ext4: fix off-by-in in loop termination in ext4_find_unwritten_pgoff()
[sfrench/cifs-2.6.git] / fs / ext4 / file.c
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 #ifdef CONFIG_FS_DAX
35 static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
36 {
37         struct inode *inode = file_inode(iocb->ki_filp);
38         ssize_t ret;
39
40         inode_lock_shared(inode);
41         /*
42          * Recheck under inode lock - at this point we are sure it cannot
43          * change anymore
44          */
45         if (!IS_DAX(inode)) {
46                 inode_unlock_shared(inode);
47                 /* Fallback to buffered IO in case we cannot support DAX */
48                 return generic_file_read_iter(iocb, to);
49         }
50         ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops);
51         inode_unlock_shared(inode);
52
53         file_accessed(iocb->ki_filp);
54         return ret;
55 }
56 #endif
57
58 static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
59 {
60         if (unlikely(ext4_forced_shutdown(EXT4_SB(file_inode(iocb->ki_filp)->i_sb))))
61                 return -EIO;
62
63         if (!iov_iter_count(to))
64                 return 0; /* skip atime */
65
66 #ifdef CONFIG_FS_DAX
67         if (IS_DAX(file_inode(iocb->ki_filp)))
68                 return ext4_dax_read_iter(iocb, to);
69 #endif
70         return generic_file_read_iter(iocb, to);
71 }
72
73 /*
74  * Called when an inode is released. Note that this is different
75  * from ext4_file_open: open gets called at every open, but release
76  * gets called only when /all/ the files are closed.
77  */
78 static int ext4_release_file(struct inode *inode, struct file *filp)
79 {
80         if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
81                 ext4_alloc_da_blocks(inode);
82                 ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
83         }
84         /* if we are the last writer on the inode, drop the block reservation */
85         if ((filp->f_mode & FMODE_WRITE) &&
86                         (atomic_read(&inode->i_writecount) == 1) &&
87                         !EXT4_I(inode)->i_reserved_data_blocks)
88         {
89                 down_write(&EXT4_I(inode)->i_data_sem);
90                 ext4_discard_preallocations(inode);
91                 up_write(&EXT4_I(inode)->i_data_sem);
92         }
93         if (is_dx(inode) && filp->private_data)
94                 ext4_htree_free_dir_info(filp->private_data);
95
96         return 0;
97 }
98
99 static void ext4_unwritten_wait(struct inode *inode)
100 {
101         wait_queue_head_t *wq = ext4_ioend_wq(inode);
102
103         wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0));
104 }
105
106 /*
107  * This tests whether the IO in question is block-aligned or not.
108  * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
109  * are converted to written only after the IO is complete.  Until they are
110  * mapped, these blocks appear as holes, so dio_zero_block() will assume that
111  * it needs to zero out portions of the start and/or end block.  If 2 AIO
112  * threads are at work on the same unwritten block, they must be synchronized
113  * or one thread will zero the other's data, causing corruption.
114  */
115 static int
116 ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos)
117 {
118         struct super_block *sb = inode->i_sb;
119         int blockmask = sb->s_blocksize - 1;
120
121         if (pos >= i_size_read(inode))
122                 return 0;
123
124         if ((pos | iov_iter_alignment(from)) & blockmask)
125                 return 1;
126
127         return 0;
128 }
129
130 /* Is IO overwriting allocated and initialized blocks? */
131 static bool ext4_overwrite_io(struct inode *inode, loff_t pos, loff_t len)
132 {
133         struct ext4_map_blocks map;
134         unsigned int blkbits = inode->i_blkbits;
135         int err, blklen;
136
137         if (pos + len > i_size_read(inode))
138                 return false;
139
140         map.m_lblk = pos >> blkbits;
141         map.m_len = EXT4_MAX_BLOCKS(len, pos, blkbits);
142         blklen = map.m_len;
143
144         err = ext4_map_blocks(NULL, inode, &map, 0);
145         /*
146          * 'err==len' means that all of the blocks have been preallocated,
147          * regardless of whether they have been initialized or not. To exclude
148          * unwritten extents, we need to check m_flags.
149          */
150         return err == blklen && (map.m_flags & EXT4_MAP_MAPPED);
151 }
152
153 static ssize_t ext4_write_checks(struct kiocb *iocb, struct iov_iter *from)
154 {
155         struct inode *inode = file_inode(iocb->ki_filp);
156         ssize_t ret;
157
158         ret = generic_write_checks(iocb, from);
159         if (ret <= 0)
160                 return ret;
161         /*
162          * If we have encountered a bitmap-format file, the size limit
163          * is smaller than s_maxbytes, which is for extent-mapped files.
