xref: /openbmc/linux/fs/ntfs3/file.c (revision 60eb644b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *
4  * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
5  *
6  *  Regular file handling primitives for NTFS-based filesystems.
7  *
8  */
9 
10 #include <linux/backing-dev.h>
11 #include <linux/blkdev.h>
12 #include <linux/buffer_head.h>
13 #include <linux/compat.h>
14 #include <linux/falloc.h>
15 #include <linux/fiemap.h>
16 
17 #include "debug.h"
18 #include "ntfs.h"
19 #include "ntfs_fs.h"
20 
21 static int ntfs_ioctl_fitrim(struct ntfs_sb_info *sbi, unsigned long arg)
22 {
23 	struct fstrim_range __user *user_range;
24 	struct fstrim_range range;
25 	struct block_device *dev;
26 	int err;
27 
28 	if (!capable(CAP_SYS_ADMIN))
29 		return -EPERM;
30 
31 	dev = sbi->sb->s_bdev;
32 	if (!bdev_max_discard_sectors(dev))
33 		return -EOPNOTSUPP;
34 
35 	user_range = (struct fstrim_range __user *)arg;
36 	if (copy_from_user(&range, user_range, sizeof(range)))
37 		return -EFAULT;
38 
39 	range.minlen = max_t(u32, range.minlen, bdev_discard_granularity(dev));
40 
41 	err = ntfs_trim_fs(sbi, &range);
42 	if (err < 0)
43 		return err;
44 
45 	if (copy_to_user(user_range, &range, sizeof(range)))
46 		return -EFAULT;
47 
48 	return 0;
49 }
50 
51 static long ntfs_ioctl(struct file *filp, u32 cmd, unsigned long arg)
52 {
53 	struct inode *inode = file_inode(filp);
54 	struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;
55 
56 	switch (cmd) {
57 	case FITRIM:
58 		return ntfs_ioctl_fitrim(sbi, arg);
59 	}
60 	return -ENOTTY; /* Inappropriate ioctl for device. */
61 }
62 
63 #ifdef CONFIG_COMPAT
64 static long ntfs_compat_ioctl(struct file *filp, u32 cmd, unsigned long arg)
65 
66 {
67 	return ntfs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
68 }
69 #endif
70 
71 /*
72  * ntfs_getattr - inode_operations::getattr
73  */
74 int ntfs_getattr(struct mnt_idmap *idmap, const struct path *path,
75 		 struct kstat *stat, u32 request_mask, u32 flags)
76 {
77 	struct inode *inode = d_inode(path->dentry);
78 	struct ntfs_inode *ni = ntfs_i(inode);
79 
80 	if (is_compressed(ni))
81 		stat->attributes |= STATX_ATTR_COMPRESSED;
82 
83 	if (is_encrypted(ni))
84 		stat->attributes |= STATX_ATTR_ENCRYPTED;
85 
86 	stat->attributes_mask |= STATX_ATTR_COMPRESSED | STATX_ATTR_ENCRYPTED;
87 
88 	generic_fillattr(idmap, inode, stat);
89 
90 	stat->result_mask |= STATX_BTIME;
91 	stat->btime = ni->i_crtime;
92 	stat->blksize = ni->mi.sbi->cluster_size; /* 512, 1K, ..., 2M */
93 
94 	return 0;
95 }
96 
97 static int ntfs_extend_initialized_size(struct file *file,
98 					struct ntfs_inode *ni,
99 					const loff_t valid,
100 					const loff_t new_valid)
101 {
102 	struct inode *inode = &ni->vfs_inode;
103 	struct address_space *mapping = inode->i_mapping;
104 	struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;
105 	loff_t pos = valid;
106 	int err;
107 
108 	if (is_resident(ni)) {
109 		ni->i_valid = new_valid;
110 		return 0;
111 	}
112 
113 	WARN_ON(is_compressed(ni));
114 	WARN_ON(valid >= new_valid);
115 
116 	for (;;) {
117 		u32 zerofrom, len;
118 		struct page *page;
119 		u8 bits;
120 		CLST vcn, lcn, clen;
121 
122 		if (is_sparsed(ni)) {
123 			bits = sbi->cluster_bits;
124 			vcn = pos >> bits;
125 
126 			err = attr_data_get_block(ni, vcn, 1, &lcn, &clen, NULL,
127 						  false);
128 			if (err)
129 				goto out;
130 
131 			if (lcn == SPARSE_LCN) {
132 				pos = ((loff_t)clen + vcn) << bits;
133 				ni->i_valid = pos;
134 				goto next;
135 			}
136 		}
137 
138 		zerofrom = pos & (PAGE_SIZE - 1);
139 		len = PAGE_SIZE - zerofrom;
140 
141 		if (pos + len > new_valid)
142 			len = new_valid - pos;
143 
144 		err = ntfs_write_begin(file, mapping, pos, len, &page, NULL);
145 		if (err)
146 			goto out;
147 
148 		zero_user_segment(page, zerofrom, PAGE_SIZE);
149 
150 		/* This function in any case puts page. */
151 		err = ntfs_write_end(file, mapping, pos, len, len, page, NULL);
152 		if (err < 0)
153 			goto out;
154 		pos += len;
155 
156 next:
157 		if (pos >= new_valid)
158 			break;
159 
160 		balance_dirty_pages_ratelimited(mapping);
161 		cond_resched();
162 	}
163 
164 	return 0;
165 
166 out:
167 	ni->i_valid = valid;
168 	ntfs_inode_warn(inode, "failed to extend initialized size to %llx.",
169 			new_valid);
170 	return err;
171 }
172 
173 /*
174  * ntfs_zero_range - Helper function for punch_hole.
