xref: /openbmc/linux/drivers/block/loop.c (revision 1b1dcc1b57a49136f118a0f16367256ff9994a69)
1 /*
2  *  linux/drivers/block/loop.c
3  *
4  *  Written by Theodore Ts'o, 3/29/93
5  *
6  * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
7  * permitted under the GNU General Public License.
8  *
9  * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993
10  * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996
11  *
12  * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994
13  * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996
14  *
15  * Fixed do_loop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997
16  *
17  * Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998
18  *
19  * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998
20  *
21  * Loadable modules and other fixes by AK, 1998
22  *
23  * Make real block number available to downstream transfer functions, enables
24  * CBC (and relatives) mode encryption requiring unique IVs per data block.
25  * Reed H. Petty, rhp@draper.net
26  *
27  * Maximum number of loop devices now dynamic via max_loop module parameter.
28  * Russell Kroll <rkroll@exploits.org> 19990701
29  *
30  * Maximum number of loop devices when compiled-in now selectable by passing
31  * max_loop=<1-255> to the kernel on boot.
32  * Erik I. Bols�, <eriki@himolde.no>, Oct 31, 1999
33  *
34  * Completely rewrite request handling to be make_request_fn style and
35  * non blocking, pushing work to a helper thread. Lots of fixes from
36  * Al Viro too.
37  * Jens Axboe <axboe@suse.de>, Nov 2000
38  *
39  * Support up to 256 loop devices
40  * Heinz Mauelshagen <mge@sistina.com>, Feb 2002
41  *
42  * Support for falling back on the write file operation when the address space
43  * operations prepare_write and/or commit_write are not available on the
44  * backing filesystem.
45  * Anton Altaparmakov, 16 Feb 2005
46  *
47  * Still To Fix:
48  * - Advisory locking is ignored here.
49  * - Should use an own CAP_* category instead of CAP_SYS_ADMIN
50  *
51  */
52 
53 #include <linux/config.h>
54 #include <linux/module.h>
55 #include <linux/moduleparam.h>
56 #include <linux/sched.h>
57 #include <linux/fs.h>
58 #include <linux/file.h>
59 #include <linux/stat.h>
60 #include <linux/errno.h>
61 #include <linux/major.h>
62 #include <linux/wait.h>
63 #include <linux/blkdev.h>
64 #include <linux/blkpg.h>
65 #include <linux/init.h>
66 #include <linux/devfs_fs_kernel.h>
67 #include <linux/smp_lock.h>
68 #include <linux/swap.h>
69 #include <linux/slab.h>
70 #include <linux/loop.h>
71 #include <linux/suspend.h>
72 #include <linux/writeback.h>
73 #include <linux/buffer_head.h>		/* for invalidate_bdev() */
74 #include <linux/completion.h>
75 #include <linux/highmem.h>
76 #include <linux/gfp.h>
77 
78 #include <asm/uaccess.h>
79 
80 static int max_loop = 8;
81 static struct loop_device *loop_dev;
82 static struct gendisk **disks;
83 
84 /*
85  * Transfer functions
86  */
87 static int transfer_none(struct loop_device *lo, int cmd,
88 			 struct page *raw_page, unsigned raw_off,
89 			 struct page *loop_page, unsigned loop_off,
90 			 int size, sector_t real_block)
91 {
92 	char *raw_buf = kmap_atomic(raw_page, KM_USER0) + raw_off;
93 	char *loop_buf = kmap_atomic(loop_page, KM_USER1) + loop_off;
94 
95 	if (cmd == READ)
96 		memcpy(loop_buf, raw_buf, size);
97 	else
98 		memcpy(raw_buf, loop_buf, size);
99 
100 	kunmap_atomic(raw_buf, KM_USER0);
101 	kunmap_atomic(loop_buf, KM_USER1);
102 	cond_resched();
103 	return 0;
104 }
105 
106 static int transfer_xor(struct loop_device *lo, int cmd,
107 			struct page *raw_page, unsigned raw_off,
108 			struct page *loop_page, unsigned loop_off,
109 			int size, sector_t real_block)
110 {
111 	char *raw_buf = kmap_atomic(raw_page, KM_USER0) + raw_off;
112 	char *loop_buf = kmap_atomic(loop_page, KM_USER1) + loop_off;
113 	char *in, *out, *key;
114 	int i, keysize;
115 
116 	if (cmd == READ) {
117 		in = raw_buf;
118 		out = loop_buf;
119 	} else {
120 		in = loop_buf;
121 		out = raw_buf;
122 	}
123 
124 	key = lo->lo_encrypt_key;
125 	keysize = lo->lo_encrypt_key_size;
126 	for (i = 0; i < size; i++)
127 		*out++ = *in++ ^ key[(i & 511) % keysize];
128 
129 	kunmap_atomic(raw_buf, KM_USER0);
130 	kunmap_atomic(loop_buf, KM_USER1);
131 	cond_resched();
132 	return 0;
133 }
134 
135 static int xor_init(struct loop_device *lo, const struct loop_info64 *info)
136 {
137 	if (unlikely(info->lo_encrypt_key_size <= 0))
138 		return -EINVAL;
139 	return 0;
140 }
141 
142 static struct loop_func_table none_funcs = {
143 	.number = LO_CRYPT_NONE,
144 	.transfer = transfer_none,
145 };
146 
147 static struct loop_func_table xor_funcs = {
148 	.number = LO_CRYPT_XOR,
149 	.transfer = transfer_xor,
150 	.init = xor_init
151 };
152 
153 /* xfer_funcs[0] is special - its release function is never called */
154 static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = {
155 	&none_funcs,
156 	&xor_funcs
157 };
158 
159 static loff_t get_loop_size(struct loop_device *lo, struct file *file)
160 {
161 	loff_t size, offset, loopsize;
162 
163 	/* Compute loopsize in bytes */
164 	size = i_size_read(file->f_mapping->host);
165 	offset = lo->lo_offset;
166 	loopsize = size - offset;
167 	if (lo->lo_sizelimit > 0 && lo->lo_sizelimit < loopsize)
168 		loopsize = lo->lo_sizelimit;
169 
170 	/*
171 	 * Unfortunately, if we want to do I/O on the device,
172 	 * the number of 512-byte sectors has to fit into a sector_t.
