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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>
This commit is contained in:
FUJITA Tomonori 2007-07-16 08:52:15 +02:00 committed by Jens Axboe
parent abae1fde63
commit 2c9ecdf40a
1 changed files with 49 additions and 25 deletions
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74
block/bsg.c
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@ -95,6 +95,7 @@ struct bsg_command {
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 @@ bsg_validate_sgv4_hdr(request_queue_t *q, struct sg_io_v4 *hdr, int *rw)
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 @@ static struct request *
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 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
* 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 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
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 @@ static void bsg_add_command(struct bsg_device *bd, request_queue_t *q,
*/
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 struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
}
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 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
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 @@ static int bsg_complete_all_commands(struct bsg_device *bd)
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 @@ __bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
* 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 @@ bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
}
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 @@ bsg_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
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;