175  *
176  * It zeroes a range [vbo, vbo_to).
177  */
178 static int ntfs_zero_range(struct inode *inode, u64 vbo, u64 vbo_to)
179 {
180 	int err = 0;
181 	struct address_space *mapping = inode->i_mapping;
182 	u32 blocksize = 1 << inode->i_blkbits;
183 	pgoff_t idx = vbo >> PAGE_SHIFT;
184 	u32 from = vbo & (PAGE_SIZE - 1);
185 	pgoff_t idx_end = (vbo_to + PAGE_SIZE - 1) >> PAGE_SHIFT;
186 	loff_t page_off;
187 	struct buffer_head *head, *bh;
188 	u32 bh_next, bh_off, to;
189 	sector_t iblock;
190 	struct page *page;
191 
192 	for (; idx < idx_end; idx += 1, from = 0) {
193 		page_off = (loff_t)idx << PAGE_SHIFT;
194 		to = (page_off + PAGE_SIZE) > vbo_to ? (vbo_to - page_off) :
195 							     PAGE_SIZE;
196 		iblock = page_off >> inode->i_blkbits;
197 
198 		page = find_or_create_page(mapping, idx,
199 					   mapping_gfp_constraint(mapping,
200 								  ~__GFP_FS));
201 		if (!page)
202 			return -ENOMEM;
203 
204 		if (!page_has_buffers(page))
205 			create_empty_buffers(page, blocksize, 0);
206 
207 		bh = head = page_buffers(page);
208 		bh_off = 0;
209 		do {
210 			bh_next = bh_off + blocksize;
211 
212 			if (bh_next <= from || bh_off >= to)
213 				continue;
214 
215 			if (!buffer_mapped(bh)) {
216 				ntfs_get_block(inode, iblock, bh, 0);
217 				/* Unmapped? It's a hole - nothing to do. */
218 				if (!buffer_mapped(bh))
219 					continue;
220 			}
221 
222 			/* Ok, it's mapped. Make sure it's up-to-date. */
223 			if (PageUptodate(page))
224 				set_buffer_uptodate(bh);
225 
226 			if (!buffer_uptodate(bh)) {
227 				err = bh_read(bh, 0);
228 				if (err < 0) {
229 					unlock_page(page);
230 					put_page(page);
231 					goto out;
232 				}
233 			}
234 
235 			mark_buffer_dirty(bh);
236 
237 		} while (bh_off = bh_next, iblock += 1,
238 			 head != (bh = bh->b_this_page));
239 
240 		zero_user_segment(page, from, to);
241 
242 		unlock_page(page);
243 		put_page(page);
244 		cond_resched();
245 	}
246 out:
247 	mark_inode_dirty(inode);
248 	return err;
249 }
250 
251 /*
252  * ntfs_file_mmap - file_operations::mmap
253  */
254 static int ntfs_file_mmap(struct file *file, struct vm_area_struct *vma)
255 {
256 	struct address_space *mapping = file->f_mapping;
257 	struct inode *inode = mapping->host;
258 	struct ntfs_inode *ni = ntfs_i(inode);
259 	u64 from = ((u64)vma->vm_pgoff << PAGE_SHIFT);
260 	bool rw = vma->vm_flags & VM_WRITE;
261 	int err;
262 
263 	if (is_encrypted(ni)) {
264 		ntfs_inode_warn(inode, "mmap encrypted not supported");
265 		return -EOPNOTSUPP;
266 	}
267 
268 	if (is_dedup(ni)) {
269 		ntfs_inode_warn(inode, "mmap deduplicated not supported");
270 		return -EOPNOTSUPP;
271 	}
272 
273 	if (is_compressed(ni) && rw) {
274 		ntfs_inode_warn(inode, "mmap(write) compressed not supported");
275 		return -EOPNOTSUPP;
276 	}
277 
278 	if (rw) {
279 		u64 to = min_t(loff_t, i_size_read(inode),
280 			       from + vma->vm_end - vma->vm_start);
281 
282 		if (is_sparsed(ni)) {
283 			/* Allocate clusters for rw map. */
284 			struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;
285 			CLST lcn, len;
286 			CLST vcn = from >> sbi->cluster_bits;
287 			CLST end = bytes_to_cluster(sbi, to);
288 			bool new;
289 
290 			for (; vcn < end; vcn += len) {
291 				err = attr_data_get_block(ni, vcn, 1, &lcn,
292 							  &len, &new, true);
293 				if (err)
294 					goto out;
295 			}
296 		}
297 
298 		if (ni->i_valid < to) {
299 			if (!inode_trylock(inode)) {
300 				err = -EAGAIN;
301 				goto out;
302 			}
303 			err = ntfs_extend_initialized_size(file, ni,
304 							   ni->i_valid, to);
305 			inode_unlock(inode);
306 			if (err)
307 				goto out;
308 		}
309 	}
310 
311 	err = generic_file_mmap(file, vma);
312 out:
313 	return err;
314 }
315 
