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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 <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Christoph Hellwig
Martin K. Petersen
parent
1e61c1a804
commit
75ca56409e
@ -25,32 +25,39 @@ struct bsg_set {
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bsg_timeout_fn *timeout_fn;
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};
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static int bsg_transport_check_proto(struct sg_io_v4 *hdr)
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static int bsg_transport_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
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fmode_t mode, unsigned int timeout)
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{
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struct bsg_job *job;
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struct request *rq;
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struct bio *bio;
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int ret;
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if (hdr->protocol != BSG_PROTOCOL_SCSI ||
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hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)
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return -EINVAL;
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if (!capable(CAP_SYS_RAWIO))
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return -EPERM;
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return 0;
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}
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static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,
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fmode_t mode)
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{
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struct bsg_job *job = blk_mq_rq_to_pdu(rq);
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int ret;
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rq = blk_get_request(q, hdr->dout_xfer_len ?
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REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
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if (IS_ERR(rq))
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return PTR_ERR(rq);
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rq->timeout = timeout;
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job = blk_mq_rq_to_pdu(rq);
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job->request_len = hdr->request_len;
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job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
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if (IS_ERR(job->request))
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return PTR_ERR(job->request);
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if (IS_ERR(job->request)) {
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ret = PTR_ERR(job->request);
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goto out_put_request;
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}
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if (hdr->dout_xfer_len && hdr->din_xfer_len) {
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job->bidi_rq = blk_get_request(rq->q, REQ_OP_DRV_IN, 0);
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if (IS_ERR(job->bidi_rq)) {
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ret = PTR_ERR(job->bidi_rq);
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goto out;
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goto out_free_job_request;
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}
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ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL,
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@ -65,20 +72,19 @@ static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,
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job->bidi_bio = NULL;
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}
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return 0;
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if (hdr->dout_xfer_len) {
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ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
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hdr->dout_xfer_len, GFP_KERNEL);
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} else if (hdr->din_xfer_len) {
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ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
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hdr->din_xfer_len, GFP_KERNEL);
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}
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out_free_bidi_rq:
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if (job->bidi_rq)
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blk_put_request(job->bidi_rq);
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out:
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kfree(job->request);
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return ret;
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}
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if (ret)
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goto out_unmap_bidi_rq;
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static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
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{
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struct bsg_job *job = blk_mq_rq_to_pdu(rq);
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int ret = 0;
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bio = rq->bio;
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blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
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/*
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* The assignments below don't make much sense, but are kept for
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@ -121,28 +127,20 @@ static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
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hdr->din_resid = 0;
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}
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blk_rq_unmap_user(bio);
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out_unmap_bidi_rq:
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if (job->bidi_rq)
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blk_rq_unmap_user(job->bidi_bio);
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out_free_bidi_rq:
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if (job->bidi_rq)
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blk_put_request(job->bidi_rq);
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out_free_job_request:
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kfree(job->request);
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out_put_request:
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blk_put_request(rq);
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return ret;
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}
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static void bsg_transport_free_rq(struct request *rq)
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{
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struct bsg_job *job = blk_mq_rq_to_pdu(rq);
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if (job->bidi_rq) {
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blk_rq_unmap_user(job->bidi_bio);
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blk_put_request(job->bidi_rq);
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}
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kfree(job->request);
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}
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static const struct bsg_ops bsg_transport_ops = {
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.check_proto = bsg_transport_check_proto,
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.fill_hdr = bsg_transport_fill_hdr,
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.complete_rq = bsg_transport_complete_rq,
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.free_rq = bsg_transport_free_rq,
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};
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/**
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* bsg_teardown_job - routine to teardown a bsg job
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* @kref: kref inside bsg_job that is to be torn down
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@ -398,7 +396,7 @@ struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
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q->queuedata = dev;
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blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
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bset->bd = bsg_register_queue(q, dev, name, &bsg_transport_ops);
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bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn);
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if (IS_ERR(bset->bd)) {
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ret = PTR_ERR(bset->bd);
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goto out_cleanup_queue;
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66
