xref: /linux/fs/nilfs2/ioctl.c (revision 3630400697a3d334a391c1dba1b601d852145f2c)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * NILFS ioctl operations.
4  *
5  * Copyright (C) 2007, 2008 Nippon Telegraph and Telephone Corporation.
6  *
7  * Written by Koji Sato.
8  */
9 
10 #include <linux/fs.h>
11 #include <linux/wait.h>
12 #include <linux/slab.h>
13 #include <linux/capability.h>	/* capable() */
14 #include <linux/uaccess.h>	/* copy_from_user(), copy_to_user() */
15 #include <linux/vmalloc.h>
16 #include <linux/compat.h>	/* compat_ptr() */
17 #include <linux/mount.h>	/* mnt_want_write_file(), mnt_drop_write_file() */
18 #include <linux/buffer_head.h>
19 #include <linux/fileattr.h>
20 #include <linux/string.h>
21 #include "nilfs.h"
22 #include "segment.h"
23 #include "bmap.h"
24 #include "cpfile.h"
25 #include "sufile.h"
26 #include "dat.h"
27 
28 /**
29  * nilfs_ioctl_wrap_copy - wrapping function of get/set metadata info
30  * @nilfs: nilfs object
31  * @argv: vector of arguments from userspace
32  * @dir: set of direction flags
33  * @dofunc: concrete function of get/set metadata info
34  *
35  * Description: nilfs_ioctl_wrap_copy() gets/sets metadata info by means of
36  * calling dofunc() function on the basis of @argv argument.
37  *
38  * Return Value: On success, 0 is returned and requested metadata info
39  * is copied into userspace. On error, one of the following
40  * negative error codes is returned.
41  *
42  * %-EINVAL - Invalid arguments from userspace.
43  *
44  * %-ENOMEM - Insufficient amount of memory available.
45  *
46  * %-EFAULT - Failure during execution of requested operation.
47  */
48 static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
49 				 struct nilfs_argv *argv, int dir,
50 				 ssize_t (*dofunc)(struct the_nilfs *,
51 						   __u64 *, int,
52 						   void *, size_t, size_t))
53 {
54 	void *buf;
55 	void __user *base = (void __user *)(unsigned long)argv->v_base;
56 	size_t maxmembs, total, n;
57 	ssize_t nr;
58 	int ret, i;
59 	__u64 pos, ppos;
60 
61 	if (argv->v_nmembs == 0)
62 		return 0;
63 
64 	if ((size_t)argv->v_size > PAGE_SIZE)
65 		return -EINVAL;
66 
67 	/*
68 	 * Reject pairs of a start item position (argv->v_index) and a
69 	 * total count (argv->v_nmembs) which leads position 'pos' to
70 	 * overflow by the increment at the end of the loop.
71 	 */
72 	if (argv->v_index > ~(__u64)0 - argv->v_nmembs)
73 		return -EINVAL;
74 
75 	buf = (void *)get_zeroed_page(GFP_NOFS);
76 	if (unlikely(!buf))
77 		return -ENOMEM;
78 	maxmembs = PAGE_SIZE / argv->v_size;
79 
80 	ret = 0;
81 	total = 0;
82 	pos = argv->v_index;
83 	for (i = 0; i < argv->v_nmembs; i += n) {
84 		n = (argv->v_nmembs - i < maxmembs) ?
85 			argv->v_nmembs - i : maxmembs;
86 		if ((dir & _IOC_WRITE) &&
87 		    copy_from_user(buf, base + argv->v_size * i,
88 				   argv->v_size * n)) {
89 			ret = -EFAULT;
90 			break;
91 		}
92 		ppos = pos;
93 		nr = dofunc(nilfs, &pos, argv->v_flags, buf, argv->v_size,
94 			       n);
95 		if (nr < 0) {
96 			ret = nr;
97 			break;
98 		}
99 		if ((dir & _IOC_READ) &&
100 		    copy_to_user(base + argv->v_size * i, buf,
101 				 argv->v_size * nr)) {
102 			ret = -EFAULT;
103 			break;
104 		}
105 		total += nr;
106 		if ((size_t)nr < n)
107 			break;
108 		if (pos == ppos)
109 			pos += n;
110 	}
111 	argv->v_nmembs = total;
112 
113 	free_pages((unsigned long)buf, 0);
114 	return ret;
115 }
116 
117 /**
118  * nilfs_fileattr_get - retrieve miscellaneous file attributes
119  * @dentry: the object to retrieve from
120  * @fa:     fileattr pointer
121  *
122  * Return: always 0 as success.
123  */
124 int nilfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
125 {
126 	struct inode *inode = d_inode(dentry);
127 
128 	fileattr_fill_flags(fa, NILFS_I(inode)->i_flags & FS_FL_USER_VISIBLE);
129 
130 	return 0;
131 }
132 
133 /**
134  * nilfs_fileattr_set - change miscellaneous file attributes
135  * @idmap:  idmap of the mount
136  * @dentry: the object to change
137  * @fa:     fileattr pointer
138  *
139  * Return: 0 on success, or a negative error code on failure.
140  */
141 int nilfs_fileattr_set(struct mnt_idmap *idmap,
142 		       struct dentry *dentry, struct fileattr *fa)
143 {
144 	struct inode *inode = d_inode(dentry);
145 	struct nilfs_transaction_info ti;
146 	unsigned int flags, oldflags;
147 	int ret;
148 
149 	if (fileattr_has_fsx(fa))
150 		return -EOPNOTSUPP;
151 
152 	flags = nilfs_mask_flags(inode->i_mode, fa->flags);
153 
154 	ret = nilfs_transaction_begin(inode->i_sb, &ti, 0);
155 	if (ret)
156 		return ret;
157 
158 	oldflags = NILFS_I(inode)->i_flags & ~FS_FL_USER_MODIFIABLE;
159 	NILFS_I(inode)->i_flags = oldflags | (flags & FS_FL_USER_MODIFIABLE);
160 
161 	nilfs_set_inode_flags(inode);
162 	inode_set_ctime_current(inode);
163 	if (IS_SYNC(inode))
164 		nilfs_set_transaction_flag(NILFS_TI_SYNC);
165 
166 	nilfs_mark_inode_dirty(inode);
167 	return nilfs_transaction_commit(inode->i_sb);
168 }
169 
170 /**
171  * nilfs_ioctl_getversion - get info about a file's version (generation number)
172  * @inode: inode object
173  * @argp:  userspace memory where the generation number of @inode is stored
174  *
175  * Return: 0 on success, or %-EFAULT on error.
