Add a unprep_rq_fn to the block layer allowing a function to be called if
set to release resources if a request is being unprepared at the block
level.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Cc: Jens Axobe <jens.axboe@oracle.com>
---
block/blk-settings.c | 17 +++++++++++++++++
include/linux/blkdev.h | 3 +++
2 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index d9a9db5..1a33494 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 a unprepare_request function for queue
+ * @q: queue
+ * @pfn: unprepare_request function
+ *
+ * It's possible for a queue to register a unprepare_request callback which
+ * may be invoked to unprepare a request that is on a queue. The goal of
+ * the function is to unprepare a request for I/O, it can be used to
+ * release a cdb from the request for instance.
+ *
+ */
+void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *unpfn)
+{
+ q->unprep_rq_fn = unpfn;
+}
+EXPORT_SYMBOL(blk_queue_unprep_rq);
+
+/**
* blk_queue_merge_bvec - set a merge_bvec function for queue
* @q: queue
* @mbfn: merge_bvec_fn
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ebd22db..2818e80 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -259,6 +259,7 @@ 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;
@@ -341,6 +342,7 @@ 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;
@@ -968,6 +970,7 @@ 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 *unpfn);
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);
--
1.6.6.1
--
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blk: Add a unprep_rq_fn
