1 // SPDX-License-Identifier: GPL-2.0
2
3 #include "bcachefs.h"
4
5 #include "acl.h"
6 #include "xattr.h"
7
8 #include <linux/posix_acl.h>
9
10 static const char * const acl_types[] = {
11 [ACL_USER_OBJ] = "user_obj",
12 [ACL_USER] = "user",
13 [ACL_GROUP_OBJ] = "group_obj",
14 [ACL_GROUP] = "group",
15 [ACL_MASK] = "mask",
16 [ACL_OTHER] = "other",
17 NULL,
18 };
19
20 void bch2_acl_to_text(struct printbuf *out, const void *value, size_t size)
21 {
22 const void *p, *end = value + size;
23
24 if (!value ||
25 size < sizeof(bch_acl_header) ||
26 ((bch_acl_header *)value)->a_version != cpu_to_le32(BCH_ACL_VERSION))
27 return;
28
29 p = value + sizeof(bch_acl_header);
30 while (p < end) {
31 const bch_acl_entry *in = p;
32 unsigned tag = le16_to_cpu(in->e_tag);
33
34 prt_str(out, acl_types[tag]);
35
36 switch (tag) {
37 case ACL_USER_OBJ:
38 case ACL_GROUP_OBJ:
39 case ACL_MASK:
40 case ACL_OTHER:
41 p += sizeof(bch_acl_entry_short);
42 break;
43 case ACL_USER:
44 prt_printf(out, " uid %u", le32_to_cpu(in->e_id));
45 p += sizeof(bch_acl_entry);
46 break;
47 case ACL_GROUP:
48 prt_printf(out, " gid %u", le32_to_cpu(in->e_id));
49 p += sizeof(bch_acl_entry);
50 break;
51 }
52
53 prt_printf(out, " %o", le16_to_cpu(in->e_perm));
54
55 if (p != end)
56 prt_char(out, ' ');
57 }
58 }
59
60 #ifdef CONFIG_BCACHEFS_POSIX_ACL
61
62 #include "fs.h"
63
64 #include <linux/fs.h>
65 #include <linux/posix_acl_xattr.h>
66 #include <linux/sched.h>
67 #include <linux/slab.h>
68
69 static inline size_t bch2_acl_size(unsigned nr_short, unsigned nr_long)
70 {
71 return sizeof(bch_acl_header) +
72 sizeof(bch_acl_entry_short) * nr_short +
73 sizeof(bch_acl_entry) * nr_long;
74 }
75
76 static inline int acl_to_xattr_type(int type)
77 {
78 switch (type) {
79 case ACL_TYPE_ACCESS:
80 return KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS;
81 case ACL_TYPE_DEFAULT:
82 return KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT;
83 default:
84 BUG();
85 }
86 }
87
88 /*
89 * Convert from filesystem to in-memory representation.
90 */
91 static struct posix_acl *bch2_acl_from_disk(struct btree_trans *trans,
92 const void *value, size_t size)
93 {
94 const void *p, *end = value + size;
95 struct posix_acl *acl;
96 struct posix_acl_entry *out;
97 unsigned count = 0;
98 int ret;
99
100 if (!value)
101 return NULL;
102 if (size < sizeof(bch_acl_header))
103 goto invalid;
104 if (((bch_acl_header *)value)->a_version !=
105 cpu_to_le32(BCH_ACL_VERSION))
106 goto invalid;
107
108 p = value + sizeof(bch_acl_header);
109 while (p < end) {
110 const bch_acl_entry *entry = p;
111
112 if (p + sizeof(bch_acl_entry_short) > end)
113 goto invalid;
114
115 switch (le16_to_cpu(entry->e_tag)) {
116 case ACL_USER_OBJ:
117 case ACL_GROUP_OBJ:
118 case ACL_MASK:
119 case ACL_OTHER:
120 p += sizeof(bch_acl_entry_short);
121 break;
122 case ACL_USER:
123 case ACL_GROUP:
124 p += sizeof(bch_acl_entry);
125 break;
126 default:
127 goto invalid;
128 }
129
130 count++;
131 }
132
133 if (p > end)
134 goto invalid;
135
136 if (!count)
137 return NULL;
138
139 acl = allocate_dropping_locks(trans, ret,
140 posix_acl_alloc(count, _gfp));
141 if (!acl)
142 return ERR_PTR(-ENOMEM);
143 if (ret) {
144 kfree(acl);
145 return ERR_PTR(ret);
146 }
147
148 out = acl->a_entries;
149
150 p = value + sizeof(bch_acl_header);
151 while (p < end) {
152 const bch_acl_entry *in = p;
153
154 out->e_tag = le16_to_cpu(in->e_tag);
155 out->e_perm = le16_to_cpu(in->e_perm);
156
157 switch (out->e_tag) {
158 case ACL_USER_OBJ:
159 case ACL_GROUP_OBJ:
160 case ACL_MASK:
161 case ACL_OTHER:
162 p += sizeof(bch_acl_entry_short);
163 break;
164 case ACL_USER:
165 out->e_uid = make_kuid(&init_user_ns,
166 le32_to_cpu(in->e_id));
167 p += sizeof(bch_acl_entry);
168 break;
169 case ACL_GROUP:
170 out->e_gid = make_kgid(&init_user_ns,
171 le32_to_cpu(in->e_id));
172 p += sizeof(bch_acl_entry);
173 break;
174 }
175
176 out++;
177 }
178
179 BUG_ON(out != acl->a_entries + acl->a_count);
180
181 return acl;
182 invalid:
183 pr_err("invalid acl entry");
184 return ERR_PTR(-EINVAL);
185 }
186
187 #define acl_for_each_entry(acl, acl_e) \
188 for (acl_e = acl->a_entries; \
189 acl_e < acl->a_entries + acl->a_count; \
190 acl_e++)
191
192 /*
193 * Convert from in-memory to filesystem representation.
