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
14static inline int is_subdir_for_nlink(struct bch_inode_unpacked *inode)
15{
16	return S_ISDIR(inode->bi_mode) && !inode->bi_subvol;
17}
18
19int 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					 BCH_HASH_SET_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);
179err:
180	bch2_trans_iter_exit(trans, &inode_iter);
181	bch2_trans_iter_exit(trans, &dir_iter);
182	return ret;
183}
184
185int 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		goto err;
204
205	inode_u->bi_ctime = now;
206	ret = bch2_inode_nlink_inc(inode_u);
207	if (ret)
208		return ret;
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				 BCH_HASH_SET_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);
235err:
236	bch2_trans_iter_exit(trans, &dir_iter);
237	bch2_trans_iter_exit(trans, &inode_iter);
238	return ret;
239}
240
241int 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);
328err:
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
335bool 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
360static 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
376int 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);
543err:
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