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authorMikulas Patocka <mpatocka@redhat.com>2015-06-09 17:22:49 -0400
committerMike Snitzer <snitzer@redhat.com>2015-06-17 12:40:41 -0400
commite262f34741522e0d821642e5449c6eeb512723fc (patch)
tree2f6608a34b9b1ef4c249267901d73a5e0d481cd0 /drivers/md/dm.c
parentdfcfac3e4cd94abef779297fab6adfd2dbcf52fa (diff)
dm stats: add support for request-based DM devices
This makes it possible to use dm stats with DM multipath. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 767bce906588..90dc49e3c78f 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -86,6 +86,9 @@ struct dm_rq_target_io {
struct kthread_work work;
int error;
union map_info info;
+ struct dm_stats_aux stats_aux;
+ unsigned long duration_jiffies;
+ unsigned n_sectors;
};
/*
@@ -995,6 +998,17 @@ static struct dm_rq_target_io *tio_from_request(struct request *rq)
return (rq->q->mq_ops ? blk_mq_rq_to_pdu(rq) : rq->special);
}
+static void rq_end_stats(struct mapped_device *md, struct request *orig)
+{
+ if (unlikely(dm_stats_used(&md->stats))) {
+ struct dm_rq_target_io *tio = tio_from_request(orig);
+ tio->duration_jiffies = jiffies - tio->duration_jiffies;
+ dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig),
+ tio->n_sectors, true, tio->duration_jiffies,
+ &tio->stats_aux);
+ }
+}
+
/*
* Don't touch any member of the md after calling this function because
* the md may be freed in dm_put() at the end of this function.
@@ -1078,6 +1092,7 @@ static void dm_end_request(struct request *clone, int error)
}
free_rq_clone(clone);
+ rq_end_stats(md, rq);
if (!rq->q->mq_ops)
blk_end_request_all(rq, error);
else
@@ -1120,6 +1135,7 @@ static void dm_requeue_original_request(struct mapped_device *md,
dm_unprep_request(rq);
+ rq_end_stats(md, rq);
if (!rq->q->mq_ops)
old_requeue_request(rq);
else {
@@ -1211,6 +1227,7 @@ static void dm_softirq_done(struct request *rq)
int rw;
if (!clone) {
+ rq_end_stats(tio->md, rq);
rw = rq_data_dir(rq);
if (!rq->q->mq_ops) {
blk_end_request_all(rq, tio->error);
@@ -1943,6 +1960,14 @@ static void dm_start_request(struct mapped_device *md, struct request *orig)
md->last_rq_start_time = ktime_get();
}
+ if (unlikely(dm_stats_used(&md->stats))) {
+ struct dm_rq_target_io *tio = tio_from_request(orig);
+ tio->duration_jiffies = jiffies;
+ tio->n_sectors = blk_rq_sectors(orig);
+ dm_stats_account_io(&md->stats, orig->cmd_flags, blk_rq_pos(orig),
+ tio->n_sectors, false, 0, &tio->stats_aux);
+ }
+
/*
* Hold the md reference here for the in-flight I/O.
* We can't rely on the reference count by device opener,
@@ -2689,6 +2714,7 @@ static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
/* Direct call is fine since .queue_rq allows allocations */
if (map_request(tio, rq, md) == DM_MAPIO_REQUEUE) {
/* Undo dm_start_request() before requeuing */
+ rq_end_stats(md, rq);
rq_completed(md, rq_data_dir(rq), false);
return BLK_MQ_RQ_QUEUE_BUSY;
}