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v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/ioctl.c
  4 *
  5 *  Copyright (C) 1991, 1992  Linus Torvalds
  6 */
  7
  8#include <linux/syscalls.h>
  9#include <linux/mm.h>
 10#include <linux/capability.h>
 11#include <linux/file.h>
 12#include <linux/fs.h>
 13#include <linux/security.h>
 14#include <linux/export.h>
 15#include <linux/uaccess.h>
 16#include <linux/writeback.h>
 17#include <linux/buffer_head.h>
 18#include <linux/falloc.h>
 19#include <linux/sched/signal.h>
 20
 21#include "internal.h"
 22
 23#include <asm/ioctls.h>
 24
 25/* So that the fiemap access checks can't overflow on 32 bit machines. */
 26#define FIEMAP_MAX_EXTENTS	(UINT_MAX / sizeof(struct fiemap_extent))
 27
 28/**
 29 * vfs_ioctl - call filesystem specific ioctl methods
 30 * @filp:	open file to invoke ioctl method on
 31 * @cmd:	ioctl command to execute
 32 * @arg:	command-specific argument for ioctl
 33 *
 34 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
 35 * returns -ENOTTY.
 36 *
 37 * Returns 0 on success, -errno on error.
 38 */
 39long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 40{
 41	int error = -ENOTTY;
 42
 43	if (!filp->f_op->unlocked_ioctl)
 44		goto out;
 45
 46	error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
 47	if (error == -ENOIOCTLCMD)
 48		error = -ENOTTY;
 49 out:
 50	return error;
 51}
 
 52
 53static int ioctl_fibmap(struct file *filp, int __user *p)
 54{
 55	struct address_space *mapping = filp->f_mapping;
 56	int res, block;
 57
 58	/* do we support this mess? */
 59	if (!mapping->a_ops->bmap)
 60		return -EINVAL;
 61	if (!capable(CAP_SYS_RAWIO))
 62		return -EPERM;
 63	res = get_user(block, p);
 64	if (res)
 65		return res;
 66	res = mapping->a_ops->bmap(mapping, block);
 67	return put_user(res, p);
 68}
 69
 70/**
 71 * fiemap_fill_next_extent - Fiemap helper function
 72 * @fieinfo:	Fiemap context passed into ->fiemap
 73 * @logical:	Extent logical start offset, in bytes
 74 * @phys:	Extent physical start offset, in bytes
 75 * @len:	Extent length, in bytes
 76 * @flags:	FIEMAP_EXTENT flags that describe this extent
 77 *
 78 * Called from file system ->fiemap callback. Will populate extent
 79 * info as passed in via arguments and copy to user memory. On
 80 * success, extent count on fieinfo is incremented.
 81 *
 82 * Returns 0 on success, -errno on error, 1 if this was the last
 83 * extent that will fit in user array.
 84 */
 85#define SET_UNKNOWN_FLAGS	(FIEMAP_EXTENT_DELALLOC)
 86#define SET_NO_UNMOUNTED_IO_FLAGS	(FIEMAP_EXTENT_DATA_ENCRYPTED)
 87#define SET_NOT_ALIGNED_FLAGS	(FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
 88int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
 89			    u64 phys, u64 len, u32 flags)
 90{
 91	struct fiemap_extent extent;
 92	struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
 93
 94	/* only count the extents */
 95	if (fieinfo->fi_extents_max == 0) {
 96		fieinfo->fi_extents_mapped++;
 97		return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 98	}
 99
100	if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
101		return 1;
102
103	if (flags & SET_UNKNOWN_FLAGS)
104		flags |= FIEMAP_EXTENT_UNKNOWN;
105	if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
106		flags |= FIEMAP_EXTENT_ENCODED;
107	if (flags & SET_NOT_ALIGNED_FLAGS)
108		flags |= FIEMAP_EXTENT_NOT_ALIGNED;
109
110	memset(&extent, 0, sizeof(extent));
111	extent.fe_logical = logical;
112	extent.fe_physical = phys;
113	extent.fe_length = len;
114	extent.fe_flags = flags;
115
116	dest += fieinfo->fi_extents_mapped;
117	if (copy_to_user(dest, &extent, sizeof(extent)))
118		return -EFAULT;
119
120	fieinfo->fi_extents_mapped++;
121	if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
122		return 1;
123	return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
124}
125EXPORT_SYMBOL(fiemap_fill_next_extent);
126
127/**
128 * fiemap_check_flags - check validity of requested flags for fiemap
129 * @fieinfo:	Fiemap context passed into ->fiemap
130 * @fs_flags:	Set of fiemap flags that the file system understands
131 *
132 * Called from file system ->fiemap callback. This will compute the
133 * intersection of valid fiemap flags and those that the fs supports. That
134 * value is then compared against the user supplied flags. In case of bad user
135 * flags, the invalid values will be written into the fieinfo structure, and
136 * -EBADR is returned, which tells ioctl_fiemap() to return those values to
137 * userspace. For this reason, a return code of -EBADR should be preserved.
138 *
139 * Returns 0 on success, -EBADR on bad flags.
