From: Jens Axboe <axboe@suse.de>
This is needed for several things, one in-tree user which I will introduce
after this patch.
This adds a ->end_io callback to struct request, so it can be used with
async io of any sort. Right now users have to wait for completion in a
blocking manner. In the next iteration, ->waiting can be folded into
->end_io_data since it is just a special case of that use.
From: Peter Osterlund <petero2@telia.com>
The problem is that the add-struct-request-end_io-callback patch forgot to
update pktcdvd.c. This patch fixes it.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/drivers/block/ll_rw_blk.c | 36 ++++++++++++++++++++++++++++--------
25-akpm/drivers/block/paride/pd.c | 1 +
25-akpm/drivers/block/pktcdvd.c | 1 +
25-akpm/drivers/ide/ide-io.c | 1 +
25-akpm/drivers/ide/ide-tape.c | 1 +
25-akpm/include/linux/blkdev.h | 11 ++++++++++-
6 files changed, 42 insertions(+), 9 deletions(-)
diff -puN drivers/block/ll_rw_blk.c~add-struct-request-end_io-callback drivers/block/ll_rw_blk.c
--- 25/drivers/block/ll_rw_blk.c~add-struct-request-end_io-callback 2005-02-23 02:11:18.000000000 -0800
+++ 25-akpm/drivers/block/ll_rw_blk.c 2005-02-23 02:11:18.000000000 -0800
@@ -1753,6 +1753,8 @@ rq_starved:
rq->data_len = 0;
rq->data = NULL;
rq->sense = NULL;
+ rq->end_io = NULL;
+ rq->end_io_data = NULL;
out:
put_io_context(ioc);
@@ -2018,8 +2020,8 @@ int blk_execute_rq(request_queue_t *q, s
}
rq->flags |= REQ_NOMERGE;
- if (!rq->waiting)
- rq->waiting = &wait;
+ rq->waiting = &wait;
+ rq->end_io = blk_end_sync_rq;
elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 1);
generic_unplug_device(q);
wait_for_completion(rq->waiting);
@@ -2171,7 +2173,7 @@ void disk_round_stats(struct gendisk *di
/*
* queue lock must be held
*/
-void __blk_put_request(request_queue_t *q, struct request *req)
+static void __blk_put_request(request_queue_t *q, struct request *req)
{
struct request_list *rl = req->rl;
@@ -2219,6 +2221,25 @@ void blk_put_request(struct request *req
EXPORT_SYMBOL(blk_put_request);
/**
+ * blk_end_sync_rq - executes a completion event on a request
+ * @rq: request to complete
+ */
+void blk_end_sync_rq(struct request *rq)
+{
+ struct completion *waiting = rq->waiting;
+
+ rq->waiting = NULL;
+ __blk_put_request(rq->q, rq);
+
+ /*
+ * complete last, if this is a stack request the process (and thus
+ * the rq pointer) could be invalid right after this complete()
+ */
+ complete(waiting);
+}
+EXPORT_SYMBOL(blk_end_sync_rq);
+
+/**
* blk_congestion_wait - wait for a queue to become uncongested
* @rw: READ or WRITE
* @timeout: timeout in jiffies
@@ -2978,7 +2999,6 @@ EXPORT_SYMBOL(end_that_request_chunk);
void end_that_request_last(struct request *req)
{
struct gendisk *disk = req->rq_disk;
- struct completion *waiting = req->waiting;
if (unlikely(laptop_mode) && blk_fs_request(req))
laptop_io_completion();
@@ -2998,10 +3018,10 @@ void end_that_request_last(struct reques
disk_round_stats(disk);
disk->in_flight--;
}
- __blk_put_request(req->q, req);
- /* Do this LAST! The structure may be freed immediately afterwards */
- if (waiting)
- complete(waiting);
+ if (req->end_io)
+ req->end_io(req);
+ else
+ __blk_put_request(req->q, req);
}
EXPORT_SYMBOL(end_that_request_last);
diff -puN drivers/block/paride/pd.c~add-struct-request-end_io-callback drivers/block/paride/pd.c
--- 25/drivers/block/paride/pd.c~add-struct-request-end_io-callback 2005-02-23 02:11:18.000000000 -0800
