xref: /openbmc/linux/fs/nilfs2/ioctl.c (revision e4c0d0e2)
1 /*
2  * ioctl.c - NILFS ioctl operations.
3  *
4  * Copyright (C) 2007, 2008 Nippon Telegraph and Telephone Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  *
20  * Written by Koji Sato <koji@osrg.net>.
21  */
22 
23 #include <linux/fs.h>
24 #include <linux/wait.h>
25 #include <linux/slab.h>
26 #include <linux/capability.h>	/* capable() */
27 #include <linux/uaccess.h>	/* copy_from_user(), copy_to_user() */
28 #include <linux/vmalloc.h>
29 #include <linux/compat.h>	/* compat_ptr() */
30 #include <linux/mount.h>	/* mnt_want_write(), mnt_drop_write() */
31 #include <linux/buffer_head.h>
32 #include <linux/nilfs2_fs.h>
33 #include "nilfs.h"
34 #include "segment.h"
35 #include "bmap.h"
36 #include "cpfile.h"
37 #include "sufile.h"
38 #include "dat.h"
39 
40 
41 static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
42 				 struct nilfs_argv *argv, int dir,
43 				 ssize_t (*dofunc)(struct the_nilfs *,
44 						   __u64 *, int,
45 						   void *, size_t, size_t))
46 {
47 	void *buf;
48 	void __user *base = (void __user *)(unsigned long)argv->v_base;
49 	size_t maxmembs, total, n;
50 	ssize_t nr;
51 	int ret, i;
52 	__u64 pos, ppos;
53 
54 	if (argv->v_nmembs == 0)
55 		return 0;
56 
57 	if (argv->v_size > PAGE_SIZE)
58 		return -EINVAL;
59 
60 	buf = (void *)__get_free_pages(GFP_NOFS, 0);
61 	if (unlikely(!buf))
62 		return -ENOMEM;
63 	maxmembs = PAGE_SIZE / argv->v_size;
64 
65 	ret = 0;
66 	total = 0;
67 	pos = argv->v_index;
68 	for (i = 0; i < argv->v_nmembs; i += n) {
69 		n = (argv->v_nmembs - i < maxmembs) ?
70 			argv->v_nmembs - i : maxmembs;
71 		if ((dir & _IOC_WRITE) &&
72 		    copy_from_user(buf, base + argv->v_size * i,
73 				   argv->v_size * n)) {
74 			ret = -EFAULT;
75 			break;
76 		}
77 		ppos = pos;
78 		nr = dofunc(nilfs, &pos, argv->v_flags, buf, argv->v_size,
79 			       n);
80 		if (nr < 0) {
81 			ret = nr;
82 			break;
83 		}
84 		if ((dir & _IOC_READ) &&
85 		    copy_to_user(base + argv->v_size * i, buf,
86 				 argv->v_size * nr)) {
87 			ret = -EFAULT;
88 			break;
89 		}
90 		total += nr;
91 		if ((size_t)nr < n)
92 			break;
93 		if (pos == ppos)
94 			pos += n;
95 	}
96 	argv->v_nmembs = total;
97 
98 	free_pages((unsigned long)buf, 0);
99 	return ret;
100 }
101 
102 static int nilfs_ioctl_getflags(struct inode *inode, void __user *argp)
103 {
104 	unsigned int flags = NILFS_I(inode)->i_flags & FS_FL_USER_VISIBLE;
105 
106 	return put_user(flags, (int __user *)argp);
107 }
108 
109 static int nilfs_ioctl_setflags(struct inode *inode, struct file *filp,
110 				void __user *argp)
111 {
112 	struct nilfs_transaction_info ti;
113 	unsigned int flags, oldflags;
114 	int ret;
115 
116 	if (!inode_owner_or_capable(inode))
117 		return -EACCES;
118 
119 	if (get_user(flags, (int __user *)argp))
120 		return -EFAULT;
121 
122 	ret = mnt_want_write(filp->f_path.mnt);
123 	if (ret)
124 		return ret;
125 
126 	flags = nilfs_mask_flags(inode->i_mode, flags);
127 
128 	mutex_lock(&inode->i_mutex);
129 
130 	oldflags = NILFS_I(inode)->i_flags;
131 
132 	/*
133 	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by the
134 	 * relevant capability.