140 */
141int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
142{
143	u32 incompat_flags;
144
145	incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
146	if (incompat_flags) {
147		fieinfo->fi_flags = incompat_flags;
148		return -EBADR;
149	}
150	return 0;
151}
152EXPORT_SYMBOL(fiemap_check_flags);
153
154static int fiemap_check_ranges(struct super_block *sb,
155			       u64 start, u64 len, u64 *new_len)
156{
157	u64 maxbytes = (u64) sb->s_maxbytes;
158
159	*new_len = len;
160
161	if (len == 0)
162		return -EINVAL;
163
164	if (start > maxbytes)
165		return -EFBIG;
166
167	/*
168	 * Shrink request scope to what the fs can actually handle.
169	 */
170	if (len > maxbytes || (maxbytes - len) < start)
171		*new_len = maxbytes - start;
172
173	return 0;
174}
175
176static int ioctl_fiemap(struct file *filp, unsigned long arg)
177{
178	struct fiemap fiemap;
179	struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
180	struct fiemap_extent_info fieinfo = { 0, };
181	struct inode *inode = file_inode(filp);
182	struct super_block *sb = inode->i_sb;
183	u64 len;
184	int error;
185
186	if (!inode->i_op->fiemap)
187		return -EOPNOTSUPP;
188
189	if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
190		return -EFAULT;
191
192	if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
193		return -EINVAL;
194
195	error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
196				    &len);
197	if (error)
198		return error;
199
200	fieinfo.fi_flags = fiemap.fm_flags;
201	fieinfo.fi_extents_max = fiemap.fm_extent_count;
202	fieinfo.fi_extents_start = ufiemap->fm_extents;
203
204	if (fiemap.fm_extent_count != 0 &&
205	    !access_ok(VERIFY_WRITE, fieinfo.fi_extents_start,
206		       fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
207		return -EFAULT;
208
209	if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
210		filemap_write_and_wait(inode->i_mapping);
211
212	error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
213	fiemap.fm_flags = fieinfo.fi_flags;
214	fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
215	if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
216		error = -EFAULT;
217
218	return error;
219}
220
221static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
222			     u64 off, u64 olen, u64 destoff)
223{
224	struct fd src_file = fdget(srcfd);
 
225	int ret;
226
227	if (!src_file.file)
228		return -EBADF;
229	ret = -EXDEV;
230	if (src_file.file->f_path.mnt != dst_file->f_path.mnt)
231		goto fdput;
232	ret = do_clone_file_range(src_file.file, off, dst_file, destoff, olen);
 
 
 
 
 
 
 
233fdput:
234	fdput(src_file);
235	return ret;
236}
237
238static long ioctl_file_clone_range(struct file *file, void __user *argp)
239{
240	struct file_clone_range args;
241
242	if (copy_from_user(&args, argp, sizeof(args)))
243		return -EFAULT;
244	return ioctl_file_clone(file, args.src_fd, args.src_offset,
245				args.src_length, args.dest_offset);
246}
247
248#ifdef CONFIG_BLOCK
249
250static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
251{
252	return (offset >> inode->i_blkbits);
253}
254
255static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
256{
257	return (blk << inode->i_blkbits);
258}
259
260/**
261 * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
262 * @inode: the inode to map
263 * @fieinfo: the fiemap info struct that will be passed back to userspace
264 * @start: where to start mapping in the inode
265 * @len: how much space to map
266 * @get_block: the fs's get_block function
267 *
268 * This does FIEMAP for block based inodes.  Basically it will just loop
269 * through get_block until we hit the number of extents we want to map, or we
270 * go past the end of the file and hit a hole.
271 *
272 * If it is possible to have data blocks beyond a hole past @inode->i_size, then
273 * please do not use this function, it will stop at the first unmapped block
274 * beyond i_size.
275 *
276 * If you use this function directly, you need to do your own locking. Use
277 * generic_block_fiemap if you want the locking done for you.
278 */
279
280int __generic_block_fiemap(struct inode *inode,
281			   struct fiemap_extent_info *fieinfo, loff_t start,
282			   loff_t len, get_block_t *get_block)
283{
284	struct buffer_head map_bh;
285	sector_t start_blk, last_blk;
286	loff_t isize = i_size_read(inode);
287	u64 logical = 0, phys = 0, size = 0;
288	u32 flags = FIEMAP_EXTENT_MERGED;
289	bool past_eof = false, whole_file = false;
290	int ret = 0;
291
292	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
293	if (ret)
294		return ret;
295
296	/*
297	 * Either the i_mutex or other appropriate locking needs to be held
298	 * since we expect isize to not change at all through the duration of
299	 * this call.
300	 */
301	if (len >= isize) {
302		whole_file = true;
303		len = isize;
304	}
305
306	/*
307	 * Some filesystems can't deal with being asked to map less than
308	 * blocksize, so make sure our len is at least block length.
