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Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 * linux/fs/ext4/acl.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003 *
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
5 */
6
Christoph Hellwig3dcf5452008-04-29 18:13:32 -04007#include "ext4_jbd2.h"
8#include "ext4.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -07009#include "xattr.h"
10#include "acl.h"
11
12/*
13 * Convert from filesystem to in-memory representation.
14 */
15static struct posix_acl *
Mingming Cao617ba132006-10-11 01:20:53 -070016ext4_acl_from_disk(const void *value, size_t size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070017{
18 const char *end = (char *)value + size;
19 int n, count;
20 struct posix_acl *acl;
21
22 if (!value)
23 return NULL;
Mingming Cao617ba132006-10-11 01:20:53 -070024 if (size < sizeof(ext4_acl_header))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070025 return ERR_PTR(-EINVAL);
Mingming Cao617ba132006-10-11 01:20:53 -070026 if (((ext4_acl_header *)value)->a_version !=
27 cpu_to_le32(EXT4_ACL_VERSION))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070028 return ERR_PTR(-EINVAL);
Mingming Cao617ba132006-10-11 01:20:53 -070029 value = (char *)value + sizeof(ext4_acl_header);
30 count = ext4_acl_count(size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070031 if (count < 0)
32 return ERR_PTR(-EINVAL);
33 if (count == 0)
34 return NULL;
Josef Bacik216553c2008-04-29 22:02:02 -040035 acl = posix_acl_alloc(count, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070036 if (!acl)
37 return ERR_PTR(-ENOMEM);
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -040038 for (n = 0; n < count; n++) {
Mingming Cao617ba132006-10-11 01:20:53 -070039 ext4_acl_entry *entry =
40 (ext4_acl_entry *)value;
41 if ((char *)value + sizeof(ext4_acl_entry_short) > end)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070042 goto fail;
43 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
44 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070045
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -040046 switch (acl->a_entries[n].e_tag) {
47 case ACL_USER_OBJ:
48 case ACL_GROUP_OBJ:
49 case ACL_MASK:
50 case ACL_OTHER:
51 value = (char *)value +
52 sizeof(ext4_acl_entry_short);
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -040053 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070054
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -040055 case ACL_USER:
Eric W. Biedermanaf84df92012-09-10 20:44:54 -070056 value = (char *)value + sizeof(ext4_acl_entry);
57 if ((char *)value > end)
58 goto fail;
59 acl->a_entries[n].e_uid =
60 make_kuid(&init_user_ns,
61 le32_to_cpu(entry->e_id));
62 break;
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -040063 case ACL_GROUP:
64 value = (char *)value + sizeof(ext4_acl_entry);
65 if ((char *)value > end)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070066 goto fail;
Eric W. Biedermanaf84df92012-09-10 20:44:54 -070067 acl->a_entries[n].e_gid =
68 make_kgid(&init_user_ns,
69 le32_to_cpu(entry->e_id));
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -040070 break;
71
72 default:
73 goto fail;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070074 }
75 }
76 if (value != end)
77 goto fail;
78 return acl;
79
80fail:
81 posix_acl_release(acl);
82 return ERR_PTR(-EINVAL);
83}
84
85/*
86 * Convert from in-memory to filesystem representation.
87 */
88static void *
Mingming Cao617ba132006-10-11 01:20:53 -070089ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070090{
Mingming Cao617ba132006-10-11 01:20:53 -070091 ext4_acl_header *ext_acl;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070092 char *e;
93 size_t n;
94
Mingming Cao617ba132006-10-11 01:20:53 -070095 *size = ext4_acl_size(acl->a_count);
96 ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
Josef Bacik216553c2008-04-29 22:02:02 -040097 sizeof(ext4_acl_entry), GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070098 if (!ext_acl)
99 return ERR_PTR(-ENOMEM);
Mingming Cao617ba132006-10-11 01:20:53 -0700100 ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
101 e = (char *)ext_acl + sizeof(ext4_acl_header);
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400102 for (n = 0; n < acl->a_count; n++) {
Eric W. Biedermanaf84df92012-09-10 20:44:54 -0700103 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
Mingming Cao617ba132006-10-11 01:20:53 -0700104 ext4_acl_entry *entry = (ext4_acl_entry *)e;
Eric W. Biedermanaf84df92012-09-10 20:44:54 -0700105 entry->e_tag = cpu_to_le16(acl_e->e_tag);
106 entry->e_perm = cpu_to_le16(acl_e->e_perm);
107 switch (acl_e->e_tag) {
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400108 case ACL_USER:
Eric W. Biedermanaf84df92012-09-10 20:44:54 -0700109 entry->e_id = cpu_to_le32(
110 from_kuid(&init_user_ns, acl_e->e_uid));
111 e += sizeof(ext4_acl_entry);
112 break;
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400113 case ACL_GROUP:
Eric W. Biedermanaf84df92012-09-10 20:44:54 -0700114 entry->e_id = cpu_to_le32(
115 from_kgid(&init_user_ns, acl_e->e_gid));
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400116 e += sizeof(ext4_acl_entry);
117 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700118
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400119 case ACL_USER_OBJ:
120 case ACL_GROUP_OBJ:
121 case ACL_MASK:
122 case ACL_OTHER:
123 e += sizeof(ext4_acl_entry_short);
124 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700125
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400126 default:
127 goto fail;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700128 }
129 }
130 return (char *)ext_acl;
131
132fail:
133 kfree(ext_acl);
134 return ERR_PTR(-EINVAL);
135}
136
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700137/*
138 * Inode operation get_posix_acl().
