提交 0bd93ba0 编写于 作者: C Chris Mason 提交者: David Woodhouse

Btrfs: early support for multiple devices

Signed-off-by: NChris Mason <chris.mason@oracle.com>
上级 cac87faa
......@@ -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;
......
......@@ -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);
......
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