309	 */
310	if (logical_to_blk(inode, len) == 0)
311		len = blk_to_logical(inode, 1);
312
313	start_blk = logical_to_blk(inode, start);
314	last_blk = logical_to_blk(inode, start + len - 1);
315
316	do {
317		/*
318		 * we set b_size to the total size we want so it will map as
319		 * many contiguous blocks as possible at once
320		 */
321		memset(&map_bh, 0, sizeof(struct buffer_head));
322		map_bh.b_size = len;
323
324		ret = get_block(inode, start_blk, &map_bh, 0);
325		if (ret)
326			break;
327
328		/* HOLE */
329		if (!buffer_mapped(&map_bh)) {
330			start_blk++;
331
332			/*
333			 * We want to handle the case where there is an
334			 * allocated block at the front of the file, and then
335			 * nothing but holes up to the end of the file properly,
336			 * to make sure that extent at the front gets properly
337			 * marked with FIEMAP_EXTENT_LAST
338			 */
339			if (!past_eof &&
340			    blk_to_logical(inode, start_blk) >= isize)
341				past_eof = 1;
342
343			/*
344			 * First hole after going past the EOF, this is our
345			 * last extent
346			 */
347			if (past_eof && size) {
348				flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
349				ret = fiemap_fill_next_extent(fieinfo, logical,
350							      phys, size,
351							      flags);
352			} else if (size) {
353				ret = fiemap_fill_next_extent(fieinfo, logical,
354							      phys, size, flags);
355				size = 0;
356			}
357
358			/* if we have holes up to/past EOF then we're done */
359			if (start_blk > last_blk || past_eof || ret)
360				break;
361		} else {
362			/*
363			 * We have gone over the length of what we wanted to
364			 * map, and it wasn't the entire file, so add the extent
365			 * we got last time and exit.
366			 *
367			 * This is for the case where say we want to map all the
368			 * way up to the second to the last block in a file, but
369			 * the last block is a hole, making the second to last
370			 * block FIEMAP_EXTENT_LAST.  In this case we want to
371			 * see if there is a hole after the second to last block
372			 * so we can mark it properly.  If we found data after
373			 * we exceeded the length we were requesting, then we
374			 * are good to go, just add the extent to the fieinfo
375			 * and break
376			 */
377			if (start_blk > last_blk && !whole_file) {
378				ret = fiemap_fill_next_extent(fieinfo, logical,
379							      phys, size,
380							      flags);
381				break;
382			}
383
384			/*
385			 * if size != 0 then we know we already have an extent
386			 * to add, so add it.
387			 */
388			if (size) {
389				ret = fiemap_fill_next_extent(fieinfo, logical,
390							      phys, size,
391							      flags);
392				if (ret)
393					break;
394			}
395
396			logical = blk_to_logical(inode, start_blk);
397			phys = blk_to_logical(inode, map_bh.b_blocknr);
398			size = map_bh.b_size;
399			flags = FIEMAP_EXTENT_MERGED;
400
401			start_blk += logical_to_blk(inode, size);
402
403			/*
404			 * If we are past the EOF, then we need to make sure as
405			 * soon as we find a hole that the last extent we found
406			 * is marked with FIEMAP_EXTENT_LAST
407			 */
408			if (!past_eof && logical + size >= isize)
409				past_eof = true;
410		}
411		cond_resched();
412		if (fatal_signal_pending(current)) {
413			ret = -EINTR;
414			break;
415		}
416
417	} while (1);
418
419	/* If ret is 1 then we just hit the end of the extent array */
420	if (ret == 1)
421		ret = 0;
422
423	return ret;
424}
425EXPORT_SYMBOL(__generic_block_fiemap);
426
427/**
428 * generic_block_fiemap - FIEMAP for block based inodes
429 * @inode: The inode to map
430 * @fieinfo: The mapping information
431 * @start: The initial block to map
432 * @len: The length of the extect to attempt to map
433 * @get_block: The block mapping function for the fs
434 *
435 * Calls __generic_block_fiemap to map the inode, after taking
436 * the inode's mutex lock.
437 */
438
439int generic_block_fiemap(struct inode *inode,
440			 struct fiemap_extent_info *fieinfo, u64 start,
441			 u64 len, get_block_t *get_block)
442{
443	int ret;
444	inode_lock(inode);
445	ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
446	inode_unlock(inode);
447	return ret;
448}
449EXPORT_SYMBOL(generic_block_fiemap);
450
451#endif  /*  CONFIG_BLOCK  */
452
453/*
454 * This provides compatibility with legacy XFS pre-allocation ioctls
455 * which predate the fallocate syscall.
456 *
457 * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
458 * are used here, rest are ignored.
