1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * blockcheck.c
5  *
6  * Checksum and ECC codes for the OCFS2 userspace library.
7  *
8  * Copyright (C) 2006, 2008 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License, version 2, as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/types.h>
22 #include <linux/crc32.h>
23 #include <linux/buffer_head.h>
24 #include <linux/bitops.h>
25 #include <linux/debugfs.h>
26 #include <linux/module.h>
27 #include <linux/fs.h>
28 #include <asm/byteorder.h>
29 
30 #include <cluster/masklog.h>
31 
32 #include "ocfs2.h"
33 
34 #include "blockcheck.h"
35 
36 
37 /*
38  * We use the following conventions:
39  *
40  * d = # data bits
41  * p = # parity bits
42  * c = # total code bits (d + p)
43  */
44 
45 
46 /*
47  * Calculate the bit offset in the hamming code buffer based on the bit's
48  * offset in the data buffer.  Since the hamming code reserves all
49  * power-of-two bits for parity, the data bit number and the code bit
50  * number are offset by all the parity bits beforehand.
51  *
52  * Recall that bit numbers in hamming code are 1-based.  This function
53  * takes the 0-based data bit from the caller.
54  *
55  * An example.  Take bit 1 of the data buffer.  1 is a power of two (2^0),
56  * so it's a parity bit.  2 is a power of two (2^1), so it's a parity bit.
57  * 3 is not a power of two.  So bit 1 of the data buffer ends up as bit 3
58  * in the code buffer.
59  *
60  * The caller can pass in *p if it wants to keep track of the most recent
61  * number of parity bits added.  This allows the function to start the
62  * calculation at the last place.
63  */
calc_code_bit(unsigned int i,unsigned int * p_cache)64 static unsigned int calc_code_bit(unsigned int i, unsigned int *p_cache)
65 {
66 	unsigned int b, p = 0;
67 
68 	/*
69 	 * Data bits are 0-based, but we're talking code bits, which
70 	 * are 1-based.
71 	 */
72 	b = i + 1;
73 
74 	/* Use the cache if it is there */
75 	if (p_cache)
76 		p = *p_cache;
77         b += p;
78 
79 	/*
80 	 * For every power of two below our bit number, bump our bit.
81 	 *
82 	 * We compare with (b + 1) because we have to compare with what b
83 	 * would be _if_ it were bumped up by the parity bit.  Capice?
84 	 *
85 	 * p is set above.
86 	 */
87 	for (; (1 << p) < (b + 1); p++)
88 		b++;
89 
90 	if (p_cache)
91 		*p_cache = p;
92 
93 	return b;
94 }
95 
96 /*
97  * This is the low level encoder function.  It can be called across
98  * multiple hunks just like the crc32 code.  'd' is the number of bits
99  * _in_this_hunk_.  nr is the bit offset of this hunk.  So, if you had
100  * two 512B buffers, you would do it like so:
101  *
102  * parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0);
103  * parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8);
104  *
105  * If you just have one buffer, use ocfs2_hamming_encode_block().
106  */
ocfs2_hamming_encode(u32 parity,void * data,unsigned int d,unsigned int nr)107 u32 ocfs2_hamming_encode(u32 parity, void *data, unsigned int d, unsigned int nr)
108 {
109 	unsigned int i, b, p = 0;
110 
111 	BUG_ON(!d);
112 
113 	/*
114 	 * b is the hamming code bit number.  Hamming code specifies a
115 	 * 1-based array, but C uses 0-based.  So 'i' is for C, and 'b' is
116 	 * for the algorithm.
117 	 *
118 	 * The i++ in the for loop is so that the start offset passed
119 	 * to ocfs2_find_next_bit_set() is one greater than the previously
120 	 * found bit.
121 	 */
122 	for (i = 0; (i = ocfs2_find_next_bit(data, d, i)) < d; i++)
123 	{
124 		/*
125 		 * i is the offset in this hunk, nr + i is the total bit
126 		 * offset.
127 		 */
128 		b = calc_code_bit(nr + i, &p);
129 
130 		/*
131 		 * Data bits in the resultant code are checked by
132 		 * parity bits that are part of the bit number
133 		 * representation.  Huh?
