From 06496c9fa2f993998b88acfb9f7f0f407d465fff Mon Sep 17 00:00:00 2001
From: Anand Jain <anand.jain@oracle.com>
Date: Mon, 31 Jul 2023 19:16:32 +0800
Subject: [PATCH] btrfs: add a helper to read the superblock metadata_uuid
[ Upstream commit 4844c3664a72d36cc79752cb651c78860b14c240 ]
In some cases, we need to read the FSID from the superblock when the
metadata_uuid is not set, and otherwise, read the metadata_uuid. So,
add a helper.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 6bfe3959b0e7 ("btrfs: compare the correct fsid/metadata_uuid in btrfs_validate_super")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/volumes.c | 8 ++++++++
fs/btrfs/volumes.h | 1 +
2 files changed, 9 insertions(+)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6aa9bf3661ac8..51070c0d4141e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -681,6 +681,14 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
return -EINVAL;
}
+u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb)
+{
+ bool has_metadata_uuid = (btrfs_super_incompat_flags(sb) &
+ BTRFS_FEATURE_INCOMPAT_METADATA_UUID);
+
+ return has_metadata_uuid ? sb->metadata_uuid : sb->fsid;
+}
+
/*
* Handle scanned device having its CHANGING_FSID_V2 flag set and the fs_devices
* being created with a disk that has already completed its fsid change. Such
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index b8c51f16ba867..0f87057bb575f 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -749,5 +749,6 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
+u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb);
#endif