diff options
| author | Mark Harmstone <mark@harmstone.com> | 2026-01-07 14:09:02 +0000 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2026-02-03 07:54:27 +0100 |
| commit | 0b4d29fa98ca1a49c4498353253f857573871ba0 (patch) | |
| tree | 0de2957d4eb36cad681d2fcb7004ef1a40e2804a /include | |
| parent | ef6a31d035a1000071dc4846aebd02ad081db9e4 (diff) | |
btrfs: add METADATA_REMAP chunk type
Add a new METADATA_REMAP chunk type, which is a metadata chunk that holds the
remap tree.
This is needed for bootstrapping purposes: the remap tree can't itself
be remapped, and must be relocated the existing way, by COWing every
leaf. The remap tree can't go in the SYSTEM chunk as space there is
limited, because a copy of the chunk item gets placed in the superblock.
The changes in fs/btrfs/volumes.h are because we're adding a new block
group type bit after the profile bits, and so can no longer rely on the
const_ilog2 trick.
The sizing to 32MB per chunk, matching the SYSTEM chunk, is an estimate
here, we can adjust it later if it proves to be too big or too small.
This works out to be ~500,000 remap items, which for a 4KB block size
covers ~2GB of remapped data in the worst case and ~500TB in the best case.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/btrfs_tree.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h index f011d34cb699..76578426671c 100644 --- a/include/uapi/linux/btrfs_tree.h +++ b/include/uapi/linux/btrfs_tree.h @@ -1169,12 +1169,14 @@ struct btrfs_dev_replace_item { #define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9) #define BTRFS_BLOCK_GROUP_RAID1C4 (1ULL << 10) #define BTRFS_BLOCK_GROUP_REMAPPED (1ULL << 11) +#define BTRFS_BLOCK_GROUP_METADATA_REMAP (1ULL << 12) #define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \ BTRFS_SPACE_INFO_GLOBAL_RSV) #define BTRFS_BLOCK_GROUP_TYPE_MASK (BTRFS_BLOCK_GROUP_DATA | \ BTRFS_BLOCK_GROUP_SYSTEM | \ - BTRFS_BLOCK_GROUP_METADATA) + BTRFS_BLOCK_GROUP_METADATA | \ + BTRFS_BLOCK_GROUP_METADATA_REMAP) #define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \ BTRFS_BLOCK_GROUP_RAID1 | \ |