316 static int ntfs_extend(struct inode *inode, loff_t pos, size_t count,
317 		       struct file *file)
318 {
319 	struct ntfs_inode *ni = ntfs_i(inode);
320 	struct address_space *mapping = inode->i_mapping;
321 	loff_t end = pos + count;
322 	bool extend_init = file && pos > ni->i_valid;
323 	int err;
324 
325 	if (end <= inode->i_size && !extend_init)
326 		return 0;
327 
328 	/* Mark rw ntfs as dirty. It will be cleared at umount. */
329 	ntfs_set_state(ni->mi.sbi, NTFS_DIRTY_DIRTY);
330 
331 	if (end > inode->i_size) {
332 		err = ntfs_set_size(inode, end);
333 		if (err)
334 			goto out;
335 	}
336 
337 	if (extend_init && !is_compressed(ni)) {
338 		err = ntfs_extend_initialized_size(file, ni, ni->i_valid, pos);
339 		if (err)
340 			goto out;
341 	} else {
342 		err = 0;
343 	}
344 
345 	inode->i_ctime = inode->i_mtime = current_time(inode);
346 	mark_inode_dirty(inode);
347 
348 	if (IS_SYNC(inode)) {
349 		int err2;
350 
351 		err = filemap_fdatawrite_range(mapping, pos, end - 1);
352 		err2 = sync_mapping_buffers(mapping);
353 		if (!err)
354 			err = err2;
355 		err2 = write_inode_now(inode, 1);
356 		if (!err)
357 			err = err2;
358 		if (!err)
359 			err = filemap_fdatawait_range(mapping, pos, end - 1);
360 	}
361 
362 out:
363 	return err;
364 }
365 
366 static int ntfs_truncate(struct inode *inode, loff_t new_size)
367 {
368 	struct super_block *sb = inode->i_sb;
369 	struct ntfs_inode *ni = ntfs_i(inode);
370 	int err, dirty = 0;
371 	u64 new_valid;
372 
373 	if (!S_ISREG(inode->i_mode))
374 		return 0;
375 
376 	if (is_compressed(ni)) {
377 		if (ni->i_valid > new_size)
378 			ni->i_valid = new_size;
379 	} else {
380 		err = block_truncate_page(inode->i_mapping, new_size,
381 					  ntfs_get_block);
382 		if (err)
383 			return err;
384 	}
385 
386 	new_valid = ntfs_up_block(sb, min_t(u64, ni->i_valid, new_size));
387 
388 	truncate_setsize(inode, new_size);
389 
390 	ni_lock(ni);
391 
392 	down_write(&ni->file.run_lock);
393 	err = attr_set_size(ni, ATTR_DATA, NULL, 0, &ni->file.run, new_size,
394 			    &new_valid, ni->mi.sbi->options->prealloc, NULL);
395 	up_write(&ni->file.run_lock);
396 
397 	if (new_valid < ni->i_valid)
398 		ni->i_valid = new_valid;
399 
400 	ni_unlock(ni);
401 
402 	ni->std_fa |= FILE_ATTRIBUTE_ARCHIVE;
403 	inode->i_ctime = inode->i_mtime = current_time(inode);
404 	if (!IS_DIRSYNC(inode)) {
405 		dirty = 1;
406 	} else {
407 		err = ntfs_sync_inode(inode);
408 		if (err)
409 			return err;
410 	}
411 
412 	if (dirty)
413 		mark_inode_dirty(inode);
414 
415 	/*ntfs_flush_inodes(inode->i_sb, inode, NULL);*/
416 
417 	return 0;
418 }
419 
420 /*
421  * ntfs_fallocate
422  *
423  * Preallocate space for a file. This implements ntfs's fallocate file
424  * operation, which gets called from sys_fallocate system call. User
425  * space requests 'len' bytes at 'vbo'. If FALLOC_FL_KEEP_SIZE is set
426  * we just allocate clusters without zeroing them out. Otherwise we
427  * allocate and zero out clusters via an expanding truncate.
428  */
429 static long ntfs_fallocate(struct file *file, int mode, loff_t vbo, loff_t len)
430 {
431 	struct inode *inode = file->f_mapping->host;
432 	struct address_space *mapping = inode->i_mapping;
433 	struct super_block *sb = inode->i_sb;
434 	struct ntfs_sb_info *sbi = sb->s_fs_info;
435 	struct ntfs_inode *ni = ntfs_i(inode);
436 	loff_t end = vbo + len;
437 	loff_t vbo_down = round_down(vbo, max_t(unsigned long,
438 						sbi->cluster_size, PAGE_SIZE));
439 	bool is_supported_holes = is_sparsed(ni) || is_compressed(ni);
440 	loff_t i_size, new_size;
441 	bool map_locked;
442 	int err;
443 
444 	/* No support for dir. */
445 	if (!S_ISREG(inode->i_mode))
446 		return -EOPNOTSUPP;
447 
448 	/*
449 	 * vfs_fallocate checks all possible combinations of mode.
