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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
20#include <linux/posix_acl_xattr.h>
21
22/*
23 * Locking scheme:
24 * - all ACL updates are protected by inode->i_mutex, which is taken before
25 * calling into this file.
26 */
27
28STATIC struct posix_acl *
29xfs_acl_from_disk(
30 struct xfs_mount *mp,
31 const struct xfs_acl *aclp,
32 int len,
33 int max_entries)
34{
35 struct posix_acl_entry *acl_e;
36 struct posix_acl *acl;
37 const struct xfs_acl_entry *ace;
38 unsigned int count, i;
39
40 if (len < sizeof(*aclp)) {
41 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
42 len);
43 return ERR_PTR(-EFSCORRUPTED);
44 }
45
46 count = be32_to_cpu(aclp->acl_cnt);
47 if (count > max_entries || XFS_ACL_SIZE(count) != len) {
48 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
49 len);
50 return ERR_PTR(-EFSCORRUPTED);
51 }
52
53 acl = posix_acl_alloc(count, GFP_KERNEL);
54 if (!acl)
55 return ERR_PTR(-ENOMEM);
56
57 for (i = 0; i < count; i++) {
58 acl_e = &acl->a_entries[i];
59 ace = &aclp->acl_entry[i];
60
61 /*
62 * The tag is 32 bits on disk and 16 bits in core.
63 *
64 * Because every access to it goes through the core
65 * format first this is not a problem.
66 */
67 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
68 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
69
70 switch (acl_e->e_tag) {
71 case ACL_USER:
72 acl_e->e_uid = make_kuid(&init_user_ns,
73 be32_to_cpu(ace->ae_id));
74 break;
75 case ACL_GROUP:
76 acl_e->e_gid = make_kgid(&init_user_ns,
77 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(
111 from_kuid(&init_user_ns, acl_e->e_uid));
112 break;
113 case ACL_GROUP:
114 ace->ae_id = cpu_to_be32(
115 from_kgid(&init_user_ns, acl_e->e_gid));
116 break;
117 default:
118 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
119 break;
120 }
121
122 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
123 }
124}
125
126struct posix_acl *
127xfs_get_acl(struct inode *inode, int type)
128{
129 struct xfs_inode *ip = XFS_I(inode);
130 struct xfs_mount *mp = ip->i_mount;
131 struct posix_acl *acl = NULL;
132 struct xfs_da_args args = {
133 .dp = ip,
134 .attr_filter = XFS_ATTR_ROOT,
135 .valuelen = XFS_ACL_MAX_SIZE(mp),
136 };
137 int error;
138
139 trace_xfs_get_acl(ip);
140
141 switch (type) {
142 case ACL_TYPE_ACCESS:
143 args.name = SGI_ACL_FILE;
144 break;
145 case ACL_TYPE_DEFAULT:
146 args.name = SGI_ACL_DEFAULT;
147 break;
148 default:
149 BUG();
150 }
151 args.namelen = strlen(args.name);
152
153 /*
154 * If the attribute doesn't exist make sure we have a negative cache
155 * entry, for any other error assume it is transient.
156 */
157 error = xfs_attr_get(&args);
158 if (!error) {
159 acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
160 XFS_ACL_MAX_ENTRIES(mp));
161 } else if (error != -ENOATTR) {
162 acl = ERR_PTR(error);
163 }
164
165 kmem_free(args.value);
166 return acl;
167}
168
169int
170__xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
171{
172 struct xfs_inode *ip = XFS_I(inode);
173 struct xfs_da_args args = {
174 .dp = ip,
175 .attr_filter = XFS_ATTR_ROOT,
176 };
177 int error;
178
179 switch (type) {
180 case ACL_TYPE_ACCESS:
181 args.name = SGI_ACL_FILE;
182 break;
183 case ACL_TYPE_DEFAULT:
184 if (!S_ISDIR(inode->i_mode))
185 return acl ? -EACCES : 0;
186 args.name = SGI_ACL_DEFAULT;
187 break;
188 default:
189 return -EINVAL;
190 }
191 args.namelen = strlen(args.name);
192
193 if (acl) {
194 args.valuelen = XFS_ACL_SIZE(acl->a_count);
195 args.value = kmem_zalloc_large(args.valuelen, 0);
196 if (!args.value)
197 return -ENOMEM;
198 xfs_acl_to_disk(args.value, acl);
199 }
200
201 error = xfs_attr_set(&args);
202 kmem_free(args.value);
203
204 /*
205 * If the attribute didn't exist to start with that's fine.
