Commit | Line | Data |
---|---|---|
ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/symlink.c |
ac27a0ec DK |
3 | * |
4 | * Only fast symlinks left here - the rest is done by generic code. AV, 1999 | |
5 | * | |
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) | |
10 | * | |
11 | * from | |
12 | * | |
13 | * linux/fs/minix/symlink.c | |
14 | * | |
15 | * Copyright (C) 1991, 1992 Linus Torvalds | |
16 | * | |
617ba13b | 17 | * ext4 symlink handling code |
ac27a0ec DK |
18 | */ |
19 | ||
20 | #include <linux/fs.h> | |
ac27a0ec | 21 | #include <linux/namei.h> |
3dcf5451 | 22 | #include "ext4.h" |
ac27a0ec DK |
23 | #include "xattr.h" |
24 | ||
f348c252 | 25 | #ifdef CONFIG_EXT4_FS_ENCRYPTION |
6b255391 AV |
26 | static const char *ext4_encrypted_get_link(struct dentry *dentry, |
27 | struct inode *inode, void **cookie) | |
f348c252 TT |
28 | { |
29 | struct page *cpage = NULL; | |
30 | char *caddr, *paddr = NULL; | |
31 | struct ext4_str cstr, pstr; | |
f348c252 TT |
32 | struct ext4_encrypted_symlink_data *sd; |
33 | loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1); | |
34 | int res; | |
35 | u32 plen, max_size = inode->i_sb->s_blocksize; | |
36 | ||
6b255391 AV |
37 | if (!dentry) |
38 | return ERR_PTR(-ECHILD); | |
39 | ||
c936e1ec | 40 | res = ext4_get_encryption_info(inode); |
b7236e21 TT |
41 | if (res) |
42 | return ERR_PTR(res); | |
f348c252 TT |
43 | |
44 | if (ext4_inode_is_fast_symlink(inode)) { | |
9ec3a646 LT |
45 | caddr = (char *) EXT4_I(inode)->i_data; |
46 | max_size = sizeof(EXT4_I(inode)->i_data); | |
f348c252 TT |
47 | } else { |
48 | cpage = read_mapping_page(inode->i_mapping, 0, NULL); | |
b7236e21 | 49 | if (IS_ERR(cpage)) |
680baacb | 50 | return ERR_CAST(cpage); |
21fc61c7 | 51 | caddr = page_address(cpage); |
f348c252 TT |
52 | caddr[size] = 0; |
53 | } | |
54 | ||
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); | |
59 | if ((cstr.len + | |
60 | sizeof(struct ext4_encrypted_symlink_data) - 1) > | |
61 | max_size) { | |
62 | /* Symlink data on the disk is corrupted */ | |
6a797d27 | 63 | res = -EFSCORRUPTED; |
f348c252 TT |
64 | goto errout; |
65 | } | |
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); | |
69 | if (!paddr) { | |
70 | res = -ENOMEM; | |
71 | goto errout; | |
72 | } | |
73 | pstr.name = paddr; | |
d2299590 | 74 | pstr.len = plen; |
b7236e21 | 75 | res = _ext4_fname_disk_to_usr(inode, NULL, &cstr, &pstr); |
f348c252 TT |
76 | if (res < 0) |
77 | goto errout; | |
78 | /* Null-terminate the name */ | |
79 | if (res <= plen) | |
80 | paddr[res] = '\0'; | |
21fc61c7 | 81 | if (cpage) |
f348c252 | 82 | page_cache_release(cpage); |
680baacb | 83 | return *cookie = paddr; |
f348c252 | 84 | errout: |
21fc61c7 | 85 | if (cpage) |
f348c252 | 86 | page_cache_release(cpage); |
f348c252 TT |
87 | kfree(paddr); |
88 | return ERR_PTR(res); | |
89 | } | |
90 | ||
a7a67e8a AV |
91 | const struct inode_operations ext4_encrypted_symlink_inode_operations = { |
92 | .readlink = generic_readlink, | |
6b255391 | 93 | .get_link = ext4_encrypted_get_link, |
a7a67e8a AV |
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, | |
100 | }; | |
f348c252 TT |
101 | #endif |
102 | ||
754661f1 | 103 | const struct inode_operations ext4_symlink_inode_operations = { |
ac27a0ec | 104 | .readlink = generic_readlink, |
6b255391 | 105 | .get_link = page_get_link, |
ac27a0ec | 106 | .put_link = page_put_link, |
256a4535 | 107 | .setattr = ext4_setattr, |
ac27a0ec DK |
108 | .setxattr = generic_setxattr, |
109 | .getxattr = generic_getxattr, | |
617ba13b | 110 | .listxattr = ext4_listxattr, |
ac27a0ec | 111 | .removexattr = generic_removexattr, |
ac27a0ec DK |
112 | }; |
113 | ||
754661f1 | 114 | const struct inode_operations ext4_fast_symlink_inode_operations = { |
ac27a0ec | 115 | .readlink = generic_readlink, |
6b255391 | 116 | .get_link = simple_get_link, |
256a4535 | 117 | .setattr = ext4_setattr, |
ac27a0ec DK |
118 | .setxattr = generic_setxattr, |
119 | .getxattr = generic_getxattr, | |
617ba13b | 120 | .listxattr = ext4_listxattr, |
ac27a0ec | 121 | .removexattr = generic_removexattr, |
ac27a0ec | 122 | }; |