173 	 */
174 	return loopsize >> 9;
175 }
176 
177 static int
178 figure_loop_size(struct loop_device *lo)
179 {
180 	loff_t size = get_loop_size(lo, lo->lo_backing_file);
181 	sector_t x = (sector_t)size;
182 
183 	if (unlikely((loff_t)x != size))
184 		return -EFBIG;
185 
186 	set_capacity(disks[lo->lo_number], x);
187 	return 0;
188 }
189 
190 static inline int
191 lo_do_transfer(struct loop_device *lo, int cmd,
192 	       struct page *rpage, unsigned roffs,
193 	       struct page *lpage, unsigned loffs,
194 	       int size, sector_t rblock)
195 {
196 	if (unlikely(!lo->transfer))
197 		return 0;
198 
199 	return lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock);
200 }
201 
202 /**
203  * do_lo_send_aops - helper for writing data to a loop device
204  *
205  * This is the fast version for backing filesystems which implement the address
206  * space operations prepare_write and commit_write.
207  */
208 static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec,
209 		int bsize, loff_t pos, struct page *page)
210 {
211 	struct file *file = lo->lo_backing_file; /* kudos to NFsckingS */
212 	struct address_space *mapping = file->f_mapping;
213 	struct address_space_operations *aops = mapping->a_ops;
214 	pgoff_t index;
215 	unsigned offset, bv_offs;
216 	int len, ret;
217 
218 	mutex_lock(&mapping->host->i_mutex);
219 	index = pos >> PAGE_CACHE_SHIFT;
220 	offset = pos & ((pgoff_t)PAGE_CACHE_SIZE - 1);
221 	bv_offs = bvec->bv_offset;
222 	len = bvec->bv_len;
223 	while (len > 0) {
224 		sector_t IV;
225 		unsigned size;
226 		int transfer_result;
227 
228 		IV = ((sector_t)index << (PAGE_CACHE_SHIFT - 9))+(offset >> 9);
229 		size = PAGE_CACHE_SIZE - offset;
230 		if (size > len)
231 			size = len;
232 		page = grab_cache_page(mapping, index);
233 		if (unlikely(!page))
234 			goto fail;
235 		ret = aops->prepare_write(file, page, offset,
236 					  offset + size);
237 		if (unlikely(ret)) {
238 			if (ret == AOP_TRUNCATED_PAGE) {
239 				page_cache_release(page);
240 				continue;
241 			}
242 			goto unlock;
243 		}
244 		transfer_result = lo_do_transfer(lo, WRITE, page, offset,
245 				bvec->bv_page, bv_offs, size, IV);
246 		if (unlikely(transfer_result)) {
247 			char *kaddr;
248 
249 			/*
250 			 * The transfer failed, but we still write the data to
251 			 * keep prepare/commit calls balanced.
252 			 */
253 			printk(KERN_ERR "loop: transfer error block %llu\n",
254 			       (unsigned long long)index);
255 			kaddr = kmap_atomic(page, KM_USER0);
256 			memset(kaddr + offset, 0, size);
257 			kunmap_atomic(kaddr, KM_USER0);
258 		}
259 		flush_dcache_page(page);
260 		ret = aops->commit_write(file, page, offset,
261 					 offset + size);
262 		if (unlikely(ret)) {
263 			if (ret == AOP_TRUNCATED_PAGE) {
264 				page_cache_release(page);
265 				continue;
266 			}
267 			goto unlock;
268 		}
269 		if (unlikely(transfer_result))
270 			goto unlock;
271 		bv_offs += size;
272 		len -= size;
273 		offset = 0;
274 		index++;
275 		pos += size;
276 		unlock_page(page);
277 		page_cache_release(page);
278 	}
279 	ret = 0;
280 out:
281 	mutex_unlock(&mapping->host->i_mutex);
282 	return ret;
283 unlock:
284 	unlock_page(page);
285 	page_cache_release(page);
286 fail:
287 	ret = -1;
288 	goto out;
289 }
290 
291 /**
292  * __do_lo_send_write - helper for writing data to a loop device
293  *
294  * This helper just factors out common code between do_lo_send_direct_write()
295  * and do_lo_send_write().
296  */
297 static inline int __do_lo_send_write(struct file *file,
298 		u8 __user *buf, const int len, loff_t pos)
299 {
300 	ssize_t bw;
301 	mm_segment_t old_fs = get_fs();
302 
303 	set_fs(get_ds());
304 	bw = file->f_op->write(file, buf, len, &pos);
305 	set_fs(old_fs);
306 	if (likely(bw == len))
307 		return 0;
308 	printk(KERN_ERR "loop: Write error at byte offset %llu, length %i.\n",
309 			(unsigned long long)pos, len);
310 	if (bw >= 0)
311 		bw = -EIO;
312 	return bw;
313 }
314 
315 /**
316  * do_lo_send_direct_write - helper for writing data to a loop device
317  *
318  * This is the fast, non-transforming version for backing filesystems which do
319  * not implement the address space operations prepare_write and commit_write.
320  * It uses the write file operation which should be present on all writeable
321  * filesystems.
322  */
323 static int do_lo_send_direct_write(struct loop_device *lo,
324 		struct bio_vec *bvec, int bsize, loff_t pos, struct page *page)
325 {
326 	ssize_t bw = __do_lo_send_write(lo->lo_backing_file,
327 			(u8 __user *)kmap(bvec->bv_page) + bvec->bv_offset,
328 			bvec->bv_len, pos);
329 	kunmap(bvec->bv_page);
330 	cond_resched();
331 	return bw;
332 }
333 
334 /**
335  * do_lo_send_write - helper for writing data to a loop device
336  *
337  * This is the slow, transforming version for filesystems which do not
338  * implement the address space operations prepare_write and commit_write.  It
339  * uses the write file operation which should be present on all writeable
340  * filesystems.