164          */
165         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
166                 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
167
168                 if (iocb->ki_pos >= sbi->s_bitmap_maxbytes)
169                         return -EFBIG;
170                 iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
171         }
172         return iov_iter_count(from);
173 }
174
175 #ifdef CONFIG_FS_DAX
176 static ssize_t
177 ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
178 {
179         struct inode *inode = file_inode(iocb->ki_filp);
180         ssize_t ret;
181
182         inode_lock(inode);
183         ret = ext4_write_checks(iocb, from);
184         if (ret <= 0)
185                 goto out;
186         ret = file_remove_privs(iocb->ki_filp);
187         if (ret)
188                 goto out;
189         ret = file_update_time(iocb->ki_filp);
190         if (ret)
191                 goto out;
192
193         ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
194 out:
195         inode_unlock(inode);
196         if (ret > 0)
197                 ret = generic_write_sync(iocb, ret);
198         return ret;
199 }
200 #endif
201
202 static ssize_t
203 ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
204 {
205         struct inode *inode = file_inode(iocb->ki_filp);
206         int o_direct = iocb->ki_flags & IOCB_DIRECT;
207         int unaligned_aio = 0;
208         int overwrite = 0;
209         ssize_t ret;
210
211         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
212                 return -EIO;
213
214 #ifdef CONFIG_FS_DAX
215         if (IS_DAX(inode))
216                 return ext4_dax_write_iter(iocb, from);
217 #endif
218
219         inode_lock(inode);
220         ret = ext4_write_checks(iocb, from);
221         if (ret <= 0)
222                 goto out;
223
224         /*
225          * Unaligned direct AIO must be serialized among each other as zeroing
226          * of partial blocks of two competing unaligned AIOs can result in data
227          * corruption.
228          */
229         if (o_direct && ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
230             !is_sync_kiocb(iocb) &&
231             ext4_unaligned_aio(inode, from, iocb->ki_pos)) {
232                 unaligned_aio = 1;
233                 ext4_unwritten_wait(inode);
234         }
235
236         iocb->private = &overwrite;
237         /* Check whether we do a DIO overwrite or not */
238         if (o_direct && ext4_should_dioread_nolock(inode) && !unaligned_aio &&
239             ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from)))
240                 overwrite = 1;
241
242         ret = __generic_file_write_iter(iocb, from);
243         inode_unlock(inode);
244
245         if (ret > 0)
246                 ret = generic_write_sync(iocb, ret);
247
248         return ret;
249
250 out:
251         inode_unlock(inode);
252         return ret;
253 }
254
255 #ifdef CONFIG_FS_DAX
256 static int ext4_dax_huge_fault(struct vm_fault *vmf,
257                 enum page_entry_size pe_size)
258 {
259         int result;
260         handle_t *handle = NULL;
261         struct inode *inode = file_inode(vmf->vma->vm_file);
262         struct super_block *sb = inode->i_sb;
263         bool write = vmf->flags & FAULT_FLAG_WRITE;
264
265         if (write) {
266                 sb_start_pagefault(sb);
267                 file_update_time(vmf->vma->vm_file);
268                 down_read(&EXT4_I(inode)->i_mmap_sem);
269                 handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
270                                                EXT4_DATA_TRANS_BLOCKS(sb));
271         } else {
272                 down_read(&EXT4_I(inode)->i_mmap_sem);
273         }
274         if (!IS_ERR(handle))
275                 result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
276         else
277                 result = VM_FAULT_SIGBUS;
278         if (write) {
279                 if (!IS_ERR(handle))
280                         ext4_journal_stop(handle);
281                 up_read(&EXT4_I(inode)->i_mmap_sem);
282                 sb_end_pagefault(sb);
283         } else {
284                 up_read(&EXT4_I(inode)->i_mmap_sem);
285         }
286
287         return result;
288 }
289
290 static int ext4_dax_fault(struct vm_fault *vmf)
291 {
292         return ext4_dax_huge_fault(vmf, PE_SIZE_PTE);
293 }
294
295 /*
296  * Handle write fault for VM_MIXEDMAP mappings. Similarly to ext4_dax_fault()
297  * handler we check for races agaist truncate. Note that since we cycle through
298  * i_mmap_sem, we are sure that also any hole punching that began before we
299  * were called is finished by now and so if it included part of the file we
300  * are working on, our pte will get unmapped and the check for pte_same() in
301  * wp_pfn_shared() fails. Thus fault gets retried and things work out as
302  * desired.