135 	 */
136 	ret = -EPERM;
137 	if (((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) &&
138 	    !capable(CAP_LINUX_IMMUTABLE))
139 		goto out;
140 
141 	ret = nilfs_transaction_begin(inode->i_sb, &ti, 0);
142 	if (ret)
143 		goto out;
144 
145 	NILFS_I(inode)->i_flags = (oldflags & ~FS_FL_USER_MODIFIABLE) |
146 		(flags & FS_FL_USER_MODIFIABLE);
147 
148 	nilfs_set_inode_flags(inode);
149 	inode->i_ctime = CURRENT_TIME;
150 	if (IS_SYNC(inode))
151 		nilfs_set_transaction_flag(NILFS_TI_SYNC);
152 
153 	nilfs_mark_inode_dirty(inode);
154 	ret = nilfs_transaction_commit(inode->i_sb);
155 out:
156 	mutex_unlock(&inode->i_mutex);
157 	mnt_drop_write(filp->f_path.mnt);
158 	return ret;
159 }
160 
161 static int nilfs_ioctl_getversion(struct inode *inode, void __user *argp)
162 {
163 	return put_user(inode->i_generation, (int __user *)argp);
164 }
165 
166 static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
167 				     unsigned int cmd, void __user *argp)
168 {
169 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
170 	struct nilfs_transaction_info ti;
171 	struct nilfs_cpmode cpmode;
172 	int ret;
173 
174 	if (!capable(CAP_SYS_ADMIN))
175 		return -EPERM;
176 
177 	ret = mnt_want_write(filp->f_path.mnt);
178 	if (ret)
179 		return ret;
180 
181 	ret = -EFAULT;
182 	if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
183 		goto out;
184 
185 	down_read(&inode->i_sb->s_umount);
186 
187 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
188 	ret = nilfs_cpfile_change_cpmode(
189 		nilfs->ns_cpfile, cpmode.cm_cno, cpmode.cm_mode);
190 	if (unlikely(ret < 0))
191 		nilfs_transaction_abort(inode->i_sb);
192 	else
193 		nilfs_transaction_commit(inode->i_sb); /* never fails */
194 
195 	up_read(&inode->i_sb->s_umount);
196 out:
197 	mnt_drop_write(filp->f_path.mnt);
198 	return ret;
199 }
200 
201 static int
202 nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
203 			      unsigned int cmd, void __user *argp)
204 {
205 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
206 	struct nilfs_transaction_info ti;
207 	__u64 cno;
208 	int ret;
209 
210 	if (!capable(CAP_SYS_ADMIN))
211 		return -EPERM;
212 
213 	ret = mnt_want_write(filp->f_path.mnt);
214 	if (ret)
215 		return ret;
216 
217 	ret = -EFAULT;
218 	if (copy_from_user(&cno, argp, sizeof(cno)))
219 		goto out;
220 
221 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
222 	ret = nilfs_cpfile_delete_checkpoint(nilfs->ns_cpfile, cno);
223 	if (unlikely(ret < 0))
224 		nilfs_transaction_abort(inode->i_sb);
225 	else
226 		nilfs_transaction_commit(inode->i_sb); /* never fails */
227 out:
228 	mnt_drop_write(filp->f_path.mnt);
229 	return ret;
230 }
231 
232 static ssize_t
233 nilfs_ioctl_do_get_cpinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
234 			  void *buf, size_t size, size_t nmembs)
235 {
236 	int ret;
237 
238 	down_read(&nilfs->ns_segctor_sem);
239 	ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
240 				      size, nmembs);
241 	up_read(&nilfs->ns_segctor_sem);
242 	return ret;
243 }
244 
245 static int nilfs_ioctl_get_cpstat(struct inode *inode, struct file *filp,
246 				  unsigned int cmd, void __user *argp)
247 {
248 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
249 	struct nilfs_cpstat cpstat;
250 	int ret;
251 
252 	down_read(&nilfs->ns_segctor_sem);
253 	ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
