dm mpath: remove unnecessary memset() calls for per-io-data

All underlying members are initialized directly so the memset() calls
are not needed.  Also, initialize mpio->nr_bytes from the start since it
never changes.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 8ed72275026d0b1774ca58c5927d3b7e875e696d..a3acbfb638be4904e8db440ed58843a659767449 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -278,12 +278,11 @@ static void multipath_init_per_bio_data(struct bio *bio, struct dm_mpath_io **mp
        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));
-       memset(bio_details, 0, sizeof(*bio_details));
-       dm_bio_record(bio_details, bio);
+       mpio->nr_bytes = bio->bi_iter.bi_size;
+       mpio->pgpath = NULL;
+       *mpio_p = mpio;
 
-       if (mpio_p)
-               *mpio_p = mpio;
+       dm_bio_record(bio_details, bio);
 }
 
 /*-----------------------------------------------
@@ -518,7 +517,6 @@ static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
                return DM_MAPIO_REQUEUE;
        }
 
-       memset(mpio, 0, sizeof(*mpio));
        mpio->pgpath = pgpath;
        mpio->nr_bytes = nr_bytes;
 
@@ -556,7 +554,6 @@ static void multipath_release_clone(struct request *clone)
  */
 static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_mpath_io *mpio)
 {
-       size_t nr_bytes = bio->bi_iter.bi_size;
        struct pgpath *pgpath;
        unsigned long flags;
        bool queue_io;
@@ -565,7 +562,7 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
        pgpath = READ_ONCE(m->current_pgpath);
        queue_io = test_bit(MPATHF_QUEUE_IO, &m->flags);
        if (!pgpath || !queue_io)
-               pgpath = choose_pgpath(m, nr_bytes);
+               pgpath = choose_pgpath(m, mpio->nr_bytes);
 
        if ((pgpath && queue_io) ||
            (!pgpath && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))) {
@@ -589,7 +586,6 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
        }
 
        mpio->pgpath = pgpath;
-       mpio->nr_bytes = nr_bytes;
 
        bio->bi_status = 0;
        bio_set_dev(bio, pgpath->path.dev->bdev);
@@ -598,7 +594,7 @@ static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_m
        if (pgpath->pg->ps.type->start_io)
                pgpath->pg->ps.type->start_io(&pgpath->pg->ps,
                                              &pgpath->path,
-                                             nr_bytes);
+                                             mpio->nr_bytes);
        return DM_MAPIO_REMAPPED;
 }