xref: /kernel/linux/linux-5.10/fs/overlayfs/file.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2017 Red Hat, Inc.
4 */
5
6#include <linux/cred.h>
7#include <linux/file.h>
8#include <linux/mount.h>
9#include <linux/xattr.h>
10#include <linux/uio.h>
11#include <linux/uaccess.h>
12#include <linux/splice.h>
13#include <linux/security.h>
14#include <linux/mm.h>
15#include <linux/fs.h>
16#include "overlayfs.h"
17
18struct ovl_aio_req {
19	struct kiocb iocb;
20	refcount_t ref;
21	struct kiocb *orig_iocb;
22};
23
24static struct kmem_cache *ovl_aio_request_cachep;
25
26static char ovl_whatisit(struct inode *inode, struct inode *realinode)
27{
28	if (realinode != ovl_inode_upper(inode))
29		return 'l';
30	if (ovl_has_upperdata(inode))
31		return 'u';
32	else
33		return 'm';
34}
35
36/* No atime modificaton nor notify on underlying */
37#define OVL_OPEN_FLAGS (O_NOATIME | FMODE_NONOTIFY)
38
39static struct file *ovl_open_realfile(const struct file *file,
40				      struct inode *realinode)
41{
42	struct inode *inode = file_inode(file);
43	struct file *realfile;
44	const struct cred *old_cred;
45	int flags = file->f_flags | OVL_OPEN_FLAGS;
46	int acc_mode = ACC_MODE(flags);
47	int err;
48
49	if (flags & O_APPEND)
50		acc_mode |= MAY_APPEND;
51
52	old_cred = ovl_override_creds(inode->i_sb);
53	err = inode_permission(realinode, MAY_OPEN | acc_mode);
54	if (err) {
55		realfile = ERR_PTR(err);
56	} else if (!inode_owner_or_capable(realinode)) {
57		realfile = ERR_PTR(-EPERM);
58	} else {
59		realfile = open_with_fake_path(&file->f_path, flags, realinode,
60					       current_cred());
61	}
62	revert_creds(old_cred);
63
64	pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n",
65		 file, file, ovl_whatisit(inode, realinode), file->f_flags,
66		 realfile, IS_ERR(realfile) ? 0 : realfile->f_flags);
67
68	return realfile;
69}
70
71#define OVL_SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT)
72
73static int ovl_change_flags(struct file *file, unsigned int flags)
74{
75	struct inode *inode = file_inode(file);
76	int err;
77
78	flags |= OVL_OPEN_FLAGS;
79
80	/* If some flag changed that cannot be changed then something's amiss */
81	if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK))
82		return -EIO;
83
84	flags &= OVL_SETFL_MASK;
85
86	if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode))
87		return -EPERM;
88
89	if (flags & O_DIRECT) {
90		if (!file->f_mapping->a_ops ||
91		    !file->f_mapping->a_ops->direct_IO)
92			return -EINVAL;
93	}
94
95	if (file->f_op->check_flags) {
96		err = file->f_op->check_flags(flags);
97		if (err)
98			return err;
99	}
100
101	spin_lock(&file->f_lock);
102	file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags;
103	spin_unlock(&file->f_lock);
104
105	return 0;
106}
107
108static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
109			       bool allow_meta)
110{
111	struct inode *inode = file_inode(file);
112	struct inode *realinode;
113
114	real->flags = 0;
115	real->file = file->private_data;
116
117	if (allow_meta)
118		realinode = ovl_inode_real(inode);
119	else
120		realinode = ovl_inode_realdata(inode);
121
122	/* Has it been copied up since we'd opened it? */
123	if (unlikely(file_inode(real->file) != realinode)) {
124		real->flags = FDPUT_FPUT;
125		real->file = ovl_open_realfile(file, realinode);
126
127		return PTR_ERR_OR_ZERO(real->file);
128	}
129
130	/* Did the flags change since open? */
