xref: /linux/fs/xfs/libxfs/xfs_sb.c (revision 7a5f93ea5862da91488975acaa0c7abd508f192b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_bit.h"
13 #include "xfs_sb.h"
14 #include "xfs_mount.h"
15 #include "xfs_ialloc.h"
16 #include "xfs_alloc.h"
17 #include "xfs_error.h"
18 #include "xfs_trans.h"
19 #include "xfs_buf_item.h"
20 #include "xfs_bmap_btree.h"
21 #include "xfs_alloc_btree.h"
22 #include "xfs_log.h"
23 #include "xfs_rmap_btree.h"
24 #include "xfs_refcount_btree.h"
25 #include "xfs_da_format.h"
26 #include "xfs_health.h"
27 #include "xfs_ag.h"
28 #include "xfs_rtbitmap.h"
29 #include "xfs_exchrange.h"
30 #include "xfs_rtgroup.h"
31 
32 /*
33  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
34  */
35 
36 /*
37  * Check that all the V4 feature bits that the V5 filesystem format requires are
38  * correctly set.
39  */
40 static bool
41 xfs_sb_validate_v5_features(
42 	struct xfs_sb	*sbp)
43 {
44 	/* We must not have any unknown V4 feature bits set */
45 	if (sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS)
46 		return false;
47 
48 	/*
49 	 * The CRC bit is considered an invalid V4 flag, so we have to add it
50 	 * manually to the OKBITS mask.
51 	 */
52 	if (sbp->sb_features2 & ~(XFS_SB_VERSION2_OKBITS |
53 				  XFS_SB_VERSION2_CRCBIT))
54 		return false;
55 
56 	/* Now check all the required V4 feature flags are set. */
57 
58 #define V5_VERS_FLAGS	(XFS_SB_VERSION_NLINKBIT	| \
59 			XFS_SB_VERSION_ALIGNBIT		| \
60 			XFS_SB_VERSION_LOGV2BIT		| \
61 			XFS_SB_VERSION_EXTFLGBIT	| \
62 			XFS_SB_VERSION_DIRV2BIT		| \
63 			XFS_SB_VERSION_MOREBITSBIT)
64 
65 #define V5_FEAT_FLAGS	(XFS_SB_VERSION2_LAZYSBCOUNTBIT	| \
66 			XFS_SB_VERSION2_ATTR2BIT	| \
67 			XFS_SB_VERSION2_PROJID32BIT	| \
68 			XFS_SB_VERSION2_CRCBIT)
69 
70 	if ((sbp->sb_versionnum & V5_VERS_FLAGS) != V5_VERS_FLAGS)
71 		return false;
72 	if ((sbp->sb_features2 & V5_FEAT_FLAGS) != V5_FEAT_FLAGS)
73 		return false;
74 	return true;
75 }
76 
77 /*
78  * We current support XFS v5 formats with known features and v4 superblocks with
79  * at least V2 directories.
80  */
81 bool
82 xfs_sb_good_version(
83 	struct xfs_sb	*sbp)
84 {
85 	/*
86 	 * All v5 filesystems are supported, but we must check that all the
87 	 * required v4 feature flags are enabled correctly as the code checks
88 	 * those flags and not for v5 support.
89 	 */
90 	if (xfs_sb_is_v5(sbp))
91 		return xfs_sb_validate_v5_features(sbp);
92 
93 	/* versions prior to v4 are not supported */
94 	if (XFS_SB_VERSION_NUM(sbp) != XFS_SB_VERSION_4)
95 		return false;
96 
97 	/* We must not have any unknown v4 feature bits set */
98 	if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
99 	    ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
100 	     (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS)))
101 		return false;
102 
103 	/* V4 filesystems need v2 directories and unwritten extents */
104 	if (!(sbp->sb_versionnum & XFS_SB_VERSION_DIRV2BIT))
105 		return false;
106 	if (!(sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT))
107 		return false;
108 
109 	/* It's a supported v4 filesystem */
110 	return true;
111 }
112 
113 uint64_t
114 xfs_sb_version_to_features(
115 	struct xfs_sb	*sbp)
116 {
117 	uint64_t	features = 0;
118 
119 	/* optional V4 features */
120 	if (sbp->sb_rblocks > 0)
121 		features |= XFS_FEAT_REALTIME;
122 	if (sbp->sb_versionnum & XFS_SB_VERSION_NLINKBIT)
123 		features |= XFS_FEAT_NLINK;
124 	if (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT)
125 		features |= XFS_FEAT_ATTR;
126 	if (sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT)
127 		features |= XFS_FEAT_QUOTA;
128 	if (sbp->sb_versionnum & XFS_SB_VERSION_ALIGNBIT)
129 		features |= XFS_FEAT_ALIGN;
130 	if (sbp->sb_versionnum & XFS_SB_VERSION_LOGV2BIT)
131 		features |= XFS_FEAT_LOGV2;
132 	if (sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT)
133 		features |= XFS_FEAT_DALIGN;
134 	if (sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT)
135 		features |= XFS_FEAT_EXTFLG;
136 	if (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT)
137 		features |= XFS_FEAT_SECTOR;
138 	if (sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT)