139 *
140 * inode->i_mutex: don't care
141 */
Christoph Hellwig4e34e712011-07-23 17:37:31 +0200142struct posix_acl *
Mingming Cao617ba132006-10-11 01:20:53 -0700143ext4_get_acl(struct inode *inode, int type)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700144{
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700145 int name_index;
146 char *value = NULL;
147 struct posix_acl *acl;
148 int retval;
149
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400150 switch (type) {
151 case ACL_TYPE_ACCESS:
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400152 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
153 break;
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400154 case ACL_TYPE_DEFAULT:
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400155 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
156 break;
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400157 default:
Al Viro073aaa12009-06-09 12:11:54 -0400158 BUG();
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700159 }
Mingming Cao617ba132006-10-11 01:20:53 -0700160 retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700161 if (retval > 0) {
Josef Bacik216553c2008-04-29 22:02:02 -0400162 value = kmalloc(retval, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700163 if (!value)
164 return ERR_PTR(-ENOMEM);
Mingming Cao617ba132006-10-11 01:20:53 -0700165 retval = ext4_xattr_get(inode, name_index, "", value, retval);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700166 }
167 if (retval > 0)
Mingming Cao617ba132006-10-11 01:20:53 -0700168 acl = ext4_acl_from_disk(value, retval);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700169 else if (retval == -ENODATA || retval == -ENOSYS)
170 acl = NULL;
171 else
172 acl = ERR_PTR(retval);
173 kfree(value);
174
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700175 return acl;
176}
177
178/*
179 * Set the access or default ACL of an inode.
180 *
Mingming Cao617ba132006-10-11 01:20:53 -0700181 * inode->i_mutex: down unless called from ext4_new_inode
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700182 */
183static int
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800184__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700185 struct posix_acl *acl)
186{
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700187 int name_index;
188 void *value = NULL;
189 size_t size = 0;
190 int error;
191
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400192 switch (type) {
193 case ACL_TYPE_ACCESS:
194 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
195 if (acl) {
Jan Kara07393102016-09-19 17:39:09 +0200196 error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
197 if (error)
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400198 return error;
Jan Kara07393102016-09-19 17:39:09 +0200199 inode->i_ctime = ext4_current_time(inode);
200 ext4_mark_inode_dirty(handle, inode);
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400201 }
202 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700203
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400204 case ACL_TYPE_DEFAULT:
205 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
206 if (!S_ISDIR(inode->i_mode))
207 return acl ? -EACCES : 0;
208 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700209
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400210 default:
211 return -EINVAL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700212 }
213 if (acl) {
Mingming Cao617ba132006-10-11 01:20:53 -0700214 value = ext4_acl_to_disk(acl, &size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700215 if (IS_ERR(value))
216 return (int)PTR_ERR(value);
217 }
218
Mingming Cao617ba132006-10-11 01:20:53 -0700219 error = ext4_xattr_set_handle(handle, inode, name_index, "",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700220 value, size, 0);
221
222 kfree(value);
Al Viro073aaa12009-06-09 12:11:54 -0400223 if (!error)
224 set_cached_acl(inode, type, acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700225
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700226 return error;
227}
228
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800229int
230ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
231{
232 handle_t *handle;
233 int error, retries = 0;
234
235retry:
236 handle = ext4_journal_start(inode, EXT4_HT_XATTR,
237 ext4_jbd2_credits_xattr(inode));
238 if (IS_ERR(handle))
239 return PTR_ERR(handle);
240
241 error = __ext4_set_acl(handle, inode, type, acl);
242 ext4_journal_stop(handle);
243 if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
244 goto retry;
245 return error;
246}
247
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700248/*
Mingming Cao617ba132006-10-11 01:20:53 -0700249 * Initialize the ACLs of a new inode. Called from ext4_new_inode.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700250 *
251 * dir->i_mutex: down
252 * inode->i_mutex: up (access to inode is still exclusive)
253 */
254int
Mingming Cao617ba132006-10-11 01:20:53 -0700255ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700256{
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800257 struct posix_acl *default_acl, *acl;
Andrew Morton63f57932006-10-11 01:21:24 -0700258 int error;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700259
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800260 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
Al Virobc26ab52011-07-23 00:18:02 -0400261 if (error)
262 return error;
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800263
264 if (default_acl) {
265 error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
266 default_acl);
267 posix_acl_release(default_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700268 }
Christoph Hellwig64e178a2013-12-20 05:16:44 -0800269 if (acl) {
270 if (!error)
271 error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
272 acl);
273 posix_acl_release(acl);
Eugene Shatokhin24ec19b2012-11-08 15:11:11 -0500274 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700275 return error;
276}