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1 /*
2  *  linux/fs/ext4/file.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/file.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  ext4 fs regular file handling primitives
16  *
17  *  64-bit file support on 64-bit platforms by Jakub Jelinek
18  *	(jj@sunsite.ms.mff.cuni.cz)
19  */
20 
21 #include <linux/time.h>
22 #include <linux/fs.h>
23 #include <linux/mount.h>
24 #include <linux/path.h>
25 #include <linux/dax.h>
26 #include <linux/quotaops.h>
27 #include <linux/pagevec.h>
28 #include <linux/uio.h>
29 #include "ext4.h"
30 #include "ext4_jbd2.h"
31 #include "xattr.h"
32 #include "acl.h"
33 
34 /*
35  * Called when an inode is released. Note that this is different
36  * from ext4_file_open: open gets called at every open, but release
37  * gets called only when /all/ the files are closed.
38  */
ext4_release_file(struct inode * inode,struct file * filp)39 static int ext4_release_file(struct inode *inode, struct file *filp)
40 {
41 	if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
42 		ext4_alloc_da_blocks(inode);
43 		ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
44 	}
45 	/* if we are the last writer on the inode, drop the block reservation */
46 	if ((filp->f_mode & FMODE_WRITE) &&
47 			(atomic_read(&inode->i_writecount) == 1) &&
48 		        !EXT4_I(inode)->i_reserved_data_blocks)
49 	{
50 		down_write(&EXT4_I(inode)->i_data_sem);
51 		ext4_discard_preallocations(inode);
52 		up_write(&EXT4_I(inode)->i_data_sem);
53 	}
54 	if (is_dx(inode) && filp->private_data)
55 		ext4_htree_free_dir_info(filp->private_data);
56 
57 	return 0;
58 }
59 
ext4_unwritten_wait(struct inode * inode)60 static void ext4_unwritten_wait(struct inode *inode)
61 {
62 	wait_queue_head_t *wq = ext4_ioend_wq(inode);
63 
64 	wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0));
65 }
66 
67 /*
68  * This tests whether the IO in question is block-aligned or not.
69  * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
70  * are converted to written only after the IO is complete.  Until they are
71  * mapped, these blocks appear as holes, so dio_zero_block() will assume that
72  * it needs to zero out portions of the start and/or end block.  If 2 AIO
73  * threads are at work on the same unwritten block, they must be synchronized
74  * or one thread will zero the other's data, causing corruption.
75  */
76 static int
ext4_unaligned_aio(struct inode * inode,struct iov_iter * from,loff_t pos)77 ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos)
78 {
79 	struct super_block *sb = inode->i_sb;
80 	int blockmask = sb->s_blocksize - 1;
81 
82 	if (pos >= i_size_read(inode))
83 		return 0;
84 
85 	if ((pos | iov_iter_alignment(from)) & blockmask)
86 		return 1;
87 
88 	return 0;
89 }
90 
91 static ssize_t
ext4_file_write_iter(struct kiocb * iocb,struct iov_iter * from)92 ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
93 {
94 	struct inode *inode = file_inode(iocb->ki_filp);
95 	int o_direct = iocb->ki_flags & IOCB_DIRECT;
96 	int unaligned_aio = 0;
97 	int overwrite = 0;
98 	ssize_t ret;
99 
100 	inode_lock(inode);
101 	ret = generic_write_checks(iocb, from);
102 	if (ret <= 0)
103 		goto out;
104 
105 	/*
106 	 * Unaligned direct AIO must be serialized among each other as zeroing
107 	 * of partial blocks of two competing unaligned AIOs can result in data
108 	 * corruption.
109 	 */
110 	if (o_direct && ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
111 	    !is_sync_kiocb(iocb) &&
112 	    ext4_unaligned_aio(inode, from, iocb->ki_pos)) {
113 		unaligned_aio = 1;
114 		ext4_unwritten_wait(inode);
115 	}
116 
117 	/*
118 	 * If we have encountered a bitmap-format file, the size limit
119 	 * is smaller than s_maxbytes, which is for extent-mapped files.