254 	up_read(&nilfs->ns_segctor_sem);
255 	if (ret < 0)
256 		return ret;
257 
258 	if (copy_to_user(argp, &cpstat, sizeof(cpstat)))
259 		ret = -EFAULT;
260 	return ret;
261 }
262 
263 static ssize_t
264 nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
265 			  void *buf, size_t size, size_t nmembs)
266 {
267 	int ret;
268 
269 	down_read(&nilfs->ns_segctor_sem);
270 	ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
271 				      nmembs);
272 	up_read(&nilfs->ns_segctor_sem);
273 	return ret;
274 }
275 
276 static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
277 				  unsigned int cmd, void __user *argp)
278 {
279 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
280 	struct nilfs_sustat sustat;
281 	int ret;
282 
283 	down_read(&nilfs->ns_segctor_sem);
284 	ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
285 	up_read(&nilfs->ns_segctor_sem);
286 	if (ret < 0)
287 		return ret;
288 
289 	if (copy_to_user(argp, &sustat, sizeof(sustat)))
290 		ret = -EFAULT;
291 	return ret;
292 }
293 
294 static ssize_t
295 nilfs_ioctl_do_get_vinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
296 			 void *buf, size_t size, size_t nmembs)
297 {
298 	int ret;
299 
300 	down_read(&nilfs->ns_segctor_sem);
301 	ret = nilfs_dat_get_vinfo(nilfs->ns_dat, buf, size, nmembs);
302 	up_read(&nilfs->ns_segctor_sem);
303 	return ret;
304 }
305 
306 static ssize_t
307 nilfs_ioctl_do_get_bdescs(struct the_nilfs *nilfs, __u64 *posp, int flags,
308 			  void *buf, size_t size, size_t nmembs)
309 {
310 	struct nilfs_bmap *bmap = NILFS_I(nilfs->ns_dat)->i_bmap;
311 	struct nilfs_bdesc *bdescs = buf;
312 	int ret, i;
313 
314 	down_read(&nilfs->ns_segctor_sem);
315 	for (i = 0; i < nmembs; i++) {
316 		ret = nilfs_bmap_lookup_at_level(bmap,
317 						 bdescs[i].bd_offset,
318 						 bdescs[i].bd_level + 1,
319 						 &bdescs[i].bd_blocknr);
320 		if (ret < 0) {
321 			if (ret != -ENOENT) {
322 				up_read(&nilfs->ns_segctor_sem);
323 				return ret;
324 			}
325 			bdescs[i].bd_blocknr = 0;
326 		}
327 	}
328 	up_read(&nilfs->ns_segctor_sem);
329 	return nmembs;
330 }
331 
332 static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp,
333 				  unsigned int cmd, void __user *argp)
334 {
335 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
336 	struct nilfs_argv argv;
337 	int ret;
338 
339 	if (copy_from_user(&argv, argp, sizeof(argv)))
340 		return -EFAULT;
341 
342 	if (argv.v_size != sizeof(struct nilfs_bdesc))
343 		return -EINVAL;
344 
345 	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
346 				    nilfs_ioctl_do_get_bdescs);
347 	if (ret < 0)
348 		return ret;
349 
350 	if (copy_to_user(argp, &argv, sizeof(argv)))
351 		ret = -EFAULT;
352 	return ret;
353 }
354 
355 static int nilfs_ioctl_move_inode_block(struct inode *inode,
356 					struct nilfs_vdesc *vdesc,
357 					struct list_head *buffers)
358 {
359 	struct buffer_head *bh;
360 	int ret;
361 
362 	if (vdesc->vd_flags == 0)
363 		ret = nilfs_gccache_submit_read_data(
364 			inode, vdesc->vd_offset, vdesc->vd_blocknr,
365 			vdesc->vd_vblocknr, &bh);
366 	else
367 		ret = nilfs_gccache_submit_read_node(
368 			inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh);
369 
370 	if (unlikely(ret < 0)) {
371 		if (ret == -ENOENT)
372 			printk(KERN_CRIT
373 			       "%s: invalid virtual block address (%s): "
374 			       "ino=%llu, cno=%llu, offset=%llu, "
375 			       "blocknr=%llu, vblocknr=%llu\n",
