Messages in this thread Patch in this message |  | | From | Zhihao Cheng <> | | Subject | [PATCH RFC 10/17] ubifs: repair: Create new root dir if there are no scanned files | | Date | Thu, 28 Dec 2023 09:41:05 +0800 |
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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 <chengzhihao1@huawei.com> --- fs/ubifs/repair.c | 187 +++++++++++++++++++++++++++++++++++++++++++++- fs/ubifs/repair.h | 6 ++ fs/ubifs/sb.c | 24 +----- fs/ubifs/ubifs.h | 28 +++++++ 4 files changed, 220 insertions(+), 25 deletions(-)
diff --git a/fs/ubifs/repair.c b/fs/ubifs/repair.c index 59b79481974a..c43150fff19d 100644 --- a/fs/ubifs/repair.c +++ b/fs/ubifs/repair.c @@ -50,9 +50,17 @@ static int init_repair_info(struct ubifs_info *c) err = -ENOMEM; goto free_used_lebs; } + c->repair->write_buf = vmalloc(c->leb_size); + if (!c->repair->write_buf) { + err = -ENOMEM; + goto free_lpts; + } + c->repair->head_lnum = -1; return 0; +free_lpts: + kfree(c->repair->lpts); free_used_lebs: bitmap_free(c->repair->used_lebs); free_repair: @@ -62,6 +70,7 @@ static int init_repair_info(struct ubifs_info *c) static void destroy_repair_info(struct ubifs_info *c) { + vfree(c->repair->write_buf); kfree(c->repair->lpts); bitmap_free(c->repair->used_lebs); kfree(c->repair); @@ -1745,6 +1754,171 @@ static int check_and_correct_files(struct ubifs_info *c) return 0; } +/** + * get_free_leb - get a free LEB according to @c->repair->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(c->repair->used_lebs, c->main_lebs, 0); + if (lnum >= c->main_lebs) { + ubifs_err(c, "No space left."); + return -ENOSPC; + } + set_bit(lnum, c->repair->used_lebs); + lnum += c->main_first; + + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + + c->repair->head_lnum = lnum; + c->repair->head_offs = 0; + + return 0; +} + +/** + * flush_write_buf - flush write buffer. + * @c: UBIFS file-system description object + * + * This function flush write buffer to LEB @c->repair->head_lnum, then set + * @c->repair->head_lnum to '-1'. + */ +static int flush_write_buf(struct ubifs_info *c) +{ + int len, pad, err; + + if (!c->repair->head_offs) + return 0; + + len = ALIGN(c->repair->head_offs, c->min_io_size); + pad = len - c->repair->head_offs; + if (pad) + ubifs_pad(c, c->repair->write_buf + c->repair->head_offs, pad); + + err = ubifs_leb_write(c, c->repair->head_lnum, c->repair->write_buf, 0, + len); + if (err) + return err; + + c->repair->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 (c->repair->head_lnum == -1) { +get_new: + err = get_free_leb(c); + if (err) + return err; + } + + if (len > c->leb_size - c->repair->head_offs) { + err = flush_write_buf(c); + if (err) + return err; + + goto get_new; + } + + *lnum = c->repair->head_lnum; + *offs = c->repair->head_offs; + c->repair->head_offs += ALIGN(len, 8); + + return 0; +} + +static void copy_node_data(struct ubifs_info *c, void *node, int offs, int len) +{ + memcpy(c->repair->write_buf + offs, node, len); + memset(c->repair->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; + ubifs_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, &c->repair->scanned_files.rb_node); + rb_insert_color(&file->rb, &c->repair->scanned_files); + +out: + kfree(ino); + return err; +} + static char *get_file_name(struct ubifs_info *c, struct scanned_file *file) { static char name[UBIFS_MAX_NLEN + 1]; @@ -1786,9 +1960,10 @@ static void parse_node_location(struct ubifs_info *c, struct scanned_node *sn) * * 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) @@ -1799,6 +1974,14 @@ static int traverse_files_and_nodes(struct ubifs_info *c) struct scanned_dent_node *dent_node; struct scanned_data_node *data_node; + if (rb_first(&c->repair->scanned_files) == NULL) { + /* No scanned files. Create root dir. */ + ubifs_msg(c, "No scanned files, create empty filesystem"); + err = create_root(c); + if (err) + return err; + } + ubifs_msg(c, "Step 8: Record used LEBs"); for (node = rb_first(&c->repair->scanned_files); node; node = rb_next(node)) { diff --git a/fs/ubifs/repair.h b/fs/ubifs/repair.h index 2ab885fefee0..e3b879b3f999 100644 --- a/fs/ubifs/repair.h +++ b/fs/ubifs/repair.h @@ -165,11 +165,17 @@ struct lprops { * @usen_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_repair_info { unsigned long *used_lebs; struct lprops *lpts; struct rb_root scanned_files; + void *write_buf; + int head_lnum; + int head_offs; }; #endif /* !__UBIFS_REPAIR_H__ */ diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c index e7693b94e5b5..d46798fd548b 100644 --- a/fs/ubifs/sb.c +++ b/fs/ubifs/sb.c @@ -86,8 +86,6 @@ static int create_default_filesystem(struct ubifs_info *c) int min_leb_cnt = UBIFS_MIN_LEB_CNT; int idx_node_size; long long tmp64, main_bytes; - __le64 tmp_le64; - struct timespec64 ts; u8 hash[UBIFS_HASH_ARR_SZ]; u8 hash_lpt[UBIFS_HASH_ARR_SZ]; @@ -287,27 +285,7 @@ static int create_default_filesystem(struct ubifs_info *c) dbg_gen("default root indexing node created LEB %d:0", main_first + DEFAULT_IDX_LEB); - /* 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); - - ktime_get_coarse_real_ts64(&ts); - tmp_le64 = cpu_to_le64(ts.tv_sec); - 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); - + ubifs_init_root_ino(c, ino); dbg_gen("root inode created at LEB %d:0", main_first + DEFAULT_DATA_LEB); diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 726161f46f3c..7d66440623cb 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -2207,6 +2207,34 @@ int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, extern const struct fscrypt_operations ubifs_crypt_operations; +static inline void ubifs_init_root_ino(struct ubifs_info *c, + struct ubifs_ino_node *ino) +{ + __le64 tmp_le64; + struct timespec64 ts; + + /* 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); + + ktime_get_coarse_real_ts64(&ts); + tmp_le64 = cpu_to_le64(ts.tv_sec); + 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); +} + /* Normal UBIFS messages */ __printf(2, 3) void ubifs_msg(const struct ubifs_info *c, const char *fmt, ...); -- 2.31.1
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