131	if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS))
132		return ovl_change_flags(real->file, file->f_flags);
133
134	return 0;
135}
136
137static int ovl_real_fdget(const struct file *file, struct fd *real)
138{
139	if (d_is_dir(file_dentry(file))) {
140		real->flags = 0;
141		real->file = ovl_dir_real_file(file, false);
142
143		return PTR_ERR_OR_ZERO(real->file);
144	}
145
146	return ovl_real_fdget_meta(file, real, false);
147}
148
149static int ovl_open(struct inode *inode, struct file *file)
150{
151	struct file *realfile;
152	int err;
153
154	err = ovl_maybe_copy_up(file_dentry(file), file->f_flags);
155	if (err)
156		return err;
157
158	/* No longer need these flags, so don't pass them on to underlying fs */
159	file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
160
161	realfile = ovl_open_realfile(file, ovl_inode_realdata(inode));
162	if (IS_ERR(realfile))
163		return PTR_ERR(realfile);
164
165	file->private_data = realfile;
166
167	return 0;
168}
169
170static int ovl_release(struct inode *inode, struct file *file)
171{
172	fput(file->private_data);
173
174	return 0;
175}
176
177static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
178{
179	struct inode *inode = file_inode(file);
180	struct fd real;
181	const struct cred *old_cred;
182	loff_t ret;
183
184	/*
185	 * The two special cases below do not need to involve real fs,
186	 * so we can optimizing concurrent callers.
187	 */
188	if (offset == 0) {
189		if (whence == SEEK_CUR)
190			return file->f_pos;
191
192		if (whence == SEEK_SET)
193			return vfs_setpos(file, 0, 0);
194	}
195
196	ret = ovl_real_fdget(file, &real);
197	if (ret)
198		return ret;
199
200	/*
201	 * Overlay file f_pos is the master copy that is preserved
202	 * through copy up and modified on read/write, but only real
203	 * fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose
204	 * limitations that are more strict than ->s_maxbytes for specific
205	 * files, so we use the real file to perform seeks.
206	 */
207	ovl_inode_lock(inode);
208	real.file->f_pos = file->f_pos;
209
210	old_cred = ovl_override_creds(inode->i_sb);
211	ret = vfs_llseek(real.file, offset, whence);
212	revert_creds(old_cred);
213
214	file->f_pos = real.file->f_pos;
215	ovl_inode_unlock(inode);
216
217	fdput(real);
218
219	return ret;
220}
221
222static void ovl_file_accessed(struct file *file)
223{
224	struct inode *inode, *upperinode;
225
226	if (file->f_flags & O_NOATIME)
227		return;
228
229	inode = file_inode(file);
230	upperinode = ovl_inode_upper(inode);
231
232	if (!upperinode)
233		return;
234
235	if ((!timespec64_equal(&inode->i_mtime, &upperinode->i_mtime) ||
236	     !timespec64_equal(&inode->i_ctime, &upperinode->i_ctime))) {
237		inode->i_mtime = upperinode->i_mtime;
238		inode->i_ctime = upperinode->i_ctime;
239	}
240
241	touch_atime(&file->f_path);
242}
243
244static rwf_t ovl_iocb_to_rwf(int ifl)
245{
246	rwf_t flags = 0;
247
248	if (ifl & IOCB_NOWAIT)
249		flags |= RWF_NOWAIT;
250	if (ifl & IOCB_HIPRI)
251		flags |= RWF_HIPRI;
252	if (ifl & IOCB_DSYNC)
253		flags |= RWF_DSYNC;
254	if (ifl & IOCB_SYNC)
255		flags |= RWF_SYNC;
256
257	return flags;
258}
259
260static inline void ovl_aio_put(struct ovl_aio_req *aio_req)
261{
262	if (refcount_dec_and_test(&aio_req->ref)) {
263		fput(aio_req->iocb.ki_filp);
264		kmem_cache_free(ovl_aio_request_cachep, aio_req);
265	}
266}
267
268static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req)