176  */
177 static int nilfs_ioctl_getversion(struct inode *inode, void __user *argp)
178 {
179 	return put_user(inode->i_generation, (int __user *)argp);
180 }
181 
182 /**
183  * nilfs_ioctl_change_cpmode - change checkpoint mode (checkpoint/snapshot)
184  * @inode: inode object
185  * @filp: file object
186  * @cmd: ioctl's request code
187  * @argp: pointer on argument from userspace
188  *
189  * Description: nilfs_ioctl_change_cpmode() function changes mode of
190  * given checkpoint between checkpoint and snapshot state. This ioctl
191  * is used in chcp and mkcp utilities.
192  *
193  * Return Value: On success, 0 is returned and mode of a checkpoint is
194  * changed. On error, one of the following negative error codes
195  * is returned.
196  *
197  * %-EPERM - Operation not permitted.
198  *
199  * %-EFAULT - Failure during checkpoint mode changing.
200  */
201 static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
202 				     unsigned int cmd, void __user *argp)
203 {
204 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
205 	struct nilfs_transaction_info ti;
206 	struct nilfs_cpmode cpmode;
207 	int ret;
208 
209 	if (!capable(CAP_SYS_ADMIN))
210 		return -EPERM;
211 
212 	ret = mnt_want_write_file(filp);
213 	if (ret)
214 		return ret;
215 
216 	ret = -EFAULT;
217 	if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
218 		goto out;
219 
220 	mutex_lock(&nilfs->ns_snapshot_mount_mutex);
221 
222 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
223 	ret = nilfs_cpfile_change_cpmode(
224 		nilfs->ns_cpfile, cpmode.cm_cno, cpmode.cm_mode);
225 	if (unlikely(ret < 0))
226 		nilfs_transaction_abort(inode->i_sb);
227 	else
228 		nilfs_transaction_commit(inode->i_sb); /* never fails */
229 
230 	mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
231 out:
232 	mnt_drop_write_file(filp);
233 	return ret;
234 }
235 
236 /**
237  * nilfs_ioctl_delete_checkpoint - remove checkpoint
238  * @inode: inode object
239  * @filp: file object
240  * @cmd: ioctl's request code
241  * @argp: pointer on argument from userspace
242  *
243  * Description: nilfs_ioctl_delete_checkpoint() function removes
244  * checkpoint from NILFS2 file system. This ioctl is used in rmcp
245  * utility.
246  *
247  * Return Value: On success, 0 is returned and a checkpoint is
248  * removed. On error, one of the following negative error codes
249  * is returned.
250  *
251  * %-EPERM - Operation not permitted.
252  *
253  * %-EFAULT - Failure during checkpoint removing.
254  */
255 static int
256 nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
257 			      unsigned int cmd, void __user *argp)
258 {
259 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
260 	struct nilfs_transaction_info ti;
261 	__u64 cno;
262 	int ret;
263 
264 	if (!capable(CAP_SYS_ADMIN))
265 		return -EPERM;
266 
267 	ret = mnt_want_write_file(filp);
268 	if (ret)
269 		return ret;
270 
271 	ret = -EFAULT;
272 	if (copy_from_user(&cno, argp, sizeof(cno)))
273 		goto out;
274 
275 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
276 	ret = nilfs_cpfile_delete_checkpoint(nilfs->ns_cpfile, cno);
277 	if (unlikely(ret < 0))
278 		nilfs_transaction_abort(inode->i_sb);
279 	else
280 		nilfs_transaction_commit(inode->i_sb); /* never fails */
281 out:
282 	mnt_drop_write_file(filp);
283 	return ret;
284 }
285 
286 /**
287  * nilfs_ioctl_do_get_cpinfo - callback method getting info about checkpoints
288  * @nilfs: nilfs object
289  * @posp: pointer on array of checkpoint's numbers
290  * @flags: checkpoint mode (checkpoint or snapshot)
291  * @buf: buffer for storing checkponts' info
292  * @size: size in bytes of one checkpoint info item in array
293  * @nmembs: number of checkpoints in array (numbers and infos)
294  *
295  * Description: nilfs_ioctl_do_get_cpinfo() function returns info about
296  * requested checkpoints. The NILFS_IOCTL_GET_CPINFO ioctl is used in
297  * lscp utility and by nilfs_cleanerd daemon.
298  *
299  * Return value: count of nilfs_cpinfo structures in output buffer.
300  */
301 static ssize_t
302 nilfs_ioctl_do_get_cpinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
303 			  void *buf, size_t size, size_t nmembs)
304 {
305 	int ret;
306 
307 	down_read(&nilfs->ns_segctor_sem);
308 	ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
309 				      size, nmembs);
310 	up_read(&nilfs->ns_segctor_sem);
311 	return ret;
312 }
313 
314 /**
315  * nilfs_ioctl_get_cpstat - get checkpoints statistics
316  * @inode: inode object
317  * @filp: file object
318  * @cmd: ioctl's request code
319  * @argp: pointer on argument from userspace
320  *
321  * Description: nilfs_ioctl_get_cpstat() returns information about checkpoints.
322  * The NILFS_IOCTL_GET_CPSTAT ioctl is used by lscp, rmcp utilities
323  * and by nilfs_cleanerd daemon.
324  *
325  * Return Value: On success, 0 is returned, and checkpoints information is
326  * copied into userspace pointer @argp. On error, one of the following
327  * negative error codes is returned.
328  *
329  * %-EIO - I/O error.
330  *
331  * %-ENOMEM - Insufficient amount of memory available.
332  *
333  * %-EFAULT - Failure during getting checkpoints statistics.
334  */
335 static int nilfs_ioctl_get_cpstat(struct inode *inode, struct file *filp,
336 				  unsigned int cmd, void __user *argp)
337 {
338 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
339 	struct nilfs_cpstat cpstat;
340 	int ret;
341 
342 	down_read(&nilfs->ns_segctor_sem);
343 	ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
344 	up_read(&nilfs->ns_segctor_sem);
345 	if (ret < 0)
346 		return ret;
347 
348 	if (copy_to_user(argp, &cpstat, sizeof(cpstat)))
349 		ret = -EFAULT;
350 	return ret;
351 }
352 
353 /**
354  * nilfs_ioctl_do_get_suinfo - callback method getting segment usage info
355  * @nilfs: nilfs object
356  * @posp: pointer on array of segment numbers
357  * @flags: *not used*
358  * @buf: buffer for storing suinfo array
359  * @size: size in bytes of one suinfo item in array
360  * @nmembs: count of segment numbers and suinfos in array
361  *
362  * Description: nilfs_ioctl_do_get_suinfo() function returns segment usage
363  * info about requested segments. The NILFS_IOCTL_GET_SUINFO ioctl is used
364  * in lssu, nilfs_resize utilities and by nilfs_cleanerd daemon.
365  *
366  * Return value: count of nilfs_suinfo structures in output buffer.
