[PATCH] block: support larger block pc requests

This patch modifies blk_rq_map/unmap_user() and the cdrom and scsi_ioctl.c
users so that it supports requests larger than bio by chaining them together.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 26 insertions, 27 deletions

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index e55a75621437..5493c2fbbab1 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -226,7 +226,6 @@ static int sg_io(struct file *file, request_queue_t *q,
         unsigned long start_time;
         int writing = 0, ret = 0;
         struct request *rq;
-        struct bio *bio;
         char sense[SCSI_SENSE_BUFFERSIZE];
         unsigned char cmd[BLK_MAX_CDB];
 
@@ -258,30 +257,6 @@ static int sg_io(struct file *file, request_queue_t *q,
         if (!rq)
                 return -ENOMEM;
 
-        if (hdr->iovec_count) {
-                const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
-                struct sg_iovec *iov;
-
-                iov = kmalloc(size, GFP_KERNEL);
-                if (!iov) {
-                        ret = -ENOMEM;
-                        goto out;
-                }
-
-                if (copy_from_user(iov, hdr->dxferp, size)) {
-                        kfree(iov);
-                        ret = -EFAULT;
-                        goto out;
-                }
-
-                ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count);
-                kfree(iov);
-        } else if (hdr->dxfer_len)
-                ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
-
-        if (ret)
-                goto out;
-
         /*
          * fill in request structure
          */
@@ -294,7 +269,6 @@ static int sg_io(struct file *file, request_queue_t *q,
         rq->sense_len = 0;
 
         rq->cmd_type = REQ_TYPE_BLOCK_PC;
-        bio = rq->bio;
 
         /*
          * bounce this after holding a reference to the original bio, it's
@@ -309,6 +283,31 @@ static int sg_io(struct file *file, request_queue_t *q,
         if (!rq->timeout)
                 rq->timeout = BLK_DEFAULT_TIMEOUT;
 
+        if (hdr->iovec_count) {
+                const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
+                struct sg_iovec *iov;
+
+                iov = kmalloc(size, GFP_KERNEL);
+                if (!iov) {
+                        ret = -ENOMEM;
+                        goto out;
+                }
+
+                if (copy_from_user(iov, hdr->dxferp, size)) {
+                        kfree(iov);
+                        ret = -EFAULT;
+                        goto out;
+                }
+
+                ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count,
+                                          hdr->dxfer_len);
+                kfree(iov);
+        } else if (hdr->dxfer_len)
+                ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
+
+        if (ret)
+                goto out;
+
         rq->retries = 0;
 
         start_time = jiffies;
@@ -339,7 +338,7 @@ static int sg_io(struct file *file, request_queue_t *q,
                         hdr->sb_len_wr = len;
         }
 
-        if (blk_rq_unmap_user(bio, hdr->dxfer_len))
+        if (blk_rq_unmap_user(rq))
                 ret = -EFAULT;
 
         /* may not have succeeded, but output values written to control