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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#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}
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->i_ctime = current_time(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 user_namespace *mnt_userns, 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(mnt_userns, 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}