139 		features |= XFS_FEAT_ASCIICI;
140 	if (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) {
141 		if (sbp->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT)
142 			features |= XFS_FEAT_LAZYSBCOUNT;
143 		if (sbp->sb_features2 & XFS_SB_VERSION2_ATTR2BIT)
144 			features |= XFS_FEAT_ATTR2;
145 		if (sbp->sb_features2 & XFS_SB_VERSION2_PROJID32BIT)
146 			features |= XFS_FEAT_PROJID32;
147 		if (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE)
148 			features |= XFS_FEAT_FTYPE;
149 	}
150 
151 	if (!xfs_sb_is_v5(sbp))
152 		return features;
153 
154 	/* Always on V5 features */
155 	features |= XFS_FEAT_ALIGN | XFS_FEAT_LOGV2 | XFS_FEAT_EXTFLG |
156 		    XFS_FEAT_LAZYSBCOUNT | XFS_FEAT_ATTR2 | XFS_FEAT_PROJID32 |
157 		    XFS_FEAT_V3INODES | XFS_FEAT_CRC | XFS_FEAT_PQUOTINO;
158 
159 	/* Optional V5 features */
160 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT)
161 		features |= XFS_FEAT_FINOBT;
162 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT)
163 		features |= XFS_FEAT_RMAPBT;
164 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_REFLINK)
165 		features |= XFS_FEAT_REFLINK;
166 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_INOBTCNT)
167 		features |= XFS_FEAT_INOBTCNT;
168 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_FTYPE)
169 		features |= XFS_FEAT_FTYPE;
170 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES)
171 		features |= XFS_FEAT_SPINODES;
172 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
173 		features |= XFS_FEAT_META_UUID;
174 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_BIGTIME)
175 		features |= XFS_FEAT_BIGTIME;
176 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
177 		features |= XFS_FEAT_NEEDSREPAIR;
178 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
179 		features |= XFS_FEAT_NREXT64;
180 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_EXCHRANGE)
181 		features |= XFS_FEAT_EXCHANGE_RANGE;
182 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_PARENT)
183 		features |= XFS_FEAT_PARENT;
184 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR)
185 		features |= XFS_FEAT_METADIR;
186 
187 	return features;
188 }
189 
190 /* Check all the superblock fields we care about when reading one in. */
191 STATIC int
192 xfs_validate_sb_read(
193 	struct xfs_mount	*mp,
194 	struct xfs_sb		*sbp)
195 {
196 	if (!xfs_sb_is_v5(sbp))
197 		return 0;
198 
199 	/*
200 	 * Version 5 superblock feature mask validation. Reject combinations
201 	 * the kernel cannot support up front before checking anything else.
202 	 */
203 	if (xfs_sb_has_compat_feature(sbp, XFS_SB_FEAT_COMPAT_UNKNOWN)) {
204 		xfs_warn(mp,
205 "Superblock has unknown compatible features (0x%x) enabled.",
206 			(sbp->sb_features_compat & XFS_SB_FEAT_COMPAT_UNKNOWN));
207 		xfs_warn(mp,
208 "Using a more recent kernel is recommended.");
209 	}
210 
211 	if (xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
212 		xfs_alert(mp,
213 "Superblock has unknown read-only compatible features (0x%x) enabled.",
214 			(sbp->sb_features_ro_compat &
215 					XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
216 		if (!xfs_is_readonly(mp)) {
217 			xfs_warn(mp,
218 "Attempted to mount read-only compatible filesystem read-write.");
219 			xfs_warn(mp,
220 "Filesystem can only be safely mounted read only.");
221 
222 			return -EINVAL;
223 		}
224 	}
225 	if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
226 		xfs_warn(mp,
227 "Superblock has unknown incompatible features (0x%x) enabled.",
228 			(sbp->sb_features_incompat &
229 					XFS_SB_FEAT_INCOMPAT_UNKNOWN));
230 		xfs_warn(mp,
231 "Filesystem cannot be safely mounted by this kernel.");
232 		return -EINVAL;
233 	}
234 
235 	return 0;
236 }
237 
238 /* Return the number of extents covered by a single rt bitmap file */
239 static xfs_rtbxlen_t
240 xfs_extents_per_rbm(
241 	struct xfs_sb		*sbp)
242 {
243 	if (xfs_sb_is_v5(sbp) &&
244 	    (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR))
245 		return sbp->sb_rgextents;
246 	return sbp->sb_rextents;
247 }
248 
249 /*
250  * Return the payload size of a single rt bitmap block (without the metadata
251  * header if any).
