From 75ca56409e5b35aa6ceef94462f39ef4f533fc41 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 29 Jul 2021 08:48:45 +0200 Subject: [PATCH] scsi: bsg: Move the whole request execution into the SCSI/transport handlers Remove the amount of indirect calls by making the handler responsible for the entire execution of the request. Link: https://lore.kernel.org/r/20210729064845.1044147-5-hch@lst.de Signed-off-by: Christoph Hellwig Signed-off-by: Martin K. Petersen --- block/bsg-lib.c | 84 ++++++++++++++++++++--------------------- block/bsg.c | 66 ++++++++------------------------ drivers/scsi/scsi_bsg.c | 71 +++++++++++++++++++--------------- include/linux/bsg.h | 12 ++---- 4 files changed, 99 insertions(+), 134 deletions(-) diff --git a/block/bsg-lib.c b/block/bsg-lib.c index fe43f5fda6e5..239ebf747141 100644 --- a/block/bsg-lib.c +++ b/block/bsg-lib.c @@ -25,32 +25,39 @@ struct bsg_set { bsg_timeout_fn *timeout_fn; }; -static int bsg_transport_check_proto(struct sg_io_v4 *hdr) +static int bsg_transport_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr, + fmode_t mode, unsigned int timeout) { + struct bsg_job *job; + struct request *rq; + struct bio *bio; + int ret; + if (hdr->protocol != BSG_PROTOCOL_SCSI || hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT) return -EINVAL; if (!capable(CAP_SYS_RAWIO)) return -EPERM; - return 0; -} -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; + rq = blk_get_request(q, hdr->dout_xfer_len ? + REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0); + if (IS_ERR(rq)) + return PTR_ERR(rq); + rq->timeout = timeout; + job = blk_mq_rq_to_pdu(rq); 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 (IS_ERR(job->request)) { + ret = PTR_ERR(job->request); + goto out_put_request; + } if (hdr->dout_xfer_len && hdr->din_xfer_len) { job->bidi_rq = blk_get_request(rq->q, REQ_OP_DRV_IN, 0); if (IS_ERR(job->bidi_rq)) { ret = PTR_ERR(job->bidi_rq); - goto out; + goto out_free_job_request; } ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL, @@ -65,20 +72,19 @@ static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr, job->bidi_bio = NULL; } - return 0; + if (hdr->dout_xfer_len) { + ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp), + hdr->dout_xfer_len, GFP_KERNEL); + } else if (hdr->din_xfer_len) { + ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp), + hdr->din_xfer_len, GFP_KERNEL); + } -out_free_bidi_rq: - if (job->bidi_rq) - blk_put_request(job->bidi_rq); -out: - kfree(job->request); - return ret; -} + if (ret) + goto out_unmap_bidi_rq; -static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr) -{ - struct bsg_job *job = blk_mq_rq_to_pdu(rq); - int ret = 0; + bio = rq->bio; + blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL)); /* * The assignments below don't make much sense, but are kept for @@ -121,28 +127,20 @@ static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr) hdr->din_resid = 0; } + blk_rq_unmap_user(bio); +out_unmap_bidi_rq: + if (job->bidi_rq) + blk_rq_unmap_user(job->bidi_bio); +out_free_bidi_rq: + if (job->bidi_rq) + blk_put_request(job->bidi_rq); +out_free_job_request: + kfree(job->request); +out_put_request: + blk_put_request(rq); return ret; } -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); -} - -static const struct bsg_ops bsg_transport_ops = { - .check_proto = bsg_transport_check_proto, - .fill_hdr = bsg_transport_fill_hdr, - .complete_rq = bsg_transport_complete_rq, - .free_rq = bsg_transport_free_rq, -}; - /** * bsg_teardown_job - routine to teardown a bsg job * @kref: kref inside bsg_job that is to be torn down @@ -398,7 +396,7 @@ struct request_queue *bsg_setup_queue(struct device *dev, const char *name, q->queuedata = dev; blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT); - bset->bd = bsg_register_queue(q, dev, name, &bsg_transport_ops); + bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn); if (IS_ERR(bset->bd)) { ret = PTR_ERR(bset->bd); goto out_cleanup_queue; diff --git a/block/bsg.c b/block/bsg.c index 3ba74eec4ba2..351095193788 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -22,12 +22,12 @@ struct bsg_device { struct request_queue *queue; - const struct bsg_ops *ops; struct device device; struct cdev cdev; int max_queue; unsigned int timeout; unsigned int reserved_size; + bsg_sg_io_fn *sg_io_fn; }; static inline struct bsg_device *to_bsg_device(struct inode *inode) @@ -42,63 +42,28 @@ static DEFINE_IDA(bsg_minor_ida); static struct class *bsg_class; static int bsg_major; -#define uptr64(val) ((void __user *)(uintptr_t)(val)) +static unsigned int bsg_timeout(struct bsg_device *bd, struct sg_io_v4 *hdr) +{ + unsigned int timeout = BLK_DEFAULT_SG_TIMEOUT; + + if (hdr->timeout) + timeout = msecs_to_jiffies(hdr->timeout); + else if (bd->timeout) + timeout = bd->timeout; + + return max_t(unsigned int, timeout, BLK_MIN_SG_TIMEOUT); +} static int bsg_sg_io(struct bsg_device *bd, fmode_t mode, void __user *uarg) { - struct request *rq; - struct bio *bio; struct sg_io_v4 hdr; int ret; if (copy_from_user(&hdr, uarg, sizeof(hdr))) return -EFAULT; - if (hdr.guard != 'Q') return -EINVAL; - ret = bd->ops->check_proto(&hdr); - if (ret) - return ret; - - rq = blk_get_request(bd->queue, hdr.dout_xfer_len ? - REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0); - if (IS_ERR(rq)) - return PTR_ERR(rq); - - ret = bd->ops->fill_hdr(rq, &hdr, mode); - if (ret) { - blk_put_request(rq); - return ret; - } - - rq->timeout = msecs_to_jiffies(hdr.timeout); - if (!rq->timeout) - rq->timeout = bd->timeout; - if (!rq->timeout) - rq->timeout = BLK_DEFAULT_SG_TIMEOUT; - if (rq->timeout < BLK_MIN_SG_TIMEOUT) - rq->timeout = BLK_MIN_SG_TIMEOUT; - - if (hdr.dout_xfer_len) { - ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr.dout_xferp), - hdr.dout_xfer_len, GFP_KERNEL); - } else if (hdr.din_xfer_len) { - ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr.din_xferp), - hdr.din_xfer_len, GFP_KERNEL); - } - - if (ret) - goto out_free_rq; - - bio = rq->bio; - - blk_execute_rq(NULL, rq, !(hdr.flags & BSG_FLAG_Q_AT_TAIL)); - ret = bd->ops->complete_rq(rq, &hdr); - blk_rq_unmap_user(bio); - -out_free_rq: - bd->ops->free_rq(rq); - blk_put_request(rq); + ret = bd->sg_io_fn(bd->queue, &hdr, mode, bsg_timeout(bd, &hdr)); if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr))) return -EFAULT; return ret; @@ -211,8 +176,7 @@ void bsg_unregister_queue(struct bsg_device *bd) EXPORT_SYMBOL_GPL(bsg_unregister_queue); struct bsg_device *bsg_register_queue(struct request_queue *q, - struct device *parent, const char *name, - const struct bsg_ops *ops) + struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn) { struct bsg_device *bd; int ret; @@ -223,7 +187,7 @@ struct bsg_device *bsg_register_queue(struct request_queue *q, bd->max_queue = BSG_DEFAULT_CMDS; bd->reserved_size = INT_MAX; bd->queue = q; - bd->ops = ops; + bd->sg_io_fn = sg_io_fn; ret = ida_simple_get(&bsg_minor_ida, 0, BSG_MAX_DEVS, GFP_KERNEL); if (ret < 0) { diff --git a/drivers/scsi/scsi_bsg.c