xref: /linux/fs/bcachefs/fs-common.c (revision c4101e55974cc7d835fbd2d8e01553a3f61e9e75)
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 		new_inode->bi_dir		= dir_u->bi_inum;
170 		new_inode->bi_dir_offset	= dir_offset;
171 	}
172 
173 	inode_iter.flags &= ~BTREE_ITER_ALL_SNAPSHOTS;
174 	bch2_btree_iter_set_snapshot(&inode_iter, snapshot);
175 
176 	ret   = bch2_btree_iter_traverse(&inode_iter) ?:
177 		bch2_inode_write(trans, &inode_iter, new_inode);
178 err:
179 	bch2_trans_iter_exit(trans, &inode_iter);
180 	bch2_trans_iter_exit(trans, &dir_iter);
181 	return ret;
182 }
183 
184 int bch2_link_trans(struct btree_trans *trans,
185 		    subvol_inum dir,  struct bch_inode_unpacked *dir_u,
186 		    subvol_inum inum, struct bch_inode_unpacked *inode_u,
187 		    const struct qstr *name)
188 {
189 	struct bch_fs *c = trans->c;
190 	struct btree_iter dir_iter = { NULL };
191 	struct btree_iter inode_iter = { NULL };
192 	struct bch_hash_info dir_hash;
193 	u64 now = bch2_current_time(c);
194 	u64 dir_offset = 0;
195 	int ret;
196 
197 	if (dir.subvol != inum.subvol)
198 		return -EXDEV;
199 
200 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_INTENT);
201 	if (ret)
202 		goto err;
203 
204 	inode_u->bi_ctime = now;
205 	ret = bch2_inode_nlink_inc(inode_u);
206 	if (ret)
207 		return ret;
208 
209 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
210 	if (ret)
211 		goto err;
212 
213 	if (bch2_reinherit_attrs(inode_u, dir_u)) {
214 		ret = -EXDEV;
215 		goto err;
216 	}
217 
218 	dir_u->bi_mtime = dir_u->bi_ctime = now;
219 
220 	dir_hash = bch2_hash_info_init(c, dir_u);
221 
222 	ret = bch2_dirent_create(trans, dir, &dir_hash,
223 				 mode_to_type(inode_u->bi_mode),
224 				 name, inum.inum, &dir_offset,
225 				 BCH_HASH_SET_MUST_CREATE);
226 	if (ret)
227 		goto err;
228 
229 	inode_u->bi_dir		= dir.inum;
230 	inode_u->bi_dir_offset	= dir_offset;
231 
232 	ret =   bch2_inode_write(trans, &dir_iter, dir_u) ?:
233 		bch2_inode_write(trans, &inode_iter, inode_u);
234 err:
235 	bch2_trans_iter_exit(trans, &dir_iter);
236 	bch2_trans_iter_exit(trans, &inode_iter);
237 	return ret;
238 }
239 
240 int bch2_unlink_trans(struct btree_trans *trans,
241 		      subvol_inum dir,
242 		      struct bch_inode_unpacked *dir_u,
243 		      struct bch_inode_unpacked *inode_u,
244 		      const struct qstr *name,
245 		      bool deleting_snapshot)
246 {
247 	struct bch_fs *c = trans->c;
248 	struct btree_iter dir_iter = { NULL };
249 	struct btree_iter dirent_iter = { NULL };
250 	struct btree_iter inode_iter = { NULL };
251 	struct bch_hash_info dir_hash;
252 	subvol_inum inum;
253 	u64 now = bch2_current_time(c);
254 	struct bkey_s_c k;
255 	int ret;
256 
257 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
258 	if (ret)
259 		goto err;
260 
261 	dir_hash = bch2_hash_info_init(c, dir_u);
262 
263 	ret = __bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
264 					 name, &inum, BTREE_ITER_INTENT);
265 	if (ret)
266 		goto err;
267 
268 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum,
269 			      BTREE_ITER_INTENT);
270 	if (ret)
271 		goto err;
272 
273 	if (!deleting_snapshot && S_ISDIR(inode_u->bi_mode)) {
274 		ret = bch2_empty_dir_trans(trans, inum);
