xref: /linux/fs/nilfs2/ioctl.c (revision be3e5d10643d3be1cbac9d9939f220a99253f980)
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.  If successful,
37  * the requested metadata information is copied to userspace memory.
38  *
39  * Return: 0 on success, or one of the following negative error codes on
40  * failure:
41  * * %-EFAULT	- Failure during execution of requested operation.
42  * * %-EINVAL	- Invalid arguments from userspace.
43  * * %-ENOMEM	- Insufficient memory available.
44  */
45 static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
46 				 struct nilfs_argv *argv, int dir,
47 				 ssize_t (*dofunc)(struct the_nilfs *,
48 						   __u64 *, int,
49 						   void *, size_t, size_t))
50 {
51 	void *buf;
52 	void __user *base = u64_to_user_ptr(argv->v_base);
53 	size_t maxmembs, total, n;
54 	ssize_t nr;
55 	int ret, i;
56 	__u64 pos, ppos;
57 
58 	if (argv->v_nmembs == 0)
59 		return 0;
60 
61 	if ((size_t)argv->v_size > PAGE_SIZE)
62 		return -EINVAL;
63 
64 	/*
65 	 * Reject pairs of a start item position (argv->v_index) and a
66 	 * total count (argv->v_nmembs) which leads position 'pos' to
67 	 * overflow by the increment at the end of the loop.
68 	 */
69 	if (argv->v_index > ~(__u64)0 - argv->v_nmembs)
70 		return -EINVAL;
71 
72 	buf = (void *)get_zeroed_page(GFP_NOFS);
73 	if (unlikely(!buf))
74 		return -ENOMEM;
75 	maxmembs = PAGE_SIZE / argv->v_size;
76 
77 	ret = 0;
78 	total = 0;
79 	pos = argv->v_index;
80 	for (i = 0; i < argv->v_nmembs; i += n) {
81 		n = (argv->v_nmembs - i < maxmembs) ?
82 			argv->v_nmembs - i : maxmembs;
83 		if ((dir & _IOC_WRITE) &&
84 		    copy_from_user(buf, base + argv->v_size * i,
85 				   argv->v_size * n)) {
86 			ret = -EFAULT;
87 			break;
88 		}
89 		ppos = pos;
90 		nr = dofunc(nilfs, &pos, argv->v_flags, buf, argv->v_size,
91 			       n);
92 		if (nr < 0) {
93 			ret = nr;
94 			break;
95 		}
96 		if ((dir & _IOC_READ) &&
97 		    copy_to_user(base + argv->v_size * i, buf,
98 				 argv->v_size * nr)) {
99 			ret = -EFAULT;
100 			break;
101 		}
102 		total += nr;
103 		if ((size_t)nr < n)
104 			break;
105 		if (pos == ppos)
106 			pos += n;
107 	}
108 	argv->v_nmembs = total;
109 
110 	free_pages((unsigned long)buf, 0);
111 	return ret;
112 }
113 
114 /**
115  * nilfs_fileattr_get - retrieve miscellaneous file attributes
116  * @dentry: the object to retrieve from
117  * @fa:     fileattr pointer
118  *
119  * Return: always 0 as success.
120  */
121 int nilfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
122 {
123 	struct inode *inode = d_inode(dentry);
124 
125 	fileattr_fill_flags(fa, NILFS_I(inode)->i_flags & FS_FL_USER_VISIBLE);
126 
127 	return 0;
128 }
129 
130 /**
131  * nilfs_fileattr_set - change miscellaneous file attributes
132  * @idmap:  idmap of the mount
133  * @dentry: the object to change
134  * @fa:     fileattr pointer
135  *
136  * Return: 0 on success, or a negative error code on failure.
137  */
138 int nilfs_fileattr_set(struct mnt_idmap *idmap,
139 		       struct dentry *dentry, struct file_kattr *fa)
140 {
141 	struct inode *inode = d_inode(dentry);
142 	struct nilfs_transaction_info ti;
143 	unsigned int flags, oldflags;
144 	int ret;
145 
146 	if (fileattr_has_fsx(fa))
147 		return -EOPNOTSUPP;
148 
149 	flags = nilfs_mask_flags(inode->i_mode, fa->flags);
150 
151 	ret = nilfs_transaction_begin(inode->i_sb, &ti, 0);
152 	if (ret)
153 		return ret;
154 
155 	oldflags = NILFS_I(inode)->i_flags & ~FS_FL_USER_MODIFIABLE;
156 	NILFS_I(inode)->i_flags = oldflags | (flags & FS_FL_USER_MODIFIABLE);
157 
158 	nilfs_set_inode_flags(inode);
159 	inode_set_ctime_current(inode);
160 	if (IS_SYNC(inode))
161 		nilfs_set_transaction_flag(NILFS_TI_SYNC);
162 
163 	nilfs_mark_inode_dirty(inode);
164 	return nilfs_transaction_commit(inode->i_sb);
165 }
166 
167 /**
168  * nilfs_ioctl_getversion - get info about a file's version (generation number)
169  * @inode: inode object
170  * @argp:  userspace memory where the generation number of @inode is stored
171  *
172  * Return: 0 on success, or %-EFAULT on error.
173  */
174 static int nilfs_ioctl_getversion(struct inode *inode, void __user *argp)
175 {
176 	return put_user(inode->i_generation, (int __user *)argp);
177 }
178 
179 /**
180  * nilfs_ioctl_change_cpmode - change checkpoint mode (checkpoint/snapshot)
181  * @inode: inode object
182  * @filp: file object
183  * @cmd: ioctl's request code
184  * @argp: pointer on argument from userspace
185  *
186  * Description: nilfs_ioctl_change_cpmode() function changes mode of
187  * given checkpoint between checkpoint and snapshot state. This ioctl
188  * is used in chcp and mkcp utilities.
189  *
190  * Return: 0 on success, or one of the following negative error codes on
191  * failure:
192  * %-EFAULT	- Failure during checkpoint mode changing.
193  * %-EPERM	- Operation not permitted.
