fe5de5859d
Previously, directory inodes are directly handled with page cache interfaces. In order to support sub-page directory blocks and folios, let's convert them into the latest metabuf infrastructure as well and this patch addresses the readdir case first. Link: https://lore.kernel.org/r/20220316012246.95131-1-hsiangkao@linux.alibaba.com Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
132 lines
3.2 KiB
C
132 lines
3.2 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 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, unsigned int *ofs,
|
|
unsigned int nameoff, unsigned int maxsize)
|
|
{
|
|
struct erofs_dirent *de = dentry_blk + *ofs;
|
|
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;
|
|
*ofs += sizeof(struct erofs_dirent);
|
|
}
|
|
*ofs = maxsize;
|
|
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 >= PAGE_SIZE) {
|
|
erofs_err(dir->i_sb,
|
|
"invalid de[0].nameoff %u @ nid %llu",
|
|
nameoff, EROFS_I(dir)->nid);
|
|
err = -EFSCORRUPTED;
|
|
goto skip_this;
|
|
}
|
|
|
|
maxsize = min_t(unsigned int,
|
|
dirsize - ctx->pos + ofs, PAGE_SIZE);
|
|
|
|
/* search dirents at the arbitrary position */
|
|
if (initial) {
|
|
initial = false;
|
|
|
|
ofs = roundup(ofs, sizeof(struct erofs_dirent));
|
|
if (ofs >= nameoff)
|
|
goto skip_this;
|
|
}
|
|
|
|
err = erofs_fill_dentries(dir, ctx, de, &ofs,
|
|
nameoff, maxsize);
|
|
skip_this:
|
|
ctx->pos = blknr_to_addr(i) + ofs;
|
|
|
|
if (err)
|
|
break;
|
|
++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,
|
|
};
|