376 			       __func__, vdesc->vd_flags ? "node" : "data",
377 			       (unsigned long long)vdesc->vd_ino,
378 			       (unsigned long long)vdesc->vd_cno,
379 			       (unsigned long long)vdesc->vd_offset,
380 			       (unsigned long long)vdesc->vd_blocknr,
381 			       (unsigned long long)vdesc->vd_vblocknr);
382 		return ret;
383 	}
384 	if (unlikely(!list_empty(&bh->b_assoc_buffers))) {
385 		printk(KERN_CRIT "%s: conflicting %s buffer: ino=%llu, "
386 		       "cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu\n",
387 		       __func__, vdesc->vd_flags ? "node" : "data",
388 		       (unsigned long long)vdesc->vd_ino,
389 		       (unsigned long long)vdesc->vd_cno,
390 		       (unsigned long long)vdesc->vd_offset,
391 		       (unsigned long long)vdesc->vd_blocknr,
392 		       (unsigned long long)vdesc->vd_vblocknr);
393 		brelse(bh);
394 		return -EEXIST;
395 	}
396 	list_add_tail(&bh->b_assoc_buffers, buffers);
397 	return 0;
398 }
399 
400 static int nilfs_ioctl_move_blocks(struct super_block *sb,
401 				   struct nilfs_argv *argv, void *buf)
402 {
403 	size_t nmembs = argv->v_nmembs;
404 	struct the_nilfs *nilfs = sb->s_fs_info;
405 	struct inode *inode;
406 	struct nilfs_vdesc *vdesc;
407 	struct buffer_head *bh, *n;
408 	LIST_HEAD(buffers);
409 	ino_t ino;
410 	__u64 cno;
411 	int i, ret;
412 
413 	for (i = 0, vdesc = buf; i < nmembs; ) {
414 		ino = vdesc->vd_ino;
415 		cno = vdesc->vd_cno;
416 		inode = nilfs_iget_for_gc(sb, ino, cno);
417 		if (IS_ERR(inode)) {
418 			ret = PTR_ERR(inode);
419 			goto failed;
420 		}
421 		if (list_empty(&NILFS_I(inode)->i_dirty)) {
422 			/*
423 			 * Add the inode to GC inode list. Garbage Collection
424 			 * is serialized and no two processes manipulate the
425 			 * list simultaneously.
426 			 */
427 			igrab(inode);
428 			list_add(&NILFS_I(inode)->i_dirty,
429 				 &nilfs->ns_gc_inodes);
430 		}
431 
432 		do {
433 			ret = nilfs_ioctl_move_inode_block(inode, vdesc,
434 							   &buffers);
435 			if (unlikely(ret < 0)) {
436 				iput(inode);
437 				goto failed;
438 			}
439 			vdesc++;
440 		} while (++i < nmembs &&
441 			 vdesc->vd_ino == ino && vdesc->vd_cno == cno);
442 
443 		iput(inode); /* The inode still remains in GC inode list */
444 	}
445 
446 	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
447 		ret = nilfs_gccache_wait_and_mark_dirty(bh);
448 		if (unlikely(ret < 0)) {
449 			WARN_ON(ret == -EEXIST);
450 			goto failed;
451 		}
452 		list_del_init(&bh->b_assoc_buffers);
453 		brelse(bh);
454 	}
455 	return nmembs;
456 
457  failed:
458 	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
459 		list_del_init(&bh->b_assoc_buffers);
460 		brelse(bh);
461 	}
462 	return ret;
463 }
464 
465 static int nilfs_ioctl_delete_checkpoints(struct the_nilfs *nilfs,
466 					  struct nilfs_argv *argv, void *buf)
467 {
468 	size_t nmembs = argv->v_nmembs;
469 	struct inode *cpfile = nilfs->ns_cpfile;
470 	struct nilfs_period *periods = buf;
471 	int ret, i;
472 
473 	for (i = 0; i < nmembs; i++) {
474 		ret = nilfs_cpfile_delete_checkpoints(
475 			cpfile, periods[i].p_start, periods[i].p_end);
476 		if (ret < 0)
477 			return ret;
478 	}
479 	return nmembs;
480 }
481 
482 static int nilfs_ioctl_free_vblocknrs(struct the_nilfs *nilfs,
483 				      struct nilfs_argv *argv, void *buf)
484 {
485 	size_t nmembs = argv->v_nmembs;
486 	int ret;
487 
