/* * Copyright (C) 2014 Fujitsu. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ /* * Unlike inode.c in kernel, which can use most of the kernel infrastructure * like inode/dentry things, in user-land, we can only use inode number to * do directly operation on extent buffer, which may cause extra searching, * but should not be a huge problem since progs is less performance sensitive. */ #include #include "ctree.h" #include "transaction.h" #include "disk-io.h" #include "time.h" #include "common/messages.h" #include "common/internal.h" /* * Find a free inode index for later btrfs_add_link(). * Currently just search from the largest dir_index and +1. */ static int btrfs_find_free_dir_index(struct btrfs_root *root, u64 dir_ino, u64 *ret_ino) { struct btrfs_path *path; struct btrfs_key key; struct btrfs_key found_key; u64 ret_val = 2; int ret = 0; if (!ret_ino) return 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = dir_ino; key.type = BTRFS_DIR_INDEX_KEY; key.offset = (u64)-1; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; ret = 0; if (path->slots[0] == 0) { ret = btrfs_prev_leaf(root, path); if (ret < 0) goto out; if (ret > 0) { /* * This shouldn't happen since there must be a leaf * containing the DIR_ITEM. * Can only happen when the previous leaf is corrupted. */ ret = -EIO; goto out; } } else { path->slots[0]--; } btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); if (found_key.objectid != dir_ino || found_key.type != BTRFS_DIR_INDEX_KEY) goto out; ret_val = found_key.offset + 1; out: btrfs_free_path(path); if (ret == 0) *ret_ino = ret_val; return ret; } /* Check the dir_item/index conflicts before insert */ int check_dir_conflict(struct btrfs_root *root, char *name, int namelen, u64 dir, u64 index) { struct btrfs_path *path; struct btrfs_key key; struct btrfs_inode_item *inode_item; struct btrfs_dir_item *dir_item; int ret = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; /* Given dir exists? */ key.objectid = dir; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; if (ret > 0) { ret = -ENOENT; goto out; } /* Is it a dir? */ inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); if (!(btrfs_inode_mode(path->nodes[0], inode_item) & S_IFDIR)) { ret = -ENOTDIR; goto out; } btrfs_release_path(path); /* Name conflicting? */ dir_item = btrfs_lookup_dir_item(NULL, root, path, dir, name, namelen, 0); if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } if (dir_item) { ret = -EEXIST; goto out; } btrfs_release_path(path); /* Index conflicting? */ dir_item = btrfs_lookup_dir_index(NULL, root, path, dir, name, namelen, index, 0); if (IS_ERR(dir_item) && PTR_ERR(dir_item) == -ENOENT) dir_item = NULL; if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } if (dir_item) { ret = -EEXIST; goto out; } out: btrfs_free_path(path); return ret; } /* * Add dir_item/index for 'parent_ino' if add_backref is true, also insert a * backref from the ino to parent dir and update the nlink(Kernel version does * not do this thing) * * Currently only supports adding link from an inode to another inode. */ int btrfs_add_link(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 ino, u64 parent_ino, char *name, int namelen, u8 type, u64 *index, int add_backref, int ignore_existed) { struct btrfs_path *path; struct btrfs_key key; struct btrfs_inode_item *inode_item; u32 nlink; u64 inode_size; u64 ret_index = 0; int ret = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; if (index && *index) { ret_index = *index; } else { ret = btrfs_find_free_dir_index(root, parent_ino, &ret_index); if (ret < 0) goto out; } ret = check_dir_conflict(root, name, namelen, parent_ino, ret_index); if (ret < 0 && !(ignore_existed && ret == -EEXIST)) goto out; /* Add inode ref */ if (add_backref) { ret = btrfs_insert_inode_ref(trans, root, name, namelen, ino, parent_ino, ret_index); if (ret < 0 && !