[PATCH 1/3] btrfs: Add incompat flags check for btrfs_check_super_valid()

Qu Wenruo
2018-04-19T09:38:27Z

Although we have already checked incompat flags manually before really
mounting it, we could still enhance btrfs_check_super_valid() to check
incompat flags for later write time super block validation check.

This patch adds such incompat flags check for btrfs_check_super_valid(),
currently it won't be triggered, but provides the basis for later write
time check.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/disk-io.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 60caa68c3618..ec123158f051 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
ret = -EINVAL;
}

+ /*
+ * Before calling btrfs_check_super_valid() we have already checked
+ * incompat flags. So if we developr new incompat flags, it's must be
+ * some corruption.
+ */
+ if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
+ btrfs_err(fs_info,
+ "corrupted incompat flags detected 0x%llx, supported 0x%llx",
+ btrfs_super_incompat_flags(sb),
+ BTRFS_FEATURE_INCOMPAT_SUPP);
+ ret = -EINVAL;
+ }
+
/*
* The generation is a global counter, we'll trust it more than the others
* but it's still possible that it's the one that's wrong.
--
2.17.0