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1/*
2 * Copyright (c) 2008, Christoph Hellwig
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_format.h"
20#include "xfs_log_format.h"
21#include "xfs_trans_resv.h"
22#include "xfs_ag.h"
23#include "xfs_sb.h"
24#include "xfs_mount.h"
25#include "xfs_inode.h"
26#include "xfs_acl.h"
27#include "xfs_attr.h"
28#include "xfs_trace.h"
29#include <linux/slab.h>
30#include <linux/xattr.h>
31#include <linux/posix_acl_xattr.h>
32
33
34/*
35 * Locking scheme:
36 * - all ACL updates are protected by inode->i_mutex, which is taken before
37 * calling into this file.
38 */
39
40STATIC struct posix_acl *
41xfs_acl_from_disk(
42 struct xfs_acl *aclp,
43 int max_entries)
44{
45 struct posix_acl_entry *acl_e;
46 struct posix_acl *acl;
47 struct xfs_acl_entry *ace;
48 unsigned int count, i;
49
50 count = be32_to_cpu(aclp->acl_cnt);
51 if (count > max_entries)
52 return ERR_PTR(-EFSCORRUPTED);
53
54 acl = posix_acl_alloc(count, GFP_KERNEL);
55 if (!acl)
56 return ERR_PTR(-ENOMEM);
57
58 for (i = 0; i < count; i++) {
59 acl_e = &acl->a_entries[i];
60 ace = &aclp->acl_entry[i];
61
62 /*
63 * The tag is 32 bits on disk and 16 bits in core.
64 *
65 * Because every access to it goes through the core
66 * format first this is not a problem.
67 */
68 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
69 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
70
71 switch (acl_e->e_tag) {
72 case ACL_USER:
73 acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
74 break;
75 case ACL_GROUP:
76 acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
77 break;
78 case ACL_USER_OBJ:
79 case ACL_GROUP_OBJ:
80 case ACL_MASK:
81 case ACL_OTHER:
82 break;
83 default:
84 goto fail;
85 }
86 }
87 return acl;
88
89fail:
90 posix_acl_release(acl);
91 return ERR_PTR(-EINVAL);
92}
93
94STATIC void
95xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
96{
97 const struct posix_acl_entry *acl_e;
98 struct xfs_acl_entry *ace;
99 int i;
100
101 aclp->acl_cnt = cpu_to_be32(acl->a_count);
102 for (i = 0; i < acl->a_count; i++) {
103 ace = &aclp->acl_entry[i];
104 acl_e = &acl->a_entries[i];
105
106 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
107 switch (acl_e->e_tag) {
108 case ACL_USER:
109 ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
110 break;
111 case ACL_GROUP:
112 ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
113 break;
114 default:
115 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
116 break;
117 }
118
119 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
120 }
121}
122
123struct posix_acl *
124xfs_get_acl(struct inode *inode, int type)
125{
126 struct xfs_inode *ip = XFS_I(inode);
127 struct posix_acl *acl = NULL;
128 struct xfs_acl *xfs_acl;
129 unsigned char *ea_name;
130 int error;
131 int len;
132
133 trace_xfs_get_acl(ip);
134
135 switch (type) {
136 case ACL_TYPE_ACCESS:
137 ea_name = SGI_ACL_FILE;
138 break;
139 case ACL_TYPE_DEFAULT:
140 ea_name = SGI_ACL_DEFAULT;
141 break;
142 default:
143 BUG();
144 }
145
146 /*
147 * If we have a cached ACLs value just return it, not need to
148 * go out to the disk.
149 */
150 len = XFS_ACL_MAX_SIZE(ip->i_mount);
151 xfs_acl = kmem_zalloc_large(len, KM_SLEEP);
152 if (!xfs_acl)
153 return ERR_PTR(-ENOMEM);
154
155 error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
156 &len, ATTR_ROOT);
157 if (error) {
158 /*
159 * If the attribute doesn't exist make sure we have a negative
160 * cache entry, for any other error assume it is transient and
161 * leave the cache entry as ACL_NOT_CACHED.
