forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
129 lines
3.2 KiB
129 lines
3.2 KiB
// 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, |
|
};
|
|
|