367  */
368 static ssize_t
369 nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
370 			  void *buf, size_t size, size_t nmembs)
371 {
372 	int ret;
373 
374 	down_read(&nilfs->ns_segctor_sem);
375 	ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
376 				      nmembs);
377 	up_read(&nilfs->ns_segctor_sem);
378 	return ret;
379 }
380 
381 /**
382  * nilfs_ioctl_get_sustat - get segment usage statistics
383  * @inode: inode object
384  * @filp: file object
385  * @cmd: ioctl's request code
386  * @argp: pointer on argument from userspace
387  *
388  * Description: nilfs_ioctl_get_sustat() returns segment usage statistics.
389  * The NILFS_IOCTL_GET_SUSTAT ioctl is used in lssu, nilfs_resize utilities
390  * and by nilfs_cleanerd daemon.
391  *
392  * Return Value: On success, 0 is returned, and segment usage information is
393  * copied into userspace pointer @argp. On error, one of the following
394  * negative error codes is returned.
395  *
396  * %-EIO - I/O error.
397  *
398  * %-ENOMEM - Insufficient amount of memory available.
399  *
400  * %-EFAULT - Failure during getting segment usage statistics.
401  */
402 static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
403 				  unsigned int cmd, void __user *argp)
404 {
405 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
406 	struct nilfs_sustat sustat;
407 	int ret;
408 
409 	down_read(&nilfs->ns_segctor_sem);
410 	ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
411 	up_read(&nilfs->ns_segctor_sem);
412 	if (ret < 0)
413 		return ret;
414 
415 	if (copy_to_user(argp, &sustat, sizeof(sustat)))
416 		ret = -EFAULT;
417 	return ret;
418 }
419 
420 /**
421  * nilfs_ioctl_do_get_vinfo - callback method getting virtual blocks info
422  * @nilfs: nilfs object
423  * @posp: *not used*
424  * @flags: *not used*
425  * @buf: buffer for storing array of nilfs_vinfo structures
426  * @size: size in bytes of one vinfo item in array
427  * @nmembs: count of vinfos in array
428  *
429  * Description: nilfs_ioctl_do_get_vinfo() function returns information
430  * on virtual block addresses. The NILFS_IOCTL_GET_VINFO ioctl is used
431  * by nilfs_cleanerd daemon.
432  *
433  * Return value: count of nilfs_vinfo structures in output buffer.
434  */
435 static ssize_t
436 nilfs_ioctl_do_get_vinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
437 			 void *buf, size_t size, size_t nmembs)
438 {
439 	int ret;
440 
441 	down_read(&nilfs->ns_segctor_sem);
442 	ret = nilfs_dat_get_vinfo(nilfs->ns_dat, buf, size, nmembs);
443 	up_read(&nilfs->ns_segctor_sem);
444 	return ret;
445 }
446 
447 /**
448  * nilfs_ioctl_do_get_bdescs - callback method getting disk block descriptors
449  * @nilfs: nilfs object
450  * @posp: *not used*
451  * @flags: *not used*
452  * @buf: buffer for storing array of nilfs_bdesc structures
453  * @size: size in bytes of one bdesc item in array
454  * @nmembs: count of bdescs in array
455  *
456  * Description: nilfs_ioctl_do_get_bdescs() function returns information
457  * about descriptors of disk block numbers. The NILFS_IOCTL_GET_BDESCS ioctl
458  * is used by nilfs_cleanerd daemon.
459  *
460  * Return value: count of nilfs_bdescs structures in output buffer.
461  */
462 static ssize_t
463 nilfs_ioctl_do_get_bdescs(struct the_nilfs *nilfs, __u64 *posp, int flags,
464 			  void *buf, size_t size, size_t nmembs)
465 {
466 	struct nilfs_bmap *bmap = NILFS_I(nilfs->ns_dat)->i_bmap;
467 	struct nilfs_bdesc *bdescs = buf;
468 	int ret, i;
469 
470 	down_read(&nilfs->ns_segctor_sem);
471 	for (i = 0; i < nmembs; i++) {
472 		ret = nilfs_bmap_lookup_at_level(bmap,
473 						 bdescs[i].bd_offset,
474 						 bdescs[i].bd_level + 1,
475 						 &bdescs[i].bd_blocknr);
476 		if (ret < 0) {
477 			if (ret != -ENOENT) {
478 				up_read(&nilfs->ns_segctor_sem);
479 				return ret;
480 			}
481 			bdescs[i].bd_blocknr = 0;
482 		}
483 	}
484 	up_read(&nilfs->ns_segctor_sem);
485 	return nmembs;
486 }
487 
488 /**
489  * nilfs_ioctl_get_bdescs - get disk block descriptors
490  * @inode: inode object
491  * @filp: file object
492  * @cmd: ioctl's request code
493  * @argp: pointer on argument from userspace
494  *
495  * Description: nilfs_ioctl_do_get_bdescs() function returns information
496  * about descriptors of disk block numbers. The NILFS_IOCTL_GET_BDESCS ioctl
497  * is used by nilfs_cleanerd daemon.
498  *
499  * Return Value: On success, 0 is returned, and disk block descriptors are
500  * copied into userspace pointer @argp. On error, one of the following
501  * negative error codes is returned.
502  *
503  * %-EINVAL - Invalid arguments from userspace.
504  *
505  * %-EIO - I/O error.
506  *
507  * %-ENOMEM - Insufficient amount of memory available.
508  *
509  * %-EFAULT - Failure during getting disk block descriptors.
510  */
511 static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp,
512 				  unsigned int cmd, void __user *argp)
513 {
514 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
515 	struct nilfs_argv argv;
516 	int ret;
517 
518 	if (copy_from_user(&argv, argp, sizeof(argv)))
519 		return -EFAULT;
520 
521 	if (argv.v_size != sizeof(struct nilfs_bdesc))
522 		return -EINVAL;
523 
524 	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
525 				    nilfs_ioctl_do_get_bdescs);
526 	if (ret < 0)
527 		return ret;
528 
529 	if (copy_to_user(argp, &argv, sizeof(argv)))
530 		ret = -EFAULT;
531 	return ret;
532 }
533 
534 /**
535  * nilfs_ioctl_move_inode_block - prepare data/node block for moving by GC
536  * @inode: inode object
537  * @vdesc: descriptor of virtual block number
538  * @buffers: list of moving buffers
539  *
540  * Description: nilfs_ioctl_move_inode_block() function registers data/node
541  * buffer in the GC pagecache and submit read request.
542  *
543  * Return Value: On success, 0 is returned. On error, one of the following
544  * negative error codes is returned.
545  *
546  * %-EIO - I/O error.
547  *
548  * %-ENOMEM - Insufficient amount of memory available.
549  *
550  * %-ENOENT - Requested block doesn't exist.
551  *
552  * %-EEXIST - Blocks conflict is detected.
