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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/*
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_mount.h"
23#include "xfs_inode.h"
24#include "xfs_acl.h"
25#include "xfs_attr.h"
26#include "xfs_trace.h"
27#include <linux/slab.h>
28#include <linux/xattr.h>
29#include <linux/posix_acl_xattr.h>
30
31
32/*
33 * Locking scheme:
34 * - all ACL updates are protected by inode->i_mutex, which is taken before
35 * calling into this file.
36 */
37
38STATIC struct posix_acl *
39xfs_acl_from_disk(
40 const struct xfs_acl *aclp,
41 int len,
42 int max_entries)
43{
44 struct posix_acl_entry *acl_e;
45 struct posix_acl *acl;
46 const struct xfs_acl_entry *ace;
47 unsigned int count, i;
48
49 if (len < sizeof(*aclp))
50 return ERR_PTR(-EFSCORRUPTED);
51 count = be32_to_cpu(aclp->acl_cnt);
52 if (count > max_entries || XFS_ACL_SIZE(count) != len)
53 return ERR_PTR(-EFSCORRUPTED);
54
55 acl = posix_acl_alloc(count, GFP_KERNEL);
56 if (!acl)
57 return ERR_PTR(-ENOMEM);
58
59 for (i = 0; i < count; i++) {
60 acl_e = &acl->a_entries[i];
61 ace = &aclp->acl_entry[i];
62
63 /*
64 * The tag is 32 bits on disk and 16 bits in core.
65 *
66 * Because every access to it goes through the core
67 * format first this is not a problem.
68 */
69 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
70 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
71
72 switch (acl_e->e_tag) {
73 case ACL_USER:
74 acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
75 break;
76 case ACL_GROUP:
77 acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
78 break;
79 case ACL_USER_OBJ:
80 case ACL_GROUP_OBJ:
81 case ACL_MASK:
82 case ACL_OTHER:
83 break;
84 default:
85 goto fail;
86 }
87 }
88 return acl;
89
90fail:
91 posix_acl_release(acl);
92 return ERR_PTR(-EINVAL);
93}
94
95STATIC void
96xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
97{
98 const struct posix_acl_entry *acl_e;
99 struct xfs_acl_entry *ace;
100 int i;
101
102 aclp->acl_cnt = cpu_to_be32(acl->a_count);
103 for (i = 0; i < acl->a_count; i++) {
104 ace = &aclp->acl_entry[i];
105 acl_e = &acl->a_entries[i];
106
107 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
108 switch (acl_e->e_tag) {
109 case ACL_USER:
110 ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
111 break;
112 case ACL_GROUP:
113 ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
114 break;
115 default:
116 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
117 break;
118 }
119
120 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
121 }
122}
123
124struct posix_acl *
125xfs_get_acl(struct inode *inode, int type)
126{
127 struct xfs_inode *ip = XFS_I(inode);
128 struct posix_acl *acl = NULL;
129 struct xfs_acl *xfs_acl;
130 unsigned char *ea_name;
131 int error;
132 int len;
133
134 trace_xfs_get_acl(ip);
135
136 switch (type) {
137 case ACL_TYPE_ACCESS:
138 ea_name = SGI_ACL_FILE;
139 break;
140 case ACL_TYPE_DEFAULT:
141 ea_name = SGI_ACL_DEFAULT;
142 break;
143 default:
144 BUG();
145 }
146
147 /*
148 * If we have a cached ACLs value just return it, not need to
149 * go out to the disk.
150 */
151 len = XFS_ACL_MAX_SIZE(ip->i_mount);
152 xfs_acl = kmem_zalloc_large(len, KM_SLEEP);
153 if (!xfs_acl)
154 return ERR_PTR(-ENOMEM);
155
156 error = xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
157 &len, ATTR_ROOT);
158 if (error) {
159 /*
160 * If the attribute doesn't exist make sure we have a negative
161 * cache entry, for any other error assume it is transient and
162 * leave the cache entry as ACL_NOT_CACHED.
163 */
164 if (error == -ENOATTR)
165 goto out_update_cache;
166 acl = ERR_PTR(error);
167 goto out;
168 }
169
170 acl = xfs_acl_from_disk(xfs_acl, len, XFS_ACL_MAX_ENTRIES(ip->i_mount));
171 if (IS_ERR(acl))
172 goto out;
173
174out_update_cache:
175 set_cached_acl(inode, type, acl);
176out:
177 kmem_free(xfs_acl);
178 return acl;
179}
180
181STATIC int
182__xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
183{
184 struct xfs_inode *ip = XFS_I(inode);
185 unsigned char *ea_name;
186 int error;
187
188 switch (type) {
189 case ACL_TYPE_ACCESS:
190 ea_name = SGI_ACL_FILE;
191 break;
192 case ACL_TYPE_DEFAULT:
193 if (!S_ISDIR(inode->i_mode))
194 return acl ? -EACCES : 0;
195 ea_name = SGI_ACL_DEFAULT;
196 break;
197 default:
198 return -EINVAL;
199 }
200
201 if (acl) {
202 struct xfs_acl *xfs_acl;
203 int len = XFS_ACL_MAX_SIZE(ip->i_mount);
204
205 xfs_acl = kmem_zalloc_large(len, KM_SLEEP);
206 if (!xfs_acl)
207 return -ENOMEM;
208
209 xfs_acl_to_disk(xfs_acl, acl);
210
211 /* subtract away the unused acl entries */
212 len -= sizeof(struct xfs_acl_entry) *
213 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
214
215 error = xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
216 len, ATTR_ROOT);
217
218 kmem_free(xfs_acl);
219 } else {
220 /*
221 * A NULL ACL argument means we want to remove the ACL.
222 */
223 error = xfs_attr_remove(ip, ea_name, ATTR_ROOT);
224
225 /*
226 * If the attribute didn't exist to start with that's fine.
227 */
228 if (error == -ENOATTR)
229 error = 0;
230 }
231
232 if (!error)
233 set_cached_acl(inode, type, acl);
234 return error;
235}
236
237static int
238xfs_set_mode(struct inode *inode, umode_t mode)
239{
240 int error = 0;
241
242 if (mode != inode->i_mode) {
243 struct iattr iattr;
244
245 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
246 iattr.ia_mode = mode;
247 iattr.ia_ctime = current_fs_time(inode->i_sb);
248
249 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
250 }
251
252 return error;
253}
254
255int
256xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
257{
258 int error = 0;
259
260 if (!acl)
261 goto set_acl;
262
263 error = -E2BIG;
264 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
265 return error;
266
267 if (type == ACL_TYPE_ACCESS) {
268 umode_t mode = inode->i_mode;
269 error = posix_acl_equiv_mode(acl, &mode);
270
271 if (error <= 0) {
272 acl = NULL;
273
274 if (error < 0)
275 return error;
276 }
277
278 error = xfs_set_mode(inode, mode);
279 if (error)
280 return error;
281 }
282
283 set_acl:
284 return __xfs_set_acl(inode, type, acl);
285}