xref: /linux/fs/bcachefs/fs-common.c (revision 9e87705289667a6c5185c619ea32f3d39314eb1b)
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 					    snapshot_src.subvol,
111 					    &new_subvol, &snapshot,
112 					    (flags & BCH_CREATE_SNAPSHOT_RO) != 0);
113 		if (ret)
114 			goto err;
115 
116 		new_inode->bi_parent_subvol	= dir.subvol;
117 		new_inode->bi_subvol		= new_subvol;
118 		new_inum.subvol			= new_subvol;
119 		dir_target			= new_subvol;
120 		dir_type			= DT_SUBVOL;
121 
122 		ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &dir_snapshot);
123 		if (ret)
124 			goto err;
125 
126 		bch2_btree_iter_set_snapshot(&dir_iter, dir_snapshot);
127 		ret = bch2_btree_iter_traverse(&dir_iter);
128 		if (ret)
129 			goto err;
130 	}
131 
132 	if (!(flags & BCH_CREATE_SNAPSHOT)) {
133 		if (default_acl) {
134 			ret = bch2_set_acl_trans(trans, new_inum, new_inode,
135 						 default_acl, ACL_TYPE_DEFAULT);
136 			if (ret)
137 				goto err;
138 		}
139 
140 		if (acl) {
141 			ret = bch2_set_acl_trans(trans, new_inum, new_inode,
142 						 acl, ACL_TYPE_ACCESS);
143 			if (ret)
144 				goto err;
145 		}
146 	}
147 
148 	if (!(flags & BCH_CREATE_TMPFILE)) {
149 		struct bch_hash_info dir_hash = bch2_hash_info_init(c, dir_u);
150 		u64 dir_offset;
151 
152 		if (is_subdir_for_nlink(new_inode))
153 			dir_u->bi_nlink++;
154 		dir_u->bi_mtime = dir_u->bi_ctime = now;
155 
156 		ret = bch2_inode_write(trans, &dir_iter, dir_u);
157 		if (ret)
158 			goto err;
159 
160 		ret = bch2_dirent_create(trans, dir, &dir_hash,
161 					 dir_type,
162 					 name,
163 					 dir_target,
164 					 &dir_offset,
165 					 BCH_HASH_SET_MUST_CREATE);
166 		if (ret)
167 			goto err;
168 
169 		if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
170 			new_inode->bi_dir		= dir_u->bi_inum;
171 			new_inode->bi_dir_offset	= dir_offset;
172 		}
173 	}
174 
175 	inode_iter.flags &= ~BTREE_ITER_ALL_SNAPSHOTS;
176 	bch2_btree_iter_set_snapshot(&inode_iter, snapshot);
177 
178 	ret   = bch2_btree_iter_traverse(&inode_iter) ?:
179 		bch2_inode_write(trans, &inode_iter, new_inode);
180 err:
181 	bch2_trans_iter_exit(trans, &inode_iter);
182 	bch2_trans_iter_exit(trans, &dir_iter);
183 	return ret;
184 }
185 
186 int bch2_link_trans(struct btree_trans *trans,
187 		    subvol_inum dir,  struct bch_inode_unpacked *dir_u,
188 		    subvol_inum inum, struct bch_inode_unpacked *inode_u,
189 		    const struct qstr *name)
190 {
191 	struct bch_fs *c = trans->c;
192 	struct btree_iter dir_iter = { NULL };
193 	struct btree_iter inode_iter = { NULL };
194 	struct bch_hash_info dir_hash;
195 	u64 now = bch2_current_time(c);
196 	u64 dir_offset = 0;
197 	int ret;
198 
199 	if (dir.subvol != inum.subvol)
200 		return -EXDEV;
201 
202 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_INTENT);
203 	if (ret)
204 		goto err;
205 
206 	inode_u->bi_ctime = now;
207 	ret = bch2_inode_nlink_inc(inode_u);
208 	if (ret)
209 		return ret;
210 
211 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
212 	if (ret)
213 		goto err;
214 
215 	if (bch2_reinherit_attrs(inode_u, dir_u)) {
216 		ret = -EXDEV;
217 		goto err;
218 	}
219 
220 	dir_u->bi_mtime = dir_u->bi_ctime = now;
221 
222 	dir_hash = bch2_hash_info_init(c, dir_u);
223 
224 	ret = bch2_dirent_create(trans, dir, &dir_hash,
225 				 mode_to_type(inode_u->bi_mode),
226 				 name, inum.inum, &dir_offset,
227 				 BCH_HASH_SET_MUST_CREATE);
228 	if (ret)
229 		goto err;
230 
231 	if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
232 		inode_u->bi_dir		= dir.inum;
233 		inode_u->bi_dir_offset	= dir_offset;
234 	}
235 
236 	ret =   bch2_inode_write(trans, &dir_iter, dir_u) ?:
237 		bch2_inode_write(trans, &inode_iter, inode_u);
238 err:
239 	bch2_trans_iter_exit(trans, &dir_iter);
240 	bch2_trans_iter_exit(trans, &inode_iter);