553  */
554 static int nilfs_ioctl_move_inode_block(struct inode *inode,
555 					struct nilfs_vdesc *vdesc,
556 					struct list_head *buffers)
557 {
558 	struct buffer_head *bh;
559 	int ret;
560 
561 	if (vdesc->vd_flags == 0)
562 		ret = nilfs_gccache_submit_read_data(
563 			inode, vdesc->vd_offset, vdesc->vd_blocknr,
564 			vdesc->vd_vblocknr, &bh);
565 	else
566 		ret = nilfs_gccache_submit_read_node(
567 			inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh);
568 
569 	if (unlikely(ret < 0)) {
570 		if (ret == -ENOENT)
571 			nilfs_crit(inode->i_sb,
572 				   "%s: invalid virtual block address (%s): ino=%llu, cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu",
573 				   __func__, vdesc->vd_flags ? "node" : "data",
574 				   (unsigned long long)vdesc->vd_ino,
575 				   (unsigned long long)vdesc->vd_cno,
576 				   (unsigned long long)vdesc->vd_offset,
577 				   (unsigned long long)vdesc->vd_blocknr,
578 				   (unsigned long long)vdesc->vd_vblocknr);
579 		return ret;
580 	}
581 	if (unlikely(!list_empty(&bh->b_assoc_buffers))) {
582 		nilfs_crit(inode->i_sb,
583 			   "%s: conflicting %s buffer: ino=%llu, cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu",
584 			   __func__, vdesc->vd_flags ? "node" : "data",
585 			   (unsigned long long)vdesc->vd_ino,
586 			   (unsigned long long)vdesc->vd_cno,
587 			   (unsigned long long)vdesc->vd_offset,
588 			   (unsigned long long)vdesc->vd_blocknr,
589 			   (unsigned long long)vdesc->vd_vblocknr);
590 		brelse(bh);
591 		return -EEXIST;
592 	}
593 	list_add_tail(&bh->b_assoc_buffers, buffers);
594 	return 0;
595 }
596 
597 /**
598  * nilfs_ioctl_move_blocks - move valid inode's blocks during garbage collection
599  * @sb: superblock object
600  * @argv: vector of arguments from userspace
601  * @buf: array of nilfs_vdesc structures
602  *
603  * Description: nilfs_ioctl_move_blocks() function reads valid data/node
604  * blocks that garbage collector specified with the array of nilfs_vdesc
605  * structures and stores them into page caches of GC inodes.
606  *
607  * Return Value: Number of processed nilfs_vdesc structures or
608  * error code, otherwise.
609  */
610 static int nilfs_ioctl_move_blocks(struct super_block *sb,
611 				   struct nilfs_argv *argv, void *buf)
612 {
613 	size_t nmembs = argv->v_nmembs;
614 	struct the_nilfs *nilfs = sb->s_fs_info;
615 	struct inode *inode;
616 	struct nilfs_vdesc *vdesc;
617 	struct buffer_head *bh, *n;
618 	LIST_HEAD(buffers);
619 	ino_t ino;
620 	__u64 cno;
621 	int i, ret;
622 
623 	for (i = 0, vdesc = buf; i < nmembs; ) {
624 		ino = vdesc->vd_ino;
625 		cno = vdesc->vd_cno;
626 		inode = nilfs_iget_for_gc(sb, ino, cno);
627 		if (IS_ERR(inode)) {
628 			ret = PTR_ERR(inode);
629 			goto failed;
630 		}
631 		if (list_empty(&NILFS_I(inode)->i_dirty)) {
632 			/*
633 			 * Add the inode to GC inode list. Garbage Collection
634 			 * is serialized and no two processes manipulate the
635 			 * list simultaneously.
636 			 */
637 			igrab(inode);
638 			list_add(&NILFS_I(inode)->i_dirty,
639 				 &nilfs->ns_gc_inodes);
640 		}
641 
642 		do {
643 			ret = nilfs_ioctl_move_inode_block(inode, vdesc,
644 							   &buffers);
645 			if (unlikely(ret < 0)) {
646 				iput(inode);
647 				goto failed;
648 			}
649 			vdesc++;
650 		} while (++i < nmembs &&
651 			 vdesc->vd_ino == ino && vdesc->vd_cno == cno);
652 
653 		iput(inode); /* The inode still remains in GC inode list */
654 	}
655 
656 	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
657 		ret = nilfs_gccache_wait_and_mark_dirty(bh);
658 		if (unlikely(ret < 0)) {
659 			WARN_ON(ret == -EEXIST);
660 			goto failed;
661 		}
662 		list_del_init(&bh->b_assoc_buffers);
663 		brelse(bh);
664 	}
665 	return nmembs;
666 
667  failed:
668 	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
669 		list_del_init(&bh->b_assoc_buffers);
670 		brelse(bh);
671 	}
672 	return ret;
673 }
674 
675 /**
676  * nilfs_ioctl_delete_checkpoints - delete checkpoints
677  * @nilfs: nilfs object
678  * @argv: vector of arguments from userspace
679  * @buf: array of periods of checkpoints numbers
680  *
681  * Description: nilfs_ioctl_delete_checkpoints() function deletes checkpoints
682  * in the period from p_start to p_end, excluding p_end itself. The checkpoints
683  * which have been already deleted are ignored.
684  *
685  * Return Value: Number of processed nilfs_period structures or
686  * error code, otherwise.
687  *
688  * %-EIO - I/O error.
689  *
690  * %-ENOMEM - Insufficient amount of memory available.
691  *
692  * %-EINVAL - invalid checkpoints.
693  */
694 static int nilfs_ioctl_delete_checkpoints(struct the_nilfs *nilfs,
695 					  struct nilfs_argv *argv, void *buf)
696 {
697 	size_t nmembs = argv->v_nmembs;
698 	struct inode *cpfile = nilfs->ns_cpfile;
699 	struct nilfs_period *periods = buf;
700 	int ret, i;
701 
702 	for (i = 0; i < nmembs; i++) {
703 		ret = nilfs_cpfile_delete_checkpoints(
704 			cpfile, periods[i].p_start, periods[i].p_end);
705 		if (ret < 0)
706 			return ret;
707 	}
708 	return nmembs;
709 }
710 
711 /**
712  * nilfs_ioctl_free_vblocknrs - free virtual block numbers
713  * @nilfs: nilfs object
714  * @argv: vector of arguments from userspace
715  * @buf: array of virtual block numbers
716  *
717  * Description: nilfs_ioctl_free_vblocknrs() function frees
718  * the virtual block numbers specified by @buf and @argv->v_nmembs.
719  *
720  * Return Value: Number of processed virtual block numbers or
721  * error code, otherwise.
722  *
723  * %-EIO - I/O error.
724  *
725  * %-ENOMEM - Insufficient amount of memory available.
726  *
727  * %-ENOENT - The virtual block number have not been allocated.
