[PATCH] Revert "Btrfs: allow superblock mismatch from older mkfs"

[Liu Bo <bo.li.liu@oracle.com>]

This reverts commit 667e7d94a1683661cff5fe9a0fa0d7f8fdd2c007.

This was used to make sure that a fresh btrfs from an older mkfs.btrfs,
and 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 gave us "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>

Conflicts:
	fs/btrfs/disk-io.c
---
 fs/btrfs/disk-io.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 41b320e..f63aacf 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -418,12 +418,6 @@ 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)) {
-- 
1.8.1.4