120 	 */
121 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
122 		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
123 
124 		if (iocb->ki_pos >= sbi->s_bitmap_maxbytes) {
125 			ret = -EFBIG;
126 			goto out;
127 		}
128 		iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
129 	}
130 
131 	iocb->private = &overwrite;
132 	if (o_direct) {
133 		size_t length = iov_iter_count(from);
134 		loff_t pos = iocb->ki_pos;
135 
136 		/* check whether we do a DIO overwrite or not */
137 		if (ext4_should_dioread_nolock(inode) && !unaligned_aio &&
138 		    pos + length <= i_size_read(inode)) {
139 			struct ext4_map_blocks map;
140 			unsigned int blkbits = inode->i_blkbits;
141 			int err, len;
142 
143 			map.m_lblk = pos >> blkbits;
144 			map.m_len = EXT4_MAX_BLOCKS(length, pos, blkbits);
145 			len = map.m_len;
146 
147 			err = ext4_map_blocks(NULL, inode, &map, 0);
148 			/*
149 			 * 'err==len' means that all of blocks has
150 			 * been preallocated no matter they are
151 			 * initialized or not.  For excluding
152 			 * unwritten extents, we need to check
153 			 * m_flags.  There are two conditions that
154 			 * indicate for initialized extents.  1) If we
155 			 * hit extent cache, EXT4_MAP_MAPPED flag is
156 			 * returned; 2) If we do a real lookup,
157 			 * non-flags are returned.  So we should check
158 			 * these two conditions.
159 			 */
160 			if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
161 				overwrite = 1;
162 		}
163 	}
164 
165 	ret = __generic_file_write_iter(iocb, from);
166 	inode_unlock(inode);
167 
168 	if (ret > 0)
169 		ret = generic_write_sync(iocb, ret);
170 
171 	return ret;
172 
173 out:
174 	inode_unlock(inode);
175 	return ret;
176 }
177 
178 #ifdef CONFIG_FS_DAX
ext4_dax_fault(struct vm_area_struct * vma,struct vm_fault * vmf)179 static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
180 {
181 	int result;
182 	handle_t *handle = NULL;
183 	struct inode *inode = file_inode(vma->vm_file);
184 	struct super_block *sb = inode->i_sb;
185 	bool write = vmf->flags & FAULT_FLAG_WRITE;
186 
187 	if (write) {
188 		sb_start_pagefault(sb);
189 		file_update_time(vma->vm_file);
190 		down_read(&EXT4_I(inode)->i_mmap_sem);
191 		handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
192 						EXT4_DATA_TRANS_BLOCKS(sb));
193 	} else
194 		down_read(&EXT4_I(inode)->i_mmap_sem);
195 
196 	if (IS_ERR(handle))
197 		result = VM_FAULT_SIGBUS;
198 	else
199 		result = dax_fault(vma, vmf, ext4_dax_get_block);
200 
201 	if (write) {
202 		if (!IS_ERR(handle))
203 			ext4_journal_stop(handle);
204 		up_read(&EXT4_I(inode)->i_mmap_sem);
205 		sb_end_pagefault(sb);
206 	} else
207 		up_read(&EXT4_I(inode)->i_mmap_sem);
208 
209 	return result;
210 }
211 
ext4_dax_pmd_fault(struct vm_area_struct * vma,unsigned long addr,pmd_t * pmd,unsigned int flags)212 static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
213 						pmd_t *pmd, unsigned int flags)
214 {
215 	int result;
216 	handle_t *handle = NULL;
217 	struct inode *inode = file_inode(vma->vm_file);
218 	struct super_block *sb = inode->i_sb;
219 	bool write = flags & FAULT_FLAG_WRITE;
220 
221 	if (write) {
222 		sb_start_pagefault(sb);
223 		file_update_time(vma->vm_file);
224 		down_read(&EXT4_I(inode)->i_mmap_sem);
225 		handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
226 				ext4_chunk_trans_blocks(inode,
227 							PMD_SIZE / PAGE_SIZE));
228 	} else
229 		down_read(&EXT4_I(inode)->i_mmap_sem);
230 
231 	if (IS_ERR(handle))
232 		result = VM_FAULT_SIGBUS;
233 	else
234 		result = dax_pmd_fault(vma, addr, pmd, flags,
235 					 ext4_dax_get_block);
236 
237 	if (write) {
238 		if (!IS_ERR(handle))
239 			ext4_journal_stop(handle);
240 		up_read(&EXT4_I(inode)->i_mmap_sem);
241 		sb_end_pagefault(sb);
242 	} else
243 		up_read(&EXT4_I(inode)->i_mmap_sem);
244 
245 	return result;
246 }
247 
248 /*
249  * Handle write fault for VM_MIXEDMAP mappings. Similarly to ext4_dax_fault()
250  * handler we check for races agaist truncate. Note that since we cycle through
251  * i_mmap_sem, we are sure that also any hole punching that began before we
252  * were called is finished by now and so if it included part of the file we
253  * are working on, our pte will get unmapped and the check for pte_same() in
254  * wp_pfn_shared() fails. Thus fault gets retried and things work out as
255  * desired.