728  */
729 static int nilfs_ioctl_free_vblocknrs(struct the_nilfs *nilfs,
730 				      struct nilfs_argv *argv, void *buf)
731 {
732 	size_t nmembs = argv->v_nmembs;
733 	int ret;
734 
735 	ret = nilfs_dat_freev(nilfs->ns_dat, buf, nmembs);
736 
737 	return (ret < 0) ? ret : nmembs;
738 }
739 
740 /**
741  * nilfs_ioctl_mark_blocks_dirty - mark blocks dirty
742  * @nilfs: nilfs object
743  * @argv: vector of arguments from userspace
744  * @buf: array of block descriptors
745  *
746  * Description: nilfs_ioctl_mark_blocks_dirty() function marks
747  * metadata file or data blocks as dirty.
748  *
749  * Return Value: Number of processed block descriptors or
750  * error code, otherwise.
751  *
752  * %-ENOMEM - Insufficient memory available.
753  *
754  * %-EIO - I/O error
755  *
756  * %-ENOENT - the specified block does not exist (hole block)
757  */
758 static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs,
759 					 struct nilfs_argv *argv, void *buf)
760 {
761 	size_t nmembs = argv->v_nmembs;
762 	struct nilfs_bmap *bmap = NILFS_I(nilfs->ns_dat)->i_bmap;
763 	struct nilfs_bdesc *bdescs = buf;
764 	struct buffer_head *bh;
765 	int ret, i;
766 
767 	for (i = 0; i < nmembs; i++) {
768 		/* XXX: use macro or inline func to check liveness */
769 		ret = nilfs_bmap_lookup_at_level(bmap,
770 						 bdescs[i].bd_offset,
771 						 bdescs[i].bd_level + 1,
772 						 &bdescs[i].bd_blocknr);
773 		if (ret < 0) {
774 			if (ret != -ENOENT)
775 				return ret;
776 			bdescs[i].bd_blocknr = 0;
777 		}
778 		if (bdescs[i].bd_blocknr != bdescs[i].bd_oblocknr)
779 			/* skip dead block */
780 			continue;
781 		if (bdescs[i].bd_level == 0) {
782 			ret = nilfs_mdt_get_block(nilfs->ns_dat,
783 						  bdescs[i].bd_offset,
784 						  false, NULL, &bh);
785 			if (unlikely(ret)) {
786 				WARN_ON(ret == -ENOENT);
787 				return ret;
788 			}
789 			mark_buffer_dirty(bh);
790 			nilfs_mdt_mark_dirty(nilfs->ns_dat);
791 			put_bh(bh);
792 		} else {
793 			ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
794 					      bdescs[i].bd_level);
795 			if (ret < 0) {
796 				WARN_ON(ret == -ENOENT);
797 				return ret;
798 			}
799 		}
800 	}
801 	return nmembs;
802 }
803 
804 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
805 				       struct nilfs_argv *argv, void **kbufs)
806 {
807 	const char *msg;
808 	int ret;
809 
810 	ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
811 	if (ret < 0) {
812 		/*
813 		 * can safely abort because checkpoints can be removed
814 		 * independently.
815 		 */
816 		msg = "cannot delete checkpoints";
817 		goto failed;
818 	}
819 	ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], kbufs[2]);
820 	if (ret < 0) {
821 		/*
822 		 * can safely abort because DAT file is updated atomically
823 		 * using a copy-on-write technique.
824 		 */
825 		msg = "cannot delete virtual blocks from DAT file";
826 		goto failed;
827 	}
828 	ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], kbufs[3]);
829 	if (ret < 0) {
830 		/*
831 		 * can safely abort because the operation is nondestructive.
832 		 */
833 		msg = "cannot mark copying blocks dirty";
834 		goto failed;
835 	}
836 	return 0;
837 
838  failed:
839 	nilfs_err(nilfs->ns_sb, "error %d preparing GC: %s", ret, msg);
840 	return ret;
841 }
842 
843 /**
844  * nilfs_ioctl_clean_segments - clean segments
845  * @inode: inode object
846  * @filp: file object
847  * @cmd: ioctl's request code
848  * @argp: pointer on argument from userspace
849  *
850  * Description: nilfs_ioctl_clean_segments() function makes garbage
851  * collection operation in the environment of requested parameters
852  * from userspace. The NILFS_IOCTL_CLEAN_SEGMENTS ioctl is used by
853  * nilfs_cleanerd daemon.
854  *
855  * Return Value: On success, 0 is returned or error code, otherwise.
856  */
857 static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
858 				      unsigned int cmd, void __user *argp)
859 {
860 	struct nilfs_argv argv[5];
861 	static const size_t argsz[5] = {
862 		sizeof(struct nilfs_vdesc),
863 		sizeof(struct nilfs_period),
864 		sizeof(__u64),
865 		sizeof(struct nilfs_bdesc),
866 		sizeof(__u64),
867 	};
868 	void __user *base;
869 	void *kbufs[5];
870 	struct the_nilfs *nilfs;
871 	size_t len, nsegs;
872 	int n, ret;
873 
874 	if (!capable(CAP_SYS_ADMIN))
875 		return -EPERM;
876 
877 	ret = mnt_want_write_file(filp);
878 	if (ret)
879 		return ret;
880 
881 	ret = -EFAULT;
882 	if (copy_from_user(argv, argp, sizeof(argv)))
883 		goto out;
884 
885 	ret = -EINVAL;
886 	nsegs = argv[4].v_nmembs;
887 	if (argv[4].v_size != argsz[4])
888 		goto out;
889 
890 	/*
891 	 * argv[4] points to segment numbers this ioctl cleans.  We
892 	 * use kmalloc() for its buffer because the memory used for the
893 	 * segment numbers is small enough.
894 	 */
895 	kbufs[4] = memdup_array_user((void __user *)(unsigned long)argv[4].v_base,
896 				     nsegs, sizeof(__u64));
897 	if (IS_ERR(kbufs[4])) {
898 		ret = PTR_ERR(kbufs[4]);
899 		goto out;
900 	}
901 	nilfs = inode->i_sb->s_fs_info;
902 
903 	for (n = 0; n < 4; n++) {
904 		ret = -EINVAL;
905 		if (argv[n].v_size != argsz[n])
906 			goto out_free;
907 
908 		if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
909 			goto out_free;
910 
911 		if (argv[n].v_nmembs >= UINT_MAX / argv[n].v_size)
912 			goto out_free;
913 
914 		len = argv[n].v_size * argv[n].v_nmembs;
915 		base = (void __user *)(unsigned long)argv[n].v_base;
916 		if (len == 0) {
917 			kbufs[n] = NULL;
918 			continue;
919 		}
920 
921 		kbufs[n] = vmalloc(len);
922 		if (!kbufs[n]) {
923 			ret = -ENOMEM;
924 			goto out_free;
925 		}
926 		if (copy_from_user(kbufs[n], base, len)) {
927 			ret = -EFAULT;
928 			vfree(kbufs[n]);
929 			goto out_free;
930 		}
931 	}
932 
933 	/*
934 	 * nilfs_ioctl_move_blocks() will call nilfs_iget_for_gc(),
935 	 * which will operates an inode list without blocking.
