xref: /linux/fs/bcachefs/fs-common.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include "bcachefs.h"
4 #include "acl.h"
5 #include "btree_update.h"
6 #include "dirent.h"
7 #include "fs-common.h"
8 #include "inode.h"
9 #include "subvolume.h"
10 #include "xattr.h"
11 
12 #include <linux/posix_acl.h>
13 
14 static inline int is_subdir_for_nlink(struct bch_inode_unpacked *inode)
15 {
16 	return S_ISDIR(inode->bi_mode) && !inode->bi_subvol;
17 }
18 
19 int bch2_create_trans(struct btree_trans *trans,
20 		      subvol_inum dir,
21 		      struct bch_inode_unpacked *dir_u,
22 		      struct bch_inode_unpacked *new_inode,
23 		      const struct qstr *name,
24 		      uid_t uid, gid_t gid, umode_t mode, dev_t rdev,
25 		      struct posix_acl *default_acl,
26 		      struct posix_acl *acl,
27 		      subvol_inum snapshot_src,
28 		      unsigned flags)
29 {
30 	struct bch_fs *c = trans->c;
31 	struct btree_iter dir_iter = { NULL };
32 	struct btree_iter inode_iter = { NULL };
33 	subvol_inum new_inum = dir;
34 	u64 now = bch2_current_time(c);
35 	u64 cpu = raw_smp_processor_id();
36 	u64 dir_target;
37 	u32 snapshot;
38 	unsigned dir_type = mode_to_type(mode);
39 	int ret;
40 
41 	ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot);
42 	if (ret)
43 		goto err;
44 
45 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
46 	if (ret)
47 		goto err;
48 
49 	if (!(flags & BCH_CREATE_SNAPSHOT)) {
50 		/* Normal create path - allocate a new inode: */
51 		bch2_inode_init_late(new_inode, now, uid, gid, mode, rdev, dir_u);
52 
53 		if (flags & BCH_CREATE_TMPFILE)
54 			new_inode->bi_flags |= BCH_INODE_unlinked;
55 
56 		ret = bch2_inode_create(trans, &inode_iter, new_inode, snapshot, cpu);
57 		if (ret)
58 			goto err;
59 
60 		snapshot_src = (subvol_inum) { 0 };
61 	} else {
62 		/*
63 		 * Creating a snapshot - we're not allocating a new inode, but
64 		 * we do have to lookup the root inode of the subvolume we're
65 		 * snapshotting and update it (in the new snapshot):
66 		 */
67 
68 		if (!snapshot_src.inum) {
69 			/* Inode wasn't specified, just snapshot: */
70 			struct bch_subvolume s;
71 
72 			ret = bch2_subvolume_get(trans, snapshot_src.subvol, true,
73 						 BTREE_ITER_cached, &s);
74 			if (ret)
75 				goto err;
76 
77 			snapshot_src.inum = le64_to_cpu(s.inode);
78 		}
79 
80 		ret = bch2_inode_peek(trans, &inode_iter, new_inode, snapshot_src,
81 				      BTREE_ITER_intent);
82 		if (ret)
83 			goto err;
84 
85 		if (new_inode->bi_subvol != snapshot_src.subvol) {
86 			/* Not a subvolume root: */
87 			ret = -EINVAL;
88 			goto err;
89 		}
90 
91 		/*
92 		 * If we're not root, we have to own the subvolume being
93 		 * snapshotted:
94 		 */
95 		if (uid && new_inode->bi_uid != uid) {
96 			ret = -EPERM;
97 			goto err;
98 		}
99 
100 		flags |= BCH_CREATE_SUBVOL;
101 	}
102 
103 	new_inum.inum	= new_inode->bi_inum;
104 	dir_target	= new_inode->bi_inum;
105 
106 	if (flags & BCH_CREATE_SUBVOL) {
107 		u32 new_subvol, dir_snapshot;
108 
109 		ret = bch2_subvolume_create(trans, new_inode->bi_inum,
110 					    dir.subvol,
111 					    snapshot_src.subvol,
112 					    &new_subvol, &snapshot,