459 */
460int ioctl_preallocate(struct file *filp, void __user *argp)
461{
462	struct inode *inode = file_inode(filp);
463	struct space_resv sr;
464
465	if (copy_from_user(&sr, argp, sizeof(sr)))
466		return -EFAULT;
467
468	switch (sr.l_whence) {
469	case SEEK_SET:
470		break;
471	case SEEK_CUR:
472		sr.l_start += filp->f_pos;
473		break;
474	case SEEK_END:
475		sr.l_start += i_size_read(inode);
476		break;
477	default:
478		return -EINVAL;
479	}
480
481	return vfs_fallocate(filp, FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
482}
483
484static int file_ioctl(struct file *filp, unsigned int cmd,
485		unsigned long arg)
486{
487	struct inode *inode = file_inode(filp);
488	int __user *p = (int __user *)arg;
489
490	switch (cmd) {
491	case FIBMAP:
492		return ioctl_fibmap(filp, p);
493	case FIONREAD:
494		return put_user(i_size_read(inode) - filp->f_pos, p);
495	case FS_IOC_RESVSP:
496	case FS_IOC_RESVSP64:
497		return ioctl_preallocate(filp, p);
498	}
499
500	return vfs_ioctl(filp, cmd, arg);
501}
502
503static int ioctl_fionbio(struct file *filp, int __user *argp)
504{
505	unsigned int flag;
506	int on, error;
507
508	error = get_user(on, argp);
509	if (error)
510		return error;
511	flag = O_NONBLOCK;
512#ifdef __sparc__
513	/* SunOS compatibility item. */
514	if (O_NONBLOCK != O_NDELAY)
515		flag |= O_NDELAY;
516#endif
517	spin_lock(&filp->f_lock);
518	if (on)
519		filp->f_flags |= flag;
520	else
521		filp->f_flags &= ~flag;
522	spin_unlock(&filp->f_lock);
523	return error;
524}
525
526static int ioctl_fioasync(unsigned int fd, struct file *filp,
527			  int __user *argp)
528{
529	unsigned int flag;
530	int on, error;
531
532	error = get_user(on, argp);
533	if (error)
534		return error;
535	flag = on ? FASYNC : 0;
536
537	/* Did FASYNC state change ? */
538	if ((flag ^ filp->f_flags) & FASYNC) {
539		if (filp->f_op->fasync)
540			/* fasync() adjusts filp->f_flags */
541			error = filp->f_op->fasync(fd, filp, on);
542		else
543			error = -ENOTTY;
544	}
545	return error < 0 ? error : 0;
546}
547
548static int ioctl_fsfreeze(struct file *filp)
549{
550	struct super_block *sb = file_inode(filp)->i_sb;
551
552	if (!capable(CAP_SYS_ADMIN))
553		return -EPERM;
554
555	/* If filesystem doesn't support freeze feature, return. */
556	if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
557		return -EOPNOTSUPP;
558
559	/* Freeze */
560	if (sb->s_op->freeze_super)
561		return sb->s_op->freeze_super(sb);
562	return freeze_super(sb);
563}
564
565static int ioctl_fsthaw(struct file *filp)
566{
567	struct super_block *sb = file_inode(filp)->i_sb;
568
569	if (!capable(CAP_SYS_ADMIN))
570		return -EPERM;
571
572	/* Thaw */
573	if (sb->s_op->thaw_super)
574		return sb->s_op->thaw_super(sb);
575	return thaw_super(sb);
576}
577
578static int ioctl_file_dedupe_range(struct file *file, void __user *arg)
579{
580	struct file_dedupe_range __user *argp = arg;
581	struct file_dedupe_range *same = NULL;
582	int ret;
583	unsigned long size;
584	u16 count;
585
586	if (get_user(count, &argp->dest_count)) {
587		ret = -EFAULT;
588		goto out;
589	}
590
591	size = offsetof(struct file_dedupe_range __user, info[count]);
592	if (size > PAGE_SIZE) {
593		ret = -ENOMEM;
594		goto out;
595	}
596
597	same = memdup_user(argp, size);
598	if (IS_ERR(same)) {
599		ret = PTR_ERR(same);
600		same = NULL;
601		goto out;
602	}
603
604	same->dest_count = count;
605	ret = vfs_dedupe_file_range(file, same);
606	if (ret)
607		goto out;
608
609	ret = copy_to_user(argp, same, size);
610	if (ret)
611		ret = -EFAULT;
612
613out:
614	kfree(same);
615	return ret;
616}
617
618/*
619 * When you add any new common ioctls to the switches above and below
620 * please update compat_sys_ioctl() too.
621 *
622 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
623 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
624 */
625int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
626	     unsigned long arg)
627{
628	int error = 0;
629	int __user *argp = (int __user *)arg;
630	struct inode *inode = file_inode(filp);
631
632	switch (cmd) {
633	case FIOCLEX:
634		set_close_on_exec(fd, 1);
635		break;
636
637	case FIONCLEX:
638		set_close_on_exec(fd, 0);
639		break;
640
641	case FIONBIO:
642		error = ioctl_fionbio(filp, argp);
643		break;
644
645	case FIOASYNC:
646		error = ioctl_fioasync(fd, filp, argp);
647		break;
648
649	case FIOQSIZE:
650		if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
651		    S_ISLNK(inode->i_mode)) {
652			loff_t res = inode_get_bytes(inode);
653			error = copy_to_user(argp, &res, sizeof(res)) ?
654					-EFAULT : 0;
655		} else
656			error = -ENOTTY;
657		break;
658
659	case FIFREEZE:
660		error = ioctl_fsfreeze(filp);
661		break;
662
663	case FITHAW:
664		error = ioctl_fsthaw(filp);
665		break;
666
667	case FS_IOC_FIEMAP:
668		return ioctl_fiemap(filp, arg);
669
670	case FIGETBSZ:
 
 
 
671		return put_user(inode->i_sb->s_blocksize, argp);
672
673	case FICLONE:
674		return ioctl_file_clone(filp, arg, 0, 0, 0);
675
676	case FICLONERANGE:
677		return ioctl_file_clone_range(filp, argp);
678
679	case FIDEDUPERANGE:
680		return ioctl_file_dedupe_range(filp, argp);
681
682	default:
683		if (S_ISREG(inode->i_mode))
684			error = file_ioctl(filp, cmd, arg);
685		else
686			error = vfs_ioctl(filp, cmd, arg);
687		break;
688	}
689	return error;
690}
691
692int ksys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
693{
694	int error;
695	struct fd f = fdget(fd);
696
697	if (!f.file)
698		return -EBADF;
699	error = security_file_ioctl(f.file, cmd, arg);
700	if (!error)
701		error = do_vfs_ioctl(f.file, fd, cmd, arg);
702	fdput(f);
703	return error;
704}
705
706SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
707{
708	return ksys_ioctl(fd, cmd, arg);
709}
v5.4
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/ioctl.c
  4 *
  5 *  Copyright (C) 1991, 1992  Linus Torvalds
  6 */
  7
  8#include <linux/syscalls.h>
  9#include <linux/mm.h>
 10#include <linux/capability.h>
 11#include <linux/file.h>
 12#include <linux/fs.h>
 13#include <linux/security.h>
 14#include <linux/export.h>
 15#include <linux/uaccess.h>
 16#include <linux/writeback.h>
 17#include <linux/buffer_head.h>
 18#include <linux/falloc.h>
 19#include <linux/sched/signal.h>
 20
 21#include "internal.h"
 22
 23#include <asm/ioctls.h>
 24
 25/* So that the fiemap access checks can't overflow on 32 bit machines. */
 26#define FIEMAP_MAX_EXTENTS	(UINT_MAX / sizeof(struct fiemap_extent))
 27
 28/**
 29 * vfs_ioctl - call filesystem specific ioctl methods
 30 * @filp:	open file to invoke ioctl method on
 31 * @cmd:	ioctl command to execute
 32 * @arg:	command-specific argument for ioctl
 33 *
 34 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
 35 * returns -ENOTTY.
