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authorLars Ellenberg <lars.ellenberg@linbit.com>2013-03-19 18:16:50 +0100
committerJens Axboe <axboe@kernel.dk>2013-03-22 18:14:00 -0600
commit6d9febe237146156947f0da8407c620b5c33c1df (patch)
treef1839ad3ba66f255581b2f9e68b29d5a78c40642 /drivers/block/drbd/drbd_req.c
parentebfd5d8f715167b886c9401e6b123847187f137b (diff)
downloadvexpress-lsk-6d9febe237146156947f0da8407c620b5c33c1df.tar.gz
drbd: split __drbd_make_request in before and after drbd_al_begin_io
This is in preparation to be able to defer requests that need to wait for an activity log transaction to a submitter workqueue. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/drbd/drbd_req.c')
-rw-r--r--drivers/block/drbd/drbd_req.c40
1 files changed, 30 insertions, 10 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 7d1ff1aaeb7..96d5968fc1e 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -34,14 +34,14 @@
static bool drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int size);
/* Update disk stats at start of I/O request */
-static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req, struct bio *bio)
+static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req)
{
- const int rw = bio_data_dir(bio);
+ const int rw = bio_data_dir(req->master_bio);
int cpu;
cpu = part_stat_lock();
part_round_stats(cpu, &mdev->vdisk->part0);
part_stat_inc(cpu, &mdev->vdisk->part0, ios[rw]);
- part_stat_add(cpu, &mdev->vdisk->part0, sectors[rw], bio_sectors(bio));
+ part_stat_add(cpu, &mdev->vdisk->part0, sectors[rw], req->i.size >> 9);
(void) cpu; /* The macro invocations above want the cpu argument, I do not like
the compiler warning about cpu only assigned but never used... */
part_inc_in_flight(&mdev->vdisk->part0, rw);
@@ -1020,12 +1020,16 @@ drbd_submit_req_private_bio(struct drbd_request *req)
bio_endio(bio, -EIO);
}
-void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time)
+/* returns the new drbd_request pointer, if the caller is expected to
+ * drbd_send_and_submit() it (to save latency), or NULL if we queued the
+ * request on the submitter thread.
+ * Returns ERR_PTR(-ENOMEM) if we cannot allocate a drbd_request.
+ */
+struct drbd_request *
+drbd_request_prepare(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time)
{
- const int rw = bio_rw(bio);
- struct bio_and_error m = { NULL, };
+ const int rw = bio_data_dir(bio);
struct drbd_request *req;
- bool no_remote = false;
/* allocate outside of all locks; */
req = drbd_req_new(mdev, bio);
@@ -1035,7 +1039,7 @@ void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long
* if user cannot handle io errors, that's not our business. */
dev_err(DEV, "could not kmalloc() req\n");
bio_endio(bio, -ENOMEM);
- return;
+ return ERR_PTR(-ENOMEM);
}
req->start_time = start_time;
@@ -1057,6 +1061,15 @@ void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long
drbd_al_begin_io(mdev, &req->i, true);
}
+ return req;
+}
+
+static void drbd_send_and_submit(struct drbd_conf *mdev, struct drbd_request *req)
+{
+ const int rw = bio_rw(req->master_bio);
+ struct bio_and_error m = { NULL, };
+ bool no_remote = false;
+
spin_lock_irq(&mdev->tconn->req_lock);
if (rw == WRITE) {
/* This may temporarily give up the req_lock,
@@ -1079,7 +1092,7 @@ void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long
}
/* Update disk stats */
- _drbd_start_io_acct(mdev, req, bio);
+ _drbd_start_io_acct(mdev, req);
/* We fail READ/READA early, if we can not serve it.
* We must do this before req is registered on any lists.
@@ -1137,7 +1150,14 @@ out:
if (m.bio)
complete_master_bio(mdev, &m);
- return;
+}
+
+void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long start_time)
+{
+ struct drbd_request *req = drbd_request_prepare(mdev, bio, start_time);
+ if (IS_ERR_OR_NULL(req))
+ return;
+ drbd_send_and_submit(mdev, req);
}
void drbd_make_request(struct request_queue *q, struct bio *bio)