This is a note to let you know that I've just added the patch titled
dm mpath: pass IO start time to path selector
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-mpath-pass-io-start-time-to-path-selector.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a82d33934515ca591b0746a08889aa2c6bfc2187
Author: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Date: Thu Apr 30 16:48:29 2020 -0400
dm mpath: pass IO start time to path selector
[ Upstream commit 087615bf3acdafd0ba7c7c9ed5286e7b7c80fe1b ]
The HST path selector needs this information to perform path
prediction. For request-based mpath, struct request's io_start_time_ns
is used, while for bio-based, use the start_time stored in dm_io.
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Stable-dep-of: 1e1fd567d32f ("dm suspend: return -ERESTARTSYS instead of -EINTR")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 54ecfea2cf47b..4f6a54452b1ca 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -558,7 +558,8 @@ static void multipath_release_clone(struct request *clone,
if (pgpath && pgpath->pg->ps.type->end_io)
pgpath->pg->ps.type->end_io(&pgpath->pg->ps,
&pgpath->path,
- mpio->nr_bytes);
+ mpio->nr_bytes,
+ clone->io_start_time_ns);
}
blk_put_request(clone);
@@ -1568,7 +1569,8 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone,
struct path_selector *ps = &pgpath->pg->ps;
if (ps->type->end_io)
- ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes);
+ ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes,
+ clone->io_start_time_ns);
}
return r;
@@ -1612,7 +1614,8 @@ static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone,
struct path_selector *ps = &pgpath->pg->ps;
if (ps->type->end_io)
- ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes);
+ ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes,
+ dm_start_time_ns_from_clone(clone));
}
return r;
diff --git a/drivers/md/dm-path-selector.h b/drivers/md/dm-path-selector.h
index b6eb5365b1a46..c47bc0e20275b 100644
--- a/drivers/md/dm-path-selector.h
+++ b/drivers/md/dm-path-selector.h
@@ -74,7 +74,7 @@ struct path_selector_type {
int (*start_io) (struct path_selector *ps, struct dm_path *path,
size_t nr_bytes);
int (*end_io) (struct path_selector *ps, struct dm_path *path,
- size_t nr_bytes);
+ size_t nr_bytes, u64 start_time);
};
/* Register a path selector */
diff --git a/drivers/md/dm-queue-length.c b/drivers/md/dm-queue-length.c
index 969c4f1a36336..5fd018d184187 100644
--- a/drivers/md/dm-queue-length.c
+++ b/drivers/md/dm-queue-length.c
@@ -227,7 +227,7 @@ static int ql_start_io(struct path_selector *ps, struct dm_path *path,
}
static int ql_end_io(struct path_selector *ps, struct dm_path *path,
- size_t nr_bytes)
+ size_t nr_bytes, u64 start_time)
{
struct path_info *pi = path->pscontext;
diff --git a/drivers/md/dm-service-time.c b/drivers/md/dm-service-time.c
index f006a9005593b..9cfda665e9ebd 100644
--- a/drivers/md/dm-service-time.c
+++ b/drivers/md/dm-service-time.c
@@ -309,7 +309,7 @@ static int st_start_io(struct path_selector *ps, struct dm_path *path,
}
static int st_end_io(struct path_selector *ps, struct dm_path *path,
- size_t nr_bytes)
+ size_t nr_bytes, u64 start_time)
{
struct path_info *pi = path->pscontext;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index a7724ba45b437..36d21a5d09ebf 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -659,6 +659,15 @@ static bool md_in_flight(struct mapped_device *md)
return md_in_flight_bios(md);
}
+u64 dm_start_time_ns_from_clone(struct bio *bio)
+{
+ struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
+ struct dm_io *io = tio->io;
+
+ return jiffies_to_nsecs(io->start_time);
+}
+EXPORT_SYMBOL_GPL(dm_start_time_ns_from_clone);
+
static void start_io_acct(struct dm_io *io)
{
struct mapped_device *md = io->md;
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 60631f3abddbd..b077f32043653 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -332,6 +332,8 @@ void *dm_per_bio_data(struct bio *bio, size_t data_size);
struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size);
unsigned dm_bio_get_target_bio_nr(const struct bio *bio);
+u64 dm_start_time_ns_from_clone(struct bio *bio);
+
int dm_register_target(struct target_type *t);
void dm_unregister_target(struct target_type *t);