 36 *
 37 * Returns 0 on success, -errno on error.
 38 */
 39long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 40{
 41	int error = -ENOTTY;
 42
 43	if (!filp->f_op->unlocked_ioctl)
 44		goto out;
 45
 46	error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
 47	if (error == -ENOIOCTLCMD)
 48		error = -ENOTTY;
 49 out:
 50	return error;
 51}
 52EXPORT_SYMBOL(vfs_ioctl);
 53
 54static int ioctl_fibmap(struct file *filp, int __user *p)
 55{
 56	struct address_space *mapping = filp->f_mapping;
 57	int res, block;
 58
 59	/* do we support this mess? */
 60	if (!mapping->a_ops->bmap)
 61		return -EINVAL;
 62	if (!capable(CAP_SYS_RAWIO))
 63		return -EPERM;
 64	res = get_user(block, p);
 65	if (res)
 66		return res;
 67	res = mapping->a_ops->bmap(mapping, block);
 68	return put_user(res, p);
 69}
 70
 71/**
 72 * fiemap_fill_next_extent - Fiemap helper function
 73 * @fieinfo:	Fiemap context passed into ->fiemap
 74 * @logical:	Extent logical start offset, in bytes
 75 * @phys:	Extent physical start offset, in bytes
 76 * @len:	Extent length, in bytes
 77 * @flags:	FIEMAP_EXTENT flags that describe this extent
 78 *
 79 * Called from file system ->fiemap callback. Will populate extent
 80 * info as passed in via arguments and copy to user memory. On
 81 * success, extent count on fieinfo is incremented.
 82 *
 83 * Returns 0 on success, -errno on error, 1 if this was the last
 84 * extent that will fit in user array.
 85 */
 86#define SET_UNKNOWN_FLAGS	(FIEMAP_EXTENT_DELALLOC)
 87#define SET_NO_UNMOUNTED_IO_FLAGS	(FIEMAP_EXTENT_DATA_ENCRYPTED)
 88#define SET_NOT_ALIGNED_FLAGS	(FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
 89int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
 90			    u64 phys, u64 len, u32 flags)
 91{
 92	struct fiemap_extent extent;
 93	struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
 94
 95	/* only count the extents */
 96	if (fieinfo->fi_extents_max == 0) {
 97		fieinfo->fi_extents_mapped++;
 98		return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 99	}
100
101	if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
102		return 1;
103
104	if (flags & SET_UNKNOWN_FLAGS)
105		flags |= FIEMAP_EXTENT_UNKNOWN;
106	if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
107		flags |= FIEMAP_EXTENT_ENCODED;
108	if (flags & SET_NOT_ALIGNED_FLAGS)
109		flags |= FIEMAP_EXTENT_NOT_ALIGNED;
110
111	memset(&extent, 0, sizeof(extent));
112	extent.fe_logical = logical;
113	extent.fe_physical = phys;
114	extent.fe_length = len;
115	extent.fe_flags = flags;
116
117	dest += fieinfo->fi_extents_mapped;
118	if (copy_to_user(dest, &extent, sizeof(extent)))
119		return -EFAULT;
120
121	fieinfo->fi_extents_mapped++;
122	if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
123		return 1;
124	return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
125}
126EXPORT_SYMBOL(fiemap_fill_next_extent);
127
128/**
129 * fiemap_check_flags - check validity of requested flags for fiemap
130 * @fieinfo:	Fiemap context passed into ->fiemap
131 * @fs_flags:	Set of fiemap flags that the file system understands
132 *
133 * Called from file system ->fiemap callback. This will compute the
134 * intersection of valid fiemap flags and those that the fs supports. That
135 * value is then compared against the user supplied flags. In case of bad user
136 * flags, the invalid values will be written into the fieinfo structure, and
137 * -EBADR is returned, which tells ioctl_fiemap() to return those values to
138 * userspace. For this reason, a return code of -EBADR should be preserved.
139 *
140 * Returns 0 on success, -EBADR on bad flags.
141 */
142int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
143{
144	u32 incompat_flags;
145
146	incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
147	if (incompat_flags) {
148		fieinfo->fi_flags = incompat_flags;
149		return -EBADR;
150	}
151	return 0;
152}
153EXPORT_SYMBOL(fiemap_check_flags);
154
155static int fiemap_check_ranges(struct super_block *sb,
156			       u64 start, u64 len, u64 *new_len)
157{
158	u64 maxbytes = (u64) sb->s_maxbytes;
159
160	*new_len = len;
161
162	if (len == 0)
163		return -EINVAL;
164
165	if (start > maxbytes)
166		return -EFBIG;
167
168	/*
169	 * Shrink request scope to what the fs can actually handle.
