mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 21:38:32 +08:00
3acea5fc33
As the first step of converting hardcoded blocksize to that specified in on-disk superblock, convert all call sites of hardcoded blocksize to sb->s_blocksize except for: 1) use sbi->blkszbits instead of sb->s_blocksize in erofs_superblock_csum_verify() since sb->s_blocksize has not been updated with the on-disk blocksize yet when the function is called. 2) use inode->i_blkbits instead of sb->s_blocksize in erofs_bread(), since the inode operated on may be an anonymous inode in fscache mode. Currently the anonymous inode is allocated from an anonymous mount maintained in erofs, while in the near future we may allocate anonymous inodes from a generic API directly and thus have no access to the anonymous inode's i_sb. Thus we keep the block size in i_blkbits for anonymous inodes in fscache mode. Be noted that this patch only gets rid of the hardcoded blocksize, in preparation for actually setting the on-disk block size in the following patch. The hard limit of constraining the block size to PAGE_SIZE still exists until the next patch. Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Yue Hu <huyue2@coolpad.com> Reviewed-by: Chao Yu <chao@kernel.org> Link: https://lore.kernel.org/r/20230313135309.75269-2-jefflexu@linux.alibaba.com [ Gao Xiang: fold a patch to fix incorrect truncated offsets. ] Link: https://lore.kernel.org/r/20230413035734.15457-1-zhujia.zj@bytedance.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
111 lines
2.8 KiB
C
111 lines
2.8 KiB
C
// 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 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;
|
|
}
|
|
|
|
if (!dir_emit(ctx, de_name, de_namelen,
|
|
le64_to_cpu(de->nid), d_type))
|
|
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;
|
|
struct super_block *sb = dir->i_sb;
|
|
unsigned long bsz = sb->s_blocksize;
|
|
const size_t dirsize = i_size_read(dir);
|
|
unsigned int i = erofs_blknr(sb, ctx->pos);
|
|
unsigned int ofs = erofs_blkoff(sb, ctx->pos);
|
|
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(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 >= bsz) {
|
|
erofs_err(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, bsz);
|
|
|
|
/* search dirents at the arbitrary position */
|
|
if (initial) {
|
|
initial = false;
|
|
|
|
ofs = roundup(ofs, sizeof(struct erofs_dirent));
|
|
ctx->pos = erofs_pos(sb, 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 = erofs_pos(sb, 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,
|
|
};
|