Besides the OSD command set that never got traction, the only SCSI command using bidirectional buffers is XDWRITEREAD in the 10 and 32 byte variants, which is extremely esoteric and has been removed from the spec again as of SBC4r15. It probably doesn't make sense to keep the support code around just for that, so start deprecating the support. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- Changes since v1: - mention that XDWRITEREAD has been removed from SBC block/bsg.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/bsg.c b/block/bsg.c index 44f6028b9567..50e5f8f666f2 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -177,6 +177,10 @@ bsg_map_hdr(struct request_queue *q, struct sg_io_v4 *hdr, fmode_t mode) goto out; } + pr_warn_once( + "BIDI support in bsg has been deprecated and might be removed. " + "Please report your use case to linux-scsi@xxxxxxxxxxxxxxx\n"); + next_rq = blk_get_request(q, REQ_OP_SCSI_IN, 0); if (IS_ERR(next_rq)) { ret = PTR_ERR(next_rq); -- 2.19.2