GNU Linux-libre 4.19.211-gnu1
[releases.git] / fs / ext4 / symlink.c
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
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
55 static 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
64 const 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
71 const 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
78 const 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 };