From 28018c242a4ec7017bbbf81d2d3952f820a27118 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Thu, 1 Jul 2010 19:49:17 +0900 Subject: [PATCH] block: implement an unprep function corresponding directly to prep Reviewed-by: FUJITA Tomonori Signed-off-by: Jens Axboe --- block/blk-core.c | 25 +++++++++++++++++++++++++ block/blk-settings.c | 17 +++++++++++++++++ drivers/scsi/scsi_lib.c | 2 +- include/linux/blkdev.h | 4 ++++ 4 files changed, 47 insertions(+), 1 deletion(-) diff --git a/block/blk-core.c b/block/blk-core.c index 3c3789492c10..5ab3ac22930c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -608,6 +608,7 @@ blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn, q->request_fn = rfn; q->prep_rq_fn = NULL; + q->unprep_rq_fn = NULL; q->unplug_fn = generic_unplug_device; q->queue_flags = QUEUE_FLAG_DEFAULT; q->queue_lock = lock; @@ -2133,6 +2134,26 @@ static bool blk_update_bidi_request(struct request *rq, int error, return false; } +/** + * blk_unprep_request - unprepare a request + * @req: the request + * + * This function makes a request ready for complete resubmission (or + * completion). It happens only after all error handling is complete, + * so represents the appropriate moment to deallocate any resources + * that were allocated to the request in the prep_rq_fn. The queue + * lock is held when calling this. + */ +void blk_unprep_request(struct request *req) +{ + struct request_queue *q = req->q; + + req->cmd_flags &= ~REQ_DONTPREP; + if (q->unprep_rq_fn) + q->unprep_rq_fn(q, req); +} +EXPORT_SYMBOL_GPL(blk_unprep_request); + /* * queue lock must be held */ @@ -2148,6 +2169,10 @@ static void blk_finish_request(struct request *req, int error) blk_delete_timer(req); + if (req->cmd_flags & REQ_DONTPREP) + blk_unprep_request(req); + + blk_account_io_done(req); if (req->end_io) diff --git a/block/blk-settings.c b/block/blk-settings.c index f5ed5a1187ba..a234f4bf1d6f 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -36,6 +36,23 @@ void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn) } EXPORT_SYMBOL(blk_queue_prep_rq); +/** + * blk_queue_unprep_rq - set an unprepare_request function for queue + * @q: queue + * @ufn: unprepare_request function + * + * It's possible for a queue to register an unprepare_request callback + * which is invoked before the request is finally completed. The goal + * of the function is to deallocate any data that was allocated in the + * prepare_request callback. + * + */ +void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn) +{ + q->unprep_rq_fn = ufn; +} +EXPORT_SYMBOL(blk_queue_unprep_rq); + /** * blk_queue_merge_bvec - set a merge_bvec function for queue * @q: queue diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 5f1160841b0e..ee836193f531 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -85,7 +85,7 @@ static void scsi_unprep_request(struct request *req) { struct scsi_cmnd *cmd = req->special; - req->cmd_flags &= ~REQ_DONTPREP; + blk_unprep_request(req); req->special = NULL; scsi_put_command(cmd); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 204fbe22354d..6bba04c7ec48 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -200,6 +200,7 @@ struct request_pm_state typedef void (request_fn_proc) (struct request_queue *q); typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); typedef int (prep_rq_fn) (struct request_queue *, struct request *); +typedef void (unprep_rq_fn) (struct request_queue *, struct request *); typedef void (unplug_fn) (struct request_queue *); struct bio_vec; @@ -282,6 +283,7 @@ struct request_queue request_fn_proc *request_fn; make_request_fn *make_request_fn; prep_rq_fn *prep_rq_fn; + unprep_rq_fn *unprep_rq_fn; unplug_fn *unplug_fn; merge_bvec_fn *merge_bvec_fn; prepare_flush_fn *prepare_flush_fn; @@ -841,6 +843,7 @@ extern void blk_complete_request(struct request *); extern void __blk_complete_request(struct request *); extern void blk_abort_request(struct request *); extern void blk_abort_queue(struct request_queue *); +extern void blk_unprep_request(struct request *); /* * Access functions for manipulating queue properties @@ -885,6 +888,7 @@ extern int blk_queue_dma_drain(struct request_queue *q, extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); +extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); extern void blk_queue_dma_alignment(struct request_queue *, int); extern void blk_queue_update_dma_alignment(struct request_queue *, int);