936 	 * To protect the list from concurrent operations,
937 	 * nilfs_ioctl_move_blocks should be atomic operation.
938 	 */
939 	if (test_and_set_bit(THE_NILFS_GC_RUNNING, &nilfs->ns_flags)) {
940 		ret = -EBUSY;
941 		goto out_free;
942 	}
943 
944 	ret = nilfs_ioctl_move_blocks(inode->i_sb, &argv[0], kbufs[0]);
945 	if (ret < 0) {
946 		nilfs_err(inode->i_sb,
947 			  "error %d preparing GC: cannot read source blocks",
948 			  ret);
949 	} else {
950 		if (nilfs_sb_need_update(nilfs))
951 			set_nilfs_discontinued(nilfs);
952 		ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
953 	}
954 
955 	nilfs_remove_all_gcinodes(nilfs);
956 	clear_nilfs_gc_running(nilfs);
957 
958 out_free:
959 	while (--n >= 0)
960 		vfree(kbufs[n]);
961 	kfree(kbufs[4]);
962 out:
963 	mnt_drop_write_file(filp);
964 	return ret;
965 }
966 
967 /**
968  * nilfs_ioctl_sync - make a checkpoint
969  * @inode: inode object
970  * @filp: file object
971  * @cmd: ioctl's request code
972  * @argp: pointer on argument from userspace
973  *
974  * Description: nilfs_ioctl_sync() function constructs a logical segment
975  * for checkpointing.  This function guarantees that all modified data
976  * and metadata are written out to the device when it successfully
977  * returned.
978  *
979  * Return Value: On success, 0 is retured. On errors, one of the following
980  * negative error code is returned.
981  *
982  * %-EROFS - Read only filesystem.
983  *
984  * %-EIO - I/O error
985  *
986  * %-ENOSPC - No space left on device (only in a panic state).
987  *
988  * %-ERESTARTSYS - Interrupted.
989  *
990  * %-ENOMEM - Insufficient memory available.
991  *
992  * %-EFAULT - Failure during execution of requested operation.
993  */
994 static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
995 			    unsigned int cmd, void __user *argp)
996 {
997 	__u64 cno;
998 	int ret;
999 	struct the_nilfs *nilfs;
1000 
1001 	ret = nilfs_construct_segment(inode->i_sb);
1002 	if (ret < 0)
1003 		return ret;
1004 
1005 	nilfs = inode->i_sb->s_fs_info;
1006 	ret = nilfs_flush_device(nilfs);
1007 	if (ret < 0)
1008 		return ret;
1009 
1010 	if (argp != NULL) {
1011 		down_read(&nilfs->ns_segctor_sem);
1012 		cno = nilfs->ns_cno - 1;
1013 		up_read(&nilfs->ns_segctor_sem);
1014 		if (copy_to_user(argp, &cno, sizeof(cno)))
1015 			return -EFAULT;
1016 	}
1017 	return 0;
1018 }
1019 
1020 /**
1021  * nilfs_ioctl_resize - resize NILFS2 volume
1022  * @inode: inode object
1023  * @filp: file object
1024  * @argp: pointer on argument from userspace
1025  *
1026  * Return Value: On success, 0 is returned or error code, otherwise.
1027  */
1028 static int nilfs_ioctl_resize(struct inode *inode, struct file *filp,
1029 			      void __user *argp)
1030 {
1031 	__u64 newsize;
1032 	int ret = -EPERM;
1033 
1034 	if (!capable(CAP_SYS_ADMIN))
1035 		goto out;
1036 
1037 	ret = mnt_want_write_file(filp);
1038 	if (ret)
1039 		goto out;
1040 
1041 	ret = -EFAULT;
1042 	if (copy_from_user(&newsize, argp, sizeof(newsize)))
1043 		goto out_drop_write;
1044 
1045 	ret = nilfs_resize_fs(inode->i_sb, newsize);
1046 
1047 out_drop_write:
1048 	mnt_drop_write_file(filp);
1049 out:
1050 	return ret;
1051 }
1052 
1053 /**
1054  * nilfs_ioctl_trim_fs() - trim ioctl handle function
1055  * @inode: inode object
1056  * @argp: pointer on argument from userspace
1057  *
1058  * Description: nilfs_ioctl_trim_fs is the FITRIM ioctl handle function. It
1059  * checks the arguments from userspace and calls nilfs_sufile_trim_fs, which
1060  * performs the actual trim operation.
1061  *
1062  * Return Value: On success, 0 is returned or negative error code, otherwise.
1063  */
1064 static int nilfs_ioctl_trim_fs(struct inode *inode, void __user *argp)
1065 {
1066 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1067 	struct fstrim_range range;
1068 	int ret;
1069 
1070 	if (!capable(CAP_SYS_ADMIN))
1071 		return -EPERM;
1072 
1073 	if (!bdev_max_discard_sectors(nilfs->ns_bdev))
1074 		return -EOPNOTSUPP;
1075 
1076 	if (copy_from_user(&range, argp, sizeof(range)))
1077 		return -EFAULT;
1078 
1079 	range.minlen = max_t(u64, range.minlen,
1080 			     bdev_discard_granularity(nilfs->ns_bdev));
1081 
1082 	down_read(&nilfs->ns_segctor_sem);
1083 	ret = nilfs_sufile_trim_fs(nilfs->ns_sufile, &range);
1084 	up_read(&nilfs->ns_segctor_sem);
1085 
1086 	if (ret < 0)
1087 		return ret;
1088 
1089 	if (copy_to_user(argp, &range, sizeof(range)))
1090 		return -EFAULT;
1091 
1092 	return 0;
1093 }
1094 
1095 /**
1096  * nilfs_ioctl_set_alloc_range - limit range of segments to be allocated
1097  * @inode: inode object
1098  * @argp: pointer on argument from userspace
1099  *
1100  * Description: nilfs_ioctl_set_alloc_range() function defines lower limit
1101  * of segments in bytes and upper limit of segments in bytes.
1102  * The NILFS_IOCTL_SET_ALLOC_RANGE is used by nilfs_resize utility.
1103  *
1104  * Return Value: On success, 0 is returned or error code, otherwise.