194 */
195 static struct bkey_i_xattr *
196 bch2_acl_to_xattr(struct btree_trans *trans,
197 const struct posix_acl *acl,
198 int type)
199 {
200 struct bkey_i_xattr *xattr;
201 bch_acl_header *acl_header;
202 const struct posix_acl_entry *acl_e;
203 void *outptr;
204 unsigned nr_short = 0, nr_long = 0, acl_len, u64s;
205
206 acl_for_each_entry(acl, acl_e) {
207 switch (acl_e->e_tag) {
208 case ACL_USER:
209 case ACL_GROUP:
210 nr_long++;
211 break;
212 case ACL_USER_OBJ:
213 case ACL_GROUP_OBJ:
214 case ACL_MASK:
215 case ACL_OTHER:
216 nr_short++;
217 break;
218 default:
219 return ERR_PTR(-EINVAL);
220 }
221 }
222
223 acl_len = bch2_acl_size(nr_short, nr_long);
224 u64s = BKEY_U64s + xattr_val_u64s(0, acl_len);
225
226 if (u64s > U8_MAX)
227 return ERR_PTR(-E2BIG);
228
229 xattr = bch2_trans_kmalloc(trans, u64s * sizeof(u64));
230 if (IS_ERR(xattr))
231 return xattr;
232
233 bkey_xattr_init(&xattr->k_i);
234 xattr->k.u64s = u64s;
235 xattr->v.x_type = acl_to_xattr_type(type);
236 xattr->v.x_name_len = 0;
237 xattr->v.x_val_len = cpu_to_le16(acl_len);
238
239 acl_header = xattr_val(&xattr->v);
240 acl_header->a_version = cpu_to_le32(BCH_ACL_VERSION);
241
242 outptr = (void *) acl_header + sizeof(*acl_header);
243
244 acl_for_each_entry(acl, acl_e) {
245 bch_acl_entry *entry = outptr;
246
247 entry->e_tag = cpu_to_le16(acl_e->e_tag);
248 entry->e_perm = cpu_to_le16(acl_e->e_perm);
249 switch (acl_e->e_tag) {
250 case ACL_USER:
251 entry->e_id = cpu_to_le32(
252 from_kuid(&init_user_ns, acl_e->e_uid));
253 outptr += sizeof(bch_acl_entry);
254 break;
255 case ACL_GROUP:
256 entry->e_id = cpu_to_le32(
257 from_kgid(&init_user_ns, acl_e->e_gid));
258 outptr += sizeof(bch_acl_entry);
259 break;
260
261 case ACL_USER_OBJ:
262 case ACL_GROUP_OBJ:
263 case ACL_MASK:
264 case ACL_OTHER:
265 outptr += sizeof(bch_acl_entry_short);
266 break;
267 }
268 }
269
270 BUG_ON(outptr != xattr_val(&xattr->v) + acl_len);
271
272 return xattr;
273 }
274
275 struct posix_acl *bch2_get_acl(struct inode *vinode, int type, bool rcu)
276 {
277 struct bch_inode_info *inode = to_bch_ei(vinode);
278 struct bch_fs *c = inode->v.i_sb->s_fs_info;
279 struct bch_hash_info hash = bch2_hash_info_init(c, &inode->ei_inode);
280 struct xattr_search_key search = X_SEARCH(acl_to_xattr_type(type), "", 0);
281 struct btree_iter iter = { NULL };
282 struct posix_acl *acl = NULL;
283
284 if (rcu)
285 return ERR_PTR(-ECHILD);
286
287 struct btree_trans *trans = bch2_trans_get(c);
288 retry:
289 bch2_trans_begin(trans);
290
291 struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
292 &hash, inode_inum(inode), &search, 0);
293 int ret = bkey_err(k);
294 if (ret)
295 goto err;
296
297 struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
298 acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),
299 le16_to_cpu(xattr.v->x_val_len));
300 ret = PTR_ERR_OR_ZERO(acl);
301 err:
302 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
303 goto retry;
304
305 if (ret)
306 acl = !bch2_err_matches(ret, ENOENT) ? ERR_PTR(ret) : NULL;
307
308 if (!IS_ERR_OR_NULL(acl))
309 set_cached_acl(&inode->v, type, acl);
310
311 bch2_trans_iter_exit(trans, &iter);
312 bch2_trans_put(trans);
313 return acl;
314 }
315
316 int bch2_set_acl_trans(struct btree_trans *trans, subvol_inum inum,
317 struct bch_inode_unpacked *inode_u,
318 struct posix_acl *acl, int type)
319 {
320 struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode_u);
321 int ret;
322
323 if (type == ACL_TYPE_DEFAULT &&
324 !S_ISDIR(inode_u->bi_mode))
325 return acl ? -EACCES : 0;