252  */
253 static inline unsigned int
254 xfs_rtbmblock_size(
255 	struct xfs_sb		*sbp)
256 {
257 	if (xfs_sb_is_v5(sbp) &&
258 	    (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR))
259 		return sbp->sb_blocksize - sizeof(struct xfs_rtbuf_blkinfo);
260 	return sbp->sb_blocksize;
261 }
262 
263 static uint64_t
264 xfs_expected_rbmblocks(
265 	struct xfs_sb		*sbp)
266 {
267 	return howmany_64(xfs_extents_per_rbm(sbp),
268 			  NBBY * xfs_rtbmblock_size(sbp));
269 }
270 
271 /* Validate the realtime geometry */
272 bool
273 xfs_validate_rt_geometry(
274 	struct xfs_sb		*sbp)
275 {
276 	if (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE ||
277 	    sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)
278 		return false;
279 
280 	if (sbp->sb_rblocks == 0) {
281 		if (sbp->sb_rextents != 0 || sbp->sb_rbmblocks != 0 ||
282 		    sbp->sb_rextslog != 0 || sbp->sb_frextents != 0)
283 			return false;
284 		return true;
285 	}
286 
287 	if (sbp->sb_rextents == 0 ||
288 	    sbp->sb_rextents != div_u64(sbp->sb_rblocks, sbp->sb_rextsize) ||
289 	    sbp->sb_rextslog != xfs_compute_rextslog(sbp->sb_rextents) ||
290 	    sbp->sb_rbmblocks != xfs_expected_rbmblocks(sbp))
291 		return false;
292 
293 	return true;
294 }
295 
296 /* Check all the superblock fields we care about when writing one out. */
297 STATIC int
298 xfs_validate_sb_write(
299 	struct xfs_mount	*mp,
300 	struct xfs_buf		*bp,
301 	struct xfs_sb		*sbp)
302 {
303 	/*
304 	 * Carry out additional sb summary counter sanity checks when we write
305 	 * the superblock.  We skip this in the read validator because there
306 	 * could be newer superblocks in the log and if the values are garbage
307 	 * even after replay we'll recalculate them at the end of log mount.
308 	 *
309 	 * mkfs has traditionally written zeroed counters to inprogress and
310 	 * secondary superblocks, so allow this usage to continue because
311 	 * we never read counters from such superblocks.
312 	 */
313 	if (xfs_buf_daddr(bp) == XFS_SB_DADDR && !sbp->sb_inprogress &&
314 	    (sbp->sb_fdblocks > sbp->sb_dblocks ||
315 	     !xfs_verify_icount(mp, sbp->sb_icount) ||
316 	     sbp->sb_ifree > sbp->sb_icount)) {
317 		xfs_warn(mp, "SB summary counter sanity check failed");
318 		return -EFSCORRUPTED;
319 	}
320 
321 	if (!xfs_sb_is_v5(sbp))
322 		return 0;
323 
324 	/*
325 	 * Version 5 superblock feature mask validation. Reject combinations
326 	 * the kernel cannot support since we checked for unsupported bits in
327 	 * the read verifier, which means that memory is corrupt.
328 	 */
329 	if (!xfs_is_readonly(mp) &&
330 	    xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
331 		xfs_alert(mp,
332 "Corruption detected in superblock read-only compatible features (0x%x)!",
333 			(sbp->sb_features_ro_compat &
334 					XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
335 		return -EFSCORRUPTED;
336 	}
337 	if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
338 		xfs_warn(mp,
339 "Corruption detected in superblock incompatible features (0x%x)!",
340 			(sbp->sb_features_incompat &
341 					XFS_SB_FEAT_INCOMPAT_UNKNOWN));
342 		return -EFSCORRUPTED;
343 	}
344 	if (xfs_sb_has_incompat_log_feature(sbp,
345 			XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) {
346 		xfs_warn(mp,
347 "Corruption detected in superblock incompatible log features (0x%x)!",
348 			(sbp->sb_features_log_incompat &
349 					XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));
350 		return -EFSCORRUPTED;
351 	}
352 
353 	/*
354 	 * We can't read verify the sb LSN because the read verifier is called
355 	 * before the log is allocated and processed. We know the log is set up
356 	 * before write verifier calls, so check it here.
357 	 */
358 	if (!xfs_log_check_lsn(mp, sbp->sb_lsn))
359 		return -EFSCORRUPTED;
360 
361 	return 0;
362 }
363 
364 int
365 xfs_compute_rgblklog(
366 	xfs_rtxlen_t	rgextents,
367 	xfs_rgblock_t	rextsize)
368 {
369 	uint64_t	rgblocks = (uint64_t)rgextents * rextsize;
370 
371 	return xfs_highbit64(rgblocks - 1) + 1;
372 }
373 
374 static int
375 xfs_validate_sb_rtgroups(
376 	struct xfs_mount	*mp,
377 	struct xfs_sb		*sbp)
378 {
379 	uint64_t		groups;
380 	int			rgblklog;
381 
382 	if (sbp->sb_rextsize == 0) {
383 		xfs_warn(mp,
384 "Realtime extent size must not be zero.");
385 		return -EINVAL;
386 	}
387 
388 	if (sbp->sb_rgextents > XFS_MAX_RGBLOCKS / sbp->sb_rextsize) {
389 		xfs_warn(mp,
390 "Realtime group size (%u) must be less than %u rt extents.",
391 				sbp->sb_rgextents,
392 				XFS_MAX_RGBLOCKS / sbp->sb_rextsize);
393 		return -EINVAL;
394 	}
395 
396 	if (sbp->sb_rgextents < XFS_MIN_RGEXTENTS) {
397 		xfs_warn(mp,
398 "Realtime group size (%u) must be at least %u rt extents.",
399 				sbp->sb_rgextents, XFS_MIN_RGEXTENTS);
400 		return -EINVAL;
401 	}
402 