256  */
ext4_dax_pfn_mkwrite(struct vm_area_struct * vma,struct vm_fault * vmf)257 static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma,
258 				struct vm_fault *vmf)
259 {
260 	struct inode *inode = file_inode(vma->vm_file);
261 	struct super_block *sb = inode->i_sb;
262 	loff_t size;
263 	int ret;
264 
265 	sb_start_pagefault(sb);
266 	file_update_time(vma->vm_file);
267 	down_read(&EXT4_I(inode)->i_mmap_sem);
268 	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
269 	if (vmf->pgoff >= size)
270 		ret = VM_FAULT_SIGBUS;
271 	else
272 		ret = dax_pfn_mkwrite(vma, vmf);
273 	up_read(&EXT4_I(inode)->i_mmap_sem);
274 	sb_end_pagefault(sb);
275 
276 	return ret;
277 }
278 
279 static const struct vm_operations_struct ext4_dax_vm_ops = {
280 	.fault		= ext4_dax_fault,
281 	.pmd_fault	= ext4_dax_pmd_fault,
282 	.page_mkwrite	= ext4_dax_fault,
283 	.pfn_mkwrite	= ext4_dax_pfn_mkwrite,
284 };
285 #else
286 #define ext4_dax_vm_ops	ext4_file_vm_ops
287 #endif
288 
289 static const struct vm_operations_struct ext4_file_vm_ops = {
290 	.fault		= ext4_filemap_fault,
291 	.map_pages	= filemap_map_pages,
292 	.page_mkwrite   = ext4_page_mkwrite,
293 };
294 
ext4_file_mmap(struct file * file,struct vm_area_struct * vma)295 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
296 {
297 	struct inode *inode = file->f_mapping->host;
298 
299 	if (ext4_encrypted_inode(inode)) {
300 		int err = fscrypt_get_encryption_info(inode);
301 		if (err)
302 			return 0;
303 		if (!fscrypt_has_encryption_key(inode))
304 			return -ENOKEY;
305 	}
306 	file_accessed(file);
307 	if (IS_DAX(file_inode(file))) {
308 		vma->vm_ops = &ext4_dax_vm_ops;
309 		vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
310 	} else {
311 		vma->vm_ops = &ext4_file_vm_ops;
312 	}
313 	return 0;
314 }
315 
ext4_file_open(struct inode * inode,struct file * filp)316 static int ext4_file_open(struct inode * inode, struct file * filp)
317 {
318 	struct super_block *sb = inode->i_sb;
319 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
320 	struct vfsmount *mnt = filp->f_path.mnt;
321 	struct dentry *dir;
322 	struct path path;
323 	char buf[64], *cp;
324 	int ret;
325 
326 	if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
327 		     !(sb->s_flags & MS_RDONLY))) {
328 		sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
329 		/*
330 		 * Sample where the filesystem has been mounted and
331 		 * store it in the superblock for sysadmin convenience
332 		 * when trying to sort through large numbers of block
333 		 * devices or filesystem images.