488 	ret = nilfs_dat_freev(nilfs->ns_dat, buf, nmembs);
489 
490 	return (ret < 0) ? ret : nmembs;
491 }
492 
493 static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs,
494 					 struct nilfs_argv *argv, void *buf)
495 {
496 	size_t nmembs = argv->v_nmembs;
497 	struct nilfs_bmap *bmap = NILFS_I(nilfs->ns_dat)->i_bmap;
498 	struct nilfs_bdesc *bdescs = buf;
499 	int ret, i;
500 
501 	for (i = 0; i < nmembs; i++) {
502 		/* XXX: use macro or inline func to check liveness */
503 		ret = nilfs_bmap_lookup_at_level(bmap,
504 						 bdescs[i].bd_offset,
505 						 bdescs[i].bd_level + 1,
506 						 &bdescs[i].bd_blocknr);
507 		if (ret < 0) {
508 			if (ret != -ENOENT)
509 				return ret;
510 			bdescs[i].bd_blocknr = 0;
511 		}
512 		if (bdescs[i].bd_blocknr != bdescs[i].bd_oblocknr)
513 			/* skip dead block */
514 			continue;
515 		if (bdescs[i].bd_level == 0) {
516 			ret = nilfs_mdt_mark_block_dirty(nilfs->ns_dat,
517 							 bdescs[i].bd_offset);
518 			if (ret < 0) {
519 				WARN_ON(ret == -ENOENT);
520 				return ret;
521 			}
522 		} else {
523 			ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
524 					      bdescs[i].bd_level);
525 			if (ret < 0) {
526 				WARN_ON(ret == -ENOENT);
527 				return ret;
528 			}
529 		}
530 	}
531 	return nmembs;
532 }
533 
534 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
535 				       struct nilfs_argv *argv, void **kbufs)
536 {
537 	const char *msg;
538 	int ret;
539 
540 	ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
541 	if (ret < 0) {
542 		/*
543 		 * can safely abort because checkpoints can be removed
544 		 * independently.
545 		 */
546 		msg = "cannot delete checkpoints";
547 		goto failed;
548 	}
549 	ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], kbufs[2]);
550 	if (ret < 0) {
551 		/*
552 		 * can safely abort because DAT file is updated atomically
553 		 * using a copy-on-write technique.
554 		 */
555 		msg = "cannot delete virtual blocks from DAT file";
556 		goto failed;
557 	}
558 	ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], kbufs[3]);
559 	if (ret < 0) {
560 		/*
561 		 * can safely abort because the operation is nondestructive.
562 		 */
563 		msg = "cannot mark copying blocks dirty";
564 		goto failed;
565 	}
566 	return 0;
567 
568  failed:
569 	printk(KERN_ERR "NILFS: GC failed during preparation: %s: err=%d\n",
570 	       msg, ret);
571 	return ret;
572 }
573 
574 static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
575 				      unsigned int cmd, void __user *argp)
576 {
577 	struct nilfs_argv argv[5];
578 	static const size_t argsz[5] = {
579 		sizeof(struct nilfs_vdesc),
580 		sizeof(struct nilfs_period),
581 		sizeof(__u64),
582 		sizeof(struct nilfs_bdesc),
583 		sizeof(__u64),
584 	};
585 	void __user *base;
586 	void *kbufs[5];
587 	struct the_nilfs *nilfs;
588 	size_t len, nsegs;
589 	int n, ret;
590 
591 	if (!capable(CAP_SYS_ADMIN))
592 		return -EPERM;
593 
594 	ret = mnt_want_write(filp->f_path.mnt);
595 	if (ret)
596 		return ret;
597 
598 	ret = -EFAULT;
599 	if (copy_from_user(argv, argp, sizeof(argv)))
600 		goto out;
601 
602 	ret = -EINVAL;
603 	nsegs = argv[4].v_nmembs;
604 	if (argv[4].v_size != argsz[4])
605 		goto out;
606 
607 	/*
608 	 * argv[4] points to segment numbers this ioctl cleans.  We
609 	 * use kmalloc() for its buffer because memory used for the
610 	 * segment numbers is enough small.
