xref: /linux/fs/bcachefs/fs-common.c (revision 2027875bd8318171159495c948461eae2f84936d)
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 	bch2_inode_nlink_inc(inode_u);
208 
209 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
210 	if (ret)
211 		goto err;
212 
213 	dir_u->bi_mtime = dir_u->bi_ctime = now;
214 
215 	dir_hash = bch2_hash_info_init(c, dir_u);
216 
217 	ret = bch2_dirent_create(trans, dir, &dir_hash,
218 				 mode_to_type(inode_u->bi_mode),
219 				 name, inum.inum, &dir_offset,
220 				 BCH_HASH_SET_MUST_CREATE);
221 	if (ret)
222 		goto err;
223 
224 	if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
225 		inode_u->bi_dir		= dir.inum;
226 		inode_u->bi_dir_offset	= dir_offset;
227 	}
228 
229 	ret =   bch2_inode_write(trans, &dir_iter, dir_u) ?:
230 		bch2_inode_write(trans, &inode_iter, inode_u);
231 err:
232 	bch2_trans_iter_exit(trans, &dir_iter);
233 	bch2_trans_iter_exit(trans, &inode_iter);
234 	return ret;
235 }
236 
237 int bch2_unlink_trans(struct btree_trans *trans,
238 		      subvol_inum dir,
239 		      struct bch_inode_unpacked *dir_u,
240 		      struct bch_inode_unpacked *inode_u,
241 		      const struct qstr *name,
242 		      bool deleting_snapshot)
243 {
244 	struct bch_fs *c = trans->c;
245 	struct btree_iter dir_iter = { NULL };
246 	struct btree_iter dirent_iter = { NULL };
247 	struct btree_iter inode_iter = { NULL };
248 	struct bch_hash_info dir_hash;
249 	subvol_inum inum;
250 	u64 now = bch2_current_time(c);
251 	struct bkey_s_c k;
252 	int ret;
253 
254 	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
255 	if (ret)
256 		goto err;
257 
258 	dir_hash = bch2_hash_info_init(c, dir_u);
259 
260 	ret = __bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
261 					 name, &inum, BTREE_ITER_INTENT);
262 	if (ret)
263 		goto err;
264 
265 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum,
266 			      BTREE_ITER_INTENT);
267 	if (ret)
268 		goto err;
269 
270 	if (!deleting_snapshot && S_ISDIR(inode_u->bi_mode)) {
271 		ret = bch2_empty_dir_trans(trans, inum);
272 		if (ret)
273 			goto err;
274 	}
275 
276 	if (deleting_snapshot && !inode_u->bi_subvol) {
277 		ret = -ENOENT;
278 		goto err;
279 	}
280 
281 	if (deleting_snapshot || inode_u->bi_subvol) {
282 		ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
283 		if (ret)
284 			goto err;
285 
286 		k = bch2_btree_iter_peek_slot(&dirent_iter);
287 		ret = bkey_err(k);
288 		if (ret)
289 			goto err;
290 
291 		/*
292 		 * If we're deleting a subvolume, we need to really delete the
293 		 * dirent, not just emit a whiteout in the current snapshot:
294 		 */
295 		bch2_btree_iter_set_snapshot(&dirent_iter, k.k->p.snapshot);
296 		ret = bch2_btree_iter_traverse(&dirent_iter);
297 		if (ret)
298 			goto err;
299 	} else {
300 		bch2_inode_nlink_dec(inode_u);
301 	}
302 
303 	if (inode_u->bi_dir		== dirent_iter.pos.inode &&
304 	    inode_u->bi_dir_offset	== dirent_iter.pos.offset) {
305 		inode_u->bi_dir		= 0;
306 		inode_u->bi_dir_offset	= 0;
307 	}
308 
309 	dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
310 	dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
311 
312 	ret =   bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
313 				    &dir_hash, &dirent_iter,
314 				    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
315 		bch2_inode_write(trans, &dir_iter, dir_u) ?:
316 		bch2_inode_write(trans, &inode_iter, inode_u);
317 err:
318 	bch2_trans_iter_exit(trans, &inode_iter);
319 	bch2_trans_iter_exit(trans, &dirent_iter);
320 	bch2_trans_iter_exit(trans, &dir_iter);
321 	return ret;
322 }
323 
324 bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u,
325 			  struct bch_inode_unpacked *src_u)
326 {
327 	u64 src, dst;
328 	unsigned id;
329 	bool ret = false;
330 
331 	for (id = 0; id < Inode_opt_nr; id++) {
332 		if (dst_u->bi_fields_set & (1 << id))
333 			continue;
334 
335 		src = bch2_inode_opt_get(src_u, id);
336 		dst = bch2_inode_opt_get(dst_u, id);
337 
338 		if (src == dst)
339 			continue;
340 
341 		bch2_inode_opt_set(dst_u, id, src);
342 		ret = true;
343 	}
344 
345 	return ret;
346 }
347 
348 int bch2_rename_trans(struct btree_trans *trans,
349 		      subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u,
