From c5739bba5260a59cebd20a51a55080592c8d3b07 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 10 Apr 2007 09:27:04 -0400 Subject: Btrfs: snapshot progress Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 15 +++++- fs/btrfs/dir-item.c | 6 ++- fs/btrfs/disk-io.c | 4 -- fs/btrfs/extent-tree.c | 6 +++ fs/btrfs/ioctl.h | 13 +++++ fs/btrfs/root-tree.c | 16 +++++- fs/btrfs/super.c | 135 +++++++++++++++++++++++++++++++++++++++++++++++-- 7 files changed, 183 insertions(+), 12 deletions(-) create mode 100644 fs/btrfs/ioctl.h diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 5460030c9e6a..2cbcaaeac9e5 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -227,7 +227,7 @@ struct btrfs_csum_item { } __attribute__ ((__packed__)); struct btrfs_inode_map_item { - struct btrfs_disk_key key; + u32 refs; } __attribute__ ((__packed__)); struct crypto_hash; @@ -883,6 +883,17 @@ static inline void btrfs_set_file_extent_num_blocks(struct e->num_blocks = cpu_to_le64(val); } +static inline u32 btrfs_inode_map_refs(struct btrfs_inode_map_item *m) +{ + return le32_to_cpu(m->refs); +} + +static inline void btrfs_set_inode_map_refs(struct btrfs_inode_map_item *m, + u32 val) +{ + m->refs = cpu_to_le32(val); +} + static inline struct btrfs_root *btrfs_sb(struct super_block *sb) { return sb->s_fs_info; @@ -925,6 +936,8 @@ static inline void btrfs_mark_buffer_dirty(struct buffer_head *bh) btrfs_item_offset((leaf)->items + (slot)))) /* extent-item.c */ +int btrfs_inc_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root); struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, struct btrfs_root *root); int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c index 7aed9f015b55..0ba46bc0da9a 100644 --- a/fs/btrfs/dir-item.c +++ b/fs/btrfs/dir-item.c @@ -55,12 +55,14 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root btrfs_set_dir_flags(dir_item, 0); btrfs_set_dir_name_len(dir_item, name_len); name_ptr = (char *)(dir_item + 1); + + btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len); + btrfs_mark_buffer_dirty(path->nodes[0]); + /* FIXME, use some real flag for selecting the extra index */ if (root == root->fs_info->tree_root) goto out; - btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len); - btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(root, path); btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY); diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index b557bdd1e26a..6b097ede80b1 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -16,10 +16,6 @@ static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf) if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) { BUG(); } - if (root->node && btrfs_header_parentid(&node->header) != - btrfs_header_parentid(btrfs_buffer_header(root->node))) { - BUG(); - } return 0; } diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 7c21f63f1b93..efc604eea0b0 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -77,6 +77,12 @@ static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root return 0; } +int btrfs_inc_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + return inc_block_ref(trans, root, root->node->b_blocknr, 1); +} + int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct buffer_head *buf) { diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h new file mode 100644 index 000000000000..201fb3270723 --- /dev/null +++ b/fs/btrfs/ioctl.h @@ -0,0 +1,13 @@ +#ifndef __IOCTL_ +#define __IOCTL_ +#include + +#define BTRFS_IOCTL_MAGIC 0x94 +#define BTRFS_VOL_NAME_MAX 255 +struct btrfs_ioctl_vol_args { + char name[BTRFS_VOL_NAME_MAX + 1]; +}; + +#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \ + struct btrfs_ioctl_vol_args) +#endif diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index ddc1c13a5352..72be9836932f 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -83,6 +83,8 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, { struct btrfs_path *path; int ret; + u32 refs; + struct btrfs_root_item *ri; path = btrfs_alloc_path(); BUG_ON(!path); @@ -91,7 +93,19 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, if (ret < 0) goto out; BUG_ON(ret != 0); - ret = btrfs_del_item(trans, root, path); + ri = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), + path->slots[0], struct btrfs_root_item); + + refs = btrfs_root_refs(ri); + BUG_ON(refs == 0); + if (refs == 1) { + ret = btrfs_del_item(trans, root, path); +printk("deleting root %Lu %Lu %u\n", key->objectid, key->offset, key->flags); + } else { + btrfs_set_root_refs(ri, refs - 1); +printk("ref now %u root %Lu %Lu %u\n", refs -1, key->objectid, key->offset, key->flags); + mark_buffer_dirty(path->nodes[0]); + } out: btrfs_release_path(root, path); btrfs_free_path(path); diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 3c9236ca889c..bbe5cabcb42e 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -15,6 +15,7 @@ #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" +#include "ioctl.h" void btrfs_fsinfo_release(struct kobject *obj) { @@ -27,6 +28,11 @@ struct kobj_type btrfs_fsinfo_ktype = { .release = btrfs_fsinfo_release, }; +struct btrfs_iget_args { + u64 ino; + struct