summaryrefslogtreecommitdiff
path: root/drivers/md/dm-delay.c
diff options
context:
space:
mode:
authorMikulas Patocka <mpatocka@redhat.com>2018-04-17 00:33:14 +0200
committerMike Snitzer <snitzer@redhat.com>2018-07-27 15:24:19 -0400
commitcda6b5ab7f5935565ed5b9bbc385bd1d0a3feb75 (patch)
treef9874d8e3e6d0f6dbefcba98c6835f37694f6009 /drivers/md/dm-delay.c
parent3876ac76f02ac2a7b3d96f813c0ee1070e7a8c8e (diff)
dm delay: add flush as a third class of IO
Add a new class for dm-delay that delays flush requests. Previously, flushes were delayed as writes, but it caused problems if the user needed to create a device with one or a few slow sectors for the purpose of testing - all flushes would be forwarded to this device and delayed, and that skews the test results. Fix this by allowing to select 0 delay for flushes. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-delay.c')
-rw-r--r--drivers/md/dm-delay.c34
1 files changed, 30 insertions, 4 deletions
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index c5ebe56bc28b..2fb7bb4304ad 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -34,6 +34,7 @@ struct delay_c {
struct delay_class read;
struct delay_class write;
+ struct delay_class flush;
int argc;
};
@@ -126,6 +127,8 @@ static void delay_dtr(struct dm_target *ti)
dm_put_device(ti, dc->read.dev);
if (dc->write.dev)
dm_put_device(ti, dc->write.dev);
+ if (dc->flush.dev)
+ dm_put_device(ti, dc->flush.dev);
mutex_destroy(&dc->timer_lock);
@@ -171,8 +174,8 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
struct delay_c *dc;
int ret;
- if (argc != 3 && argc != 6) {
- ti->error = "Requires exactly 3 or 6 arguments";
+ if (argc != 3 && argc != 6 && argc != 9) {
+ ti->error = "Requires exactly 3, 6 or 9 arguments";
return -EINVAL;
}
@@ -198,12 +201,25 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ret = delay_class_ctr(ti, &dc->write, argv);
if (ret)
goto bad;
+ ret = delay_class_ctr(ti, &dc->flush, argv);
+ if (ret)
+ goto bad;
goto out;
}
ret = delay_class_ctr(ti, &dc->write, argv + 3);
if (ret)
goto bad;
+ if (argc == 6) {
+ ret = delay_class_ctr(ti, &dc->flush, argv + 3);
+ if (ret)
+ goto bad;
+ goto out;
+ }
+
+ ret = delay_class_ctr(ti, &dc->flush, argv + 6);
+ if (ret)
+ goto bad;
out:
dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
@@ -269,7 +285,10 @@ static int delay_map(struct dm_target *ti, struct bio *bio)
struct dm_delay_info *delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
if (bio_data_dir(bio) == WRITE) {
- c = &dc->write;
+ if (unlikely(bio->bi_opf & REQ_PREFLUSH))
+ c = &dc->flush;
+ else
+ c = &dc->write;
} else {
c = &dc->read;
}
@@ -292,7 +311,7 @@ static void delay_status(struct dm_target *ti, status_type_t type,
switch (type) {
case STATUSTYPE_INFO:
- DMEMIT("%u %u", dc->read.ops, dc->write.ops);
+ DMEMIT("%u %u %u", dc->read.ops, dc->write.ops, dc->flush.ops);
break;
case STATUSTYPE_TABLE:
@@ -301,6 +320,10 @@ static void delay_status(struct dm_target *ti, status_type_t type,
DMEMIT(" ");
DMEMIT_DELAY_CLASS(&dc->write);
}
+ if (dc->argc >= 9) {
+ DMEMIT(" ");
+ DMEMIT_DELAY_CLASS(&dc->flush);
+ }
break;
}
}
@@ -317,6 +340,9 @@ static int delay_iterate_devices(struct dm_target *ti,
ret = fn(ti, dc->write.dev, dc->write.start, ti->len, data);
if (ret)
goto out;
+ ret = fn(ti, dc->flush.dev, dc->flush.start, ti->len, data);
+ if (ret)
+ goto out;
out:
return ret;