diff options
| -rw-r--r-- | include/linux/blkdev_compat.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/blkdev_compat.h b/include/linux/blkdev_compat.h index d2e80ec88..3bf1f4574 100644 --- a/include/linux/blkdev_compat.h +++ b/include/linux/blkdev_compat.h @@ -172,6 +172,17 @@ __blk_rq_bytes(struct request *req) #define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS) #endif +/* + * 2.6.27 API change, + * The blk_queue_stackable() queue flag was added in 2.6.27 to handle dm + * stacking drivers. Prior to this request stacking drivers were detected + * by checking (q->request_fn == NULL), for earlier kernels we revert to + * this legacy behavior. + */ +#ifndef blk_queue_stackable +#define blk_queue_stackable(q) ((q)->request_fn == NULL) +#endif + #ifndef HAVE_GET_DISK_RO static inline int get_disk_ro(struct gendisk *disk) |