AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2025-03-11 23:27:42 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

virtio-blk: use virtqueue_add_sgs on req path

Browse Source 
(This is a respin of Paolo Bonzini's patch, but it calls
virtqueue_add_sgs() instead of his multi-part API).

This is similar to the previous patch, but a bit more radical
because the bio and req paths now share the buffer construction
code.  Because the req path doesn't use vbr->sg, however, we
need to add a couple of arguments to __virtblk_add_req.

We also need to teach __virtblk_add_req how to build SCSI command
requests.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Asias He <asias@redhat.com>
This commit is contained in:
Paolo Bonzini 2013-03-20 15:44:27 +10:30 committed by Rusty Russell
parent 8f39db9d37
commit 20af3cfd20
1 changed files with 33 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
drivers/block/virtio_blk.c
View File

@ -102,19 +102,40 @@ static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk,
}
static int __virtblk_add_req(struct virtqueue *vq,
struct virtblk_req *vbr)
struct virtblk_req *vbr,
struct scatterlist *data_sg,
unsigned data_nents)
{
struct scatterlist hdr, status, *sgs[3];
struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6];
unsigned int num_out = 0, num_in = 0;
int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT;
sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
sgs[num_out++] = &hdr;
if (vbr->nents) {
/*
* If this is a packet command we need a couple of additional headers.
* Behind the normal outhdr we put a segment with the scsi command
* block, and before the normal inhdr we put the sense data and the
* inhdr with additional status information.
*/
if (type == VIRTIO_BLK_T_SCSI_CMD) {
sg_init_one(&cmd, vbr->req->cmd, vbr->req->cmd_len);
sgs[num_out++] = &cmd;
}
if (data_nents) {
if (vbr->out_hdr.type & VIRTIO_BLK_T_OUT)
sgs[num_out++] = vbr->sg;
sgs[num_out++] = data_sg;
else
sgs[num_out + num_in++] = vbr->sg;
sgs[num_out + num_in++] = data_sg;
}
if (type == VIRTIO_BLK_T_SCSI_CMD) {
sg_init_one(&sense, vbr->req->sense, SCSI_SENSE_BUFFERSIZE);
sgs[num_out + num_in++] = &sense;
sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr));
sgs[num_out + num_in++] = &inhdr;
}
sg_init_one(&status, &vbr->status, sizeof(vbr->status));
@ -130,7 +151,8 @@ static void virtblk_add_req(struct virtblk_req *vbr)
int ret;
spin_lock_irq(vblk->disk->queue->queue_lock);
while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr)) < 0)) {
while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr, vbr->sg,
vbr->nents)) < 0)) {
prepare_to_wait_exclusive(&vblk->queue_wait, &wait,
TASK_UNINTERRUPTIBLE);
@ -283,7 +305,7 @@ static void virtblk_done(struct virtqueue *vq)
static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
struct request *req)
{
unsigned long num, out = 0, in = 0;
unsigned int num;
struct virtblk_req *vbr;
vbr = virtblk_alloc_req(vblk, GFP_ATOMIC);
@ -320,40 +342,15 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
}
}
sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));
/*
* If this is a packet command we need a couple of additional headers.
* Behind the normal outhdr we put a segment with the scsi command
* block, and before the normal inhdr we put the sense data and the
* inhdr with additional status information before the normal inhdr.
*/
if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC)
sg_set_buf(&vblk->sg[out++], vbr->req->cmd, vbr->req->cmd_len);
num = blk_rq_map_sg(q, vbr->req, vblk->sg + out);
if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC) {
sg_set_buf(&vblk->sg[num + out + in++], vbr->req->sense, SCSI_SENSE_BUFFERSIZE);
sg_set_buf(&vblk->sg[num + out + in++], &vbr->in_hdr,
sizeof(vbr->in_hdr));
}
sg_set_buf(&vblk->sg[num + out + in++], &vbr->status,
sizeof(vbr->status));
num = blk_rq_map_sg(q, vbr->req, vblk->sg);
if (num) {
if (rq_data_dir(vbr->req) == WRITE) {
if (rq_data_dir(vbr->req) == WRITE)
vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
out += num;
} else {
else
vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
in += num;
}
}
if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr,
GFP_ATOMIC) < 0) {
if (__virtblk_add_req(vblk->vq, vbr, vblk->sg, num) < 0) {
mempool_free(vbr, vblk->pool);
return false;
}