block: support > 16 byte CDBs for SG_IO

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 17 insertions, 7 deletions

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index ba8706f6cded..1d78e6cf9d61 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -296,8 +296,6 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 
         if (hdr->interface_id != 'S')
                 return -EINVAL;
-        if (hdr->cmd_len > BLK_MAX_CDB)
-                return -EINVAL;
 
         if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
                 return -EIO;
@@ -316,14 +314,21 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
         if (hdr->flags & SG_FLAG_Q_AT_HEAD)
                 at_head = 1;
 
+        ret = -ENOMEM;
         rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
         if (!rq)
-                return -ENOMEM;
+                goto out;
         blk_rq_set_block_pc(rq);
 
+        if (hdr->cmd_len > BLK_MAX_CDB) {
+                rq->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
+                if (!rq->cmd)
+                        goto out_put_request;
+        }
+
         ret = -EFAULT;
         if (blk_fill_sghdr_rq(q, rq, hdr, mode))
-                goto out;
+                goto out_free_cdb;
 
         if (hdr->iovec_count) {
                 size_t iov_data_len;
@@ -333,7 +338,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
                                             0, NULL, &iov);
                 if (ret < 0) {
                         kfree(iov);
-                        goto out;
+                        goto out_free_cdb;
                 }
 
                 iov_data_len = ret;
@@ -356,7 +361,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
                                       GFP_KERNEL);
 
         if (ret)
-                goto out;
+                goto out_free_cdb;
 
         bio = rq->bio;
         memset(sense, 0, sizeof(sense));
@@ -375,8 +380,13 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
         hdr->duration = jiffies_to_msecs(jiffies - start_time);
 
         ret = blk_complete_sghdr_rq(rq, hdr, bio);
-out:
+
+out_free_cdb:
+        if (rq->cmd != rq->__cmd)
+                kfree(rq->cmd);
+out_put_request:
         blk_put_request(rq);
+out:
         return ret;
 }