Btrfs: Remove the check for old-style mkfs

This was used to make sure that a fresh btrfs from an older mkfs.btrfs,
but it also allows us to mount a buggy btrfs if this btrfs has the right
superblock head part but has something wrong with chunk tree part[1], and
after that we can hit BUG_ON()s set in the code to prevent something
impossible.

Since David has released "Btrfs progs v3.19-rc2", just remove the check,
if anyone who wants to make a fresh btrfs, please use the latest one.

[1]: http://www.spinics.net/lists/linux-btrfs/msg42358.html

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Omar Sandoval <osandov@osandov.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit e56a951e01bf55f49533c47ad2ce61dbd613a3f3)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 04cc9d9a689d4d76ee8661b538ca2ceeb01934c0..d532e4215f05a9826b82880198cb7e7ad1b26e64 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -419,12 +419,6 @@ static int btrfs_check_super_csum(char *raw_disk_sb)
 
                if (memcmp(raw_disk_sb, result, csum_size))
                        ret = 1;
-
-               if (ret && btrfs_super_generation(disk_sb) < 10) {
-                       printk(KERN_WARNING
-                               "BTRFS: super block crcs don't match, older mkfs detected\n");
-                       ret = 0;
-               }
        }
 
        if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {