From 8ad286c3fc0662ea8a74b9e60fe27c3fe65aa9d2 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng Date: Mon, 11 Nov 2024 17:01:16 +0800 Subject: fsck.ubifs: rebuild_fs: Create new root dir if there are no scanned files This is a preparation for building TNC, there must at least one file in filesystem, if not, just create new root dir. Signed-off-by: Zhihao Cheng Signed-off-by: David Oberhollenzer --- ubifs-utils/fsck.ubifs/fsck.ubifs.h | 6 + ubifs-utils/fsck.ubifs/rebuild_fs.c | 213 +++++++++++++++++++++++++++++++++++- 2 files changed, 217 insertions(+), 2 deletions(-) (limited to 'ubifs-utils/fsck.ubifs') diff --git a/ubifs-utils/fsck.ubifs/fsck.ubifs.h b/ubifs-utils/fsck.ubifs/fsck.ubifs.h index cb7b400..fb72d8a 100644 --- a/ubifs-utils/fsck.ubifs/fsck.ubifs.h +++ b/ubifs-utils/fsck.ubifs/fsck.ubifs.h @@ -183,11 +183,17 @@ struct scanned_file { * @used_lebs: a bitmap used for recording used lebs * @lpts: lprops table * @scanned_files: tree of all scanned files + * @write_buf: write buffer for LEB @head_lnum + * @head_lnum: current writing LEB number + * @head_offs: current writing position in LEB @head_lnum */ struct ubifs_rebuild_info { unsigned long *used_lebs; struct ubifs_lprops *lpts; struct rb_root scanned_files; + void *write_buf; + int head_lnum; + int head_offs; }; /** diff --git a/ubifs-utils/fsck.ubifs/rebuild_fs.c b/ubifs-utils/fsck.ubifs/rebuild_fs.c index 1b03d6c..62bd412 100644 --- a/ubifs-utils/fsck.ubifs/rebuild_fs.c +++ b/ubifs-utils/fsck.ubifs/rebuild_fs.c @@ -65,9 +65,17 @@ static int init_rebuild_info(struct ubifs_info *c) log_err(c, errno, "can not allocate lpts"); goto free_used_lebs; } + FSCK(c)->rebuild->write_buf = vmalloc(c->leb_size); + if (!FSCK(c)->rebuild->write_buf) { + err = -ENOMEM; + goto free_lpts; + } + FSCK(c)->rebuild->head_lnum = -1; return 0; +free_lpts: + kfree(FSCK(c)->rebuild->lpts); free_used_lebs: kfree(FSCK(c)->rebuild->used_lebs); free_rebuild: @@ -79,6 +87,7 @@ free_sbuf: static void destroy_rebuild_info(struct ubifs_info *c) { + vfree(FSCK(c)->rebuild->write_buf); kfree(FSCK(c)->rebuild->lpts); kfree(FSCK(c)->rebuild->used_lebs); kfree(FSCK(c)->rebuild); @@ -661,6 +670,197 @@ static void extract_dentry_tree(struct ubifs_info *c) } } +static void init_root_ino(struct ubifs_info *c, struct ubifs_ino_node *ino) +{ +#define S_IRUGO (S_IRUSR|S_IRGRP|S_IROTH) +#define S_IXUGO (S_IXUSR|S_IXGRP|S_IXOTH) + __le64 tmp_le64; + + /* Create default root inode */ + ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); + ino->ch.node_type = UBIFS_INO_NODE; + ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); + ino->nlink = cpu_to_le32(2); + tmp_le64 = cpu_to_le64(time(NULL)); + ino->atime_sec = tmp_le64; + ino->ctime_sec = tmp_le64; + ino->mtime_sec = tmp_le64; + ino->atime_nsec = 0; + ino->ctime_nsec = 0; + ino->mtime_nsec = 0; + ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); + ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); + /* Set compression enabled by default */ + ino->flags = cpu_to_le32(UBIFS_COMPR_FL); +} + +/** + * get_free_leb - get a free LEB according to @FSCK(c)->rebuild->used_lebs. + * @c: UBIFS file-system description object + * + * This function tries to find a free LEB, %0 is returned if found, otherwise + * %ENOSPC is returned. + */ +static int get_free_leb(struct ubifs_info *c) +{ + int lnum, err; + + lnum = find_next_zero_bit(FSCK(c)->rebuild->used_lebs, c->main_lebs, 0); + if (lnum >= c->main_lebs) { + ubifs_err(c, "No space left."); + return -ENOSPC; + } + set_bit(lnum, FSCK(c)->rebuild->used_lebs); + lnum += c->main_first; + + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + + FSCK(c)->rebuild->head_lnum = lnum; + FSCK(c)->rebuild->head_offs = 0; + + return 0; +} + +/** + * flush_write_buf - flush write buffer. + * @c: UBIFS file-system description object + * + * This function flush write buffer to LEB @FSCK(c)->rebuild->head_lnum, then + * set @FSCK(c)->rebuild->head_lnum to '-1'. + */ +static int flush_write_buf(struct ubifs_info *c) +{ + int len, pad, err; + + if (!FSCK(c)->rebuild->head_offs) + return 0; + + len = ALIGN(FSCK(c)->rebuild->head_offs, c->min_io_size); + pad = len - FSCK(c)->rebuild->head_offs; + if (pad) + ubifs_pad(c, FSCK(c)->rebuild->write_buf + + FSCK(c)->rebuild->head_offs, pad); + + err = ubifs_leb_write(c, FSCK(c)->rebuild->head_lnum, + FSCK(c)->rebuild->write_buf, 0, len); + if (err) + return err; + + FSCK(c)->rebuild->head_lnum = -1; + + return 0; +} + +/** + * reserve_space - reserve enough space to write data. + * @c: UBIFS file-system description object + * @len: the length of written data + * @lnum: the write LEB number is returned here + * @offs: the write pos in LEB is returned here + * + * This function finds target position <@lnum, @offs> to write data with + * length of @len. + */ +static int reserve_space(struct ubifs_info *c, int len, int *lnum, int *offs) +{ + int err; + + if (FSCK(c)->rebuild->head_lnum == -1) { +get_new: + err = get_free_leb(c); + if (err) + return err; + } + + if (len > c->leb_size - FSCK(c)->rebuild->head_offs) { + err = flush_write_buf(c); + if (err) + return err; + + goto get_new; + } + + *lnum = FSCK(c)->rebuild->head_lnum; + *offs = FSCK(c)->rebuild->head_offs; + FSCK(c)->rebuild->head_offs += ALIGN(len, 8); + + return 0; +} + +static void copy_node_data(struct ubifs_info *c, void *node, int offs, int len) +{ + memcpy(FSCK(c)->rebuild->write_buf + offs, node, len); + memset(FSCK(c)->rebuild->write_buf + offs + len, 0xff, ALIGN(len, 8) - len); +} + +/** + * create_root - create root dir. + * @c: UBIFS file-system description object + * + * This function creates root dir. + */ +static int create_root(struct ubifs_info *c) +{ + int err, lnum, offs; + struct ubifs_ino_node *ino; + struct scanned_file *file; + + ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL); + if (!ino) + return -ENOMEM; + + c->max_sqnum = 0; + c->highest_inum = UBIFS_FIRST_INO; + init_root_ino(c, ino); + err = ubifs_prepare_node_hmac(c, ino, UBIFS_INO_NODE_SZ, -1, 1); + if (err) + goto out; + + err = reserve_space(c, UBIFS_INO_NODE_SZ, &lnum, &offs); + if (err) + goto out; + + copy_node_data(c, ino, offs, UBIFS_INO_NODE_SZ); + + err = flush_write_buf(c); + if (err) + goto out; + + file = kzalloc(sizeof(struct scanned_file), GFP_KERNEL); + if (!file) { + err = -ENOMEM; + goto out; + } + + file->inum = UBIFS_ROOT_INO; + file->dent_nodes = RB_ROOT; + file->data_nodes = RB_ROOT; + INIT_LIST_HEAD(&file->list); + + file->ino.header.exist = true; + file->ino.header.lnum = lnum; + file->ino.header.offs = offs; + file->ino.header.len = UBIFS_INO_NODE_SZ; + file->ino.header.sqnum = le64_to_cpu(ino->ch.sqnum); + ino_key_init(c, &file->ino.key, UBIFS_ROOT_INO); + file->ino.is_xattr = le32_to_cpu(ino->flags) & UBIFS_XATTR_FL; + file->ino.mode = le32_to_cpu(ino->mode); + file->calc_nlink = file->ino.nlink = le32_to_cpu(ino->nlink); + file->calc_xcnt = file->ino.xcnt = le32_to_cpu(ino->xattr_cnt); + file->calc_xsz = file->ino.xsz = le32_to_cpu(ino->xattr_size); + file->calc_xnms = file->ino.xnms = le32_to_cpu(ino->xattr_names); + file->calc_size = file->ino.size = le64_to_cpu(ino->size); + + rb_link_node(&file->rb, NULL, &FSCK(c)->rebuild->scanned_files.rb_node); + rb_insert_color(&file->rb, &FSCK(c)->rebuild->scanned_files); + +out: + kfree(ino); + return err; +} + static const char *get_file_name(struct ubifs_info *c, struct scanned_file *file) { static char name[UBIFS_MAX_NLEN + 1]; @@ -741,9 +941,10 @@ static void record_file_used_lebs(struct ubifs_info *c, * * This function traverses all nodes from valid files and does following * things: - * 1. Record all used LEBs which may hold useful nodes, then left unused + * 1. If there are no scanned files, create default empty filesystem. + * 2. Record all used LEBs which may hold useful nodes, then left unused * LEBs could be taken for storing new index tree. - * 2. Re-write data to prevent failed gc scanning in the subsequent mounting + * 3. Re-write data to prevent failed gc scanning in the subsequent mounting * process caused by corrupted data. */ static int traverse_files_and_nodes(struct ubifs_info *c) @@ -753,6 +954,14 @@ static int traverse_files_and_nodes(struct ubifs_info *c) struct scanned_file *file; struct rb_root *tree = &FSCK(c)->rebuild->scanned_files; + if (rb_first(tree) == NULL) { + /* No scanned files. Create root dir. */ + log_out(c, "No files found, create empty filesystem"); + err = create_root(c); + if (err) + return err; + } + log_out(c, "Record used LEBs"); for (node = rb_first(tree); node; node = rb_next(node)) { file = rb_entry(node, struct scanned_file, rb); -- cgit v1.2.3