1105  */
1106 static int nilfs_ioctl_set_alloc_range(struct inode *inode, void __user *argp)
1107 {
1108 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1109 	__u64 range[2];
1110 	__u64 minseg, maxseg;
1111 	unsigned long segbytes;
1112 	int ret = -EPERM;
1113 
1114 	if (!capable(CAP_SYS_ADMIN))
1115 		goto out;
1116 
1117 	ret = -EFAULT;
1118 	if (copy_from_user(range, argp, sizeof(__u64[2])))
1119 		goto out;
1120 
1121 	ret = -ERANGE;
1122 	if (range[1] > bdev_nr_bytes(inode->i_sb->s_bdev))
1123 		goto out;
1124 
1125 	segbytes = nilfs->ns_blocks_per_segment * nilfs->ns_blocksize;
1126 
1127 	minseg = range[0] + segbytes - 1;
1128 	minseg = div64_ul(minseg, segbytes);
1129 
1130 	if (range[1] < 4096)
1131 		goto out;
1132 
1133 	maxseg = NILFS_SB2_OFFSET_BYTES(range[1]);
1134 	if (maxseg < segbytes)
1135 		goto out;
1136 
1137 	maxseg = div64_ul(maxseg, segbytes);
1138 	maxseg--;
1139 
1140 	ret = nilfs_sufile_set_alloc_range(nilfs->ns_sufile, minseg, maxseg);
1141 out:
1142 	return ret;
1143 }
1144 
1145 /**
1146  * nilfs_ioctl_get_info - wrapping function of get metadata info
1147  * @inode: inode object
1148  * @filp: file object
1149  * @cmd: ioctl's request code
1150  * @argp: pointer on argument from userspace
1151  * @membsz: size of an item in bytes
1152  * @dofunc: concrete function of getting metadata info
1153  *
1154  * Description: nilfs_ioctl_get_info() gets metadata info by means of
1155  * calling dofunc() function.
1156  *
1157  * Return Value: On success, 0 is returned and requested metadata info
1158  * is copied into userspace. On error, one of the following
1159  * negative error codes is returned.
1160  *
1161  * %-EINVAL - Invalid arguments from userspace.
1162  *
1163  * %-ENOMEM - Insufficient amount of memory available.
1164  *
1165  * %-EFAULT - Failure during execution of requested operation.
1166  */
1167 static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
1168 				unsigned int cmd, void __user *argp,
1169 				size_t membsz,
1170 				ssize_t (*dofunc)(struct the_nilfs *,
1171 						  __u64 *, int,
1172 						  void *, size_t, size_t))
1173 
1174 {
1175 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1176 	struct nilfs_argv argv;
1177 	int ret;
1178 
1179 	if (copy_from_user(&argv, argp, sizeof(argv)))
1180 		return -EFAULT;
1181 
1182 	if (argv.v_size < membsz)
1183 		return -EINVAL;
1184 
1185 	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
1186 	if (ret < 0)
1187 		return ret;
1188 
1189 	if (copy_to_user(argp, &argv, sizeof(argv)))
1190 		ret = -EFAULT;
1191 	return ret;
1192 }
1193 
1194 /**
1195  * nilfs_ioctl_set_suinfo - set segment usage info
1196  * @inode: inode object
1197  * @filp: file object
1198  * @cmd: ioctl's request code
1199  * @argp: pointer on argument from userspace
1200  *
1201  * Description: Expects an array of nilfs_suinfo_update structures
1202  * encapsulated in nilfs_argv and updates the segment usage info
1203  * according to the flags in nilfs_suinfo_update.
1204  *
1205  * Return Value: On success, 0 is returned. On error, one of the
1206  * following negative error codes is returned.
1207  *
1208  * %-EPERM - Not enough permissions
1209  *
1210  * %-EFAULT - Error copying input data
1211  *
1212  * %-EIO - I/O error.
1213  *
1214  * %-ENOMEM - Insufficient amount of memory available.
1215  *
1216  * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
1217  */
1218 static int nilfs_ioctl_set_suinfo(struct inode *inode, struct file *filp,
1219 				unsigned int cmd, void __user *argp)
1220 {
1221 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1222 	struct nilfs_transaction_info ti;
1223 	struct nilfs_argv argv;
1224 	size_t len;
1225 	void __user *base;
1226 	void *kbuf;
1227 	int ret;
1228 
1229 	if (!capable(CAP_SYS_ADMIN))
1230 		return -EPERM;
1231 
1232 	ret = mnt_want_write_file(filp);
1233 	if (ret)
1234 		return ret;
1235 
1236 	ret = -EFAULT;
1237 	if (copy_from_user(&argv, argp, sizeof(argv)))
1238 		goto out;
1239 
1240 	ret = -EINVAL;
1241 	if (argv.v_size < sizeof(struct nilfs_suinfo_update))
1242 		goto out;
1243 
1244 	if (argv.v_nmembs > nilfs->ns_nsegments)
1245 		goto out;
1246 
1247 	if (argv.v_nmembs >= UINT_MAX / argv.v_size)
1248 		goto out;
1249 
1250 	len = argv.v_size * argv.v_nmembs;
1251 	if (!len) {
1252 		ret = 0;
1253 		goto out;
1254 	}
1255 
1256 	base = (void __user *)(unsigned long)argv.v_base;
1257 	kbuf = vmalloc(len);
1258 	if (!kbuf) {
1259 		ret = -ENOMEM;
1260 		goto out;
1261 	}
1262 
1263 	if (copy_from_user(kbuf, base, len)) {
1264 		ret = -EFAULT;
1265 		goto out_free;
1266 	}
1267 
1268 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
1269 	ret = nilfs_sufile_set_suinfo(nilfs->ns_sufile, kbuf, argv.v_size,
1270 			argv.v_nmembs);
1271 	if (unlikely(ret < 0))
1272 		nilfs_transaction_abort(inode->i_sb);
1273 	else
1274 		nilfs_transaction_commit(inode->i_sb); /* never fails */
1275 
1276 out_free:
1277 	vfree(kbuf);
1278 out:
1279 	mnt_drop_write_file(filp);
1280 	return ret;
1281 }
1282 
1283 /**
1284  * nilfs_ioctl_get_fslabel - get the volume name of the file system
1285  * @sb:   super block instance
1286  * @argp: pointer to userspace memory where the volume name should be stored
1287  *
1288  * Return: 0 on success, %-EFAULT if copying to userspace memory fails.
1289  */
1290 static int nilfs_ioctl_get_fslabel(struct super_block *sb, void __user *argp)
1291 {
1292 	struct the_nilfs *nilfs = sb->s_fs_info;
1293 	char label[NILFS_MAX_VOLUME_NAME + 1];
1294 
1295 	BUILD_BUG_ON(NILFS_MAX_VOLUME_NAME >= FSLABEL_MAX);
1296 
1297 	down_read(&nilfs->ns_sem);
1298 	memtostr_pad(label, nilfs->ns_sbp[0]->s_volume_name);
1299 	up_read(&nilfs->ns_sem);
1300 
1301 	if (copy_to_user(argp, label, sizeof(label)))
1302 		return -EFAULT;
1303 	return 0;
1304 }
1305 
1306 /**
1307  * nilfs_ioctl_set_fslabel - set the volume name of the file system
1308  * @sb:   super block instance
1309  * @filp: file object
1310  * @argp: pointer to userspace memory that contains the volume name
1311  *
1312  * Return: 0 on success, or the following negative error code on failure.
