On Thu, Sep 15, 2022 at 09:48:21AM -0700, Sarthak Kukreti wrote: > From: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx> > > Adds support for provision requests. Provision requests act like > the inverse of discards. > > Signed-off-by: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx> > --- > drivers/block/virtio_blk.c | 48 +++++++++++++++++++++++++++++++++ > include/uapi/linux/virtio_blk.h | 9 +++++++ > 2 files changed, 57 insertions(+) Please send a VIRTIO spec patch too: https://github.com/oasis-tcs/virtio-spec#providing-feedback Stefan > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 30255fcaf181..eacc2bffe1d1 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -178,6 +178,39 @@ static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap) > return 0; > } > > +static int virtblk_setup_provision(struct request *req) > +{ > + 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; > + > + 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++; > + } > + > + 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)) > @@ -243,6 +276,9 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, > case REQ_OP_DRV_IN: > type = VIRTIO_BLK_T_GET_ID; > break; > + case REQ_OP_PROVISION: > + type = VIRTIO_BLK_T_PROVISION; > + break; > default: > WARN_ON_ONCE(1); > return BLK_STS_IOERR; > @@ -256,6 +292,11 @@ static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev, > return BLK_STS_RESOURCE; > } > > + if (type == VIRTIO_BLK_T_PROVISION) { > + if (virtblk_setup_provision(req)) > + return BLK_STS_RESOURCE; > + } > + > return 0; > } > > @@ -1075,6 +1116,12 @@ static int virtblk_probe(struct virtio_device *vdev) > blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); > } > > + if (virtio_has_feature(vdev, VIRTIO_BLK_F_PROVISION)) { > + virtio_cread(vdev, struct virtio_blk_config, > + max_provision_sectors, &v); > + q->limits.max_provision_sectors = v ? v : UINT_MAX; > + } > + > virtblk_update_capacity(vblk, false); > virtio_device_ready(vdev); > > @@ -1177,6 +1224,7 @@ static unsigned int features[] = { > 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, > + VIRTIO_BLK_F_PROVISION, > }; > > static struct virtio_driver virtio_blk = { > diff --git a/include/uapi/linux/virtio_blk.h b/include/uapi/linux/virtio_blk.h > index d888f013d9ff..184f8cf6d185 100644 > --- a/include/uapi/linux/virtio_blk.h > +++ b/include/uapi/linux/virtio_blk.h > @@ -40,6 +40,7 @@ > #define VIRTIO_BLK_F_MQ 12 /* support more than one vq */ > #define VIRTIO_BLK_F_DISCARD 13 /* DISCARD is supported */ > #define VIRTIO_BLK_F_WRITE_ZEROES 14 /* WRITE ZEROES is supported */ > +#define VIRTIO_BLK_F_PROVISION 15 /* provision is supported */ > > /* Legacy feature bits */ > #ifndef VIRTIO_BLK_NO_LEGACY > @@ -120,6 +121,11 @@ struct virtio_blk_config { > */ > __u8 write_zeroes_may_unmap; > > + /* > + * The maximum number of sectors in a provision request. > + */ > + __virtio32 max_provision_sectors; > + > __u8 unused1[3]; > } __attribute__((packed)); > > @@ -155,6 +161,9 @@ struct virtio_blk_config { > /* Write zeroes command */ > #define VIRTIO_BLK_T_WRITE_ZEROES 13 > > +/* Provision command */ > +#define VIRTIO_BLK_T_PROVISION 14 > + > #ifndef VIRTIO_BLK_NO_LEGACY > /* Barrier before this op. */ > #define VIRTIO_BLK_T_BARRIER 0x80000000 > -- > 2.31.0 >
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