194  */
195 static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
196 				     unsigned int cmd, void __user *argp)
197 {
198 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
199 	struct nilfs_transaction_info ti;
200 	struct nilfs_cpmode cpmode;
201 	int ret;
202 
203 	if (!capable(CAP_SYS_ADMIN))
204 		return -EPERM;
205 
206 	ret = mnt_want_write_file(filp);
207 	if (ret)
208 		return ret;
209 
210 	ret = -EFAULT;
211 	if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
212 		goto out;
213 
214 	mutex_lock(&nilfs->ns_snapshot_mount_mutex);
215 
216 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
217 	ret = nilfs_cpfile_change_cpmode(
218 		nilfs->ns_cpfile, cpmode.cm_cno, cpmode.cm_mode);
219 	if (unlikely(ret < 0))
220 		nilfs_transaction_abort(inode->i_sb);
221 	else
222 		nilfs_transaction_commit(inode->i_sb); /* never fails */
223 
224 	mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
225 out:
226 	mnt_drop_write_file(filp);
227 	return ret;
228 }
229 
230 /**
231  * nilfs_ioctl_delete_checkpoint - remove checkpoint
232  * @inode: inode object
233  * @filp: file object
234  * @cmd: ioctl's request code
235  * @argp: pointer on argument from userspace
236  *
237  * Description: nilfs_ioctl_delete_checkpoint() function removes
238  * checkpoint from NILFS2 file system. This ioctl is used in rmcp
239  * utility.
240  *
241  * Return: 0 on success, or one of the following negative error codes on
242  * failure:
243  * %-EFAULT	- Failure during checkpoint removing.
244  * %-EPERM	- Operation not permitted.
245  */
246 static int
247 nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
248 			      unsigned int cmd, void __user *argp)
249 {
250 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
251 	struct nilfs_transaction_info ti;
252 	__u64 cno;
253 	int ret;
254 
255 	if (!capable(CAP_SYS_ADMIN))
256 		return -EPERM;
257 
258 	ret = mnt_want_write_file(filp);
259 	if (ret)
260 		return ret;
261 
262 	ret = -EFAULT;
263 	if (copy_from_user(&cno, argp, sizeof(cno)))
264 		goto out;
265 
266 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
267 	ret = nilfs_cpfile_delete_checkpoint(nilfs->ns_cpfile, cno);
268 	if (unlikely(ret < 0))
269 		nilfs_transaction_abort(inode->i_sb);
270 	else
271 		nilfs_transaction_commit(inode->i_sb); /* never fails */
272 out:
273 	mnt_drop_write_file(filp);
274 	return ret;
275 }
276 
277 /**
278  * nilfs_ioctl_do_get_cpinfo - callback method getting info about checkpoints
279  * @nilfs: nilfs object
280  * @posp: pointer on array of checkpoint's numbers
281  * @flags: checkpoint mode (checkpoint or snapshot)
282  * @buf: buffer for storing checkponts' info
283  * @size: size in bytes of one checkpoint info item in array
284  * @nmembs: number of checkpoints in array (numbers and infos)
285  *
286  * Description: nilfs_ioctl_do_get_cpinfo() function returns info about
287  * requested checkpoints. The NILFS_IOCTL_GET_CPINFO ioctl is used in
288  * lscp utility and by nilfs_cleanerd daemon.
289  *
290  * Return: Count of nilfs_cpinfo structures in output buffer.
291  */
292 static ssize_t
293 nilfs_ioctl_do_get_cpinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
294 			  void *buf, size_t size, size_t nmembs)
295 {
296 	int ret;
297 
298 	down_read(&nilfs->ns_segctor_sem);
299 	ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
300 				      size, nmembs);
301 	up_read(&nilfs->ns_segctor_sem);
302 	return ret;
303 }
304 
305 /**
306  * nilfs_ioctl_get_cpstat - get checkpoints statistics
307  * @inode: inode object
308  * @filp: file object
309  * @cmd: ioctl's request code
310  * @argp: pointer on argument from userspace
311  *
312  * Description: nilfs_ioctl_get_cpstat() returns information about checkpoints.
313  * The NILFS_IOCTL_GET_CPSTAT ioctl is used by lscp, rmcp utilities
314  * and by nilfs_cleanerd daemon.  The checkpoint statistics are copied to
315  * the userspace memory pointed to by @argp.
316  *
317  * Return: 0 on success, or one of the following negative error codes on
318  * failure:
319  * * %-EFAULT	- Failure during getting checkpoints statistics.
320  * * %-EIO	- I/O error.
321  * * %-ENOMEM	- Insufficient memory available.
322  */
323 static int nilfs_ioctl_get_cpstat(struct inode *inode, struct file *filp,
324 				  unsigned int cmd, void __user *argp)
325 {
326 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
327 	struct nilfs_cpstat cpstat;
328 	int ret;
329 
330 	down_read(&nilfs->ns_segctor_sem);
331 	ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
332 	up_read(&nilfs->ns_segctor_sem);
333 	if (ret < 0)
334 		return ret;
335 
336 	if (copy_to_user(argp, &cpstat, sizeof(cpstat)))
337 		ret = -EFAULT;
338 	return ret;
339 }
340 
341 /**
342  * nilfs_ioctl_do_get_suinfo - callback method getting segment usage info
343  * @nilfs: nilfs object
344  * @posp: pointer on array of segment numbers
345  * @flags: *not used*
346  * @buf: buffer for storing suinfo array
347  * @size: size in bytes of one suinfo item in array
348  * @nmembs: count of segment numbers and suinfos in array
349  *
350  * Description: nilfs_ioctl_do_get_suinfo() function returns segment usage
351  * info about requested segments. The NILFS_IOCTL_GET_SUINFO ioctl is used
352  * in lssu, nilfs_resize utilities and by nilfs_cleanerd daemon.
353  *
354  * Return: Count of nilfs_suinfo structures in output buffer on success,
355  * or a negative error code on failure.
356  */
357 static ssize_t
358 nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
359 			  void *buf, size_t size, size_t nmembs)
360 {
361 	int ret;
362 
363 	down_read(&nilfs->ns_segctor_sem);
364 	ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
365 				      nmembs);
366 	up_read(&nilfs->ns_segctor_sem);
367 	return ret;
368 }
369 
370 /**
371  * nilfs_ioctl_get_sustat - get segment usage statistics
372  * @inode: inode object
373  * @filp: file object
374  * @cmd: ioctl's request code
375  * @argp: pointer on argument from userspace
376  *
377  * Description: nilfs_ioctl_get_sustat() returns segment usage statistics.
378  * The NILFS_IOCTL_GET_SUSTAT ioctl is used in lssu, nilfs_resize utilities
379  * and by nilfs_cleanerd daemon.  The requested segment usage information is
380  * copied to the userspace memory pointed to by @argp.
381  *
382  * Return: 0 on success, or one of the following negative error codes on
383  * failure:
384  * * %-EFAULT	- Failure during getting segment usage statistics.
385  * * %-EIO	- I/O error.
386  * * %-ENOMEM	- Insufficient memory available.
