xref: /linux/fs/bcachefs/fs-ioctl.c (revision d642ef71) 
1 // SPDX-License-Identifier: GPL-2.0
2 #ifndef NO_BCACHEFS_FS
3 
4 #include "bcachefs.h"
5 #include "chardev.h"
6 #include "dirent.h"
7 #include "fs.h"
8 #include "fs-common.h"
9 #include "fs-ioctl.h"
10 #include "quota.h"
11 
12 #include <linux/compat.h>
13 #include <linux/fsnotify.h>
14 #include <linux/mount.h>
15 #include <linux/namei.h>
16 #include <linux/security.h>
17 #include <linux/writeback.h>
18 
19 #define FS_IOC_GOINGDOWN	     _IOR('X', 125, __u32)
20 #define FSOP_GOING_FLAGS_DEFAULT	0x0	/* going down */
21 #define FSOP_GOING_FLAGS_LOGFLUSH	0x1	/* flush log but not data */
22 #define FSOP_GOING_FLAGS_NOLOGFLUSH	0x2	/* don't flush log nor data */
23 
24 struct flags_set {
25 	unsigned		mask;
26 	unsigned		flags;
27 
28 	unsigned		projid;
29 
30 	bool			set_projinherit;
31 	bool			projinherit;
32 };
33 
34 static int bch2_inode_flags_set(struct btree_trans *trans,
35 				struct bch_inode_info *inode,
36 				struct bch_inode_unpacked *bi,
37 				void *p)
38 {
39 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
40 	/*
41 	 * We're relying on btree locking here for exclusion with other ioctl
42 	 * calls - use the flags in the btree (@bi), not inode->i_flags:
43 	 */
44 	struct flags_set *s = p;
45 	unsigned newflags = s->flags;
46 	unsigned oldflags = bi->bi_flags & s->mask;
47 
48 	if (((newflags ^ oldflags) & (BCH_INODE_append|BCH_INODE_immutable)) &&
49 	    !capable(CAP_LINUX_IMMUTABLE))
50 		return -EPERM;
51 
52 	if (!S_ISREG(bi->bi_mode) &&
53 	    !S_ISDIR(bi->bi_mode) &&
54 	    (newflags & (BCH_INODE_nodump|BCH_INODE_noatime)) != newflags)
55 		return -EINVAL;
56 
57 	if (s->set_projinherit) {
58 		bi->bi_fields_set &= ~(1 << Inode_opt_project);
59 		bi->bi_fields_set |= ((int) s->projinherit << Inode_opt_project);
60 	}
61 
62 	bi->bi_flags &= ~s->mask;
63 	bi->bi_flags |= newflags;
64 
65 	bi->bi_ctime = timespec_to_bch2_time(c, current_time(&inode->v));
66 	return 0;
67 }
68 
69 static int bch2_ioc_getflags(struct bch_inode_info *inode, int __user *arg)
70 {
71 	unsigned flags = map_flags(bch_flags_to_uflags, inode->ei_inode.bi_flags);
72 
73 	return put_user(flags, arg);
74 }
75 
76 static int bch2_ioc_setflags(struct bch_fs *c,
77 			     struct file *file,
78 			     struct bch_inode_info *inode,
79 			     void __user *arg)
80 {
81 	struct flags_set s = { .mask = map_defined(bch_flags_to_uflags) };
82 	unsigned uflags;
83 	int ret;
84 
85 	if (get_user(uflags, (int __user *) arg))
86 		return -EFAULT;
87 
88 	s.flags = map_flags_rev(bch_flags_to_uflags, uflags);
89 	if (uflags)
90 		return -EOPNOTSUPP;
91 
92 	ret = mnt_want_write_file(file);
93 	if (ret)
94 		return ret;
95 
96 	inode_lock(&inode->v);
97 	if (!inode_owner_or_capable(file_mnt_idmap(file), &inode->v)) {
98 		ret = -EACCES;
99 		goto setflags_out;
100 	}
101 
102 	mutex_lock(&inode->ei_update_lock);
103 	ret = bch2_write_inode(c, inode, bch2_inode_flags_set, &s,
104 			       ATTR_CTIME);
105 	mutex_unlock(&inode->ei_update_lock);
