cefa9835f275d9b062ae9b13765ea743edb53f64
[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         struct inode *inode = file_inode(vmf->vma->vm_file);
261         struct super_block *sb = inode->i_sb;
262         bool write = vmf->flags & FAULT_FLAG_WRITE;
263
264         if (write) {
265                 sb_start_pagefault(sb);
266                 file_update_time(vmf->vma->vm_file);
267         }
268         down_read(&EXT4_I(inode)->i_mmap_sem);
269         result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
270         up_read(&EXT4_I(inode)->i_mmap_sem);
271         if (write)
272                 sb_end_pagefault(sb);
273
274         return result;
275 }
276
277 static int ext4_dax_fault(struct vm_fault *vmf)
278 {
279         return ext4_dax_huge_fault(vmf, PE_SIZE_PTE);
280 }
281
282 /*
283  * Handle write fault for VM_MIXEDMAP mappings. Similarly to ext4_dax_fault()
284  * handler we check for races agaist truncate. Note that since we cycle through
285  * i_mmap_sem, we are sure that also any hole punching that began before we
286  * were called is finished by now and so if it included part of the file we
287  * are working on, our pte will get unmapped and the check for pte_same() in
288  * wp_pfn_shared() fails. Thus fault gets retried and things work out as
289  * desired.
290  */
291 static int ext4_dax_pfn_mkwrite(struct vm_fault *vmf)
292 {
293         struct inode *inode = file_inode(vmf->vma->vm_file);
294         struct super_block *sb = inode->i_sb;
295         loff_t size;
296         int ret;
297
298         sb_start_pagefault(sb);
299         file_update_time(vmf->vma->vm_file);
300         down_read(&EXT4_I(inode)->i_mmap_sem);
301         size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
302         if (vmf->pgoff >= size)
303                 ret = VM_FAULT_SIGBUS;
304         else
305                 ret = dax_pfn_mkwrite(vmf);
306         up_read(&EXT4_I(inode)->i_mmap_sem);
307         sb_end_pagefault(sb);
308
309         return ret;
310 }
311
312 static const struct vm_operations_struct ext4_dax_vm_ops = {
313         .fault          = ext4_dax_fault,
314         .huge_fault     = ext4_dax_huge_fault,
315         .page_mkwrite   = ext4_dax_fault,
316         .pfn_mkwrite    = ext4_dax_pfn_mkwrite,
317 };
318 #else
319 #define ext4_dax_vm_ops ext4_file_vm_ops
320 #endif
321
322 static const struct vm_operations_struct ext4_file_vm_ops = {
323         .fault          = ext4_filemap_fault,
324         .map_pages      = filemap_map_pages,
325         .page_mkwrite   = ext4_page_mkwrite,
326 };
327
328 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
329 {
330         struct inode *inode = file->f_mapping->host;
331
332         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
333                 return -EIO;
334
335         if (ext4_encrypted_inode(inode)) {
336                 int err = fscrypt_get_encryption_info(inode);
337                 if (err)
338                         return 0;
339                 if (!fscrypt_has_encryption_key(inode))
340                         return -ENOKEY;
341         }
342         file_accessed(file);
343         if (IS_DAX(file_inode(file))) {
344                 vma->vm_ops = &ext4_dax_vm_ops;
345                 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
346         } else {
347                 vma->vm_ops = &ext4_file_vm_ops;
348         }
349         return 0;
350 }
351
352 static int ext4_file_open(struct inode * inode, struct file * filp)
353 {
354         struct super_block *sb = inode->i_sb;
355         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
356         struct vfsmount *mnt = filp->f_path.mnt;
357         struct dentry *dir;
358         struct path path;
359         char buf[64], *cp;
360         int ret;
361
362         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
363                 return -EIO;
364
365         if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
366                      !(sb->s_flags & MS_RDONLY))) {
367                 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
368                 /*
369                  * Sample where the filesystem has been mounted and
370                  * store it in the superblock for sysadmin convenience
371                  * when trying to sort through large numbers of block
372                  * devices or filesystem images.