326
327 if (acl) {
328 struct bkey_i_xattr *xattr =
329 bch2_acl_to_xattr(trans, acl, type);
330 if (IS_ERR(xattr))
331 return PTR_ERR(xattr);
332
333 ret = bch2_hash_set(trans, bch2_xattr_hash_desc, &hash_info,
334 inum, &xattr->k_i, 0);
335 } else {
336 struct xattr_search_key search =
337 X_SEARCH(acl_to_xattr_type(type), "", 0);
338
339 ret = bch2_hash_delete(trans, bch2_xattr_hash_desc, &hash_info,
340 inum, &search);
341 }
342
343 return bch2_err_matches(ret, ENOENT) ? 0 : ret;
344 }
345
346 int bch2_set_acl(struct mnt_idmap *idmap,
347 struct dentry *dentry,
348 struct posix_acl *_acl, int type)
349 {
350 struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);
351 struct bch_fs *c = inode->v.i_sb->s_fs_info;
352 struct btree_iter inode_iter = { NULL };
353 struct bch_inode_unpacked inode_u;
354 struct posix_acl *acl;
355 umode_t mode;
356 int ret;
357
358 mutex_lock(&inode->ei_update_lock);
359 struct btree_trans *trans = bch2_trans_get(c);
360 retry:
361 bch2_trans_begin(trans);
362 acl = _acl;
363
364 ret = bch2_subvol_is_ro_trans(trans, inode->ei_subvol) ?:
365 bch2_inode_peek(trans, &inode_iter, &inode_u, inode_inum(inode),
366 BTREE_ITER_intent);
367 if (ret)
368 goto btree_err;
369
370 mode = inode_u.bi_mode;
371
372 if (type == ACL_TYPE_ACCESS) {
373 ret = posix_acl_update_mode(idmap, &inode->v, &mode, &acl);
374 if (ret)
375 goto btree_err;
376 }
377
378 ret = bch2_set_acl_trans(trans, inode_inum(inode), &inode_u, acl, type);
379 if (ret)
380 goto btree_err;
381
382 inode_u.bi_ctime = bch2_current_time(c);
383 inode_u.bi_mode = mode;
384
385 ret = bch2_inode_write(trans, &inode_iter, &inode_u) ?:
386 bch2_trans_commit(trans, NULL, NULL, 0);
387 btree_err:
388 bch2_trans_iter_exit(trans, &inode_iter);
389
390 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
391 goto retry;
392 if (unlikely(ret))
393 goto err;
394
395 bch2_inode_update_after_write(trans, inode, &inode_u,
396 ATTR_CTIME|ATTR_MODE);
397
398 set_cached_acl(&inode->v, type, acl);
399 err:
400 bch2_trans_put(trans);
401 mutex_unlock(&inode->ei_update_lock);
402
403 return ret;
404 }
405
406 int bch2_acl_chmod(struct btree_trans *trans, subvol_inum inum,
407 struct bch_inode_unpacked *inode,
408 umode_t mode,
409 struct posix_acl **new_acl)
410 {
411 struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode);
412 struct xattr_search_key search = X_SEARCH(KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS, "", 0);
413 struct btree_iter iter;
414 struct posix_acl *acl = NULL;
415
416 struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
417 &hash_info, inum, &search, BTREE_ITER_intent);
418 int ret = bkey_err(k);
419 if (ret)
420 return bch2_err_matches(ret, ENOENT) ? 0 : ret;
421
422 struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
423
424 acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),
425 le16_to_cpu(xattr.v->x_val_len));
426 ret = PTR_ERR_OR_ZERO(acl);
427 if (ret)
428 goto err;
429
430 ret = allocate_dropping_locks_errcode(trans, __posix_acl_chmod(&acl, _gfp, mode));
431 if (ret)
432 goto err;
433
434 struct bkey_i_xattr *new = bch2_acl_to_xattr(trans, acl, ACL_TYPE_ACCESS);
435 ret = PTR_ERR_OR_ZERO(new);
436 if (ret)
437 goto err;
438
439 new->k.p = iter.pos;
440 ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
441 *new_acl = acl;
442 acl = NULL;
443 err:
444 bch2_trans_iter_exit(trans, &iter);
445 if (!IS_ERR_OR_NULL(acl))
446 kfree(acl);
447 return ret;
448 }
449
450 #endif /* CONFIG_BCACHEFS_POSIX_ACL */
451
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