Commit f7566457 authored by Jens Axboe's avatar Jens Axboe

block: add callback function for unplug notification

MD would like to know when a queue is unplugged, so it can flush
it's bitmap writes. Add such a callback.
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 18811272
...@@ -2672,6 +2672,9 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth) ...@@ -2672,6 +2672,9 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth)
{ {
trace_block_unplug_io(q, depth); trace_block_unplug_io(q, depth);
__blk_run_queue(q, false); __blk_run_queue(q, false);
if (q->unplugged_fn)
q->unplugged_fn(q);
} }
static void flush_plug_list(struct blk_plug *plug) static void flush_plug_list(struct blk_plug *plug)
......
...@@ -790,6 +790,22 @@ void blk_queue_flush(struct request_queue *q, unsigned int flush) ...@@ -790,6 +790,22 @@ void blk_queue_flush(struct request_queue *q, unsigned int flush)
} }
EXPORT_SYMBOL_GPL(blk_queue_flush); EXPORT_SYMBOL_GPL(blk_queue_flush);
/**
* blk_queue_unplugged - register a callback for an unplug event
* @q: the request queue for the device
* @fn: the function to call
*
* Some stacked drivers may need to know when IO is dispatched on an
* unplug event. By registrering a callback here, they will be notified
* when someone flushes their on-stack queue plug. The function will be
* called with the queue lock held.
*/
void blk_queue_unplugged(struct request_queue *q, unplugged_fn *fn)
{
q->unplugged_fn = fn;
}
EXPORT_SYMBOL(blk_queue_unplugged);
static int __init blk_settings_init(void) static int __init blk_settings_init(void)
{ {
blk_max_low_pfn = max_low_pfn - 1; blk_max_low_pfn = max_low_pfn - 1;
......
...@@ -196,6 +196,7 @@ typedef void (request_fn_proc) (struct request_queue *q); ...@@ -196,6 +196,7 @@ typedef void (request_fn_proc) (struct request_queue *q);
typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
typedef int (prep_rq_fn) (struct request_queue *, struct request *); typedef int (prep_rq_fn) (struct request_queue *, struct request *);
typedef void (unprep_rq_fn) (struct request_queue *, struct request *); typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
typedef void (unplugged_fn) (struct request_queue *);
struct bio_vec; struct bio_vec;
struct bvec_merge_data { struct bvec_merge_data {
...@@ -283,6 +284,7 @@ struct request_queue ...@@ -283,6 +284,7 @@ struct request_queue
rq_timed_out_fn *rq_timed_out_fn; rq_timed_out_fn *rq_timed_out_fn;
dma_drain_needed_fn *dma_drain_needed; dma_drain_needed_fn *dma_drain_needed;
lld_busy_fn *lld_busy_fn; lld_busy_fn *lld_busy_fn;
unplugged_fn *unplugged_fn;
/* /*
* Dispatch queue sorting * Dispatch queue sorting
...@@ -841,6 +843,7 @@ extern void blk_queue_dma_alignment(struct request_queue *, int); ...@@ -841,6 +843,7 @@ extern void blk_queue_dma_alignment(struct request_queue *, int);
extern void blk_queue_update_dma_alignment(struct request_queue *, int); extern void blk_queue_update_dma_alignment(struct request_queue *, int);
extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_unplugged(struct request_queue *, unplugged_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush); extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
......
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