// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2024, Huawei Technologies Co, Ltd. * * Authors: Zhihao Cheng */ #include #include #include #include #include "linux_err.h" #include "bitops.h" #include "kmem.h" #include "ubifs.h" #include "defs.h" #include "debug.h" #include "key.h" #include "misc.h" #include "fsck.ubifs.h" /** * scanned_info - nodes and files information from scanning. * @valid_inos: the tree of scanned inode nodes with 'nlink > 0' * @del_inos: the tree of scanned inode nodes with 'nlink = 0' * @valid_dents: the tree of scanned dentry nodes with 'inum > 0' * @del_dents: the tree of scanned dentry nodes with 'inum = 0' */ struct scanned_info { struct rb_root valid_inos; struct rb_root del_inos; struct rb_root valid_dents; struct rb_root del_dents; }; static int init_rebuild_info(struct ubifs_info *c) { int err; c->sbuf = vmalloc(c->leb_size); if (!c->sbuf) { log_err(c, errno, "can not allocate sbuf"); return -ENOMEM; } FSCK(c)->rebuild = kzalloc(sizeof(struct ubifs_rebuild_info), GFP_KERNEL); if (!FSCK(c)->rebuild) { err = -ENOMEM; log_err(c, errno, "can not allocate rebuild info"); goto free_sbuf; } FSCK(c)->rebuild->scanned_files = RB_ROOT; FSCK(c)->rebuild->used_lebs = kcalloc(BITS_TO_LONGS(c->main_lebs), sizeof(unsigned long), GFP_KERNEL); if (!FSCK(c)->rebuild->used_lebs) { err = -ENOMEM; log_err(c, errno, "can not allocate bitmap of used lebs"); goto free_rebuild; } return 0; free_rebuild: kfree(FSCK(c)->rebuild); free_sbuf: vfree(c->sbuf); return err; } static void destroy_rebuild_info(struct ubifs_info *c) { kfree(FSCK(c)->rebuild->used_lebs); kfree(FSCK(c)->rebuild); vfree(c->sbuf); } /** * insert_or_update_ino_node - insert or update inode node. * @c: UBIFS file-system description object * @new_ino: new inode node * @tree: a tree to record valid/deleted inode node info * * This function inserts @new_ino into the @tree, or updates inode node * if it already exists in the tree. Returns zero in case of success, a * negative error code in case of failure. */ static int insert_or_update_ino_node(struct ubifs_info *c, struct scanned_ino_node *new_ino, struct rb_root *tree) { int cmp; struct scanned_ino_node *ino_node, *old_ino_node = NULL; struct rb_node **p, *parent = NULL; p = &tree->rb_node; while (*p) { parent = *p; ino_node = rb_entry(parent, struct scanned_ino_node, rb); cmp = keys_cmp(c, &new_ino->key, &ino_node->key); if (cmp < 0) { p = &(*p)->rb_left; } else if (cmp > 0) { p = &(*p)->rb_right; } else { old_ino_node = ino_node; break; } } if (old_ino_node) { if (old_ino_node->header.sqnum < new_ino->header.sqnum) { size_t len = offsetof(struct scanned_ino_node, rb); memcpy(old_ino_node, new_ino, len); } return 0; } ino_node = kmalloc(sizeof(struct scanned_ino_node), GFP_KERNEL); if (!ino_node) return -ENOMEM; *ino_node = *new_ino; rb_link_node(&ino_node->rb, parent, p); rb_insert_color(&ino_node->rb, tree); return 0; } /** * insert_or_update_dent_node - insert or update dentry node. * @c: UBIFS file-system description object * @new_dent: new dentry node * @tree: a tree to record valid/deleted dentry node info * * This function inserts @new_dent into the @tree, or updates dent node * if it already exists in the tree. Returns zero in case of success, a * negative error code in case of failure. */ static int insert_or_update_dent_node(struct ubifs_info *c, struct scanned_dent_node *new_dent, struct rb_root *tree) { int cmp, nlen; struct scanned_dent_node *dent_node, *old_dent_node = NULL; struct rb_node **p, *parent = NULL; p = &tree->rb_node; while (*p) { parent = *p; dent_node = rb_entry(parent, struct scanned_dent_node, rb); cmp = keys_cmp(c, &new_dent->key, &dent_node->key); if (cmp < 0) { p = &(*p)->rb_left; } else if (cmp > 0) { p = &(*p)->rb_right; } else { nlen = min(new_dent->nlen, dent_node->nlen); cmp = strncmp(new_dent->name, dent_node->name, nlen) ? : new_dent->nlen - dent_node->nlen; if (cmp < 0) { p = &(*p)->rb_left; } else if (cmp > 0) { p = &(*p)->rb_right; } else { old_dent_node = dent_node; break; } } } if (old_dent_node) { if (old_dent_node->header.sqnum < new_dent->header.sqnum) { size_t len = offsetof(struct scanned_dent_node, rb); memcpy(old_dent_node, new_dent, len); } return 0; } dent_node = kmalloc(sizeof(struct scanned_dent_node), GFP_KERNEL); if (!dent_node) return -ENOMEM; *dent_node = *new_dent; rb_link_node(&dent_node->rb, parent, p); rb_insert_color(&dent_node->rb, tree); return 0; } /** * process_scanned_node - process scanned node. * @c: UBIFS file-system description object * @lnum: logical eraseblock number * @snod: scanned node * @si: records nodes and files information during scanning * * This function parses, checks and records scanned node information. * Returns zero in case of success, 1% if the scanned LEB doesn't hold file * data and should be ignored(eg. index LEB), a negative error code in case * of failure. */ static int process_scanned_node(struct ubifs_info *c, int lnum, struct ubifs_scan_node *snod, struct scanned_info *si) { ino_t inum; int offs = snod->offs; void *node = snod->node; union ubifs_key *key = &snod->key; struct rb_root *tree; struct scanned_node *sn; struct scanned_ino_node ino_node; struct scanned_dent_node dent_node; struct scanned_data_node data_node; struct scanned_trun_node trun_node; switch (snod->type) { case UBIFS_INO_NODE: { if (!parse_ino_node(c, lnum, offs, node, key, &ino_node)) return 0; tree = &si->del_inos; if (ino_node.nlink) tree = &si->valid_inos; return insert_or_update_ino_node(c, &ino_node, tree); } case UBIFS_DENT_NODE: case UBIFS_XENT_NODE: { if (!parse_dent_node(c, lnum, offs, node, key, &dent_node)) return 0; tree = &si->del_dents; if (dent_node.inum) tree = &si->valid_dents; return insert_or_update_dent_node(c, &dent_node, tree); } case UBIFS_DATA_NODE: { if (!parse_data_node(c, lnum, offs, node, key, &data_node)) return 0; inum = key_inum(c, key); sn = (struct scanned_node *)&data_node; break; } case UBIFS_TRUN_NODE: { if (!parse_trun_node(c, lnum, offs, node, key, &trun_node)) return 0; inum = le32_to_cpu(((struct ubifs_trun_node *)node)->inum); sn = (struct scanned_node *)&trun_node; break; } default: dbg_fsck("skip node type %d, at %d:%d, in %s", snod->type, lnum, offs, c->dev_name); return 1; } tree = &FSCK(c)->rebuild->scanned_files; return insert_or_update_file(c, tree, sn, key_type(c, key), inum); } /** * destroy_scanned_info - destroy scanned nodes. * @c: UBIFS file-system description object * @si: records nodes and files information during scanning * * Destroy scanned files and all data/dentry nodes attached to file, destroy * valid/deleted inode/dentry info. */ static void destroy_scanned_info(struct ubifs_info *c, struct scanned_info *si) { struct scanned_ino_node *ino_node; struct scanned_dent_node *dent_node; struct rb_node *this; destroy_file_tree(c, &FSCK(c)->rebuild->scanned_files); this = rb_first(&si->valid_inos); while (this) { ino_node = rb_entry(this, struct scanned_ino_node, rb); this = rb_next(this); rb_erase(&ino_node->rb, &si->valid_inos); kfree(ino_node); } this = rb_first(&si->del_inos); while (this) { ino_node = rb_entry(this, struct scanned_ino_node, rb); this = rb_next(this); rb_erase(&ino_node->rb, &si->del_inos); kfree(ino_node); } this = rb_first(&si->valid_dents); while (this) { dent_node = rb_entry(this, struct scanned_dent_node, rb); this = rb_next(this); rb_erase(&dent_node->rb, &si->valid_dents); kfree(dent_node); } this = rb_first(&si->del_dents); while (this) { dent_node = rb_entry(this, struct scanned_dent_node, rb); this = rb_next(this); rb_erase(&dent_node->rb, &si->del_dents); kfree(dent_node); } } /** * scan_nodes - scan node information from flash. * @c: UBIFS file-system description object * @si: records nodes and files information during scanning * * This function scans nodes from flash, all ino/dent nodes are split * into valid tree and deleted tree, all trun/data nodes are collected * into file, the file is inserted into @FSCK(c)->rebuild->scanned_files. */ static int scan_nodes(struct ubifs_info *c, struct scanned_info *si) { int lnum, err = 0; struct ubifs_scan_leb *sleb; struct ubifs_scan_node *snod; for (lnum = c->main_first; lnum < c->leb_cnt; ++lnum) { dbg_fsck("scan nodes at LEB %d, in %s", lnum, c->dev_name); sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); if (IS_ERR(sleb)) { if (PTR_ERR(sleb) != -EUCLEAN) return PTR_ERR(sleb); sleb = ubifs_recover_leb(c, lnum, 0, c->sbuf, -1); if (IS_ERR(sleb)) { if (PTR_ERR(sleb) != -EUCLEAN) return PTR_ERR(sleb); /* This LEB holds corrupted data, abandon it. */ continue; } } list_for_each_entry(snod, &sleb->nodes, list) { if (snod->sqnum > c->max_sqnum) c->max_sqnum = snod->sqnum; err = process_scanned_node(c, lnum, snod, si); if (err < 0) { log_err(c, 0, "process node failed at LEB %d, err %d", lnum, err); ubifs_scan_destroy(sleb); goto out; } else if (err == 1) { err = 0; break; } } ubifs_scan_destroy(sleb); } out: return err; } static struct scanned_ino_node * lookup_valid_ino_node(struct ubifs_info *c, struct scanned_info *si, struct scanned_ino_node *target) { int cmp; struct scanned_ino_node *ino_node; struct rb_node *p; p = si->valid_inos.rb_node; while (p) { ino_node = rb_entry(p, struct scanned_ino_node, rb); cmp = keys_cmp(c, &target->key, &ino_node->key); if (cmp < 0) { p = p->rb_left; } else if (cmp > 0) { p = p->rb_right; } else { if (target->header.sqnum > ino_node->header.sqnum) return ino_node; else return NULL; } } return NULL; } static struct scanned_dent_node * lookup_valid_dent_node(struct ubifs_info *c, struct scanned_info *si, struct scanned_dent_node *target) { int cmp, nlen; struct scanned_dent_node *dent_node; struct rb_node *p; p = si->valid_dents.rb_node; while (p) { dent_node = rb_entry(p, struct scanned_dent_node, rb); cmp = keys_cmp(c, &target->key, &dent_node->key); if (cmp < 0) { p = p->rb_left; } else if (cmp > 0) { p = p->rb_right; } else { nlen = min(target->nlen, dent_node->nlen); cmp = strncmp(target->name, dent_node->name, nlen) ? : target->nlen - dent_node->nlen; if (cmp < 0) { p = p->rb_left; } else if (cmp > 0) { p = p->rb_right; } else { if (target->header.sqnum > dent_node->header.sqnum) return dent_node; else return NULL; } } } return NULL; } /** * remove_del_nodes - remove deleted nodes from valid node tree. * @c: UBIFS file-system description object * @si: records nodes and files information during scanning * * This function compares sqnum between deleted node and corresponding valid * node, removes valid node from tree if the sqnum of deleted node is bigger. * Deleted ino/dent nodes will be removed from @si->del_inos/@si->del_dents * after this function finished. */ static void remove_del_nodes(struct ubifs_info *c, struct scanned_info *si) { struct scanned_ino_node *del_ino_node, *valid_ino_node; struct scanned_dent_node *del_dent_node, *valid_dent_node; struct rb_node *this; this = rb_first(&si->del_inos); while (this) { del_ino_node = rb_entry(this, struct scanned_ino_node, rb); this = rb_next(this); valid_ino_node = lookup_valid_ino_node(c, si, del_ino_node); if (valid_ino_node) { int lnum = del_ino_node->header.lnum; set_bit(lnum - c->main_first, FSCK(c)->rebuild->used_lebs); rb_erase(&valid_ino_node->rb, &si->valid_inos); kfree(valid_ino_node); } rb_erase(&del_ino_node->rb, &si->del_inos); kfree(del_ino_node); } this = rb_first(&si->del_dents); while (this) { del_dent_node = rb_entry(this, struct scanned_dent_node, rb); this = rb_next(this); valid_dent_node = lookup_valid_dent_node(c, si, del_dent_node); if (valid_dent_node) { int lnum = del_dent_node->header.lnum; set_bit(lnum - c->main_first, FSCK(c)->rebuild->used_lebs); rb_erase(&valid_dent_node->rb, &si->valid_dents); kfree(valid_dent_node); } rb_erase(&del_dent_node->rb, &si->del_dents); kfree(del_dent_node); } } /** * add_valid_nodes_into_file - add valid nodes into file. * @c: UBIFS file-system description object * @si: records nodes and files information during scanning * * This function adds valid nodes into corresponding file, all valid ino/dent * nodes will be removed from @si->valid_inos/@si->valid_dents if the function * is executed successfully. */ static int add_valid_nodes_into_file(struct ubifs_info *c, struct scanned_info *si) { int err, type; ino_t inum; struct scanned_node *sn; struct scanned_ino_node *ino_node; struct scanned_dent_node *dent_node; struct rb_node *this; struct rb_root *tree = &FSCK(c)->rebuild->scanned_files; this = rb_first(&si->valid_inos); while (this) { ino_node = rb_entry(this, struct scanned_ino_node, rb); this = rb_next(this); sn = (struct scanned_node *)ino_node; type = key_type(c, &ino_node->key); inum = key_inum(c, &ino_node->key); err = insert_or_update_file(c, tree, sn, type, inum); if (err) return err; rb_erase(&ino_node->rb, &si->valid_inos); kfree(ino_node); } this = rb_first(&si->valid_dents); while (this) { dent_node = rb_entry(this, struct scanned_dent_node, rb); this = rb_next(this); sn = (struct scanned_node *)dent_node; inum = dent_node->inum; type = key_type(c, &dent_node->key); err = insert_or_update_file(c, tree, sn, type, inum); if (err) return err; rb_erase(&dent_node->rb, &si->valid_dents); kfree(dent_node); } return 0; } /** * filter_invalid_files - filter out invalid files. * @c: UBIFS file-system description object * * This function filters out invalid files(eg. inconsistent types between * inode and dentry node, or missing inode/dentry node, or encrypted inode * has no encryption related xattrs, etc.). */ static void filter_invalid_files(struct ubifs_info *c) { struct rb_node *node; struct scanned_file *file; struct rb_root *tree = &FSCK(c)->rebuild->scanned_files; LIST_HEAD(tmp_list); /* Add all xattr files into a list. */ for (node = rb_first(tree); node; node = rb_next(node)) { file = rb_entry(node, struct scanned_file, rb); if (file->ino.is_xattr) list_add(&file->list, &tmp_list); } /* * Round 1: Traverse xattr files, check whether the xattr file is * valid, move valid xattr file into corresponding host file's subtree. */ while (!list_empty(&tmp_list)) { file = list_entry(tmp_list.next, struct scanned_file, list); list_del(&file->list); rb_erase(&file->rb, tree); if (!file_is_valid(c, file, tree)) { destroy_file_content(c, file); kfree(file); } } /* Round 2: Traverse non-xattr files. */ for (node = rb_first(tree); node; node = rb_next(node)) { file = rb_entry(node, struct scanned_file, rb); if (!file_is_valid(c, file, tree)) list_add(&file->list, &tmp_list); } /* Remove invalid files. */ while (!list_empty(&tmp_list)) { file = list_entry(tmp_list.next, struct scanned_file, list); list_del(&file->list); destroy_file_content(c, file); rb_erase(&file->rb, tree); kfree(file); } } /** * extract_dentry_tree - extract reachable directory entries. * @c: UBIFS file-system description object * * This function iterates all directory entries and remove those * unreachable ones. 'Unreachable' means that a directory entry can * not be searched from '/'. */ static void extract_dentry_tree(struct ubifs_info *c) { struct rb_node *node; struct scanned_file *file; struct rb_root *tree = &FSCK(c)->rebuild->scanned_files; LIST_HEAD(unreachable); for (node = rb_first(tree); node; node = rb_next(node)) { file = rb_entry(node, struct scanned_file, rb); /* * Since all xattr files are already attached to corresponding * host file, there are only non-xattr files in the file tree. */ ubifs_assert(c, !file->ino.is_xattr); if (!file_is_reachable(c, file, tree)) list_add(&file->list, &unreachable); } /* Remove unreachable files. */ while (!list_empty(&unreachable)) { file = list_entry(unreachable.next, struct scanned_file, list); dbg_fsck("remove unreachable file %lu, in %s", file->inum, c->dev_name); list_del(&file->list); destroy_file_content(c, file); rb_erase(&file->rb, tree); kfree(file); } } static const char *get_file_name(struct ubifs_info *c, struct scanned_file *file) { static char name[UBIFS_MAX_NLEN + 1]; struct rb_node *node; struct scanned_dent_node *dent_node; node = rb_first(&file->dent_nodes); if (!node) { ubifs_assert(c, file->inum == UBIFS_ROOT_INO); return "/"; } if (c->encrypted && !file->ino.is_xattr) /* Encrypted file name. */ return ""; /* Get name from any one dentry. */ dent_node = rb_entry(node, struct scanned_dent_node, rb); memcpy(name, dent_node->name, dent_node->nlen); /* @dent->name could be non '\0' terminated. */ name[dent_node->nlen] = '\0'; return name; } static void record_file_used_lebs(struct ubifs_info *c, struct scanned_file *file) { int lnum; struct rb_node *node; struct scanned_file *xattr_file; struct scanned_dent_node *dent_node; struct scanned_data_node *data_node; dbg_fsck("recovered file(inum:%lu name:%s type:%s), in %s", file->inum, get_file_name(c, file), file->ino.is_xattr ? "xattr" : ubifs_get_type_name(ubifs_get_dent_type(file->ino.mode)), c->dev_name); lnum = file->ino.header.lnum; set_bit(lnum - c->main_first, FSCK(c)->rebuild->used_lebs); if (file->trun.header.exist) { lnum = file->trun.header.lnum; set_bit(lnum - c->main_first, FSCK(c)->rebuild->used_lebs); } for (node = rb_first(&file->data_nodes); node; node = rb_next(node)) { data_node = rb_entry(node, struct scanned_data_node, rb); lnum = data_node->header.lnum; set_bit(lnum - c->main_first, FSCK(c)->rebuild->used_lebs); } for (node = rb_first(&file->dent_nodes); node; node = rb_next(node)) { dent_node = rb_entry(node, struct scanned_dent_node, rb); lnum = dent_node->header.lnum; set_bit(lnum - c->main_first, FSCK(c)->rebuild->used_lebs); } for (node = rb_first(&file->xattr_files); node; node = rb_next(node)) { xattr_file = rb_entry(node, struct scanned_file, rb); record_file_used_lebs(c, xattr_file); } } /** * record_used_lebs - record used LEBs. * @c: UBIFS file-system description object * * This function records all used LEBs which may hold useful nodes, then left * unused LEBs could be taken for storing new index tree. */ static void record_used_lebs(struct ubifs_info *c) { struct rb_node *node; struct scanned_file *file; struct rb_root *tree = &FSCK(c)->rebuild->scanned_files; for (node = rb_first(tree); node; node = rb_next(node)) { file = rb_entry(node, struct scanned_file, rb); record_file_used_lebs(c, file); } } /** * ubifs_rebuild_filesystem - Rebuild filesystem. * @c: UBIFS file-system description object * * Scanning nodes from UBI volume and rebuild filesystem. Any inconsistent * problems or corrupted data will be fixed. */ int ubifs_rebuild_filesystem(struct ubifs_info *c) { int err = 0; struct scanned_info si; si.valid_inos = si.del_inos = si.valid_dents = si.del_dents = RB_ROOT; log_out(c, "Start rebuilding filesystem (Notice: dropping data/recovering deleted data can't be awared)"); FSCK(c)->mode = REBUILD_MODE; err = init_rebuild_info(c); if (err) { exit_code |= FSCK_ERROR; return err; } /* Step 1: Scan valid/deleted nodes from volume. */ log_out(c, "Scan nodes"); err = scan_nodes(c, &si); if (err) { exit_code |= FSCK_ERROR; goto out; } /* Step 2: Remove deleted nodes from valid node tree. */ log_out(c, "Remove deleted nodes"); remove_del_nodes(c, &si); /* Step 3: Add valid nodes into file. */ log_out(c, "Add valid nodes into file"); err = add_valid_nodes_into_file(c, &si); if (err) { exit_code |= FSCK_ERROR; goto out; } /* Step 4: Drop invalid files. */ log_out(c, "Filter invalid files"); filter_invalid_files(c); /* Step 5: Extract reachable directory entries. */ log_out(c, "Extract reachable files"); extract_dentry_tree(c); /* Step 6: Check & correct files' information. */ log_out(c, "Check & correct file information"); err = check_and_correct_files(c); if (err) { exit_code |= FSCK_ERROR; goto out; } /* Step 7: Record used LEBs. */ log_out(c, "Record used LEBs"); record_used_lebs(c); out: destroy_scanned_info(c, &si); destroy_rebuild_info(c); return err; }