[PATCH] Cleanup blk_rq_map_* interfaces

Change the blk_rq_map_user() and blk_rq_map_kern() interface to require
a previously allocated request to be passed in. This is both more efficient
for multiple iterations of mapping data to the same request, and it is also
a much nicer API.

Signed-off-by: Jens Axboe <axboe@suse.de>

1 files changed, 9 insertions, 4 deletions

diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index beaa561f2ed8..6a7d926774a1 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2097,6 +2097,10 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
         if (!q)
                 return -ENXIO;
 
+        rq = blk_get_request(q, READ, GFP_KERNEL);
+        if (!rq)
+                return -ENOMEM;
+
         cdi->last_sense = 0;
 
         while (nframes) {
@@ -2108,9 +2112,9 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 
                 len = nr * CD_FRAMESIZE_RAW;
 
-                rq = blk_rq_map_user(q, READ, ubuf, len);
-                if (IS_ERR(rq))
-                        return PTR_ERR(rq);
+                ret = blk_rq_map_user(q, rq, ubuf, len);
+                if (ret)
+                        break;
 
                 memset(rq->cmd, 0, sizeof(rq->cmd));
                 rq->cmd[0] = GPCMD_READ_CD;
@@ -2138,7 +2142,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
                         cdi->last_sense = s->sense_key;
                 }
 
-                if (blk_rq_unmap_user(rq, bio, len))
+                if (blk_rq_unmap_user(bio, len))
                         ret = -EFAULT;
 
                 if (ret)
@@ -2149,6 +2153,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
                 ubuf += len;
         }
 
+        blk_put_request(rq);
         return ret;
 }