341  *
342  * Using fops->write is slower than using aops->{prepare,commit}_write in the
343  * transforming case because we need to double buffer the data as we cannot do
344  * the transformations in place as we do not have direct access to the
345  * destination pages of the backing file.
346  */
347 static int do_lo_send_write(struct loop_device *lo, struct bio_vec *bvec,
348 		int bsize, loff_t pos, struct page *page)
349 {
350 	int ret = lo_do_transfer(lo, WRITE, page, 0, bvec->bv_page,
351 			bvec->bv_offset, bvec->bv_len, pos >> 9);
352 	if (likely(!ret))
353 		return __do_lo_send_write(lo->lo_backing_file,
354 				(u8 __user *)page_address(page), bvec->bv_len,
355 				pos);
356 	printk(KERN_ERR "loop: Transfer error at byte offset %llu, "
357 			"length %i.\n", (unsigned long long)pos, bvec->bv_len);
358 	if (ret > 0)
359 		ret = -EIO;
360 	return ret;
361 }
362 
363 static int lo_send(struct loop_device *lo, struct bio *bio, int bsize,
364 		loff_t pos)
365 {
366 	int (*do_lo_send)(struct loop_device *, struct bio_vec *, int, loff_t,
367 			struct page *page);
368 	struct bio_vec *bvec;
369 	struct page *page = NULL;
370 	int i, ret = 0;
371 
372 	do_lo_send = do_lo_send_aops;
373 	if (!(lo->lo_flags & LO_FLAGS_USE_AOPS)) {
374 		do_lo_send = do_lo_send_direct_write;
375 		if (lo->transfer != transfer_none) {
376 			page = alloc_page(GFP_NOIO | __GFP_HIGHMEM);
377 			if (unlikely(!page))
378 				goto fail;
379 			kmap(page);
380 			do_lo_send = do_lo_send_write;
381 		}
382 	}
383 	bio_for_each_segment(bvec, bio, i) {
384 		ret = do_lo_send(lo, bvec, bsize, pos, page);
385 		if (ret < 0)
386 			break;
387 		pos += bvec->bv_len;
388 	}
389 	if (page) {
390 		kunmap(page);
391 		__free_page(page);
392 	}
393 out:
394 	return ret;
395 fail:
396 	printk(KERN_ERR "loop: Failed to allocate temporary page for write.\n");
397 	ret = -ENOMEM;
398 	goto out;
399 }
400 
401 struct lo_read_data {
402 	struct loop_device *lo;
403 	struct page *page;
404 	unsigned offset;
405 	int bsize;
406 };
407 
408 static int
409 lo_read_actor(read_descriptor_t *desc, struct page *page,
410 	      unsigned long offset, unsigned long size)
411 {
412 	unsigned long count = desc->count;
413 	struct lo_read_data *p = desc->arg.data;
414 	struct loop_device *lo = p->lo;
415 	sector_t IV;
416 
417 	IV = ((sector_t) page->index << (PAGE_CACHE_SHIFT - 9))+(offset >> 9);
418 
419 	if (size > count)
420 		size = count;
421 
422 	if (lo_do_transfer(lo, READ, page, offset, p->page, p->offset, size, IV)) {
423 		size = 0;
424 		printk(KERN_ERR "loop: transfer error block %ld\n",
425 		       page->index);
426 		desc->error = -EINVAL;
427 	}
428 
429 	flush_dcache_page(p->page);
430 
431 	desc->count = count - size;
432 	desc->written += size;
433 	p->offset += size;
434 	return size;
435 }
436 
437 static int
438 do_lo_receive(struct loop_device *lo,
439 	      struct bio_vec *bvec, int bsize, loff_t pos)
440 {
441 	struct lo_read_data cookie;
442 	struct file *file;
443 	int retval;
444 
445 	cookie.lo = lo;
446 	cookie.page = bvec->bv_page;
447 	cookie.offset = bvec->bv_offset;
448 	cookie.bsize = bsize;
449 	file = lo->lo_backing_file;
450 	retval = file->f_op->sendfile(file, &pos, bvec->bv_len,
451 			lo_read_actor, &cookie);
452 	return (retval < 0)? retval: 0;
453 }
454 
455 static int
456 lo_receive(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos)
457 {
458 	struct bio_vec *bvec;
459 	int i, ret = 0;
460 
461 	bio_for_each_segment(bvec, bio, i) {
462 		ret = do_lo_receive(lo, bvec, bsize, pos);
463 		if (ret < 0)
464 			break;
465 		pos += bvec->bv_len;
466 	}
467 	return ret;
468 }
469 
470 static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
471 {
472 	loff_t pos;
473 	int ret;
474 
475 	pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
476 	if (bio_rw(bio) == WRITE)
477 		ret = lo_send(lo, bio, lo->lo_blocksize, pos);
478 	else
479 		ret = lo_receive(lo, bio, lo->lo_blocksize, pos);
480 	return ret;
481 }
482 
483 /*
484  * Add bio to back of pending list
485  */
486 static void loop_add_bio(struct loop_device *lo, struct bio *bio)
487 {
488 	if (lo->lo_biotail) {
489 		lo->lo_biotail->bi_next = bio;
490 		lo->lo_biotail = bio;
491 	} else
492 		lo->lo_bio = lo->lo_biotail = bio;
493 }
494 
495 /*
496  * Grab first pending buffer
497  */
498 static struct bio *loop_get_bio(struct loop_device *lo)
499 {
500 	struct bio *bio;
501 
502 	if ((bio = lo->lo_bio)) {
503 		if (bio == lo->lo_biotail)
504 			lo->lo_biotail = NULL;
505 		lo->lo_bio = bio->bi_next;
506 		bio->bi_next = NULL;
507 	}
508 
509 	return bio;
510 }
511 
512 static int loop_make_request(request_queue_t *q, struct bio *old_bio)
513 {
514 	struct loop_device *lo = q->queuedata;