162 */
163 if (error == -ENOATTR)
164 goto out_update_cache;
165 goto out;
166 }
167
168 acl = xfs_acl_from_disk(xfs_acl, XFS_ACL_MAX_ENTRIES(ip->i_mount));
169 if (IS_ERR(acl))
170 goto out;
171
172out_update_cache:
173 set_cached_acl(inode, type, acl);
174out:
175 kmem_free(xfs_acl);
176 return acl;
177}
178
179STATIC int
180__xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
181{
182 struct xfs_inode *ip = XFS_I(inode);
183 unsigned char *ea_name;
184 int error;
185
186 switch (type) {
187 case ACL_TYPE_ACCESS:
188 ea_name = SGI_ACL_FILE;
189 break;
190 case ACL_TYPE_DEFAULT:
191 if (!S_ISDIR(inode->i_mode))
192 return acl ? -EACCES : 0;
193 ea_name = SGI_ACL_DEFAULT;
194 break;
195 default:
196 return -EINVAL;
197 }
198
199 if (acl) {
200 struct xfs_acl *xfs_acl;
201 int len = XFS_ACL_MAX_SIZE(ip->i_mount);
202
203 xfs_acl = kmem_zalloc_large(len, KM_SLEEP);
204 if (!xfs_acl)
205 return -ENOMEM;
206
207 xfs_acl_to_disk(xfs_acl, acl);
208
209 /* subtract away the unused acl entries */
210 len -= sizeof(struct xfs_acl_entry) *
211 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
212
213 error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
214 len, ATTR_ROOT);
215
216 kmem_free(xfs_acl);
217 } else {
218 /*
219 * A NULL ACL argument means we want to remove the ACL.
220 */
221 error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
222
223 /*
224 * If the attribute didn't exist to start with that's fine.
225 */
226 if (error == -ENOATTR)
227 error = 0;
228 }
229
230 if (!error)
231 set_cached_acl(inode, type, acl);
232 return error;
233}
234
235static int
236xfs_set_mode(struct inode *inode, umode_t mode)
237{
238 int error = 0;
239
240 if (mode != inode->i_mode) {
241 struct iattr iattr;
242
243 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
244 iattr.ia_mode = mode;
245 iattr.ia_ctime = current_fs_time(inode->i_sb);
246
247 error = -xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
248 }
249
250 return error;
251}
252
253static int
254xfs_acl_exists(struct inode *inode, unsigned char *name)
255{
256 int len = XFS_ACL_MAX_SIZE(XFS_M(inode->i_sb));
257
258 return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
259 ATTR_ROOT|ATTR_KERNOVAL) == 0);
260}
261
262int
263posix_acl_access_exists(struct inode *inode)
264{
265 return xfs_acl_exists(inode, SGI_ACL_FILE);
266}
267
268int
269posix_acl_default_exists(struct inode *inode)
270{
271 if (!S_ISDIR(inode->i_mode))
272 return 0;
273 return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
274}
275
276int
277xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
278{
279 int error = 0;
280
281 if (!acl)
282 goto set_acl;
283
284 error = -E2BIG;
285 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
286 return error;
287
288 if (type == ACL_TYPE_ACCESS) {
289 umode_t mode = inode->i_mode;
290 error = posix_acl_equiv_mode(acl, &mode);
291
292 if (error <= 0) {
293 acl = NULL;
294
295 if (error < 0)
296 return error;
297 }
298
299 error = xfs_set_mode(inode, mode);
300 if (error)
301 return error;
302 }
303
304 set_acl:
305 return __xfs_set_acl(inode, type, acl);
306}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2008, Christoph Hellwig
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_shared.h"
8#include "xfs_format.h"
9#include "xfs_log_format.h"
10#include "xfs_trans_resv.h"
11#include "xfs_mount.h"
12#include "xfs_inode.h"
13#include "xfs_attr.h"
14#include "xfs_trace.h"
15#include "xfs_error.h"
16#include "xfs_acl.h"
17#include "xfs_da_format.h"
18#include "xfs_da_btree.h"
19#include "xfs_trans.h"
20
21#include <linux/posix_acl_xattr.h>
22
23/*
24 * Locking scheme:
25 * - all ACL updates are protected by inode->i_mutex, which is taken before
26 * calling into this file.
