1// SPDX-License-Identifier: GPL-2.0
2
3#include "bcachefs.h"
4#include "acl.h"
5#include "bkey_methods.h"
6#include "btree_update.h"
7#include "extents.h"
8#include "fs.h"
9#include "rebalance.h"
10#include "str_hash.h"
11#include "xattr.h"
12
13#include <linux/dcache.h>
14#include <linux/posix_acl_xattr.h>
15#include <linux/xattr.h>
16
17static const struct xattr_handler *bch2_xattr_type_to_handler(unsigned);
18
19static u64 bch2_xattr_hash(const struct bch_hash_info *info,
20			  const struct xattr_search_key *key)
21{
22	struct bch_str_hash_ctx ctx;
23
24	bch2_str_hash_init(&ctx, info);
25	bch2_str_hash_update(&ctx, info, &key->type, sizeof(key->type));
26	bch2_str_hash_update(&ctx, info, key->name.name, key->name.len);
27
28	return bch2_str_hash_end(&ctx, info);
29}
30
31static u64 xattr_hash_key(const struct bch_hash_info *info, const void *key)
32{
33	return bch2_xattr_hash(info, key);
34}
35
36static u64 xattr_hash_bkey(const struct bch_hash_info *info, struct bkey_s_c k)
37{
38	struct bkey_s_c_xattr x = bkey_s_c_to_xattr(k);
39
40	return bch2_xattr_hash(info,
41		 &X_SEARCH(x.v->x_type, x.v->x_name, x.v->x_name_len));
42}
43
44static bool xattr_cmp_key(struct bkey_s_c _l, const void *_r)
45{
46	struct bkey_s_c_xattr l = bkey_s_c_to_xattr(_l);
47	const struct xattr_search_key *r = _r;
48
49	return l.v->x_type != r->type ||
50		l.v->x_name_len != r->name.len ||
51		memcmp(l.v->x_name, r->name.name, r->name.len);
52}
53
54static bool xattr_cmp_bkey(struct bkey_s_c _l, struct bkey_s_c _r)
55{
56	struct bkey_s_c_xattr l = bkey_s_c_to_xattr(_l);
57	struct bkey_s_c_xattr r = bkey_s_c_to_xattr(_r);
58
59	return l.v->x_type != r.v->x_type ||
60		l.v->x_name_len != r.v->x_name_len ||
61		memcmp(l.v->x_name, r.v->x_name, r.v->x_name_len);
62}
63
64const struct bch_hash_desc bch2_xattr_hash_desc = {
65	.btree_id	= BTREE_ID_xattrs,
66	.key_type	= KEY_TYPE_xattr,
67	.hash_key	= xattr_hash_key,
68	.hash_bkey	= xattr_hash_bkey,
69	.cmp_key	= xattr_cmp_key,
70	.cmp_bkey	= xattr_cmp_bkey,
71};
72
73int bch2_xattr_invalid(struct bch_fs *c, struct bkey_s_c k,
74		       enum bkey_invalid_flags flags,
75		       struct printbuf *err)
76{
77	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
78	unsigned val_u64s = xattr_val_u64s(xattr.v->x_name_len,
79					   le16_to_cpu(xattr.v->x_val_len));
80	int ret = 0;
81
82	bkey_fsck_err_on(bkey_val_u64s(k.k) < val_u64s, c, err,
83			 xattr_val_size_too_small,
84			 "value too small (%zu < %u)",
85			 bkey_val_u64s(k.k), val_u64s);
86
87	/* XXX why +4 ? */
88	val_u64s = xattr_val_u64s(xattr.v->x_name_len,
89				  le16_to_cpu(xattr.v->x_val_len) + 4);
90
91	bkey_fsck_err_on(bkey_val_u64s(k.k) > val_u64s, c, err,
92			 xattr_val_size_too_big,
93			 "value too big (%zu > %u)",
94			 bkey_val_u64s(k.k), val_u64s);
95
96	bkey_fsck_err_on(!bch2_xattr_type_to_handler(xattr.v->x_type), c, err,
97			 xattr_invalid_type,
98			 "invalid type (%u)", xattr.v->x_type);
99
100	bkey_fsck_err_on(memchr(xattr.v->x_name, '\0', xattr.v->x_name_len), c, err,
101			 xattr_name_invalid_chars,
102			 "xattr name has invalid characters");
103fsck_err:
104	return ret;
