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>

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index ba8706f6cded1f3096550762b49d3c17ae6f9064..1d78e6cf9d61e6994e3cfdb70e807e1dda1914ee 100644 (file)
--- 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;
 }