334 		 */
335 		memset(buf, 0, sizeof(buf));
336 		path.mnt = mnt;
337 		path.dentry = mnt->mnt_root;
338 		cp = d_path(&path, buf, sizeof(buf));
339 		if (!IS_ERR(cp)) {
340 			handle_t *handle;
341 			int err;
342 
343 			handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
344 			if (IS_ERR(handle))
345 				return PTR_ERR(handle);
346 			BUFFER_TRACE(sbi->s_sbh, "get_write_access");
347 			err = ext4_journal_get_write_access(handle, sbi->s_sbh);
348 			if (err) {
349 				ext4_journal_stop(handle);
350 				return err;
351 			}
352 			strlcpy(sbi->s_es->s_last_mounted, cp,
353 				sizeof(sbi->s_es->s_last_mounted));
354 			ext4_handle_dirty_super(handle, sb);
355 			ext4_journal_stop(handle);
356 		}
357 	}
358 	if (ext4_encrypted_inode(inode)) {
359 		ret = fscrypt_get_encryption_info(inode);
360 		if (ret)
361 			return -EACCES;
362 		if (!fscrypt_has_encryption_key(inode))
363 			return -ENOKEY;
364 	}
365 
366 	dir = dget_parent(file_dentry(filp));
367 	if (ext4_encrypted_inode(d_inode(dir)) &&
368 			!fscrypt_has_permitted_context(d_inode(dir), inode)) {
369 		ext4_warning(inode->i_sb,
370 			     "Inconsistent encryption contexts: %lu/%lu",
371 			     (unsigned long) d_inode(dir)->i_ino,
372 			     (unsigned long) inode->i_ino);
373 		dput(dir);
374 		return -EPERM;
375 	}
376 	dput(dir);
377 	/*
378 	 * Set up the jbd2_inode if we are opening the inode for
379 	 * writing and the journal is present
380 	 */
381 	if (filp->f_mode & FMODE_WRITE) {
382 		ret = ext4_inode_attach_jinode(inode);
383 		if (ret < 0)
384 			return ret;
385 	}
386 	return dquot_file_open(inode, filp);
387 }
388 
389 /*
390  * Here we use ext4_map_blocks() to get a block mapping for a extent-based
391  * file rather than ext4_ext_walk_space() because we can introduce
392  * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same
393  * function.  When extent status tree has been fully implemented, it will
394  * track all extent status for a file and we can directly use it to
395  * retrieve the offset for SEEK_DATA/SEEK_HOLE.
396  */
397 
398 /*
399  * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to
400  * lookup page cache to check whether or not there has some data between
401  * [startoff, endoff] because, if this range contains an unwritten extent,
402  * we determine this extent as a data or a hole according to whether the
403  * page cache has data or not.
404  */
ext4_find_unwritten_pgoff(struct inode * inode,int whence,ext4_lblk_t end_blk,loff_t * offset)405 static int ext4_find_unwritten_pgoff(struct inode *inode,
406 				     int whence,
407 				     ext4_lblk_t end_blk,
408 				     loff_t *offset)
409 {
410 	struct pagevec pvec;
411 	unsigned int blkbits;
412 	pgoff_t index;
413 	pgoff_t end;
414 	loff_t endoff;
415 	loff_t startoff;
416 	loff_t lastoff;
417 	int found = 0;
418 
419 	blkbits = inode->i_sb->s_blocksize_bits;
420 	startoff = *offset;
421 	lastoff = startoff;
422 	endoff = (loff_t)end_blk << blkbits;
423 
424 	index = startoff >> PAGE_SHIFT;
425 	end = endoff >> PAGE_SHIFT;
426 
427 	pagevec_init(&pvec, 0);
428 	do {
429 		int i, num;
430 		unsigned long nr_pages;
431 
432 		num = min_t(pgoff_t, end - index, PAGEVEC_SIZE - 1) + 1;
433 		nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
434 					  (pgoff_t)num);
435 		if (nr_pages == 0)
436 			break;
437 
438 		for (i = 0; i < nr_pages; i++) {
439 			struct page *page = pvec.pages[i];
440 			struct buffer_head *bh, *head;
441 
442 			/*
443 			 * If current offset is smaller than the page offset,
444 			 * there is a hole at this offset.