515 	int rw = bio_rw(old_bio);
516 
517 	if (rw == READA)
518 		rw = READ;
519 
520 	BUG_ON(!lo || (rw != READ && rw != WRITE));
521 
522 	spin_lock_irq(&lo->lo_lock);
523 	if (lo->lo_state != Lo_bound)
524 		goto out;
525 	if (unlikely(rw == WRITE && (lo->lo_flags & LO_FLAGS_READ_ONLY)))
526 		goto out;
527 	lo->lo_pending++;
528 	loop_add_bio(lo, old_bio);
529 	spin_unlock_irq(&lo->lo_lock);
530 	up(&lo->lo_bh_mutex);
531 	return 0;
532 
533 out:
534 	if (lo->lo_pending == 0)
535 		up(&lo->lo_bh_mutex);
536 	spin_unlock_irq(&lo->lo_lock);
537 	bio_io_error(old_bio, old_bio->bi_size);
538 	return 0;
539 }
540 
541 /*
542  * kick off io on the underlying address space
543  */
544 static void loop_unplug(request_queue_t *q)
545 {
546 	struct loop_device *lo = q->queuedata;
547 
548 	clear_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags);
549 	blk_run_address_space(lo->lo_backing_file->f_mapping);
550 }
551 
552 struct switch_request {
553 	struct file *file;
554 	struct completion wait;
555 };
556 
557 static void do_loop_switch(struct loop_device *, struct switch_request *);
558 
559 static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio)
560 {
561 	if (unlikely(!bio->bi_bdev)) {
562 		do_loop_switch(lo, bio->bi_private);
563 		bio_put(bio);
564 	} else {
565 		int ret = do_bio_filebacked(lo, bio);
566 		bio_endio(bio, bio->bi_size, ret);
567 	}
568 }
569 
570 /*
571  * worker thread that handles reads/writes to file backed loop devices,
572  * to avoid blocking in our make_request_fn. it also does loop decrypting
573  * on reads for block backed loop, as that is too heavy to do from
574  * b_end_io context where irqs may be disabled.
575  */
576 static int loop_thread(void *data)
577 {
578 	struct loop_device *lo = data;
579 	struct bio *bio;
580 
581 	daemonize("loop%d", lo->lo_number);
582 
583 	/*
584 	 * loop can be used in an encrypted device,
585 	 * hence, it mustn't be stopped at all
586 	 * because it could be indirectly used during suspension
587 	 */
588 	current->flags |= PF_NOFREEZE;
589 
590 	set_user_nice(current, -20);
591 
592 	lo->lo_state = Lo_bound;
593 	lo->lo_pending = 1;
594 
595 	/*
596 	 * up sem, we are running
597 	 */
598 	up(&lo->lo_sem);
599 
600 	for (;;) {
601 		int pending;
602 
603 		/*
604 		 * interruptible just to not contribute to load avg
605 		 */
606 		if (down_interruptible(&lo->lo_bh_mutex))
607 			continue;
608 
609 		spin_lock_irq(&lo->lo_lock);
610 
611 		/*
612 		 * could be upped because of tear-down, not pending work
613 		 */
614 		if (unlikely(!lo->lo_pending)) {
615 			spin_unlock_irq(&lo->lo_lock);
616 			break;
617 		}
618 
619 		bio = loop_get_bio(lo);
620 		lo->lo_pending--;
621 		pending = lo->lo_pending;
622 		spin_unlock_irq(&lo->lo_lock);
623 
624 		BUG_ON(!bio);
625 		loop_handle_bio(lo, bio);
626 
627 		/*
628 		 * upped both for pending work and tear-down, lo_pending
629 		 * will hit zero then
630 		 */
631 		if (unlikely(!pending))
632 			break;
633 	}
634 
635 	up(&lo->lo_sem);
636 	return 0;
637 }
638 
639 /*
640  * loop_switch performs the hard work of switching a backing store.
641  * First it needs to flush existing IO, it does this by sending a magic
642  * BIO down the pipe. The completion of this BIO does the actual switch.
643  */
644 static int loop_switch(struct loop_device *lo, struct file *file)
645 {
646 	struct switch_request w;
647 	struct bio *bio = bio_alloc(GFP_KERNEL, 1);
648 	if (!bio)
649 		return -ENOMEM;
650 	init_completion(&w.wait);
651 	w.file = file;
652 	bio->bi_private = &w;
653 	bio->bi_bdev = NULL;
654 	loop_make_request(lo->lo_queue, bio);
655 	wait_for_completion(&w.wait);
656 	return 0;
657 }
658 
659 /*
660  * Do the actual switch; called from the BIO completion routine
661  */
662 static void do_loop_switch(struct loop_device *lo, struct switch_request *p)
663 {
664 	struct file *file = p->file;
665 	struct file *old_file = lo->lo_backing_file;
666 	struct address_space *mapping = file->f_mapping;
667 
668 	mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask);
669 	lo->lo_backing_file = file;
670 	lo->lo_blocksize = mapping->host->i_blksize;
671 	lo->old_gfp_mask = mapping_gfp_mask(mapping);
672 	mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
673 	complete(&p->wait);
674 }
675 
676 
677 /*
678  * loop_change_fd switched the backing store of a loopback device to
679  * a new file. This is useful for operating system installers to free up
680  * the original file and in High Availability environments to switch to
681  * an alternative location for the content in case of server meltdown.
682  * This can only work if the loop device is used read-only, and if the
683  * new backing store is the same size and type as the old backing store.