387  */
388 static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
389 				  unsigned int cmd, void __user *argp)
390 {
391 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
392 	struct nilfs_sustat sustat;
393 	int ret;
394 
395 	down_read(&nilfs->ns_segctor_sem);
396 	ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
397 	up_read(&nilfs->ns_segctor_sem);
398 	if (ret < 0)
399 		return ret;
400 
401 	if (copy_to_user(argp, &sustat, sizeof(sustat)))
402 		ret = -EFAULT;
403 	return ret;
404 }
405 
406 /**
407  * nilfs_ioctl_do_get_vinfo - callback method getting virtual blocks info
408  * @nilfs: nilfs object
409  * @posp: *not used*
410  * @flags: *not used*
411  * @buf: buffer for storing array of nilfs_vinfo structures
412  * @size: size in bytes of one vinfo item in array
413  * @nmembs: count of vinfos in array
414  *
415  * Description: nilfs_ioctl_do_get_vinfo() function returns information
416  * on virtual block addresses. The NILFS_IOCTL_GET_VINFO ioctl is used
417  * by nilfs_cleanerd daemon.
418  *
419  * Return: Count of nilfs_vinfo structures in output buffer on success, or
420  * a negative error code on failure.
421  */
422 static ssize_t
423 nilfs_ioctl_do_get_vinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
424 			 void *buf, size_t size, size_t nmembs)
425 {
426 	int ret;
427 
428 	down_read(&nilfs->ns_segctor_sem);
429 	ret = nilfs_dat_get_vinfo(nilfs->ns_dat, buf, size, nmembs);
430 	up_read(&nilfs->ns_segctor_sem);
431 	return ret;
432 }
433 
434 /**
435  * nilfs_ioctl_do_get_bdescs - callback method getting disk block descriptors
436  * @nilfs: nilfs object
437  * @posp: *not used*
438  * @flags: *not used*
439  * @buf: buffer for storing array of nilfs_bdesc structures
440  * @size: size in bytes of one bdesc item in array
441  * @nmembs: count of bdescs in array
442  *
443  * Description: nilfs_ioctl_do_get_bdescs() function returns information
444  * about descriptors of disk block numbers. The NILFS_IOCTL_GET_BDESCS ioctl
445  * is used by nilfs_cleanerd daemon.
446  *
447  * Return: Count of nilfs_bdescs structures in output buffer on success, or
448  * a negative error code on failure.
449  */
450 static ssize_t
451 nilfs_ioctl_do_get_bdescs(struct the_nilfs *nilfs, __u64 *posp, int flags,
452 			  void *buf, size_t size, size_t nmembs)
453 {
454 	struct nilfs_bmap *bmap = NILFS_I(nilfs->ns_dat)->i_bmap;
455 	struct nilfs_bdesc *bdescs = buf;
456 	int ret, i;
457 
458 	down_read(&nilfs->ns_segctor_sem);
459 	for (i = 0; i < nmembs; i++) {
460 		ret = nilfs_bmap_lookup_at_level(bmap,
461 						 bdescs[i].bd_offset,
462 						 bdescs[i].bd_level + 1,
463 						 &bdescs[i].bd_blocknr);
464 		if (ret < 0) {
465 			if (ret != -ENOENT) {
466 				up_read(&nilfs->ns_segctor_sem);
467 				return ret;
468 			}
469 			bdescs[i].bd_blocknr = 0;
470 		}
471 	}
472 	up_read(&nilfs->ns_segctor_sem);
473 	return nmembs;
474 }
475 
476 /**
477  * nilfs_ioctl_get_bdescs - get disk block descriptors
478  * @inode: inode object
479  * @filp: file object
480  * @cmd: ioctl's request code
481  * @argp: pointer on argument from userspace
482  *
483  * Description: nilfs_ioctl_do_get_bdescs() function returns information
484  * about descriptors of disk block numbers. The NILFS_IOCTL_GET_BDESCS ioctl
485  * is used by nilfs_cleanerd daemon.  If successful, disk block descriptors
486  * are copied to userspace pointer @argp.
487  *
488  * Return: 0 on success, or one of the following negative error codes on
489  * failure:
490  * * %-EFAULT	- Failure during getting disk block descriptors.
491  * * %-EINVAL	- Invalid arguments from userspace.
492  * * %-EIO	- I/O error.
493  * * %-ENOMEM	- Insufficient memory available.
494  */
495 static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp,
496 				  unsigned int cmd, void __user *argp)
497 {
498 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
499 	struct nilfs_argv argv;
500 	int ret;
501 
502 	if (copy_from_user(&argv, argp, sizeof(argv)))
503 		return -EFAULT;
504 
505 	if (argv.v_size != sizeof(struct nilfs_bdesc))
506 		return -EINVAL;
507 
508 	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
509 				    nilfs_ioctl_do_get_bdescs);
510 	if (ret < 0)
511 		return ret;
512 
513 	if (copy_to_user(argp, &argv, sizeof(argv)))
514 		ret = -EFAULT;
515 	return ret;
516 }
517 
518 /**
519  * nilfs_ioctl_move_inode_block - prepare data/node block for moving by GC
520  * @inode: inode object
521  * @vdesc: descriptor of virtual block number
522  * @buffers: list of moving buffers
523  *
524  * Description: nilfs_ioctl_move_inode_block() function registers data/node
525  * buffer in the GC pagecache and submit read request.
526  *
527  * Return: 0 on success, or one of the following negative error codes on
528  * failure:
529  * * %-EEXIST	- Block conflict detected.
530  * * %-EIO	- I/O error.
531  * * %-ENOENT	- Requested block doesn't exist.
532  * * %-ENOMEM	- Insufficient memory available.
