Hi Jens, FC people have been working on FC pass thru feature using bsg bidi support. Seems that the bidi API confuse them: http://marc.info/?l=linux-scsi&m=122704347209856&w=2 = From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> [PATCH] block: integrate blk_end_bidi_request with blk_end_request This integrates blk_end_bidi_request into blk_end_request. IOW, it changes blk_end_request to handle both bidi and non-bidi requests and removes blk_end_bidi_request. Currently, we have two functions to complete a request, blk_end_bidi_request and blk_end_request. The former is for bidi requests and the latter is for non-bidi. This seems to confuse developers. Questions like "can blk_end_bidi_request be used with non-bidi requests?", "what should be passed as the bidi_bytes argument in blk_end_bidi_request" are often asked. The callers don't care about whether a request is bidi or not. All they want to do is to complete a request. I think that a single function that can complete any request would be easy to understand. We always must complete all bytes on both sides with bidi. So blk_end_request easily can do it for the callers and handle both both bidi and non-bidi requests. Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> --- block/blk-core.c | 35 +++++++++++++---------------------- drivers/scsi/scsi_lib.c | 3 +-- include/linux/blkdev.h | 2 -- 3 files changed, 14 insertions(+), 26 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 10e8a64..634f918 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1943,7 +1943,19 @@ static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes, **/ int blk_end_request(struct request *rq, int error, unsigned int nr_bytes) { - return blk_end_io(rq, error, nr_bytes, 0, NULL); + unsigned int bidi_bytes = 0; + + if (blk_bidi_rq(rq)) { + struct bio *bio; + /* + * We can't use rq->next_rq->data_len here because the + * callers might set it to a residual length. + */ + __rq_for_each_bio(bio, rq->next_rq) + bidi_bytes += bio->bi_size; + } + + return blk_end_io(rq, error, nr_bytes, bidi_bytes, NULL); } EXPORT_SYMBOL_GPL(blk_end_request); @@ -1974,27 +1986,6 @@ int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes) EXPORT_SYMBOL_GPL(__blk_end_request); /** - * blk_end_bidi_request - Helper function for drivers to complete bidi request. - * @rq: the bidi request being processed - * @error: %0 for success, < %0 for error - * @nr_bytes: number of bytes to complete @rq - * @bidi_bytes: number of bytes to complete @rq->next_rq - * - * Description: - * Ends I/O on a number of bytes attached to @rq and @rq->next_rq. - * - * Return: - * %0 - we are done with this request - * %1 - still buffers pending for this request - **/ -int blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes, - unsigned int bidi_bytes) -{ - return blk_end_io(rq, error, nr_bytes, bidi_bytes, NULL); -} -EXPORT_SYMBOL_GPL(blk_end_bidi_request); - -/** * blk_update_request - Special helper function for request stacking drivers * @rq: the request being processed * @error: %0 for success, < %0 for error diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index f5d3b96..e550e3b 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -842,13 +842,12 @@ static void scsi_end_bidi_request(struct scsi_cmnd *cmd) { struct request *req = cmd->request; unsigned int dlen = req->data_len; - unsigned int next_dlen = req->next_rq->data_len; req->data_len = scsi_out(cmd)->resid; req->next_rq->data_len = scsi_in(cmd)->resid; /* The req and req->next_rq have not been completed */ - BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen)); + BUG_ON(blk_end_request(req, 0, dlen)); scsi_release_buffers(cmd); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a135256..2a22755 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -799,8 +799,6 @@ extern int blk_end_request(struct request *rq, int error, unsigned int nr_bytes); extern int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes); -extern int blk_end_bidi_request(struct request *rq, int error, - unsigned int nr_bytes, unsigned int bidi_bytes); extern void end_request(struct request *, int); extern int blk_end_request_callback(struct request *rq, int error, unsigned int nr_bytes, -- 1.5.5.GIT -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