134 		 *
135 		 * <wikipedia href="http://en.wikipedia.org/wiki/Hamming_code">
136 		 * In other words, the parity bit at position 2^k
137 		 * checks bits in positions having bit k set in
138 		 * their binary representation.  Conversely, for
139 		 * instance, bit 13, i.e. 1101(2), is checked by
140 		 * bits 1000(2) = 8, 0100(2)=4 and 0001(2) = 1.
141 		 * </wikipedia>
142 		 *
143 		 * Note that 'k' is the _code_ bit number.  'b' in
144 		 * our loop.
145 		 */
146 		parity ^= b;
147 	}
148 
149 	/* While the data buffer was treated as little endian, the
150 	 * return value is in host endian. */
151 	return parity;
152 }
153 
ocfs2_hamming_encode_block(void * data,unsigned int blocksize)154 u32 ocfs2_hamming_encode_block(void *data, unsigned int blocksize)
155 {
156 	return ocfs2_hamming_encode(0, data, blocksize * 8, 0);
157 }
158 
159 /*
160  * Like ocfs2_hamming_encode(), this can handle hunks.  nr is the bit
161  * offset of the current hunk.  If bit to be fixed is not part of the
162  * current hunk, this does nothing.
163  *
164  * If you only have one hunk, use ocfs2_hamming_fix_block().
165  */
ocfs2_hamming_fix(void * data,unsigned int d,unsigned int nr,unsigned int fix)166 void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr,
167 		       unsigned int fix)
168 {
169 	unsigned int i, b;
170 
171 	BUG_ON(!d);
172 
173 	/*
174 	 * If the bit to fix has an hweight of 1, it's a parity bit.  One
175 	 * busted parity bit is its own error.  Nothing to do here.
176 	 */
177 	if (hweight32(fix) == 1)
178 		return;
179 
180 	/*
181 	 * nr + d is the bit right past the data hunk we're looking at.
182 	 * If fix after that, nothing to do
183 	 */
184 	if (fix >= calc_code_bit(nr + d, NULL))
185 		return;
186 
187 	/*
188 	 * nr is the offset in the data hunk we're starting at.  Let's
189 	 * start b at the offset in the code buffer.  See hamming_encode()
190 	 * for a more detailed description of 'b'.
191 	 */
192 	b = calc_code_bit(nr, NULL);
193 	/* If the fix is before this hunk, nothing to do */
194 	if (fix < b)
195 		return;
196 
197 	for (i = 0; i < d; i++, b++)
198 	{
199 		/* Skip past parity bits */
200 		while (hweight32(b) == 1)
201 			b++;
202 
203 		/*
204 		 * i is the offset in this data hunk.
205 		 * nr + i is the offset in the total data buffer.
206 		 * b is the offset in the total code buffer.
207 		 *
208 		 * Thus, when b == fix, bit i in the current hunk needs
209 		 * fixing.
210 		 */
211 		if (b == fix)
212 		{
213 			if (ocfs2_test_bit(i, data))
214 				ocfs2_clear_bit(i, data);
215 			else
216 				ocfs2_set_bit(i, data);
217 			break;
218 		}
219 	}
220 }
221 
ocfs2_hamming_fix_block(void * data,unsigned int blocksize,unsigned int fix)222 void ocfs2_hamming_fix_block(void *data, unsigned int blocksize,
223 			     unsigned int fix)
224 {
225 	ocfs2_hamming_fix(data, blocksize * 8, 0, fix);
226 }
227 
228 
229 /*
230  * Debugfs handling.