403 	if (sbp->sb_rgcount > XFS_MAX_RGNUMBER) {
404 		xfs_warn(mp,
405 "Realtime groups (%u) must be less than %u.",
406 				sbp->sb_rgcount, XFS_MAX_RGNUMBER);
407 		return -EINVAL;
408 	}
409 
410 	groups = howmany_64(sbp->sb_rextents, sbp->sb_rgextents);
411 	if (groups != sbp->sb_rgcount) {
412 		xfs_warn(mp,
413 "Realtime groups (%u) do not cover the entire rt section; need (%llu) groups.",
414 				sbp->sb_rgcount, groups);
415 		return -EINVAL;
416 	}
417 
418 	/* Exchange-range is required for fsr to work on realtime files */
419 	if (!(sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_EXCHRANGE)) {
420 		xfs_warn(mp,
421 "Realtime groups feature requires exchange-range support.");
422 		return -EINVAL;
423 	}
424 
425 	rgblklog = xfs_compute_rgblklog(sbp->sb_rgextents, sbp->sb_rextsize);
426 	if (sbp->sb_rgblklog != rgblklog) {
427 		xfs_warn(mp,
428 "Realtime group log (%d) does not match expected value (%d).",
429 				sbp->sb_rgblklog, rgblklog);
430 		return -EINVAL;
431 	}
432 
433 	return 0;
434 }
435 
436 /* Check the validity of the SB. */
437 STATIC int
438 xfs_validate_sb_common(
439 	struct xfs_mount	*mp,
440 	struct xfs_buf		*bp,
441 	struct xfs_sb		*sbp)
442 {
443 	struct xfs_dsb		*dsb = bp->b_addr;
444 	uint32_t		agcount = 0;
445 	uint32_t		rem;
446 	bool			has_dalign;
447 	int			error;
448 
449 	if (!xfs_verify_magic(bp, dsb->sb_magicnum)) {
450 		xfs_warn(mp,
451 "Superblock has bad magic number 0x%x. Not an XFS filesystem?",
452 			be32_to_cpu(dsb->sb_magicnum));
453 		return -EWRONGFS;
454 	}
455 
456 	if (!xfs_sb_good_version(sbp)) {
457 		xfs_warn(mp,
458 "Superblock has unknown features enabled or corrupted feature masks.");
459 		return -EWRONGFS;
460 	}
461 
462 	/*
463 	 * Validate feature flags and state
464 	 */
465 	if (xfs_sb_is_v5(sbp)) {
466 		if (sbp->sb_blocksize < XFS_MIN_CRC_BLOCKSIZE) {
467 			xfs_notice(mp,
468 "Block size (%u bytes) too small for Version 5 superblock (minimum %d bytes)",
469 				sbp->sb_blocksize, XFS_MIN_CRC_BLOCKSIZE);
470 			return -EFSCORRUPTED;
471 		}
472 
473 		/* V5 has a separate project quota inode */
474 		if (sbp->sb_qflags & (XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD)) {
475 			xfs_notice(mp,
476 			   "Version 5 of Super block has XFS_OQUOTA bits.");
477 			return -EFSCORRUPTED;
478 		}
479 
480 		/*
481 		 * Full inode chunks must be aligned to inode chunk size when
482 		 * sparse inodes are enabled to support the sparse chunk
483 		 * allocation algorithm and prevent overlapping inode records.
484 		 */
485 		if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES) {
486 			uint32_t	align;
487 
488 			align = XFS_INODES_PER_CHUNK * sbp->sb_inodesize
489 					>> sbp->sb_blocklog;
490 			if (sbp->sb_inoalignmt != align) {
491 				xfs_warn(mp,
492 "Inode block alignment (%u) must match chunk size (%u) for sparse inodes.",
493 					 sbp->sb_inoalignmt, align);
494 				return -EINVAL;
495 			}
496 
497 			if (!sbp->sb_spino_align ||
498 			    sbp->sb_spino_align > sbp->sb_inoalignmt ||
499 			    (sbp->sb_inoalignmt % sbp->sb_spino_align) != 0) {
500 				xfs_warn(mp,
501 				"Sparse inode alignment (%u) is invalid.",
502 					sbp->sb_spino_align);
503 				return -EINVAL;
504 			}
505 		} else if (sbp->sb_spino_align) {
506 			xfs_warn(mp,
507 				"Sparse inode alignment (%u) should be zero.",
508 				sbp->sb_spino_align);
509 			return -EINVAL;
510 		}
511 
512 		if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR) {
513 			if (memchr_inv(sbp->sb_pad, 0, sizeof(sbp->sb_pad))) {
514 				xfs_warn(mp,
515 "Metadir superblock padding fields must be zero.");
516 				return -EINVAL;
517 			}
518 
519 			error = xfs_validate_sb_rtgroups(mp, sbp);
520 			if (error)
521 				return error;
522 		}
523 	} else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
524 				XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
525 			xfs_notice(mp,
526 "Superblock earlier than Version 5 has XFS_{P|G}QUOTA_{ENFD|CHKD} bits.");
527 			return -EFSCORRUPTED;
528 	}
529 
530 	if (unlikely(
531 	    sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
532 		xfs_warn(mp,
533 		"filesystem is marked as having an external log; "
534 		"specify logdev on the mount command line.");
535 		return -EINVAL;
536 	}
537 
538 	if (unlikely(
539 	    sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
540 		xfs_warn(mp,
541 		"filesystem is marked as having an internal log; "
542 		"do not specify logdev on the mount command line.");
543 		return -EINVAL;
544 	}
545 
546 	/* Compute agcount for this number of dblocks and agblocks */
547 	if (sbp->sb_agblocks) {
548 		agcount = div_u64_rem(sbp->sb_dblocks, sbp->sb_agblocks, &rem);
549 		if (rem)
550 			agcount++;
551 	}
552 
553 	/*
554 	 * More sanity checking.  Most of these were stolen directly from
555 	 * xfs_repair.