684  */
685 static int loop_change_fd(struct loop_device *lo, struct file *lo_file,
686 		       struct block_device *bdev, unsigned int arg)
687 {
688 	struct file	*file, *old_file;
689 	struct inode	*inode;
690 	int		error;
691 
692 	error = -ENXIO;
693 	if (lo->lo_state != Lo_bound)
694 		goto out;
695 
696 	/* the loop device has to be read-only */
697 	error = -EINVAL;
698 	if (!(lo->lo_flags & LO_FLAGS_READ_ONLY))
699 		goto out;
700 
701 	error = -EBADF;
702 	file = fget(arg);
703 	if (!file)
704 		goto out;
705 
706 	inode = file->f_mapping->host;
707 	old_file = lo->lo_backing_file;
708 
709 	error = -EINVAL;
710 
711 	if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
712 		goto out_putf;
713 
714 	/* new backing store needs to support loop (eg sendfile) */
715 	if (!inode->i_fop->sendfile)
716 		goto out_putf;
717 
718 	/* size of the new backing store needs to be the same */
719 	if (get_loop_size(lo, file) != get_loop_size(lo, old_file))
720 		goto out_putf;
721 
722 	/* and ... switch */
723 	error = loop_switch(lo, file);
724 	if (error)
725 		goto out_putf;
726 
727 	fput(old_file);
728 	return 0;
729 
730  out_putf:
731 	fput(file);
732  out:
733 	return error;
734 }
735 
736 static inline int is_loop_device(struct file *file)
737 {
738 	struct inode *i = file->f_mapping->host;
739 
740 	return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR;
741 }
742 
743 static int loop_set_fd(struct loop_device *lo, struct file *lo_file,
744 		       struct block_device *bdev, unsigned int arg)
745 {
746 	struct file	*file, *f;
747 	struct inode	*inode;
748 	struct address_space *mapping;
749 	unsigned lo_blocksize;
750 	int		lo_flags = 0;
751 	int		error;
752 	loff_t		size;
753 
754 	/* This is safe, since we have a reference from open(). */
755 	__module_get(THIS_MODULE);
756 
757 	error = -EBADF;
758 	file = fget(arg);
759 	if (!file)
760 		goto out;
761 
762 	error = -EBUSY;
763 	if (lo->lo_state != Lo_unbound)
764 		goto out_putf;
765 
766 	/* Avoid recursion */
767 	f = file;
768 	while (is_loop_device(f)) {
769 		struct loop_device *l;
770 
771 		if (f->f_mapping->host->i_rdev == lo_file->f_mapping->host->i_rdev)
772 			goto out_putf;
773 
774 		l = f->f_mapping->host->i_bdev->bd_disk->private_data;
775 		if (l->lo_state == Lo_unbound) {
776 			error = -EINVAL;
777 			goto out_putf;
778 		}
779 		f = l->lo_backing_file;
780 	}
781 
782 	mapping = file->f_mapping;
783 	inode = mapping->host;
784 
785 	if (!(file->f_mode & FMODE_WRITE))
786 		lo_flags |= LO_FLAGS_READ_ONLY;
787 
788 	error = -EINVAL;
789 	if (S_ISREG(inode->i_mode) || S_ISBLK(inode->i_mode)) {
790 		struct address_space_operations *aops = mapping->a_ops;
791 		/*
792 		 * If we can't read - sorry. If we only can't write - well,
793 		 * it's going to be read-only.
794 		 */
795 		if (!file->f_op->sendfile)
796 			goto out_putf;
797 		if (aops->prepare_write && aops->commit_write)
798 			lo_flags |= LO_FLAGS_USE_AOPS;
799 		if (!(lo_flags & LO_FLAGS_USE_AOPS) && !file->f_op->write)
800 			lo_flags |= LO_FLAGS_READ_ONLY;
801 
802 		lo_blocksize = inode->i_blksize;
803 		error = 0;
804 	} else {
805 		goto out_putf;
806 	}
807 
808 	size = get_loop_size(lo, file);
809 
810 	if ((loff_t)(sector_t)size != size) {
811 		error = -EFBIG;
812 		goto out_putf;
813 	}
814 
815 	if (!(lo_file->f_mode & FMODE_WRITE))
816 		lo_flags |= LO_FLAGS_READ_ONLY;
817 
818 	set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0);
819 
820 	lo->lo_blocksize = lo_blocksize;
821 	lo->lo_device = bdev;
822 	lo->lo_flags = lo_flags;
823 	lo->lo_backing_file = file;
824 	lo->transfer = NULL;
825 	lo->ioctl = NULL;
826 	lo->lo_sizelimit = 0;
827 	lo->old_gfp_mask = mapping_gfp_mask(mapping);
828 	mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
829 
830 	lo->lo_bio = lo->lo_biotail = NULL;
831 
832 	/*
833 	 * set queue make_request_fn, and add limits based on lower level
834 	 * device
835 	 */
836 	blk_queue_make_request(lo->lo_queue, loop_make_request);
837 	lo->lo_queue->queuedata = lo;
838 	lo->lo_queue->unplug_fn = loop_unplug;
839 
840 	set_capacity(disks[lo->lo_number], size);
841 	bd_set_size(bdev, size << 9);
842 
843 	set_blocksize(bdev, lo_blocksize);
844 
845 	kernel_thread(loop_thread, lo, CLONE_KERNEL);
846 	down(&lo->lo_sem);
847 	return 0;
848 
849  out_putf:
850 	fput(file);
851  out:
852 	/* This is safe: open() is still holding a reference. */
853 	module_put(THIS_MODULE);
854 	return error;
855 }
856 
857 static int
858 loop_release_xfer(struct loop_device *lo)
859 {
860 	int err = 0;
861 	struct loop_func_table *xfer = lo->lo_encryption;
862 
863 	if (xfer) {
864 		if (xfer->release)
865 			err = xfer->release(lo);
866 		lo->transfer = NULL;
867 		lo->lo_encryption = NULL;
868 		module_put(xfer->owner);
869 	}
870 	return err;
871 }
872 
873 static int
874 loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer,
875 	       const struct loop_info64 *i)
876 {
877 	int err = 0;
878 
879 	if (xfer) {