303  */
304 static int ext4_dax_pfn_mkwrite(struct vm_fault *vmf)
305 {
306         struct inode *inode = file_inode(vmf->vma->vm_file);
307         struct super_block *sb = inode->i_sb;
308         loff_t size;
309         int ret;
310
311         sb_start_pagefault(sb);
312         file_update_time(vmf->vma->vm_file);
313         down_read(&EXT4_I(inode)->i_mmap_sem);
314         size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
315         if (vmf->pgoff >= size)
316                 ret = VM_FAULT_SIGBUS;
317         else
318                 ret = dax_pfn_mkwrite(vmf);
319         up_read(&EXT4_I(inode)->i_mmap_sem);
320         sb_end_pagefault(sb);
321
322         return ret;
323 }
324
325 static const struct vm_operations_struct ext4_dax_vm_ops = {
326         .fault          = ext4_dax_fault,
327         .huge_fault     = ext4_dax_huge_fault,
328         .page_mkwrite   = ext4_dax_fault,
329         .pfn_mkwrite    = ext4_dax_pfn_mkwrite,
330 };
331 #else
332 #define ext4_dax_vm_ops ext4_file_vm_ops
333 #endif
334
335 static const struct vm_operations_struct ext4_file_vm_ops = {
336         .fault          = ext4_filemap_fault,
337         .map_pages      = filemap_map_pages,
338         .page_mkwrite   = ext4_page_mkwrite,
339 };
340
341 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
342 {
343         struct inode *inode = file->f_mapping->host;
344
345         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
346                 return -EIO;
347
348         if (ext4_encrypted_inode(inode)) {
349                 int err = fscrypt_get_encryption_info(inode);
350                 if (err)
351                         return 0;
352                 if (!fscrypt_has_encryption_key(inode))
353                         return -ENOKEY;
354         }
355         file_accessed(file);
356         if (IS_DAX(file_inode(file))) {
357                 vma->vm_ops = &ext4_dax_vm_ops;
358                 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
359         } else {
360                 vma->vm_ops = &ext4_file_vm_ops;
361         }
362         return 0;
363 }
364
365 static int ext4_file_open(struct inode * inode, struct file * filp)
366 {
367         struct super_block *sb = inode->i_sb;
368         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
369         struct vfsmount *mnt = filp->f_path.mnt;
370         struct dentry *dir;
371         struct path path;
372         char buf[64], *cp;
373         int ret;
374
375         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
376                 return -EIO;
377
378         if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
379                      !(sb->s_flags & MS_RDONLY))) {
380                 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
381                 /*
382                  * Sample where the filesystem has been mounted and
383                  * store it in the superblock for sysadmin convenience
384                  * when trying to sort through large numbers of block
385                  * devices or filesystem images.
386                  */
387                 memset(buf, 0, sizeof(buf));
388                 path.mnt = mnt;
389                 path.dentry = mnt->mnt_root;
390                 cp = d_path(&path, buf, sizeof(buf));
391                 if (!IS_ERR(cp)) {
392                         handle_t *handle;
393                         int err;
394
395                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
396                         if (IS_ERR(handle))
397                                 return PTR_ERR(handle);
398                         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
399                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
400                         if (err) {
401                                 ext4_journal_stop(handle);
402                                 return err;
403                         }
404                         strlcpy(sbi->s_es->s_last_mounted, cp,
405                                 sizeof(sbi->s_es->s_last_mounted));
406                         ext4_handle_dirty_super(handle, sb);
407                         ext4_journal_stop(handle);
408                 }
409         }
410         if (ext4_encrypted_inode(inode)) {
411                 ret = fscrypt_get_encryption_info(inode);
412                 if (ret)
413                         return -EACCES;
414                 if (!fscrypt_has_encryption_key(inode))
415                         return -ENOKEY;
416         }
417
418         dir = dget_parent(file_dentry(filp));
419         if (ext4_encrypted_inode(d_inode(dir)) &&
420                         !fscrypt_has_permitted_context(d_inode(dir), inode)) {
421                 ext4_warning(inode->i_sb,
422                              "Inconsistent encryption contexts: %lu/%lu",
423                              (unsigned long) d_inode(dir)->i_ino,
424                              (unsigned long) inode->i_ino);
425                 dput(dir);
426                 return -EPERM;
427         }
428         dput(dir);
429         /*
430          * Set up the jbd2_inode if we are opening the inode for
431          * writing and the journal is present
432          */
433         if (filp->f_mode & FMODE_WRITE) {
434                 ret = ext4_inode_attach_jinode(inode);
435                 if (ret < 0)
436                         return ret;
437         }
438         return dquot_file_open(inode, filp);
439 }
440
441 /*
442  * Here we use ext4_map_blocks() to get a block mapping for a extent-based
443  * file rather than ext4_ext_walk_space() because we can introduce
444  * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same
445  * function.  When extent status tree has been fully implemented, it will
446  * track all extent status for a file and we can directly use it to
447  * retrieve the offset for SEEK_DATA/SEEK_HOLE.