105}
106
107void bch2_xattr_to_text(struct printbuf *out, struct bch_fs *c,
108			struct bkey_s_c k)
109{
110	const struct xattr_handler *handler;
111	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
112
113	handler = bch2_xattr_type_to_handler(xattr.v->x_type);
114	if (handler && handler->prefix)
115		prt_printf(out, "%s", handler->prefix);
116	else if (handler)
117		prt_printf(out, "(type %u)", xattr.v->x_type);
118	else
119		prt_printf(out, "(unknown type %u)", xattr.v->x_type);
120
121	prt_printf(out, "%.*s:%.*s",
122	       xattr.v->x_name_len,
123	       xattr.v->x_name,
124	       le16_to_cpu(xattr.v->x_val_len),
125	       (char *) xattr_val(xattr.v));
126
127	if (xattr.v->x_type == KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS ||
128	    xattr.v->x_type == KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT) {
129		prt_char(out, ' ');
130		bch2_acl_to_text(out, xattr_val(xattr.v),
131				 le16_to_cpu(xattr.v->x_val_len));
132	}
133}
134
135static int bch2_xattr_get_trans(struct btree_trans *trans, struct bch_inode_info *inode,
136				const char *name, void *buffer, size_t size, int type)
137{
138	struct bch_hash_info hash = bch2_hash_info_init(trans->c, &inode->ei_inode);
139	struct xattr_search_key search = X_SEARCH(type, name, strlen(name));
140	struct btree_iter iter;
141	struct bkey_s_c_xattr xattr;
142	struct bkey_s_c k;
143	int ret;
144
145	ret = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc, &hash,
146			       inode_inum(inode), &search, 0);
147	if (ret)
148		goto err1;
149
150	k = bch2_btree_iter_peek_slot(&iter);
151	ret = bkey_err(k);
152	if (ret)
153		goto err2;
154
155	xattr = bkey_s_c_to_xattr(k);
156	ret = le16_to_cpu(xattr.v->x_val_len);
157	if (buffer) {
158		if (ret > size)
159			ret = -ERANGE;
160		else
161			memcpy(buffer, xattr_val(xattr.v), ret);
162	}
163err2:
164	bch2_trans_iter_exit(trans, &iter);
165err1:
166	return ret < 0 && bch2_err_matches(ret, ENOENT) ? -ENODATA : ret;
167}
168
169int bch2_xattr_set(struct btree_trans *trans, subvol_inum inum,
170		   struct bch_inode_unpacked *inode_u,
171		   const struct bch_hash_info *hash_info,
172		   const char *name, const void *value, size_t size,
173		   int type, int flags)
174{
175	struct bch_fs *c = trans->c;
176	struct btree_iter inode_iter = { NULL };
177	int ret;
178
179	ret   = bch2_subvol_is_ro_trans(trans, inum.subvol) ?:
180		bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_INTENT);
181	if (ret)
182		return ret;
183
184	inode_u->bi_ctime = bch2_current_time(c);
185
186	ret = bch2_inode_write(trans, &inode_iter, inode_u);
187	bch2_trans_iter_exit(trans, &inode_iter);
188
189	if (ret)
190		return ret;
191
192	if (value) {
193		struct bkey_i_xattr *xattr;
194		unsigned namelen = strlen(name);
195		unsigned u64s = BKEY_U64s +
196			xattr_val_u64s(namelen, size);
197
198		if (u64s > U8_MAX)
199			return -ERANGE;
200
201		xattr = bch2_trans_kmalloc(trans, u64s * sizeof(u64));
202		if (IS_ERR(xattr))
203			return PTR_ERR(xattr);
204
205		bkey_xattr_init(&xattr->k_i);
206		xattr->k.u64s		= u64s;
207		xattr->v.x_type		= type;