450 	 * Do additional checks here before ntfs_set_state(dirty).
451 	 */
452 	if (mode & FALLOC_FL_PUNCH_HOLE) {
453 		if (!is_supported_holes)
454 			return -EOPNOTSUPP;
455 	} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
456 	} else if (mode & FALLOC_FL_INSERT_RANGE) {
457 		if (!is_supported_holes)
458 			return -EOPNOTSUPP;
459 	} else if (mode &
460 		   ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
461 		     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)) {
462 		ntfs_inode_warn(inode, "fallocate(0x%x) is not supported",
463 				mode);
464 		return -EOPNOTSUPP;
465 	}
466 
467 	ntfs_set_state(sbi, NTFS_DIRTY_DIRTY);
468 
469 	inode_lock(inode);
470 	i_size = inode->i_size;
471 	new_size = max(end, i_size);
472 	map_locked = false;
473 
474 	if (WARN_ON(ni->ni_flags & NI_FLAG_COMPRESSED_MASK)) {
475 		/* Should never be here, see ntfs_file_open. */
476 		err = -EOPNOTSUPP;
477 		goto out;
478 	}
479 
480 	if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_COLLAPSE_RANGE |
481 		    FALLOC_FL_INSERT_RANGE)) {
482 		inode_dio_wait(inode);
483 		filemap_invalidate_lock(mapping);
484 		map_locked = true;
485 	}
486 
487 	if (mode & FALLOC_FL_PUNCH_HOLE) {
488 		u32 frame_size;
489 		loff_t mask, vbo_a, end_a, tmp;
490 
491 		err = filemap_write_and_wait_range(mapping, vbo_down,
492 						   LLONG_MAX);
493 		if (err)
494 			goto out;
495 
496 		truncate_pagecache(inode, vbo_down);
497 
498 		ni_lock(ni);
499 		err = attr_punch_hole(ni, vbo, len, &frame_size);
500 		ni_unlock(ni);
501 		if (err != E_NTFS_NOTALIGNED)
502 			goto out;
503 
504 		/* Process not aligned punch. */
505 		mask = frame_size - 1;
506 		vbo_a = (vbo + mask) & ~mask;
507 		end_a = end & ~mask;
508 
509 		tmp = min(vbo_a, end);
510 		if (tmp > vbo) {
511 			err = ntfs_zero_range(inode, vbo, tmp);
512 			if (err)
513 				goto out;
514 		}
515 
516 		if (vbo < end_a && end_a < end) {
517 			err = ntfs_zero_range(inode, end_a, end);
518 			if (err)
519 				goto out;
520 		}
521 
522 		/* Aligned punch_hole */
523 		if (end_a > vbo_a) {
524 			ni_lock(ni);
525 			err = attr_punch_hole(ni, vbo_a, end_a - vbo_a, NULL);
526 			ni_unlock(ni);
527 		}
528 	} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
529 		/*
530 		 * Write tail of the last page before removed range since
531 		 * it will get removed from the page cache below.
532 		 */
533 		err = filemap_write_and_wait_range(mapping, vbo_down, vbo);
534 		if (err)
535 			goto out;
536 
537 		/*
538 		 * Write data that will be shifted to preserve them
539 		 * when discarding page cache below.
540 		 */
541 		err = filemap_write_and_wait_range(mapping, end, LLONG_MAX);
542 		if (err)
543 			goto out;
544 
545 		truncate_pagecache(inode, vbo_down);
546 
547 		ni_lock(ni);
548 		err = attr_collapse_range(ni, vbo, len);
549 		ni_unlock(ni);
550 	} else if (mode & FALLOC_FL_INSERT_RANGE) {
551 		/* Check new size. */
552 		err = inode_newsize_ok(inode, new_size);
553 		if (err)
554 			goto out;
555 
556 		/* Write out all dirty pages. */
557 		err = filemap_write_and_wait_range(mapping, vbo_down,
558 						   LLONG_MAX);
559 		if (err)
560 			goto out;
561 		truncate_pagecache(inode, vbo_down);
562 
563 		ni_lock(ni);
564 		err = attr_insert_range(ni, vbo, len);
565 		ni_unlock(ni);
566 	} else {
567 		/* Check new size. */
568 		u8 cluster_bits = sbi->cluster_bits;
569 
570 		/* generic/213: expected -ENOSPC instead of -EFBIG. */
571 		if (!is_supported_holes) {
572 			loff_t to_alloc = new_size - inode_get_bytes(inode);
573 
574 			if (to_alloc > 0 &&
575 			    (to_alloc >> cluster_bits) >
576 				    wnd_zeroes(&sbi->used.bitmap)) {
577 				err = -ENOSPC;
578 				goto out;
579 			}
580 		}
581 
582 		err = inode_newsize_ok(inode, new_size);
583 		if (err)
584 			goto out;
585 
586 		if (new_size > i_size) {
587 			/*
588 			 * Allocate clusters, do not change 'valid' size.
