This is a note to let you know that I've just added the patch titled
btrfs: add a helper to read the superblock metadata_uuid
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-add-a-helper-to-read-the-superblock-metadata_u.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d0ab1ea6d4131b35e1164afc1b4315627320ed1e
Author: Anand Jain <anand.jain@xxxxxxxxxx>
Date: Mon Jul 31 19:16:32 2023 +0800
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@xxxxxxx>
Tested-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx>
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Stable-dep-of: 6bfe3959b0e7 ("btrfs: compare the correct fsid/metadata_uuid in btrfs_validate_super")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0d4afeacb237b..f9192dcb9208b 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -895,6 +895,14 @@ 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.
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index fd8fdaa4b0cdf..762c0a3754982 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -582,5 +582,6 @@ const char *btrfs_bg_type_to_raid_name(u64 flags);
int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
+u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb);
#endif
