xref: /linux/fs/bcachefs/fs-common.c (revision 962ad1a76669443126c6531352380f56d6e5d7d2)
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 	dir_u->bi_mtime = dir_u->bi_ctime = now;
216 
217 	dir_hash = bch2_hash_info_init(c, dir_u);
218 
219 	ret = bch2_dirent_create(trans, dir, &dir_hash,
220 				 mode_to_type(inode_u->bi_mode),
221 				 name, inum.inum, &dir_offset,
222 				 BCH_HASH_SET_MUST_CREATE);
223 	if (ret)
224 		goto err;
225 
226 	if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
227 		inode_u->bi_dir		= dir.inum;
228 		inode_u->bi_dir_offset	= dir_offset;
229 	}
230 
231 	ret =   bch2_inode_write(trans, &dir_iter, dir_u) ?:
232 		bch2_inode_write(trans, &inode_iter, inode_u);
233 err:
234 	bch2_trans_iter_exit(trans, &dir_iter);
235 	bch2_trans_iter_exit(trans, &inode_iter);
236 	return ret;
237 }
238 
239 int bch2_unlink_trans(struct btree_trans *trans,
240 		      subvol_inum dir,
241 		      struct bch_inode_unpacked *dir_u,
242 		      struct bch_inode_unpacked *inode_u,
243 		      const struct qstr *name,
244 		      bool deleting_snapshot)
245 {
246 	struct bch_fs *c = trans->c;
247 	struct btree_iter dir_iter = { NULL };
248 	struct btree_iter dirent_iter = { NULL };
249 	struct btree_iter inode_iter = { NULL };
250 	struct bch_hash_info dir_hash;
251 	subvol_inum inum;
252 	u64 now = bch2_current_time(c);
253 	struct bkey_s_c k;
254 	int ret;
255 
256 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
257 	if (ret)
258 		goto err;
259 
260 	dir_hash = bch2_hash_info_init(c, dir_u);
261 
262 	ret = __bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
263 					 name, &inum, BTREE_ITER_INTENT);
264 	if (ret)
265 		goto err;
266 
267 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum,
268 			      BTREE_ITER_INTENT);
269 	if (ret)
270 		goto err;
271 
272 	if (!deleting_snapshot && S_ISDIR(inode_u->bi_mode)) {
273 		ret = bch2_empty_dir_trans(trans, inum);
274 		if (ret)
275 			goto err;
276 	}
277 
278 	if (deleting_snapshot && !inode_u->bi_subvol) {
279 		ret = -ENOENT;
280 		goto err;
281 	}
282 
283 	if (deleting_snapshot || inode_u->bi_subvol) {
284 		ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
285 		if (ret)
286 			goto err;
287 
288 		k = bch2_btree_iter_peek_slot(&dirent_iter);
289 		ret = bkey_err(k);
290 		if (ret)
291 			goto err;
292 
293 		/*
294 		 * If we're deleting a subvolume, we need to really delete the
295 		 * dirent, not just emit a whiteout in the current snapshot:
296 		 */
297 		bch2_btree_iter_set_snapshot(&dirent_iter, k.k->p.snapshot);
298 		ret = bch2_btree_iter_traverse(&dirent_iter);
299 		if (ret)
300 			goto err;
301 	} else {
302 		bch2_inode_nlink_dec(trans, inode_u);
303 	}
304 
305 	if (inode_u->bi_dir		== dirent_iter.pos.inode &&
306 	    inode_u->bi_dir_offset	== dirent_iter.pos.offset) {
307 		inode_u->bi_dir		= 0;
308 		inode_u->bi_dir_offset	= 0;
309 	}
310 
311 	dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
312 	dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
313 
314 	ret =   bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
315 				    &dir_hash, &dirent_iter,
316 				    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
317 		bch2_inode_write(trans, &dir_iter, dir_u) ?:
318 		bch2_inode_write(trans, &inode_iter, inode_u);
319 err:
320 	bch2_trans_iter_exit(trans, &inode_iter);
321 	bch2_trans_iter_exit(trans, &dirent_iter);
322 	bch2_trans_iter_exit(trans, &dir_iter);
323 	return ret;
324 }
325 
326 bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
327 			  struct bch_inode_unpacked *src_u)
328 {
329 	u64 src, dst;
330 	unsigned id;
331 	bool ret = false;
332 
333 	for (id = 0; id < Inode_opt_nr; id++) {
334 		/* Skip attributes that were explicitly set on this inode */
335 		if (dst_u->bi_fields_set & (1 << id))
336 			continue;
337 
338 		src = bch2_inode_opt_get(src_u, id);
339 		dst = bch2_inode_opt_get(dst_u, id);
340 
341 		if (src == dst)
342 			continue;
343 
344 		bch2_inode_opt_set(dst_u, id, src);