208		xattr->v.x_name_len	= namelen;
209		xattr->v.x_val_len	= cpu_to_le16(size);
210		memcpy(xattr->v.x_name, name, namelen);
211		memcpy(xattr_val(&xattr->v), value, size);
212
213		ret = bch2_hash_set(trans, bch2_xattr_hash_desc, hash_info,
214			      inum, &xattr->k_i,
215			      (flags & XATTR_CREATE ? BCH_HASH_SET_MUST_CREATE : 0)|
216			      (flags & XATTR_REPLACE ? BCH_HASH_SET_MUST_REPLACE : 0));
217	} else {
218		struct xattr_search_key search =
219			X_SEARCH(type, name, strlen(name));
220
221		ret = bch2_hash_delete(trans, bch2_xattr_hash_desc,
222				       hash_info, inum, &search);
223	}
224
225	if (bch2_err_matches(ret, ENOENT))
226		ret = flags & XATTR_REPLACE ? -ENODATA : 0;
227
228	return ret;
229}
230
231struct xattr_buf {
232	char		*buf;
233	size_t		len;
234	size_t		used;
235};
236
237static int __bch2_xattr_emit(const char *prefix,
238			     const char *name, size_t name_len,
239			     struct xattr_buf *buf)
240{
241	const size_t prefix_len = strlen(prefix);
242	const size_t total_len = prefix_len + name_len + 1;
243
244	if (buf->buf) {
245		if (buf->used + total_len > buf->len)
246			return -ERANGE;
247
248		memcpy(buf->buf + buf->used, prefix, prefix_len);
249		memcpy(buf->buf + buf->used + prefix_len,
250		       name, name_len);
251		buf->buf[buf->used + prefix_len + name_len] = '\0';
252	}
253
254	buf->used += total_len;
255	return 0;
256}
257
258static int bch2_xattr_emit(struct dentry *dentry,
259			    const struct bch_xattr *xattr,
260			    struct xattr_buf *buf)
261{
262	const struct xattr_handler *handler =
263		bch2_xattr_type_to_handler(xattr->x_type);
264
265	return handler && (!handler->list || handler->list(dentry))
266		? __bch2_xattr_emit(handler->prefix ?: handler->name,
267				    xattr->x_name, xattr->x_name_len, buf)
268		: 0;
269}
270
271static int bch2_xattr_list_bcachefs(struct bch_fs *c,
272				    struct bch_inode_unpacked *inode,
273				    struct xattr_buf *buf,
274				    bool all)
275{
276	const char *prefix = all ? "bcachefs_effective." : "bcachefs.";
277	unsigned id;
278	int ret = 0;
279	u64 v;
280
281	for (id = 0; id < Inode_opt_nr; id++) {
282		v = bch2_inode_opt_get(inode, id);
283		if (!v)
284			continue;
285
286		if (!all &&
287		    !(inode->bi_fields_set & (1 << id)))
288			continue;
289
290		ret = __bch2_xattr_emit(prefix, bch2_inode_opts[id],
291					strlen(bch2_inode_opts[id]), buf);
292		if (ret)
293			break;
294	}
295
296	return ret;
297}
298
299ssize_t bch2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
300{
301	struct bch_fs *c = dentry->d_sb->s_fs_info;
302	struct bch_inode_info *inode = to_bch_ei(dentry->d_inode);
303	struct btree_trans *trans = bch2_trans_get(c);
304	struct btree_iter iter;
305	struct bkey_s_c k;
306	struct xattr_buf buf = { .buf = buffer, .len = buffer_size };
307	u64 offset = 0, inum = inode->ei_inode.bi_inum;
308	u32 snapshot;
309	int ret;
310retry:
311	bch2_trans_begin(trans);
312	iter = (struct btree_iter) { NULL };
313
314	ret = bch2_subvolume_get_snapshot(trans, inode->ei_subvol, &snapshot);
315	if (ret)
316		goto err;
317
318	for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_xattrs,
