diff options
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/Makefile | 3 | ||||
| -rw-r--r-- | fs/btrfs/TODO | 1 | ||||
| -rw-r--r-- | fs/btrfs/ctree.h | 123 | ||||
| -rw-r--r-- | fs/btrfs/debug-tree.c | 4 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 135 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.h | 3 | ||||
| -rw-r--r-- | fs/btrfs/extent-tree.c | 15 | ||||
| -rw-r--r-- | fs/btrfs/mkfs.c | 128 | ||||
| -rw-r--r-- | fs/btrfs/print-tree.c | 10 | ||||
| -rw-r--r-- | fs/btrfs/root-tree.c | 88 |
10 files changed, 445 insertions, 65 deletions
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index f853220..13ed631 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -2,7 +2,8 @@ CC=gcc CFLAGS = -g -Wall headers = radix-tree.h ctree.h disk-io.h kerncompat.h print-tree.h list.h -objects = ctree.o disk-io.o radix-tree.o mkfs.o extent-tree.o print-tree.o +objects = ctree.o disk-io.o radix-tree.o mkfs.o extent-tree.o print-tree.o \ + root-tree.o # if you don't have sparse installed, use ls instead CHECKFLAGS=-D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise \ diff --git a/fs/btrfs/TODO b/fs/btrfs/TODO index ad29267..ff90e5e 100644 --- a/fs/btrfs/TODO +++ b/fs/btrfs/TODO @@ -5,6 +5,7 @@ * make a real mkfs and superblock * Do checksumming * Define FS objects in terms of different item types +* add inode tree * Add block mapping tree (simple dm layer) * Add simple tree locking (semaphore per tree) * Make allocator smarter diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 5dfcc90..0968899 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -4,8 +4,13 @@ #include "list.h" #include "kerncompat.h" +#define BTRFS_MAGIC "_BtRfS_M" #define BTRFS_BLOCKSIZE 1024 +#define BTRFS_ROOT_TREE_OBJECTID 1 +#define BTRFS_EXTENT_TREE_OBJECTID 2 +#define BTRFS_FS_TREE_OBJECTID 3 + /* * the key defines the order in the tree, and so it also defines (optimal) * block layout. objectid corresonds to the inode number. The flags @@ -36,7 +41,7 @@ struct btrfs_key { * every tree block (leaf or node) starts with this header. */ struct btrfs_header { - __le64 fsid[2]; /* FS specific uuid */ + u8 fsid[16]; /* FS specific uuid */ __le64 blocknr; /* which block this node is supposed to live in */ __le64 parentid; /* objectid of the tree root */ __le32 csum; @@ -52,6 +57,14 @@ struct btrfs_header { struct btrfs_buffer; +struct btrfs_root_item { + __le64 blocknr; + __le32 flags; + __le64 block_limit; + __le64 blocks_used; + __le32 refs; +}; + /* * in ram representation of the tree. extent_root is used for all allocations * and for the extent tree extent_root root. current_insert is used @@ -61,6 +74,7 @@ struct btrfs_root { struct btrfs_buffer *node; struct btrfs_buffer *commit_root; struct btrfs_root *extent_root; + struct btrfs_root *tree_root; struct btrfs_key current_insert; struct btrfs_key last_insert; int fp; @@ -69,28 +83,25 @@ struct btrfs_root { struct list_head trans; struct list_head cache; int cache_size; + int ref_cows; + struct btrfs_root_item root_item; + struct btrfs_key root_key; }; /* - * describes a tree on disk - */ -struct btrfs_root_info { - u64 fsid[2]; /* FS specific uuid */ - u64 blocknr; /* blocknr of this block */ - u64 objectid; /* inode number of this root */ - u64 tree_root; /* the tree root block */ - u32 csum; - u32 ham; - u64 snapuuid[2]; /* root specific uuid */ -} __attribute__ ((__packed__)); - -/* * the super block basically lists the main trees of the FS * it currently lacks any block count etc etc */ struct btrfs_super_block { - struct btrfs_root_info root_info; - struct btrfs_root_info extent_info; + u8 fsid[16]; /* FS specific uuid */ + __le64 blocknr; /* this block number */ + __le32 csum; + __le64 magic; + __le16 blocksize; + __le64 generation; + __le64 root; + __le64 total_blocks; + __le64 blocks_used; } __attribute__ ((__packed__)); /* @@ -317,6 +328,79 @@ static inline int btrfs_is_leaf(struct btrfs_node *n) return (btrfs_header_level(&n->header) == 0); } +static inline u64 btrfs_root_blocknr(struct btrfs_root_item *item) +{ + return le64_to_cpu(item->blocknr); +} + +static inline void btrfs_set_root_blocknr(struct btrfs_root_item *item, u64 val) +{ + item->blocknr = cpu_to_le64(val); +} + +static inline u32 btrfs_root_refs(struct btrfs_root_item *item) +{ + return le32_to_cpu(item->refs); +} + +static inline void btrfs_set_root_refs(struct btrfs_root_item *item, u32 val) +{ + item->refs = cpu_to_le32(val); +} + +static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s) +{ + return le64_to_cpu(s->blocknr); +} + +static inline void btrfs_set_super_blocknr(struct btrfs_super_block *s, u64 val) +{ + s->blocknr = cpu_to_le64(val); +} + +static inline u64 btrfs_super_root(struct btrfs_super_block *s) +{ + return le64_to_cpu(s->root); +} + +static inline void btrfs_set_super_root(struct btrfs_super_block *s, u64 val) +{ + s->root = cpu_to_le64(val); +} + +static inline u64 btrfs_super_total_blocks(struct btrfs_super_block *s) +{ + return le64_to_cpu(s->total_blocks); +} + +static inline void btrfs_set_super_total_blocks(struct btrfs_super_block *s, + u64 val) +{ + s->total_blocks = cpu_to_le64(val); +} + +static inline u64 btrfs_super_blocks_used(struct btrfs_super_block *s) +{ + return le64_to_cpu(s->blocks_used); +} + +static inline void btrfs_set_super_blocks_used(struct btrfs_super_block *s, + u64 val) +{ + s->blocks_used = cpu_to_le64(val); +} + +static inline u16 btrfs_super_blocksize(struct btrfs_super_block *s) +{ + return le16_to_cpu(s->blocksize); +} + +static inline void btrfs_set_super_blocksize(struct btrfs_super_block *s, + u16 val) +{ + s->blocksize = cpu_to_le16(val); +} + struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root); int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf); int btrfs_free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks); @@ -331,4 +415,11 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path); int btrfs_leaf_free_space(struct btrfs_leaf *leaf); int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap); int btrfs_finish_extent_commit(struct btrfs_root *root); +int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key); +int btrfs_insert_root(struct btrfs_root *root, struct btrfs_key *key, + struct btrfs_root_item *item); +int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key, + struct btrfs_root_item *item); +int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, + struct btrfs_root_item *item, struct btrfs_key *key); #endif diff --git a/fs/btrfs/debug-tree.c b/fs/btrfs/debug-tree.c index 6da0a7a..de45fb4 100644 --- a/fs/btrfs/debug-tree.c +++ b/fs/btrfs/debug-tree.c @@ -11,9 +11,11 @@ int main(int ac, char **av) { struct btrfs_root *root; radix_tree_init(); root = open_ctree("dbfile", &super); - printf("root tree\n"); + printf("fs tree\n"); btrfs_print_tree(root, root->node); printf("map tree\n"); btrfs_print_tree(root->extent_root, root->extent_root->node); + printf("root tree\n"); + btrfs_print_tree(root->tree_root, root->tree_root->node); return 0; } diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index