556 	 */
557 	if (unlikely(
558 	    sbp->sb_agcount <= 0					||
559 	    sbp->sb_sectsize < XFS_MIN_SECTORSIZE			||
560 	    sbp->sb_sectsize > XFS_MAX_SECTORSIZE			||
561 	    sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG			||
562 	    sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG			||
563 	    sbp->sb_sectsize != (1 << sbp->sb_sectlog)			||
564 	    sbp->sb_blocksize < XFS_MIN_BLOCKSIZE			||
565 	    sbp->sb_blocksize > XFS_MAX_BLOCKSIZE			||
566 	    sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG			||
567 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
568 	    sbp->sb_blocksize != (1 << sbp->sb_blocklog)		||
569 	    sbp->sb_dirblklog + sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
570 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
571 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
572 	    sbp->sb_inodelog < XFS_DINODE_MIN_LOG			||
573 	    sbp->sb_inodelog > XFS_DINODE_MAX_LOG			||
574 	    sbp->sb_inodesize != (1 << sbp->sb_inodelog)		||
575 	    sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
576 	    XFS_FSB_TO_B(mp, sbp->sb_agblocks) < XFS_MIN_AG_BYTES	||
577 	    XFS_FSB_TO_B(mp, sbp->sb_agblocks) > XFS_MAX_AG_BYTES	||
578 	    sbp->sb_agblklog != xfs_highbit32(sbp->sb_agblocks - 1) + 1	||
579 	    agcount == 0 || agcount != sbp->sb_agcount			||
580 	    (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)	||
581 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
582 	    (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)	||
583 	    (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)	||
584 	    sbp->sb_dblocks == 0					||
585 	    sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)			||
586 	    sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)			||
587 	    sbp->sb_shared_vn != 0)) {
588 		xfs_notice(mp, "SB sanity check failed");
589 		return -EFSCORRUPTED;
590 	}
591 
592 	/*
593 	 * Logs that are too large are not supported at all. Reject them
594 	 * outright. Logs that are too small are tolerated on v4 filesystems,
595 	 * but we can only check that when mounting the log. Hence we skip
596 	 * those checks here.
597 	 */
598 	if (sbp->sb_logblocks > XFS_MAX_LOG_BLOCKS) {
599 		xfs_notice(mp,
600 		"Log size 0x%x blocks too large, maximum size is 0x%llx blocks",
601 			 sbp->sb_logblocks, XFS_MAX_LOG_BLOCKS);
602 		return -EFSCORRUPTED;
603 	}
604 
605 	if (XFS_FSB_TO_B(mp, sbp->sb_logblocks) > XFS_MAX_LOG_BYTES) {
606 		xfs_warn(mp,
607 		"log size 0x%llx bytes too large, maximum size is 0x%llx bytes",
608 			 XFS_FSB_TO_B(mp, sbp->sb_logblocks),
609 			 XFS_MAX_LOG_BYTES);
610 		return -EFSCORRUPTED;
611 	}
612 
613 	/*
614 	 * Do not allow filesystems with corrupted log sector or stripe units to
615 	 * be mounted. We cannot safely size the iclogs or write to the log if
616 	 * the log stripe unit is not valid.
617 	 */
618 	if (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT) {
619 		if (sbp->sb_logsectsize != (1U << sbp->sb_logsectlog)) {
620 			xfs_notice(mp,
621 			"log sector size in bytes/log2 (0x%x/0x%x) must match",
622 				sbp->sb_logsectsize, 1U << sbp->sb_logsectlog);
623 			return -EFSCORRUPTED;
624 		}
625 	} else if (sbp->sb_logsectsize || sbp->sb_logsectlog) {
626 		xfs_notice(mp,
627 		"log sector size in bytes/log2 (0x%x/0x%x) are not zero",
628 			sbp->sb_logsectsize, sbp->sb_logsectlog);
629 		return -EFSCORRUPTED;
630 	}
631 
632 	if (sbp->sb_logsunit > 1) {
633 		if (sbp->sb_logsunit % sbp->sb_blocksize) {
634 			xfs_notice(mp,
635 		"log stripe unit 0x%x bytes must be a multiple of block size",
636 				sbp->sb_logsunit);
637 			return -EFSCORRUPTED;
638 		}
639 		if (sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE) {
640 			xfs_notice(mp,
641 		"log stripe unit 0x%x bytes over maximum size (0x%x bytes)",
642 				sbp->sb_logsunit, XLOG_MAX_RECORD_BSIZE);
643 			return -EFSCORRUPTED;
644 		}
645 	}
646 
647 	if (!xfs_validate_rt_geometry(sbp)) {
648 		xfs_notice(mp,
649 			"realtime %sgeometry check failed",
650 			sbp->sb_rblocks ? "" : "zeroed ");
651 		return -EFSCORRUPTED;
652 	}
653 
654 	/*
655 	 * Either (sb_unit and !hasdalign) or (!sb_unit and hasdalign)
656 	 * would imply the image is corrupted.