445 			 */
446 			if (whence == SEEK_HOLE && lastoff < endoff &&
447 			    lastoff < page_offset(pvec.pages[i])) {
448 				found = 1;
449 				*offset = lastoff;
450 				goto out;
451 			}
452 
453 			if (page->index > end)
454 				goto out;
455 
456 			lock_page(page);
457 
458 			if (unlikely(page->mapping != inode->i_mapping)) {
459 				unlock_page(page);
460 				continue;
461 			}
462 
463 			if (!page_has_buffers(page)) {
464 				unlock_page(page);
465 				continue;
466 			}
467 
468 			if (page_has_buffers(page)) {
469 				lastoff = page_offset(page);
470 				bh = head = page_buffers(page);
471 				do {
472 					if (lastoff + bh->b_size <= startoff)
473 						goto next;
474 					if (buffer_uptodate(bh) ||
475 					    buffer_unwritten(bh)) {
476 						if (whence == SEEK_DATA)
477 							found = 1;
478 					} else {
479 						if (whence == SEEK_HOLE)
480 							found = 1;
481 					}
482 					if (found) {
483 						*offset = max_t(loff_t,
484 							startoff, lastoff);
485 						unlock_page(page);
486 						goto out;
487 					}
488 next:
489 					lastoff += bh->b_size;
490 					bh = bh->b_this_page;
491 				} while (bh != head);
492 			}
493 
494 			lastoff = page_offset(page) + PAGE_SIZE;
495 			unlock_page(page);
496 		}
497 
498 		/* The no. of pages is less than our desired, we are done. */
499 		if (nr_pages < num)
500 			break;
501 
502 		index = pvec.pages[i - 1]->index + 1;
503 		pagevec_release(&pvec);
504 	} while (index <= end);
505 
506 	if (whence == SEEK_HOLE && lastoff < endoff) {
507 		found = 1;
508 		*offset = lastoff;
509 	}
510 out:
511 	pagevec_release(&pvec);
512 	return found;
513 }
514 
515 /*
516  * ext4_seek_data() retrieves the offset for SEEK_DATA.
517  */
ext4_seek_data(struct file * file,loff_t offset,loff_t maxsize)518 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
519 {
520 	struct inode *inode = file->f_mapping->host;
521 	struct extent_status es;
522 	ext4_lblk_t start, last, end;
523 	loff_t dataoff, isize;
524 	int blkbits;
525 	int ret;
526 
527 	inode_lock(inode);
528 
529 	isize = i_size_read(inode);
530 	if (offset < 0 || offset >= isize) {
531 		inode_unlock(inode);
532 		return -ENXIO;
533 	}
534 
535 	blkbits = inode->i_sb->s_blocksize_bits;
536 	start = offset >> blkbits;
537 	last = start;
538 	end = isize >> blkbits;
539 	dataoff = offset;
540 
541 	do {
542 		ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
543 		if (ret <= 0) {
544 			/* No extent found -> no data */
545 			if (ret == 0)
546 				ret = -ENXIO;
547 			inode_unlock(inode);
548 			return ret;
549 		}
550 
551 		last = es.es_lblk;
552 		if (last != start)
553 			dataoff = (loff_t)last << blkbits;
554 		if (!ext4_es_is_unwritten(&es))
555 			break;
556 
557 		/*
558 		 * If there is a unwritten extent at this offset,
559 		 * it will be as a data or a hole according to page
560 		 * cache that has data or not.
