X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=fs%2Fbtrfs%2Fioctl.c;h=e8795becad4cda9ce6e97ce87c77edc62f73c9a0;hb=efefb1438be269897585934fc6c05deb4dfa01ce;hp=9f4db848db10dcb24c40ebe2529b3ff609c9cc1b;hpb=39bd8064ab3648bc38b1a3ef507031ee6a477966;p=~andy%2Flinux diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 9f4db848db1..e8795becad4 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -27,7 +27,6 @@ #include #include #include -#include #include #include #include @@ -231,8 +230,8 @@ static noinline int create_subvol(struct btrfs_root *root, struct btrfs_root_item root_item; struct btrfs_inode_item *inode_item; struct extent_buffer *leaf; - struct btrfs_root *new_root = root; - struct inode *dir; + struct btrfs_root *new_root; + struct inode *dir = dentry->d_parent->d_inode; int ret; int err; u64 objectid; @@ -240,9 +239,15 @@ static noinline int create_subvol(struct btrfs_root *root, u64 index = 0; unsigned long nr = 1; - ret = btrfs_check_metadata_free_space(root); + /* + * 1 - inode item + * 2 - refs + * 1 - root item + * 2 - dir items + */ + ret = btrfs_reserve_metadata_space(root, 6); if (ret) - goto fail_commit; + return ret; trans = btrfs_start_transaction(root, 1); BUG_ON(!trans); @@ -305,11 +310,17 @@ static noinline int create_subvol(struct btrfs_root *root, if (ret) goto fail; + key.offset = (u64)-1; + new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); + BUG_ON(IS_ERR(new_root)); + + btrfs_record_root_in_trans(trans, new_root); + + ret = btrfs_create_subvol_root(trans, new_root, new_dirid, + BTRFS_I(dir)->block_group); /* * insert the directory item */ - key.offset = (u64)-1; - dir = dentry->d_parent->d_inode; ret = btrfs_set_inode_index(dir, &index); BUG_ON(ret); @@ -323,43 +334,20 @@ static noinline int create_subvol(struct btrfs_root *root, ret = btrfs_update_inode(trans, root, dir); BUG_ON(ret); - /* add the backref first */ ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, - objectid, BTRFS_ROOT_BACKREF_KEY, - root->root_key.objectid, + objectid, root->root_key.objectid, dir->i_ino, index, name, namelen); BUG_ON(ret); - /* now add the forward ref */ - ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, - root->root_key.objectid, BTRFS_ROOT_REF_KEY, - objectid, - dir->i_ino, index, name, namelen); - - BUG_ON(ret); - - ret = btrfs_commit_transaction(trans, root); - if (ret) - goto fail_commit; - - new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); - BUG_ON(!new_root); - - trans = btrfs_start_transaction(new_root, 1); - BUG_ON(!trans); - - ret = btrfs_create_subvol_root(trans, new_root, dentry, new_dirid, - BTRFS_I(dir)->block_group); - if (ret) - goto fail; - + d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); fail: nr = trans->blocks_used; - err = btrfs_commit_transaction(trans, new_root); + err = btrfs_commit_transaction(trans, root); if (err && !ret) ret = err; -fail_commit: + + btrfs_unreserve_metadata_space(root, 6); btrfs_btree_balance_dirty(root, nr); return ret; } @@ -376,19 +364,27 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, if (!root->ref_cows) return -EINVAL; - ret = btrfs_check_metadata_free_space(root); + /* + * 1 - inode item + * 2 - refs + * 1 - root item + * 2 - dir items + */ + ret = btrfs_reserve_metadata_space(root, 6); if (ret) goto fail_unlock; pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS); if (!pending_snapshot) { ret = -ENOMEM; + btrfs_unreserve_metadata_space(root, 6); goto fail_unlock; } pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS); if (!pending_snapshot->name) { ret = -ENOMEM; kfree(pending_snapshot); + btrfs_unreserve_metadata_space(root, 6); goto fail_unlock; } memcpy(pending_snapshot->name, name, namelen); @@ -421,14 +417,15 @@ static inline int btrfs_may_create(struct inode *dir, struct dentry *child) * sys_mkdirat and vfs_mkdir, but we only do a single component lookup * inside this filesystem so it's quite a bit simpler. */ -static noinline int btrfs_mksubvol(struct