533  */
534 static int nilfs_ioctl_move_inode_block(struct inode *inode,
535 					struct nilfs_vdesc *vdesc,
536 					struct list_head *buffers)
537 {
538 	struct buffer_head *bh;
539 	int ret;
540 
541 	if (vdesc->vd_flags == 0)
542 		ret = nilfs_gccache_submit_read_data(
543 			inode, vdesc->vd_offset, vdesc->vd_blocknr,
544 			vdesc->vd_vblocknr, &bh);
545 	else
546 		ret = nilfs_gccache_submit_read_node(
547 			inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh);
548 
549 	if (unlikely(ret < 0)) {
550 		if (ret == -ENOENT)
551 			nilfs_crit(inode->i_sb,
552 				   "%s: invalid virtual block address (%s): ino=%llu, cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu",
553 				   __func__, vdesc->vd_flags ? "node" : "data",
554 				   (unsigned long long)vdesc->vd_ino,
555 				   (unsigned long long)vdesc->vd_cno,
556 				   (unsigned long long)vdesc->vd_offset,
557 				   (unsigned long long)vdesc->vd_blocknr,
558 				   (unsigned long long)vdesc->vd_vblocknr);
559 		return ret;
560 	}
561 	if (unlikely(!list_empty(&bh->b_assoc_buffers))) {
562 		nilfs_crit(inode->i_sb,
563 			   "%s: conflicting %s buffer: ino=%llu, cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu",
564 			   __func__, vdesc->vd_flags ? "node" : "data",
565 			   (unsigned long long)vdesc->vd_ino,
566 			   (unsigned long long)vdesc->vd_cno,
567 			   (unsigned long long)vdesc->vd_offset,
568 			   (unsigned long long)vdesc->vd_blocknr,
569 			   (unsigned long long)vdesc->vd_vblocknr);
570 		brelse(bh);
571 		return -EEXIST;
572 	}
573 	list_add_tail(&bh->b_assoc_buffers, buffers);
574 	return 0;
575 }
576 
577 /**
578  * nilfs_ioctl_move_blocks - move valid inode's blocks during garbage collection
579  * @sb: superblock object
580  * @argv: vector of arguments from userspace
581  * @buf: array of nilfs_vdesc structures
582  *
583  * Description: nilfs_ioctl_move_blocks() function reads valid data/node
584  * blocks that garbage collector specified with the array of nilfs_vdesc
585  * structures and stores them into page caches of GC inodes.
586  *
587  * Return: Number of processed nilfs_vdesc structures on success, or
588  * a negative error code on failure.
589  */
590 static int nilfs_ioctl_move_blocks(struct super_block *sb,
591 				   struct nilfs_argv *argv, void *buf)
592 {
593 	size_t nmembs = argv->v_nmembs;
594 	struct the_nilfs *nilfs = sb->s_fs_info;
595 	struct inode *inode;
596 	struct nilfs_vdesc *vdesc;
597 	struct buffer_head *bh, *n;
598 	LIST_HEAD(buffers);
599 	ino_t ino;
600 	__u64 cno;
601 	int i, ret;
602 
603 	for (i = 0, vdesc = buf; i < nmembs; ) {
604 		ino = vdesc->vd_ino;
605 		cno = vdesc->vd_cno;
606 		inode = nilfs_iget_for_gc(sb, ino, cno);
607 		if (IS_ERR(inode)) {
608 			ret = PTR_ERR(inode);
609 			goto failed;
610 		}
611 		if (list_empty(&NILFS_I(inode)->i_dirty)) {
612 			/*
613 			 * Add the inode to GC inode list. Garbage Collection
614 			 * is serialized and no two processes manipulate the
615 			 * list simultaneously.
616 			 */
617 			igrab(inode);
618 			list_add(&NILFS_I(inode)->i_dirty,
619 				 &nilfs->ns_gc_inodes);
620 		}
621 
622 		do {
623 			ret = nilfs_ioctl_move_inode_block(inode, vdesc,
624 							   &buffers);
625 			if (unlikely(ret < 0)) {
626 				iput(inode);
627 				goto failed;
628 			}
629 			vdesc++;
630 		} while (++i < nmembs &&
631 			 vdesc->vd_ino == ino && vdesc->vd_cno == cno);
632 
633 		iput(inode); /* The inode still remains in GC inode list */
634 	}
635 
636 	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
637 		ret = nilfs_gccache_wait_and_mark_dirty(bh);
638 		if (unlikely(ret < 0)) {
639 			WARN_ON(ret == -EEXIST);
640 			goto failed;
641 		}
642 		list_del_init(&bh->b_assoc_buffers);
643 		brelse(bh);
644 	}
645 	return nmembs;
646 
647  failed:
648 	list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
649 		list_del_init(&bh->b_assoc_buffers);
650 		brelse(bh);
651 	}
652 	return ret;
653 }
654 
655 /**
656  * nilfs_ioctl_delete_checkpoints - delete checkpoints
657  * @nilfs: nilfs object
658  * @argv: vector of arguments from userspace
659  * @buf: array of periods of checkpoints numbers
660  *
661  * Description: nilfs_ioctl_delete_checkpoints() function deletes checkpoints
662  * in the period from p_start to p_end, excluding p_end itself. The checkpoints
663  * which have been already deleted are ignored.
664  *
665  * Return: Number of processed nilfs_period structures on success, or one of
666  * the following negative error codes on failure:
667  * * %-EINVAL	- invalid checkpoints.
668  * * %-EIO	- I/O error.
669  * * %-ENOMEM	- Insufficient memory available.
670  */
671 static int nilfs_ioctl_delete_checkpoints(struct the_nilfs *nilfs,
672 					  struct nilfs_argv *argv, void *buf)
673 {
674 	size_t nmembs = argv->v_nmembs;
675 	struct inode *cpfile = nilfs->ns_cpfile;
676 	struct nilfs_period *periods = buf;
677 	int ret, i;
678 
679 	for (i = 0; i < nmembs; i++) {
680 		ret = nilfs_cpfile_delete_checkpoints(
681 			cpfile, periods[i].p_start, periods[i].p_end);
682 		if (ret < 0)
683 			return ret;
684 	}
685 	return nmembs;
686 }
687 
688 /**
689  * nilfs_ioctl_free_vblocknrs - free virtual block numbers
690  * @nilfs: nilfs object
691  * @argv: vector of arguments from userspace
692  * @buf: array of virtual block numbers
693  *
694  * Description: nilfs_ioctl_free_vblocknrs() function frees
695  * the virtual block numbers specified by @buf and @argv->v_nmembs.
696  *
697  * Return: Number of processed virtual block numbers on success, or one of the
698  * following negative error codes on failure:
699  * * %-EIO	- I/O error.
700  * * %-ENOENT	- Unallocated virtual block number.
701  * * %-ENOMEM	- Insufficient memory available.
702  */
703 static int nilfs_ioctl_free_vblocknrs(struct the_nilfs *nilfs,
704 				      struct nilfs_argv *argv, void *buf)
705 {
706 	size_t nmembs = argv->v_nmembs;
707 	int ret;
708 
709 	ret = nilfs_dat_freev(nilfs->ns_dat, buf, nmembs);
710 
711 	return (ret < 0) ? ret : nmembs;
712 }
713 
714 /**
715  * nilfs_ioctl_mark_blocks_dirty - mark blocks dirty
716  * @nilfs: nilfs object
717  * @argv: vector of arguments from userspace
718  * @buf: array of block descriptors
719  *
720  * Description: nilfs_ioctl_mark_blocks_dirty() function marks
721  * metadata file or data blocks as dirty.
