From 0bd93ba022f5c1ddb4e5b722b02f3c4a4a8865ad Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 11 Apr 2007 13:57:44 -0400 Subject: [PATCH] Btrfs: early support for multiple devices Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 70 ++++++++++++++++++++++++++++++++++++++++++---- fs/btrfs/disk-io.c | 11 ++++++++ 2 files changed, 76 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 3f3a23f52a3b..01310de2bf4a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -13,10 +13,11 @@ extern struct kmem_cache *btrfs_path_cachep; #define BTRFS_MAGIC "_BtRfS_M" #define BTRFS_ROOT_TREE_OBJECTID 1ULL -#define BTRFS_EXTENT_TREE_OBJECTID 2ULL -#define BTRFS_FS_TREE_OBJECTID 3ULL -#define BTRFS_ROOT_TREE_DIR_OBJECTID 4ULL -#define BTRFS_FIRST_FREE_OBJECTID 5ULL +#define BTRFS_DEV_TREE_OBJECTID 2ULL +#define BTRFS_EXTENT_TREE_OBJECTID 3ULL +#define BTRFS_FS_TREE_OBJECTID 4ULL +#define BTRFS_ROOT_TREE_DIR_OBJECTID 5ULL +#define BTRFS_FIRST_FREE_OBJECTID 6ULL /* * we can actually store much bigger names, but lets not confuse the rest @@ -90,6 +91,10 @@ struct btrfs_super_block { __le64 total_blocks; __le64 blocks_used; __le64 root_dir_objectid; + /* fields below here vary with the underlying disk */ + __le64 device_block_start; + __le64 device_num_blocks; + __le64 device_root; } __attribute__ ((__packed__)); /* @@ -223,10 +228,15 @@ struct btrfs_csum_item { u8 csum[BTRFS_CSUM_SIZE]; } __attribute__ ((__packed__)); +struct btrfs_device_item { + __le16 pathlen; +} __attribute__ ((__packed__)); + struct crypto_hash; struct btrfs_fs_info { struct btrfs_root *extent_root; struct btrfs_root *tree_root; + struct btrfs_root *dev_root; struct btrfs_key current_insert; struct btrfs_key last_insert; struct radix_tree_root fs_roots_radix; @@ -312,11 +322,16 @@ struct btrfs_root { */ #define BTRFS_EXTENT_ITEM_KEY 8 +/* + * dev items list the devices that make up the FS + */ +#define BTRFS_DEV_ITEM_KEY 9 + /* * string items are for debugging. They just store a short string of * data in the FS */ -#define BTRFS_STRING_ITEM_KEY 9 +#define BTRFS_STRING_ITEM_KEY 10 static inline u64 btrfs_inode_generation(struct btrfs_inode_item *i) { @@ -782,6 +797,40 @@ static inline void btrfs_set_super_root_dir(struct btrfs_super_block *s, u64 s->root_dir_objectid = cpu_to_le64(val); } +static inline u64 btrfs_super_device_block_start(struct btrfs_super_block *s) +{ + return le64_to_cpu(s->device_block_start); +} + +static inline void btrfs_set_super_device_block_start(struct btrfs_super_block + *s, u64 val) +{ + s->device_block_start = cpu_to_le64(val); +} + +static inline u64 btrfs_super_device_num_blocks(struct btrfs_super_block *s) +{ + return le64_to_cpu(s->device_num_blocks); +} + +static inline void btrfs_set_super_device_num_blocks(struct btrfs_super_block + *s, u64 val) +{ + s->device_num_blocks = cpu_to_le64(val); +} + +static inline u64 btrfs_super_device_root(struct btrfs_super_block *s) +{ + return le64_to_cpu(s->device_root); +} + +static inline void btrfs_set_super_device_root(struct btrfs_super_block + *s, u64 val) +{ + s->device_root = cpu_to_le64(val); +} + + static inline u8 *btrfs_leaf_data(struct btrfs_leaf *l) { return (u8 *)l->items; @@ -849,6 +898,17 @@ static inline void btrfs_set_file_extent_num_blocks(struct e->num_blocks = cpu_to_le64(val); } +static inline u16 btrfs_device_pathlen(struct btrfs_device_item *d) +{ + return le16_to_cpu(d->pathlen); +} + +static inline void btrfs_set_device_pathlen(struct btrfs_device_item *d, + u16 val) +{ + d->pathlen = cpu_to_le16(val); +} + static inline struct btrfs_root *btrfs_sb(struct super_block *sb) { return sb->s_fs_info; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index ff69162829b3..e09233262af6 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -378,6 +378,8 @@ struct btrfs_root *open_ctree(struct super_block *sb) { struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root), GFP_NOFS); + struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root), + GFP_NOFS); struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info), @@ -392,6 +394,7 @@ struct btrfs_root *open_ctree(struct super_block *sb) fs_info->running_transaction = NULL; fs_info->tree_root = tree_root; fs_info->extent_root = extent_root; + fs_info->dev_root = dev_root; fs_info->sb = sb; fs_info->btree_inode = new_inode(sb); fs_info->btree_inode->i_ino = 1; @@ -414,6 +417,9 @@ struct btrfs_root *open_ctree(struct super_block *sb) memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert)); memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert)); + __setup_root(sb->s_blocksize, dev_root, + fs_info, BTRFS_DEV_TREE_OBJECTID); + __setup_root(sb->s_blocksize, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID); fs_info->sb_buffer = read_tree_block(tree_root, @@ -427,6 +433,8 @@ struct btrfs_root *open_ctree(struct super_block *sb) return NULL; fs_info->disk_super = disk_super; + dev_root->node = read_tree_block(tree_root, + btrfs_super_device_root(disk_super)); tree_root->node = read_tree_block(tree_root, btrfs_super_root(disk_super)); BUG_ON(!tree_root->node); @@ -519,6 +527,9 @@ int close_ctree(struct btrfs_root *root) if (fs_info->extent_root->node) btrfs_block_release(fs_info->extent_root, fs_info->extent_root->node); + if (fs_info->dev_root->node) + btrfs_block_release(fs_info->dev_root, + fs_info->dev_root->node); if (fs_info->tree_root->node) btrfs_block_release(fs_info->tree_root, fs_info->tree_root->node);