319			   SPOS(inum, offset, snapshot),
320			   POS(inum, U64_MAX), 0, k, ret) {
321		if (k.k->type != KEY_TYPE_xattr)
322			continue;
323
324		ret = bch2_xattr_emit(dentry, bkey_s_c_to_xattr(k).v, &buf);
325		if (ret)
326			break;
327	}
328
329	offset = iter.pos.offset;
330	bch2_trans_iter_exit(trans, &iter);
331err:
332	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
333		goto retry;
334
335	bch2_trans_put(trans);
336
337	if (ret)
338		goto out;
339
340	ret = bch2_xattr_list_bcachefs(c, &inode->ei_inode, &buf, false);
341	if (ret)
342		goto out;
343
344	ret = bch2_xattr_list_bcachefs(c, &inode->ei_inode, &buf, true);
345	if (ret)
346		goto out;
347
348	return buf.used;
349out:
350	return bch2_err_class(ret);
351}
352
353static int bch2_xattr_get_handler(const struct xattr_handler *handler,
354				  struct dentry *dentry, struct inode *vinode,
355				  const char *name, void *buffer, size_t size)
356{
357	struct bch_inode_info *inode = to_bch_ei(vinode);
358	struct bch_fs *c = inode->v.i_sb->s_fs_info;
359	int ret = bch2_trans_do(c, NULL, NULL, 0,
360		bch2_xattr_get_trans(trans, inode, name, buffer, size, handler->flags));
361
362	return bch2_err_class(ret);
363}
364
365static int bch2_xattr_set_handler(const struct xattr_handler *handler,
366				  struct mnt_idmap *idmap,
367				  struct dentry *dentry, struct inode *vinode,
368				  const char *name, const void *value,
369				  size_t size, int flags)
370{
371	struct bch_inode_info *inode = to_bch_ei(vinode);
372	struct bch_fs *c = inode->v.i_sb->s_fs_info;
373	struct bch_hash_info hash = bch2_hash_info_init(c, &inode->ei_inode);
374	struct bch_inode_unpacked inode_u;
375	int ret;
376
377	ret = bch2_trans_run(c,
378		commit_do(trans, NULL, NULL, 0,
379			bch2_xattr_set(trans, inode_inum(inode), &inode_u,
380				       &hash, name, value, size,
381				       handler->flags, flags)) ?:
382		(bch2_inode_update_after_write(trans, inode, &inode_u, ATTR_CTIME), 0));
383
384	return bch2_err_class(ret);
385}
386
387static const struct xattr_handler bch_xattr_user_handler = {
388	.prefix	= XATTR_USER_PREFIX,
389	.get	= bch2_xattr_get_handler,
390	.set	= bch2_xattr_set_handler,
391	.flags	= KEY_TYPE_XATTR_INDEX_USER,
392};
393
394static bool bch2_xattr_trusted_list(struct dentry *dentry)
395{
396	return capable(CAP_SYS_ADMIN);
397}
398
399static const struct xattr_handler bch_xattr_trusted_handler = {
400	.prefix	= XATTR_TRUSTED_PREFIX,
401	.list	= bch2_xattr_trusted_list,
402	.get	= bch2_xattr_get_handler,
403	.set	= bch2_xattr_set_handler,
404	.flags	= KEY_TYPE_XATTR_INDEX_TRUSTED,
405};
406
407static const struct xattr_handler bch_xattr_security_handler = {
408	.prefix	= XATTR_SECURITY_PREFIX,
409	.get	= bch2_xattr_get_handler,
410	.set	= bch2_xattr_set_handler,
411	.flags	= KEY_TYPE_XATTR_INDEX_SECURITY,
412};
413
414#ifndef NO_BCACHEFS_FS
415
416static int opt_to_inode_opt(int id)
417{
418	switch (id) {
419#define x(name, ...)				\
420	case Opt_##name: return Inode_opt_##name;
421	BCH_INODE_OPTS()
422#undef  x
423	default:
424		return -1;
425	}
426}
427
428static int __bch2_xattr_bcachefs_get(const struct xattr_handler *handler,