1313  * * %-EFAULT	- Error copying input data.
1314  * * %-EINVAL	- Label length exceeds record size in superblock.
1315  * * %-EIO	- I/O error.
1316  * * %-EPERM	- Operation not permitted (insufficient permissions).
1317  * * %-EROFS	- Read only file system.
1318  */
1319 static int nilfs_ioctl_set_fslabel(struct super_block *sb, struct file *filp,
1320 				   void __user *argp)
1321 {
1322 	char label[NILFS_MAX_VOLUME_NAME + 1];
1323 	struct the_nilfs *nilfs = sb->s_fs_info;
1324 	struct nilfs_super_block **sbp;
1325 	size_t len;
1326 	int ret;
1327 
1328 	if (!capable(CAP_SYS_ADMIN))
1329 		return -EPERM;
1330 
1331 	ret = mnt_want_write_file(filp);
1332 	if (ret)
1333 		return ret;
1334 
1335 	if (copy_from_user(label, argp, NILFS_MAX_VOLUME_NAME + 1)) {
1336 		ret = -EFAULT;
1337 		goto out_drop_write;
1338 	}
1339 
1340 	len = strnlen(label, NILFS_MAX_VOLUME_NAME + 1);
1341 	if (len > NILFS_MAX_VOLUME_NAME) {
1342 		nilfs_err(sb, "unable to set label with more than %zu bytes",
1343 			  NILFS_MAX_VOLUME_NAME);
1344 		ret = -EINVAL;
1345 		goto out_drop_write;
1346 	}
1347 
1348 	down_write(&nilfs->ns_sem);
1349 	sbp = nilfs_prepare_super(sb, false);
1350 	if (unlikely(!sbp)) {
1351 		ret = -EIO;
1352 		goto out_unlock;
1353 	}
1354 
1355 	strtomem_pad(sbp[0]->s_volume_name, label, 0);
1356 	if (sbp[1])
1357 		strtomem_pad(sbp[1]->s_volume_name, label, 0);
1358 
1359 	ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
1360 
1361 out_unlock:
1362 	up_write(&nilfs->ns_sem);
1363 out_drop_write:
1364 	mnt_drop_write_file(filp);
1365 	return ret;
1366 }
1367 
1368 long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1369 {
1370 	struct inode *inode = file_inode(filp);
1371 	void __user *argp = (void __user *)arg;
1372 
1373 	switch (cmd) {
1374 	case FS_IOC_GETVERSION:
1375 		return nilfs_ioctl_getversion(inode, argp);
1376 	case NILFS_IOCTL_CHANGE_CPMODE:
1377 		return nilfs_ioctl_change_cpmode(inode, filp, cmd, argp);
1378 	case NILFS_IOCTL_DELETE_CHECKPOINT:
1379 		return nilfs_ioctl_delete_checkpoint(inode, filp, cmd, argp);
1380 	case NILFS_IOCTL_GET_CPINFO:
1381 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
1382 					    sizeof(struct nilfs_cpinfo),
1383 					    nilfs_ioctl_do_get_cpinfo);
1384 	case NILFS_IOCTL_GET_CPSTAT:
1385 		return nilfs_ioctl_get_cpstat(inode, filp, cmd, argp);
1386 	case NILFS_IOCTL_GET_SUINFO:
1387 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
1388 					    sizeof(struct nilfs_suinfo),
1389 					    nilfs_ioctl_do_get_suinfo);
1390 	case NILFS_IOCTL_SET_SUINFO:
1391 		return nilfs_ioctl_set_suinfo(inode, filp, cmd, argp);
1392 	case NILFS_IOCTL_GET_SUSTAT:
1393 		return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
1394 	case NILFS_IOCTL_GET_VINFO:
1395 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
1396 					    sizeof(struct nilfs_vinfo),
1397 					    nilfs_ioctl_do_get_vinfo);
1398 	case NILFS_IOCTL_GET_BDESCS:
1399 		return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
1400 	case NILFS_IOCTL_CLEAN_SEGMENTS:
1401 		return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
1402 	case NILFS_IOCTL_SYNC:
1403 		return nilfs_ioctl_sync(inode, filp, cmd, argp);
1404 	case NILFS_IOCTL_RESIZE:
1405 		return nilfs_ioctl_resize(inode, filp, argp);
1406 	case NILFS_IOCTL_SET_ALLOC_RANGE:
1407 		return nilfs_ioctl_set_alloc_range(inode, argp);
1408 	case FITRIM:
1409 		return nilfs_ioctl_trim_fs(inode, argp);
1410 	case FS_IOC_GETFSLABEL:
1411 		return nilfs_ioctl_get_fslabel(inode->i_sb, argp);
1412 	case FS_IOC_SETFSLABEL:
1413 		return nilfs_ioctl_set_fslabel(inode->i_sb, filp, argp);
1414 	default:
1415 		return -ENOTTY;
1416 	}
1417 }
1418 
1419 #ifdef CONFIG_COMPAT
1420 long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1421 {
1422 	switch (cmd) {
1423 	case FS_IOC32_GETVERSION:
1424 		cmd = FS_IOC_GETVERSION;
1425 		break;
1426 	case NILFS_IOCTL_CHANGE_CPMODE:
1427 	case NILFS_IOCTL_DELETE_CHECKPOINT:
1428 	case NILFS_IOCTL_GET_CPINFO:
1429 	case NILFS_IOCTL_GET_CPSTAT:
1430 	case NILFS_IOCTL_GET_SUINFO:
1431 	case NILFS_IOCTL_SET_SUINFO:
1432 	case NILFS_IOCTL_GET_SUSTAT:
1433 	case NILFS_IOCTL_GET_VINFO:
1434 	case NILFS_IOCTL_GET_BDESCS:
1435 	case NILFS_IOCTL_CLEAN_SEGMENTS:
1436 	case NILFS_IOCTL_SYNC:
1437 	case NILFS_IOCTL_RESIZE:
1438 	case NILFS_IOCTL_SET_ALLOC_RANGE:
1439 	case FITRIM:
1440 	case FS_IOC_GETFSLABEL:
1441 	case FS_IOC_SETFSLABEL:
1442 		break;
1443 	default:
1444 		return -ENOIOCTLCMD;
1445 	}
1446 	return nilfs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1447 }
1448 #endif
1449