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
ext4_encrypted_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)26 static 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
ext4_encrypted_symlink_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)55 static int ext4_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
56 const struct path *path,
57 struct kstat *stat, u32 request_mask,
58 unsigned int query_flags)
59 {
60 ext4_getattr(mnt_userns, path, stat, request_mask, query_flags);
61
62 return fscrypt_symlink_getattr(path, stat);
63 }
64
65 const struct inode_operations ext4_encrypted_symlink_inode_operations = {
66 .get_link = ext4_encrypted_get_link,
67 .setattr = ext4_setattr,
68 .getattr = ext4_encrypted_symlink_getattr,
69 .listxattr = ext4_listxattr,
70 };
71
72 const struct inode_operations ext4_symlink_inode_operations = {
73 .get_link = page_get_link,
74 .setattr = ext4_setattr,
75 .getattr = ext4_getattr,
76 .listxattr = ext4_listxattr,
77 };
78
79 const struct inode_operations ext4_fast_symlink_inode_operations = {
80 .get_link = simple_get_link,
81 .setattr = ext4_setattr,
82 .getattr = ext4_getattr,
83 .listxattr = ext4_listxattr,
84 };
85