diff options
Diffstat (limited to 'lib/btrfs/btrfsitem/item_chunk.go')
| -rw-r--r-- | lib/btrfs/btrfsitem/item_chunk.go | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/lib/btrfs/btrfsitem/item_chunk.go b/lib/btrfs/btrfsitem/item_chunk.go index 2280a0b..607df75 100644 --- a/lib/btrfs/btrfsitem/item_chunk.go +++ b/lib/btrfs/btrfsitem/item_chunk.go @@ -11,10 +11,20 @@ import ( "git.lukeshu.com/btrfs-progs-ng/lib/containers" ) -// Maps logical address to physical. +// A Chunk maps logical addresses to physical addresses. // -// key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID -// key.offset = logical_addr +// Compare with: +// - DevExtents, which track allocation of the physical address space. +// - BlockGroups, which track allocation of the logical address space. +// +// The relationship between the three is +// +// DevExtent---[many:one]---Chunk---[one:one]---BlockGroup +// +// Key: +// +// key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID +// key.offset = logical_addr type Chunk struct { // complex CHUNK_ITEM=228 Head ChunkHeader Stripes []ChunkStripe |