113 					    (flags & BCH_CREATE_SNAPSHOT_RO) != 0);
114 		if (ret)
115 			goto err;
116 
117 		new_inode->bi_parent_subvol	= dir.subvol;
118 		new_inode->bi_subvol		= new_subvol;
119 		new_inum.subvol			= new_subvol;
120 		dir_target			= new_subvol;
121 		dir_type			= DT_SUBVOL;
122 
123 		ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &dir_snapshot);
124 		if (ret)
125 			goto err;
126 
127 		bch2_btree_iter_set_snapshot(&dir_iter, dir_snapshot);
128 		ret = bch2_btree_iter_traverse(&dir_iter);
129 		if (ret)
130 			goto err;
131 	}
132 
133 	if (!(flags & BCH_CREATE_SNAPSHOT)) {
134 		if (default_acl) {
135 			ret = bch2_set_acl_trans(trans, new_inum, new_inode,
136 						 default_acl, ACL_TYPE_DEFAULT);
137 			if (ret)
138 				goto err;
139 		}
140 
141 		if (acl) {
142 			ret = bch2_set_acl_trans(trans, new_inum, new_inode,
143 						 acl, ACL_TYPE_ACCESS);
144 			if (ret)
145 				goto err;
146 		}
147 	}
148 
149 	if (!(flags & BCH_CREATE_TMPFILE)) {
150 		struct bch_hash_info dir_hash = bch2_hash_info_init(c, dir_u);
151 		u64 dir_offset;
152 
153 		if (is_subdir_for_nlink(new_inode))
154 			dir_u->bi_nlink++;
155 		dir_u->bi_mtime = dir_u->bi_ctime = now;
156 
157 		ret = bch2_inode_write(trans, &dir_iter, dir_u);
158 		if (ret)
159 			goto err;
160 
161 		ret = bch2_dirent_create(trans, dir, &dir_hash,
162 					 dir_type,
163 					 name,
164 					 dir_target,
165 					 &dir_offset,
166 					 STR_HASH_must_create);
167 		if (ret)
168 			goto err;
169 
170 		new_inode->bi_dir		= dir_u->bi_inum;
171 		new_inode->bi_dir_offset	= dir_offset;
172 	}
173 
174 	inode_iter.flags &= ~BTREE_ITER_all_snapshots;
175 	bch2_btree_iter_set_snapshot(&inode_iter, snapshot);
176 
177 	ret   = bch2_btree_iter_traverse(&inode_iter) ?:
178 		bch2_inode_write(trans, &inode_iter, new_inode);
179 err:
180 	bch2_trans_iter_exit(trans, &inode_iter);
181 	bch2_trans_iter_exit(trans, &dir_iter);
182 	return ret;
183 }
184 
185 int bch2_link_trans(struct btree_trans *trans,
186 		    subvol_inum dir,  struct bch_inode_unpacked *dir_u,
187 		    subvol_inum inum, struct bch_inode_unpacked *inode_u,
188 		    const struct qstr *name)
189 {
190 	struct bch_fs *c = trans->c;
191 	struct btree_iter dir_iter = { NULL };
192 	struct btree_iter inode_iter = { NULL };
193 	struct bch_hash_info dir_hash;
194 	u64 now = bch2_current_time(c);
195 	u64 dir_offset = 0;
196 	int ret;
197 
198 	if (dir.subvol != inum.subvol)
199 		return -EXDEV;
200 
201 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_intent);
202 	if (ret)
203 		return ret;
204 
205 	inode_u->bi_ctime = now;
206 	ret = bch2_inode_nlink_inc(inode_u);
207 	if (ret)
208 		goto err;
209 
210 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
211 	if (ret)
212 		goto err;
213 
214 	if (bch2_reinherit_attrs(inode_u, dir_u)) {
215 		ret = -EXDEV;
216 		goto err;
217 	}
218 
219 	dir_u->bi_mtime = dir_u->bi_ctime = now;
220 
221 	dir_hash = bch2_hash_info_init(c, dir_u);
222 
223 	ret = bch2_dirent_create(trans, dir, &dir_hash,
224 				 mode_to_type(inode_u->bi_mode),
225 				 name, inum.inum, &dir_offset,
226 				 STR_HASH_must_create);
227 	if (ret)
228 		goto err;
