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5b5c96c63d
- Use i_size instead of i_size_read() due to immutable fses; - Get rid of an unneeded goto since erofs_fill_dentries() also works; - Remove unnecessary lines. Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com> Link: https://lore.kernel.org/r/20240801112622.2164029-1-hongzhen@linux.alibaba.com Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
101 lines
2.7 KiB
C
101 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2017-2018 HUAWEI, Inc.
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* https://www.huawei.com/
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* Copyright (C) 2022, Alibaba Cloud
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*/
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#include "internal.h"
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static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx,
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void *dentry_blk, struct erofs_dirent *de,
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unsigned int nameoff0, unsigned int maxsize)
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{
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const struct erofs_dirent *end = dentry_blk + nameoff0;
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while (de < end) {
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unsigned char d_type = fs_ftype_to_dtype(de->file_type);
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unsigned int nameoff = le16_to_cpu(de->nameoff);
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const char *de_name = (char *)dentry_blk + nameoff;
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unsigned int de_namelen;
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/* the last dirent in the block? */
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if (de + 1 >= end)
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de_namelen = strnlen(de_name, maxsize - nameoff);
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else
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de_namelen = le16_to_cpu(de[1].nameoff) - nameoff;
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/* a corrupted entry is found */
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if (nameoff + de_namelen > maxsize ||
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de_namelen > EROFS_NAME_LEN) {
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erofs_err(dir->i_sb, "bogus dirent @ nid %llu",
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EROFS_I(dir)->nid);
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DBG_BUGON(1);
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return -EFSCORRUPTED;
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}
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if (!dir_emit(ctx, de_name, de_namelen,
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le64_to_cpu(de->nid), d_type))
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return 1;
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++de;
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ctx->pos += sizeof(struct erofs_dirent);
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}
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return 0;
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}
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static int erofs_readdir(struct file *f, struct dir_context *ctx)
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{
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struct inode *dir = file_inode(f);
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struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
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struct super_block *sb = dir->i_sb;
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unsigned long bsz = sb->s_blocksize;
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unsigned int ofs = erofs_blkoff(sb, ctx->pos);
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int err = 0;
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bool initial = true;
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buf.mapping = dir->i_mapping;
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while (ctx->pos < dir->i_size) {
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erofs_off_t dbstart = ctx->pos - ofs;
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struct erofs_dirent *de;
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unsigned int nameoff, maxsize;
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de = erofs_bread(&buf, dbstart, EROFS_KMAP);
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if (IS_ERR(de)) {
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erofs_err(sb, "fail to readdir of logical block %u of nid %llu",
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erofs_blknr(sb, dbstart), EROFS_I(dir)->nid);
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err = PTR_ERR(de);
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break;
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}
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nameoff = le16_to_cpu(de->nameoff);
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if (nameoff < sizeof(struct erofs_dirent) || nameoff >= bsz) {
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erofs_err(sb, "invalid de[0].nameoff %u @ nid %llu",
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nameoff, EROFS_I(dir)->nid);
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err = -EFSCORRUPTED;
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break;
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}
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maxsize = min_t(unsigned int, dir->i_size - dbstart, bsz);
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/* search dirents at the arbitrary position */
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if (initial) {
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initial = false;
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ofs = roundup(ofs, sizeof(struct erofs_dirent));
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ctx->pos = dbstart + ofs;
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}
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err = erofs_fill_dentries(dir, ctx, de, (void *)de + ofs,
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nameoff, maxsize);
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if (err)
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break;
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ctx->pos = dbstart + maxsize;
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ofs = 0;
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}
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erofs_put_metabuf(&buf);
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return err < 0 ? err : 0;
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}
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const struct file_operations erofs_dir_fops = {
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.llseek = generic_file_llseek,
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.read = generic_read_dir,
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.iterate_shared = erofs_readdir,
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};
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