Btrfs: superblock duplication
authorYan Zheng <zheng.yan@oracle.com>
Mon, 8 Dec 2008 21:46:26 +0000 (16:46 -0500)
committerChris Mason <chris.mason@oracle.com>
Mon, 8 Dec 2008 21:46:26 +0000 (16:46 -0500)
commita512bbf855ff0af474257475f2e6da7acd854f52
tree1b2cfcf4152e09f32a6cb0bcbd798d5dab2f5490
parentd20f7043fa65659136c1a7c3c456eeeb5c6f431f
Btrfs: superblock duplication

This patch implements superblock duplication. Superblocks
are stored at offset 16K, 64M and 256G on every devices.
Spaces used by superblocks are preserved by the allocator,
which uses a reverse mapping function to find the logical
addresses that correspond to superblocks. Thank you,

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
fs/btrfs/disk-io.c
fs/btrfs/disk-io.h
fs/btrfs/extent-tree.c
fs/btrfs/free-space-cache.c
fs/btrfs/transaction.c
fs/btrfs/tree-log.c
fs/btrfs/volumes.c
fs/btrfs/volumes.h