From: Kiyoshi Ueda Date: Tue, 11 Dec 2007 22:51:46 +0000 (-0500) Subject: blk_end_request: add bidi completion interface (take 4) X-Git-Tag: v2.6.25-rc1~1172^2~6 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e3a04fe34a3ec81ddeddb6c73fb7299716cffbb0;p=linux-2.6 blk_end_request: add bidi completion interface (take 4) This patch adds a variant of the interface, blk_end_bidi_request(), which completes a bidi request. Bidi request must be completed as a whole, both rq and rq->next_rq at once. So the interface has 2 arguments for completion size. As for ->end_io, only rq->end_io is called (rq->next_rq->end_io is not called). So if special completion handling is needed, the handler must be set to rq->end_io. And the handler must take care of freeing next_rq too, since the interface doesn't care of it if rq->end_io is not NULL. Cc: Boaz Harrosh Signed-off-by: Kiyoshi Ueda Signed-off-by: Jun'ichi Nomura Signed-off-by: Jens Axboe --- diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 919e4baf47..4889f7a8c2 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -3821,6 +3821,9 @@ static void complete_request(struct request *rq, int error) if (blk_queued_rq(rq)) blkdev_dequeue_request(rq); + if (blk_bidi_rq(rq) && !rq->end_io) + __blk_put_request(rq->next_rq->q, rq->next_rq); + end_that_request_last(rq, uptodate); } @@ -3828,14 +3831,15 @@ static void complete_request(struct request *rq, int error) * blk_end_io - Generic end_io function to complete a request. * @rq: the request being processed * @error: 0 for success, < 0 for error - * @nr_bytes: number of bytes to complete + * @nr_bytes: number of bytes to complete @rq + * @bidi_bytes: number of bytes to complete @rq->next_rq * @drv_callback: function called between completion of bios in the request * and completion of the request. * If the callback returns non 0, this helper returns without * completion of the request. * * Description: - * Ends I/O on a number of bytes attached to @rq. + * Ends I/O on a number of bytes attached to @rq and @rq->next_rq. * If @rq has leftover, sets it up for the next range of segments. * * Return: @@ -3843,7 +3847,7 @@ static void complete_request(struct request *rq, int error) * 1 - this request is not freed yet, it still has pending buffers. **/ static int blk_end_io(struct request *rq, int error, int nr_bytes, - int (drv_callback)(struct request *)) + int bidi_bytes, int (drv_callback)(struct request *)) { struct request_queue *q = rq->q; unsigned long flags = 0UL; @@ -3858,6 +3862,11 @@ static int blk_end_io(struct request *rq, int error, int nr_bytes, if (blk_fs_request(rq) || blk_pc_request(rq)) { if (__end_that_request_first(rq, uptodate, nr_bytes)) return 1; + + /* Bidi request must be completed as a whole */ + if (blk_bidi_rq(rq) && + __end_that_request_first(rq->next_rq, uptodate, bidi_bytes)) + return 1; } /* Special feature for tricky drivers */ @@ -3889,7 +3898,7 @@ static int blk_end_io(struct request *rq, int error, int nr_bytes, **/ int blk_end_request(struct request *rq, int error, int nr_bytes) { - return blk_end_io(rq, error, nr_bytes, NULL); + return blk_end_io(rq, error, nr_bytes, 0, NULL); } EXPORT_SYMBOL_GPL(blk_end_request); @@ -3929,6 +3938,27 @@ int __blk_end_request(struct request *rq, int error, 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, int nr_bytes, + int bidi_bytes) +{ + return blk_end_io(rq, error, nr_bytes, bidi_bytes, NULL); +} +EXPORT_SYMBOL_GPL(blk_end_bidi_request); + /** * blk_end_request_callback - Special helper function for tricky drivers * @rq: the request being processed @@ -3957,7 +3987,7 @@ EXPORT_SYMBOL_GPL(__blk_end_request); int blk_end_request_callback(struct request *rq, int error, int nr_bytes, int (drv_callback)(struct request *)) { - return blk_end_io(rq, error, nr_bytes, drv_callback); + return blk_end_io(rq, error, nr_bytes, 0, drv_callback); } EXPORT_SYMBOL_GPL(blk_end_request_callback); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 63fe7542b3..029b7097f9 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -728,6 +728,8 @@ static inline void blk_run_address_space(struct address_space *mapping) */ extern int blk_end_request(struct request *rq, int error, int nr_bytes); extern int __blk_end_request(struct request *rq, int error, int nr_bytes); +extern int blk_end_bidi_request(struct request *rq, int error, int nr_bytes, + int bidi_bytes); extern int end_that_request_first(struct request *, int, int); extern int end_that_request_chunk(struct request *, int, int); extern void end_that_request_last(struct request *, int);