scsi: bsg: refactor bsg_ioctl

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Tested-by: Benjamin Block <bblock@linux.ibm.com>
Tested-by: Avri Altman <avri.altman@wdc.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/block/bsg.c b/block/bsg.c
index 50e5f8f..a799b0a 100644 (file)
--- 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;
@@ -188,42 +191,29 @@ 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);
@@ -233,6 +223,20 @@ 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;
 }
 
@@ -367,31 +371,39 @@ 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
@@ -404,36 +416,10 @@ 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;
        }