880 		struct module *owner = xfer->owner;
881 
882 		if (!try_module_get(owner))
883 			return -EINVAL;
884 		if (xfer->init)
885 			err = xfer->init(lo, i);
886 		if (err)
887 			module_put(owner);
888 		else
889 			lo->lo_encryption = xfer;
890 	}
891 	return err;
892 }
893 
894 static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
895 {
896 	struct file *filp = lo->lo_backing_file;
897 	gfp_t gfp = lo->old_gfp_mask;
898 
899 	if (lo->lo_state != Lo_bound)
900 		return -ENXIO;
901 
902 	if (lo->lo_refcnt > 1)	/* we needed one fd for the ioctl */
903 		return -EBUSY;
904 
905 	if (filp == NULL)
906 		return -EINVAL;
907 
908 	spin_lock_irq(&lo->lo_lock);
909 	lo->lo_state = Lo_rundown;
910 	lo->lo_pending--;
911 	if (!lo->lo_pending)
912 		up(&lo->lo_bh_mutex);
913 	spin_unlock_irq(&lo->lo_lock);
914 
915 	down(&lo->lo_sem);
916 
917 	lo->lo_backing_file = NULL;
918 
919 	loop_release_xfer(lo);
920 	lo->transfer = NULL;
921 	lo->ioctl = NULL;
922 	lo->lo_device = NULL;
923 	lo->lo_encryption = NULL;
924 	lo->lo_offset = 0;
925 	lo->lo_sizelimit = 0;
926 	lo->lo_encrypt_key_size = 0;
927 	lo->lo_flags = 0;
928 	memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE);
929 	memset(lo->lo_crypt_name, 0, LO_NAME_SIZE);
930 	memset(lo->lo_file_name, 0, LO_NAME_SIZE);
931 	invalidate_bdev(bdev, 0);
932 	set_capacity(disks[lo->lo_number], 0);
933 	bd_set_size(bdev, 0);
934 	mapping_set_gfp_mask(filp->f_mapping, gfp);
935 	lo->lo_state = Lo_unbound;
936 	fput(filp);
937 	/* This is safe: open() is still holding a reference. */
938 	module_put(THIS_MODULE);
939 	return 0;
940 }
941 
942 static int
943 loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
944 {
945 	int err;
946 	struct loop_func_table *xfer;
947 
948 	if (lo->lo_encrypt_key_size && lo->lo_key_owner != current->uid &&
949 	    !capable(CAP_SYS_ADMIN))
950 		return -EPERM;
951 	if (lo->lo_state != Lo_bound)
952 		return -ENXIO;
953 	if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE)
954 		return -EINVAL;
955 
956 	err = loop_release_xfer(lo);
957 	if (err)
958 		return err;
959 
960 	if (info->lo_encrypt_type) {
961 		unsigned int type = info->lo_encrypt_type;
962 
963 		if (type >= MAX_LO_CRYPT)
964 			return -EINVAL;
965 		xfer = xfer_funcs[type];
966 		if (xfer == NULL)
967 			return -EINVAL;
968 	} else
969 		xfer = NULL;
970 
971 	err = loop_init_xfer(lo, xfer, info);
972 	if (err)
973 		return err;
974 
975 	if (lo->lo_offset != info->lo_offset ||
976 	    lo->lo_sizelimit != info->lo_sizelimit) {
977 		lo->lo_offset = info->lo_offset;
978 		lo->lo_sizelimit = info->lo_sizelimit;
979 		if (figure_loop_size(lo))
980 			return -EFBIG;
981 	}
982 
983 	memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
984 	memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
985 	lo->lo_file_name[LO_NAME_SIZE-1] = 0;
986 	lo->lo_crypt_name[LO_NAME_SIZE-1] = 0;
987 
988 	if (!xfer)
989 		xfer = &none_funcs;
990 	lo->transfer = xfer->transfer;
991 	lo->ioctl = xfer->ioctl;
992 
993 	lo->lo_encrypt_key_size = info->lo_encrypt_key_size;
994 	lo->lo_init[0] = info->lo_init[0];
995 	lo->lo_init[1] = info->lo_init[1];
996 	if (info->lo_encrypt_key_size) {
997 		memcpy(lo->lo_encrypt_key, info->lo_encrypt_key,
998 		       info->lo_encrypt_key_size);
999 		lo->lo_key_owner = current->uid;
1000 	}
1001 
1002 	return 0;
1003 }
1004 
1005 static int
1006 loop_get_status(struct loop_device *lo, struct loop_info64 *info)
1007 {
1008 	struct file *file = lo->lo_backing_file;
1009 	struct kstat stat;
1010 	int error;
1011 
1012 	if (lo->lo_state != Lo_bound)
1013 		return -ENXIO;
1014 	error = vfs_getattr(file->f_vfsmnt, file->f_dentry, &stat);
1015 	if (error)
1016 		return error;
1017 	memset(info, 0, sizeof(*info));
1018 	info->lo_number = lo->lo_number;
1019 	info->lo_device = huge_encode_dev(stat.dev);
1020 	info->lo_inode = stat.ino;
1021 	info->lo_rdevice = huge_encode_dev(lo->lo_device ? stat.rdev : stat.dev);
1022 	info->lo_offset = lo->lo_offset;
1023 	info->lo_sizelimit = lo->lo_sizelimit;
1024 	info->lo_flags = lo->lo_flags;
1025 	memcpy(info->lo_file_name, lo->lo_file_name, LO_NAME_SIZE);
1026 	memcpy(info->lo_crypt_name, lo->lo_crypt_name, LO_NAME_SIZE);
1027 	info->lo_encrypt_type =
1028 		lo->lo_encryption ? lo->lo_encryption->number : 0;
1029 	if (lo->lo_encrypt_key_size && capable(CAP_SYS_ADMIN)) {
1030 		info->lo_encrypt_key_size = lo->lo_encrypt_key_size;
1031 		memcpy(info->lo_encrypt_key, lo->lo_encrypt_key,
1032 		       lo->lo_encrypt_key_size);
1033 	}
1034 	return 0;
1035 }
1036 
1037 static void
1038 loop_info64_from_old(const struct loop_info *info, struct loop_info64 *info64)
1039 {
1040 	memset(info64, 0, sizeof(*info64));
1041 	info64->lo_number = info->lo_number;
1042 	info64->lo_device = info->lo_device;
1043 	info64->lo_inode = info->lo_inode;
1044 	info64->lo_rdevice = info->lo_rdevice;
1045 	info64->lo_offset = info->lo_offset;
1046 	info64->lo_sizelimit = 0;
1047 	info64->lo_encrypt_type = info->lo_encrypt_type;