106 
107 setflags_out:
108 	inode_unlock(&inode->v);
109 	mnt_drop_write_file(file);
110 	return ret;
111 }
112 
113 static int bch2_ioc_fsgetxattr(struct bch_inode_info *inode,
114 			       struct fsxattr __user *arg)
115 {
116 	struct fsxattr fa = { 0 };
117 
118 	fa.fsx_xflags = map_flags(bch_flags_to_xflags, inode->ei_inode.bi_flags);
119 
120 	if (inode->ei_inode.bi_fields_set & (1 << Inode_opt_project))
121 		fa.fsx_xflags |= FS_XFLAG_PROJINHERIT;
122 
123 	fa.fsx_projid = inode->ei_qid.q[QTYP_PRJ];
124 
125 	if (copy_to_user(arg, &fa, sizeof(fa)))
126 		return -EFAULT;
127 
128 	return 0;
129 }
130 
131 static int fssetxattr_inode_update_fn(struct btree_trans *trans,
132 				      struct bch_inode_info *inode,
133 				      struct bch_inode_unpacked *bi,
134 				      void *p)
135 {
136 	struct flags_set *s = p;
137 
138 	if (s->projid != bi->bi_project) {
139 		bi->bi_fields_set |= 1U << Inode_opt_project;
140 		bi->bi_project = s->projid;
141 	}
142 
143 	return bch2_inode_flags_set(trans, inode, bi, p);
144 }
145 
146 static int bch2_ioc_fssetxattr(struct bch_fs *c,
147 			       struct file *file,
148 			       struct bch_inode_info *inode,
149 			       struct fsxattr __user *arg)
150 {
151 	struct flags_set s = { .mask = map_defined(bch_flags_to_xflags) };
152 	struct fsxattr fa;
153 	int ret;
154 
155 	if (copy_from_user(&fa, arg, sizeof(fa)))
156 		return -EFAULT;
157 
158 	s.set_projinherit = true;
159 	s.projinherit = (fa.fsx_xflags & FS_XFLAG_PROJINHERIT) != 0;
160 	fa.fsx_xflags &= ~FS_XFLAG_PROJINHERIT;
161 
162 	s.flags = map_flags_rev(bch_flags_to_xflags, fa.fsx_xflags);
163 	if (fa.fsx_xflags)
164 		return -EOPNOTSUPP;
165 
166 	if (fa.fsx_projid >= U32_MAX)
167 		return -EINVAL;
168 
169 	/*
170 	 * inode fields accessible via the xattr interface are stored with a +1
171 	 * bias, so that 0 means unset:
172 	 */
173 	s.projid = fa.fsx_projid + 1;
174 
175 	ret = mnt_want_write_file(file);
176 	if (ret)
177 		return ret;
178 
179 	inode_lock(&inode->v);
180 	if (!inode_owner_or_capable(file_mnt_idmap(file), &inode->v)) {
181 		ret = -EACCES;
182 		goto err;
183 	}
184 
185 	mutex_lock(&inode->ei_update_lock);
186 	ret = bch2_set_projid(c, inode, fa.fsx_projid);
187 	if (ret)
188 		goto err_unlock;
189 
190 	ret = bch2_write_inode(c, inode, fssetxattr_inode_update_fn, &s,
191 			       ATTR_CTIME);
192 err_unlock:
193 	mutex_unlock(&inode->ei_update_lock);
194 err:
195 	inode_unlock(&inode->v);
196 	mnt_drop_write_file(file);
197 	return ret;
198 }
199 
200 static int bch2_reinherit_attrs_fn(struct btree_trans *trans,
201 				   struct bch_inode_info *inode,
202 				   struct bch_inode_unpacked *bi,
203 				   void *p)
204 {
205 	struct bch_inode_info *dir = p;
206 
207 	return !bch2_reinherit_attrs(bi, &dir->ei_inode);
208 }
209 
210 static int bch2_ioc_reinherit_attrs(struct bch_fs *c,
211 				    struct file *file,
212 				    struct bch_inode_info *src,
213 				    const char __user *name)
214 {