269{
270	struct kiocb *iocb = &aio_req->iocb;
271	struct kiocb *orig_iocb = aio_req->orig_iocb;
272
273	if (iocb->ki_flags & IOCB_WRITE) {
274		struct inode *inode = file_inode(orig_iocb->ki_filp);
275
276		/* Actually acquired in ovl_write_iter() */
277		__sb_writers_acquired(file_inode(iocb->ki_filp)->i_sb,
278				      SB_FREEZE_WRITE);
279		file_end_write(iocb->ki_filp);
280		ovl_copyattr(ovl_inode_real(inode), inode);
281	}
282
283	orig_iocb->ki_pos = iocb->ki_pos;
284	ovl_aio_put(aio_req);
285}
286
287static void ovl_aio_rw_complete(struct kiocb *iocb, long res, long res2)
288{
289	struct ovl_aio_req *aio_req = container_of(iocb,
290						   struct ovl_aio_req, iocb);
291	struct kiocb *orig_iocb = aio_req->orig_iocb;
292
293	ovl_aio_cleanup_handler(aio_req);
294	orig_iocb->ki_complete(orig_iocb, res, res2);
295}
296
297static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
298{
299	struct file *file = iocb->ki_filp;
300	struct fd real;
301	const struct cred *old_cred;
302	ssize_t ret;
303
304	if (!iov_iter_count(iter))
305		return 0;
306
307	ret = ovl_real_fdget(file, &real);
308	if (ret)
309		return ret;
310
311	ret = -EINVAL;
312	if (iocb->ki_flags & IOCB_DIRECT &&
313	    (!real.file->f_mapping->a_ops ||
314	     !real.file->f_mapping->a_ops->direct_IO))
315		goto out_fdput;
316
317	old_cred = ovl_override_creds(file_inode(file)->i_sb);
318	if (is_sync_kiocb(iocb)) {
319		ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
320				    ovl_iocb_to_rwf(iocb->ki_flags));
321	} else {
322		struct ovl_aio_req *aio_req;
323
324		ret = -ENOMEM;
325		aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
326		if (!aio_req)
327			goto out;
328
329		real.flags = 0;
330		aio_req->orig_iocb = iocb;
331		kiocb_clone(&aio_req->iocb, iocb, get_file(real.file));
332		aio_req->iocb.ki_complete = ovl_aio_rw_complete;
333		refcount_set(&aio_req->ref, 2);
334		ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter);
335		ovl_aio_put(aio_req);
336		if (ret != -EIOCBQUEUED)
337			ovl_aio_cleanup_handler(aio_req);
338	}
339out:
340	revert_creds(old_cred);
341	ovl_file_accessed(file);
342out_fdput:
343	fdput(real);
344
345	return ret;
346}
347
348static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
349{
350	struct file *file = iocb->ki_filp;
351	struct inode *inode = file_inode(file);
352	struct fd real;
353	const struct cred *old_cred;
354	ssize_t ret;
355	int ifl = iocb->ki_flags;
356
357	if (!iov_iter_count(iter))
358		return 0;
359
360	inode_lock(inode);
361	/* Update mode */
362	ovl_copyattr(ovl_inode_real(inode), inode);
363	ret = file_remove_privs(file);
364	if (ret)
365		goto out_unlock;
366
367	ret = ovl_real_fdget(file, &real);
368	if (ret)
369		goto out_unlock;
370
371	ret = -EINVAL;
372	if (iocb->ki_flags & IOCB_DIRECT &&
373	    (!real.file->f_mapping->a_ops ||
374	     !real.file->f_mapping->a_ops->direct_IO))
375		goto out_fdput;
376
377	if (!ovl_should_sync(OVL_FS(inode->i_sb)))
378		ifl &= ~(IOCB_DSYNC | IOCB_SYNC);
379
380	old_cred = ovl_override_creds(file_inode(file)->i_sb);
381	if (is_sync_kiocb(iocb)) {
382		file_start_write(real.file);
383		ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
384				     ovl_iocb_to_rwf(ifl));
385		file_end_write(real.file);
386		/* Update size */
387		ovl_copyattr(ovl_inode_real(inode), inode);
388	} else {
389		struct ovl_aio_req *aio_req;
390
391		ret = -ENOMEM;