241 	return ret;
242 }
243 
244 int bch2_unlink_trans(struct btree_trans *trans,
245 		      subvol_inum dir,
246 		      struct bch_inode_unpacked *dir_u,
247 		      struct bch_inode_unpacked *inode_u,
248 		      const struct qstr *name,
249 		      bool deleting_snapshot)
250 {
251 	struct bch_fs *c = trans->c;
252 	struct btree_iter dir_iter = { NULL };
253 	struct btree_iter dirent_iter = { NULL };
254 	struct btree_iter inode_iter = { NULL };
255 	struct bch_hash_info dir_hash;
256 	subvol_inum inum;
257 	u64 now = bch2_current_time(c);
258 	struct bkey_s_c k;
259 	int ret;
260 
261 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
262 	if (ret)
263 		goto err;
264 
265 	dir_hash = bch2_hash_info_init(c, dir_u);
266 
267 	ret = __bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
268 					 name, &inum, BTREE_ITER_INTENT);
269 	if (ret)
270 		goto err;
271 
272 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum,
273 			      BTREE_ITER_INTENT);
274 	if (ret)
275 		goto err;
276 
277 	if (!deleting_snapshot && S_ISDIR(inode_u->bi_mode)) {
278 		ret = bch2_empty_dir_trans(trans, inum);
279 		if (ret)
280 			goto err;
281 	}
282 
283 	if (deleting_snapshot && !inode_u->bi_subvol) {
284 		ret = -BCH_ERR_ENOENT_not_subvol;
285 		goto err;
286 	}
287 
288 	if (deleting_snapshot || inode_u->bi_subvol) {
289 		ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
290 		if (ret)
291 			goto err;
292 
293 		k = bch2_btree_iter_peek_slot(&dirent_iter);
294 		ret = bkey_err(k);
295 		if (ret)
296 			goto err;
297 
298 		/*
299 		 * If we're deleting a subvolume, we need to really delete the
300 		 * dirent, not just emit a whiteout in the current snapshot:
301 		 */
302 		bch2_btree_iter_set_snapshot(&dirent_iter, k.k->p.snapshot);
303 		ret = bch2_btree_iter_traverse(&dirent_iter);
304 		if (ret)
305 			goto err;
306 	} else {
307 		bch2_inode_nlink_dec(trans, inode_u);
308 	}
309 
310 	if (inode_u->bi_dir		== dirent_iter.pos.inode &&
311 	    inode_u->bi_dir_offset	== dirent_iter.pos.offset) {
312 		inode_u->bi_dir		= 0;
313 		inode_u->bi_dir_offset	= 0;
314 	}
315 
316 	dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
317 	dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
318 
319 	ret =   bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
320 				    &dir_hash, &dirent_iter,
321 				    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
322 		bch2_inode_write(trans, &dir_iter, dir_u) ?:
323 		bch2_inode_write(trans, &inode_iter, inode_u);
324 err:
325 	bch2_trans_iter_exit(trans, &inode_iter);
326 	bch2_trans_iter_exit(trans, &dirent_iter);
327 	bch2_trans_iter_exit(trans, &dir_iter);
328 	return ret;
329 }
330 
331 bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
332 			  struct bch_inode_unpacked *src_u)
333 {
334 	u64 src, dst;
335 	unsigned id;
336 	bool ret = false;
337 
338 	for (id = 0; id < Inode_opt_nr; id++) {
339 		/* Skip attributes that were explicitly set on this inode */
340 		if (dst_u->bi_fields_set & (1 << id))
341 			continue;
342 
343 		src = bch2_inode_opt_get(src_u, id);
344 		dst = bch2_inode_opt_get(dst_u, id);
345 
346 		if (src == dst)
347 			continue;
348 
349 		bch2_inode_opt_set(dst_u, id, src);
350 		ret = true;
351 	}
352 
353 	return ret;
354 }
355 
356 int bch2_rename_trans(struct btree_trans *trans,
357 		      subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u,
358 		      subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u,
359 		      struct bch_inode_unpacked *src_inode_u,
360 		      struct bch_inode_unpacked *dst_inode_u,
361 		      const struct qstr *src_name,
362 		      const struct qstr *dst_name,
363 		      enum bch_rename_mode mode)
364 {
365 	struct bch_fs *c = trans->c;
366 	struct btree_iter src_dir_iter = { NULL };
367 	struct btree_iter dst_dir_iter = { NULL };