589 			 */
590 			err = ntfs_set_size(inode, new_size);
591 			if (err)
592 				goto out;
593 		}
594 
595 		if (is_supported_holes) {
596 			CLST vcn = vbo >> cluster_bits;
597 			CLST cend = bytes_to_cluster(sbi, end);
598 			CLST cend_v = bytes_to_cluster(sbi, ni->i_valid);
599 			CLST lcn, clen;
600 			bool new;
601 
602 			if (cend_v > cend)
603 				cend_v = cend;
604 
605 			/*
606 			 * Allocate and zero new clusters.
607 			 * Zeroing these clusters may be too long.
608 			 */
609 			for (; vcn < cend_v; vcn += clen) {
610 				err = attr_data_get_block(ni, vcn, cend_v - vcn,
611 							  &lcn, &clen, &new,
612 							  true);
613 				if (err)
614 					goto out;
615 			}
616 			/*
617 			 * Allocate but not zero new clusters.
618 			 */
619 			for (; vcn < cend; vcn += clen) {
620 				err = attr_data_get_block(ni, vcn, cend - vcn,
621 							  &lcn, &clen, &new,
622 							  false);
623 				if (err)
624 					goto out;
625 			}
626 		}
627 
628 		if (mode & FALLOC_FL_KEEP_SIZE) {
629 			ni_lock(ni);
630 			/* True - Keep preallocated. */
631 			err = attr_set_size(ni, ATTR_DATA, NULL, 0,
632 					    &ni->file.run, i_size, &ni->i_valid,
633 					    true, NULL);
634 			ni_unlock(ni);
635 		} else if (new_size > i_size) {
636 			inode->i_size = new_size;
637 		}
638 	}
639 
640 out:
641 	if (map_locked)
642 		filemap_invalidate_unlock(mapping);
643 
644 	if (!err) {
645 		inode->i_ctime = inode->i_mtime = current_time(inode);
646 		mark_inode_dirty(inode);
647 	}
648 
649 	inode_unlock(inode);
650 	return err;
651 }
652 
653 /*
654  * ntfs3_setattr - inode_operations::setattr
655  */
656 int ntfs3_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
657 		  struct iattr *attr)
658 {
659 	struct inode *inode = d_inode(dentry);
660 	struct ntfs_inode *ni = ntfs_i(inode);
661 	u32 ia_valid = attr->ia_valid;
662 	umode_t mode = inode->i_mode;
663 	int err;
664 
665 	err = setattr_prepare(idmap, dentry, attr);
666 	if (err)
667 		goto out;
668 
669 	if (ia_valid & ATTR_SIZE) {
670 		loff_t newsize, oldsize;
671 
672 		if (WARN_ON(ni->ni_flags & NI_FLAG_COMPRESSED_MASK)) {
673 			/* Should never be here, see ntfs_file_open(). */
674 			err = -EOPNOTSUPP;
675 			goto out;
676 		}
677 		inode_dio_wait(inode);
678 		oldsize = inode->i_size;
679 		newsize = attr->ia_size;
680 
681 		if (newsize <= oldsize)
682 			err = ntfs_truncate(inode, newsize);
683 		else
684 			err = ntfs_extend(inode, newsize, 0, NULL);
685 
686 		if (err)
687 			goto out;
688 
689 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
690 		inode->i_size = newsize;
691 	}
692 
693 	setattr_copy(idmap, inode, attr);
694 
695 	if (mode != inode->i_mode) {
696 		err = ntfs_acl_chmod(idmap, dentry);
697 		if (err)
698 			goto out;
699 
700 		/* Linux 'w' -> Windows 'ro'. */
701 		if (0222 & inode->i_mode)
702 			ni->std_fa &= ~FILE_ATTRIBUTE_READONLY;
703 		else
704 			ni->std_fa |= FILE_ATTRIBUTE_READONLY;
705 	}
706 
707 	if (ia_valid & (ATTR_UID | ATTR_GID | ATTR_MODE))
708 		ntfs_save_wsl_perm(inode, NULL);
709 	mark_inode_dirty(inode);
710 out:
711 	return err;
712 }
713 
714 static ssize_t ntfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
715 {
716 	struct file *file = iocb->ki_filp;
717 	struct inode *inode = file->f_mapping->host;
718 	struct ntfs_inode *ni = ntfs_i(inode);
719 
720 	if (is_encrypted(ni)) {
721 		ntfs_inode_warn(inode, "encrypted i/o not supported");
722 		return -EOPNOTSUPP;
723 	}
724 
725 	if (is_compressed(ni) && (iocb->ki_flags & IOCB_DIRECT)) {
726 		ntfs_inode_warn(inode, "direct i/o + compressed not supported");
727 		return -EOPNOTSUPP;
728 	}
729 
730 #ifndef CONFIG_NTFS3_LZX_XPRESS
731 	if (ni->ni_flags & NI_FLAG_COMPRESSED_MASK) {
732 		ntfs_inode_warn(
733 			inode,
734 			"activate CONFIG_NTFS3_LZX_XPRESS to read external compressed files");
735 		return -EOPNOTSUPP;
736 	}
737 #endif
738 
739 	if (is_dedup(ni)) {
740 		ntfs_inode_warn(inode, "read deduplicated not supported");
741 		return -EOPNOTSUPP;
742 	}
743 
744 	return generic_file_read_iter(iocb, iter);
745 }
746 
747 /*
748  * ntfs_get_frame_pages
749  *
750  * Return: Array of locked pages.
