[PATCH 5/8] bsg: refactor bsg_ioctl

Christoph Hellwig
2018-11-11T13:32:37Z

Move all actual functionality into helpers, just leaving the dispatch
in this function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/bsg.c | 158 ++++++++++++++++++++++++----------------------------
1 file changed, 72 insertions(+), 86 deletions(-)

diff --git a/block/bsg.c b/block/bsg.c
index 9a442c23a715..8bf3af9543d0 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -138,32 +138,35 @@ static const struct bsg_ops bsg_scsi_ops = {
.free_rq = bsg_scsi_free_rq,
};

-static struct request *
-bsg_map_hdr(struct request_queue *q, struct sg_io_v4 *hdr, fmode_t mode)
+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 sg_io_v4 hdr;
int ret;

- if (!q->bsg_dev.class_dev)
- return ERR_PTR(-ENXIO);
+ if (copy_from_user(&hdr, uarg, sizeof(hdr)))
+ return -EFAULT;

- if (hdr->guard != 'Q')
- return ERR_PTR(-EINVAL);
+ if (!q->bsg_dev.class_dev)
+ return -ENXIO;

- ret = q->bsg_dev.ops->check_proto(hdr);
+ if (hdr.guard != 'Q')
+ return -EINVAL;
+ ret = q->bsg_dev.ops->check_proto(&hdr);
if (ret)
- return ERR_PTR(ret);
+ return ret;

- rq = blk_get_request(q, hdr->dout_xfer_len ?
+ rq = blk_get_request(q, hdr.dout_xfer_len ?
REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
if (IS_ERR(rq))
- return rq;
+ return PTR_ERR(rq);

- ret = q->bsg_dev.ops->fill_hdr(rq, hdr, mode);
+ ret = q->bsg_dev.ops->fill_hdr(rq, &hdr, mode);
if (ret)
goto out;

- rq->timeout = msecs_to_jiffies(hdr->timeout);
+ rq->timeout = msecs_to_jiffies(hdr.timeout);
if (!rq->timeout)
rq->timeout = q->sg_timeout;
if (!rq->timeout)
@@ -171,7 +174,7 @@ bsg_map_hdr(struct request_queue *q, struct sg_io_v4 *hdr, fmode_t mode)
if (rq->timeout < BLK_MIN_SG_TIMEOUT)
rq->timeout = BLK_MIN_SG_TIMEOUT;

- if (hdr->dout_xfer_len && hdr->din_xfer_len) {
+ if (hdr.dout_xfer_len && hdr.din_xfer_len) {
if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
ret = -EOPNOTSUPP;
goto out;
@@ -184,42 +187,29 @@ bsg_map_hdr(struct request_queue *q, struct sg_io_v4 *hdr, fmode_t mode)
}

rq->next_rq = next_rq;
- ret = blk_rq_map_user(q, next_rq, NULL, uptr64(hdr->din_xferp),
- hdr->din_xfer_len, GFP_KERNEL);
+ 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);
- } else if (hdr->din_xfer_len) {
- ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr->din_xferp),
- hdr->din_xfer_len, GFP_KERNEL);
+ if (hdr.dout_xfer_len) {
+ ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr.dout_xferp),
+ hdr.dout_xfer_len, GFP_KERNEL);
+ } else if (hdr.din_xfer_len) {
+ ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr.din_xferp),
+ hdr.din_xfer_len, GFP_KERNEL);
}

if (ret)
goto out_unmap_nextrq;
- return rq;

-out_unmap_nextrq:
+ bio = rq->bio;
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 ERR_PTR(ret);
-}
-
-static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
- struct bio *bio, struct bio *bidi_bio)
-{
- int ret;
+ bidi_bio = rq->next_rq->bio;

- ret = rq->q->bsg_dev.ops->complete_rq(rq, hdr);
+ 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);
@@ -229,6 +219,20 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
blk_rq_unmap_user(bio);
rq->q->bsg_dev.ops->free_rq(rq);
blk_put_request(rq);
+
+ if (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;
}

@@ -363,31 +367,39 @@ static int bsg_release(struct inode *inode, struct file *file)
return bsg_put_device(bd);
}

+static int bsg_get_command_q(struct bsg_device *bd, int __user *uarg)
+{
+ return put_user(bd->max_queue, uarg);
+}
+
+static int bsg_set_command_q(struct bsg_device *bd, int __user *uarg)
+{
+ int queue;
+
+ if (get_user(queue, uarg))
+ return -EFAULT;
+ if (queue < 1)
+ return -EINVAL;
+
+ spin_lock_irq(&bd->lock);
+ bd->max_queue = queue;
+ spin_unlock_irq(&bd->lock);
+ return 0;
+}
+
static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct bsg_device *bd = file->private_data;
- int __user *uarg = (int __user *) arg;
- int ret;
+ void __user *uarg = (void __user *) arg;

switch (cmd) {
- /*
- * our own ioctls
- */
+ /*
+ * Our own ioctls
+ */
case SG_GET_COMMAND_Q:
- return put_user(bd->max_queue, uarg);
- case SG_SET_COMMAND_Q: {
- int queue;
-
- if (get_user(queue, uarg))
- return -EFAULT;
- if (queue < 1)
- return -EINVAL;
-
- spin_lock_irq(&bd->lock);
- bd->max_queue = queue;
- spin_unlock_irq(&bd->lock);
- return 0;
- }
+ return bsg_get_command_q(bd, uarg);
+ case SG_SET_COMMAND_Q:
+ return bsg_set_command_q(bd, uarg);

/*
* SCSI/sg ioctls
@@ -400,36 +412,10 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case SG_GET_RESERVED_SIZE:
case SG_SET_RESERVED_SIZE:
case SG_EMULATED_HOST:
- case SCSI_IOCTL_SEND_COMMAND: {
- void __user *uarg = (void __user *) arg;
+ case SCSI_IOCTL_SEND_COMMAND:
return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
- }
- case SG_IO: {
- struct request *rq;
- struct bio *bio, *bidi_bio = NULL;
- struct sg_io_v4 hdr;
- int at_head;
-
- if (copy_from_user(&hdr, uarg, sizeof(hdr)))
- return -EFAULT;
-
- rq = bsg_map_hdr(bd->queue, &hdr, file->f_mode);
- if (IS_ERR(rq))
- return PTR_ERR(rq);
-
- bio = rq->bio;
- if (rq->next_rq)
- bidi_bio = rq->next_rq->bio;
-
- at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
- blk_execute_rq(bd->queue, NULL, rq, at_head);
- ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
-
- if (copy_to_user(uarg, &hdr, sizeof(hdr)))
- return -EFAULT;
-
- return ret;
- }
+ case SG_IO:
+ return bsg_sg_io(bd->queue, file->f_mode, uarg);
default:
return -ENOTTY;
}
--
2.19.1