xref: /kernel/linux/linux-5.10/fs/ext4/symlink.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  linux/fs/ext4/symlink.c
4 *
5 * Only fast symlinks left here - the rest is done by generic code. AV, 1999
6 *
7 * Copyright (C) 1992, 1993, 1994, 1995
8 * Remy Card (card@masi.ibp.fr)
9 * Laboratoire MASI - Institut Blaise Pascal
10 * Universite Pierre et Marie Curie (Paris VI)
11 *
12 *  from
13 *
14 *  linux/fs/minix/symlink.c
15 *
16 *  Copyright (C) 1991, 1992  Linus Torvalds
17 *
18 *  ext4 symlink handling code
19 */
20
21#include <linux/fs.h>
22#include <linux/namei.h>
23#include "ext4.h"
24#include "xattr.h"
25
26static const char *ext4_encrypted_get_link(struct dentry *dentry,
27					   struct inode *inode,
28					   struct delayed_call *done)
29{
30	struct page *cpage = NULL;
31	const void *caddr;
32	unsigned int max_size;
33	const char *paddr;
34
35	if (!dentry)
36		return ERR_PTR(-ECHILD);
37
38	if (ext4_inode_is_fast_symlink(inode)) {
39		caddr = EXT4_I(inode)->i_data;
40		max_size = sizeof(EXT4_I(inode)->i_data);
41	} else {
42		cpage = read_mapping_page(inode->i_mapping, 0, NULL);
43		if (IS_ERR(cpage))
44			return ERR_CAST(cpage);
45		caddr = page_address(cpage);
46		max_size = inode->i_sb->s_blocksize;
47	}
48
49	paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
50	if (cpage)
51		put_page(cpage);
52	return paddr;
53}
54
55static int ext4_encrypted_symlink_getattr(const struct path *path,
56					  struct kstat *stat, u32 request_mask,
57					  unsigned int query_flags)
58{
59	ext4_getattr(path, stat, request_mask, query_flags);
60
61	return fscrypt_symlink_getattr(path, stat);
62}
63
64const struct inode_operations ext4_encrypted_symlink_inode_operations = {
65	.get_link	= ext4_encrypted_get_link,
66	.setattr	= ext4_setattr,
67	.getattr	= ext4_encrypted_symlink_getattr,
68	.listxattr	= ext4_listxattr,
69};
70
71const struct inode_operations ext4_symlink_inode_operations = {
72	.get_link	= page_get_link,
73	.setattr	= ext4_setattr,
74	.getattr	= ext4_getattr,
75	.listxattr	= ext4_listxattr,
76};
77
78const struct inode_operations ext4_fast_symlink_inode_operations = {
79	.get_link	= simple_get_link,
80	.setattr	= ext4_setattr,
81	.getattr	= ext4_getattr,
82	.listxattr	= ext4_listxattr,
83};
84