[SCSI] bsg: add large command support

This enables bsg to handle the request length larger than BLK_MAX_CDB
(mainly for the variable length CDB format).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/block/bsg.c b/block/bsg.c
index 23ea4fd1a66d9464b0b3af5dd53f997852f65c1a..d8b889d2e411ae7b0124897d5893d7a2b2eca7dc 100644 (file)
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -174,7 +174,11 @@ unlock:
 static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
                                struct sg_io_v4 *hdr, int has_write_perm)
 {
-       memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
+       if (hdr->request_len > BLK_MAX_CDB) {
+               rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
+               if (!rq->cmd)
+                       return -ENOMEM;
+       }
 
        if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
                           hdr->request_len))
@@ -211,8 +215,6 @@ bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
 
        if (hdr->guard != 'Q')
                return -EINVAL;
-       if (hdr->request_len > BLK_MAX_CDB)
-               return -EINVAL;
        if (hdr->dout_xfer_len > (q->max_sectors << 9) ||
            hdr->din_xfer_len > (q->max_sectors << 9))
                return -EIO;
@@ -302,6 +304,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
        }
        return rq;
 out:
+       if (rq->cmd != rq->__cmd)
+               kfree(rq->cmd);
        blk_put_request(rq);
        if (next_rq) {
                blk_rq_unmap_user(next_rq->bio);
@@ -455,6 +459,8 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
                ret = rq->errors;
 
        blk_rq_unmap_user(bio);
+       if (rq->cmd != rq->__cmd)
+               kfree(rq->cmd);
        blk_put_request(rq);
 
        return ret;