657 	 */
658 	has_dalign = sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT;
659 	if (!!sbp->sb_unit ^ has_dalign) {
660 		xfs_notice(mp, "SB stripe alignment sanity check failed");
661 		return -EFSCORRUPTED;
662 	}
663 
664 	if (!xfs_validate_stripe_geometry(mp, XFS_FSB_TO_B(mp, sbp->sb_unit),
665 			XFS_FSB_TO_B(mp, sbp->sb_width), 0,
666 			xfs_buf_daddr(bp) == XFS_SB_DADDR, false))
667 		return -EFSCORRUPTED;
668 
669 	/*
670 	 * Currently only very few inode sizes are supported.
671 	 */
672 	switch (sbp->sb_inodesize) {
673 	case 256:
674 	case 512:
675 	case 1024:
676 	case 2048:
677 		break;
678 	default:
679 		xfs_warn(mp, "inode size of %d bytes not supported",
680 				sbp->sb_inodesize);
681 		return -ENOSYS;
682 	}
683 
684 	return 0;
685 }
686 
687 void
688 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
689 {
690 	if (xfs_sb_is_v5(sbp) &&
691 	    (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR)) {
692 		sbp->sb_uquotino = NULLFSINO;
693 		sbp->sb_gquotino = NULLFSINO;
694 		sbp->sb_pquotino = NULLFSINO;
695 		return;
696 	}
697 
698 	/*
699 	 * older mkfs doesn't initialize quota inodes to NULLFSINO. This
700 	 * leads to in-core values having two different values for a quota
701 	 * inode to be invalid: 0 and NULLFSINO. Change it to a single value
702 	 * NULLFSINO.
703 	 *
704 	 * Note that this change affect only the in-core values. These
705 	 * values are not written back to disk unless any quota information
706 	 * is written to the disk. Even in that case, sb_pquotino field is
707 	 * not written to disk unless the superblock supports pquotino.
708 	 */
709 	if (sbp->sb_uquotino == 0)
710 		sbp->sb_uquotino = NULLFSINO;
711 	if (sbp->sb_gquotino == 0)
712 		sbp->sb_gquotino = NULLFSINO;
713 	if (sbp->sb_pquotino == 0)
714 		sbp->sb_pquotino = NULLFSINO;
715 
716 	/*
717 	 * We need to do these manipilations only if we are working
718 	 * with an older version of on-disk superblock.
719 	 */
720 	if (xfs_sb_is_v5(sbp))
721 		return;
722 
723 	if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
724 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
725 					XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
726 	if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
727 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
728 					XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
729 	sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
730 
731 	if (sbp->sb_qflags & XFS_PQUOTA_ACCT &&
732 	    sbp->sb_gquotino != NULLFSINO)  {
733 		/*
734 		 * In older version of superblock, on-disk superblock only
735 		 * has sb_gquotino, and in-core superblock has both sb_gquotino
736 		 * and sb_pquotino. But, only one of them is supported at any
737 		 * point of time. So, if PQUOTA is set in disk superblock,
738 		 * copy over sb_gquotino to sb_pquotino.  The NULLFSINO test
739 		 * above is to make sure we don't do this twice and wipe them
740 		 * both out!
741 		 */
742 		sbp->sb_pquotino = sbp->sb_gquotino;
743 		sbp->sb_gquotino = NULLFSINO;
744 	}
745 }
746 
747 static void
748 __xfs_sb_from_disk(
749 	struct xfs_sb	*to,
750 	struct xfs_dsb	*from,
751 	bool		convert_xquota)
752 {
753 	to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
754 	to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
755 	to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
756 	to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
757 	to->sb_rextents = be64_to_cpu(from->sb_rextents);
758 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
759 	to->sb_logstart = be64_to_cpu(from->sb_logstart);
760 	to->sb_rootino = be64_to_cpu(from->sb_rootino);
761 	to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
762 	to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
763 	to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
764 	to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
765 	to->sb_agcount = be32_to_cpu(from->sb_agcount);
766 	to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
767 	to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
768 	to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
769 	to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
770 	to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
771 	to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
772 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
773 	to->sb_blocklog = from->sb_blocklog;
774 	to->sb_sectlog = from->sb_sectlog;
775 	to->sb_inodelog = from->sb_inodelog;
776 	to->sb_inopblog = from->sb_inopblog;
777 	to->sb_agblklog = from->sb_agblklog;
778 	to->sb_rextslog = from->sb_rextslog;
779 	to->sb_inprogress = from->sb_inprogress;
780 	to->sb_imax_pct = from->sb_imax_pct;
781 	to->sb_icount = be64_to_cpu(from->sb_icount);
782 	to->sb_ifree = be64_to_cpu(from->sb_ifree);
783 	to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
784 	to->sb_frextents = be64_to_cpu(from->sb_frextents);
785 	to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
786 	to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
787 	to->sb_qflags = be16_to_cpu(from->sb_qflags);
788 	to->sb_flags = from->sb_flags;
789 	to->sb_shared_vn = from->sb_shared_vn;
790 	to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
791 	to->sb_unit = be32_to_cpu(from->sb_unit);
792 	to->sb_width = be32_to_cpu(from->sb_width);
793 	to->sb_dirblklog = from->sb_dirblklog;
794 	to->sb_logsectlog = from->sb_logsectlog;
795 	to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
796 	to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
797 	to->sb_features2 = be32_to_cpu(from->sb_features2);
798 	to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
799 	to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
800 	to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
801 	to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
802 	to->sb_features_log_incompat =
803 				be32_to_cpu(from->sb_features_log_incompat);
804 	/* crc is only used on disk, not in memory; just init to 0 here. */
805 	to->sb_crc = 0;
806 	to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
807 	to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
808 	to->sb_lsn = be64_to_cpu(from->sb_lsn);
809 	/*
810 	 * sb_meta_uuid is only on disk if it differs from sb_uuid and the
811 	 * feature flag is set; if not set we keep it only in memory.