429				struct dentry *dentry, struct inode *vinode,
430				const char *name, void *buffer, size_t size,
431				bool all)
432{
433	struct bch_inode_info *inode = to_bch_ei(vinode);
434	struct bch_fs *c = inode->v.i_sb->s_fs_info;
435	struct bch_opts opts =
436		bch2_inode_opts_to_opts(&inode->ei_inode);
437	const struct bch_option *opt;
438	int id, inode_opt_id;
439	struct printbuf out = PRINTBUF;
440	int ret;
441	u64 v;
442
443	id = bch2_opt_lookup(name);
444	if (id < 0 || !bch2_opt_is_inode_opt(id))
445		return -EINVAL;
446
447	inode_opt_id = opt_to_inode_opt(id);
448	if (inode_opt_id < 0)
449		return -EINVAL;
450
451	opt = bch2_opt_table + id;
452
453	if (!bch2_opt_defined_by_id(&opts, id))
454		return -ENODATA;
455
456	if (!all &&
457	    !(inode->ei_inode.bi_fields_set & (1 << inode_opt_id)))
458		return -ENODATA;
459
460	v = bch2_opt_get_by_id(&opts, id);
461	bch2_opt_to_text(&out, c, c->disk_sb.sb, opt, v, 0);
462
463	ret = out.pos;
464
465	if (out.allocation_failure) {
466		ret = -ENOMEM;
467	} else if (buffer) {
468		if (out.pos > size)
469			ret = -ERANGE;
470		else
471			memcpy(buffer, out.buf, out.pos);
472	}
473
474	printbuf_exit(&out);
475	return ret;
476}
477
478static int bch2_xattr_bcachefs_get(const struct xattr_handler *handler,
479				   struct dentry *dentry, struct inode *vinode,
480				   const char *name, void *buffer, size_t size)
481{
482	return __bch2_xattr_bcachefs_get(handler, dentry, vinode,
483					 name, buffer, size, false);
484}
485
486struct inode_opt_set {
487	int			id;
488	u64			v;
489	bool			defined;
490};
491
492static int inode_opt_set_fn(struct btree_trans *trans,
493			    struct bch_inode_info *inode,
494			    struct bch_inode_unpacked *bi,
495			    void *p)
496{
497	struct inode_opt_set *s = p;
498
499	if (s->defined)
500		bi->bi_fields_set |= 1U << s->id;
501	else
502		bi->bi_fields_set &= ~(1U << s->id);
503
504	bch2_inode_opt_set(bi, s->id, s->v);
505
506	return 0;
507}
508
509static int bch2_xattr_bcachefs_set(const struct xattr_handler *handler,
510				   struct mnt_idmap *idmap,
511				   struct dentry *dentry, struct inode *vinode,
512				   const char *name, const void *value,
513				   size_t size, int flags)
514{
515	struct bch_inode_info *inode = to_bch_ei(vinode);
516	struct bch_fs *c = inode->v.i_sb->s_fs_info;
517	const struct bch_option *opt;
518	char *buf;
519	struct inode_opt_set s;
520	int opt_id, inode_opt_id, ret;
521
522	opt_id = bch2_opt_lookup(name);
523	if (opt_id < 0)
524		return -EINVAL;
525
526	opt = bch2_opt_table + opt_id;
527
528	inode_opt_id = opt_to_inode_opt(opt_id);
529	if (inode_opt_id < 0)
530		return -EINVAL;
531
532	s.id = inode_opt_id;
533
534	if (value) {
535		u64 v = 0;
536
537		buf = kmalloc(size + 1, GFP_KERNEL);
538		if (!buf)
539			return -ENOMEM;
540		memcpy(buf, value, size);
541		buf[size] = '\0';
542
543		ret = bch2_opt_parse(c, opt, buf, &v, NULL);
544		kfree(buf);
545
546		if (ret < 0)
547			goto err_class_exit;
548
549		ret = bch2_opt_check_may_set(c, opt_id, v);
550		if (ret < 0)
551			goto err_class_exit;
552
553		s.v = v + 1;