c34c0c6..3d4bf68 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -154,41 +154,96 @@ static int __commit_transaction(struct btrfs_root *root) return ret; } +static int commit_extent_and_tree_roots(struct btrfs_root *tree_root, + struct btrfs_root *extent_root) +{ + int ret; + u64 old_extent_block; + + while(1) { + old_extent_block = btrfs_root_blocknr(&extent_root->root_item); + if (old_extent_block == extent_root->node->blocknr) + break; + btrfs_set_root_blocknr(&extent_root->root_item, + extent_root->node->blocknr); + ret = btrfs_update_root(tree_root, + &extent_root->root_key, + &extent_root->root_item); + BUG_ON(ret); + } + __commit_transaction(extent_root); + __commit_transaction(tree_root); + return 0; +} + int btrfs_commit_transaction(struct btrfs_root *root, struct btrfs_super_block *s) { int ret = 0; + struct btrfs_buffer *snap = root->commit_root; + struct btrfs_key snap_key; ret = __commit_transaction(root); - if (!ret && root != root->extent_root) - ret = __commit_transaction(root->extent_root); BUG_ON(ret); - if (root->commit_root != root->node) { - struct btrfs_buffer *snap = root->commit_root; - root->commit_root = root->node; - root->node->count++; - ret = btrfs_drop_snapshot(root, snap); - BUG_ON(ret); - // btrfs_block_release(root, snap); - } + + if (root->commit_root == root->node) + return 0; + + memcpy(&snap_key, &root->root_key, sizeof(snap_key)); + root->root_key.offset++; + + btrfs_set_root_blocknr(&root->root_item, root->node->blocknr); + ret = btrfs_insert_root(root->tree_root, &root->root_key, + &root->root_item); + BUG_ON(ret); + + ret = commit_extent_and_tree_roots(root->tree_root, root->extent_root); + BUG_ON(ret); + write_ctree_super(root, s); - btrfs_finish_extent_commit(root); + btrfs_finish_extent_commit(root->extent_root); + btrfs_finish_extent_commit(root->tree_root); + + root->commit_root = root->node; + root->node->count++; + ret = btrfs_drop_snapshot(root, snap); + BUG_ON(ret); + + ret = btrfs_del_root(root->tree_root, &snap_key); + BUG_ON(ret); + return ret; } -static int __setup_root(struct btrfs_root *root, struct btrfs_root *extent_root, - struct btrfs_root_info *info, int fp) +static int __setup_root(struct btrfs_root *root, u64 objectid, int fp) { INIT_LIST_HEAD(&root->trans); INIT_LIST_HEAD(&root->cache); root->cache_size = 0; root->fp = fp; root->node = NULL; - root->extent_root = extent_root; root->commit_root = NULL; - root->node = read_tree_block(root, info->tree_root); memset(&root->current_insert, 0, sizeof(root->current_insert)); memset(&root->last_insert, 0, sizeof(root->last_insert)); + memset(&root->root_key, 0, sizeof(root->root_key)); + memset(&root->root_item, 0, sizeof(root->root_item)); + return 0; +} + +static int find_and_setup_root(struct btrfs_root *tree_root, u64 objectid, + struct btrfs_root *root, int fp) +{ + int ret; + + __setup_root(root, objectid, fp); + ret = btrfs_find_last_root(tree_root, objectid, + &root->root_item, &root->root_key); + BUG_ON(ret); + + root->node = read_tree_block(root, + btrfs_root_blocknr(&root->root_item)); + root->ref_cows = 0; + BUG_ON(!root->node); return 0; } @@ -196,9 +251,19 @@ struct btrfs_root *open_ctree(char *filename, struct btrfs_super_block *super) { struct btrfs_root *root = malloc(sizeof(struct btrfs_root)); struct btrfs_root *extent_root = malloc(sizeof(struct btrfs_root)); + struct btrfs_root *tree_root = malloc(sizeof(struct btrfs_root)); int fp; int ret; + root->extent_root = extent_root; + root->tree_root = tree_root; + + extent_root->extent_root = extent_root; + extent_root->tree_root = tree_root; + + tree_root->extent_root = extent_root; + tree_root->tree_root = tree_root; + fp = open(filename, O_CREAT | O_RDWR, 0600); if (fp < 0) { free(root); @@ -208,11 +273,14 @@ struct btrfs_root *open_ctree(char *filename, struct btrfs_super_block *super) INIT_RADIX_TREE(&root->pinned_radix, GFP_KERNEL); INIT_RADIX_TREE(&extent_root->pinned_radix, GFP_KERNEL); INIT_RADIX_TREE(&extent_root->cache_radix, GFP_KERNEL); + INIT_RADIX_TREE(&tree_root->pinned_radix, GFP_KERNEL); + INIT_RADIX_TREE(&tree_root->cache_radix, GFP_KERNEL); + ret = pread(fp, super, sizeof(struct btrfs_super_block), BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE)); - if (ret == 0 || super->root_info.tree_root == 0) { + if (ret == 0 || btrfs_super_root(super) == 0) { printf("making new FS!\n"); - ret = mkfs(fp); + ret = mkfs(fp, 0, BTRFS_BLOCKSIZE); if (ret) return NULL; ret = pread(fp, super, sizeof(struct btrfs_super_block), @@ -221,24 +289,29 @@ struct btrfs_root *open_ctree(char *filename, struct btrfs_super_block *super) return NULL; } BUG_ON(ret < 0); - __setup_root(root, extent_root, &super->root_info, fp); - __setup_root(extent_root, extent_root, &super->extent_info, fp); + + __setup_root(tree_root, BTRFS_ROOT_TREE_OBJECTID, fp); + tree_root->node = read_tree_block(tree_root, btrfs_super_root(super)); + BUG_ON(!tree_root->node); + + ret = find_and_setup_root(tree_root, BTRFS_EXTENT_TREE_OBJECTID, + extent_root, fp); + BUG_ON(ret); + + ret = find_and_setup_root(tree_root, BTRFS_FS_TREE_OBJECTID, + root, fp); + BUG_ON(ret); + root->commit_root = root->node; root->node->count++; + root->ref_cows = 1; return root; } -static int __update_root(struct btrfs_root *root, struct btrfs_root_info *info) -{ - info->tree_root = root->node->blocknr; - return 0; -} - int write_ctree_super(struct btrfs_root *root, struct btrfs_super_block *s) { int ret; - __update_root(root, &s->root_info); - __update_root(root->extent_root, &s->extent_info); + btrfs_set_super_root(s, root->tree_root->node->blocknr); ret = pwrite(root->fp, s, sizeof(*s), BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE)); if (ret != sizeof(*s)) { @@ -260,19 +333,25 @@ static int drop_cache(struct btrfs_root *root) } int close_ctree(struct btrfs_root *root, struct btrfs_super_block *s) { + int ret; btrfs_commit_transaction(root, s); - __commit_transaction(root->extent_root); + ret = commit_extent_and_tree_roots(root->tree_root, root->extent_root); + BUG_ON(ret); write_ctree_super(root, s); drop_cache(root->extent_root); + drop_cache(root->tree_root); drop_cache(root); BUG_ON(!list_empty(&root->trans)); BUG_ON(!list_empty(&root->extent_root->trans)); + BUG_ON(!list_empty(&root->tree_root->trans)); close(root->fp); if (root->node) btrfs_block_release(root, root->node); if (root->extent_root->node) btrfs_block_release(root->extent_root, root->extent_root->node); + if (root->tree_root->node) + btrfs_block_release(root->tree_root, root->tree_root->node); btrfs_block_release(root, root->commit_root); free(root); printf("on close %d blocks are allocated\n", allocated_blocks); diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index b391335..c22a61f 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -24,7 +24,8 @@ struct btrfs_root *open_ctree(char *filename, struct btrfs_super_block *s); int close_ctree(struct btrfs_root *root, struct btrfs_super_block *s); void btrfs_block_release(struct btrfs_root *root, struct btrfs_buffer *buf); int