751  */
752 static int ntfs_get_frame_pages(struct address_space *mapping, pgoff_t index,
753 				struct page **pages, u32 pages_per_frame,
754 				bool *frame_uptodate)
755 {
756 	gfp_t gfp_mask = mapping_gfp_mask(mapping);
757 	u32 npages;
758 
759 	*frame_uptodate = true;
760 
761 	for (npages = 0; npages < pages_per_frame; npages++, index++) {
762 		struct page *page;
763 
764 		page = find_or_create_page(mapping, index, gfp_mask);
765 		if (!page) {
766 			while (npages--) {
767 				page = pages[npages];
768 				unlock_page(page);
769 				put_page(page);
770 			}
771 
772 			return -ENOMEM;
773 		}
774 
775 		if (!PageUptodate(page))
776 			*frame_uptodate = false;
777 
778 		pages[npages] = page;
779 	}
780 
781 	return 0;
782 }
783 
784 /*
785  * ntfs_compress_write - Helper for ntfs_file_write_iter() (compressed files).
786  */
787 static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
788 {
789 	int err;
790 	struct file *file = iocb->ki_filp;
791 	size_t count = iov_iter_count(from);
792 	loff_t pos = iocb->ki_pos;
793 	struct inode *inode = file_inode(file);
794 	loff_t i_size = inode->i_size;
795 	struct address_space *mapping = inode->i_mapping;
796 	struct ntfs_inode *ni = ntfs_i(inode);
797 	u64 valid = ni->i_valid;
798 	struct ntfs_sb_info *sbi = ni->mi.sbi;
799 	struct page *page, **pages = NULL;
800 	size_t written = 0;
801 	u8 frame_bits = NTFS_LZNT_CUNIT + sbi->cluster_bits;
802 	u32 frame_size = 1u << frame_bits;
803 	u32 pages_per_frame = frame_size >> PAGE_SHIFT;
804 	u32 ip, off;
805 	CLST frame;
806 	u64 frame_vbo;
807 	pgoff_t index;
808 	bool frame_uptodate;
809 
810 	if (frame_size < PAGE_SIZE) {
811 		/*
812 		 * frame_size == 8K if cluster 512
813 		 * frame_size == 64K if cluster 4096
814 		 */
815 		ntfs_inode_warn(inode, "page size is bigger than frame size");
816 		return -EOPNOTSUPP;
817 	}
818 
819 	pages = kmalloc_array(pages_per_frame, sizeof(struct page *), GFP_NOFS);
820 	if (!pages)
821 		return -ENOMEM;
822 
823 	err = file_remove_privs(file);
824 	if (err)
825 		goto out;
826 
827 	err = file_update_time(file);
828 	if (err)
829 		goto out;
830 
831 	/* Zero range [valid : pos). */
832 	while (valid < pos) {
833 		CLST lcn, clen;
834 
835 		frame = valid >> frame_bits;
836 		frame_vbo = valid & ~(frame_size - 1);
837 		off = valid & (frame_size - 1);
838 
839 		err = attr_data_get_block(ni, frame << NTFS_LZNT_CUNIT, 1, &lcn,
840 					  &clen, NULL, false);
841 		if (err)
842 			goto out;
843 
844 		if (lcn == SPARSE_LCN) {
845 			ni->i_valid = valid =
846 				frame_vbo + ((u64)clen << sbi->cluster_bits);
847 			continue;
848 		}
849 
850 		/* Load full frame. */
851 		err = ntfs_get_frame_pages(mapping, frame_vbo >> PAGE_SHIFT,
852 					   pages, pages_per_frame,
853 					   &frame_uptodate);
854 		if (err)
855 			goto out;
856 
857 		if (!frame_uptodate && off) {
858 			err = ni_read_frame(ni, frame_vbo, pages,
859 					    pages_per_frame);
860 			if (err) {
861 				for (ip = 0; ip < pages_per_frame; ip++) {
862 					page = pages[ip];
863 					unlock_page(page);
864 					put_page(page);
865 				}
866 				goto out;
867 			}
868 		}
869 
870 		ip = off >> PAGE_SHIFT;
871 		off = offset_in_page(valid);
872 		for (; ip < pages_per_frame; ip++, off = 0) {
873 			page = pages[ip];
874 			zero_user_segment(page, off, PAGE_SIZE);
875 			flush_dcache_page(page);
876 			SetPageUptodate(page);
877 		}
878 
879 		ni_lock(ni);
880 		err = ni_write_frame(ni, pages, pages_per_frame);
881 		ni_unlock(ni);
882 
883 		for (ip = 0; ip < pages_per_frame; ip++) {
884 			page = pages[ip];
