From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- fs/erofs/dir.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 fs/erofs/dir.c (limited to 'fs/erofs/dir.c') diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c new file mode 100644 index 000000000..ecf28f66b --- /dev/null +++ b/fs/erofs/dir.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017-2018 HUAWEI, Inc. + * https://www.huawei.com/ + * Copyright (C) 2022, Alibaba Cloud + */ +#include "internal.h" + +static void debug_one_dentry(unsigned char d_type, const char *de_name, + unsigned int de_namelen) +{ +#ifdef CONFIG_EROFS_FS_DEBUG + /* since the on-disk name could not have the trailing '\0' */ + unsigned char dbg_namebuf[EROFS_NAME_LEN + 1]; + + memcpy(dbg_namebuf, de_name, de_namelen); + dbg_namebuf[de_namelen] = '\0'; + + erofs_dbg("found dirent %s de_len %u d_type %d", dbg_namebuf, + de_namelen, d_type); +#endif +} + +static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx, + void *dentry_blk, struct erofs_dirent *de, + unsigned int nameoff, unsigned int maxsize) +{ + const struct erofs_dirent *end = dentry_blk + nameoff; + + while (de < end) { + const char *de_name; + unsigned int de_namelen; + unsigned char d_type; + + d_type = fs_ftype_to_dtype(de->file_type); + + nameoff = le16_to_cpu(de->nameoff); + de_name = (char *)dentry_blk + nameoff; + + /* the last dirent in the block? */ + if (de + 1 >= end) + de_namelen = strnlen(de_name, maxsize - nameoff); + else + de_namelen = le16_to_cpu(de[1].nameoff) - nameoff; + + /* a corrupted entry is found */ + if (nameoff + de_namelen > maxsize || + de_namelen > EROFS_NAME_LEN) { + erofs_err(dir->i_sb, "bogus dirent @ nid %llu", + EROFS_I(dir)->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; + } + + debug_one_dentry(d_type, de_name, de_namelen); + if (!dir_emit(ctx, de_name, de_namelen, + le64_to_cpu(de->nid), d_type)) + /* stopped by some reason */ + return 1; + ++de; + ctx->pos += sizeof(struct erofs_dirent); + } + return 0; +} + +static int erofs_readdir(struct file *f, struct dir_context *ctx) +{ + struct inode *dir = file_inode(f); + struct erofs_buf buf = __EROFS_BUF_INITIALIZER; + const size_t dirsize = i_size_read(dir); + unsigned int i = ctx->pos / EROFS_BLKSIZ; + unsigned int ofs = ctx->pos % EROFS_BLKSIZ; + int err = 0; + bool initial = true; + + while (ctx->pos < dirsize) { + struct erofs_dirent *de; + unsigned int nameoff, maxsize; + + de = erofs_bread(&buf, dir, i, EROFS_KMAP); + if (IS_ERR(de)) { + erofs_err(dir->i_sb, + "fail to readdir of logical block %u of nid %llu", + i, EROFS_I(dir)->nid); + err = PTR_ERR(de); + break; + } + + nameoff = le16_to_cpu(de->nameoff); + if (nameoff < sizeof(struct erofs_dirent) || + nameoff >= EROFS_BLKSIZ) { + erofs_err(dir->i_sb, + "invalid de[0].nameoff %u @ nid %llu", + nameoff, EROFS_I(dir)->nid); + err = -EFSCORRUPTED; + break; + } + + maxsize = min_t(unsigned int, + dirsize - ctx->pos + ofs, EROFS_BLKSIZ); + + /* search dirents at the arbitrary position */ + if (initial) { + initial = false; + + ofs = roundup(ofs, sizeof(struct erofs_dirent)); + ctx->pos = blknr_to_addr(i) + ofs; + if (ofs >= nameoff) + goto skip_this; + } + + err = erofs_fill_dentries(dir, ctx, de, (void *)de + ofs, + nameoff, maxsize); + if (err) + break; +skip_this: + ctx->pos = blknr_to_addr(i) + maxsize; + ++i; + ofs = 0; + } + erofs_put_metabuf(&buf); + return err < 0 ? err : 0; +} + +const struct file_operations erofs_dir_fops = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = erofs_readdir, +}; -- cgit v1.2.3