722  *
723  * Return: Number of processed block descriptors on success, or one of the
724  * following negative error codes on failure:
725  * * %-EIO	- I/O error.
726  * * %-ENOENT	- Non-existent block (hole block).
727  * * %-ENOMEM	- Insufficient memory available.
728  */
729 static int nilfs_ioctl_mark_blocks_dirty(struct the_nilfs *nilfs,
730 					 struct nilfs_argv *argv, void *buf)
731 {
732 	size_t nmembs = argv->v_nmembs;
733 	struct nilfs_bmap *bmap = NILFS_I(nilfs->ns_dat)->i_bmap;
734 	struct nilfs_bdesc *bdescs = buf;
735 	struct buffer_head *bh;
736 	int ret, i;
737 
738 	for (i = 0; i < nmembs; i++) {
739 		/*
740 		 * bd_oblocknr must never be 0 as block 0
741 		 * is never a valid GC target block
742 		 */
743 		if (unlikely(!bdescs[i].bd_oblocknr))
744 			return -EINVAL;
745 		/* XXX: use macro or inline func to check liveness */
746 		ret = nilfs_bmap_lookup_at_level(bmap,
747 						 bdescs[i].bd_offset,
748 						 bdescs[i].bd_level + 1,
749 						 &bdescs[i].bd_blocknr);
750 		if (ret < 0) {
751 			if (ret != -ENOENT)
752 				return ret;
753 			bdescs[i].bd_blocknr = 0;
754 		}
755 		if (bdescs[i].bd_blocknr != bdescs[i].bd_oblocknr)
756 			/* skip dead block */
757 			continue;
758 		if (bdescs[i].bd_level == 0) {
759 			ret = nilfs_mdt_get_block(nilfs->ns_dat,
760 						  bdescs[i].bd_offset,
761 						  false, NULL, &bh);
762 			if (unlikely(ret)) {
763 				WARN_ON(ret == -ENOENT);
764 				return ret;
765 			}
766 			mark_buffer_dirty(bh);
767 			nilfs_mdt_mark_dirty(nilfs->ns_dat);
768 			put_bh(bh);
769 		} else {
770 			ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
771 					      bdescs[i].bd_level);
772 			if (ret < 0) {
773 				WARN_ON(ret == -ENOENT);
774 				return ret;
775 			}
776 		}
777 	}
778 	return nmembs;
779 }
780 
781 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
782 				       struct nilfs_argv *argv, void **kbufs)
783 {
784 	const char *msg;
785 	int ret;
786 
787 	ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], kbufs[1]);
788 	if (ret < 0) {
789 		/*
790 		 * can safely abort because checkpoints can be removed
791 		 * independently.
792 		 */
793 		msg = "cannot delete checkpoints";
794 		goto failed;
795 	}
796 	ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], kbufs[2]);
797 	if (ret < 0) {
798 		/*
799 		 * can safely abort because DAT file is updated atomically
800 		 * using a copy-on-write technique.
801 		 */
802 		msg = "cannot delete virtual blocks from DAT file";
803 		goto failed;
804 	}
805 	ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], kbufs[3]);
806 	if (ret < 0) {
807 		/*
808 		 * can safely abort because the operation is nondestructive.
809 		 */
810 		msg = "cannot mark copying blocks dirty";
811 		goto failed;
812 	}
813 	return 0;
814 
815  failed:
816 	nilfs_err(nilfs->ns_sb, "error %d preparing GC: %s", ret, msg);
817 	return ret;
818 }
819 
820 /**
821  * nilfs_ioctl_clean_segments - clean segments
822  * @inode: inode object
823  * @filp: file object
824  * @cmd: ioctl's request code
825  * @argp: pointer on argument from userspace
826  *
827  * Description: nilfs_ioctl_clean_segments() function makes garbage
828  * collection operation in the environment of requested parameters
829  * from userspace. The NILFS_IOCTL_CLEAN_SEGMENTS ioctl is used by
830  * nilfs_cleanerd daemon.
831  *
832  * Return: 0 on success, or a negative error code on failure.
833  */
834 static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
835 				      unsigned int cmd, void __user *argp)
836 {
837 	struct nilfs_argv argv[5];
838 	static const size_t argsz[5] = {
839 		sizeof(struct nilfs_vdesc),
840 		sizeof(struct nilfs_period),
841 		sizeof(__u64),
842 		sizeof(struct nilfs_bdesc),
843 		sizeof(__u64),
844 	};
845 	void *kbufs[5];
846 	struct the_nilfs *nilfs;
847 	size_t len, nsegs;
848 	int n, ret;
849 
850 	if (!capable(CAP_SYS_ADMIN))
851 		return -EPERM;
852 
853 	ret = mnt_want_write_file(filp);
854 	if (ret)
855 		return ret;
856 
857 	ret = -EFAULT;
858 	if (copy_from_user(argv, argp, sizeof(argv)))
859 		goto out;
860 
861 	ret = -EINVAL;
862 	nsegs = argv[4].v_nmembs;
863 	if (argv[4].v_size != argsz[4])
864 		goto out;
865 
866 	/*
867 	 * argv[4] points to segment numbers this ioctl cleans.  We
868 	 * use kmalloc() for its buffer because the memory used for the
869 	 * segment numbers is small enough.
870 	 */
871 	kbufs[4] = memdup_array_user(u64_to_user_ptr(argv[4].v_base),
872 				     nsegs, sizeof(__u64));
873 	if (IS_ERR(kbufs[4])) {
874 		ret = PTR_ERR(kbufs[4]);
875 		goto out;
876 	}
877 	nilfs = inode->i_sb->s_fs_info;
878 
879 	for (n = 0; n < 4; n++) {
880 		ret = -EINVAL;
881 		if (argv[n].v_size != argsz[n])
882 			goto out_free;
883 
884 		if (argv[n].v_nmembs > nsegs * nilfs->ns_blocks_per_segment)
885 			goto out_free;
886 
887 		if (argv[n].v_nmembs >= UINT_MAX / argv[n].v_size)
888 			goto out_free;
889 
890 		len = argv[n].v_size * argv[n].v_nmembs;
891 		if (len == 0) {
892 			kbufs[n] = NULL;
893 			continue;
894 		}
895 
896 		kbufs[n] = vmemdup_user(u64_to_user_ptr(argv[n].v_base), len);
897 		if (IS_ERR(kbufs[n])) {
898 			ret = PTR_ERR(kbufs[n]);
899 			goto out_free;
900 		}
901 	}
902 
903 	/*
904 	 * nilfs_ioctl_move_blocks() will call nilfs_iget_for_gc(),
905 	 * which will operates an inode list without blocking.