611 	 */
612 	kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
613 			       nsegs * sizeof(__u64));
614 	if (IS_ERR(kbufs[4])) {
615 		ret = PTR_ERR(kbufs[4]);
616 		goto out;
617 	}
618 	nilfs = inode->i_sb->s_fs_info;
619 
620 	for (n = 0; n < 4; n++) {
621 		ret = -EINVAL;
622 		if (argv[n].v_size != argsz[n])
623 			goto out_free;
624 
625 		if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
626 			goto out_free;
627 
628 		len = argv[n].v_size * argv[n].v_nmembs;
629 		base = (void __user *)(unsigned long)argv[n].v_base;
630 		if (len == 0) {
631 			kbufs[n] = NULL;
632 			continue;
633 		}
634 
635 		kbufs[n] = vmalloc(len);
636 		if (!kbufs[n]) {
637 			ret = -ENOMEM;
638 			goto out_free;
639 		}
640 		if (copy_from_user(kbufs[n], base, len)) {
641 			ret = -EFAULT;
642 			vfree(kbufs[n]);
643 			goto out_free;
644 		}
645 	}
646 
647 	/*
648 	 * nilfs_ioctl_move_blocks() will call nilfs_iget_for_gc(),
649 	 * which will operates an inode list without blocking.
650 	 * To protect the list from concurrent operations,
651 	 * nilfs_ioctl_move_blocks should be atomic operation.
652 	 */
653 	if (test_and_set_bit(THE_NILFS_GC_RUNNING, &nilfs->ns_flags)) {
654 		ret = -EBUSY;
655 		goto out_free;
656 	}
657 
658 	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
659 
660 	ret = nilfs_ioctl_move_blocks(inode->i_sb, &argv[0], kbufs[0]);
661 	if (ret < 0)
662 		printk(KERN_ERR "NILFS: GC failed during preparation: "
663 			"cannot read source blocks: err=%d\n", ret);
664 	else
665 		ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
666 
667 	nilfs_remove_all_gcinodes(nilfs);
668 	clear_nilfs_gc_running(nilfs);
669 
670 out_free:
671 	while (--n >= 0)
672 		vfree(kbufs[n]);
673 	kfree(kbufs[4]);
674 out:
675 	mnt_drop_write(filp->f_path.mnt);
676 	return ret;
677 }
678 
679 static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
680 			    unsigned int cmd, void __user *argp)
681 {
682 	__u64 cno;
683 	int ret;
684 	struct the_nilfs *nilfs;
685 
686 	ret = nilfs_construct_segment(inode->i_sb);
687 	if (ret < 0)
688 		return ret;
689 
690 	if (argp != NULL) {
691 		nilfs = inode->i_sb->s_fs_info;
692 		down_read(&nilfs->ns_segctor_sem);
693 		cno = nilfs->ns_cno - 1;
694 		up_read(&nilfs->ns_segctor_sem);
695 		if (copy_to_user(argp, &cno, sizeof(cno)))
696 			return -EFAULT;
697 	}
698 	return 0;
699 }
700 
701 static int nilfs_ioctl_resize(struct inode *inode, struct file *filp,
702 			      void __user *argp)
703 {
704 	__u64 newsize;
705 	int ret = -EPERM;
706 
707 	if (!capable(CAP_SYS_ADMIN))
708 		goto out;
709 
710 	ret = mnt_want_write(filp->f_path.mnt);
711 	if (ret)
712 		goto out;
713 
714 	ret = -EFAULT;
715 	if (copy_from_user(&newsize, argp, sizeof(newsize)))
716 		goto out_drop_write;
717 
718 	ret = nilfs_resize_fs(inode->i_sb, newsize);
719 
720 out_drop_write:
721 	mnt_drop_write(filp->f_path.mnt);
722 out:
723 	return ret;
724 }
725 
726 static int nilfs_ioctl_set_alloc_range(struct inode *inode, void __user *argp)
727 {
728 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
729 	__u64 range[2];
730 	__u64 minseg, maxseg;
731 	unsigned long segbytes;
732 	int ret = -EPERM;
733 
734 	if (!capable(CAP_SYS_ADMIN))
735 		goto out;
736 
737 	ret = -EFAULT;
738 	if (copy_from_user(range, argp, sizeof(__u64[2])))
739 		goto out;
740 
741 	ret = -ERANGE;
742 	if (range[1] > i_size_read(inode->i_sb->s_bdev->bd_inode))