885 			SetPageUptodate(page);
886 			unlock_page(page);
887 			put_page(page);
888 		}
889 
890 		if (err)
891 			goto out;
892 
893 		ni->i_valid = valid = frame_vbo + frame_size;
894 	}
895 
896 	/* Copy user data [pos : pos + count). */
897 	while (count) {
898 		size_t copied, bytes;
899 
900 		off = pos & (frame_size - 1);
901 		bytes = frame_size - off;
902 		if (bytes > count)
903 			bytes = count;
904 
905 		frame_vbo = pos & ~(frame_size - 1);
906 		index = frame_vbo >> PAGE_SHIFT;
907 
908 		if (unlikely(fault_in_iov_iter_readable(from, bytes))) {
909 			err = -EFAULT;
910 			goto out;
911 		}
912 
913 		/* Load full frame. */
914 		err = ntfs_get_frame_pages(mapping, index, pages,
915 					   pages_per_frame, &frame_uptodate);
916 		if (err)
917 			goto out;
918 
919 		if (!frame_uptodate) {
920 			loff_t to = pos + bytes;
921 
922 			if (off || (to < i_size && (to & (frame_size - 1)))) {
923 				err = ni_read_frame(ni, frame_vbo, pages,
924 						    pages_per_frame);
925 				if (err) {
926 					for (ip = 0; ip < pages_per_frame;
927 					     ip++) {
928 						page = pages[ip];
929 						unlock_page(page);
930 						put_page(page);
931 					}
932 					goto out;
933 				}
934 			}
935 		}
936 
937 		WARN_ON(!bytes);
938 		copied = 0;
939 		ip = off >> PAGE_SHIFT;
940 		off = offset_in_page(pos);
941 
942 		/* Copy user data to pages. */
943 		for (;;) {
944 			size_t cp, tail = PAGE_SIZE - off;
945 
946 			page = pages[ip];
947 			cp = copy_page_from_iter_atomic(page, off,
948 							min(tail, bytes), from);
949 			flush_dcache_page(page);
950 
951 			copied += cp;
952 			bytes -= cp;
953 			if (!bytes || !cp)
954 				break;
955 
956 			if (cp < tail) {
957 				off += cp;
958 			} else {
959 				ip++;
960 				off = 0;
961 			}
962 		}
963 
964 		ni_lock(ni);
965 		err = ni_write_frame(ni, pages, pages_per_frame);
966 		ni_unlock(ni);
967 
968 		for (ip = 0; ip < pages_per_frame; ip++) {
969 			page = pages[ip];
970 			ClearPageDirty(page);
971 			SetPageUptodate(page);
972 			unlock_page(page);
973 			put_page(page);
974 		}
975 
976 		if (err)
977 			goto out;
978 
979 		/*
980 		 * We can loop for a long time in here. Be nice and allow
981 		 * us to schedule out to avoid softlocking if preempt
982 		 * is disabled.
983 		 */
984 		cond_resched();
985 
986 		pos += copied;
987 		written += copied;
988 
989 		count = iov_iter_count(from);
990 	}
991 
992 out:
993 	kfree(pages);
994 
995 	if (err < 0)
996 		return err;
997 
998 	iocb->ki_pos += written;
999 	if (iocb->ki_pos > ni->i_valid)
1000 		ni->i_valid = iocb->ki_pos;
1001 
1002 	return written;
1003 }
1004 
1005 /*
1006  * ntfs_file_write_iter - file_operations::write_iter
1007  */
1008 static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1009 {
1010 	struct file *file = iocb->ki_filp;
1011 	struct address_space *mapping = file->f_mapping;
1012 	struct inode *inode = mapping->host;
1013 	ssize_t ret;
1014 	struct ntfs_inode *ni = ntfs_i(inode);
1015 
1016 	if (is_encrypted(ni)) {
1017 		ntfs_inode_warn(inode, "encrypted i/o not supported");
1018 		return -EOPNOTSUPP;
1019 	}
1020 
1021 	if (is_compressed(ni) && (iocb->ki_flags & IOCB_DIRECT)) {
1022 		ntfs_inode_warn(inode, "direct i/o + compressed not supported");
1023 		return -EOPNOTSUPP;
1024 	}
1025 
1026 	if (is_dedup(ni)) {
1027 		ntfs_inode_warn(inode, "write into deduplicated not supported");
1028 		return -EOPNOTSUPP;
1029 	}
1030 
1031 	if (!inode_trylock(inode)) {
1032 		if (iocb->ki_flags & IOCB_NOWAIT)
1033 			return -EAGAIN;
1034 		inode_lock(inode);
1035 	}
1036 
1037 	ret = generic_write_checks(iocb, from);