170	 */
171	if (len > maxbytes || (maxbytes - len) < start)
172		*new_len = maxbytes - start;
173
174	return 0;
175}
176
177static int ioctl_fiemap(struct file *filp, unsigned long arg)
178{
179	struct fiemap fiemap;
180	struct fiemap __user *ufiemap = (struct fiemap __user *) arg;
181	struct fiemap_extent_info fieinfo = { 0, };
182	struct inode *inode = file_inode(filp);
183	struct super_block *sb = inode->i_sb;
184	u64 len;
185	int error;
186
187	if (!inode->i_op->fiemap)
188		return -EOPNOTSUPP;
189
190	if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
191		return -EFAULT;
192
193	if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
194		return -EINVAL;
195
196	error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
197				    &len);
198	if (error)
199		return error;
200
201	fieinfo.fi_flags = fiemap.fm_flags;
202	fieinfo.fi_extents_max = fiemap.fm_extent_count;
203	fieinfo.fi_extents_start = ufiemap->fm_extents;
204
205	if (fiemap.fm_extent_count != 0 &&
206	    !access_ok(fieinfo.fi_extents_start,
207		       fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
208		return -EFAULT;
209
210	if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
211		filemap_write_and_wait(inode->i_mapping);
212
213	error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
214	fiemap.fm_flags = fieinfo.fi_flags;
215	fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
216	if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
217		error = -EFAULT;
218
219	return error;
220}
221
222static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
223			     u64 off, u64 olen, u64 destoff)
224{
225	struct fd src_file = fdget(srcfd);
226	loff_t cloned;
227	int ret;
228
229	if (!src_file.file)
230		return -EBADF;
231	ret = -EXDEV;
232	if (src_file.file->f_path.mnt != dst_file->f_path.mnt)
233		goto fdput;
234	cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
235				      olen, 0);
236	if (cloned < 0)
237		ret = cloned;
238	else if (olen && cloned != olen)
239		ret = -EINVAL;
240	else
241		ret = 0;
242fdput:
243	fdput(src_file);
244	return ret;
245}
246
247static long ioctl_file_clone_range(struct file *file, void __user *argp)
248{
249	struct file_clone_range args;
250
251	if (copy_from_user(&args, argp, sizeof(args)))
252		return -EFAULT;
253	return ioctl_file_clone(file, args.src_fd, args.src_offset,
254				args.src_length, args.dest_offset);
255}
256
257#ifdef CONFIG_BLOCK
258
259static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
260{
261	return (offset >> inode->i_blkbits);
262}
263
264static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
265{
266	return (blk << inode->i_blkbits);
267}
268
269/**
270 * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
271 * @inode: the inode to map
272 * @fieinfo: the fiemap info struct that will be passed back to userspace
273 * @start: where to start mapping in the inode
274 * @len: how much space to map
275 * @get_block: the fs's get_block function
276 *
277 * This does FIEMAP for block based inodes.  Basically it will just loop
278 * through get_block until we hit the number of extents we want to map, or we
279 * go past the end of the file and hit a hole.
280 *
281 * If it is possible to have data blocks beyond a hole past @inode->i_size, then
282 * please do not use this function, it will stop at the first unmapped block
283 * beyond i_size.
284 *
285 * If you use this function directly, you need to do your own locking. Use
286 * generic_block_fiemap if you want the locking done for you.
287 */
288
289int __generic_block_fiemap(struct inode *inode,
290			   struct fiemap_extent_info *fieinfo, loff_t start,
291			   loff_t len, get_block_t *get_block)
292{
293	struct buffer_head map_bh;
294	sector_t start_blk, last_blk;
295	loff_t isize = i_size_read(inode);
296	u64 logical = 0, phys = 0, size = 0;
297	u32 flags = FIEMAP_EXTENT_MERGED;
298	bool past_eof = false, whole_file = false;
299	int ret = 0;
300
301	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
302	if (ret)
303		return ret;
304
305	/*
306	 * Either the i_mutex or other appropriate locking needs to be held
307	 * since we expect isize to not change at all through the duration of
308	 * this call.
309	 */
310	if (len >= isize) {
311		whole_file = true;
312		len = isize;
313	}
314
315	/*
316	 * Some filesystems can't deal with being asked to map less than
317	 * blocksize, so make sure our len is at least block length.