554		s.defined = true;
555	} else {
556		/*
557		 * Check if this option was set on the parent - if so, switched
558		 * back to inheriting from the parent:
559		 *
560		 * rename() also has to deal with keeping inherited options up
561		 * to date - see bch2_reinherit_attrs()
562		 */
563		spin_lock(&dentry->d_lock);
564		if (!IS_ROOT(dentry)) {
565			struct bch_inode_info *dir =
566				to_bch_ei(d_inode(dentry->d_parent));
567
568			s.v = bch2_inode_opt_get(&dir->ei_inode, inode_opt_id);
569		} else {
570			s.v = 0;
571		}
572		spin_unlock(&dentry->d_lock);
573
574		s.defined = false;
575	}
576
577	mutex_lock(&inode->ei_update_lock);
578	if (inode_opt_id == Inode_opt_project) {
579		/*
580		 * inode fields accessible via the xattr interface are stored
581		 * with a +1 bias, so that 0 means unset:
582		 */
583		ret = bch2_set_projid(c, inode, s.v ? s.v - 1 : 0);
584		if (ret)
585			goto err;
586	}
587
588	ret = bch2_write_inode(c, inode, inode_opt_set_fn, &s, 0);
589err:
590	mutex_unlock(&inode->ei_update_lock);
591
592	if (value &&
593	    (opt_id == Opt_background_target ||
594	     opt_id == Opt_background_compression ||
595	     (opt_id == Opt_compression && !inode_opt_get(c, &inode->ei_inode, background_compression))))
596		bch2_set_rebalance_needs_scan(c, inode->ei_inode.bi_inum);
597
598err_class_exit:
599	return bch2_err_class(ret);
600}
601
602static const struct xattr_handler bch_xattr_bcachefs_handler = {
603	.prefix	= "bcachefs.",
604	.get	= bch2_xattr_bcachefs_get,
605	.set	= bch2_xattr_bcachefs_set,
606};
607
608static int bch2_xattr_bcachefs_get_effective(
609				const struct xattr_handler *handler,
610				struct dentry *dentry, struct inode *vinode,
611				const char *name, void *buffer, size_t size)
612{
613	return __bch2_xattr_bcachefs_get(handler, dentry, vinode,
614					 name, buffer, size, true);
615}
616
617static const struct xattr_handler bch_xattr_bcachefs_effective_handler = {
618	.prefix	= "bcachefs_effective.",
619	.get	= bch2_xattr_bcachefs_get_effective,
620	.set	= bch2_xattr_bcachefs_set,
621};
622
623#endif /* NO_BCACHEFS_FS */
624
625const struct xattr_handler *bch2_xattr_handlers[] = {
626	&bch_xattr_user_handler,
627#ifdef CONFIG_BCACHEFS_POSIX_ACL
628	&nop_posix_acl_access,
629	&nop_posix_acl_default,
630#endif
631	&bch_xattr_trusted_handler,
632	&bch_xattr_security_handler,
633#ifndef NO_BCACHEFS_FS
634	&bch_xattr_bcachefs_handler,
635	&bch_xattr_bcachefs_effective_handler,
636#endif
637	NULL
638};
639
640static const struct xattr_handler *bch_xattr_handler_map[] = {
641	[KEY_TYPE_XATTR_INDEX_USER]			= &bch_xattr_user_handler,
642	[KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS]	=
643		&nop_posix_acl_access,
644	[KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT]	=
645		&nop_posix_acl_default,
646	[KEY_TYPE_XATTR_INDEX_TRUSTED]		= &bch_xattr_trusted_handler,
647	[KEY_TYPE_XATTR_INDEX_SECURITY]		= &bch_xattr_security_handler,
648};
649
650static const struct xattr_handler *bch2_xattr_type_to_handler(unsigned type)
651{
652	return type < ARRAY_SIZE(bch_xattr_handler_map)
653		? bch_xattr_handler_map[type]
654		: NULL;
655}
656