215 	struct bch_hash_info hash = bch2_hash_info_init(c, &src->ei_inode);
216 	struct bch_inode_info *dst;
217 	struct inode *vinode = NULL;
218 	char *kname = NULL;
219 	struct qstr qstr;
220 	int ret = 0;
221 	subvol_inum inum;
222 
223 	kname = kmalloc(BCH_NAME_MAX + 1, GFP_KERNEL);
224 	if (!kname)
225 		return -ENOMEM;
226 
227 	ret = strncpy_from_user(kname, name, BCH_NAME_MAX);
228 	if (unlikely(ret < 0))
229 		goto err1;
230 
231 	qstr.len	= ret;
232 	qstr.name	= kname;
233 
234 	ret = bch2_dirent_lookup(c, inode_inum(src), &hash, &qstr, &inum);
235 	if (ret)
236 		goto err1;
237 
238 	vinode = bch2_vfs_inode_get(c, inum);
239 	ret = PTR_ERR_OR_ZERO(vinode);
240 	if (ret)
241 		goto err1;
242 
243 	dst = to_bch_ei(vinode);
244 
245 	ret = mnt_want_write_file(file);
246 	if (ret)
247 		goto err2;
248 
249 	bch2_lock_inodes(INODE_UPDATE_LOCK, src, dst);
250 
251 	if (inode_attr_changing(src, dst, Inode_opt_project)) {
252 		ret = bch2_fs_quota_transfer(c, dst,
253 					     src->ei_qid,
254 					     1 << QTYP_PRJ,
255 					     KEY_TYPE_QUOTA_PREALLOC);
256 		if (ret)
257 			goto err3;
258 	}
259 
260 	ret = bch2_write_inode(c, dst, bch2_reinherit_attrs_fn, src, 0);
261 err3:
262 	bch2_unlock_inodes(INODE_UPDATE_LOCK, src, dst);
263 
264 	/* return true if we did work */
265 	if (ret >= 0)
266 		ret = !ret;
267 
268 	mnt_drop_write_file(file);
269 err2:
270 	iput(vinode);
271 err1:
272 	kfree(kname);
273 
274 	return ret;
275 }
276 
277 static int bch2_ioc_goingdown(struct bch_fs *c, u32 __user *arg)
278 {
279 	u32 flags;
280 	int ret = 0;
281 
282 	if (!capable(CAP_SYS_ADMIN))
283 		return -EPERM;
284 
285 	if (get_user(flags, arg))
286 		return -EFAULT;
287 
288 	bch_notice(c, "shutdown by ioctl type %u", flags);
289 
290 	down_write(&c->vfs_sb->s_umount);
291 
292 	switch (flags) {
293 	case FSOP_GOING_FLAGS_DEFAULT:
294 		ret = freeze_bdev(c->vfs_sb->s_bdev);
295 		if (ret)
296 			goto err;
297 
298 		bch2_journal_flush(&c->journal);
299 		c->vfs_sb->s_flags |= SB_RDONLY;
300 		bch2_fs_emergency_read_only(c);
301 		thaw_bdev(c->vfs_sb->s_bdev);
302 		break;
303 
304 	case FSOP_GOING_FLAGS_LOGFLUSH:
305 		bch2_journal_flush(&c->journal);
306 		fallthrough;
307 
308 	case FSOP_GOING_FLAGS_NOLOGFLUSH:
309 		c->vfs_sb->s_flags |= SB_RDONLY;
310 		bch2_fs_emergency_read_only(c);
311 		break;
312 	default:
313 		ret = -EINVAL;
314 		break;
315 	}
316 err:
317 	up_write(&c->vfs_sb->s_umount);
318 	return ret;
319 }
320 
321 static long __bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
322 					  struct bch_ioctl_subvolume arg)
323 {
324 	struct inode *dir;
325 	struct bch_inode_info *inode;
326 	struct user_namespace *s_user_ns;
327 	struct dentry *dst_dentry;
328 	struct path src_path, dst_path;
329 	int how = LOOKUP_FOLLOW;
330 	int error;
331 	subvol_inum snapshot_src = { 0 };
332 	unsigned lookup_flags = 0;
333 	unsigned create_flags = BCH_CREATE_SUBVOL;
334 
335 	if (arg.flags & ~(BCH_SUBVOL_SNAPSHOT_CREATE|
336 			  BCH_SUBVOL_SNAPSHOT_RO))
337 		return -EINVAL;
338 