block/bsg.c
66
block/bsg.c
@ -22,12 +22,12 @@
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struct bsg_device {
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struct request_queue *queue;
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const struct bsg_ops *ops;
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struct device device;
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struct cdev cdev;
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int max_queue;
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unsigned int timeout;
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unsigned int reserved_size;
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bsg_sg_io_fn *sg_io_fn;
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};
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static inline struct bsg_device *to_bsg_device(struct inode *inode)
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@ -42,63 +42,28 @@ static DEFINE_IDA(bsg_minor_ida);
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static struct class *bsg_class;
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static int bsg_major;
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#define uptr64(val) ((void __user *)(uintptr_t)(val))
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static unsigned int bsg_timeout(struct bsg_device *bd, struct sg_io_v4 *hdr)
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{
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unsigned int timeout = BLK_DEFAULT_SG_TIMEOUT;
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if (hdr->timeout)
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timeout = msecs_to_jiffies(hdr->timeout);
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else if (bd->timeout)
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timeout = bd->timeout;
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return max_t(unsigned int, timeout, BLK_MIN_SG_TIMEOUT);
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}
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static int bsg_sg_io(struct bsg_device *bd, fmode_t mode, void __user *uarg)
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{
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struct request *rq;
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struct bio *bio;
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struct sg_io_v4 hdr;
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int ret;
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if (copy_from_user(&hdr, uarg, sizeof(hdr)))
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return -EFAULT;
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if (hdr.guard != 'Q')
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return -EINVAL;
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ret = bd->ops->check_proto(&hdr);
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if (ret)
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return ret;
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rq = blk_get_request(bd->queue, hdr.dout_xfer_len ?
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REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
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if (IS_ERR(rq))
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return PTR_ERR(rq);
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ret = bd->ops->fill_hdr(rq, &hdr, mode);
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if (ret) {
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blk_put_request(rq);
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return ret;
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}
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rq->timeout = msecs_to_jiffies(hdr.timeout);
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if (!rq->timeout)
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rq->timeout = bd->timeout;
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if (!rq->timeout)
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rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
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if (rq->timeout < BLK_MIN_SG_TIMEOUT)
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rq->timeout = BLK_MIN_SG_TIMEOUT;
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if (hdr.dout_xfer_len) {
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ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr.dout_xferp),
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hdr.dout_xfer_len, GFP_KERNEL);
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} else if (hdr.din_xfer_len) {
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ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr.din_xferp),
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hdr.din_xfer_len, GFP_KERNEL);
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}
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if (ret)
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goto out_free_rq;
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bio = rq->bio;
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blk_execute_rq(NULL, rq, !(hdr.flags & BSG_FLAG_Q_AT_TAIL));
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ret = bd->ops->complete_rq(rq, &hdr);
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blk_rq_unmap_user(bio);
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out_free_rq:
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bd->ops->free_rq(rq);
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blk_put_request(rq);
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ret = bd->sg_io_fn(bd->queue, &hdr, mode, bsg_timeout(bd, &hdr));
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if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr)))
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return -EFAULT;
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return ret;
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@ -211,8 +176,7 @@ void bsg_unregister_queue(struct bsg_device *bd)
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EXPORT_SYMBOL_GPL(bsg_unregister_queue);
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struct bsg_device *bsg_register_queue(struct request_queue *q,
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struct device *parent, const char *name,
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const struct bsg_ops *ops)
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struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn)
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{
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struct bsg_device *bd;
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int ret;
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@ -223,7 +187,7 @@ struct bsg_device *bsg_register_queue(struct request_queue *q,
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bd->max_queue = BSG_DEFAULT_CMDS;
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bd->reserved_size = INT_MAX;
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bd->queue = q;
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bd->ops = ops;
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bd->sg_io_fn = sg_io_fn;
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ret = ida_simple_get(&bsg_minor_ida, 0, BSG_MAX_DEVS, GFP_KERNEL);
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if (ret < 0) {
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@ -9,42 +9,57 @@
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#define uptr64(val) ((void __user *)(uintptr_t)(val))
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static int scsi_bsg_check_proto(struct sg_io_v4 *hdr)
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static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
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fmode_t mode, unsigned int timeout)
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{
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struct scsi_request *sreq;
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struct request *rq;
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struct bio *bio;
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int ret;
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if (hdr->protocol != BSG_PROTOCOL_SCSI ||
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hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD)
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return -EINVAL;
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return 0;
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}
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static int scsi_bsg_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,
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fmode_t mode)
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{
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struct scsi_request *sreq = scsi_req(rq);
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if (hdr->dout_xfer_len && hdr->din_xfer_len) {
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pr_warn_once("BIDI support in bsg has been removed.\n");
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return -EOPNOTSUPP;
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}
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rq = blk_get_request(q, hdr->dout_xfer_len ?