231  */
232 
233 #ifdef CONFIG_DEBUG_FS
234 
blockcheck_u64_get(void * data,u64 * val)235 static int blockcheck_u64_get(void *data, u64 *val)
236 {
237 	*val = *(u64 *)data;
238 	return 0;
239 }
240 DEFINE_SIMPLE_ATTRIBUTE(blockcheck_fops, blockcheck_u64_get, NULL, "%llu\n");
241 
blockcheck_debugfs_create(const char * name,struct dentry * parent,u64 * value)242 static struct dentry *blockcheck_debugfs_create(const char *name,
243 						struct dentry *parent,
244 						u64 *value)
245 {
246 	return debugfs_create_file(name, S_IFREG | S_IRUSR, parent, value,
247 				   &blockcheck_fops);
248 }
249 
ocfs2_blockcheck_debug_remove(struct ocfs2_blockcheck_stats * stats)250 static void ocfs2_blockcheck_debug_remove(struct ocfs2_blockcheck_stats *stats)
251 {
252 	if (stats) {
253 		debugfs_remove(stats->b_debug_check);
254 		stats->b_debug_check = NULL;
255 		debugfs_remove(stats->b_debug_failure);
256 		stats->b_debug_failure = NULL;
257 		debugfs_remove(stats->b_debug_recover);
258 		stats->b_debug_recover = NULL;
259 		debugfs_remove(stats->b_debug_dir);
260 		stats->b_debug_dir = NULL;
261 	}
262 }
263 
ocfs2_blockcheck_debug_install(struct ocfs2_blockcheck_stats * stats,struct dentry * parent)264 static int ocfs2_blockcheck_debug_install(struct ocfs2_blockcheck_stats *stats,
265 					  struct dentry *parent)
266 {
267 	int rc = -EINVAL;
268 
269 	if (!stats)
270 		goto out;
271 
272 	stats->b_debug_dir = debugfs_create_dir("blockcheck", parent);
273 	if (!stats->b_debug_dir)
274 		goto out;
275 
276 	stats->b_debug_check =
277 		blockcheck_debugfs_create("blocks_checked",
278 					  stats->b_debug_dir,
279 					  &stats->b_check_count);
280 
281 	stats->b_debug_failure =
282 		blockcheck_debugfs_create("checksums_failed",
283 					  stats->b_debug_dir,
284 					  &stats->b_failure_count);
285 
286 	stats->b_debug_recover =
287 		blockcheck_debugfs_create("ecc_recoveries",
288 					  stats->b_debug_dir,
289 					  &stats->b_recover_count);
290 	if (stats->b_debug_check && stats->b_debug_failure &&
291 	    stats->b_debug_recover)
292 		rc = 0;
293 
294 out:
295 	if (rc)
296 		ocfs2_blockcheck_debug_remove(stats);
297 	return rc;
298 }
299 #else
ocfs2_blockcheck_debug_install(struct ocfs2_blockcheck_stats * stats,struct dentry * parent)300 static inline int ocfs2_blockcheck_debug_install(struct ocfs2_blockcheck_stats *stats,
301 						 struct dentry *parent)
302 {
303 	return 0;
304 }
305 
ocfs2_blockcheck_debug_remove(struct ocfs2_blockcheck_stats * stats)306 static inline void ocfs2_blockcheck_debug_remove(struct ocfs2_blockcheck_stats *stats)
307 {
308 }
309 #endif  /* CONFIG_DEBUG_FS */
310 
311 /* Always-called wrappers for starting and stopping the debugfs files */
ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats * stats,struct dentry * parent)312 int ocfs2_blockcheck_stats_debugfs_install(struct ocfs2_blockcheck_stats *stats,
313 					   struct dentry *parent)
314 {
315 	return ocfs2_blockcheck_debug_install(stats, parent);
316 }
317 
ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats * stats)318 void ocfs2_blockcheck_stats_debugfs_remove(struct ocfs2_blockcheck_stats *stats)
319 {
320 	ocfs2_blockcheck_debug_remove(stats);
321 }
322 
ocfs2_blockcheck_inc_check(struct ocfs2_blockcheck_stats * stats)323 static void ocfs2_blockcheck_inc_check(struct ocfs2_blockcheck_stats *stats)
324 {
325 	u64 new_count;
326 
327 	if (!stats)
328 		return;
329 
330 	spin_lock(&stats->b_lock);
331 	stats->b_check_count++;
332 	new_count = stats->b_check_count;
333 	spin_unlock(&stats->b_lock);
334 
335 	if (!new_count)
336 		mlog(ML_NOTICE, "Block check count has wrapped\n");
337 }
338 
ocfs2_blockcheck_inc_failure(struct ocfs2_blockcheck_stats * stats)339 static void ocfs2_blockcheck_inc_failure(struct ocfs2_blockcheck_stats *stats)
340 {
341 	u64 new_count;
342 
343 	if (!stats)
344 		return;
345 
346 	spin_lock(&stats->b_lock);
347 	stats->b_failure_count++;
348 	new_count = stats->b_failure_count;
349 	spin_unlock(&stats->b_lock);
350 
351 	if (!new_count)
352 		mlog(ML_NOTICE, "Checksum failure count has wrapped\n");
353 }
354 
ocfs2_blockcheck_inc_recover(struct ocfs2_blockcheck_stats * stats)355 static void ocfs2_blockcheck_inc_recover(struct ocfs2_blockcheck_stats *stats)
356 {
357 	u64 new_count;
358 
359 	if (!stats)
360 		return;
361 
362 	spin_lock(&stats->b_lock);
363 	stats->b_recover_count++;
364 	new_count = stats->b_recover_count;
365 	spin_unlock(&stats->b_lock);
366 
367 	if (!new_count)
368 		mlog(ML_NOTICE, "ECC recovery count has wrapped\n");
369 }
370 
371 
372 
373 /*
374  * These are the low-level APIs for using the ocfs2_block_check structure.