275 		if (ret)
276 			goto err;
277 	}
278 
279 	if (deleting_snapshot && !inode_u->bi_subvol) {
280 		ret = -BCH_ERR_ENOENT_not_subvol;
281 		goto err;
282 	}
283 
284 	if (deleting_snapshot || inode_u->bi_subvol) {
285 		ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
286 		if (ret)
287 			goto err;
288 
289 		k = bch2_btree_iter_peek_slot(&dirent_iter);
290 		ret = bkey_err(k);
291 		if (ret)
292 			goto err;
293 
294 		/*
295 		 * If we're deleting a subvolume, we need to really delete the
296 		 * dirent, not just emit a whiteout in the current snapshot:
297 		 */
298 		bch2_btree_iter_set_snapshot(&dirent_iter, k.k->p.snapshot);
299 		ret = bch2_btree_iter_traverse(&dirent_iter);
300 		if (ret)
301 			goto err;
302 	} else {
303 		bch2_inode_nlink_dec(trans, inode_u);
304 	}
305 
306 	if (inode_u->bi_dir		== dirent_iter.pos.inode &&
307 	    inode_u->bi_dir_offset	== dirent_iter.pos.offset) {
308 		inode_u->bi_dir		= 0;
309 		inode_u->bi_dir_offset	= 0;
310 	}
311 
312 	dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
313 	dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
314 
315 	ret =   bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
316 				    &dir_hash, &dirent_iter,
317 				    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
318 		bch2_inode_write(trans, &dir_iter, dir_u) ?:
319 		bch2_inode_write(trans, &inode_iter, inode_u);
320 err:
321 	bch2_trans_iter_exit(trans, &inode_iter);
322 	bch2_trans_iter_exit(trans, &dirent_iter);
323 	bch2_trans_iter_exit(trans, &dir_iter);
324 	return ret;
325 }
326 
327 bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
328 			  struct bch_inode_unpacked *src_u)
329 {
330 	u64 src, dst;
331 	unsigned id;
332 	bool ret = false;
333 
334 	for (id = 0; id < Inode_opt_nr; id++) {
335 		/* Skip attributes that were explicitly set on this inode */
336 		if (dst_u->bi_fields_set & (1 << id))
337 			continue;
338 
339 		src = bch2_inode_opt_get(src_u, id);
340 		dst = bch2_inode_opt_get(dst_u, id);
341 
342 		if (src == dst)
343 			continue;
344 
345 		bch2_inode_opt_set(dst_u, id, src);
346 		ret = true;
347 	}
348 
349 	return ret;
350 }
351 
352 int bch2_rename_trans(struct btree_trans *trans,
353 		      subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u,
354 		      subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u,
355 		      struct bch_inode_unpacked *src_inode_u,
356 		      struct bch_inode_unpacked *dst_inode_u,
357 		      const struct qstr *src_name,
358 		      const struct qstr *dst_name,
359 		      enum bch_rename_mode mode)
360 {
361 	struct bch_fs *c = trans->c;
362 	struct btree_iter src_dir_iter = { NULL };
363 	struct btree_iter dst_dir_iter = { NULL };
364 	struct btree_iter src_inode_iter = { NULL };
365 	struct btree_iter dst_inode_iter = { NULL };
366 	struct bch_hash_info src_hash, dst_hash;
367 	subvol_inum src_inum, dst_inum;
368 	u64 src_offset, dst_offset;
369 	u64 now = bch2_current_time(c);
370 	int ret;
371 
372 	ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir,
373 			      BTREE_ITER_INTENT);
374 	if (ret)
375 		goto err;
376 
377 	src_hash = bch2_hash_info_init(c, src_dir_u);
378 
379 	if (dst_dir.inum	!= src_dir.inum ||
