2 * linux/fs/ext4/symlink.c
4 * Only fast symlinks left here - the rest is done by generic code. AV, 1999
6 * Copyright (C) 1992, 1993, 1994, 1995
7 * Remy Card (card@masi.ibp.fr)
8 * Laboratoire MASI - Institut Blaise Pascal
9 * Universite Pierre et Marie Curie (Paris VI)
13 * linux/fs/minix/symlink.c
15 * Copyright (C) 1991, 1992 Linus Torvalds
17 * ext4 symlink handling code
21 #include <linux/namei.h>
25 #ifdef CONFIG_EXT4_FS_ENCRYPTION
26 static const char *ext4_encrypted_get_link(struct dentry *dentry,
27 struct inode *inode, void **cookie)
29 struct page *cpage = NULL;
30 char *caddr, *paddr = NULL;
31 struct ext4_str cstr, pstr;
32 struct ext4_encrypted_symlink_data *sd;
33 loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
35 u32 plen, max_size = inode->i_sb->s_blocksize;
38 return ERR_PTR(-ECHILD);
40 res = ext4_get_encryption_info(inode);
44 if (ext4_inode_is_fast_symlink(inode)) {
45 caddr = (char *) EXT4_I(inode)->i_data;
46 max_size = sizeof(EXT4_I(inode)->i_data);
48 cpage = read_mapping_page(inode->i_mapping, 0, NULL);
50 return ERR_CAST(cpage);
51 caddr = page_address(cpage);
55 /* Symlink is encrypted */
56 sd = (struct ext4_encrypted_symlink_data *)caddr;
57 cstr.name = sd->encrypted_path;
58 cstr.len = le32_to_cpu(sd->len);
60 sizeof(struct ext4_encrypted_symlink_data) - 1) >
62 /* Symlink data on the disk is corrupted */
66 plen = (cstr.len < EXT4_FNAME_CRYPTO_DIGEST_SIZE*2) ?
67 EXT4_FNAME_CRYPTO_DIGEST_SIZE*2 : cstr.len;
68 paddr = kmalloc(plen + 1, GFP_NOFS);
75 res = _ext4_fname_disk_to_usr(inode, NULL, &cstr, &pstr);
78 /* Null-terminate the name */
82 page_cache_release(cpage);
83 return *cookie = paddr;
86 page_cache_release(cpage);
91 const struct inode_operations ext4_encrypted_symlink_inode_operations = {
92 .readlink = generic_readlink,
93 .get_link = ext4_encrypted_get_link,
94 .put_link = kfree_put_link,
95 .setattr = ext4_setattr,
96 .setxattr = generic_setxattr,
97 .getxattr = generic_getxattr,
98 .listxattr = ext4_listxattr,
99 .removexattr = generic_removexattr,
103 const struct inode_operations ext4_symlink_inode_operations = {
104 .readlink = generic_readlink,
105 .get_link = page_get_link,
106 .put_link = page_put_link,
107 .setattr = ext4_setattr,
108 .setxattr = generic_setxattr,
109 .getxattr = generic_getxattr,
110 .listxattr = ext4_listxattr,
111 .removexattr = generic_removexattr,
114 const struct inode_operations ext4_fast_symlink_inode_operations = {
115 .readlink = generic_readlink,
116 .get_link = simple_get_link,
117 .setattr = ext4_setattr,
118 .setxattr = generic_setxattr,
119 .getxattr = generic_getxattr,
120 .listxattr = ext4_listxattr,
121 .removexattr = generic_removexattr,