27 */
28
29STATIC struct posix_acl *
30xfs_acl_from_disk(
31 struct xfs_mount *mp,
32 const struct xfs_acl *aclp,
33 int len,
34 int max_entries)
35{
36 struct posix_acl_entry *acl_e;
37 struct posix_acl *acl;
38 const struct xfs_acl_entry *ace;
39 unsigned int count, i;
40
41 if (len < sizeof(*aclp)) {
42 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
43 len);
44 return ERR_PTR(-EFSCORRUPTED);
45 }
46
47 count = be32_to_cpu(aclp->acl_cnt);
48 if (count > max_entries || XFS_ACL_SIZE(count) != len) {
49 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
50 len);
51 return ERR_PTR(-EFSCORRUPTED);
52 }
53
54 acl = posix_acl_alloc(count, GFP_KERNEL);
55 if (!acl)
56 return ERR_PTR(-ENOMEM);
57
58 for (i = 0; i < count; i++) {
59 acl_e = &acl->a_entries[i];
60 ace = &aclp->acl_entry[i];
61
62 /*
63 * The tag is 32 bits on disk and 16 bits in core.
64 *
65 * Because every access to it goes through the core
66 * format first this is not a problem.
67 */
68 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
69 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
70
71 switch (acl_e->e_tag) {
72 case ACL_USER:
73 acl_e->e_uid = make_kuid(&init_user_ns,
74 be32_to_cpu(ace->ae_id));
75 break;
76 case ACL_GROUP:
77 acl_e->e_gid = make_kgid(&init_user_ns,
78 be32_to_cpu(ace->ae_id));
79 break;
80 case ACL_USER_OBJ:
81 case ACL_GROUP_OBJ:
82 case ACL_MASK:
83 case ACL_OTHER:
84 break;
85 default:
86 goto fail;
87 }
88 }
89 return acl;
90
91fail:
92 posix_acl_release(acl);
93 return ERR_PTR(-EINVAL);
94}
95
96STATIC void
97xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
98{
99 const struct posix_acl_entry *acl_e;
100 struct xfs_acl_entry *ace;
101 int i;
102
103 aclp->acl_cnt = cpu_to_be32(acl->a_count);
104 for (i = 0; i < acl->a_count; i++) {
105 ace = &aclp->acl_entry[i];
106 acl_e = &acl->a_entries[i];
107
108 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
109 switch (acl_e->e_tag) {
110 case ACL_USER:
111 ace->ae_id = cpu_to_be32(
112 from_kuid(&init_user_ns, acl_e->e_uid));
113 break;
114 case ACL_GROUP:
115 ace->ae_id = cpu_to_be32(
116 from_kgid(&init_user_ns, acl_e->e_gid));
117 break;
118 default:
119 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
120 break;
121 }
122
123 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
124 }
125}
126
127struct posix_acl *
128xfs_get_acl(struct inode *inode, int type)
129{
130 struct xfs_inode *ip = XFS_I(inode);
131 struct xfs_mount *mp = ip->i_mount;
132 struct posix_acl *acl = NULL;
133 struct xfs_da_args args = {
134 .dp = ip,
135 .attr_filter = XFS_ATTR_ROOT,
136 .valuelen = XFS_ACL_MAX_SIZE(mp),
137 };
138 int error;
139
140 trace_xfs_get_acl(ip);
141
142 switch (type) {
143 case ACL_TYPE_ACCESS:
144 args.name = SGI_ACL_FILE;
145 break;
146 case ACL_TYPE_DEFAULT:
147 args.name = SGI_ACL_DEFAULT;
148 break;
149 default:
150 BUG();
151 }
152 args.namelen = strlen(args.name);
153
154 /*
155 * If the attribute doesn't exist make sure we have a negative cache
156 * entry, for any other error assume it is transient.