1048 	info64->lo_encrypt_key_size = info->lo_encrypt_key_size;
1049 	info64->lo_flags = info->lo_flags;
1050 	info64->lo_init[0] = info->lo_init[0];
1051 	info64->lo_init[1] = info->lo_init[1];
1052 	if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI)
1053 		memcpy(info64->lo_crypt_name, info->lo_name, LO_NAME_SIZE);
1054 	else
1055 		memcpy(info64->lo_file_name, info->lo_name, LO_NAME_SIZE);
1056 	memcpy(info64->lo_encrypt_key, info->lo_encrypt_key, LO_KEY_SIZE);
1057 }
1058 
1059 static int
1060 loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info)
1061 {
1062 	memset(info, 0, sizeof(*info));
1063 	info->lo_number = info64->lo_number;
1064 	info->lo_device = info64->lo_device;
1065 	info->lo_inode = info64->lo_inode;
1066 	info->lo_rdevice = info64->lo_rdevice;
1067 	info->lo_offset = info64->lo_offset;
1068 	info->lo_encrypt_type = info64->lo_encrypt_type;
1069 	info->lo_encrypt_key_size = info64->lo_encrypt_key_size;
1070 	info->lo_flags = info64->lo_flags;
1071 	info->lo_init[0] = info64->lo_init[0];
1072 	info->lo_init[1] = info64->lo_init[1];
1073 	if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI)
1074 		memcpy(info->lo_name, info64->lo_crypt_name, LO_NAME_SIZE);
1075 	else
1076 		memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE);
1077 	memcpy(info->lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE);
1078 
1079 	/* error in case values were truncated */
1080 	if (info->lo_device != info64->lo_device ||
1081 	    info->lo_rdevice != info64->lo_rdevice ||
1082 	    info->lo_inode != info64->lo_inode ||
1083 	    info->lo_offset != info64->lo_offset)
1084 		return -EOVERFLOW;
1085 
1086 	return 0;
1087 }
1088 
1089 static int
1090 loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg)
1091 {
1092 	struct loop_info info;
1093 	struct loop_info64 info64;
1094 
1095 	if (copy_from_user(&info, arg, sizeof (struct loop_info)))
1096 		return -EFAULT;
1097 	loop_info64_from_old(&info, &info64);
1098 	return loop_set_status(lo, &info64);
1099 }
1100 
1101 static int
1102 loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg)
1103 {
1104 	struct loop_info64 info64;
1105 
1106 	if (copy_from_user(&info64, arg, sizeof (struct loop_info64)))
1107 		return -EFAULT;
1108 	return loop_set_status(lo, &info64);
1109 }
1110 
1111 static int
1112 loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) {
1113 	struct loop_info info;
1114 	struct loop_info64 info64;
1115 	int err = 0;
1116 
1117 	if (!arg)
1118 		err = -EINVAL;
1119 	if (!err)
1120 		err = loop_get_status(lo, &info64);
1121 	if (!err)
1122 		err = loop_info64_to_old(&info64, &info);
1123 	if (!err && copy_to_user(arg, &info, sizeof(info)))
1124 		err = -EFAULT;
1125 
1126 	return err;
1127 }
1128 
1129 static int
1130 loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) {
1131 	struct loop_info64 info64;
1132 	int err = 0;
1133 
1134 	if (!arg)
1135 		err = -EINVAL;
1136 	if (!err)
1137 		err = loop_get_status(lo, &info64);
1138 	if (!err && copy_to_user(arg, &info64, sizeof(info64)))
1139 		err = -EFAULT;
1140 
1141 	return err;
1142 }
1143 
1144 static int lo_ioctl(struct inode * inode, struct file * file,
1145 	unsigned int cmd, unsigned long arg)
1146 {
1147 	struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
1148 	int err;
1149 
1150 	down(&lo->lo_ctl_mutex);
1151 	switch (cmd) {
1152 	case LOOP_SET_FD:
1153 		err = loop_set_fd(lo, file, inode->i_bdev, arg);
1154 		break;
1155 	case LOOP_CHANGE_FD:
1156 		err = loop_change_fd(lo, file, inode->i_bdev, arg);
1157 		break;
1158 	case LOOP_CLR_FD:
1159 		err = loop_clr_fd(lo, inode->i_bdev);
1160 		break;
1161 	case LOOP_SET_STATUS:
1162 		err = loop_set_status_old(lo, (struct loop_info __user *) arg);
1163 		break;
1164 	case LOOP_GET_STATUS:
1165 		err = loop_get_status_old(lo, (struct loop_info __user *) arg);
1166 		break;
1167 	case LOOP_SET_STATUS64:
1168 		err = loop_set_status64(lo, (struct loop_info64 __user *) arg);
1169 		break;
1170 	case LOOP_GET_STATUS64:
1171 		err = loop_get_status64(lo, (struct loop_info64 __user *) arg);
1172 		break;
1173 	default:
1174 		err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL;
1175 	}
1176 	up(&lo->lo_ctl_mutex);
1177 	return err;
1178 }
1179 
1180 static int lo_open(struct inode *inode, struct file *file)
1181 {
1182 	struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
1183 
1184 	down(&lo->lo_ctl_mutex);
1185 	lo->lo_refcnt++;
1186 	up(&lo->lo_ctl_mutex);
1187 
1188 	return 0;
1189 }
1190 
1191 static int lo_release(struct inode *inode, struct file *file)
1192 {
1193 	struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
1194 
1195 	down(&lo->lo_ctl_mutex);
1196 	--lo->lo_refcnt;
1197 	up(&lo->lo_ctl_mutex);
1198 
1199 	return 0;
1200 }
1201 
1202 static struct block_device_operations lo_fops = {
1203 	.owner =	THIS_MODULE,
1204 	.open =		lo_open,
1205 	.release =	lo_release,
1206 	.ioctl =	lo_ioctl,
1207 };
1208 
1209 /*
1210  * And now the modules code and kernel interface.