339 	if (!(arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
340 	    (arg.src_ptr ||
341 	     (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)))
342 		return -EINVAL;
343 
344 	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
345 		create_flags |= BCH_CREATE_SNAPSHOT;
346 
347 	if (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)
348 		create_flags |= BCH_CREATE_SNAPSHOT_RO;
349 
350 	/* why do we need this lock? */
351 	down_read(&c->vfs_sb->s_umount);
352 
353 	if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
354 		sync_inodes_sb(c->vfs_sb);
355 retry:
356 	if (arg.src_ptr) {
357 		error = user_path_at(arg.dirfd,
358 				(const char __user *)(unsigned long)arg.src_ptr,
359 				how, &src_path);
360 		if (error)
361 			goto err1;
362 
363 		if (src_path.dentry->d_sb->s_fs_info != c) {
364 			path_put(&src_path);
365 			error = -EXDEV;
366 			goto err1;
367 		}
368 
369 		snapshot_src = inode_inum(to_bch_ei(src_path.dentry->d_inode));
370 	}
371 
372 	dst_dentry = user_path_create(arg.dirfd,
373 			(const char __user *)(unsigned long)arg.dst_ptr,
374 			&dst_path, lookup_flags);
375 	error = PTR_ERR_OR_ZERO(dst_dentry);
376 	if (error)
377 		goto err2;
378 
379 	if (dst_dentry->d_sb->s_fs_info != c) {
380 		error = -EXDEV;
381 		goto err3;
382 	}
383 
384 	if (dst_dentry->d_inode) {
385 		error = -EEXIST;
386 		goto err3;
387 	}
388 
389 	dir = dst_path.dentry->d_inode;
390 	if (IS_DEADDIR(dir)) {
391 		error = -BCH_ERR_ENOENT_directory_dead;
392 		goto err3;
393 	}
394 
395 	s_user_ns = dir->i_sb->s_user_ns;
396 	if (!kuid_has_mapping(s_user_ns, current_fsuid()) ||
397 	    !kgid_has_mapping(s_user_ns, current_fsgid())) {
398 		error = -EOVERFLOW;
399 		goto err3;
400 	}
401 
402 	error = inode_permission(file_mnt_idmap(filp),
403 				 dir, MAY_WRITE | MAY_EXEC);
404 	if (error)
405 		goto err3;
406 
407 	if (!IS_POSIXACL(dir))
408 		arg.mode &= ~current_umask();
409 
410 	error = security_path_mkdir(&dst_path, dst_dentry, arg.mode);
411 	if (error)
412 		goto err3;
413 
414 	if ((arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
415 	    !arg.src_ptr)
416 		snapshot_src.subvol = to_bch_ei(dir)->ei_inode.bi_subvol;
417 
418 	inode = __bch2_create(file_mnt_idmap(filp), to_bch_ei(dir),
419 			      dst_dentry, arg.mode|S_IFDIR,
420 			      0, snapshot_src, create_flags);
421 	error = PTR_ERR_OR_ZERO(inode);
422 	if (error)
423 		goto err3;
424 
425 	d_instantiate(dst_dentry, &inode->v);
426 	fsnotify_mkdir(dir, dst_dentry);
427 err3:
428 	done_path_create(&dst_path, dst_dentry);
429 err2:
430 	if (arg.src_ptr)
431 		path_put(&src_path);
432 
433 	if (retry_estale(error, lookup_flags)) {
434 		lookup_flags |= LOOKUP_REVAL;
435 		goto retry;
436 	}
437 err1:
438 	up_read(&c->vfs_sb->s_umount);
439 
440 	return error;
441 }
442 
443 static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
444 					struct bch_ioctl_subvolume arg)
445 {
446 	down_write(&c->snapshot_create_lock);
447 	long ret = __bch2_ioctl_subvolume_create(c, filp, arg);