906 	 * To protect the list from concurrent operations,
907 	 * nilfs_ioctl_move_blocks should be atomic operation.
908 	 */
909 	if (test_and_set_bit(THE_NILFS_GC_RUNNING, &nilfs->ns_flags)) {
910 		ret = -EBUSY;
911 		goto out_free;
912 	}
913 
914 	ret = nilfs_ioctl_move_blocks(inode->i_sb, &argv[0], kbufs[0]);
915 	if (ret < 0) {
916 		nilfs_err(inode->i_sb,
917 			  "error %d preparing GC: cannot read source blocks",
918 			  ret);
919 	} else {
920 		if (nilfs_sb_need_update(nilfs))
921 			set_nilfs_discontinued(nilfs);
922 		ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
923 	}
924 
925 	nilfs_remove_all_gcinodes(nilfs);
926 	clear_nilfs_gc_running(nilfs);
927 
928 out_free:
929 	while (--n >= 0)
930 		kvfree(kbufs[n]);
931 	kfree(kbufs[4]);
932 out:
933 	mnt_drop_write_file(filp);
934 	return ret;
935 }
936 
937 /**
938  * nilfs_ioctl_sync - make a checkpoint
939  * @inode: inode object
940  * @filp: file object
941  * @cmd: ioctl's request code
942  * @argp: pointer on argument from userspace
943  *
944  * Description: nilfs_ioctl_sync() function constructs a logical segment
945  * for checkpointing.  This function guarantees that all modified data
946  * and metadata are written out to the device when it successfully
947  * returned.
948  *
949  * Return: 0 on success, or one of the following negative error codes on
950  * failure:
951  * * %-EFAULT		- Failure during execution of requested operation.
952  * * %-EIO		- I/O error.
953  * * %-ENOMEM		- Insufficient memory available.
954  * * %-ENOSPC		- No space left on device (only in a panic state).
955  * * %-ERESTARTSYS	- Interrupted.
956  * * %-EROFS		- Read only filesystem.
957  */
958 static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
959 			    unsigned int cmd, void __user *argp)
960 {
961 	__u64 cno;
962 	int ret;
963 	struct the_nilfs *nilfs;
964 
965 	ret = nilfs_construct_segment(inode->i_sb);
966 	if (ret < 0)
967 		return ret;
968 
969 	nilfs = inode->i_sb->s_fs_info;
970 	ret = nilfs_flush_device(nilfs);
971 	if (ret < 0)
972 		return ret;
973 
974 	if (argp != NULL) {
975 		down_read(&nilfs->ns_segctor_sem);
976 		cno = nilfs->ns_cno - 1;
977 		up_read(&nilfs->ns_segctor_sem);
978 		if (copy_to_user(argp, &cno, sizeof(cno)))
979 			return -EFAULT;
980 	}
981 	return 0;
982 }
983 
984 /**
985  * nilfs_ioctl_resize - resize NILFS2 volume
986  * @inode: inode object
987  * @filp: file object
988  * @argp: pointer on argument from userspace
989  *
990  * Return: 0 on success, or a negative error code on failure.
991  */
992 static int nilfs_ioctl_resize(struct inode *inode, struct file *filp,
993 			      void __user *argp)
994 {
995 	__u64 newsize;
996 	int ret = -EPERM;
997 
998 	if (!capable(CAP_SYS_ADMIN))
999 		goto out;
1000 
1001 	ret = mnt_want_write_file(filp);
1002 	if (ret)
1003 		goto out;
1004 
1005 	ret = -EFAULT;
1006 	if (copy_from_user(&newsize, argp, sizeof(newsize)))
1007 		goto out_drop_write;
1008 
1009 	ret = nilfs_resize_fs(inode->i_sb, newsize);
1010 
1011 out_drop_write:
1012 	mnt_drop_write_file(filp);
1013 out:
1014 	return ret;
1015 }
1016 
1017 /**
1018  * nilfs_ioctl_trim_fs() - trim ioctl handle function
1019  * @inode: inode object
1020  * @argp: pointer on argument from userspace
1021  *
1022  * Description: nilfs_ioctl_trim_fs is the FITRIM ioctl handle function. It
1023  * checks the arguments from userspace and calls nilfs_sufile_trim_fs, which
1024  * performs the actual trim operation.
1025  *
1026  * Return: 0 on success, or a negative error code on failure.
1027  */
1028 static int nilfs_ioctl_trim_fs(struct inode *inode, void __user *argp)
1029 {
1030 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1031 	struct fstrim_range range;
1032 	int ret;
1033 
1034 	if (!capable(CAP_SYS_ADMIN))
1035 		return -EPERM;
1036 
1037 	if (!bdev_max_discard_sectors(nilfs->ns_bdev))
1038 		return -EOPNOTSUPP;
1039 
1040 	if (copy_from_user(&range, argp, sizeof(range)))
1041 		return -EFAULT;
1042 
1043 	range.minlen = max_t(u64, range.minlen,
1044 			     bdev_discard_granularity(nilfs->ns_bdev));
1045 
1046 	down_read(&nilfs->ns_segctor_sem);
1047 	ret = nilfs_sufile_trim_fs(nilfs->ns_sufile, &range);
1048 	up_read(&nilfs->ns_segctor_sem);
1049 
1050 	if (ret < 0)
1051 		return ret;
1052 
1053 	if (copy_to_user(argp, &range, sizeof(range)))
1054 		return -EFAULT;
1055 
1056 	return 0;
1057 }
1058 
1059 /**
1060  * nilfs_ioctl_set_alloc_range - limit range of segments to be allocated
1061  * @inode: inode object
1062  * @argp: pointer on argument from userspace
1063  *
1064  * Description: nilfs_ioctl_set_alloc_range() function defines lower limit
1065  * of segments in bytes and upper limit of segments in bytes.
1066  * The NILFS_IOCTL_SET_ALLOC_RANGE is used by nilfs_resize utility.
1067  *
1068  * Return: 0 on success, or a negative error code on failure.