1038 	if (ret <= 0)
1039 		goto out;
1040 
1041 	if (WARN_ON(ni->ni_flags & NI_FLAG_COMPRESSED_MASK)) {
1042 		/* Should never be here, see ntfs_file_open(). */
1043 		ret = -EOPNOTSUPP;
1044 		goto out;
1045 	}
1046 
1047 	ret = ntfs_extend(inode, iocb->ki_pos, ret, file);
1048 	if (ret)
1049 		goto out;
1050 
1051 	ret = is_compressed(ni) ? ntfs_compress_write(iocb, from) :
1052 					__generic_file_write_iter(iocb, from);
1053 
1054 out:
1055 	inode_unlock(inode);
1056 
1057 	if (ret > 0)
1058 		ret = generic_write_sync(iocb, ret);
1059 
1060 	return ret;
1061 }
1062 
1063 /*
1064  * ntfs_file_open - file_operations::open
1065  */
1066 int ntfs_file_open(struct inode *inode, struct file *file)
1067 {
1068 	struct ntfs_inode *ni = ntfs_i(inode);
1069 
1070 	if (unlikely((is_compressed(ni) || is_encrypted(ni)) &&
1071 		     (file->f_flags & O_DIRECT))) {
1072 		return -EOPNOTSUPP;
1073 	}
1074 
1075 	/* Decompress "external compressed" file if opened for rw. */
1076 	if ((ni->ni_flags & NI_FLAG_COMPRESSED_MASK) &&
1077 	    (file->f_flags & (O_WRONLY | O_RDWR | O_TRUNC))) {
1078 #ifdef CONFIG_NTFS3_LZX_XPRESS
1079 		int err = ni_decompress_file(ni);
1080 
1081 		if (err)
1082 			return err;
1083 #else
1084 		ntfs_inode_warn(
1085 			inode,
1086 			"activate CONFIG_NTFS3_LZX_XPRESS to write external compressed files");
1087 		return -EOPNOTSUPP;
1088 #endif
1089 	}
1090 
1091 	return generic_file_open(inode, file);
1092 }
1093 
1094 /*
1095  * ntfs_file_release - file_operations::release
1096  */
1097 static int ntfs_file_release(struct inode *inode, struct file *file)
1098 {
1099 	struct ntfs_inode *ni = ntfs_i(inode);
1100 	struct ntfs_sb_info *sbi = ni->mi.sbi;
1101 	int err = 0;
1102 
1103 	/* If we are last writer on the inode, drop the block reservation. */
1104 	if (sbi->options->prealloc &&
1105 	    ((file->f_mode & FMODE_WRITE) &&
1106 	     atomic_read(&inode->i_writecount) == 1)) {
1107 		ni_lock(ni);
1108 		down_write(&ni->file.run_lock);
1109 
1110 		err = attr_set_size(ni, ATTR_DATA, NULL, 0, &ni->file.run,
1111 				    inode->i_size, &ni->i_valid, false, NULL);
1112 
1113 		up_write(&ni->file.run_lock);
1114 		ni_unlock(ni);
1115 	}
1116 	return err;
1117 }
1118 
1119 /*
1120  * ntfs_fiemap - file_operations::fiemap
1121  */
1122 int ntfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1123 		__u64 start, __u64 len)
1124 {
1125 	int err;
1126 	struct ntfs_inode *ni = ntfs_i(inode);
1127 
1128 	err = fiemap_prep(inode, fieinfo, start, &len, ~FIEMAP_FLAG_XATTR);
1129 	if (err)
1130 		return err;
1131 
1132 	ni_lock(ni);
1133 
1134 	err = ni_fiemap(ni, fieinfo, start, len);
1135 
1136 	ni_unlock(ni);
1137 
1138 	return err;
1139 }
1140 
1141 // clang-format off
1142 const struct inode_operations ntfs_file_inode_operations = {
1143 	.getattr	= ntfs_getattr,
1144 	.setattr	= ntfs3_setattr,
1145 	.listxattr	= ntfs_listxattr,
1146 	.get_acl	= ntfs_get_acl,
1147 	.set_acl	= ntfs_set_acl,
1148 	.fiemap		= ntfs_fiemap,
1149 };
1150 
1151 const struct file_operations ntfs_file_operations = {
1152 	.llseek		= generic_file_llseek,
1153 	.read_iter	= ntfs_file_read_iter,
1154 	.write_iter	= ntfs_file_write_iter,
1155 	.unlocked_ioctl = ntfs_ioctl,
1156 #ifdef CONFIG_COMPAT
1157 	.compat_ioctl	= ntfs_compat_ioctl,
1158 #endif
1159 	.splice_read	= generic_file_splice_read,
1160 	.mmap		= ntfs_file_mmap,
1161 	.open		= ntfs_file_open,
1162 	.fsync		= generic_file_fsync,
1163 	.splice_write	= iter_file_splice_write,
1164 	.fallocate	= ntfs_fallocate,
1165 	.release	= ntfs_file_release,
1166 };
1167 // clang-format on
1168