229 
230 	inode_u->bi_dir		= dir.inum;
231 	inode_u->bi_dir_offset	= dir_offset;
232 
233 	ret =   bch2_inode_write(trans, &dir_iter, dir_u) ?:
234 		bch2_inode_write(trans, &inode_iter, inode_u);
235 err:
236 	bch2_trans_iter_exit(trans, &dir_iter);
237 	bch2_trans_iter_exit(trans, &inode_iter);
238 	return ret;
239 }
240 
241 int bch2_unlink_trans(struct btree_trans *trans,
242 		      subvol_inum dir,
243 		      struct bch_inode_unpacked *dir_u,
244 		      struct bch_inode_unpacked *inode_u,
245 		      const struct qstr *name,
246 		      bool deleting_subvol)
247 {
248 	struct bch_fs *c = trans->c;
249 	struct btree_iter dir_iter = { NULL };
250 	struct btree_iter dirent_iter = { NULL };
251 	struct btree_iter inode_iter = { NULL };
252 	struct bch_hash_info dir_hash;
253 	subvol_inum inum;
254 	u64 now = bch2_current_time(c);
255 	struct bkey_s_c k;
256 	int ret;
257 
258 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
259 	if (ret)
260 		goto err;
261 
262 	dir_hash = bch2_hash_info_init(c, dir_u);
263 
264 	ret = bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
265 				       name, &inum, BTREE_ITER_intent);
266 	if (ret)
267 		goto err;
268 
269 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum,
270 			      BTREE_ITER_intent);
271 	if (ret)
272 		goto err;
273 
274 	if (!deleting_subvol && S_ISDIR(inode_u->bi_mode)) {
275 		ret = bch2_empty_dir_trans(trans, inum);
276 		if (ret)
277 			goto err;
278 	}
279 
280 	if (deleting_subvol && !inode_u->bi_subvol) {
281 		ret = -BCH_ERR_ENOENT_not_subvol;
282 		goto err;
283 	}
284 
285 	if (inode_u->bi_subvol) {
286 		/* Recursive subvolume destroy not allowed (yet?) */
287 		ret = bch2_subvol_has_children(trans, inode_u->bi_subvol);
288 		if (ret)
289 			goto err;
290 	}
291 
292 	if (deleting_subvol || inode_u->bi_subvol) {
293 		ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
294 		if (ret)
295 			goto err;
296 
297 		k = bch2_btree_iter_peek_slot(&dirent_iter);
298 		ret = bkey_err(k);
299 		if (ret)
300 			goto err;
301 
302 		/*
303 		 * If we're deleting a subvolume, we need to really delete the
304 		 * dirent, not just emit a whiteout in the current snapshot:
305 		 */
306 		bch2_btree_iter_set_snapshot(&dirent_iter, k.k->p.snapshot);
307 		ret = bch2_btree_iter_traverse(&dirent_iter);
308 		if (ret)
309 			goto err;
310 	} else {
311 		bch2_inode_nlink_dec(trans, inode_u);
312 	}
313 
314 	if (inode_u->bi_dir		== dirent_iter.pos.inode &&
315 	    inode_u->bi_dir_offset	== dirent_iter.pos.offset) {
316 		inode_u->bi_dir		= 0;
317 		inode_u->bi_dir_offset	= 0;
318 	}
319 
320 	dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
321 	dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
322 
323 	ret =   bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
324 				    &dir_hash, &dirent_iter,
325 				    BTREE_UPDATE_internal_snapshot_node) ?:
326 		bch2_inode_write(trans, &dir_iter, dir_u) ?:
327 		bch2_inode_write(trans, &inode_iter, inode_u);
328 err:
329 	bch2_trans_iter_exit(trans, &inode_iter);
330 	bch2_trans_iter_exit(trans, &dirent_iter);
331 	bch2_trans_iter_exit(trans, &dir_iter);
332 	return ret;
333 }