375  */
376 
377 /*
378  * This function generates check information for a block.
379  * data is the block to be checked.  bc is a pointer to the
380  * ocfs2_block_check structure describing the crc32 and the ecc.
381  *
382  * bc should be a pointer inside data, as the function will
383  * take care of zeroing it before calculating the check information.  If
384  * bc does not point inside data, the caller must make sure any inline
385  * ocfs2_block_check structures are zeroed.
386  *
387  * The data buffer must be in on-disk endian (little endian for ocfs2).
388  * bc will be filled with little-endian values and will be ready to go to
389  * disk.
390  */
ocfs2_block_check_compute(void * data,size_t blocksize,struct ocfs2_block_check * bc)391 void ocfs2_block_check_compute(void *data, size_t blocksize,
392 			       struct ocfs2_block_check *bc)
393 {
394 	u32 crc;
395 	u32 ecc;
396 
397 	memset(bc, 0, sizeof(struct ocfs2_block_check));
398 
399 	crc = crc32_le(~0, data, blocksize);
400 	ecc = ocfs2_hamming_encode_block(data, blocksize);
401 
402 	/*
403 	 * No ecc'd ocfs2 structure is larger than 4K, so ecc will be no
404 	 * larger than 16 bits.
405 	 */
406 	BUG_ON(ecc > USHRT_MAX);
407 
408 	bc->bc_crc32e = cpu_to_le32(crc);
409 	bc->bc_ecc = cpu_to_le16((u16)ecc);
410 }
411 
412 /*
413  * This function validates existing check information.  Like _compute,
414  * the function will take care of zeroing bc before calculating check codes.
415  * If bc is not a pointer inside data, the caller must have zeroed any
416  * inline ocfs2_block_check structures.
417  *
418  * Again, the data passed in should be the on-disk endian.
419  */
ocfs2_block_check_validate(void * data,size_t blocksize,struct ocfs2_block_check * bc,struct ocfs2_blockcheck_stats * stats)420 int ocfs2_block_check_validate(void *data, size_t blocksize,
421 			       struct ocfs2_block_check *bc,
422 			       struct ocfs2_blockcheck_stats *stats)
423 {
424 	int rc = 0;
425 	struct ocfs2_block_check check;
426 	u32 crc, ecc;
427 
428 	ocfs2_blockcheck_inc_check(stats);
429 
430 	check.bc_crc32e = le32_to_cpu(bc->bc_crc32e);
431 	check.bc_ecc = le16_to_cpu(bc->bc_ecc);
432 
433 	memset(bc, 0, sizeof(struct ocfs2_block_check));
434 
435 	/* Fast path - if the crc32 validates, we're good to go */
436 	crc = crc32_le(~0, data, blocksize);
437 	if (crc == check.bc_crc32e)
438 		goto out;
439 
440 	ocfs2_blockcheck_inc_failure(stats);
441 	mlog(ML_ERROR,
442 	     "CRC32 failed: stored: 0x%x, computed 0x%x. Applying ECC.\n",
443 	     (unsigned int)check.bc_crc32e, (unsigned int)crc);
444 
445 	/* Ok, try ECC fixups */
446 	ecc = ocfs2_hamming_encode_block(data, blocksize);
447 	ocfs2_hamming_fix_block(data, blocksize, ecc ^ check.bc_ecc);
448 
449 	/* And check the crc32 again */
450 	crc = crc32_le(~0, data, blocksize);
451 	if (crc == check.bc_crc32e) {
452 		ocfs2_blockcheck_inc_recover(stats);
453 		goto out;
454 	}
455 
456 	mlog(ML_ERROR, "Fixed CRC32 failed: stored: 0x%x, computed 0x%x\n",
457 	     (unsigned int)check.bc_crc32e, (unsigned int)crc);
458 
459 	rc = -EIO;
460 
461 out:
462 	bc->bc_crc32e = cpu_to_le32(check.bc_crc32e);
463 	bc->bc_ecc = cpu_to_le16(check.bc_ecc);
464 
465 	return rc;
466 }
467 
468 /*
469  * This function generates check information for a list of buffer_heads.
