address(req->special_vec.bv_page) +
+                     req->special_vec.bv_offset);
+       }
+
        switch (req_op(req)) {
        case REQ_OP_SCSI_IN:
        case REQ_OP_SCSI_OUT:
@@ -239,6 +278,7 @@ static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
        int qid = hctx->queue_num;
        int err;
        bool notify = false;
+       bool unmap = false;
        u32 type;
 
        BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
@@ -251,6 +291,13 @@ static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
        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_SCSI_IN:
        case REQ_OP_SCSI_OUT:
                type = VIRTIO_BLK_T_SCSI_CMD;
@@ -270,6 +317,12 @@ static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
 
        blk_mq_start_request(req);
 
+       if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) {
+               err = virtblk_setup_discard_write_zeroes(req, unmap);
+               if (err)
+                       return BLK_STS_RESOURCE;
+       }
+
        num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
        if (num) {
                if (rq_data_dir(req) == WRITE)
@@ -817,6 +870,32 @@ static int virtblk_probe(struct virtio_device *vdev)
        if (!err && opt_io_size)
                blk_queue_io_opt(q, blk_size * opt_io_size);
 
+       if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
+               q->limits.discard_granularity = blk_size;
+
+               virtio_cread(vdev, struct virtio_blk_config,
+                            discard_sector_alignment, &v);
+               q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0;
+
+               virtio_cread(vdev, struct virtio_blk_config,
+                            max_discard_sectors, &v);
+               blk_queue_max_discard_sectors(q, v ? v : UINT_MAX);
+
+               virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
+                            &v);
+               blk_queue_max_discard_segments(q,
+                                              min_not_zero(v,
+                                                           MAX_DISCARD_SEGMENTS));
+
+               blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
+       }
+
+       if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
+               virtio_cread(vdev, struct virtio_blk_config,
+                            max_write_zeroes_sectors, &v);
+               blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX);
+       }
+
        virtblk_update_capacity(vblk, false);
        virtio_device_ready(vdev);
 
@@ -910,14 +989,14 @@ static unsigned int features_legacy[] = {
        VIRTIO_BLK_F_SCSI,
 #endif
        VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
-       VIRTIO_BLK_F_MQ,
+       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_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
 };
 
 static struct virtio_driver virtio_blk = {