448  */
449
450 /*
451  * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to
452  * lookup page cache to check whether or not there has some data between
453  * [startoff, endoff] because, if this range contains an unwritten extent,
454  * we determine this extent as a data or a hole according to whether the
455  * page cache has data or not.
456  */
457 static int ext4_find_unwritten_pgoff(struct inode *inode,
458                                      int whence,
459                                      ext4_lblk_t end_blk,
460                                      loff_t *offset)
461 {
462         struct pagevec pvec;
463         unsigned int blkbits;
464         pgoff_t index;
465         pgoff_t end;
466         loff_t endoff;
467         loff_t startoff;
468         loff_t lastoff;
469         int found = 0;
470
471         blkbits = inode->i_sb->s_blocksize_bits;
472         startoff = *offset;
473         lastoff = startoff;
474         endoff = (loff_t)end_blk << blkbits;
475
476         index = startoff >> PAGE_SHIFT;
477         end = (endoff - 1) >> PAGE_SHIFT;
478
479         pagevec_init(&pvec, 0);
480         do {
481                 int i, num;
482                 unsigned long nr_pages;
483
484                 num = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
485                 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
486                                           (pgoff_t)num);
487                 if (nr_pages == 0)
488                         break;
489
490                 for (i = 0; i < nr_pages; i++) {
491                         struct page *page = pvec.pages[i];
492                         struct buffer_head *bh, *head;
493
494                         /*
495                          * If current offset is smaller than the page offset,
496                          * there is a hole at this offset.
497                          */
498                         if (whence == SEEK_HOLE && lastoff < endoff &&
499                             lastoff < page_offset(pvec.pages[i])) {
500                                 found = 1;
501                                 *offset = lastoff;
502                                 goto out;
503                         }
504
505                         if (page->index > end)
506                                 goto out;
507
508                         lock_page(page);
509
510                         if (unlikely(page->mapping != inode->i_mapping)) {
511                                 unlock_page(page);
512                                 continue;
513                         }
514
515                         if (!page_has_buffers(page)) {
516                                 unlock_page(page);
517                                 continue;
518                         }
519
520                         if (page_has_buffers(page)) {
521                                 lastoff = page_offset(page);
522                                 bh = head = page_buffers(page);
523                                 do {
524                                         if (buffer_uptodate(bh) ||
525                                             buffer_unwritten(bh)) {
526                                                 if (whence == SEEK_DATA)
527                                                         found = 1;
528                                         } else {
529                                                 if (whence == SEEK_HOLE)
530                                                         found = 1;
531                                         }
532                                         if (found) {
533                                                 *offset = max_t(loff_t,
534                                                         startoff, lastoff);
535                                                 unlock_page(page);
536                                                 goto out;
537                                         }
538                                         lastoff += bh->b_size;
539                                         bh = bh->b_this_page;
540                                 } while (bh != head);
541                         }
542
543                         lastoff = page_offset(page) + PAGE_SIZE;
544                         unlock_page(page);
545                 }
546
547                 /* The no. of pages is less than our desired, we are done. */
548                 if (nr_pages < num)
549                         break;
550
551                 index = pvec.pages[i - 1]->index + 1;
552                 pagevec_release(&pvec);
553         } while (index <= end);
554
555         if (whence == SEEK_HOLE && lastoff < endoff) {
556                 found = 1;
557                 *offset = lastoff;
558         }
559 out:
560         pagevec_release(&pvec);
561         return found;
562 }
563
564 /*
565  * ext4_seek_data() retrieves the offset for SEEK_DATA.
566  */
567 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
568 {
569         struct inode *inode = file->f_mapping->host;
570         struct extent_status es;
571         ext4_lblk_t start, last, end;
572         loff_t dataoff, isize;
573         int blkbits;
574         int ret;
575
576         inode_lock(inode);
577
578         isize = i_size_read(inode);
579         if (offset >= isize) {
580                 inode_unlock(inode);
581                 return -ENXIO;
582         }
583
584         blkbits = inode->i_sb->s_blocksize_bits;
585         start = offset >> blkbits;
586         last = start;
587         end = isize >> blkbits;
588         dataoff = offset;
589
590         do {
591                 ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
592                 if (ret <= 0) {
593                         /* No extent found -> no data */
594                         if (ret == 0)
595                                 ret = -ENXIO;
596                         inode_unlock(inode);
597                         return ret;
598                 }
599
600                 last = es.es_lblk;
601                 if (last != start)
602                         dataoff = (loff_t)last << blkbits;
603                 if (!ext4_es_is_unwritten(&es))
604                         break;
605
606                 /*
607                  * If there is a unwritten extent at this offset,
608                  * it will be as a data or a hole according to page
609                  * cache that has data or not.