392		aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
393		if (!aio_req)
394			goto out;
395
396		file_start_write(real.file);
397		/* Pacify lockdep, same trick as done in aio_write() */
398		__sb_writers_release(file_inode(real.file)->i_sb,
399				     SB_FREEZE_WRITE);
400		real.flags = 0;
401		aio_req->orig_iocb = iocb;
402		kiocb_clone(&aio_req->iocb, iocb, get_file(real.file));
403		aio_req->iocb.ki_flags = ifl;
404		aio_req->iocb.ki_complete = ovl_aio_rw_complete;
405		refcount_set(&aio_req->ref, 2);
406		ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter);
407		ovl_aio_put(aio_req);
408		if (ret != -EIOCBQUEUED)
409			ovl_aio_cleanup_handler(aio_req);
410	}
411out:
412	revert_creds(old_cred);
413out_fdput:
414	fdput(real);
415
416out_unlock:
417	inode_unlock(inode);
418
419	return ret;
420}
421
422/*
423 * Calling iter_file_splice_write() directly from overlay's f_op may deadlock
424 * due to lock order inversion between pipe->mutex in iter_file_splice_write()
425 * and file_start_write(real.file) in ovl_write_iter().
426 *
427 * So do everything ovl_write_iter() does and call iter_file_splice_write() on
428 * the real file.
429 */
430static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
431				loff_t *ppos, size_t len, unsigned int flags)
432{
433	struct fd real;
434	const struct cred *old_cred;
435	struct inode *inode = file_inode(out);
436	struct inode *realinode = ovl_inode_real(inode);
437	ssize_t ret;
438
439	inode_lock(inode);
440	/* Update mode */
441	ovl_copyattr(realinode, inode);
442	ret = file_remove_privs(out);
443	if (ret)
444		goto out_unlock;
445
446	ret = ovl_real_fdget(out, &real);
447	if (ret)
448		goto out_unlock;
449
450	old_cred = ovl_override_creds(inode->i_sb);
451	file_start_write(real.file);
452
453	ret = iter_file_splice_write(pipe, real.file, ppos, len, flags);
454
455	file_end_write(real.file);
456	/* Update size */
457	ovl_copyattr(realinode, inode);
458	revert_creds(old_cred);
459	fdput(real);
460
461out_unlock:
462	inode_unlock(inode);
463
464	return ret;
465}
466
467static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
468{
469	struct fd real;
470	const struct cred *old_cred;
471	int ret;
472
473	ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb));
474	if (ret <= 0)
475		return ret;
476
477	ret = ovl_real_fdget_meta(file, &real, !datasync);
478	if (ret)
479		return ret;
480
481	/* Don't sync lower file for fear of receiving EROFS error */
482	if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) {
483		old_cred = ovl_override_creds(file_inode(file)->i_sb);
484		ret = vfs_fsync_range(real.file, start, end, datasync);
485		revert_creds(old_cred);
486	}
487
488	fdput(real);
489
490	return ret;
491}
492
493static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
494{
495	struct file *realfile = file->private_data;
496	const struct cred *old_cred;
497	int ret;
498
499	if (!realfile->f_op->mmap)
500		return -ENODEV;
501
502	if (WARN_ON(file != vma->vm_file))
503		return -EIO;
504
505	vma->vm_file = get_file(realfile);
506
507	old_cred = ovl_override_creds(file_inode(file)->i_sb);
508	ret = call_mmap(vma->vm_file, vma);
509	revert_creds(old_cred);
510
511	if (ret) {
512		/* Drop reference count from new vm_file value */
513		fput(realfile);
514	} else {
515		/* Drop reference count from previous vm_file value */
516		fput(file);
517	}
518
519	ovl_file_accessed(file);
520
521	return ret;
522}
523