380 	    dst_dir.subvol	!= src_dir.subvol) {
381 		ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir,
382 				      BTREE_ITER_INTENT);
383 		if (ret)
384 			goto err;
385 
386 		dst_hash = bch2_hash_info_init(c, dst_dir_u);
387 	} else {
388 		dst_dir_u = src_dir_u;
389 		dst_hash = src_hash;
390 	}
391 
392 	ret = bch2_dirent_rename(trans,
393 				 src_dir, &src_hash,
394 				 dst_dir, &dst_hash,
395 				 src_name, &src_inum, &src_offset,
396 				 dst_name, &dst_inum, &dst_offset,
397 				 mode);
398 	if (ret)
399 		goto err;
400 
401 	ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum,
402 			      BTREE_ITER_INTENT);
403 	if (ret)
404 		goto err;
405 
406 	if (dst_inum.inum) {
407 		ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum,
408 				      BTREE_ITER_INTENT);
409 		if (ret)
410 			goto err;
411 	}
412 
413 	src_inode_u->bi_dir		= dst_dir_u->bi_inum;
414 	src_inode_u->bi_dir_offset	= dst_offset;
415 
416 	if (mode == BCH_RENAME_EXCHANGE) {
417 		dst_inode_u->bi_dir		= src_dir_u->bi_inum;
418 		dst_inode_u->bi_dir_offset	= src_offset;
419 	}
420 
421 	if (mode == BCH_RENAME_OVERWRITE &&
422 	    dst_inode_u->bi_dir		== dst_dir_u->bi_inum &&
423 	    dst_inode_u->bi_dir_offset	== src_offset) {
424 		dst_inode_u->bi_dir		= 0;
425 		dst_inode_u->bi_dir_offset	= 0;
426 	}
427 
428 	if (mode == BCH_RENAME_OVERWRITE) {
429 		if (S_ISDIR(src_inode_u->bi_mode) !=
430 		    S_ISDIR(dst_inode_u->bi_mode)) {
431 			ret = -ENOTDIR;
432 			goto err;
433 		}
434 
435 		if (S_ISDIR(dst_inode_u->bi_mode) &&
436 		    bch2_empty_dir_trans(trans, dst_inum)) {
437 			ret = -ENOTEMPTY;
438 			goto err;
439 		}
440 	}
441 
442 	if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) &&
443 	    S_ISDIR(src_inode_u->bi_mode)) {
444 		ret = -EXDEV;
445 		goto err;
446 	}
447 
448 	if (mode == BCH_RENAME_EXCHANGE &&
449 	    bch2_reinherit_attrs(dst_inode_u, src_dir_u) &&
450 	    S_ISDIR(dst_inode_u->bi_mode)) {
451 		ret = -EXDEV;
452 		goto err;
453 	}
454 
455 	if (is_subdir_for_nlink(src_inode_u)) {
456 		src_dir_u->bi_nlink--;
457 		dst_dir_u->bi_nlink++;
458 	}
459 
460 	if (dst_inum.inum && is_subdir_for_nlink(dst_inode_u)) {
461 		dst_dir_u->bi_nlink--;
462 		src_dir_u->bi_nlink += mode == BCH_RENAME_EXCHANGE;
463 	}
464 
465 	if (mode == BCH_RENAME_OVERWRITE)
466 		bch2_inode_nlink_dec(trans, dst_inode_u);
467 
468 	src_dir_u->bi_mtime		= now;
469 	src_dir_u->bi_ctime		= now;
470 
471 	if (src_dir.inum != dst_dir.inum) {
472 		dst_dir_u->bi_mtime	= now;
473 		dst_dir_u->bi_ctime	= now;
474 	}
475 
476 	src_inode_u->bi_ctime		= now;
477 
478 	if (dst_inum.inum)
479 		dst_inode_u->bi_ctime	= now;
480 
481 	ret =   bch2_inode_write(trans, &src_dir_iter, src_dir_u) ?:
482 		(src_dir.inum != dst_dir.inum
483 		 ? bch2_inode_write(trans, &dst_dir_iter, dst_dir_u)
484 		 : 0) ?:
485 		bch2_inode_write(trans, &src_inode_iter, src_inode_u) ?:
486 		(dst_inum.inum
487 		 ? bch2_inode_write(trans, &dst_inode_iter, dst_inode_u)
488 		 : 0);
489 err:
490 	bch2_trans_iter_exit(trans, &dst_inode_iter);
491 	bch2_trans_iter_exit(trans, &src_inode_iter);
492 	bch2_trans_iter_exit(trans, &dst_dir_iter);
493 	bch2_trans_iter_exit(trans, &src_dir_iter);
494 	return ret;
495 }
496