scsi: bsg-lib: handle bidi requests without block layer help

We can just stash away the second request in struct bsg_job instead of
using the block layer req->next_rq field, allowing for the eventual removal
of the latter.

Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Jens Axboe <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
This commit is contained in:
Christoph Hellwig 2019-01-29 09:32:03 +01:00 • committed by Martin K. Petersen
commit 972248e911
4 changed files with 56 additions and 61 deletions

View file

@ -51,11 +51,40 @@ static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,
fmode_t mode)
{
struct bsg_job *job = blk_mq_rq_to_pdu(rq);
int ret;
job->request_len = hdr->request_len;
job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
if (IS_ERR(job->request))
return PTR_ERR(job->request);
return PTR_ERR_OR_ZERO(job->request);
if (hdr->dout_xfer_len && hdr->din_xfer_len) {
job->bidi_rq = blk_get_request(rq->q, REQ_OP_SCSI_IN, 0);
if (IS_ERR(job->bidi_rq)) {
ret = PTR_ERR(job->bidi_rq);
goto out;
}
ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL,
uptr64(hdr->din_xferp), hdr->din_xfer_len,
GFP_KERNEL);
if (ret)
goto out_free_bidi_rq;
job->bidi_bio = job->bidi_rq->bio;
} else {
job->bidi_rq = NULL;
job->bidi_bio = NULL;
}
return 0;
out_free_bidi_rq:
if (job->bidi_rq)
blk_put_request(job->bidi_rq);
out:
kfree(job->request);
return ret;
}
static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
@ -93,7 +122,7 @@ static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
/* we assume all request payload was transferred, residual == 0 */
hdr->dout_resid = 0;
if (rq->next_rq) {
if (job->bidi_rq) {
unsigned int rsp_len = job->reply_payload.payload_len;
if (WARN_ON(job->reply_payload_rcv_len > rsp_len))
@ -111,6 +140,11 @@ static void bsg_transport_free_rq(struct request *rq)
{
struct bsg_job *job = blk_mq_rq_to_pdu(rq);
if (job->bidi_rq) {
blk_rq_unmap_user(job->bidi_bio);
blk_put_request(job->bidi_rq);
}
kfree(job->request);
}
@ -200,7 +234,6 @@ static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
*/
static bool bsg_prepare_job(struct device *dev, struct request *req)
{
struct request *rsp = req->next_rq;
struct bsg_job *job = blk_mq_rq_to_pdu(req);
int ret;
@ -211,8 +244,8 @@ static bool bsg_prepare_job(struct device *dev, struct request *req)
if (ret)
goto failjob_rls_job;
}
if (rsp && rsp->bio) {
ret = bsg_map_buffer(&job->reply_payload, rsp);
if (job->bidi_rq) {
ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq);
if (ret)
goto failjob_rls_rqst_payload;
}
@ -369,7 +402,6 @@ struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
}
q->queuedata = dev;
blk_queue_flag_set(QUEUE_FLAG_BIDI, q);
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
ret = bsg_register_queue(q, dev, name, &bsg_transport_ops);