743 		goto out;
744 
745 	segbytes = nilfs->ns_blocks_per_segment * nilfs->ns_blocksize;
746 
747 	minseg = range[0] + segbytes - 1;
748 	do_div(minseg, segbytes);
749 	maxseg = NILFS_SB2_OFFSET_BYTES(range[1]);
750 	do_div(maxseg, segbytes);
751 	maxseg--;
752 
753 	ret = nilfs_sufile_set_alloc_range(nilfs->ns_sufile, minseg, maxseg);
754 out:
755 	return ret;
756 }
757 
758 static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
759 				unsigned int cmd, void __user *argp,
760 				size_t membsz,
761 				ssize_t (*dofunc)(struct the_nilfs *,
762 						  __u64 *, int,
763 						  void *, size_t, size_t))
764 
765 {
766 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
767 	struct nilfs_argv argv;
768 	int ret;
769 
770 	if (copy_from_user(&argv, argp, sizeof(argv)))
771 		return -EFAULT;
772 
773 	if (argv.v_size < membsz)
774 		return -EINVAL;
775 
776 	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
777 	if (ret < 0)
778 		return ret;
779 
780 	if (copy_to_user(argp, &argv, sizeof(argv)))
781 		ret = -EFAULT;
782 	return ret;
783 }
784 
785 long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
786 {
787 	struct inode *inode = filp->f_dentry->d_inode;
788 	void __user *argp = (void __user *)arg;
789 
790 	switch (cmd) {
791 	case FS_IOC_GETFLAGS:
792 		return nilfs_ioctl_getflags(inode, argp);
793 	case FS_IOC_SETFLAGS:
794 		return nilfs_ioctl_setflags(inode, filp, argp);
795 	case FS_IOC_GETVERSION:
796 		return nilfs_ioctl_getversion(inode, argp);
797 	case NILFS_IOCTL_CHANGE_CPMODE:
798 		return nilfs_ioctl_change_cpmode(inode, filp, cmd, argp);
799 	case NILFS_IOCTL_DELETE_CHECKPOINT:
800 		return nilfs_ioctl_delete_checkpoint(inode, filp, cmd, argp);
801 	case NILFS_IOCTL_GET_CPINFO:
802 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
803 					    sizeof(struct nilfs_cpinfo),
804 					    nilfs_ioctl_do_get_cpinfo);
805 	case NILFS_IOCTL_GET_CPSTAT:
806 		return nilfs_ioctl_get_cpstat(inode, filp, cmd, argp);
807 	case NILFS_IOCTL_GET_SUINFO:
808 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
809 					    sizeof(struct nilfs_suinfo),
810 					    nilfs_ioctl_do_get_suinfo);
811 	case NILFS_IOCTL_GET_SUSTAT:
812 		return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
813 	case NILFS_IOCTL_GET_VINFO:
814 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
815 					    sizeof(struct nilfs_vinfo),
816 					    nilfs_ioctl_do_get_vinfo);
817 	case NILFS_IOCTL_GET_BDESCS:
818 		return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
819 	case NILFS_IOCTL_CLEAN_SEGMENTS:
820 		return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
821 	case NILFS_IOCTL_SYNC:
822 		return nilfs_ioctl_sync(inode, filp, cmd, argp);
823 	case NILFS_IOCTL_RESIZE:
824 		return nilfs_ioctl_resize(inode, filp, argp);
825 	case NILFS_IOCTL_SET_ALLOC_RANGE:
826 		return nilfs_ioctl_set_alloc_range(inode, argp);
827 	default:
828 		return -ENOTTY;
829 	}
830 }
831 
832 #ifdef CONFIG_COMPAT
833 long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
834 {
835 	switch (cmd) {
836 	case FS_IOC32_GETFLAGS:
837 		cmd = FS_IOC_GETFLAGS;
838 		break;
839 	case FS_IOC32_SETFLAGS:
840 		cmd = FS_IOC_SETFLAGS;
841 		break;
842 	case FS_IOC32_GETVERSION:
843 		cmd = FS_IOC_GETVERSION;
844 		break;
845 	default:
846 		return -ENOIOCTLCMD;
847 	}
848 	return nilfs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
849 }
850 #endif
851