368 	struct btree_iter src_inode_iter = { NULL };
369 	struct btree_iter dst_inode_iter = { NULL };
370 	struct bch_hash_info src_hash, dst_hash;
371 	subvol_inum src_inum, dst_inum;
372 	u64 src_offset, dst_offset;
373 	u64 now = bch2_current_time(c);
374 	int ret;
375 
376 	ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir,
377 			      BTREE_ITER_INTENT);
378 	if (ret)
379 		goto err;
380 
381 	src_hash = bch2_hash_info_init(c, src_dir_u);
382 
383 	if (dst_dir.inum	!= src_dir.inum ||
384 	    dst_dir.subvol	!= src_dir.subvol) {
385 		ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir,
386 				      BTREE_ITER_INTENT);
387 		if (ret)
388 			goto err;
389 
390 		dst_hash = bch2_hash_info_init(c, dst_dir_u);
391 	} else {
392 		dst_dir_u = src_dir_u;
393 		dst_hash = src_hash;
394 	}
395 
396 	ret = bch2_dirent_rename(trans,
397 				 src_dir, &src_hash,
398 				 dst_dir, &dst_hash,
399 				 src_name, &src_inum, &src_offset,
400 				 dst_name, &dst_inum, &dst_offset,
401 				 mode);
402 	if (ret)
403 		goto err;
404 
405 	ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum,
406 			      BTREE_ITER_INTENT);
407 	if (ret)
408 		goto err;
409 
410 	if (dst_inum.inum) {
411 		ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum,
412 				      BTREE_ITER_INTENT);
413 		if (ret)
414 			goto err;
415 	}
416 
417 	if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
418 		src_inode_u->bi_dir		= dst_dir_u->bi_inum;
419 		src_inode_u->bi_dir_offset	= dst_offset;
420 
421 		if (mode == BCH_RENAME_EXCHANGE) {
422 			dst_inode_u->bi_dir		= src_dir_u->bi_inum;
423 			dst_inode_u->bi_dir_offset	= src_offset;
424 		}
425 
426 		if (mode == BCH_RENAME_OVERWRITE &&
427 		    dst_inode_u->bi_dir		== dst_dir_u->bi_inum &&
428 		    dst_inode_u->bi_dir_offset	== src_offset) {
429 			dst_inode_u->bi_dir		= 0;
430 			dst_inode_u->bi_dir_offset	= 0;
431 		}
432 	}
433 
434 	if (mode == BCH_RENAME_OVERWRITE) {
435 		if (S_ISDIR(src_inode_u->bi_mode) !=
436 		    S_ISDIR(dst_inode_u->bi_mode)) {
437 			ret = -ENOTDIR;
438 			goto err;
439 		}
440 
441 		if (S_ISDIR(dst_inode_u->bi_mode) &&
442 		    bch2_empty_dir_trans(trans, dst_inum)) {
443 			ret = -ENOTEMPTY;
444 			goto err;
445 		}
446 	}
447 
448 	if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) &&
449 	    S_ISDIR(src_inode_u->bi_mode)) {
450 		ret = -EXDEV;
451 		goto err;
452 	}
453 
454 	if (mode == BCH_RENAME_EXCHANGE &&
455 	    bch2_reinherit_attrs(dst_inode_u, src_dir_u) &&
456 	    S_ISDIR(dst_inode_u->bi_mode)) {
457 		ret = -EXDEV;
458 		goto err;
459 	}
460 
461 	if (is_subdir_for_nlink(src_inode_u)) {
462 		src_dir_u->bi_nlink--;
463 		dst_dir_u->bi_nlink++;
464 	}
465 
466 	if (dst_inum.inum && is_subdir_for_nlink(dst_inode_u)) {
467 		dst_dir_u->bi_nlink--;
468 		src_dir_u->bi_nlink += mode == BCH_RENAME_EXCHANGE;
469 	}
470 
471 	if (mode == BCH_RENAME_OVERWRITE)
472 		bch2_inode_nlink_dec(trans, dst_inode_u);
473 
474 	src_dir_u->bi_mtime		= now;
475 	src_dir_u->bi_ctime		= now;
476 
477 	if (src_dir.inum != dst_dir.inum) {
478 		dst_dir_u->bi_mtime	= now;
479 		dst_dir_u->bi_ctime	= now;
480 	}
481 
482 	src_inode_u->bi_ctime		= now;
483 
484 	if (dst_inum.inum)
485 		dst_inode_u->bi_ctime	= now;
486 
487 	ret =   bch2_inode_write(trans, &src_dir_iter, src_dir_u) ?:
488 		(src_dir.inum != dst_dir.inum
489 		 ? bch2_inode_write(trans, &dst_dir_iter, dst_dir_u)
490 		 : 0) ?:
491 		bch2_inode_write(trans, &src_inode_iter, src_inode_u) ?:
492 		(dst_inum.inum
493 		 ? bch2_inode_write(trans, &dst_inode_iter, dst_inode_u)
494 		 : 0);
495 err:
496 	bch2_trans_iter_exit(trans, &dst_inode_iter);
497 	bch2_trans_iter_exit(trans, &src_inode_iter);
498 	bch2_trans_iter_exit(trans, &dst_dir_iter);
499 	bch2_trans_iter_exit(trans, &src_dir_iter);
500 	return ret;
501 }
502