btrfs_root *root; +}; + decl_subsys(btrfs, &btrfs_fsinfo_ktype, NULL); #define BTRFS_SUPER_MAGIC 0x9123682E @@ -461,6 +467,34 @@ int fixup_tree_root_location(struct btrfs_root *root, return 0; } +int btrfs_init_locked_inode(struct inode *inode, void *p) +{ + struct btrfs_iget_args *args = p; + inode->i_ino = args->ino; + BTRFS_I(inode)->root = args->root; + return 0; +} + +int btrfs_find_actor(struct inode *inode, void *opaque) +{ + struct btrfs_iget_args *args = opaque; + return (args->ino == inode->i_ino && + args->root == BTRFS_I(inode)->root); +} + +struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid, + struct btrfs_root *root) +{ + struct inode *inode; + struct btrfs_iget_args args; + args.ino = objectid; + args.root = root; + + inode = iget5_locked(s, objectid, btrfs_find_actor, + btrfs_init_locked_inode, + (void *)&args); + return inode; +} static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) @@ -486,7 +520,8 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, return ERR_PTR(ret); if (ret > 0) return ERR_PTR(-ENOENT); - inode = iget_locked(dir->i_sb, location.objectid); + inode = btrfs_iget_locked(dir->i_sb, location.objectid, + sub_root); if (!inode) return ERR_PTR(-EACCES); if (inode->i_state & I_NEW) { @@ -495,7 +530,7 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, &root->fs_info->fs_roots_radix, (unsigned long)sub_root, sub_root); -printk("adding new root for inode %lu\n", inode->i_ino); +printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_root, BTRFS_I(inode)->root); igrab(inode); sub_root->inode = inode; } @@ -630,7 +665,8 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent) btrfs_super_total_blocks(disk_super), btrfs_super_root_dir(disk_super)); - inode = iget_locked(sb, btrfs_super_root_dir(disk_super)); + inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super), + tree_root); bi = BTRFS_I(inode); bi->location.objectid = inode->i_ino; bi->location.offset = 0; @@ -750,7 +786,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, inode->i_mode = mode; inode->i_ino = objectid; inode->i_blocks = 0; - inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; fill_inode_item(&inode_item, inode); key->objectid = objectid; @@ -1650,6 +1686,95 @@ static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov, return retval; } +static int create_snapshot(struct btrfs_root *root, char *name, int namelen) +{ + struct btrfs_trans_handle *trans; + struct btrfs_key key; + struct btrfs_root_item new_root_item; + int ret; + u64 objectid; + + mutex_lock(&root->fs_info->fs_mutex); + trans = btrfs_start_transaction(root, 1); + BUG_ON(!trans); + + ret = btrfs_update_inode(trans, root, root->inode); + BUG_ON(ret); + + ret = btrfs_find_free_objectid(trans, root, 0, &objectid); + BUG_ON(ret); + + memset(&new_root_item, 0, sizeof(new_root_item)); + memcpy(&new_root_item, &root->root_item, + sizeof(new_root_item)); + + key.objectid = objectid; + key.flags = 0; + key.offset = 0; + btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); + ret = btrfs_insert_inode_map(trans, root, objectid, &key); + BUG_ON(ret); + + key.objectid = objectid; + key.offset = 1; + key.flags = 0; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + btrfs_set_root_blocknr(&new_root_item, root->node->b_blocknr); + + ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, + &new_root_item); + BUG_ON(ret); + +printk("adding snapshot name %.*s root %Lu %Lu %u\n", namelen, name, key.objectid, key.offset, key.flags); + + /* + * insert the directory item + */ + key.offset = (u64)-1; + ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root, + name, namelen, + root->fs_info->sb->s_root->d_inode->i_ino, + &key, 0); + + BUG_ON(ret); + + ret = btrfs_inc_root_ref(trans, root); + BUG_ON(ret); + + ret = btrfs_commit_transaction(trans, root); + BUG_ON(ret); + mutex_unlock(&root->fs_info->fs_mutex); + return 0; +} + +static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int + cmd, unsigned long arg) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_ioctl_vol_args vol_args; + int ret; + int namelen; + + if (!root->ref_cows) + return -EINVAL; + switch (cmd) { + case BTRFS_IOC_SNAP_CREATE: + if (copy_from_user(&vol_args, + (struct btrfs_ioctl_vol_args __user *)arg, + sizeof(vol_args))) + return -EFAULT; + namelen = strlen(vol_args.name); + if (namelen > BTRFS_VOL_NAME_MAX) + return -EINVAL; + ret = create_snapshot(root, vol_args.name, namelen); + WARN_ON(ret); + break; + default: + return -ENOTTY; + } + return 0; +} + static struct kmem_cache *btrfs_inode_cachep; struct kmem_cache *btrfs_trans_handle_cachep; struct kmem_cache *btrfs_transaction_cachep; @@ -1781,6 +1906,7 @@ static struct file_operations btrfs_dir_file_operations = { .llseek = generic_file_llseek, .read = generic_read_dir, .readdir = btrfs_readdir, + .ioctl = btrfs_ioctl, }; static struct address_space_operations btrfs_aops = { @@ -1803,6 +1929,7 @@ static struct file_operations btrfs_file_operations = { .write = btrfs_file_write, .mmap = generic_file_mmap, .open = generic_file_open, + .ioctl = btrfs_ioctl, }; static int __init init_btrfs_fs(void) -- cgit v1.2.3