157 */
158 error = xfs_attr_get(&args);
159 if (!error) {
160 acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
161 XFS_ACL_MAX_ENTRIES(mp));
162 } else if (error != -ENOATTR) {
163 acl = ERR_PTR(error);
164 }
165
166 kmem_free(args.value);
167 return acl;
168}
169
170int
171__xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
172{
173 struct xfs_inode *ip = XFS_I(inode);
174 struct xfs_da_args args = {
175 .dp = ip,
176 .attr_filter = XFS_ATTR_ROOT,
177 };
178 int error;
179
180 switch (type) {
181 case ACL_TYPE_ACCESS:
182 args.name = SGI_ACL_FILE;
183 break;
184 case ACL_TYPE_DEFAULT:
185 if (!S_ISDIR(inode->i_mode))
186 return acl ? -EACCES : 0;
187 args.name = SGI_ACL_DEFAULT;
188 break;
189 default:
190 return -EINVAL;
191 }
192 args.namelen = strlen(args.name);
193
194 if (acl) {
195 args.valuelen = XFS_ACL_SIZE(acl->a_count);
196 args.value = kvzalloc(args.valuelen, GFP_KERNEL);
197 if (!args.value)
198 return -ENOMEM;
199 xfs_acl_to_disk(args.value, acl);
200 }
201
202 error = xfs_attr_set(&args);
203 kmem_free(args.value);
204
205 /*
206 * If the attribute didn't exist to start with that's fine.
207 */
208 if (!acl && error == -ENOATTR)
209 error = 0;
210 if (!error)
211 set_cached_acl(inode, type, acl);
212 return error;
213}
214
215static int
216xfs_acl_set_mode(
217 struct inode *inode,
218 umode_t mode)
219{
220 struct xfs_inode *ip = XFS_I(inode);
221 struct xfs_mount *mp = ip->i_mount;
222 struct xfs_trans *tp;
223 int error;
224
225 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
226 if (error)
227 return error;
228
229 xfs_ilock(ip, XFS_ILOCK_EXCL);
230 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
231 inode->i_mode = mode;
232 inode->i_ctime = current_time(inode);
233 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
234
235 if (mp->m_flags & XFS_MOUNT_WSYNC)
236 xfs_trans_set_sync(tp);
237 return xfs_trans_commit(tp);
238}
239
240int
241xfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
242 struct posix_acl *acl, int type)
243{
244 umode_t mode;
245 bool set_mode = false;
246 int error = 0;
247
248 if (!acl)
249 goto set_acl;
250
251 error = -E2BIG;
252 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
253 return error;
254
255 if (type == ACL_TYPE_ACCESS) {
256 error = posix_acl_update_mode(mnt_userns, inode, &mode, &acl);
257 if (error)
258 return error;
259 set_mode = true;
260 }
261
262 set_acl:
263 /*
264 * We set the mode after successfully updating the ACL xattr because the
265 * xattr update can fail at ENOSPC and we don't want to change the mode
266 * if the ACL update hasn't been applied.
267 */
268 error = __xfs_set_acl(inode, acl, type);
269 if (!error && set_mode && mode != inode->i_mode)
270 error = xfs_acl_set_mode(inode, mode);
271 return error;
272}
273
274/*
275 * Invalidate any cached ACLs if the user has bypassed the ACL interface.
276 * We don't validate the content whatsoever so it is caller responsibility to
277 * provide data in valid format and ensure i_mode is consistent.
278 */
279void
280xfs_forget_acl(
281 struct inode *inode,
282 const char *name)
283{
284 if (!strcmp(name, SGI_ACL_FILE))
285 forget_cached_acl(inode, ACL_TYPE_ACCESS);
286 else if (!strcmp(name, SGI_ACL_DEFAULT))
287 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
288}