334 
335 bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
336 			  struct bch_inode_unpacked *src_u)
337 {
338 	u64 src, dst;
339 	unsigned id;
340 	bool ret = false;
341 
342 	for (id = 0; id < Inode_opt_nr; id++) {
343 		/* Skip attributes that were explicitly set on this inode */
344 		if (dst_u->bi_fields_set & (1 << id))
345 			continue;
346 
347 		src = bch2_inode_opt_get(src_u, id);
348 		dst = bch2_inode_opt_get(dst_u, id);
349 
350 		if (src == dst)
351 			continue;
352 
353 		bch2_inode_opt_set(dst_u, id, src);
354 		ret = true;
355 	}
356 
357 	return ret;
358 }
359 
360 static int subvol_update_parent(struct btree_trans *trans, u32 subvol, u32 new_parent)
361 {
362 	struct btree_iter iter;
363 	struct bkey_i_subvolume *s =
364 		bch2_bkey_get_mut_typed(trans, &iter,
365 			BTREE_ID_subvolumes, POS(0, subvol),
366 			BTREE_ITER_cached, subvolume);
367 	int ret = PTR_ERR_OR_ZERO(s);
368 	if (ret)
369 		return ret;
370 
371 	s->v.fs_path_parent = cpu_to_le32(new_parent);
372 	bch2_trans_iter_exit(trans, &iter);
373 	return 0;
374 }
375 
376 int bch2_rename_trans(struct btree_trans *trans,
377 		      subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u,
378 		      subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u,
379 		      struct bch_inode_unpacked *src_inode_u,
380 		      struct bch_inode_unpacked *dst_inode_u,
381 		      const struct qstr *src_name,
382 		      const struct qstr *dst_name,
383 		      enum bch_rename_mode mode)
384 {
385 	struct bch_fs *c = trans->c;
386 	struct btree_iter src_dir_iter = { NULL };
387 	struct btree_iter dst_dir_iter = { NULL };
388 	struct btree_iter src_inode_iter = { NULL };
389 	struct btree_iter dst_inode_iter = { NULL };
390 	struct bch_hash_info src_hash, dst_hash;
391 	subvol_inum src_inum, dst_inum;
392 	u64 src_offset, dst_offset;
393 	u64 now = bch2_current_time(c);
394 	int ret;
395 
396 	ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir,
397 			      BTREE_ITER_intent);
398 	if (ret)
399 		goto err;
400 
401 	src_hash = bch2_hash_info_init(c, src_dir_u);
402 
403 	if (dst_dir.inum	!= src_dir.inum ||
404 	    dst_dir.subvol	!= src_dir.subvol) {
405 		ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir,
406 				      BTREE_ITER_intent);
407 		if (ret)
408 			goto err;
409 
410 		dst_hash = bch2_hash_info_init(c, dst_dir_u);
411 	} else {
412 		dst_dir_u = src_dir_u;
413 		dst_hash = src_hash;
414 	}
415 
416 	ret = bch2_dirent_rename(trans,
417 				 src_dir, &src_hash,
418 				 dst_dir, &dst_hash,
419 				 src_name, &src_inum, &src_offset,
420 				 dst_name, &dst_inum, &dst_offset,
421 				 mode);
422 	if (ret)
423 		goto err;
424 
425 	ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum,
426 			      BTREE_ITER_intent);
427 	if (ret)
428 		goto err;
429 
430 	if (dst_inum.inum) {
431 		ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum,
432 				      BTREE_ITER_intent);
433 		if (ret)
434 			goto err;
435 	}
436 
437 	if (src_inode_u->bi_subvol &&
438 	    dst_dir.subvol != src_inode_u->bi_parent_subvol) {
439 		ret = subvol_update_parent(trans, src_inode_u->bi_subvol, dst_dir.subvol);
440 		if (ret)