373                  */
374                 memset(buf, 0, sizeof(buf));
375                 path.mnt = mnt;
376                 path.dentry = mnt->mnt_root;
377                 cp = d_path(&path, buf, sizeof(buf));
378                 if (!IS_ERR(cp)) {
379                         handle_t *handle;
380                         int err;
381
382                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
383                         if (IS_ERR(handle))
384                                 return PTR_ERR(handle);
385                         BUFFER_TRACE(sbi->s_sbh, "get_write_access");
386                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
387                         if (err) {
388                                 ext4_journal_stop(handle);
389                                 return err;
390                         }
391                         strlcpy(sbi->s_es->s_last_mounted, cp,
392                                 sizeof(sbi->s_es->s_last_mounted));
393                         ext4_handle_dirty_super(handle, sb);
394                         ext4_journal_stop(handle);
395                 }
396         }
397         if (ext4_encrypted_inode(inode)) {
398                 ret = fscrypt_get_encryption_info(inode);
399                 if (ret)
400                         return -EACCES;
401                 if (!fscrypt_has_encryption_key(inode))
402                         return -ENOKEY;
403         }
404
405         dir = dget_parent(file_dentry(filp));
406         if (ext4_encrypted_inode(d_inode(dir)) &&
407                         !fscrypt_has_permitted_context(d_inode(dir), inode)) {
408                 ext4_warning(inode->i_sb,
409                              "Inconsistent encryption contexts: %lu/%lu",
410                              (unsigned long) d_inode(dir)->i_ino,
411                              (unsigned long) inode->i_ino);
412                 dput(dir);
413                 return -EPERM;
414         }
415         dput(dir);
416         /*
417          * Set up the jbd2_inode if we are opening the inode for
418          * writing and the journal is present
419          */
420         if (filp->f_mode & FMODE_WRITE) {
421                 ret = ext4_inode_attach_jinode(inode);
422                 if (ret < 0)
423                         return ret;
424         }
425         return dquot_file_open(inode, filp);
426 }
427
428 /*
429  * Here we use ext4_map_blocks() to get a block mapping for a extent-based
430  * file rather than ext4_ext_walk_space() because we can introduce
431  * SEEK_DATA/SEEK_HOLE for block-mapped and extent-mapped file at the same
432  * function.  When extent status tree has been fully implemented, it will
433  * track all extent status for a file and we can directly use it to
434  * retrieve the offset for SEEK_DATA/SEEK_HOLE.
435  */
436
437 /*
438  * When we retrieve the offset for SEEK_DATA/SEEK_HOLE, we would need to
439  * lookup page cache to check whether or not there has some data between
440  * [startoff, endoff] because, if this range contains an unwritten extent,
441  * we determine this extent as a data or a hole according to whether the
442  * page cache has data or not.
443  */
444 static int ext4_find_unwritten_pgoff(struct inode *inode,
445                                      int whence,
446                                      ext4_lblk_t end_blk,
447                                      loff_t *offset)
448 {
449         struct pagevec pvec;
450         unsigned int blkbits;
451         pgoff_t index;
452         pgoff_t end;
453         loff_t endoff;
454         loff_t startoff;
455         loff_t lastoff;
456         int found = 0;
457
458         blkbits = inode->i_sb->s_blocksize_bits;
459         startoff = *offset;
460         lastoff = startoff;
461         endoff = (loff_t)end_blk << blkbits;
462
463         index = startoff >> PAGE_SHIFT;
464         end = endoff >> PAGE_SHIFT;
465
466         pagevec_init(&pvec, 0);
467         do {
468                 int i, num;
469                 unsigned long nr_pages;
470
471                 num = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
472                 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
473                                           (pgoff_t)num);
474                 if (nr_pages == 0) {
475                         if (whence == SEEK_DATA)
476                                 break;
477
478                         BUG_ON(whence != SEEK_HOLE);
479                         /*
480                          * If this is the first time to go into the loop and
481                          * offset is not beyond the end offset, it will be a
482                          * hole at this offset
483                          */
484                         if (lastoff == startoff || lastoff < endoff)
485                                 found = 1;
486                         break;
487                 }
488
489                 /*
490                  * If this is the first time to go into the loop and
491                  * offset is smaller than the first page offset, it will be a
492                  * hole at this offset.