345 		ret = true;
346 	}
347 
348 	return ret;
349 }
350 
351 int bch2_rename_trans(struct btree_trans *trans,
352 		      subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u,
353 		      subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u,
354 		      struct bch_inode_unpacked *src_inode_u,
355 		      struct bch_inode_unpacked *dst_inode_u,
356 		      const struct qstr *src_name,
357 		      const struct qstr *dst_name,
358 		      enum bch_rename_mode mode)
359 {
360 	struct bch_fs *c = trans->c;
361 	struct btree_iter src_dir_iter = { NULL };
362 	struct btree_iter dst_dir_iter = { NULL };
363 	struct btree_iter src_inode_iter = { NULL };
364 	struct btree_iter dst_inode_iter = { NULL };
365 	struct bch_hash_info src_hash, dst_hash;
366 	subvol_inum src_inum, dst_inum;
367 	u64 src_offset, dst_offset;
368 	u64 now = bch2_current_time(c);
369 	int ret;
370 
371 	ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir,
372 			      BTREE_ITER_INTENT);
373 	if (ret)
374 		goto err;
375 
376 	src_hash = bch2_hash_info_init(c, src_dir_u);
377 
378 	if (dst_dir.inum	!= src_dir.inum ||
379 	    dst_dir.subvol	!= src_dir.subvol) {
380 		ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir,
381 				      BTREE_ITER_INTENT);
382 		if (ret)
383 			goto err;
384 
385 		dst_hash = bch2_hash_info_init(c, dst_dir_u);
386 	} else {
387 		dst_dir_u = src_dir_u;
388 		dst_hash = src_hash;
389 	}
390 
391 	ret = bch2_dirent_rename(trans,
392 				 src_dir, &src_hash,
393 				 dst_dir, &dst_hash,
394 				 src_name, &src_inum, &src_offset,
395 				 dst_name, &dst_inum, &dst_offset,
396 				 mode);
397 	if (ret)
398 		goto err;
399 
400 	ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum,
401 			      BTREE_ITER_INTENT);
402 	if (ret)
403 		goto err;
404 
405 	if (dst_inum.inum) {
406 		ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum,
407 				      BTREE_ITER_INTENT);
408 		if (ret)
409 			goto err;
410 	}
411 
412 	if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
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 
429 	if (mode == BCH_RENAME_OVERWRITE) {
430 		if (S_ISDIR(src_inode_u->bi_mode) !=
431 		    S_ISDIR(dst_inode_u->bi_mode)) {
432 			ret = -ENOTDIR;
433 			goto err;
434 		}
435 
436 		if (S_ISDIR(dst_inode_u->bi_mode) &&
437 		    bch2_empty_dir_trans(trans, dst_inum)) {
438 			ret = -ENOTEMPTY;
439 			goto err;
440 		}
441 	}
442 
443 	if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) &&
444 	    S_ISDIR(src_inode_u->bi_mode)) {
445 		ret = -EXDEV;
446 		goto err;
447 	}
448 
449 	if (mode == BCH_RENAME_EXCHANGE &&
450 	    bch2_reinherit_attrs(dst_inode_u, src_dir_u) &&
451 	    S_ISDIR(dst_inode_u->bi_mode)) {
452 		ret = -EXDEV;
453 		goto err;
454 	}
455 
456 	if (is_subdir_for_nlink(src_inode_u)) {
457 		src_dir_u->bi_nlink--;
458 		dst_dir_u->bi_nlink++;
459 	}
460 
461 	if (dst_inum.inum && is_subdir_for_nlink(dst_inode_u)) {
462 		dst_dir_u->bi_nlink--;
463 		src_dir_u->bi_nlink += mode == BCH_RENAME_EXCHANGE;
464 	}
465 
466 	if (mode == BCH_RENAME_OVERWRITE)
467 		bch2_inode_nlink_dec(trans, dst_inode_u);
468 
469 	src_dir_u->bi_mtime		= now;
470 	src_dir_u->bi_ctime		= now;
471 
472 	if (src_dir.inum != dst_dir.inum) {
473 		dst_dir_u->bi_mtime	= now;
474 		dst_dir_u->bi_ctime	= now;
475 	}
476 
477 	src_inode_u->bi_ctime		= now;
478 
479 	if (dst_inum.inum)
480 		dst_inode_u->bi_ctime	= now;
481 
482 	ret =   bch2_inode_write(trans, &src_dir_iter, src_dir_u) ?:
483 		(src_dir.inum != dst_dir.inum
484 		 ? bch2_inode_write(trans, &dst_dir_iter, dst_dir_u)
485 		 : 0 ) ?:
486 		bch2_inode_write(trans, &src_inode_iter, src_inode_u) ?:
487 		(dst_inum.inum
488 		 ? bch2_inode_write(trans, &dst_inode_iter, dst_inode_u)
489 		 : 0 );
490 err:
491 	bch2_trans_iter_exit(trans, &dst_inode_iter);
492 	bch2_trans_iter_exit(trans, &src_inode_iter);
493 	bch2_trans_iter_exit(trans, &dst_dir_iter);
494 	bch2_trans_iter_exit(trans, &src_dir_iter);
495 	return ret;
496 }
497