btrfs: cleanup: use for() loop in btrfs_map_bio()

for() is obviously better in these code block, and remove noused
init-value to reduce about 6 bytes binary size.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.cz>

1 files changed, 3 insertions, 6 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 30c6074f3d00..d7d1dde5f2ff 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5820,8 +5820,8 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
         u64 length = 0;
         u64 map_length;
         int ret;
-        int dev_nr = 0;
-        int total_devs = 1;
+        int dev_nr;
+        int total_devs;
         struct btrfs_bio *bbio = NULL;
 
         length = bio->bi_iter.bi_size;
@@ -5862,11 +5862,10 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
                 BUG();
         }
 
-        while (dev_nr < total_devs) {
+        for (dev_nr = 0; dev_nr < total_devs; dev_nr++) {
                 dev = bbio->stripes[dev_nr].dev;
                 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
                         bbio_error(bbio, first_bio, logical);
-                        dev_nr++;
                         continue;
                 }
 
@@ -5879,7 +5878,6 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
                         ret = breakup_stripe_bio(root, bbio, first_bio, dev,
                                                  dev_nr, rw, async_submit);
                         BUG_ON(ret);
-                        dev_nr++;
                         continue;
                 }
 
@@ -5894,7 +5892,6 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
                 submit_stripe_bio(root, bbio, bio,
                                   bbio->stripes[dev_nr].physical, dev_nr, rw,
                                   async_submit);
-                dev_nr++;
         }
         btrfs_bio_counter_dec(root->fs_info);
         return 0;