+++ 25-akpm/drivers/block/paride/pd.c 2005-02-23 02:11:18.000000000 -0800
@@ -743,6 +743,7 @@ static int pd_special_command(struct pd_
rq.rq_disk = disk->gd;
rq.ref_count = 1;
rq.waiting = &wait;
+ rq.end_io = blk_end_sync_rq;
blk_insert_request(disk->gd->queue, &rq, 0, func, 0);
wait_for_completion(&wait);
rq.waiting = NULL;
diff -puN drivers/ide/ide-io.c~add-struct-request-end_io-callback drivers/ide/ide-io.c
--- 25/drivers/ide/ide-io.c~add-struct-request-end_io-callback 2005-02-23 02:11:18.000000000 -0800
+++ 25-akpm/drivers/ide/ide-io.c 2005-02-23 02:11:18.000000000 -0800
@@ -1835,6 +1835,7 @@ int ide_do_drive_cmd (ide_drive_t *drive
if (must_wait) {
rq->ref_count++;
rq->waiting = &wait;
+ rq->end_io = blk_end_sync_rq;
}
spin_lock_irqsave(&ide_lock, flags);
diff -puN drivers/ide/ide-tape.c~add-struct-request-end_io-callback drivers/ide/ide-tape.c
--- 25/drivers/ide/ide-tape.c~add-struct-request-end_io-callback 2005-02-23 02:11:18.000000000 -0800
+++ 25-akpm/drivers/ide/ide-tape.c 2005-02-23 02:11:18.000000000 -0800
@@ -2766,6 +2766,7 @@ static void idetape_wait_for_request (id
}
#endif /* IDETAPE_DEBUG_BUGS */
rq->waiting = &wait;
+ rq->end_io = blk_end_sync_rq;
spin_unlock_irq(&tape->spinlock);
wait_for_completion(&wait);
/* The stage and its struct request have been deallocated */
diff -puN include/linux/blkdev.h~add-struct-request-end_io-callback include/linux/blkdev.h
--- 25/include/linux/blkdev.h~add-struct-request-end_io-callback 2005-02-23 02:11:18.000000000 -0800
+++ 25-akpm/include/linux/blkdev.h 2005-02-23 02:11:18.000000000 -0800
@@ -93,6 +93,9 @@ struct io_context *get_io_context(int gf
void copy_io_context(struct io_context **pdst, struct io_context **psrc);
void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
+struct request;
+typedef void (rq_end_io_fn)(struct request *);
+
struct request_list {
int count[2];
int starved[2];
@@ -176,6 +179,12 @@ struct request {
* For Power Management requests
*/
struct request_pm_state *pm;
+
+ /*
+ * completion callback. end_io_data should be folded in with waiting
+ */
+ rq_end_io_fn *end_io;
+ void *end_io_data;
};
/*
@@ -509,10 +518,10 @@ extern void blk_unregister_queue(struct
extern void register_disk(struct gendisk *dev);
extern void generic_make_request(struct bio *bio);
extern void blk_put_request(struct request *);
+extern void blk_end_sync_rq(struct request *rq);
extern void blk_attempt_remerge(request_queue_t *, struct request *);
extern void __blk_attempt_remerge(request_queue_t *, struct request *);
extern struct request *blk_get_request(request_queue_t *, int, int);
-extern void blk_put_request(struct request *);
extern void blk_insert_request(request_queue_t *, struct request *, int, void *, int);
extern void blk_requeue_request(request_queue_t *, struct request *);
extern void blk_plug_device(request_queue_t *);
diff -puN drivers/block/pktcdvd.c~add-struct-request-end_io-callback drivers/block/pktcdvd.c
--- 25/drivers/block/pktcdvd.c~add-struct-request-end_io-callback 2005-02-23 02:11:20.000000000 -0800
+++ 25-akpm/drivers/block/pktcdvd.c 2005-02-23 02:11:20.000000000 -0800
@@ -375,6 +375,7 @@ static int pkt_generic_packet(struct pkt
rq->ref_count++;
rq->flags |= REQ_NOMERGE;
rq->waiting = &wait;
+ rq->end_io = blk_end_sync_rq;
elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 1);
generic_unplug_device(q);
wait_for_completion(&wait);
_