From 972248e9111ee6fe9fb56c24ecfd7434f3d713ac Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 29 Jan 2019 09:32:03 +0100 Subject: [PATCH] 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 Acked-by: Jens Axboe Signed-off-by: Martin K. Petersen --- block/bsg-lib.c | 44 +++++++++++++++++--- block/bsg.c | 68 +++++++------------------------ drivers/scsi/scsi_transport_sas.c | 1 - include/linux/bsg-lib.h | 4 ++ 4 files changed, 56 insertions(+), 61 deletions(-) diff --git a/block/bsg-lib.c b/block/bsg-lib.c index 192129856342..005e2b75d775 100644 --- a/block/bsg-lib.c +++ b/block/bsg-lib.c @@ -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); + + 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 PTR_ERR_OR_ZERO(job->request); + 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); diff --git a/block/bsg.c b/block/bsg.c index a799b0ace55c..f306853c6b08 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -74,6 +74,11 @@ static int bsg_scsi_fill_hdr(struct request *rq, struct sg_io_v4 *hdr, { struct scsi_request *sreq = scsi_req(rq); + if (hdr->dout_xfer_len && hdr->din_xfer_len) { + pr_warn_once("BIDI support in bsg has been removed.\n"); + return -EOPNOTSUPP; + } + sreq->cmd_len = hdr->request_len; if (sreq->cmd_len > BLK_MAX_CDB) { sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL); @@ -114,14 +119,10 @@ static int bsg_scsi_complete_rq(struct request *rq, struct sg_io_v4 *hdr) hdr->response_len = len; } - if (rq->next_rq) { - hdr->dout_resid = sreq->resid_len; - hdr->din_resid = scsi_req(rq->next_rq)->resid_len; - } else if (rq_data_dir(rq) == READ) { + if (rq_data_dir(rq) == READ) hdr->din_resid = sreq->resid_len; - } else { + else hdr->dout_resid = sreq->resid_len; - } return ret; } @@ -140,8 +141,8 @@ static const struct bsg_ops bsg_scsi_ops = { static int bsg_sg_io(struct request_queue *q, fmode_t mode, void __user *uarg) { - struct request *rq, *next_rq = NULL; - struct bio *bio, *bidi_bio = NULL; + struct request *rq; + struct bio *bio; struct sg_io_v4 hdr; int ret; @@ -164,7 +165,7 @@ static int bsg_sg_io(struct request_queue *q, fmode_t mode, void __user *uarg) ret = q->bsg_dev.ops->fill_hdr(rq, &hdr, mode); if (ret) - goto out; + return ret; rq->timeout = msecs_to_jiffies(hdr.timeout); if (!rq->timeout) @@ -174,29 +175,6 @@ static int bsg_sg_io(struct request_queue *q, fmode_t mode, void __user *uarg) if (rq->timeout < BLK_MIN_SG_TIMEOUT) rq->timeout = BLK_MIN_SG_TIMEOUT; - if (hdr.dout_xfer_len && hdr.din_xfer_len) { - if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) { - ret = -EOPNOTSUPP; - goto out; - } - - pr_warn_once( - "BIDI support in bsg has been deprecated and might be removed. " - "Please report your use case to linux-scsi@vger.kernel.org\n"); - - next_rq = blk_get_request(q, REQ_OP_SCSI_IN, 0); - if (IS_ERR(next_rq)) { - ret = PTR_ERR(next_rq); - goto out; - } - - rq->next_rq = next_rq; - ret = blk_rq_map_user(q, next_rq, NULL, uptr64(hdr.din_xferp), - hdr.din_xfer_len, GFP_KERNEL); - if (ret) - goto out_free_nextrq; - } - if (hdr.dout_xfer_len) { ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr.dout_xferp), hdr.dout_xfer_len, GFP_KERNEL); @@ -206,38 +184,20 @@ static int bsg_sg_io(struct request_queue *q, fmode_t mode, void __user *uarg) } if (ret) - goto out_unmap_nextrq; + goto out_free_rq; bio = rq->bio; - if (rq->next_rq) - bidi_bio = rq->next_rq->bio; blk_execute_rq(q, NULL, rq, !(hdr.flags & BSG_FLAG_Q_AT_TAIL)); ret = rq->q->bsg_dev.ops->complete_rq(rq, &hdr); - - if (rq->next_rq) { - blk_rq_unmap_user(bidi_bio); - blk_put_request(rq->next_rq); - } - blk_rq_unmap_user(bio); + +out_free_rq: rq->q->bsg_dev.ops->free_rq(rq); blk_put_request(rq); - - if (copy_to_user(uarg, &hdr, sizeof(hdr))) + if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr))) return -EFAULT; return ret; - -out_unmap_nextrq: - if (rq->next_rq) - blk_rq_unmap_user(rq->next_rq->bio); -out_free_nextrq: - if (rq->next_rq) - blk_put_request(rq->next_rq); -out: - q->bsg_dev.ops->free_rq(rq); - blk_put_request(rq); - return ret; } static struct bsg_device *bsg_alloc_device(void) diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c index 692b46937e52..60f1a81d2034 100644 --- a/drivers/scsi/scsi_transport_sas.c +++ b/drivers/scsi/scsi_transport_sas.c @@ -213,7 +213,6 @@ static int sas_bsg_initialize(struct Scsi_Host *shost, struct sas_rphy *rphy) to_sas_host_attrs(shost)->q = q; } - blk_queue_flag_set(QUEUE_FLAG_BIDI, q); return 0; } diff --git a/include/linux/bsg-lib.h b/include/linux/bsg-lib.h index b356e0006731..7f14517a559b 100644 --- a/include/linux/bsg-lib.h +++ b/include/linux/bsg-lib.h @@ -69,6 +69,10 @@ struct bsg_job { int result; unsigned int reply_payload_rcv_len; + /* BIDI support */ + struct request *bidi_rq; + struct bio *bidi_bio; + void *dd_data; /* Used for driver-specific storage */ }; -- 2.30.2