812 	 */
813 	if (xfs_sb_is_v5(to) &&
814 	    (to->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID))
815 		uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
816 	else
817 		uuid_copy(&to->sb_meta_uuid, &from->sb_uuid);
818 	/* Convert on-disk flags to in-memory flags? */
819 	if (convert_xquota)
820 		xfs_sb_quota_from_disk(to);
821 
822 	if (to->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR) {
823 		to->sb_metadirino = be64_to_cpu(from->sb_metadirino);
824 		to->sb_rgblklog = from->sb_rgblklog;
825 		memcpy(to->sb_pad, from->sb_pad, sizeof(to->sb_pad));
826 		to->sb_rgcount = be32_to_cpu(from->sb_rgcount);
827 		to->sb_rgextents = be32_to_cpu(from->sb_rgextents);
828 		to->sb_rbmino = NULLFSINO;
829 		to->sb_rsumino = NULLFSINO;
830 	} else {
831 		to->sb_metadirino = NULLFSINO;
832 		to->sb_rgcount = 1;
833 		to->sb_rgextents = 0;
834 	}
835 }
836 
837 void
838 xfs_sb_from_disk(
839 	struct xfs_sb	*to,
840 	struct xfs_dsb	*from)
841 {
842 	__xfs_sb_from_disk(to, from, true);
843 }
844 
845 static void
846 xfs_sb_quota_to_disk(
847 	struct xfs_dsb	*to,
848 	struct xfs_sb	*from)
849 {
850 	uint16_t	qflags = from->sb_qflags;
851 
852 	if (xfs_sb_is_v5(from) &&
853 	    (from->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR)) {
854 		to->sb_qflags = cpu_to_be16(from->sb_qflags);
855 		to->sb_uquotino = cpu_to_be64(0);
856 		to->sb_gquotino = cpu_to_be64(0);
857 		to->sb_pquotino = cpu_to_be64(0);
858 		return;
859 	}
860 
861 	to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
862 
863 	/*
864 	 * The in-memory superblock quota state matches the v5 on-disk format so
865 	 * just write them out and return
866 	 */
867 	if (xfs_sb_is_v5(from)) {
868 		to->sb_qflags = cpu_to_be16(from->sb_qflags);
869 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
870 		to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
871 		return;
872 	}
873 
874 	/*
875 	 * For older superblocks (v4), the in-core version of sb_qflags do not
876 	 * have XFS_OQUOTA_* flags, whereas the on-disk version does.  So,
877 	 * convert incore XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
878 	 */
879 	qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
880 			XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
881 
882 	if (from->sb_qflags &
883 			(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
884 		qflags |= XFS_OQUOTA_ENFD;
885 	if (from->sb_qflags &
886 			(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
887 		qflags |= XFS_OQUOTA_CHKD;
888 	to->sb_qflags = cpu_to_be16(qflags);
889 
890 	/*
891 	 * GQUOTINO and PQUOTINO cannot be used together in versions
892 	 * of superblock that do not have pquotino. from->sb_flags
893 	 * tells us which quota is active and should be copied to
894 	 * disk. If neither are active, we should NULL the inode.
895 	 *
896 	 * In all cases, the separate pquotino must remain 0 because it
897 	 * is beyond the "end" of the valid non-pquotino superblock.
898 	 */
899 	if (from->sb_qflags & XFS_GQUOTA_ACCT)
900 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
901 	else if (from->sb_qflags & XFS_PQUOTA_ACCT)
902 		to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
903 	else {
904 		/*
905 		 * We can't rely on just the fields being logged to tell us
906 		 * that it is safe to write NULLFSINO - we should only do that
907 		 * if quotas are not actually enabled. Hence only write
908 		 * NULLFSINO if both in-core quota inodes are NULL.