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REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
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if (IS_ERR(rq))
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return PTR_ERR(rq);
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rq->timeout = timeout;
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ret = -ENOMEM;
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sreq = scsi_req(rq);
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sreq->cmd_len = hdr->request_len;
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if (sreq->cmd_len > BLK_MAX_CDB) {
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sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL);
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if (!sreq->cmd)
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return -ENOMEM;
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goto out_put_request;
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}
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ret = -EFAULT;
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if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len))
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return -EFAULT;
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goto out_free_cmd;
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ret = -EPERM;
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if (!scsi_cmd_allowed(sreq->cmd, mode))
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return -EPERM;
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return 0;
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}
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goto out_free_cmd;
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static int scsi_bsg_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
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{
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struct scsi_request *sreq = scsi_req(rq);
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int ret = 0;
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if (hdr->dout_xfer_len) {
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ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
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hdr->dout_xfer_len, GFP_KERNEL);
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} else if (hdr->din_xfer_len) {
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ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
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hdr->din_xfer_len, GFP_KERNEL);
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}
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if (ret)
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goto out_free_cmd;
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bio = rq->bio;
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blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
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/*
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* fill in all the output members
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@ -74,23 +89,17 @@ static int scsi_bsg_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
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else
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hdr->dout_resid = sreq->resid_len;
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blk_rq_unmap_user(bio);
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out_free_cmd:
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scsi_req_free_cmd(scsi_req(rq));
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out_put_request:
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blk_put_request(rq);
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return ret;
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}
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static void scsi_bsg_free_rq(struct request *rq)
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{
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scsi_req_free_cmd(scsi_req(rq));
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}
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static const struct bsg_ops scsi_bsg_ops = {
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.check_proto = scsi_bsg_check_proto,
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.fill_hdr = scsi_bsg_fill_hdr,
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.complete_rq = scsi_bsg_complete_rq,
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.free_rq = scsi_bsg_free_rq,
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};
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struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev)
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{
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return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev,
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dev_name(&sdev->sdev_gendev), &scsi_bsg_ops);
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dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn);
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}
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@ -6,20 +6,14 @@
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struct bsg_device;
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struct device;
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struct request;
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struct request_queue;
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struct bsg_ops {
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int (*check_proto)(struct sg_io_v4 *hdr);
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int (*fill_hdr)(struct request *rq, struct sg_io_v4 *hdr,
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fmode_t mode);
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int (*complete_rq)(struct request *rq, struct sg_io_v4 *hdr);
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void (*free_rq)(struct request *rq);
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};
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typedef int (bsg_sg_io_fn)(struct request_queue *, struct sg_io_v4 *hdr,
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fmode_t mode, unsigned int timeout);
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struct bsg_device *bsg_register_queue(struct request_queue *q,
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struct device *parent, const char *name,
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const struct bsg_ops *ops);
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bsg_sg_io_fn *sg_io_fn);
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void bsg_unregister_queue(struct bsg_device *bcd);
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#endif /* _LINUX_BSG_H */
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