610                  */
611                 if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
612                                               es.es_lblk + es.es_len, &dataoff))
613                         break;
614                 last += es.es_len;
615                 dataoff = (loff_t)last << blkbits;
616                 cond_resched();
617         } while (last <= end);
618
619         inode_unlock(inode);
620
621         if (dataoff > isize)
622                 return -ENXIO;
623
624         return vfs_setpos(file, dataoff, maxsize);
625 }
626
627 /*
628  * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
629  */
630 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
631 {
632         struct inode *inode = file->f_mapping->host;
633         struct extent_status es;
634         ext4_lblk_t start, last, end;
635         loff_t holeoff, isize;
636         int blkbits;
637         int ret;
638
639         inode_lock(inode);
640
641         isize = i_size_read(inode);
642         if (offset >= isize) {
643                 inode_unlock(inode);
644                 return -ENXIO;
645         }
646
647         blkbits = inode->i_sb->s_blocksize_bits;
648         start = offset >> blkbits;
649         last = start;
650         end = isize >> blkbits;
651         holeoff = offset;
652
653         do {
654                 ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
655                 if (ret < 0) {
656                         inode_unlock(inode);
657                         return ret;
658                 }
659                 /* Found a hole? */
660                 if (ret == 0 || es.es_lblk > last) {
661                         if (last != start)
662                                 holeoff = (loff_t)last << blkbits;
663                         break;
664                 }
665                 /*
666                  * If there is a unwritten extent at this offset,
667                  * it will be as a data or a hole according to page
668                  * cache that has data or not.
669                  */
670                 if (ext4_es_is_unwritten(&es) &&
671                     ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
672                                               last + es.es_len, &holeoff))
673                         break;
674
675                 last += es.es_len;
676                 holeoff = (loff_t)last << blkbits;
677                 cond_resched();
678         } while (last <= end);
679
680         inode_unlock(inode);
681
682         if (holeoff > isize)
683                 holeoff = isize;
684
685         return vfs_setpos(file, holeoff, maxsize);
686 }
687
688 /*
689  * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
690  * by calling generic_file_llseek_size() with the appropriate maxbytes
691  * value for each.
692  */
693 loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
694 {
695         struct inode *inode = file->f_mapping->host;
696         loff_t maxbytes;
697
698         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
699                 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
700         else
701                 maxbytes = inode->i_sb->s_maxbytes;
702
703         switch (whence) {
704         case SEEK_SET:
705         case SEEK_CUR:
706         case SEEK_END:
707                 return generic_file_llseek_size(file, offset, whence,
708                                                 maxbytes, i_size_read(inode));
709         case SEEK_DATA:
710                 return ext4_seek_data(file, offset, maxbytes);
711         case SEEK_HOLE:
712                 return ext4_seek_hole(file, offset, maxbytes);
713         }
714
715         return -EINVAL;
716 }
717
718 const struct file_operations ext4_file_operations = {
719         .llseek         = ext4_llseek,
720         .read_iter      = ext4_file_read_iter,
721         .write_iter     = ext4_file_write_iter,
722         .unlocked_ioctl = ext4_ioctl,
723 #ifdef CONFIG_COMPAT
724         .compat_ioctl   = ext4_compat_ioctl,
725 #endif
726         .mmap           = ext4_file_mmap,
727         .open           = ext4_file_open,
728         .release        = ext4_release_file,
729         .fsync          = ext4_sync_file,
730         .get_unmapped_area = thp_get_unmapped_area,
731         .splice_read    = generic_file_splice_read,
732         .splice_write   = iter_file_splice_write,
733         .fallocate      = ext4_fallocate,
734 };
735
736 const struct inode_operations ext4_file_inode_operations = {
737         .setattr        = ext4_setattr,
738         .getattr        = ext4_file_getattr,
739         .listxattr      = ext4_listxattr,
740         .get_acl        = ext4_get_acl,
741         .set_acl        = ext4_set_acl,
742         .fiemap         = ext4_fiemap,
743 };
744