dm mpath: remove bio-based bloat from struct dm_mpath_io
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index f592166..2d10ff7 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -109,11 +109,6 @@
struct dm_mpath_io {
struct pgpath *pgpath;
size_t nr_bytes;
-
- /*
- * FIXME: make request-based code _not_ include this member.
- */
- struct dm_bio_details bio_details;
};
typedef int (*action_fn) (struct pgpath *pgpath);
@@ -294,19 +289,39 @@
}
}
-static struct dm_mpath_io *get_mpio_from_bio(struct bio *bio)
+static size_t multipath_per_bio_data_size(void)
{
- return dm_per_bio_data(bio, sizeof(struct dm_mpath_io));
+ return sizeof(struct dm_mpath_io) + sizeof(struct dm_bio_details);
}
-static struct dm_mpath_io *set_mpio_bio(struct multipath *m, struct bio *bio)
+static struct dm_mpath_io *get_mpio_from_bio(struct bio *bio)
+{
+ return dm_per_bio_data(bio, multipath_per_bio_data_size());
+}
+
+static struct dm_bio_details *get_bio_details_from_bio(struct bio *bio)
+{
+ /* dm_bio_details is immediately after the dm_mpath_io in bio's per-bio-data */
+ struct dm_mpath_io *mpio = get_mpio_from_bio(bio);
+ void *bio_details = mpio + 1;
+
+ return bio_details;
+}
+
+static void multipath_init_per_bio_data(struct bio *bio, struct dm_mpath_io **mpio_p,
+ struct dm_bio_details **bio_details_p)
{
struct dm_mpath_io *mpio = get_mpio_from_bio(bio);
+ struct dm_bio_details *bio_details = get_bio_details_from_bio(bio);
memset(mpio, 0, sizeof(*mpio));
- dm_bio_record(&mpio->bio_details, bio);
+ memset(bio_details, 0, sizeof(*bio_details));
+ dm_bio_record(bio_details, bio);
- return mpio;
+ if (mpio_p)
+ *mpio_p = mpio;
+ if (bio_details_p)
+ *bio_details_p = bio_details;
}
/*-----------------------------------------------
@@ -629,7 +644,9 @@
static int multipath_map_bio(struct dm_target *ti, struct bio *bio)
{
struct multipath *m = ti->private;
- struct dm_mpath_io *mpio = set_mpio_bio(m, bio);
+ struct dm_mpath_io *mpio = NULL;
+
+ multipath_init_per_bio_data(bio, &mpio, NULL);
return __multipath_map_bio(m, bio, mpio);
}
@@ -1113,7 +1130,9 @@
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->num_write_same_bios = 1;
- if (use_blk_mq || bio_based)
+ if (bio_based)
+ ti->per_io_data_size = multipath_per_bio_data_size();
+ else if (use_blk_mq)
ti->per_io_data_size = sizeof(struct dm_mpath_io);
return 0;
@@ -1576,7 +1595,7 @@
}
/* Queue for the daemon to resubmit */
- dm_bio_restore(&mpio->bio_details, clone);
+ dm_bio_restore(get_bio_details_from_bio(clone), clone);
spin_lock_irqsave(&m->lock, flags);
bio_list_add(&m->queued_bios, clone);