350 		      subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u,
351 		      struct bch_inode_unpacked *src_inode_u,
352 		      struct bch_inode_unpacked *dst_inode_u,
353 		      const struct qstr *src_name,
354 		      const struct qstr *dst_name,
355 		      enum bch_rename_mode mode)
356 {
357 	struct bch_fs *c = trans->c;
358 	struct btree_iter src_dir_iter = { NULL };
359 	struct btree_iter dst_dir_iter = { NULL };
360 	struct btree_iter src_inode_iter = { NULL };
361 	struct btree_iter dst_inode_iter = { NULL };
362 	struct bch_hash_info src_hash, dst_hash;
363 	subvol_inum src_inum, dst_inum;
364 	u64 src_offset, dst_offset;
365 	u64 now = bch2_current_time(c);
366 	int ret;
367 
368 	ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir,
369 			      BTREE_ITER_INTENT);
370 	if (ret)
371 		goto err;
372 
373 	src_hash = bch2_hash_info_init(c, src_dir_u);
374 
375 	if (dst_dir.inum	!= src_dir.inum ||
376 	    dst_dir.subvol	!= src_dir.subvol) {
377 		ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir,
378 				      BTREE_ITER_INTENT);
379 		if (ret)
380 			goto err;
381 
382 		dst_hash = bch2_hash_info_init(c, dst_dir_u);
383 	} else {
384 		dst_dir_u = src_dir_u;
385 		dst_hash = src_hash;
386 	}
387 
388 	ret = bch2_dirent_rename(trans,
389 				 src_dir, &src_hash,
390 				 dst_dir, &dst_hash,
391 				 src_name, &src_inum, &src_offset,
392 				 dst_name, &dst_inum, &dst_offset,
393 				 mode);
394 	if (ret)
395 		goto err;
396 
397 	ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum,
398 			      BTREE_ITER_INTENT);
399 	if (ret)
400 		goto err;
401 
402 	if (dst_inum.inum) {
403 		ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum,
404 				      BTREE_ITER_INTENT);
405 		if (ret)
406 			goto err;
407 	}
408 
409 	if (c->sb.version >= bcachefs_metadata_version_inode_backpointers) {
410 		src_inode_u->bi_dir		= dst_dir_u->bi_inum;
411 		src_inode_u->bi_dir_offset	= dst_offset;
412 
413 		if (mode == BCH_RENAME_EXCHANGE) {
414 			dst_inode_u->bi_dir		= src_dir_u->bi_inum;
415 			dst_inode_u->bi_dir_offset	= src_offset;
416 		}
417 
418 		if (mode == BCH_RENAME_OVERWRITE &&
419 		    dst_inode_u->bi_dir		== dst_dir_u->bi_inum &&
420 		    dst_inode_u->bi_dir_offset	== src_offset) {
421 			dst_inode_u->bi_dir		= 0;
422 			dst_inode_u->bi_dir_offset	= 0;
423 		}
424 	}
425 
426 	if (mode == BCH_RENAME_OVERWRITE) {
427 		if (S_ISDIR(src_inode_u->bi_mode) !=
428 		    S_ISDIR(dst_inode_u->bi_mode)) {
429 			ret = -ENOTDIR;
430 			goto err;
431 		}
432 
433 		if (S_ISDIR(dst_inode_u->bi_mode) &&
434 		    bch2_empty_dir_trans(trans, dst_inum)) {
435 			ret = -ENOTEMPTY;
436 			goto err;
437 		}
438 	}
439 
440 	if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) &&
441 	    S_ISDIR(src_inode_u->bi_mode)) {
442 		ret = -EXDEV;
443 		goto err;
444 	}
445 
446 	if (mode == BCH_RENAME_EXCHANGE &&
447 	    bch2_reinherit_attrs(dst_inode_u, src_dir_u) &&
448 	    S_ISDIR(dst_inode_u->bi_mode)) {
449 		ret = -EXDEV;
450 		goto err;
451 	}
452 
453 	if (is_subdir_for_nlink(src_inode_u)) {
454 		src_dir_u->bi_nlink--;
455 		dst_dir_u->bi_nlink++;
456 	}
457 
458 	if (dst_inum.inum && is_subdir_for_nlink(dst_inode_u)) {
459 		dst_dir_u->bi_nlink--;
460 		src_dir_u->bi_nlink += mode == BCH_RENAME_EXCHANGE;
461 	}
462 
463 	if (mode == BCH_RENAME_OVERWRITE)
464 		bch2_inode_nlink_dec(dst_inode_u);
465 
466 	src_dir_u->bi_mtime		= now;
467 	src_dir_u->bi_ctime		= now;
468 
469 	if (src_dir.inum != dst_dir.inum) {
470 		dst_dir_u->bi_mtime	= now;
471 		dst_dir_u->bi_ctime	= now;
472 	}
473 
474 	src_inode_u->bi_ctime		= now;
475 
476 	if (dst_inum.inum)
477 		dst_inode_u->bi_ctime	= now;
478 
479 	ret =   bch2_inode_write(trans, &src_dir_iter, src_dir_u) ?:
480 		(src_dir.inum != dst_dir.inum
481 		 ? bch2_inode_write(trans, &dst_dir_iter, dst_dir_u)
482 		 : 0 ) ?:
483 		bch2_inode_write(trans, &src_inode_iter, src_inode_u) ?:
484 		(dst_inum.inum
485 		 ? bch2_inode_write(trans, &dst_inode_iter, dst_inode_u)
486 		 : 0 );
487 err:
488 	bch2_trans_iter_exit(trans, &dst_inode_iter);
489 	bch2_trans_iter_exit(trans, &src_inode_iter);
490 	bch2_trans_iter_exit(trans, &dst_dir_iter);
491 	bch2_trans_iter_exit(trans, &src_dir_iter);
492 	return ret;
493 }
494