b/drivers/scsi/scsi_bsg.c index c0d41c45c2be..d13a67b82429 100644 --- a/drivers/scsi/scsi_bsg.c +++ b/drivers/scsi/scsi_bsg.c @@ -9,42 +9,57 @@ #define uptr64(val) ((void __user *)(uintptr_t)(val)) -static int scsi_bsg_check_proto(struct sg_io_v4 *hdr) +static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr, + fmode_t mode, unsigned int timeout) { + struct scsi_request *sreq; + struct request *rq; + struct bio *bio; + int ret; + if (hdr->protocol != BSG_PROTOCOL_SCSI || hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD) return -EINVAL; - return 0; -} - -static int scsi_bsg_fill_hdr(struct request *rq, struct sg_io_v4 *hdr, - fmode_t mode) -{ - 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; } + rq = blk_get_request(q, hdr->dout_xfer_len ? + REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0); + if (IS_ERR(rq)) + return PTR_ERR(rq); + rq->timeout = timeout; + + ret = -ENOMEM; + sreq = scsi_req(rq); sreq->cmd_len = hdr->request_len; if (sreq->cmd_len > BLK_MAX_CDB) { sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL); if (!sreq->cmd) - return -ENOMEM; + goto out_put_request; } + ret = -EFAULT; if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len)) - return -EFAULT; + goto out_free_cmd; + ret = -EPERM; if (!scsi_cmd_allowed(sreq->cmd, mode)) - return -EPERM; - return 0; -} + goto out_free_cmd; -static int scsi_bsg_complete_rq(struct request *rq, struct sg_io_v4 *hdr) -{ - struct scsi_request *sreq = scsi_req(rq); - int ret = 0; + if (hdr->dout_xfer_len) { + ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp), + hdr->dout_xfer_len, GFP_KERNEL); + } else if (hdr->din_xfer_len) { + ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp), + hdr->din_xfer_len, GFP_KERNEL); + } + + if (ret) + goto out_free_cmd; + + bio = rq->bio; + blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL)); /* * fill in all the output members @@ -74,23 +89,17 @@ static int scsi_bsg_complete_rq(struct request *rq, struct sg_io_v4 *hdr) else hdr->dout_resid = sreq->resid_len; + blk_rq_unmap_user(bio); + +out_free_cmd: + scsi_req_free_cmd(scsi_req(rq)); +out_put_request: + blk_put_request(rq); return ret; } -static void scsi_bsg_free_rq(struct request *rq) -{ - scsi_req_free_cmd(scsi_req(rq)); -} - -static const struct bsg_ops scsi_bsg_ops = { - .check_proto = scsi_bsg_check_proto, - .fill_hdr = scsi_bsg_fill_hdr, - .complete_rq = scsi_bsg_complete_rq, - .free_rq = scsi_bsg_free_rq, -}; - struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev) { return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev, - dev_name(&sdev->sdev_gendev), &scsi_bsg_ops); + dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn); } diff --git a/include/linux/bsg.h b/include/linux/bsg.h index fa21f79beda2..1ac81c809da9 100644 --- a/include/linux/bsg.h +++ b/include/linux/bsg.h @@ -6,20 +6,14 @@ struct bsg_device; struct device; -struct request; struct request_queue; -struct bsg_ops { - int (*check_proto)(struct sg_io_v4 *hdr); - int (*fill_hdr)(struct request *rq, struct sg_io_v4 *hdr, - fmode_t mode); - int (*complete_rq)(struct request *rq, struct sg_io_v4 *hdr); - void (*free_rq)(struct request *rq); -}; +typedef int (bsg_sg_io_fn)(struct request_queue *, struct sg_io_v4 *hdr, + fmode_t mode, unsigned int timeout); struct bsg_device *bsg_register_queue(struct request_queue *q, struct device *parent, const char *name, - const struct bsg_ops *ops); + bsg_sg_io_fn *sg_io_fn); void bsg_unregister_queue(struct bsg_device *bcd); #endif /* _LINUX_BSG_H */