493                  */
494                 if (lastoff == startoff && whence == SEEK_HOLE &&
495                     lastoff < page_offset(pvec.pages[0])) {
496                         found = 1;
497                         break;
498                 }
499
500                 for (i = 0; i < nr_pages; i++) {
501                         struct page *page = pvec.pages[i];
502                         struct buffer_head *bh, *head;
503
504                         /*
505                          * If the current offset is not beyond the end of given
506                          * range, it will be a hole.
507                          */
508                         if (lastoff < endoff && whence == SEEK_HOLE &&
509                             page->index > end) {
510                                 found = 1;
511                                 *offset = lastoff;
512                                 goto out;
513                         }
514
515                         lock_page(page);
516
517                         if (unlikely(page->mapping != inode->i_mapping)) {
518                                 unlock_page(page);
519                                 continue;
520                         }
521
522                         if (!page_has_buffers(page)) {
523                                 unlock_page(page);
524                                 continue;
525                         }
526
527                         if (page_has_buffers(page)) {
528                                 lastoff = page_offset(page);
529                                 bh = head = page_buffers(page);
530                                 do {
531                                         if (buffer_uptodate(bh) ||
532                                             buffer_unwritten(bh)) {
533                                                 if (whence == SEEK_DATA)
534                                                         found = 1;
535                                         } else {
536                                                 if (whence == SEEK_HOLE)
537                                                         found = 1;
538                                         }
539                                         if (found) {
540                                                 *offset = max_t(loff_t,
541                                                         startoff, lastoff);
542                                                 unlock_page(page);
543                                                 goto out;
544                                         }
545                                         lastoff += bh->b_size;
546                                         bh = bh->b_this_page;
547                                 } while (bh != head);
548                         }
549
550                         lastoff = page_offset(page) + PAGE_SIZE;
551                         unlock_page(page);
552                 }
553
554                 /*
555                  * The no. of pages is less than our desired, that would be a
556                  * hole in there.
557                  */
558                 if (nr_pages < num && whence == SEEK_HOLE) {
559                         found = 1;
560                         *offset = lastoff;
561                         break;
562                 }
563
564                 index = pvec.pages[i - 1]->index + 1;
565                 pagevec_release(&pvec);
566         } while (index <= end);
567
568 out:
569         pagevec_release(&pvec);
570         return found;
571 }
572
573 /*
574  * ext4_seek_data() retrieves the offset for SEEK_DATA.
575  */
576 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
577 {
578         struct inode *inode = file->f_mapping->host;
579         struct extent_status es;
580         ext4_lblk_t start, last, end;
581         loff_t dataoff, isize;
582         int blkbits;
583         int ret;
584
585         inode_lock(inode);
586
587         isize = i_size_read(inode);
588         if (offset >= isize) {
589                 inode_unlock(inode);
590                 return -ENXIO;
591         }
592
593         blkbits = inode->i_sb->s_blocksize_bits;
594         start = offset >> blkbits;
595         last = start;
596         end = isize >> blkbits;
597         dataoff = offset;
598
599         do {
600                 ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
601                 if (ret <= 0) {
602                         /* No extent found -> no data */
603                         if (ret == 0)
604                                 ret = -ENXIO;
605                         inode_unlock(inode);
606                         return ret;
607                 }
608
609                 last = es.es_lblk;
610                 if (last != start)
611                         dataoff = (loff_t)last << blkbits;
612                 if (!ext4_es_is_unwritten(&es))
613                         break;
614
615                 /*
616                  * If there is a unwritten extent at this offset,
617                  * it will be as a data or a hole according to page
618                  * cache that has data or not.