1069  */
1070 static int nilfs_ioctl_set_alloc_range(struct inode *inode, void __user *argp)
1071 {
1072 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1073 	__u64 range[2];
1074 	__u64 minseg, maxseg;
1075 	unsigned long segbytes;
1076 	int ret = -EPERM;
1077 
1078 	if (!capable(CAP_SYS_ADMIN))
1079 		goto out;
1080 
1081 	ret = -EFAULT;
1082 	if (copy_from_user(range, argp, sizeof(__u64[2])))
1083 		goto out;
1084 
1085 	ret = -ERANGE;
1086 	if (range[1] > bdev_nr_bytes(inode->i_sb->s_bdev))
1087 		goto out;
1088 
1089 	segbytes = nilfs->ns_blocks_per_segment * nilfs->ns_blocksize;
1090 
1091 	minseg = range[0] + segbytes - 1;
1092 	minseg = div64_ul(minseg, segbytes);
1093 
1094 	if (range[1] < 4096)
1095 		goto out;
1096 
1097 	maxseg = NILFS_SB2_OFFSET_BYTES(range[1]);
1098 	if (maxseg < segbytes)
1099 		goto out;
1100 
1101 	maxseg = div64_ul(maxseg, segbytes);
1102 	maxseg--;
1103 
1104 	ret = nilfs_sufile_set_alloc_range(nilfs->ns_sufile, minseg, maxseg);
1105 out:
1106 	return ret;
1107 }
1108 
1109 /**
1110  * nilfs_ioctl_get_info - wrapping function of get metadata info
1111  * @inode: inode object
1112  * @filp: file object
1113  * @cmd: ioctl's request code
1114  * @argp: pointer on argument from userspace
1115  * @membsz: size of an item in bytes
1116  * @dofunc: concrete function of getting metadata info
1117  *
1118  * Description: nilfs_ioctl_get_info() gets metadata info by means of
1119  * calling dofunc() function.  The requested metadata information is copied
1120  * to userspace memory @argp.
1121  *
1122  * Return: 0 on success, or one of the following negative error codes on
1123  * failure:
1124  * * %-EFAULT	- Failure during execution of requested operation.
1125  * * %-EINVAL	- Invalid arguments from userspace.
1126  * * %-EIO	- I/O error.
1127  * * %-ENOMEM	- Insufficient memory available.
1128  */
1129 static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
1130 				unsigned int cmd, void __user *argp,
1131 				size_t membsz,
1132 				ssize_t (*dofunc)(struct the_nilfs *,
1133 						  __u64 *, int,
1134 						  void *, size_t, size_t))
1135 
1136 {
1137 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1138 	struct nilfs_argv argv;
1139 	int ret;
1140 
1141 	if (copy_from_user(&argv, argp, sizeof(argv)))
1142 		return -EFAULT;
1143 
1144 	if (argv.v_size < membsz)
1145 		return -EINVAL;
1146 
1147 	ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
1148 	if (ret < 0)
1149 		return ret;
1150 
1151 	if (copy_to_user(argp, &argv, sizeof(argv)))
1152 		ret = -EFAULT;
1153 	return ret;
1154 }
1155 
1156 /**
1157  * nilfs_ioctl_set_suinfo - set segment usage info
1158  * @inode: inode object
1159  * @filp: file object
1160  * @cmd: ioctl's request code
1161  * @argp: pointer on argument from userspace
1162  *
1163  * Description: Expects an array of nilfs_suinfo_update structures
1164  * encapsulated in nilfs_argv and updates the segment usage info
1165  * according to the flags in nilfs_suinfo_update.
1166  *
1167  * Return: 0 on success, or one of the following negative error codes on
1168  * failure:
1169  * * %-EEXIST	- Block conflict detected.
1170  * * %-EFAULT	- Error copying input data.
1171  * * %-EINVAL	- Invalid values in input (segment number, flags or nblocks).
1172  * * %-EIO	- I/O error.
1173  * * %-ENOMEM	- Insufficient memory available.
1174  * * %-EPERM	- Not enough permissions.
1175  */
1176 static int nilfs_ioctl_set_suinfo(struct inode *inode, struct file *filp,
1177 				unsigned int cmd, void __user *argp)
1178 {
1179 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1180 	struct nilfs_transaction_info ti;
1181 	struct nilfs_argv argv;
1182 	size_t len;
1183 	void *kbuf;
1184 	int ret;
1185 
1186 	if (!capable(CAP_SYS_ADMIN))
1187 		return -EPERM;
1188 
1189 	ret = mnt_want_write_file(filp);
1190 	if (ret)
1191 		return ret;
1192 
1193 	ret = -EFAULT;
1194 	if (copy_from_user(&argv, argp, sizeof(argv)))
1195 		goto out;
1196 
1197 	ret = -EINVAL;
1198 	if (argv.v_size < sizeof(struct nilfs_suinfo_update))
1199 		goto out;
1200 
1201 	if (argv.v_nmembs > nilfs->ns_nsegments)
1202 		goto out;
1203 
1204 	if (argv.v_nmembs >= UINT_MAX / argv.v_size)
1205 		goto out;
1206 
1207 	len = argv.v_size * argv.v_nmembs;
1208 	if (!len) {
1209 		ret = 0;
1210 		goto out;
1211 	}
1212 
1213 	kbuf = vmemdup_user(u64_to_user_ptr(argv.v_base), len);
1214 	if (IS_ERR(kbuf)) {
1215 		ret = PTR_ERR(kbuf);
1216 		goto out;
1217 	}
1218 
1219 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
1220 	ret = nilfs_sufile_set_suinfo(nilfs->ns_sufile, kbuf, argv.v_size,
1221 			argv.v_nmembs);
1222 	if (unlikely(ret < 0))
1223 		nilfs_transaction_abort(inode->i_sb);
1224 	else
1225 		nilfs_transaction_commit(inode->i_sb); /* never fails */
1226 
1227 	kvfree(kbuf);
1228 out:
1229 	mnt_drop_write_file(filp);
1230 	return ret;
1231 }
1232 
1233 /**
1234  * nilfs_ioctl_get_fslabel - get the volume name of the file system
1235  * @sb:   super block instance
1236  * @argp: pointer to userspace memory where the volume name should be stored
1237  *
1238  * Return: 0 on success, %-EFAULT if copying to userspace memory fails.
1239  */
1240 static int nilfs_ioctl_get_fslabel(struct super_block *sb, void __user *argp)
1241 {
1242 	struct the_nilfs *nilfs = sb->s_fs_info;
1243 	char label[NILFS_MAX_VOLUME_NAME + 1];
1244 
1245 	BUILD_BUG_ON(NILFS_MAX_VOLUME_NAME >= FSLABEL_MAX);
1246 
1247 	down_read(&nilfs->ns_sem);
1248 	memtostr_pad(label, nilfs->ns_sbp[0]->s_volume_name);
1249 	up_read(&nilfs->ns_sem);
1250 
1251 	if (copy_to_user(argp, label, sizeof(label)))
1252 		return -EFAULT;
1253 	return 0;
1254 }
1255 
1256 /**
1257  * nilfs_ioctl_set_fslabel - set the volume name of the file system
1258  * @sb:   super block instance
1259  * @filp: file object
1260  * @argp: pointer to userspace memory that contains the volume name
1261  *
1262  * Return: 0 on success, or one of the following negative error codes on
1263  * failure:
1264  * * %-EFAULT	- Error copying input data.