write_ctree_super(struct btrfs_root *root, struct btrfs_super_block *s); -int mkfs(int fd); +int mkfs(int fd, u64 num_blocks, u16 blocksize); + #define BTRFS_SUPER_INFO_OFFSET(bs) (16 * (bs)) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a696953..21f39b40 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -82,7 +82,7 @@ int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf) u64 blocknr; int i; - if (root == root->extent_root) + if (!root->ref_cows) return 0; if (btrfs_is_leaf(&buf->node)) return 0; @@ -96,23 +96,22 @@ int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf) int btrfs_finish_extent_commit(struct btrfs_root *root) { - struct btrfs_root *extent_root = root->extent_root; unsigned long gang[8]; int ret; int i; while(1) { - ret = radix_tree_gang_lookup(&extent_root->pinned_radix, + ret = radix_tree_gang_lookup(&root->pinned_radix, (void **)gang, 0, ARRAY_SIZE(gang)); if (!ret) break; for (i = 0; i < ret; i++) { - radix_tree_delete(&extent_root->pinned_radix, gang[i]); + radix_tree_delete(&root->pinned_radix, gang[i]); } } - extent_root->last_insert.objectid = 0; - extent_root->last_insert.offset = 0; + root->last_insert.objectid = 0; + root->last_insert.offset = 0; return 0; } @@ -173,7 +172,7 @@ static int __free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks) refs = btrfs_extent_refs(ei) - 1; btrfs_set_extent_refs(ei, refs); if (refs == 0) { - if (root == extent_root) { + if (!root->ref_cows) { int err; radix_tree_preload(GFP_KERNEL); err = radix_tree_insert(&extent_root->pinned_radix, @@ -513,7 +512,7 @@ static int walk_up_tree(struct btrfs_root *root, struct btrfs_path *path, */ int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap) { - int ret = 0;; + int ret = 0; int wret; int level; struct btrfs_path path; diff --git a/fs/btrfs/mkfs.c b/fs/btrfs/mkfs.c index fc19233..dd14ed4 100644 --- a/fs/btrfs/mkfs.c +++ b/fs/btrfs/mkfs.c @@ -10,6 +10,120 @@ #include "ctree.h" #include "disk-io.h" +int mkfs(int fd, u64 num_blocks, u16 blocksize) +{ + struct btrfs_super_block super; + struct btrfs_leaf empty_leaf; + struct btrfs_root_item root_item; + struct btrfs_item item; + struct btrfs_extent_item extent_item; + char *block; + int ret; + u16 itemoff; + + btrfs_set_super_blocknr(&super, 16); + btrfs_set_super_root(&super, 17); + strcpy((char *)(&super.magic), BTRFS_MAGIC); + btrfs_set_super_blocksize(&super, blocksize); + btrfs_set_super_total_blocks(&super, num_blocks); + btrfs_set_super_blocks_used(&super, 0); + + block = malloc(blocksize); + memset(block, 0, blocksize); + BUG_ON(sizeof(super) > blocksize); + memcpy(block, &super, sizeof(super)); + ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET(blocksize)); + BUG_ON(ret != blocksize); + + /* create the tree of root objects */ + memset(&empty_leaf, 0, sizeof(empty_leaf)); + btrfs_set_header_parentid(&empty_leaf.header, BTRFS_ROOT_TREE_OBJECTID); + btrfs_set_header_blocknr(&empty_leaf.header, 17); + btrfs_set_header_nritems(&empty_leaf.header, 2); + + /* create the items for the root tree */ + btrfs_set_root_blocknr(&root_item, 18); + btrfs_set_root_refs(&root_item, 1); + itemoff = LEAF_DATA_SIZE - sizeof(root_item); + btrfs_set_item_offset(&item, itemoff); + btrfs_set_item_size(&item, sizeof(root_item)); + btrfs_set_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID); + btrfs_set_key_offset(&item.key, 0); + btrfs_set_key_flags(&item.key, 0); + memcpy(empty_leaf.items, &item, sizeof(item)); + memcpy(empty_leaf.data + itemoff, &root_item, sizeof(root_item)); + + btrfs_set_root_blocknr(&root_item, 