470  * bhs is the blocks to be checked.  bc is a pointer to the
471  * ocfs2_block_check structure describing the crc32 and the ecc.
472  *
473  * bc should be a pointer inside data, as the function will
474  * take care of zeroing it before calculating the check information.  If
475  * bc does not point inside data, the caller must make sure any inline
476  * ocfs2_block_check structures are zeroed.
477  *
478  * The data buffer must be in on-disk endian (little endian for ocfs2).
479  * bc will be filled with little-endian values and will be ready to go to
480  * disk.
481  */
ocfs2_block_check_compute_bhs(struct buffer_head ** bhs,int nr,struct ocfs2_block_check * bc)482 void ocfs2_block_check_compute_bhs(struct buffer_head **bhs, int nr,
483 				   struct ocfs2_block_check *bc)
484 {
485 	int i;
486 	u32 crc, ecc;
487 
488 	BUG_ON(nr < 0);
489 
490 	if (!nr)
491 		return;
492 
493 	memset(bc, 0, sizeof(struct ocfs2_block_check));
494 
495 	for (i = 0, crc = ~0, ecc = 0; i < nr; i++) {
496 		crc = crc32_le(crc, bhs[i]->b_data, bhs[i]->b_size);
497 		/*
498 		 * The number of bits in a buffer is obviously b_size*8.
499 		 * The offset of this buffer is b_size*i, so the bit offset
500 		 * of this buffer is b_size*8*i.
501 		 */
502 		ecc = (u16)ocfs2_hamming_encode(ecc, bhs[i]->b_data,
503 						bhs[i]->b_size * 8,
504 						bhs[i]->b_size * 8 * i);
505 	}
506 
507 	/*
508 	 * No ecc'd ocfs2 structure is larger than 4K, so ecc will be no
509 	 * larger than 16 bits.
510 	 */
511 	BUG_ON(ecc > USHRT_MAX);
512 
513 	bc->bc_crc32e = cpu_to_le32(crc);
514 	bc->bc_ecc = cpu_to_le16((u16)ecc);
515 }
516 
517 /*
518  * This function validates existing check information on a list of
519  * buffer_heads.  Like _compute_bhs, the function will take care of
520  * zeroing bc before calculating check codes.  If bc is not a pointer
521  * inside data, the caller must have zeroed any inline
522  * ocfs2_block_check structures.
523  *
524  * Again, the data passed in should be the on-disk endian.
525  */
ocfs2_block_check_validate_bhs(struct buffer_head ** bhs,int nr,struct ocfs2_block_check * bc,struct ocfs2_blockcheck_stats * stats)526 int ocfs2_block_check_validate_bhs(struct buffer_head **bhs, int nr,
527 				   struct ocfs2_block_check *bc,
528 				   struct ocfs2_blockcheck_stats *stats)
529 {
530 	int i, rc = 0;
531 	struct ocfs2_block_check check;
532 	u32 crc, ecc, fix;
533 
534 	BUG_ON(nr < 0);
535 
536 	if (!nr)
537 		return 0;
538 
539 	ocfs2_blockcheck_inc_check(stats);
540 
541 	check.bc_crc32e = le32_to_cpu(bc->bc_crc32e);
542 	check.bc_ecc = le16_to_cpu(bc->bc_ecc);
543 
544 	memset(bc, 0, sizeof(struct ocfs2_block_check));
545 
546 	/* Fast path - if the crc32 validates, we're good to go */
547 	for (i = 0, crc = ~0; i < nr; i++)
548 		crc = crc32_le(crc, bhs[i]->b_data, bhs[i]->b_size);
549 	if (crc == check.bc_crc32e)
550 		goto out;
551 
552 	ocfs2_blockcheck_inc_failure(stats);
553 	mlog(ML_ERROR,
554 	     "CRC32 failed: stored: %u, computed %u.  Applying ECC.\n",
555 	     (unsigned int)check.bc_crc32e, (unsigned int)crc);
556 
557 	/* Ok, try ECC fixups */
558 	for (i = 0, ecc = 0; i < nr; i++) {
559 		/*
560 		 * The number of bits in a buffer is obviously b_size*8.