524static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
525{
526	struct inode *inode = file_inode(file);
527	struct fd real;
528	const struct cred *old_cred;
529	int ret;
530
531	inode_lock(inode);
532	/* Update mode */
533	ovl_copyattr(ovl_inode_real(inode), inode);
534	ret = file_remove_privs(file);
535	if (ret)
536		goto out_unlock;
537
538	ret = ovl_real_fdget(file, &real);
539	if (ret)
540		goto out_unlock;
541
542	old_cred = ovl_override_creds(file_inode(file)->i_sb);
543	ret = vfs_fallocate(real.file, mode, offset, len);
544	revert_creds(old_cred);
545
546	/* Update size */
547	ovl_copyattr(ovl_inode_real(inode), inode);
548
549	fdput(real);
550
551out_unlock:
552	inode_unlock(inode);
553
554	return ret;
555}
556
557static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
558{
559	struct fd real;
560	const struct cred *old_cred;
561	int ret;
562
563	ret = ovl_real_fdget(file, &real);
564	if (ret)
565		return ret;
566
567	old_cred = ovl_override_creds(file_inode(file)->i_sb);
568	ret = vfs_fadvise(real.file, offset, len, advice);
569	revert_creds(old_cred);
570
571	fdput(real);
572
573	return ret;
574}
575
576static long ovl_real_ioctl(struct file *file, unsigned int cmd,
577			   unsigned long arg)
578{
579	struct fd real;
580	long ret;
581
582	ret = ovl_real_fdget(file, &real);
583	if (ret)
584		return ret;
585
586	ret = security_file_ioctl(real.file, cmd, arg);
587	if (!ret) {
588		/*
589		 * Don't override creds, since we currently can't safely check
590		 * permissions before doing so.
591		 */
592		ret = vfs_ioctl(real.file, cmd, arg);
593	}
594
595	fdput(real);
596
597	return ret;
598}
599
600static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
601				unsigned long arg)
602{
603	long ret;
604	struct inode *inode = file_inode(file);
605
606	if (!inode_owner_or_capable(inode))
607		return -EACCES;
608
609	ret = mnt_want_write_file(file);
610	if (ret)
611		return ret;
612
613	inode_lock(inode);
614
615	/*
616	 * Prevent copy up if immutable and has no CAP_LINUX_IMMUTABLE
617	 * capability.
618	 */
619	ret = -EPERM;
620	if (!ovl_has_upperdata(inode) && IS_IMMUTABLE(inode) &&
621	    !capable(CAP_LINUX_IMMUTABLE))
622		goto unlock;
623
624	ret = ovl_maybe_copy_up(file_dentry(file), O_WRONLY);
625	if (ret)
626		goto unlock;
627
628	ret = ovl_real_ioctl(file, cmd, arg);
629
630	ovl_copyflags(ovl_inode_real(inode), inode);
631unlock:
632	inode_unlock(inode);
633
634	mnt_drop_write_file(file);
635
636	return ret;
637
638}
639
640long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
641{
642	long ret;
643
644	switch (cmd) {
645	case FS_IOC_GETFLAGS:
646	case FS_IOC_FSGETXATTR:
647		ret = ovl_real_ioctl(file, cmd, arg);
648		break;
649
650	case FS_IOC_FSSETXATTR:
651	case FS_IOC_SETFLAGS:
652		ret = ovl_ioctl_set_flags(file, cmd, arg);
653		break;
654
655	default:
656		ret = -ENOTTY;
657	}
658
659	return ret;
660}
661
662#ifdef CONFIG_COMPAT
663long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
664{
665	switch (cmd) {
666	case FS_IOC32_GETFLAGS:
667		cmd = FS_IOC_GETFLAGS;
668		break;
669
670	case FS_IOC32_SETFLAGS:
671		cmd = FS_IOC_SETFLAGS;
672		break;
673
674	default:
675		return -ENOIOCTLCMD;
676	}
677
678	return ovl_ioctl(file, cmd, arg);
679}
680#endif
681
682enum ovl_copyop {
683	OVL_COPY,
684	OVL_CLONE,
685	OVL_DEDUPE,
686};
687
688static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
689			    struct file *file_out, loff_t pos_out,