1211  */
1212 module_param(max_loop, int, 0);
1213 MODULE_PARM_DESC(max_loop, "Maximum number of loop devices (1-256)");
1214 MODULE_LICENSE("GPL");
1215 MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR);
1216 
1217 int loop_register_transfer(struct loop_func_table *funcs)
1218 {
1219 	unsigned int n = funcs->number;
1220 
1221 	if (n >= MAX_LO_CRYPT || xfer_funcs[n])
1222 		return -EINVAL;
1223 	xfer_funcs[n] = funcs;
1224 	return 0;
1225 }
1226 
1227 int loop_unregister_transfer(int number)
1228 {
1229 	unsigned int n = number;
1230 	struct loop_device *lo;
1231 	struct loop_func_table *xfer;
1232 
1233 	if (n == 0 || n >= MAX_LO_CRYPT || (xfer = xfer_funcs[n]) == NULL)
1234 		return -EINVAL;
1235 
1236 	xfer_funcs[n] = NULL;
1237 
1238 	for (lo = &loop_dev[0]; lo < &loop_dev[max_loop]; lo++) {
1239 		down(&lo->lo_ctl_mutex);
1240 
1241 		if (lo->lo_encryption == xfer)
1242 			loop_release_xfer(lo);
1243 
1244 		up(&lo->lo_ctl_mutex);
1245 	}
1246 
1247 	return 0;
1248 }
1249 
1250 EXPORT_SYMBOL(loop_register_transfer);
1251 EXPORT_SYMBOL(loop_unregister_transfer);
1252 
1253 static int __init loop_init(void)
1254 {
1255 	int	i;
1256 
1257 	if (max_loop < 1 || max_loop > 256) {
1258 		printk(KERN_WARNING "loop: invalid max_loop (must be between"
1259 				    " 1 and 256), using default (8)\n");
1260 		max_loop = 8;
1261 	}
1262 
1263 	if (register_blkdev(LOOP_MAJOR, "loop"))
1264 		return -EIO;
1265 
1266 	loop_dev = kmalloc(max_loop * sizeof(struct loop_device), GFP_KERNEL);
1267 	if (!loop_dev)
1268 		goto out_mem1;
1269 	memset(loop_dev, 0, max_loop * sizeof(struct loop_device));
1270 
1271 	disks = kmalloc(max_loop * sizeof(struct gendisk *), GFP_KERNEL);
1272 	if (!disks)
1273 		goto out_mem2;
1274 
1275 	for (i = 0; i < max_loop; i++) {
1276 		disks[i] = alloc_disk(1);
1277 		if (!disks[i])
1278 			goto out_mem3;
1279 	}
1280 
1281 	devfs_mk_dir("loop");
1282 
1283 	for (i = 0; i < max_loop; i++) {
1284 		struct loop_device *lo = &loop_dev[i];
1285 		struct gendisk *disk = disks[i];
1286 
1287 		memset(lo, 0, sizeof(*lo));
1288 		lo->lo_queue = blk_alloc_queue(GFP_KERNEL);
1289 		if (!lo->lo_queue)
1290 			goto out_mem4;
1291 		init_MUTEX(&lo->lo_ctl_mutex);
1292 		init_MUTEX_LOCKED(&lo->lo_sem);
1293 		init_MUTEX_LOCKED(&lo->lo_bh_mutex);
1294 		lo->lo_number = i;
1295 		spin_lock_init(&lo->lo_lock);
1296 		disk->major = LOOP_MAJOR;
1297 		disk->first_minor = i;
1298 		disk->fops = &lo_fops;
1299 		sprintf(disk->disk_name, "loop%d", i);
1300 		sprintf(disk->devfs_name, "loop/%d", i);
1301 		disk->private_data = lo;
1302 		disk->queue = lo->lo_queue;
1303 	}
1304 
1305 	/* We cannot fail after we call this, so another loop!*/
1306 	for (i = 0; i < max_loop; i++)
1307 		add_disk(disks[i]);
1308 	printk(KERN_INFO "loop: loaded (max %d devices)\n", max_loop);
1309 	return 0;
1310 
1311 out_mem4:
1312 	while (i--)
1313 		blk_put_queue(loop_dev[i].lo_queue);
1314 	devfs_remove("loop");
1315 	i = max_loop;
1316 out_mem3:
1317 	while (i--)
1318 		put_disk(disks[i]);
1319 	kfree(disks);
1320 out_mem2:
1321 	kfree(loop_dev);
1322 out_mem1:
1323 	unregister_blkdev(LOOP_MAJOR, "loop");
1324 	printk(KERN_ERR "loop: ran out of memory\n");
1325 	return -ENOMEM;
1326 }
1327 
1328 static void loop_exit(void)
1329 {
1330 	int i;
1331 
1332 	for (i = 0; i < max_loop; i++) {
1333 		del_gendisk(disks[i]);
1334 		blk_put_queue(loop_dev[i].lo_queue);
1335 		put_disk(disks[i]);
1336 	}
1337 	devfs_remove("loop");
1338 	if (unregister_blkdev(LOOP_MAJOR, "loop"))
1339 		printk(KERN_WARNING "loop: cannot unregister blkdev\n");
1340 
1341 	kfree(disks);
1342 	kfree(loop_dev);
1343 }
1344 
1345 module_init(loop_init);
1346 module_exit(loop_exit);
1347 
1348 #ifndef MODULE
1349 static int __init max_loop_setup(char *str)
1350 {
1351 	max_loop = simple_strtol(str, NULL, 0);
1352 	return 1;
1353 }
1354 
1355 __setup("max_loop=", max_loop_setup);
1356 #endif
1357