206 */
207 if (!acl && error == -ENOATTR)
208 error = 0;
209 if (!error)
210 set_cached_acl(inode, type, acl);
211 return error;
212}
213
214static int
215xfs_set_mode(struct inode *inode, umode_t mode)
216{
217 int error = 0;
218
219 if (mode != inode->i_mode) {
220 struct iattr iattr;
221
222 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
223 iattr.ia_mode = mode;
224 iattr.ia_ctime = current_time(inode);
225
226 error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
227 }
228
229 return error;
230}
231
232int
233xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
234{
235 umode_t mode;
236 bool set_mode = false;
237 int error = 0;
238
239 if (!acl)
240 goto set_acl;
241
242 error = -E2BIG;
243 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
244 return error;
245
246 if (type == ACL_TYPE_ACCESS) {
247 error = posix_acl_update_mode(inode, &mode, &acl);
248 if (error)
249 return error;
250 set_mode = true;
251 }
252
253 set_acl:
254 error = __xfs_set_acl(inode, acl, type);
255 if (error)
256 return error;
257
258 /*
259 * We set the mode after successfully updating the ACL xattr because the
260 * xattr update can fail at ENOSPC and we don't want to change the mode
261 * if the ACL update hasn't been applied.
262 */
263 if (set_mode)
264 error = xfs_set_mode(inode, mode);
265
266 return error;
267}
268
269/*
270 * Invalidate any cached ACLs if the user has bypassed the ACL interface.
271 * We don't validate the content whatsoever so it is caller responsibility to
272 * provide data in valid format and ensure i_mode is consistent.
273 */
274void
275xfs_forget_acl(
276 struct inode *inode,
277 const char *name)
278{
279 if (!strcmp(name, SGI_ACL_FILE))
280 forget_cached_acl(inode, ACL_TYPE_ACCESS);
281 else if (!strcmp(name, SGI_ACL_DEFAULT))
282 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
283}
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_da_format.h"
14#include "xfs_da_btree.h"
15#include "xfs_attr.h"
16#include "xfs_trace.h"
17#include "xfs_error.h"
18#include "xfs_acl.h"
19#include "xfs_trans.h"
20#include "xfs_xattr.h"
21
22#include <linux/posix_acl_xattr.h>
23
24/*
25 * Locking scheme:
26 * - all ACL updates are protected by inode->i_mutex, which is taken before
27 * calling into this file.
28 */
29
30STATIC struct posix_acl *
31xfs_acl_from_disk(
32 struct xfs_mount *mp,
33 const struct xfs_acl *aclp,
34 int len,
35 int max_entries)
36{
37 struct posix_acl_entry *acl_e;
38 struct posix_acl *acl;
39 const struct xfs_acl_entry *ace;
40 unsigned int count, i;
41
42 if (len < sizeof(*aclp)) {
43 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
44 len);
45 return ERR_PTR(-EFSCORRUPTED);
46 }
47
48 count = be32_to_cpu(aclp->acl_cnt);
49 if (count > max_entries || XFS_ACL_SIZE(count) != len) {
50 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp,
51 len);
52 return ERR_PTR(-EFSCORRUPTED);
53 }
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 = make_kuid(&init_user_ns,
75 be32_to_cpu(ace->ae_id));
76 break;
77 case ACL_GROUP:
78 acl_e->e_gid = make_kgid(&init_user_ns,
79 be32_to_cpu(ace->ae_id));
80 break;
81 case ACL_USER_OBJ:
82 case ACL_GROUP_OBJ:
83 case ACL_MASK:
84 case ACL_OTHER:
85 break;
86 default:
87 goto fail;
88 }
89 }
90 return acl;
91
92fail:
93 posix_acl_release(acl);
94 return ERR_PTR(-EINVAL);
95}
96
97STATIC void
98xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
99{
100 const struct posix_acl_entry *acl_e;
101 struct xfs_acl_entry *ace;
102 int i;
103
104 aclp->acl_cnt = cpu_to_be32(acl->a_count);
105 for (i = 0; i < acl->a_count; i++) {
106 ace = &aclp->acl_entry[i];
107 acl_e = &acl->a_entries[i];
108
109 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
110 switch (acl_e->e_tag) {
111 case ACL_USER:
112 ace->ae_id = cpu_to_be32(
113 from_kuid(&init_user_ns, acl_e->e_uid));
114 break;
115 case ACL_GROUP:
116 ace->ae_id = cpu_to_be32(
117 from_kgid(&init_user_ns, acl_e->e_gid));
118 break;
119 default:
120 ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
121 break;
122 }
123
124 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
125 }
126}
127
128struct posix_acl *
129xfs_get_acl(struct inode *inode, int type, bool rcu)
130{
131 struct xfs_inode *ip = XFS_I(inode);
132 struct xfs_mount *mp = ip->i_mount;
133 struct posix_acl *acl = NULL;
134 struct xfs_da_args args = {
135 .dp = ip,
136 .attr_filter = XFS_ATTR_ROOT,
137 .valuelen = XFS_ACL_MAX_SIZE(mp),
138 };
139 int error;
140
141 if (rcu)
142 return ERR_PTR(-ECHILD);
143
144 trace_xfs_get_acl(ip);
145
146 switch (type) {
147 case ACL_TYPE_ACCESS:
148 args.name = SGI_ACL_FILE;
149 break;
150 case ACL_TYPE_DEFAULT:
151 args.name = SGI_ACL_DEFAULT;
152 break;
153 default:
154 BUG();
155 }
156 args.namelen = strlen(args.name);
157
158 /*
159 * If the attribute doesn't exist make sure we have a negative cache
160 * entry, for any other error assume it is transient.