690			    loff_t len, unsigned int flags, enum ovl_copyop op)
691{
692	struct inode *inode_out = file_inode(file_out);
693	struct fd real_in, real_out;
694	const struct cred *old_cred;
695	loff_t ret;
696
697	inode_lock(inode_out);
698	if (op != OVL_DEDUPE) {
699		/* Update mode */
700		ovl_copyattr(ovl_inode_real(inode_out), inode_out);
701		ret = file_remove_privs(file_out);
702		if (ret)
703			goto out_unlock;
704	}
705
706	ret = ovl_real_fdget(file_out, &real_out);
707	if (ret)
708		goto out_unlock;
709
710	ret = ovl_real_fdget(file_in, &real_in);
711	if (ret) {
712		fdput(real_out);
713		goto out_unlock;
714	}
715
716	old_cred = ovl_override_creds(file_inode(file_out)->i_sb);
717	switch (op) {
718	case OVL_COPY:
719		ret = vfs_copy_file_range(real_in.file, pos_in,
720					  real_out.file, pos_out, len, flags);
721		break;
722
723	case OVL_CLONE:
724		ret = vfs_clone_file_range(real_in.file, pos_in,
725					   real_out.file, pos_out, len, flags);
726		break;
727
728	case OVL_DEDUPE:
729		ret = vfs_dedupe_file_range_one(real_in.file, pos_in,
730						real_out.file, pos_out, len,
731						flags);
732		break;
733	}
734	revert_creds(old_cred);
735
736	/* Update size */
737	ovl_copyattr(ovl_inode_real(inode_out), inode_out);
738
739	fdput(real_in);
740	fdput(real_out);
741
742out_unlock:
743	inode_unlock(inode_out);
744
745	return ret;
746}
747
748static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,
749				   struct file *file_out, loff_t pos_out,
750				   size_t len, unsigned int flags)
751{
752	return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags,
753			    OVL_COPY);
754}
755
756static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in,
757				   struct file *file_out, loff_t pos_out,
758				   loff_t len, unsigned int remap_flags)
759{
760	enum ovl_copyop op;
761
762	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
763		return -EINVAL;
764
765	if (remap_flags & REMAP_FILE_DEDUP)
766		op = OVL_DEDUPE;
767	else
768		op = OVL_CLONE;
769
770	/*
771	 * Don't copy up because of a dedupe request, this wouldn't make sense
772	 * most of the time (data would be duplicated instead of deduplicated).
773	 */
774	if (op == OVL_DEDUPE &&
775	    (!ovl_inode_upper(file_inode(file_in)) ||
776	     !ovl_inode_upper(file_inode(file_out))))
777		return -EPERM;
778
779	return ovl_copyfile(file_in, pos_in, file_out, pos_out, len,
780			    remap_flags, op);
781}
782
783const struct file_operations ovl_file_operations = {
784	.open		= ovl_open,
785	.release	= ovl_release,
786	.llseek		= ovl_llseek,
787	.read_iter	= ovl_read_iter,
788	.write_iter	= ovl_write_iter,
789	.fsync		= ovl_fsync,
790	.mmap		= ovl_mmap,
791	.fallocate	= ovl_fallocate,
792	.fadvise	= ovl_fadvise,
793	.unlocked_ioctl	= ovl_ioctl,
794#ifdef CONFIG_COMPAT
795	.compat_ioctl	= ovl_compat_ioctl,
796#endif
797	.splice_read    = generic_file_splice_read,
798	.splice_write   = ovl_splice_write,
799
800	.copy_file_range	= ovl_copy_file_range,
801	.remap_file_range	= ovl_remap_file_range,
802};
803
804int __init ovl_aio_request_cache_init(void)
805{
806	ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req",
807						   sizeof(struct ovl_aio_req),
808						   0, SLAB_HWCACHE_ALIGN, NULL);
809	if (!ovl_aio_request_cachep)
810		return -ENOMEM;
811
812	return 0;
813}
814
815void ovl_aio_request_cache_destroy(void)
816{
817	kmem_cache_destroy(ovl_aio_request_cachep);
818}
819