path *parent, char *name, - int mode, int namelen, +static noinline int btrfs_mksubvol(struct path *parent, + char *name, int namelen, struct btrfs_root *snap_src) { + struct inode *dir = parent->dentry->d_inode; struct dentry *dentry; int error; - mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); dentry = lookup_one_len(name, parent->dentry, namelen); error = PTR_ERR(dentry); @@ -439,99 +436,39 @@ static noinline int btrfs_mksubvol(struct path *parent, char *name, if (dentry->d_inode) goto out_dput; - if (!IS_POSIXACL(parent->dentry->d_inode)) - mode &= ~current_umask(); - error = mnt_want_write(parent->mnt); if (error) goto out_dput; - error = btrfs_may_create(parent->dentry->d_inode, dentry); + error = btrfs_may_create(dir, dentry); if (error) goto out_drop_write; - /* - * Actually perform the low-level subvolume creation after all - * this VFS fuzz. - * - * Eventually we want to pass in an inode under which we create this - * subvolume, but for now all are under the filesystem root. - * - * Also we should pass on the mode eventually to allow creating new - * subvolume with specific mode bits. - */ + down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); + + if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0) + goto out_up_read; + if (snap_src) { - struct dentry *dir = dentry->d_parent; - struct dentry *test = dir->d_parent; - struct btrfs_path *path = btrfs_alloc_path(); - int ret; - u64 test_oid; - u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid; - - test_oid = snap_src->root_key.objectid; - - ret = btrfs_find_root_ref(snap_src->fs_info->tree_root, - path, parent_oid, test_oid); - if (ret == 0) - goto create; - btrfs_release_path(snap_src->fs_info->tree_root, path); - - /* we need to make sure we aren't creating a directory loop - * by taking a snapshot of something that has our current - * subvol in its directory tree. So, this loops through - * the dentries and checks the forward refs for each subvolume - * to see if is references the subvolume where we are - * placing this new snapshot. - */ - while (1) { - if (!test || - dir == snap_src->fs_info->sb->s_root || - test == snap_src->fs_info->sb->s_root || - test->d_inode->i_sb != snap_src->fs_info->sb) { - break; - } - if (S_ISLNK(test->d_inode->i_mode)) { - printk(KERN_INFO "Btrfs symlink in snapshot " - "path, failed\n"); - error = -EMLINK; - btrfs_free_path(path); - goto out_drop_write; - } - test_oid = - BTRFS_I(test->d_inode)->root->root_key.objectid; - ret = btrfs_find_root_ref(snap_src->fs_info->tree_root, - path, test_oid, parent_oid); - if (ret == 0) { - printk(KERN_INFO "Btrfs snapshot creation " - "failed, looping\n"); - error = -EMLINK; - btrfs_free_path(path); - goto out_drop_write; - } - btrfs_release_path(snap_src->fs_info->tree_root, path); - test = test->d_parent; - } -create: - btrfs_free_path(path); - error = create_snapshot(snap_src, dentry, name, namelen); + error = create_snapshot(snap_src, dentry, + name, namelen); } else { - error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root, - dentry, name, namelen); + error = create_subvol(BTRFS_I(dir)->root, dentry, + name, namelen); } - if (error) - goto out_drop_write; - - fsnotify_mkdir(parent->dentry->d_inode, dentry); + if (!error) + fsnotify_mkdir(dir, dentry); +out_up_read: + up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); out_drop_write: mnt_drop_write(parent->mnt); out_dput: dput(dentry); out_unlock: - mutex_unlock(&parent->dentry->d_inode->i_mutex); + mutex_unlock(&dir->i_mutex); return error; } - static int btrfs_defrag_file(struct file *file) { struct inode *inode = fdentry(file)->d_inode; @@ -597,9 +534,8 @@ again: clear_page_dirty_for_io(page); btrfs_set_extent_delalloc(inode, page_start, page_end); - - unlock_extent(io_tree, page_start, page_end, GFP_NOFS); set_page_dirty(page); + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); unlock_page(page); page_cache_release(page); balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1); @@ -610,7 +546,8 @@ out_unlock: return 0; } -static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) +static noinline int btrfs_ioctl_resize(struct btrfs_root *root, + void __user *arg) { u64 new_size; u64 old_size; @@ -719,10 +656,7 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, { struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; struct btrfs_ioctl_vol_args *vol_args; - struct btrfs_dir_item *di; - struct btrfs_path *path; struct file *src_file; - u64 root_dirid; int namelen; int ret = 0; @@ -740,32 +674,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, goto out; } - path = btrfs_alloc_path(); - if (!path) { - ret = -ENOMEM; - goto out; - } - - root_dirid = root->fs_info->sb->s_root->d_inode->i_ino, - di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, - path, root_dirid, - vol_args->name, namelen, 0); - btrfs_free_path(path); - - if (di && !IS_ERR(di)) { - ret = -EEXIST; - goto out; - } - - if (IS_ERR(di)) { - ret = PTR_ERR(di); - goto out; - } - if (subvol) { - ret = btrfs_mksubvol(&file->f_path, vol_args->name, - file->f_path.dentry->d_inode->i_mode, - namelen, NULL); + ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen, + NULL); } else { struct inode *src_inode; src_file = fget(vol_args->fd); @@ -782,17 +693,157 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, fput(src_file); goto out; } - ret = btrfs_mksubvol(&file->f_path, vol_args->name, - file->f_path.dentry->d_inode->i_mode, - namelen, BTRFS_I(src_inode)->root); + ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen, + BTRFS_I(src_inode)->root); fput(src_file); } - out: kfree(vol_args); return ret; } +/* + * helper to check if the subvolume references other subvolumes + */ +static noinline int may_destroy_subvol(struct btrfs_root *root) +{ + struct btrfs_path *path; + struct btrfs_key key; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = root->root_key.objectid; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, root->fs_info->tree_root, + &key, path, 0, 0); + if (ret < 0) + goto out; + BUG_ON(ret == 0); + + ret = 0; + if (path->slots[0] > 0) { + path->slots[0]--; + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.objectid == root->root_key.objectid && + key.type == BTRFS_ROOT_REF_KEY) + ret = -ENOTEMPTY; + } +out: + btrfs_free_path(path); + return ret; +} + +static noinline int btrfs_ioctl_snap_destroy(struct file *file, + void __user *arg) +{ + struct dentry *parent = fdentry(file); + struct dentry *dentry; + struct inode *dir = parent->d_inode; + struct inode *inode; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_root *dest = NULL; + struct btrfs_ioctl_vol_args *vol_args; + struct btrfs_trans_handle *trans; + int namelen; + int ret; + int err = 0; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + vol_args = memdup_user(arg, sizeof(*vol_args)); + if (IS_ERR(vol_args)) + return PTR_ERR(vol_args); + + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; + namelen = strlen(vol_args->name); + if (strchr(vol_args->name, '/') || + strncmp(vol_args->name, "..", namelen) == 0) { + err = -EINVAL; + goto out; + } + + err = mnt_want_write(file->f_path.mnt); + if (err) + goto out; + + mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); + dentry = lookup_one_len(vol_args->name, parent, namelen); + if (IS_ERR(dentry)) { + err = PTR_ERR(dentry); + goto out_unlock_dir; + } + + if (!dentry->d_inode) { + err = -ENOENT; + goto out_dput; + } + + inode = dentry->d_inode; + if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) { + err = -EINVAL; + goto out_dput; + } + + dest = BTRFS_I(inode)->root; + + mutex_lock(&inode->i_mutex); + err = d_invalidate(dentry); + if (err) + goto out_unlock; + + down_write(&root->fs_info->subvol_sem); + + err = may_destroy_subvol(dest); + if (err) + goto out_up_write; + + trans = btrfs_start_transaction(root, 1); + ret = btrfs_unlink_subvol(trans, root, dir, + dest->root_key.objectid, + dentry->d_name.name, + dentry->d_name.len); + BUG_ON(ret); + + btrfs_record_root_in_trans(trans, dest); + + memset(&dest->root_item.drop_progress, 0, + sizeof(dest->root_item.drop_progress)); + dest->root_item.drop_level = 0; + btrfs_set_root_refs(&dest->root_item, 0); + + ret = btrfs_insert_orphan_item(trans, + root->fs_info->tree_root, + dest->root_key.objectid); + BUG_ON(ret); + + ret = btrfs_commit_transaction(trans, root); + BUG_ON(ret); + inode->i_flags |= S_DEAD; +out_up_write: + up_write(&root->fs_info->subvol_sem); +out_unlock: + mutex_unlock(&inode->i_mutex); + if (!err) { + shrink_dcache_sb(root->fs_info->sb); + btrfs_invalidate_inodes(dest); + d_delete(dentry); + } +out_dput: + dput(dentry); +out_unlock_dir: + mutex_unlock(&dir->i_mutex); + mnt_drop_write(file->f_path.mnt); +out: + kfree(vol_args); + return err; +} + static int btrfs_ioctl_defrag(struct file *file) { struct inode *inode = fdentry(file)->d_inode; @@ -866,8 +917,8 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) return ret; } -static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, - u64 off, u64 olen, u64 destoff) +static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, + u64 off, u64 olen, u64 destoff) { struct inode *inode = fdentry(file)->d_inode; struct btrfs_root *root = BTRFS_I(inode)->root; @@ -977,7 +1028,7 @@ static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, /* punch hole in destination first */ btrfs_drop_extents(trans, root, inode, off, off + len, - off + len, 0, &hint_byte); + off + len, 0, &hint_byte, 1); /* clone data */ key.objectid = src->i_ino; @@ -1072,8 +1123,7 @@ static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, datao += off - key.offset; datal -= off - key.offset; } - if (key.offset + datao + datal + key.offset > - off + len) + if (key.offset + datao + datal > off + len) datal = off + len - key.offset - datao; /* disko == 0 means it's a hole */ if (!disko) @@ -1183,15 +1233,15 @@ static long btrfs_ioctl_trans_start(struct file *file) struct inode *inode = fdentry(file)->d_inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; - int ret = 0; + int ret; + ret = -EPERM; if (!capable(CAP_SYS_ADMIN)) - return -EPERM; + goto out; - if (file->private_data) { - ret = -EINPROGRESS; + ret = -EINPROGRESS; + if (file->private_data) goto out; - } ret = mnt_want_write(file->f_path.mnt); if (ret) @@ -1201,12 +1251,19 @@ static long btrfs_ioctl_trans_start(struct file *file) root->fs_info->open_ioctl_trans++; mutex_unlock(&root->fs_info->trans_mutex); + ret = -ENOMEM; trans = btrfs_start_ioctl_transaction(root, 0); - if (trans) - file->private_data = trans; - else - ret = -ENOMEM; - /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/ + if (!trans) + goto out_drop; + + file->private_data = trans; + return 0; + +out_drop: + mutex_lock(&root->fs_info->trans_mutex); + root->fs_info->open_ioctl_trans--; + mutex_unlock(&root->fs_info->trans_mutex); + mnt_drop_write(file->f_path.mnt); out: return ret; } @@ -1222,24 +1279,20 @@ long btrfs_ioctl_trans_end(struct file *file) struct inode *inode = fdentry(file)->d_inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; - int ret = 0; trans = file->private_data; - if (!trans) { - ret = -EINVAL; - goto out; - } - btrfs_end_transaction(trans, root); + if (!trans) + return -EINVAL; file->private_data = NULL; + btrfs_end_transaction(trans, root); + mutex_lock(&root->fs_info->trans_mutex); root->fs_info->open_ioctl_trans--; mutex_unlock(&root->fs_info->trans_mutex); mnt_drop_write(file->f_path.mnt); - -out: - return ret; + return 0; } long btrfs_ioctl(struct file *file, unsigned int @@ -1259,6 +1312,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_snap_create(file, argp, 0); case BTRFS_IOC_SUBVOL_CREATE: return btrfs_ioctl_snap_create(file, argp, 1); + case BTRFS_IOC_SNAP_DESTROY: + return btrfs_ioctl_snap_destroy(file, argp); case BTRFS_IOC_DEFRAG: return btrfs_ioctl_defrag(file); case BTRFS_IOC_RESIZE: