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1/*
2 * linux/fs/ext4/symlink.c
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 *
17 * ext4 symlink handling code
18 */
19
20#include <linux/fs.h>
21#include <linux/jbd2.h>
22#include <linux/namei.h>
23#include "ext4.h"
24#include "xattr.h"
25
26static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
27{
28 struct ext4_inode_info *ei = EXT4_I(dentry->d_inode);
29 nd_set_link(nd, (char *) ei->i_data);
30 return NULL;
31}
32
33const struct inode_operations ext4_symlink_inode_operations = {
34 .readlink = generic_readlink,
35 .follow_link = page_follow_link_light,
36 .put_link = page_put_link,
37 .setattr = ext4_setattr,
38#ifdef CONFIG_EXT4_FS_XATTR
39 .setxattr = generic_setxattr,
40 .getxattr = generic_getxattr,
41 .listxattr = ext4_listxattr,
42 .removexattr = generic_removexattr,
43#endif
44};
45
46const struct inode_operations ext4_fast_symlink_inode_operations = {
47 .readlink = generic_readlink,
48 .follow_link = ext4_follow_link,
49 .setattr = ext4_setattr,
50#ifdef CONFIG_EXT4_FS_XATTR
51 .setxattr = generic_setxattr,
52 .getxattr = generic_getxattr,
53 .listxattr = ext4_listxattr,
54 .removexattr = generic_removexattr,
55#endif
56};
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
26static const char *ext4_encrypted_get_link(struct dentry *dentry,
27 struct inode *inode,
28 struct delayed_call *done)
29{
30 struct buffer_head *bh = 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 bh = ext4_bread(NULL, inode, 0, 0);
43 if (IS_ERR(bh))
44 return ERR_CAST(bh);
45 if (!bh) {
46 EXT4_ERROR_INODE(inode, "bad symlink.");
47 return ERR_PTR(-EFSCORRUPTED);
48 }
49 caddr = bh->b_data;
50 max_size = inode->i_sb->s_blocksize;
51 }
52
53 paddr = fscrypt_get_symlink(inode, caddr, max_size, done);
54 brelse(bh);
55 return paddr;
56}
57
58static int ext4_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
59 const struct path *path,
60 struct kstat *stat, u32 request_mask,
61 unsigned int query_flags)
62{
63 ext4_getattr(mnt_userns, path, stat, request_mask, query_flags);
64
65 return fscrypt_symlink_getattr(path, stat);
66}
67
68static void ext4_free_link(void *bh)
69{
70 brelse(bh);
71}
72
73static const char *ext4_get_link(struct dentry *dentry, struct inode *inode,
74 struct delayed_call *callback)
75{
76 struct buffer_head *bh;
77 char *inline_link;
78
79 /*
80 * Create a new inlined symlink is not supported, just provide a
81 * method to read the leftovers.
82 */
83 if (ext4_has_inline_data(inode)) {
84 if (!dentry)
85 return ERR_PTR(-ECHILD);
86
87 inline_link = ext4_read_inline_link(inode);
88 if (!IS_ERR(inline_link))
89 set_delayed_call(callback, kfree_link, inline_link);
90 return inline_link;
91 }
92
93 if (!dentry) {
94 bh = ext4_getblk(NULL, inode, 0, EXT4_GET_BLOCKS_CACHED_NOWAIT);
95 if (IS_ERR(bh))
96 return ERR_CAST(bh);
97 if (!bh || !ext4_buffer_uptodate(bh))
98 return ERR_PTR(-ECHILD);
99 } else {
100 bh = ext4_bread(NULL, inode, 0, 0);
101 if (IS_ERR(bh))
102 return ERR_CAST(bh);
103 if (!bh) {
104 EXT4_ERROR_INODE(inode, "bad symlink.");
105 return ERR_PTR(-EFSCORRUPTED);
106 }
107 }
108
109 set_delayed_call(callback, ext4_free_link, bh);
110 nd_terminate_link(bh->b_data, inode->i_size,
111 inode->i_sb->s_blocksize - 1);
112 return bh->b_data;
113}
114
115const struct inode_operations ext4_encrypted_symlink_inode_operations = {
116 .get_link = ext4_encrypted_get_link,
117 .setattr = ext4_setattr,
118 .getattr = ext4_encrypted_symlink_getattr,
119 .listxattr = ext4_listxattr,
120};
121
122const struct inode_operations ext4_symlink_inode_operations = {
123 .get_link = ext4_get_link,
124 .setattr = ext4_setattr,
125 .getattr = ext4_getattr,
126 .listxattr = ext4_listxattr,
127};
128
129const struct inode_operations ext4_fast_symlink_inode_operations = {
130 .get_link = simple_get_link,
131 .setattr = ext4_setattr,
132 .getattr = ext4_getattr,
133 .listxattr = ext4_listxattr,
134};