448 	up_write(&c->snapshot_create_lock);
449 
450 	return ret;
451 }
452 
453 static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
454 				struct bch_ioctl_subvolume arg)
455 {
456 	struct path path;
457 	struct inode *dir;
458 	int ret = 0;
459 
460 	if (arg.flags)
461 		return -EINVAL;
462 
463 	ret = user_path_at(arg.dirfd,
464 			(const char __user *)(unsigned long)arg.dst_ptr,
465 			LOOKUP_FOLLOW, &path);
466 	if (ret)
467 		return ret;
468 
469 	if (path.dentry->d_sb->s_fs_info != c) {
470 		ret = -EXDEV;
471 		goto err;
472 	}
473 
474 	dir = path.dentry->d_parent->d_inode;
475 
476 	ret = __bch2_unlink(dir, path.dentry, true);
477 	if (ret)
478 		goto err;
479 
480 	fsnotify_rmdir(dir, path.dentry);
481 	d_delete(path.dentry);
482 err:
483 	path_put(&path);
484 	return ret;
485 }
486 
487 long bch2_fs_file_ioctl(struct file *file, unsigned cmd, unsigned long arg)
488 {
489 	struct bch_inode_info *inode = file_bch_inode(file);
490 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
491 	long ret;
492 
493 	switch (cmd) {
494 	case FS_IOC_GETFLAGS:
495 		ret = bch2_ioc_getflags(inode, (int __user *) arg);
496 		break;
497 
498 	case FS_IOC_SETFLAGS:
499 		ret = bch2_ioc_setflags(c, file, inode, (int __user *) arg);
500 		break;
501 
502 	case FS_IOC_FSGETXATTR:
503 		ret = bch2_ioc_fsgetxattr(inode, (void __user *) arg);
504 		break;
505 
506 	case FS_IOC_FSSETXATTR:
507 		ret = bch2_ioc_fssetxattr(c, file, inode,
508 					  (void __user *) arg);
509 		break;
510 
511 	case BCHFS_IOC_REINHERIT_ATTRS:
512 		ret = bch2_ioc_reinherit_attrs(c, file, inode,
513 					       (void __user *) arg);
514 		break;
515 
516 	case FS_IOC_GETVERSION:
517 		ret = -ENOTTY;
518 		break;
519 
520 	case FS_IOC_SETVERSION:
521 		ret = -ENOTTY;
522 		break;
523 
524 	case FS_IOC_GOINGDOWN:
525 		ret = bch2_ioc_goingdown(c, (u32 __user *) arg);
526 		break;
527 
528 	case BCH_IOCTL_SUBVOLUME_CREATE: {
529 		struct bch_ioctl_subvolume i;
530 
531 		ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
532 			? -EFAULT
533 			: bch2_ioctl_subvolume_create(c, file, i);
534 		break;
535 	}
536 
537 	case BCH_IOCTL_SUBVOLUME_DESTROY: {
538 		struct bch_ioctl_subvolume i;
539 
540 		ret = copy_from_user(&i, (void __user *) arg, sizeof(i))
541 			? -EFAULT
542 			: bch2_ioctl_subvolume_destroy(c, file, i);
543 		break;
544 	}
545 
546 	default:
547 		ret = bch2_fs_ioctl(c, cmd, (void __user *) arg);
548 		break;
549 	}
550 
551 	return bch2_err_class(ret);
552 }
553 
554 #ifdef CONFIG_COMPAT
555 long bch2_compat_fs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
556 {
557 	/* These are just misnamed, they actually get/put from/to user an int */
558 	switch (cmd) {
559 	case FS_IOC_GETFLAGS:
560 		cmd = FS_IOC_GETFLAGS;
561 		break;
562 	case FS_IOC32_SETFLAGS:
563 		cmd = FS_IOC_SETFLAGS;
564 		break;
565 	default:
566 		return -ENOIOCTLCMD;
567 	}
568 	return bch2_fs_file_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
569 }
570 #endif
571 
572 #endif /* NO_BCACHEFS_FS */
573