19); + itemoff = itemoff - sizeof(root_item); + btrfs_set_item_offset(&item, itemoff); + btrfs_set_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID); + memcpy(empty_leaf.items + 1, &item, sizeof(item)); + memcpy(empty_leaf.data + itemoff, &root_item, sizeof(root_item)); + ret = pwrite(fd, &empty_leaf, blocksize, 17 * blocksize); + + /* create the items for the extent tree */ + btrfs_set_header_parentid(&empty_leaf.header, + BTRFS_EXTENT_TREE_OBJECTID); + btrfs_set_header_blocknr(&empty_leaf.header, 18); + btrfs_set_header_nritems(&empty_leaf.header, 4); + + /* item1, reserve blocks 0-16 */ + btrfs_set_key_objectid(&item.key, 0); + btrfs_set_key_offset(&item.key, 17); + btrfs_set_key_flags(&item.key, 0); + itemoff = LEAF_DATA_SIZE - sizeof(struct btrfs_extent_item); + btrfs_set_item_offset(&item, itemoff); + btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item)); + btrfs_set_extent_refs(&extent_item, 1); + btrfs_set_extent_owner(&extent_item, 0); + memcpy(empty_leaf.items, &item, sizeof(item)); + memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item, + btrfs_item_size(&item)); + + /* item2, give block 17 to the root */ + btrfs_set_key_objectid(&item.key, 17); + btrfs_set_key_offset(&item.key, 1); + itemoff = itemoff - sizeof(struct btrfs_extent_item); + btrfs_set_item_offset(&item, itemoff); + btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID); + memcpy(empty_leaf.items + 1, &item, sizeof(item)); + memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item, + btrfs_item_size(&item)); + + /* item3, give block 18 to the extent root */ + btrfs_set_key_objectid(&item.key, 18); + btrfs_set_key_offset(&item.key, 1); + itemoff = itemoff - sizeof(struct btrfs_extent_item); + btrfs_set_item_offset(&item, itemoff); + btrfs_set_extent_owner(&extent_item, BTRFS_EXTENT_TREE_OBJECTID); + memcpy(empty_leaf.items + 2, &item, sizeof(item)); + memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item, + btrfs_item_size(&item)); + + /* item4, give block 19 to the FS root */ + btrfs_set_key_objectid(&item.key, 19); + btrfs_set_key_offset(&item.key, 1); + itemoff = itemoff - sizeof(struct btrfs_extent_item); + btrfs_set_item_offset(&item, itemoff); + btrfs_set_extent_owner(&extent_item, BTRFS_FS_TREE_OBJECTID); + memcpy(empty_leaf.items + 3, &item, sizeof(item)); + memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item, + btrfs_item_size(&item)); + ret = pwrite(fd, &empty_leaf, blocksize, 18 * blocksize); + if (ret != sizeof(empty_leaf)) + return -1; + + /* finally create the FS root */ + btrfs_set_header_parentid(&empty_leaf.header, BTRFS_FS_TREE_OBJECTID); + btrfs_set_header_blocknr(&empty_leaf.header, 19); + btrfs_set_header_nritems(&empty_leaf.header, 0); + ret = pwrite(fd, &empty_leaf, blocksize, 19 * blocksize); + if (ret != sizeof(empty_leaf)) + return -1; + return 0; +} + +#if 0 int mkfs(int fd) { struct btrfs_root_info info[2]; @@ -20,13 +134,14 @@ int mkfs(int fd) /* setup the super block area */ memset(info, 0, sizeof(info)); - info[0].blocknr = 16; - info[0].objectid = 1; - info[0].tree_root = 17; + btrfs_set_root_blocknr(info, 16); + btrfs_set_root_objectid(info, 1); + btrfs_set_root_tree_root(info, 17); + + btrfs_set_root_blocknr(info + 1, 16); + btrfs_set_root_objectid(info + 1, 2); + btrfs_set_root_tree_root(info + 1, 18); - info[1].blocknr = 16; - info[1].objectid = 2; - info[1].tree_root = 18; ret = pwrite(fd, info, sizeof(info), BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE)); if (ret != sizeof(info)) @@ -81,3 +196,4 @@ int mkfs(int fd) return -1; return 0; } +#endif diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c index c95c856..64829b6 100644 --- a/fs/btrfs/print-tree.c +++ b/fs/btrfs/print-tree.c @@ -11,6 +11,7 @@ void btrfs_print_leaf(struct btrfs_leaf *l) u32 nr = btrfs_header_nritems(&l->header); struct btrfs_item *item; struct btrfs_extent_item *ei; + struct btrfs_root_item *ri; printf("leaf %Lu total ptrs %d free space %d\n", btrfs_header_blocknr(&l->header), nr, btrfs_leaf_free_space(l)); fflush(stdout); @@ -23,13 +24,15 @@ void btrfs_print_leaf(struct btrfs_leaf *l) btrfs_key_offset(&item->key), btrfs_item_offset(item), btrfs_item_size(item)); - fflush(stdout); printf("\t\titem data %.*s\n", btrfs_item_size(item), l->data + btrfs_item_offset(item)); ei = (struct btrfs_extent_item *)(l->data + btrfs_item_offset(item)); - printf("\t\textent data refs %u owner %Lu\n", ei->refs, - ei->owner); + printf("\t\textent data refs %u owner %Lu\n", + btrfs_extent_refs(ei), btrfs_extent_owner(ei)); + ri = (struct btrfs_root_item *)ei; + printf("\t\troot data blocknr %Lu refs %u\n", + btrfs_root_blocknr(ri), btrfs_root_refs(ri)); fflush(stdout); } } @@ -71,6 +74,5 @@ void btrfs_print_tree(struct btrfs_root *root, struct btrfs_buffer *t) btrfs_print_tree(root, next_buf); btrfs_block_release(root, next_buf); } - } diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c new file mode 100644 index 0000000..0ab90cf --- /dev/null +++ b/fs/btrfs/root-tree.c @@ -0,0 +1,88 @@ +#include <stdio.h> +#include <stdlib.h> +#include "kerncompat.h" +#include "radix-tree.h" +#include "ctree.h" +#include "disk-io.h" +#include "print-tree.h" + +int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, + struct btrfs_root_item *item, struct btrfs_key *key) +{ + struct btrfs_path path; + struct btrfs_key search_key; + struct btrfs_leaf *l; + int ret; + int slot; + + search_key.objectid = objectid; + search_key.flags = (u32)-1; + search_key.offset = (u32)-1; + + btrfs_init_path(&path); + ret = btrfs_search_slot(root, &search_key, &path, 0, 0); + if (ret < 0) + goto out; + BUG_ON(ret == 0); + l = &path.nodes[0]->leaf; + BUG_ON(path.slots[0] == 0); + slot = path.slots[0] - 1; + if (btrfs_key_objectid(&l->items[slot].key) != objectid) { + ret = 1; + goto out; + } + memcpy(item, l->data + btrfs_item_offset(l->items + slot), + sizeof(*item)); + btrfs_disk_key_to_cpu(key, &l->items[slot].key); + btrfs_release_path(root, &path); + ret = 0; +out: + return ret; +} + +int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key, + struct btrfs_root_item *item) +{ + struct btrfs_path path; + struct btrfs_leaf *l; + int ret; + int slot; + + btrfs_init_path(&path); + ret = btrfs_search_slot(root, key, &path, 0, 1); + if (ret < 0) + goto out; + BUG_ON(ret != 0); + l = &path.nodes[0]->leaf; + slot = path.slots[0]; + memcpy(l->data + btrfs_item_offset(l->items + slot), item, + sizeof(*item)); +out: + btrfs_release_path(root, &path); + return ret; +} + +int btrfs_insert_root(struct btrfs_root *root, struct btrfs_key *key, + struct btrfs_root_item *item) +{ + int ret; + ret = btrfs_insert_item(root, key, item, sizeof(*item)); + BUG_ON(ret); + return ret; +} + +int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key) +{ + struct btrfs_path path; + int ret; + + btrfs_init_path(&path); + ret = btrfs_search_slot(root, key, &path, -1, 1); + if (ret < 0) + goto out; + BUG_ON(ret != 0); + ret = btrfs_del_item(root, &path); +out: + btrfs_release_path(root, &path); + return ret; +} |