619                  */
620                 if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
621                                               es.es_lblk + es.es_len, &dataoff))
622                         break;
623                 last += es.es_len;
624                 dataoff = (loff_t)last << blkbits;
625                 cond_resched();
626         } while (last <= end);
627
628         inode_unlock(inode);
629
630         if (dataoff > isize)
631                 return -ENXIO;
632
633         return vfs_setpos(file, dataoff, maxsize);
634 }
635
636 /*
637  * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
638  */
639 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
640 {
641         struct inode *inode = file->f_mapping->host;
642         struct extent_status es;
643         ext4_lblk_t start, last, end;
644         loff_t holeoff, isize;
645         int blkbits;
646         int ret;
647
648         inode_lock(inode);
649
650         isize = i_size_read(inode);
651         if (offset >= isize) {
652                 inode_unlock(inode);
653                 return -ENXIO;
654         }
655
656         blkbits = inode->i_sb->s_blocksize_bits;
657         start = offset >> blkbits;
658         last = start;
659         end = isize >> blkbits;
660         holeoff = offset;
661
662         do {
663                 ret = ext4_get_next_extent(inode, last, end - last + 1, &es);
664                 if (ret < 0) {
665                         inode_unlock(inode);
666                         return ret;
667                 }
668                 /* Found a hole? */
669                 if (ret == 0 || es.es_lblk > last) {
670                         if (last != start)
671                                 holeoff = (loff_t)last << blkbits;
672                         break;
673                 }
674                 /*
675                  * If there is a unwritten extent at this offset,
676                  * it will be as a data or a hole according to page
677                  * cache that has data or not.
678                  */
679                 if (ext4_es_is_unwritten(&es) &&
680                     ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
681                                               last + es.es_len, &holeoff))
682                         break;
683
684                 last += es.es_len;
685                 holeoff = (loff_t)last << blkbits;
686                 cond_resched();
687         } while (last <= end);
688
689         inode_unlock(inode);
690
691         if (holeoff > isize)
692                 holeoff = isize;
693
694         return vfs_setpos(file, holeoff, maxsize);
695 }
696
697 /*
698  * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
699  * by calling generic_file_llseek_size() with the appropriate maxbytes
700  * value for each.
701  */
702 loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
703 {
704         struct inode *inode = file->f_mapping->host;
705         loff_t maxbytes;
706
707         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
708                 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
709         else
710                 maxbytes = inode->i_sb->s_maxbytes;
711
712         switch (whence) {
713         case SEEK_SET:
714         case SEEK_CUR:
715         case SEEK_END:
716                 return generic_file_llseek_size(file, offset, whence,
717                                                 maxbytes, i_size_read(inode));
718         case SEEK_DATA:
719                 return ext4_seek_data(file, offset, maxbytes);
720         case SEEK_HOLE:
721                 return ext4_seek_hole(file, offset, maxbytes);
722         }
723
724         return -EINVAL;
725 }
726
727 const struct file_operations ext4_file_operations = {
728         .llseek         = ext4_llseek,
729         .read_iter      = ext4_file_read_iter,
730         .write_iter     = ext4_file_write_iter,
731         .unlocked_ioctl = ext4_ioctl,
732 #ifdef CONFIG_COMPAT
733         .compat_ioctl   = ext4_compat_ioctl,
734 #endif
735         .mmap           = ext4_file_mmap,
736         .open           = ext4_file_open,
737         .release        = ext4_release_file,
738         .fsync          = ext4_sync_file,
739         .get_unmapped_area = thp_get_unmapped_area,
740         .splice_read    = generic_file_splice_read,
741         .splice_write   = iter_file_splice_write,
742         .fallocate      = ext4_fallocate,
743 };
744
745 const struct inode_operations ext4_file_inode_operations = {
746         .setattr        = ext4_setattr,
747         .getattr        = ext4_file_getattr,
748         .listxattr      = ext4_listxattr,
749         .get_acl        = ext4_get_acl,
750         .set_acl        = ext4_set_acl,
751         .fiemap         = ext4_fiemap,
752 };
753