318	 */
319	if (logical_to_blk(inode, len) == 0)
320		len = blk_to_logical(inode, 1);
321
322	start_blk = logical_to_blk(inode, start);
323	last_blk = logical_to_blk(inode, start + len - 1);
324
325	do {
326		/*
327		 * we set b_size to the total size we want so it will map as
328		 * many contiguous blocks as possible at once
329		 */
330		memset(&map_bh, 0, sizeof(struct buffer_head));
331		map_bh.b_size = len;
332
333		ret = get_block(inode, start_blk, &map_bh, 0);
334		if (ret)
335			break;
336
337		/* HOLE */
338		if (!buffer_mapped(&map_bh)) {
339			start_blk++;
340
341			/*
342			 * We want to handle the case where there is an
343			 * allocated block at the front of the file, and then
344			 * nothing but holes up to the end of the file properly,
345			 * to make sure that extent at the front gets properly
346			 * marked with FIEMAP_EXTENT_LAST
347			 */
348			if (!past_eof &&
349			    blk_to_logical(inode, start_blk) >= isize)
350				past_eof = 1;
351
352			/*
353			 * First hole after going past the EOF, this is our
354			 * last extent
355			 */
356			if (past_eof && size) {
357				flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
358				ret = fiemap_fill_next_extent(fieinfo, logical,
359							      phys, size,
360							      flags);
361			} else if (size) {
362				ret = fiemap_fill_next_extent(fieinfo, logical,
363							      phys, size, flags);
364				size = 0;
365			}
366
367			/* if we have holes up to/past EOF then we're done */
368			if (start_blk > last_blk || past_eof || ret)
369				break;
370		} else {
371			/*
372			 * We have gone over the length of what we wanted to
373			 * map, and it wasn't the entire file, so add the extent
374			 * we got last time and exit.
375			 *
376			 * This is for the case where say we want to map all the
377			 * way up to the second to the last block in a file, but
378			 * the last block is a hole, making the second to last
379			 * block FIEMAP_EXTENT_LAST.  In this case we want to
380			 * see if there is a hole after the second to last block
381			 * so we can mark it properly.  If we found data after
382			 * we exceeded the length we were requesting, then we
383			 * are good to go, just add the extent to the fieinfo
384			 * and break
385			 */
386			if (start_blk > last_blk && !whole_file) {
387				ret = fiemap_fill_next_extent(fieinfo, logical,
388							      phys, size,
389							      flags);
390				break;
391			}
392
393			/*
394			 * if size != 0 then we know we already have an extent
395			 * to add, so add it.
396			 */
397			if (size) {
398				ret = fiemap_fill_next_extent(fieinfo, logical,
399							      phys, size,
400							      flags);
401				if (ret)
402					break;
403			}
404
405			logical = blk_to_logical(inode, start_blk);
406			phys = blk_to_logical(inode, map_bh.b_blocknr);
407			size = map_bh.b_size;
408			flags = FIEMAP_EXTENT_MERGED;
409
410			start_blk += logical_to_blk(inode, size);
411
412			/*
413			 * If we are past the EOF, then we need to make sure as
414			 * soon as we find a hole that the last extent we found
415			 * is marked with FIEMAP_EXTENT_LAST
416			 */
417			if (!past_eof && logical + size >= isize)
418				past_eof = true;
419		}
420		cond_resched();
421		if (fatal_signal_pending(current)) {
422			ret = -EINTR;
423			break;
424		}
425
426	} while (1);
427
428	/* If ret is 1 then we just hit the end of the extent array */
429	if (ret == 1)
430		ret = 0;
431
432	return ret;
433}
434EXPORT_SYMBOL(__generic_block_fiemap);
435
436/**
437 * generic_block_fiemap - FIEMAP for block based inodes
438 * @inode: The inode to map
439 * @fieinfo: The mapping information
440 * @start: The initial block to map
441 * @len: The length of the extect to attempt to map
442 * @get_block: The block mapping function for the fs
443 *
444 * Calls __generic_block_fiemap to map the inode, after taking
445 * the inode's mutex lock.
446 */
447
448int generic_block_fiemap(struct inode *inode,
449			 struct fiemap_extent_info *fieinfo, u64 start,
450			 u64 len, get_block_t *get_block)
451{
452	int ret;
453	inode_lock(inode);
454	ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
455	inode_unlock(inode);
456	return ret;
457}
458EXPORT_SYMBOL(generic_block_fiemap);
459
460#endif  /*  CONFIG_BLOCK  */
461
462/*
463 * This provides compatibility with legacy XFS pre-allocation ioctls
464 * which predate the fallocate syscall.
465 *
466 * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
467 * are used here, rest are ignored.
468 */
469int ioctl_preallocate(struct file *filp, void __user *argp)
470{
471	struct inode *inode = file_inode(filp);
472	struct space_resv sr;
473
474	if (copy_from_user(&sr, argp, sizeof(sr)))
475		return -EFAULT;
476
477	switch (sr.l_whence) {
478	case SEEK_SET:
479		break;
480	case SEEK_CUR:
481		sr.l_start += filp->f_pos;
482		break;
483	case SEEK_END:
484		sr.l_start += i_size_read(inode);
485		break;
486	default:
487		return -EINVAL;
488	}
489
490	return vfs_fallocate(filp, FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
491}
492
493static int file_ioctl(struct file *filp, unsigned int cmd,
494		unsigned long arg)
495{
496	struct inode *inode = file_inode(filp);
497	int __user *p = (int __user *)arg;
498
499	switch (cmd) {
500	case FIBMAP:
501		return ioctl_fibmap(filp, p);
502	case FIONREAD:
503		return put_user(i_size_read(inode) - filp->f_pos, p);
504	case FS_IOC_RESVSP:
505	case FS_IOC_RESVSP64:
506		return ioctl_preallocate(filp, p);
507	}
508
509	return vfs_ioctl(filp, cmd, arg);
510}
511
512static int ioctl_fionbio(struct file *filp, int __user *argp)
513{
514	unsigned int flag;
515	int on, error;
516
517	error = get_user(on, argp);
518	if (error)
519		return error;
520	flag = O_NONBLOCK;
521#ifdef __sparc__
522	/* SunOS compatibility item. */
523	if (O_NONBLOCK != O_NDELAY)
524		flag |= O_NDELAY;
525#endif
526	spin_lock(&filp->f_lock);
527	if (on)
528		filp->f_flags |= flag;
529	else
530		filp->f_flags &= ~flag;
531	spin_unlock(&filp->f_lock);
532	return error;
533}
534
535static int ioctl_fioasync(unsigned int fd, struct file *filp,
536			  int __user *argp)
537{
538	unsigned int flag;
539	int on, error;
540
541	error = get_user(on, argp);
542	if (error)
543		return error;
544	flag = on ? FASYNC : 0;
545
546	/* Did FASYNC state change ? */
547	if ((flag ^ filp->f_flags) & FASYNC) {
548		if (filp->f_op->fasync)
549			/* fasync() adjusts filp->f_flags */
550			error = filp->f_op->fasync(fd, filp, on);
551		else
552			error = -ENOTTY;
553	}
554	return error < 0 ? error : 0;
555}
556
557static int ioctl_fsfreeze(struct file *filp)
558{
559	struct super_block *sb = file_inode(filp)->i_sb;
560
561	if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
562		return -EPERM;
563
564	/* If filesystem doesn't support freeze feature, return. */
565	if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
566		return -EOPNOTSUPP;
567
568	/* Freeze */
569	if (sb->s_op->freeze_super)
570		return sb->s_op->freeze_super(sb);
571	return freeze_super(sb);
572}
573
574static int ioctl_fsthaw(struct file *filp)
575{
576	struct super_block *sb = file_inode(filp)->i_sb;
577
578	if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
579		return -EPERM;
580
581	/* Thaw */
582	if (sb->s_op->thaw_super)
583		return sb->s_op->thaw_super(sb);
584	return thaw_super(sb);
585}
586
587static int ioctl_file_dedupe_range(struct file *file, void __user *arg)
588{
589	struct file_dedupe_range __user *argp = arg;
590	struct file_dedupe_range *same = NULL;
591	int ret;
592	unsigned long size;
593	u16 count;
594
595	if (get_user(count, &argp->dest_count)) {
596		ret = -EFAULT;
597		goto out;
598	}
599
600	size = offsetof(struct file_dedupe_range __user, info[count]);
601	if (size > PAGE_SIZE) {
602		ret = -ENOMEM;
603		goto out;
604	}
605
606	same = memdup_user(argp, size);
607	if (IS_ERR(same)) {
608		ret = PTR_ERR(same);
609		same = NULL;
610		goto out;
611	}
612
613	same->dest_count = count;
614	ret = vfs_dedupe_file_range(file, same);
615	if (ret)
616		goto out;
617
618	ret = copy_to_user(argp, same, size);
619	if (ret)
620		ret = -EFAULT;
621
622out:
623	kfree(same);
624	return ret;
625}
626
627/*
628 * When you add any new common ioctls to the switches above and below
629 * please update compat_sys_ioctl() too.
630 *
631 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
632 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
633 */
634int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
635	     unsigned long arg)
636{
637	int error = 0;
638	int __user *argp = (int __user *)arg;
639	struct inode *inode = file_inode(filp);
640
641	switch (cmd) {
642	case FIOCLEX:
643		set_close_on_exec(fd, 1);
644		break;
645
646	case FIONCLEX:
647		set_close_on_exec(fd, 0);
648		break;
649
650	case FIONBIO:
651		error = ioctl_fionbio(filp, argp);
652		break;
653
654	case FIOASYNC:
655		error = ioctl_fioasync(fd, filp, argp);
656		break;
657
658	case FIOQSIZE:
659		if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
660		    S_ISLNK(inode->i_mode)) {
661			loff_t res = inode_get_bytes(inode);
662			error = copy_to_user(argp, &res, sizeof(res)) ?
663					-EFAULT : 0;
664		} else
665			error = -ENOTTY;
666		break;
667
668	case FIFREEZE:
669		error = ioctl_fsfreeze(filp);
670		break;
671
672	case FITHAW:
673		error = ioctl_fsthaw(filp);
674		break;
675
676	case FS_IOC_FIEMAP:
677		return ioctl_fiemap(filp, arg);
678
679	case FIGETBSZ:
680		/* anon_bdev filesystems may not have a block size */
681		if (!inode->i_sb->s_blocksize)
682			return -EINVAL;
683		return put_user(inode->i_sb->s_blocksize, argp);
684
685	case FICLONE:
686		return ioctl_file_clone(filp, arg, 0, 0, 0);
687
688	case FICLONERANGE:
689		return ioctl_file_clone_range(filp, argp);
690
691	case FIDEDUPERANGE:
692		return ioctl_file_dedupe_range(filp, argp);
693
694	default:
695		if (S_ISREG(inode->i_mode))
696			error = file_ioctl(filp, cmd, arg);
697		else
698			error = vfs_ioctl(filp, cmd, arg);
699		break;
700	}
701	return error;
702}
703
704int ksys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
705{
706	int error;
707	struct fd f = fdget(fd);
708
709	if (!f.file)
710		return -EBADF;
711	error = security_file_ioctl(f.file, cmd, arg);
712	if (!error)
713		error = do_vfs_ioctl(f.file, fd, cmd, arg);
714	fdput(f);
715	return error;
716}
717
718SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
719{
720	return ksys_ioctl(fd, cmd, arg);
721}