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