441 			goto err;
442 	}
443 
444 	if (mode == BCH_RENAME_EXCHANGE &&
445 	    dst_inode_u->bi_subvol &&
446 	    src_dir.subvol != dst_inode_u->bi_parent_subvol) {
447 		ret = subvol_update_parent(trans, dst_inode_u->bi_subvol, src_dir.subvol);
448 		if (ret)
449 			goto err;
450 	}
451 
452 	/* Can't move across subvolumes, unless it's a subvolume root: */
453 	if (src_dir.subvol != dst_dir.subvol &&
454 	    (!src_inode_u->bi_subvol ||
455 	     (dst_inum.inum && !dst_inode_u->bi_subvol))) {
456 		ret = -EXDEV;
457 		goto err;
458 	}
459 
460 	if (src_inode_u->bi_parent_subvol)
461 		src_inode_u->bi_parent_subvol = dst_dir.subvol;
462 
463 	if ((mode == BCH_RENAME_EXCHANGE) &&
464 	    dst_inode_u->bi_parent_subvol)
465 		dst_inode_u->bi_parent_subvol = src_dir.subvol;
466 
467 	src_inode_u->bi_dir		= dst_dir_u->bi_inum;
468 	src_inode_u->bi_dir_offset	= dst_offset;
469 
470 	if (mode == BCH_RENAME_EXCHANGE) {
471 		dst_inode_u->bi_dir		= src_dir_u->bi_inum;
472 		dst_inode_u->bi_dir_offset	= src_offset;
473 	}
474 
475 	if (mode == BCH_RENAME_OVERWRITE &&
476 	    dst_inode_u->bi_dir		== dst_dir_u->bi_inum &&
477 	    dst_inode_u->bi_dir_offset	== src_offset) {
478 		dst_inode_u->bi_dir		= 0;
479 		dst_inode_u->bi_dir_offset	= 0;
480 	}
481 
482 	if (mode == BCH_RENAME_OVERWRITE) {
483 		if (S_ISDIR(src_inode_u->bi_mode) !=
484 		    S_ISDIR(dst_inode_u->bi_mode)) {
485 			ret = -ENOTDIR;
486 			goto err;
487 		}
488 
489 		if (S_ISDIR(dst_inode_u->bi_mode)) {
490 			ret = bch2_empty_dir_trans(trans, dst_inum);
491 			if (ret)
492 				goto err;
493 		}
494 	}
495 
496 	if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) &&
497 	    S_ISDIR(src_inode_u->bi_mode)) {
498 		ret = -EXDEV;
499 		goto err;
500 	}
501 
502 	if (mode == BCH_RENAME_EXCHANGE &&
503 	    bch2_reinherit_attrs(dst_inode_u, src_dir_u) &&
504 	    S_ISDIR(dst_inode_u->bi_mode)) {
505 		ret = -EXDEV;
506 		goto err;
507 	}
508 
509 	if (is_subdir_for_nlink(src_inode_u)) {
510 		src_dir_u->bi_nlink--;
511 		dst_dir_u->bi_nlink++;
512 	}
513 
514 	if (dst_inum.inum && is_subdir_for_nlink(dst_inode_u)) {
515 		dst_dir_u->bi_nlink--;
516 		src_dir_u->bi_nlink += mode == BCH_RENAME_EXCHANGE;
517 	}
518 
519 	if (mode == BCH_RENAME_OVERWRITE)
520 		bch2_inode_nlink_dec(trans, dst_inode_u);
521 
522 	src_dir_u->bi_mtime		= now;
523 	src_dir_u->bi_ctime		= now;
524 
525 	if (src_dir.inum != dst_dir.inum) {
526 		dst_dir_u->bi_mtime	= now;
527 		dst_dir_u->bi_ctime	= now;
528 	}
529 
530 	src_inode_u->bi_ctime		= now;
531 
532 	if (dst_inum.inum)
533 		dst_inode_u->bi_ctime	= now;
534 
535 	ret =   bch2_inode_write(trans, &src_dir_iter, src_dir_u) ?:
536 		(src_dir.inum != dst_dir.inum
537 		 ? bch2_inode_write(trans, &dst_dir_iter, dst_dir_u)
538 		 : 0) ?:
539 		bch2_inode_write(trans, &src_inode_iter, src_inode_u) ?:
540 		(dst_inum.inum
541 		 ? bch2_inode_write(trans, &dst_inode_iter, dst_inode_u)
542 		 : 0);
543 err:
544 	bch2_trans_iter_exit(trans, &dst_inode_iter);
545 	bch2_trans_iter_exit(trans, &src_inode_iter);
546 	bch2_trans_iter_exit(trans, &dst_dir_iter);
547 	bch2_trans_iter_exit(trans, &src_dir_iter);
548 	return ret;
549 }
550