1265  * * %-EINVAL	- Label length exceeds record size in superblock.
1266  * * %-EIO	- I/O error.
1267  * * %-EPERM	- Operation not permitted (insufficient permissions).
1268  * * %-EROFS	- Read only file system.
1269  */
1270 static int nilfs_ioctl_set_fslabel(struct super_block *sb, struct file *filp,
1271 				   void __user *argp)
1272 {
1273 	char label[NILFS_MAX_VOLUME_NAME + 1];
1274 	struct the_nilfs *nilfs = sb->s_fs_info;
1275 	struct nilfs_super_block **sbp;
1276 	size_t len;
1277 	int ret;
1278 
1279 	if (!capable(CAP_SYS_ADMIN))
1280 		return -EPERM;
1281 
1282 	ret = mnt_want_write_file(filp);
1283 	if (ret)
1284 		return ret;
1285 
1286 	if (copy_from_user(label, argp, NILFS_MAX_VOLUME_NAME + 1)) {
1287 		ret = -EFAULT;
1288 		goto out_drop_write;
1289 	}
1290 
1291 	len = strnlen(label, NILFS_MAX_VOLUME_NAME + 1);
1292 	if (len > NILFS_MAX_VOLUME_NAME) {
1293 		nilfs_err(sb, "unable to set label with more than %zu bytes",
1294 			  NILFS_MAX_VOLUME_NAME);
1295 		ret = -EINVAL;
1296 		goto out_drop_write;
1297 	}
1298 
1299 	down_write(&nilfs->ns_sem);
1300 	sbp = nilfs_prepare_super(sb, false);
1301 	if (unlikely(!sbp)) {
1302 		ret = -EIO;
1303 		goto out_unlock;
1304 	}
1305 
1306 	strtomem_pad(sbp[0]->s_volume_name, label, 0);
1307 	if (sbp[1])
1308 		strtomem_pad(sbp[1]->s_volume_name, label, 0);
1309 
1310 	ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
1311 
1312 out_unlock:
1313 	up_write(&nilfs->ns_sem);
1314 out_drop_write:
1315 	mnt_drop_write_file(filp);
1316 	return ret;
1317 }
1318 
1319 long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1320 {
1321 	struct inode *inode = file_inode(filp);
1322 	void __user *argp = (void __user *)arg;
1323 
1324 	switch (cmd) {
1325 	case FS_IOC_GETVERSION:
1326 		return nilfs_ioctl_getversion(inode, argp);
1327 	case NILFS_IOCTL_CHANGE_CPMODE:
1328 		return nilfs_ioctl_change_cpmode(inode, filp, cmd, argp);
1329 	case NILFS_IOCTL_DELETE_CHECKPOINT:
1330 		return nilfs_ioctl_delete_checkpoint(inode, filp, cmd, argp);
1331 	case NILFS_IOCTL_GET_CPINFO:
1332 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
1333 					    sizeof(struct nilfs_cpinfo),
1334 					    nilfs_ioctl_do_get_cpinfo);
1335 	case NILFS_IOCTL_GET_CPSTAT:
1336 		return nilfs_ioctl_get_cpstat(inode, filp, cmd, argp);
1337 	case NILFS_IOCTL_GET_SUINFO:
1338 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
1339 					    sizeof(struct nilfs_suinfo),
1340 					    nilfs_ioctl_do_get_suinfo);
1341 	case NILFS_IOCTL_SET_SUINFO:
1342 		return nilfs_ioctl_set_suinfo(inode, filp, cmd, argp);
1343 	case NILFS_IOCTL_GET_SUSTAT:
1344 		return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
1345 	case NILFS_IOCTL_GET_VINFO:
1346 		return nilfs_ioctl_get_info(inode, filp, cmd, argp,
1347 					    sizeof(struct nilfs_vinfo),
1348 					    nilfs_ioctl_do_get_vinfo);
1349 	case NILFS_IOCTL_GET_BDESCS:
1350 		return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
1351 	case NILFS_IOCTL_CLEAN_SEGMENTS:
1352 		return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
1353 	case NILFS_IOCTL_SYNC:
1354 		return nilfs_ioctl_sync(inode, filp, cmd, argp);
1355 	case NILFS_IOCTL_RESIZE:
1356 		return nilfs_ioctl_resize(inode, filp, argp);
1357 	case NILFS_IOCTL_SET_ALLOC_RANGE:
1358 		return nilfs_ioctl_set_alloc_range(inode, argp);
1359 	case FITRIM:
1360 		return nilfs_ioctl_trim_fs(inode, argp);
1361 	case FS_IOC_GETFSLABEL:
1362 		return nilfs_ioctl_get_fslabel(inode->i_sb, argp);
1363 	case FS_IOC_SETFSLABEL:
1364 		return nilfs_ioctl_set_fslabel(inode->i_sb, filp, argp);
1365 	default:
1366 		return -ENOTTY;
1367 	}
1368 }
1369 
1370 #ifdef CONFIG_COMPAT
1371 long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1372 {
1373 	switch (cmd) {
1374 	case FS_IOC32_GETVERSION:
1375 		cmd = FS_IOC_GETVERSION;
1376 		break;
1377 	case NILFS_IOCTL_CHANGE_CPMODE:
1378 	case NILFS_IOCTL_DELETE_CHECKPOINT:
1379 	case NILFS_IOCTL_GET_CPINFO:
1380 	case NILFS_IOCTL_GET_CPSTAT:
1381 	case NILFS_IOCTL_GET_SUINFO:
1382 	case NILFS_IOCTL_SET_SUINFO:
1383 	case NILFS_IOCTL_GET_SUSTAT:
1384 	case NILFS_IOCTL_GET_VINFO:
1385 	case NILFS_IOCTL_GET_BDESCS:
1386 	case NILFS_IOCTL_CLEAN_SEGMENTS:
1387 	case NILFS_IOCTL_SYNC:
1388 	case NILFS_IOCTL_RESIZE:
1389 	case NILFS_IOCTL_SET_ALLOC_RANGE:
1390 	case FITRIM:
1391 	case FS_IOC_GETFSLABEL:
1392 	case FS_IOC_SETFSLABEL:
1393 		break;
1394 	default:
1395 		return -ENOIOCTLCMD;
1396 	}
1397 	return nilfs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1398 }
1399 #endif
1400