Currently this function executes the inner loop at most 1 due to the i = 0;
i < 1 condition. Furthermore, the btrfs_super_generation(super) > transid code
in the if condition is never executed due to latest always set to NULL hence the
first part of the condition always triggering. The gist of btrfs_read_dev_super
is really to read the first superblock.

Signed-off-by: Nikolay Borisov <nbori...@suse.com>
---
 fs/btrfs/disk-io.c | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 82c96607fc46..6d5f632fd1e7 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3170,37 +3170,18 @@ int btrfs_read_dev_one_super(struct block_device *bdev, 
int copy_num,
 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
 {
        struct buffer_head *bh;
-       struct buffer_head *latest = NULL;
-       struct btrfs_super_block *super;
-       int i;
-       u64 transid = 0;
-       int ret = -EINVAL;
+       int ret;
 
        /* we would like to check all the supers, but that would make
         * a btrfs mount succeed after a mkfs from a different FS.
         * So, we need to add a special mount option to scan for
         * later supers, using BTRFS_SUPER_MIRROR_MAX instead
         */
-       for (i = 0; i < 1; i++) {
-               ret = btrfs_read_dev_one_super(bdev, i, &bh);
-               if (ret)
-                       continue;
-
-               super = (struct btrfs_super_block *)bh->b_data;
-
-               if (!latest || btrfs_super_generation(super) > transid) {
-                       brelse(latest);
-                       latest = bh;
-                       transid = btrfs_super_generation(super);
-               } else {
-                       brelse(bh);
-               }
-       }
-
-       if (!latest)
+       ret = btrfs_read_dev_one_super(bdev, 0, &bh);
+       if (ret)
                return ERR_PTR(ret);
 
-       return latest;
+       return bh;
 }
 
 /*
-- 
2.7.4

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