bsg: add bidi support
bsg uses the rq->next_rq pointer for a bidi request.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/bsg.c b/block/bsg.c
index 5f4abc9..13ecc95 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -95,6 +95,7 @@
struct list_head list;
struct request *rq;
struct bio *bio;
+ struct bio *bidi_bio;
int err;
struct sg_io_v4 hdr;
struct sg_io_v4 __user *uhdr;
@@ -243,16 +244,6 @@
if (hdr->protocol || hdr->subprotocol)
return -EINVAL;
- /*
- * looks sane, if no data then it should be fine from our POV
- */
- if (!hdr->dout_xfer_len && !hdr->din_xfer_len)
- return 0;
-
- /* not supported currently */
- if (hdr->dout_xfer_len && hdr->din_xfer_len)
- return -EINVAL;
-
*rw = hdr->dout_xfer_len ? WRITE : READ;
return 0;
@@ -265,7 +256,7 @@
bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
{
request_queue_t *q = bd->queue;
- struct request *rq;
+ struct request *rq, *next_rq = NULL;
int ret, rw = 0; /* shut up gcc */
unsigned int dxfer_len;
void *dxferp = NULL;
@@ -282,11 +273,30 @@
* map scatter-gather elements seperately and string them to request
*/
rq = blk_get_request(q, rw, GFP_KERNEL);
+ if (!rq)
+ return ERR_PTR(-ENOMEM);
ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM,
&bd->flags));
- if (ret) {
- blk_put_request(rq);
- return ERR_PTR(ret);
+ if (ret)
+ goto out;
+
+ if (rw == WRITE && hdr->din_xfer_len) {
+ if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ next_rq = blk_get_request(q, READ, GFP_KERNEL);
+ if (!next_rq) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ rq->next_rq = next_rq;
+
+ dxferp = (void*)(unsigned long)hdr->din_xferp;
+ ret = blk_rq_map_user(q, next_rq, dxferp, hdr->din_xfer_len);
+ if (ret)
+ goto out;
}
if (hdr->dout_xfer_len) {
@@ -300,14 +310,17 @@
if (dxfer_len) {
ret = blk_rq_map_user(q, rq, dxferp, dxfer_len);
- if (ret) {
- dprintk("failed map at %d\n", ret);
- blk_put_request(rq);
- rq = ERR_PTR(ret);
- }
+ if (ret)
+ goto out;
}
-
return rq;
+out:
+ blk_put_request(rq);
+ if (next_rq) {
+ blk_rq_unmap_user(next_rq->bio);
+ blk_put_request(next_rq);
+ }
+ return ERR_PTR(ret);
}
/*
@@ -346,6 +359,8 @@
*/
bc->rq = rq;
bc->bio = rq->bio;
+ if (rq->next_rq)
+ bc->bidi_bio = rq->next_rq->bio;
bc->hdr.duration = jiffies;
spin_lock_irq(&bd->lock);
list_add_tail(&bc->list, &bd->busy_list);
@@ -402,7 +417,7 @@
}
static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
- struct bio *bio)
+ struct bio *bio, struct bio *bidi_bio)
{
int ret = 0;
@@ -431,6 +446,11 @@
ret = -EFAULT;
}
+ if (rq->next_rq) {
+ blk_rq_unmap_user(bidi_bio);
+ blk_put_request(rq->next_rq);
+ }
+
blk_rq_unmap_user(bio);
blk_put_request(rq);
@@ -477,7 +497,8 @@
if (IS_ERR(bc))
break;
- tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio);
+ tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
+ bc->bidi_bio);
if (!ret)
ret = tret;
@@ -511,7 +532,8 @@
* after completing the request. so do that here,
* bsg_complete_work() cannot do that for us
*/
- ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio);
+ ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
+ bc->bidi_bio);
if (copy_to_user(buf, (char *) &bc->hdr, sizeof(bc->hdr)))
ret = -EFAULT;
@@ -868,7 +890,7 @@
}
case SG_IO: {
struct request *rq;
- struct bio *bio;
+ struct bio *bio, *bidi_bio = NULL;
struct sg_io_v4 hdr;
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
@@ -879,8 +901,10 @@
return PTR_ERR(rq);
bio = rq->bio;
+ if (rq->next_rq)
+ bidi_bio = rq->next_rq->bio;
blk_execute_rq(bd->queue, NULL, rq, 0);
- blk_complete_sgv4_hdr_rq(rq, &hdr, bio);
+ blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
if (copy_to_user(uarg, &hdr, sizeof(hdr)))
return -EFAULT;