[PATCH AUTOSEL for 4.15 064/189] btrfs: fail mount when sb flag is not in BTRFS_SUPER_FLAG_SUPP

[Sasha Levin]

From: Anand Jain <anand.j...@oracle.com>

[ Upstream commit 6f794e3c5c8f8fdd3b5bb20d9ded894e685b5bbe ]

It appears from the original commit [1] that there isn't any design
specific reason not to fail the mount instead of just warning. This
patch will change it to fail.

[1]
 commit 319e4d0661e5323c9f9945f0f8fb5905e5fe74c3
    btrfs: Enhance super validation check

Fixes: 319e4d0661e5323 ("btrfs: Enhance super validation check")
Signed-off-by: Anand Jain <anand.j...@oracle.com>
Reviewed-by: Qu Wenruo <w...@suse.com>
Reviewed-by: David Sterba <dste...@suse.com>
Signed-off-by: David Sterba <dste...@suse.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
---
 fs/btrfs/disk-io.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a8ecccfc36de..3353d3de726a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3910,9 +3910,11 @@ static int btrfs_check_super_valid(struct btrfs_fs_info 
*fs_info)
                btrfs_err(fs_info, "no valid FS found");
                ret = -EINVAL;
        }
-       if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP)
-               btrfs_warn(fs_info, "unrecognized super flag: %llu",
+       if (btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP) {
+               btrfs_err(fs_info, "unrecognized or unsupported super flag: 
%llu",
                                btrfs_super_flags(sb) & ~BTRFS_SUPER_FLAG_SUPP);
+               ret = -EINVAL;
+       }
        if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
                btrfs_err(fs_info, "tree_root level too big: %d >= %d",
                                btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
-- 
2.15.1