xref: /openbmc/linux/fs/ext4/symlink.c (revision 6c33a6f4)
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 const struct inode_operations ext4_encrypted_symlink_inode_operations = {
56 	.get_link	= ext4_encrypted_get_link,
57 	.setattr	= ext4_setattr,
58 	.getattr	= ext4_getattr,
59 	.listxattr	= ext4_listxattr,
60 };
61 
62 const struct inode_operations ext4_symlink_inode_operations = {
63 	.get_link	= page_get_link,
64 	.setattr	= ext4_setattr,
65 	.getattr	= ext4_getattr,
66 	.listxattr	= ext4_listxattr,
67 };
68 
69 const struct inode_operations ext4_fast_symlink_inode_operations = {
70 	.get_link	= simple_get_link,
71 	.setattr	= ext4_setattr,
72 	.getattr	= ext4_getattr,
73 	.listxattr	= ext4_listxattr,
74 };
75