561 		 * The offset of this buffer is b_size*i, so the bit offset
562 		 * of this buffer is b_size*8*i.
563 		 */
564 		ecc = (u16)ocfs2_hamming_encode(ecc, bhs[i]->b_data,
565 						bhs[i]->b_size * 8,
566 						bhs[i]->b_size * 8 * i);
567 	}
568 	fix = ecc ^ check.bc_ecc;
569 	for (i = 0; i < nr; i++) {
570 		/*
571 		 * Try the fix against each buffer.  It will only affect
572 		 * one of them.
573 		 */
574 		ocfs2_hamming_fix(bhs[i]->b_data, bhs[i]->b_size * 8,
575 				  bhs[i]->b_size * 8 * i, fix);
576 	}
577 
578 	/* And check the crc32 again */
579 	for (i = 0, crc = ~0; i < nr; i++)
580 		crc = crc32_le(crc, bhs[i]->b_data, bhs[i]->b_size);
581 	if (crc == check.bc_crc32e) {
582 		ocfs2_blockcheck_inc_recover(stats);
583 		goto out;
584 	}
585 
586 	mlog(ML_ERROR, "Fixed CRC32 failed: stored: %u, computed %u\n",
587 	     (unsigned int)check.bc_crc32e, (unsigned int)crc);
588 
589 	rc = -EIO;
590 
591 out:
592 	bc->bc_crc32e = cpu_to_le32(check.bc_crc32e);
593 	bc->bc_ecc = cpu_to_le16(check.bc_ecc);
594 
595 	return rc;
596 }
597 
598 /*
599  * These are the main API.  They check the superblock flag before
600  * calling the underlying operations.
601  *
602  * They expect the buffer(s) to be in disk format.
603  */
ocfs2_compute_meta_ecc(struct super_block * sb,void * data,struct ocfs2_block_check * bc)604 void ocfs2_compute_meta_ecc(struct super_block *sb, void *data,
605 			    struct ocfs2_block_check *bc)
606 {
607 	if (ocfs2_meta_ecc(OCFS2_SB(sb)))
608 		ocfs2_block_check_compute(data, sb->s_blocksize, bc);
609 }
610 
ocfs2_validate_meta_ecc(struct super_block * sb,void * data,struct ocfs2_block_check * bc)611 int ocfs2_validate_meta_ecc(struct super_block *sb, void *data,
612 			    struct ocfs2_block_check *bc)
613 {
614 	int rc = 0;
615 	struct ocfs2_super *osb = OCFS2_SB(sb);
616 
617 	if (ocfs2_meta_ecc(osb))
618 		rc = ocfs2_block_check_validate(data, sb->s_blocksize, bc,
619 						&osb->osb_ecc_stats);
620 
621 	return rc;
622 }
623 
ocfs2_compute_meta_ecc_bhs(struct super_block * sb,struct buffer_head ** bhs,int nr,struct ocfs2_block_check * bc)624 void ocfs2_compute_meta_ecc_bhs(struct super_block *sb,
625 				struct buffer_head **bhs, int nr,
626 				struct ocfs2_block_check *bc)
627 {
628 	if (ocfs2_meta_ecc(OCFS2_SB(sb)))
629 		ocfs2_block_check_compute_bhs(bhs, nr, bc);
630 }
631 
ocfs2_validate_meta_ecc_bhs(struct super_block * sb,struct buffer_head ** bhs,int nr,struct ocfs2_block_check * bc)632 int ocfs2_validate_meta_ecc_bhs(struct super_block *sb,
633 				struct buffer_head **bhs, int nr,
634 				struct ocfs2_block_check *bc)
635 {
636 	int rc = 0;
637 	struct ocfs2_super *osb = OCFS2_SB(sb);
638 
639 	if (ocfs2_meta_ecc(osb))
640 		rc = ocfs2_block_check_validate_bhs(bhs, nr, bc,
641 						    &osb->osb_ecc_stats);
642 
643 	return rc;
644 }
645 
646