diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c index 1f9e31d285cc90f13ea561b168c7f1a5769b18dc..956814d6604a5ca160cbeb52db31b5bd4744a9ac 100644 --- a/fs/nilfs2/dir.c +++ b/fs/nilfs2/dir.c @@ -192,19 +192,24 @@ static bool nilfs_check_page(struct page *page) return false; } -static struct page *nilfs_get_page(struct inode *dir, unsigned long n) +static void *nilfs_get_page(struct inode *dir, unsigned long n, + struct page **pagep) { struct address_space *mapping = dir->i_mapping; struct page *page = read_mapping_page(mapping, n, NULL); + void *kaddr; - if (!IS_ERR(page)) { - kmap(page); - if (unlikely(!PageChecked(page))) { - if (PageError(page) || !nilfs_check_page(page)) - goto fail; - } + if (IS_ERR(page)) + return page; + + kaddr = kmap(page); + if (unlikely(!PageChecked(page))) { + if (!nilfs_check_page(page)) + goto fail; } - return page; + + *pagep = page; + return kaddr; fail: nilfs_put_page(page); @@ -281,14 +286,14 @@ static int nilfs_readdir(struct file *file, struct dir_context *ctx) for ( ; n < npages; n++, offset = 0) { char *kaddr, *limit; struct nilfs_dir_entry *de; - struct page *page = nilfs_get_page(inode, n); + struct page *page; - if (IS_ERR(page)) { + kaddr = nilfs_get_page(inode, n, &page); + if (IS_ERR(kaddr)) { nilfs_error(sb, "bad page in #%lu", inode->i_ino); ctx->pos += PAGE_SIZE - offset; return -EIO; } - kaddr = page_address(page); de = (struct nilfs_dir_entry *)(kaddr + offset); limit = kaddr + nilfs_last_byte(inode, n) - NILFS_DIR_REC_LEN(1); @@ -351,11 +356,9 @@ nilfs_find_entry(struct inode *dir, const struct qstr *qstr, start = 0; n = start; do { - char *kaddr; + char *kaddr = nilfs_get_page(dir, n, &page); - page = nilfs_get_page(dir, n); - if (!IS_ERR(page)) { - kaddr = page_address(page); + if (!IS_ERR(kaddr)) { de = (struct nilfs_dir_entry *)kaddr; kaddr += nilfs_last_byte(dir, n) - reclen; while ((char *) de <= kaddr) { @@ -393,15 +396,39 @@ nilfs_find_entry(struct inode *dir, const struct qstr *qstr, struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct page **p) { - struct page *page = nilfs_get_page(dir, 0); - struct nilfs_dir_entry *de = NULL; + struct page *page; + struct nilfs_dir_entry *de, *next_de; + size_t limit; + char *msg; + + de = nilfs_get_page(dir, 0, &page); + if (IS_ERR(de)) + return NULL; + + limit = nilfs_last_byte(dir, 0); /* is a multiple of chunk size */ + if (unlikely(!limit || le64_to_cpu(de->inode) != dir->i_ino || + !nilfs_match(1, ".", de))) { + msg = "missing '.'"; + goto fail; + } - if (!IS_ERR(page)) { - de = nilfs_next_entry( - (struct nilfs_dir_entry *)page_address(page)); - *p = page; + next_de = nilfs_next_entry(de); + /* + * If "next_de" has not reached the end of the chunk, there is + * at least one more record. Check whether it matches "..". + */ + if (unlikely((char *)next_de == (char *)de + nilfs_chunk_size(dir) || + !nilfs_match(2, "..", next_de))) { + msg = "missing '..'"; + goto fail; } - return de; + *p = page; + return next_de; + +fail: + nilfs_error(dir->i_sb, "directory #%lu %s", dir->i_ino, msg); + nilfs_put_page(page); + return NULL; } ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr) @@ -465,12 +492,11 @@ int nilfs_add_link(struct dentry *dentry, struct inode *inode) for (n = 0; n <= npages; n++) { char *dir_end; - page = nilfs_get_page(dir, n); - err = PTR_ERR(page); - if (IS_ERR(page)) + kaddr = nilfs_get_page(dir, n, &page); + err = PTR_ERR(kaddr); + if (IS_ERR(kaddr)) goto out; lock_page(page); - kaddr = page_address(page); dir_end = kaddr + nilfs_last_byte(dir, n); de = (struct nilfs_dir_entry *)kaddr; kaddr += PAGE_SIZE - reclen; @@ -633,11 +659,10 @@ int nilfs_empty_dir(struct inode *inode) char *kaddr; struct nilfs_dir_entry *de; - page = nilfs_get_page(inode, i); - if (IS_ERR(page)) + kaddr = nilfs_get_page(inode, i, &page); + if (IS_ERR(kaddr)) continue; - kaddr = page_address(page); de = (struct nilfs_dir_entry *)kaddr; kaddr += nilfs_last_byte(inode, i) - NILFS_DIR_REC_LEN(1);