561 		 */
562 		if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
563 					      es.es_lblk + es.es_len, &dataoff))
564 			break;
565 		last += es.es_len;
566 		dataoff = (loff_t)last << blkbits;
567 		cond_resched();
568 	} while (last <= end);
569 
570 	inode_unlock(inode);
571 
572 	if (dataoff > isize)
573 		return -ENXIO;
574 
575 	return vfs_setpos(file, dataoff, maxsize);
576 }
577 
578 /*
579  * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
580  */
ext4_seek_hole(struct file * file,loff_t offset,loff_t maxsize)581 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
582 {
583 	struct inode *inode = file->f_mapping->host;
584 	struct extent_status es;
585 	ext4_lblk_t start, last, end;
586 	loff_t holeoff, isize;
587 	int blkbits;
588 	int ret;
589 
590 	inode_lock(inode);
591 
592 	isize = i_size_read(inode);
593 	if (offset < 0 || offset >= isize) {
594 		inode_unlock(inode);
595 		return -ENXIO;
596 	}
597 
598 	blkbits = inode->i_sb->s_blocksize_bits;
599 	start = offset >> blkbits;
600 	last = start;
601 	end = isize >> blkbits;
602 	holeoff = offset;
603 
604 	do {
605 		ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
606 		if (ret < 0) {
607 			inode_unlock(inode);
608 			return ret;
609 		}
610 		/* Found a hole? */
611 		if (ret == 0 || es.es_lblk > last) {
612 			if (last != start)
613 				holeoff = (loff_t)last << blkbits;
614 			break;
615 		}
616 		/*
617 		 * If there is a unwritten extent at this offset,
618 		 * it will be as a data or a hole according to page
619 		 * cache that has data or not.
620 		 */
621 		if (ext4_es_is_unwritten(&es) &&
622 		    ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
623 					      last + es.es_len, &holeoff))
624 			break;
625 
626 		last += es.es_len;
627 		holeoff = (loff_t)last << blkbits;
628 		cond_resched();
629 	} while (last <= end);
630 
631 	inode_unlock(inode);
632 
633 	if (holeoff > isize)
634 		holeoff = isize;
635 
636 	return vfs_setpos(file, holeoff, maxsize);
637 }
638 
639 /*
640  * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
641  * by calling generic_file_llseek_size() with the appropriate maxbytes
642  * value for each.
643  */
ext4_llseek(struct file * file,loff_t offset,int whence)644 loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
645 {
646 	struct inode *inode = file->f_mapping->host;
647 	loff_t maxbytes;
648 
649 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
650 		maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
651 	else
652 		maxbytes = inode->i_sb->s_maxbytes;
653 
654 	switch (whence) {
655 	case SEEK_SET:
656 	case SEEK_CUR:
657 	case SEEK_END:
658 		return generic_file_llseek_size(file, offset, whence,
659 						maxbytes, i_size_read(inode));
660 	case SEEK_DATA:
661 		return ext4_seek_data(file, offset, maxbytes);
662 	case SEEK_HOLE:
663 		return ext4_seek_hole(file, offset, maxbytes);
664 	}
665 
666 	return -EINVAL;
667 }
668 
669 const struct file_operations ext4_file_operations = {
670 	.llseek		= ext4_llseek,
671 	.read_iter	= generic_file_read_iter,
672 	.write_iter	= ext4_file_write_iter,
673 	.unlocked_ioctl = ext4_ioctl,
674 #ifdef CONFIG_COMPAT
675 	.compat_ioctl	= ext4_compat_ioctl,
676 #endif
677 	.mmap		= ext4_file_mmap,
678 	.open		= ext4_file_open,
679 	.release	= ext4_release_file,
680 	.fsync		= ext4_sync_file,
681 	.get_unmapped_area = thp_get_unmapped_area,
682 	.splice_read	= generic_file_splice_read,
683 	.splice_write	= iter_file_splice_write,
684 	.fallocate	= ext4_fallocate,
685 };
686 
687 const struct inode_operations ext4_file_inode_operations = {
688 	.setattr	= ext4_setattr,
689 	.getattr	= ext4_getattr,
690 	.listxattr	= ext4_listxattr,
691 	.get_acl	= ext4_get_acl,
692 	.set_acl	= ext4_set_acl,
693 	.fiemap		= ext4_fiemap,
694 };
695 
696