(ignore_existed && ret == -EEXIST)) goto out; /* do not update nlinks if existed */ if (!ret) { /* Update nlinks for the inode */ key.objectid = ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(trans, root, &key, path, 1, 1); if (ret) { if (ret > 0) ret = -ENOENT; goto out; } inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); nlink = btrfs_inode_nlink(path->nodes[0], inode_item); nlink++; btrfs_set_inode_nlink(path->nodes[0], inode_item, nlink); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(path); } } /* Add dir_item and dir_index */ key.objectid = ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_insert_dir_item(trans, root, name, namelen, parent_ino, &key, type, ret_index); if (ret < 0) goto out; /* Update inode size of the parent inode */ key.objectid = parent_ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(trans, root, &key, path, 1, 1); if (ret) goto out; inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); inode_size = btrfs_inode_size(path->nodes[0], inode_item); inode_size += namelen * 2; btrfs_set_inode_size(path->nodes[0], inode_item, inode_size); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(path); out: btrfs_free_path(path); if (ret == 0 && index) *index = ret_index; return ret; } int btrfs_add_orphan_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 ino) { struct btrfs_key key; key.objectid = BTRFS_ORPHAN_OBJECTID; key.type = BTRFS_ORPHAN_ITEM_KEY; key.offset = ino; return btrfs_insert_empty_item(trans, root, path, &key, 0); } /* * Unlink an inode, which will remove its backref and corresponding dir_index/ * dir_item if any of them exists. * * If an inode's nlink is reduced to 0 and 'add_orphan' is true, it will be * added to orphan inode and waiting to be deleted by next kernel mount. */ int btrfs_unlink(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 ino, u64 parent_ino, u64 index, const char *name, int namelen, int add_orphan) { struct btrfs_path *path; struct btrfs_key key; struct btrfs_inode_item *inode_item; struct btrfs_inode_ref *inode_ref; struct btrfs_dir_item *dir_item; u64 inode_size; u32 nlinks; int del_inode_ref = 0; int del_dir_item = 0; int del_dir_index = 0; int ret = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; /* check the ref and backref exists */ inode_ref = btrfs_lookup_inode_ref(trans, root, path, name, namelen, ino, parent_ino, 0); if (IS_ERR(inode_ref)) { ret = PTR_ERR(inode_ref); goto out; } if (inode_ref) del_inode_ref = 1; btrfs_release_path(path); dir_item = btrfs_lookup_dir_item(NULL, root, path, parent_ino, name, namelen, 0); if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } if (dir_item) del_dir_item = 1; btrfs_release_path(path); dir_item = btrfs_lookup_dir_index(NULL, root, path, parent_ino, name, namelen, index, 0); /* * Since lookup_dir_index() will return -ENOENT when not found, * we need to do extra check. */ if (IS_ERR(dir_item) && PTR_ERR(dir_item) == -ENOENT) dir_item = NULL; if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } if (dir_item) del_dir_index = 1; btrfs_release_path(path); if (!del_inode_ref && !del_dir_item && !del_dir_index) { /* All not found, shouldn't happen */ ret = -ENOENT; goto out; } if (del_inode_ref) { /* Only decrease nlink when deleting inode_ref */ key.objectid = ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret) { if (ret > 0) ret = -ENOENT; goto out; } inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); nlinks = btrfs_inode_nlink(path->nodes[0], inode_item); if (nlinks > 0) nlinks--; btrfs_set_inode_nlink(path->nodes[0], inode_item, nlinks); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(path); /* For nlinks == 0, add it to orphan list if needed */ if (nlinks == 0 && add_orphan) { ret = btrfs_add_orphan_item(trans, root, path, ino); if (ret < 0) goto out; btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(path); } ret = btrfs_del_inode_ref(trans, root, name, namelen, ino, parent_ino, &index); if (ret < 0) goto out; } if (del_dir_index) { dir_item = btrfs_lookup_dir_index(trans, root, path, parent_ino, name, namelen, index, -1); if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } if (!dir_item) { ret = -ENOENT; goto out; } ret = btrfs_delete_one_dir_name(trans, root, path, dir_item); if (ret) goto out; btrfs_release_path(path); /* Update inode size of the parent inode */ key.objectid = parent_ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(trans, root, &key, path, 1, 1); if (ret) goto out; inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); inode_size = btrfs_inode_size(path->nodes[0], inode_item); if (inode_size >= namelen) inode_size -= namelen; btrfs_set_inode_size(path->nodes[0], inode_item, inode_size); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(path); } if (del_dir_item) { dir_item = btrfs_lookup_dir_item(trans, root, path, parent_ino, name, namelen, -1); if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } if (!dir_item) { ret = -ENOENT; goto out; } ret = btrfs_delete_one_dir_name(trans, root, path, dir_item); if (ret < 0) goto out; btrfs_release_path(path); /* Update inode size of the parent inode */ key.objectid = parent_ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(trans, root, &key, path, 1, 1); if (ret) goto out; inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); inode_size = btrfs_inode_size(path->nodes[0], inode_item); if (inode_size >= namelen) inode_size -= namelen; btrfs_set_inode_size(path->nodes[0], inode_item, inode_size); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(path); } out: btrfs_free_path(path); return ret; } /* Fill inode item with 'mode'. Uid/gid to root/root */ static void fill_inode_item(struct btrfs_trans_handle *trans, struct btrfs_inode_item *inode_item, u32 mode, u32 nlink) { time_t now = time(NULL); btrfs_set_stack_inode_generation(inode_item, trans->transid); btrfs_set_stack_inode_uid(inode_item, 0); btrfs_set_stack_inode_gid(inode_item, 0); btrfs_set_stack_inode_size(inode_item, 0); btrfs_set_stack_inode_mode(inode_item, mode); btrfs_set_stack_inode_nlink(inode_item, nlink); btrfs_set_stack_timespec_sec(&inode_item->atime, now); btrfs_set_stack_timespec_nsec(&inode_item->atime, 0); btrfs_set_stack_timespec_sec(&inode_item->mtime, now); btrfs_set_stack_timespec_nsec(&inode_item->mtime, 0); btrfs_set_stack_timespec_sec(&inode_item->ctime, now); btrfs_set_stack_timespec_nsec(&inode_item->ctime, 0); } /* * Unlike kernel btrfs_new_inode(), we only create the INODE_ITEM, without * its backref. * The backref is added by btrfs_add_link(). */ int btrfs_new_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 ino, u32 mode) { struct btrfs_inode_item inode_item = {0}; int ret = 0; fill_inode_item(trans, &inode_item, mode, 0); ret = btrfs_insert_inode(trans, root, ino, &inode_item); return ret; } /* * Change inode flags to given value */ int btrfs_change_inode_flags(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 ino, u64 flags) { struct btrfs_inode_item *item; struct btrfs_path *path; struct btrfs_key key; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; ret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (ret > 0) { ret = -ENOENT; goto out; } if (ret < 0) goto out; item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); btrfs_set_inode_flags(path->nodes[0], item, flags); btrfs_mark_buffer_dirty(path->nodes[0]); out: btrfs_free_path(path); return ret; } /* * Make a dir under the parent inode 'parent_ino' with 'name' * and 'mode', The owner will be root/root. */ int btrfs_mkdir(struct btrfs_trans_handle *trans, struct btrfs_root *root, char *name, int namelen, u64 parent_ino, u64 *ino, int mode) { struct btrfs_dir_item *dir_item; struct btrfs_path *path; u64 ret_ino = 0; int ret = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; if (ino && *ino) ret_ino = *ino; dir_item = btrfs_lookup_dir_item(NULL, root, path, parent_ino, name, namelen, 0); if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } if (dir_item) { struct btrfs_key found_key; /* * Already have conflicting name, check if it is a dir. * Either way, no need to continue. */ btrfs_dir_item_key_to_cpu(path->nodes[0], dir_item, &found_key); ret_ino = found_key.objectid; if (btrfs_dir_type(path->nodes[0], dir_item) != BTRFS_FT_DIR) ret = -EEXIST; goto out; } if (!ret_ino) /* * This is *UNSAFE* if some leaf is corrupted, * only used as a fallback method. Caller should either * ensure the fs is OK or pass ino with unused inode number. */ ret = btrfs_find_free_objectid(NULL, root, parent_ino, &ret_ino); if (ret) goto out; ret = btrfs_new_inode(trans, root, ret_ino, mode | S_IFDIR); if (ret) goto out; ret = btrfs_add_link(trans, root, ret_ino, parent_ino, name, namelen, BTRFS_FT_DIR, NULL, 1, 0); if (ret) goto out; out: btrfs_free_path(path); if (ret == 0 && ino) *ino = ret_ino; return ret; } struct btrfs_root *btrfs_mksubvol(struct btrfs_root *root, const char *base, u64 root_objectid, bool convert) { struct btrfs_trans_handle *trans; struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root *new_root = NULL; struct btrfs_path path; struct btrfs_inode_item *inode_item; struct extent_buffer *leaf; struct btrfs_key key; u64 dirid = btrfs_root_dirid(&root->root_item); u64 index = 2; char buf[BTRFS_NAME_LEN + 1]; /* for snprintf null */ int len; int i; int ret; len = strlen(base); if (len == 0 || len > BTRFS_NAME_LEN) return NULL; btrfs_init_path(&path); key.objectid = dirid; key.type = BTRFS_DIR_INDEX_KEY; key.offset = (u64)-1; ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); if (ret <= 0) { error("search for DIR_INDEX dirid %llu failed: %d", (unsigned long long)dirid, ret); goto fail; } if (path.slots[0] > 0) { path.slots[0]--; btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]); if (key.objectid == dirid && key.type == BTRFS_DIR_INDEX_KEY) index = key.offset + 1; } btrfs_release_path(&path); trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { error("unable to start transaction"); goto fail; } key.objectid = dirid; key.offset = 0; key.type = BTRFS_INODE_ITEM_KEY; ret = btrfs_lookup_inode(trans, root, &path, &key, 1); if (ret) { error("search for INODE_ITEM %llu failed: %d", (unsigned long long)dirid, ret); goto fail; } leaf = path.nodes[0]; inode_item = btrfs_item_ptr(leaf, path.slots[0], struct btrfs_inode_item); key.objectid = root_objectid; key.offset = (u64)-1; key.type = BTRFS_ROOT_ITEM_KEY; memcpy(buf, base, len); if (convert) { for (i = 0; i < 1024; i++) { ret = btrfs_insert_dir_item(trans, root, buf, len, dirid, &key, BTRFS_FT_DIR, index); if (ret != -EEXIST) break; len = snprintf(buf, ARRAY_SIZE(buf), "%s%d", base, i); if (len < 1 || len > BTRFS_NAME_LEN) { ret = -EINVAL; break; } } } else { ret = btrfs_insert_dir_item(trans, root, buf, len, dirid, &key, BTRFS_FT_DIR, index); } if (ret) goto fail; btrfs_set_inode_size(leaf, inode_item, len * 2 + btrfs_inode_size(leaf, inode_item)); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(&path); /* add the backref first */ ret = btrfs_add_root_ref(trans, tree_root, root_objectid, BTRFS_ROOT_BACKREF_KEY, root->root_key.objectid, dirid, index, buf, len); if (ret) { error("unable to add root backref for %llu: %d", root->root_key.objectid, ret); goto fail; } /* now add the forward ref */ ret = btrfs_add_root_ref(trans, tree_root, root->root_key.objectid, BTRFS_ROOT_REF_KEY, root_objectid, dirid, index, buf, len); if (ret) { error("unable to add root ref for %llu: %d", root->root_key.objectid, ret); goto fail; } ret = btrfs_commit_transaction(trans, root); if (ret) { error("transaction commit failed: %d", ret); goto fail; } new_root = btrfs_read_fs_root(fs_info, &key); if (IS_ERR(new_root)) { error("unable to fs read root: %lu", PTR_ERR(new_root)); new_root = NULL; } fail: btrfs_init_path(&path); return new_root; } /* * Walk the tree of allocated inodes and find a hole. */ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 dirid, u64 *objectid) { struct btrfs_path *path; struct btrfs_key key; int ret; int slot = 0; u64 last_ino = 0; int start_found; struct extent_buffer *l; struct btrfs_key search_key; u64 search_start = dirid; path = btrfs_alloc_path(); if (!path) return -ENOMEM; search_start = root->last_inode_alloc; search_start = max((unsigned long long)search_start, BTRFS_FIRST_FREE_OBJECTID); search_key.objectid = search_start; search_key.offset = 0; search_key.type = 0; btrfs_init_path(path); start_found = 0; ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0); if (ret < 0) goto error; if (path->slots[0] > 0) path->slots[0]--; while (1) { l = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(l)) { ret = btrfs_next_leaf(root, path); if (ret == 0) continue; if (ret < 0) goto error; if (!start_found) { *objectid = search_start; start_found = 1; goto found; } *objectid = last_ino > search_start ? last_ino : search_start; goto found; } btrfs_item_key_to_cpu(l, &key, slot); if (key.objectid >= search_start) { if (start_found) { if (last_ino < search_start) last_ino = search_start; if (key.objectid > last_ino) { *objectid = last_ino; goto found; } } } start_found = 1; last_ino = key.objectid + 1; path->slots[0]++; } // FIXME -ENOSPC found: root->last_inode_alloc = *objectid; btrfs_free_path(path); BUG_ON(*objectid < search_start); return 0; error: btrfs_free_path(path); return ret; }