161 */
162 error = xfs_attr_get(&args);
163 if (!error) {
164 acl = xfs_acl_from_disk(mp, args.value, args.valuelen,
165 XFS_ACL_MAX_ENTRIES(mp));
166 } else if (error != -ENOATTR) {
167 acl = ERR_PTR(error);
168 }
169
170 kmem_free(args.value);
171 return acl;
172}
173
174int
175__xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
176{
177 struct xfs_inode *ip = XFS_I(inode);
178 struct xfs_da_args args = {
179 .dp = ip,
180 .attr_filter = XFS_ATTR_ROOT,
181 };
182 int error;
183
184 switch (type) {
185 case ACL_TYPE_ACCESS:
186 args.name = SGI_ACL_FILE;
187 break;
188 case ACL_TYPE_DEFAULT:
189 if (!S_ISDIR(inode->i_mode))
190 return acl ? -EACCES : 0;
191 args.name = SGI_ACL_DEFAULT;
192 break;
193 default:
194 return -EINVAL;
195 }
196 args.namelen = strlen(args.name);
197
198 if (acl) {
199 args.valuelen = XFS_ACL_SIZE(acl->a_count);
200 args.value = kvzalloc(args.valuelen, GFP_KERNEL);
201 if (!args.value)
202 return -ENOMEM;
203 xfs_acl_to_disk(args.value, acl);
204 }
205
206 error = xfs_attr_change(&args);
207 kmem_free(args.value);
208
209 /*
210 * If the attribute didn't exist to start with that's fine.
211 */
212 if (!acl && error == -ENOATTR)
213 error = 0;
214 if (!error)
215 set_cached_acl(inode, type, acl);
216 return error;
217}
218
219static int
220xfs_acl_set_mode(
221 struct inode *inode,
222 umode_t mode)
223{
224 struct xfs_inode *ip = XFS_I(inode);
225 struct xfs_mount *mp = ip->i_mount;
226 struct xfs_trans *tp;
227 int error;
228
229 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
230 if (error)
231 return error;
232
233 xfs_ilock(ip, XFS_ILOCK_EXCL);
234 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
235 inode->i_mode = mode;
236 inode_set_ctime_current(inode);
237 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
238
239 if (xfs_has_wsync(mp))
240 xfs_trans_set_sync(tp);
241 return xfs_trans_commit(tp);
242}
243
244int
245xfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
246 struct posix_acl *acl, int type)
247{
248 umode_t mode;
249 bool set_mode = false;
250 int error = 0;
251 struct inode *inode = d_inode(dentry);
252
253 if (!acl)
254 goto set_acl;
255
256 error = -E2BIG;
257 if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
258 return error;
259
260 if (type == ACL_TYPE_ACCESS) {
261 error = posix_acl_update_mode(idmap, inode, &mode, &acl);
262 if (error)
263 return error;
264 set_mode = true;
265 }
266
267 set_acl:
268 /*
269 * We set the mode after successfully updating the ACL xattr because the
270 * xattr update can fail at ENOSPC and we don't want to change the mode
271 * if the ACL update hasn't been applied.
272 */
273 error = __xfs_set_acl(inode, acl, type);
274 if (!error && set_mode && mode != inode->i_mode)
275 error = xfs_acl_set_mode(inode, mode);
276 return error;
277}
278
279/*
280 * Invalidate any cached ACLs if the user has bypassed the ACL interface.
281 * We don't validate the content whatsoever so it is caller responsibility to
282 * provide data in valid format and ensure i_mode is consistent.
283 */
284void
285xfs_forget_acl(
286 struct inode *inode,
287 const char *name)
288{
289 if (!strcmp(name, SGI_ACL_FILE))
290 forget_cached_acl(inode, ACL_TYPE_ACCESS);
291 else if (!strcmp(name, SGI_ACL_DEFAULT))
292 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
293}