909 		 */
910 		if (from->sb_gquotino == NULLFSINO &&
911 		    from->sb_pquotino == NULLFSINO)
912 			to->sb_gquotino = cpu_to_be64(NULLFSINO);
913 	}
914 
915 	to->sb_pquotino = 0;
916 }
917 
918 void
919 xfs_sb_to_disk(
920 	struct xfs_dsb	*to,
921 	struct xfs_sb	*from)
922 {
923 	xfs_sb_quota_to_disk(to, from);
924 
925 	to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
926 	to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
927 	to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
928 	to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
929 	to->sb_rextents = cpu_to_be64(from->sb_rextents);
930 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
931 	to->sb_logstart = cpu_to_be64(from->sb_logstart);
932 	to->sb_rootino = cpu_to_be64(from->sb_rootino);
933 	to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
934 	to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
935 	to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
936 	to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
937 	to->sb_agcount = cpu_to_be32(from->sb_agcount);
938 	to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
939 	to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
940 	to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
941 	to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
942 	to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
943 	to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
944 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
945 	to->sb_blocklog = from->sb_blocklog;
946 	to->sb_sectlog = from->sb_sectlog;
947 	to->sb_inodelog = from->sb_inodelog;
948 	to->sb_inopblog = from->sb_inopblog;
949 	to->sb_agblklog = from->sb_agblklog;
950 	to->sb_rextslog = from->sb_rextslog;
951 	to->sb_inprogress = from->sb_inprogress;
952 	to->sb_imax_pct = from->sb_imax_pct;
953 	to->sb_icount = cpu_to_be64(from->sb_icount);
954 	to->sb_ifree = cpu_to_be64(from->sb_ifree);
955 	to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
956 	to->sb_frextents = cpu_to_be64(from->sb_frextents);
957 
958 	to->sb_flags = from->sb_flags;
959 	to->sb_shared_vn = from->sb_shared_vn;
960 	to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
961 	to->sb_unit = cpu_to_be32(from->sb_unit);
962 	to->sb_width = cpu_to_be32(from->sb_width);
963 	to->sb_dirblklog = from->sb_dirblklog;
964 	to->sb_logsectlog = from->sb_logsectlog;
965 	to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
966 	to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
967 
968 	/*
969 	 * We need to ensure that bad_features2 always matches features2.
970 	 * Hence we enforce that here rather than having to remember to do it
971 	 * everywhere else that updates features2.
972 	 */
973 	from->sb_bad_features2 = from->sb_features2;
974 	to->sb_features2 = cpu_to_be32(from->sb_features2);
975 	to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
976 
977 	if (!xfs_sb_is_v5(from))
978 		return;
979 
980 	to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
981 	to->sb_features_ro_compat =
982 			cpu_to_be32(from->sb_features_ro_compat);
983 	to->sb_features_incompat =
984 			cpu_to_be32(from->sb_features_incompat);
985 	to->sb_features_log_incompat =
986 			cpu_to_be32(from->sb_features_log_incompat);
987 	to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
988 	to->sb_lsn = cpu_to_be64(from->sb_lsn);
989 	if (from->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
990 		uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
991 
992 	if (from->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR) {
993 		to->sb_metadirino = cpu_to_be64(from->sb_metadirino);
994 		to->sb_rgblklog = from->sb_rgblklog;
995 		memset(to->sb_pad, 0, sizeof(to->sb_pad));
996 		to->sb_rgcount = cpu_to_be32(from->sb_rgcount);
997 		to->sb_rgextents = cpu_to_be32(from->sb_rgextents);
998 		to->sb_rbmino = cpu_to_be64(0);
999 		to->sb_rsumino = cpu_to_be64(0);
1000 	}
1001 }
1002 
1003 /*
1004  * If the superblock has the CRC feature bit set or the CRC field is non-null,
1005  * check that the CRC is valid.  We check the CRC field is non-null because a
1006  * single bit error could clear the feature bit and unused parts of the
1007  * superblock are supposed to be zero. Hence a non-null crc field indicates that
1008  * we've potentially lost a feature bit and we should check it anyway.
1009  *
1010  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
1011  * last field in V4 secondary superblocks.  So for secondary superblocks,
1012  * we are more forgiving, and ignore CRC failures if the primary doesn't
1013  * indicate that the fs version is V5.
1014  */
1015 static void
1016 xfs_sb_read_verify(
1017 	struct xfs_buf		*bp)
1018 {
1019 	struct xfs_sb		sb;
1020 	struct xfs_mount	*mp = bp->b_mount;
1021 	struct xfs_dsb		*dsb = bp->b_addr;
1022 	int			error;
1023 
1024 	/*
1025 	 * open code the version check to avoid needing to convert the entire
1026 	 * superblock from disk order just to check the version number
1027 	 */
1028 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
1029 	    (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
1030 						XFS_SB_VERSION_5) ||
1031 	     dsb->sb_crc != 0)) {
1032 
1033 		if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
1034 			/* Only fail bad secondaries on a known V5 filesystem */
1035 			if (xfs_buf_daddr(bp) == XFS_SB_DADDR ||
1036 			    xfs_has_crc(mp)) {
1037 				error = -EFSBADCRC;
1038 				goto out_error;
1039 			}
1040 		}
1041 	}
1042 
1043 	/*
1044 	 * Check all the superblock fields.  Don't byteswap the xquota flags
1045 	 * because _verify_common checks the on-disk values.
1046 	 */
1047 	__xfs_sb_from_disk(&sb, dsb, false);
1048 	error = xfs_validate_sb_common(mp, bp, &sb);
1049 	if (error)
1050 		goto out_error;
1051 	error = xfs_validate_sb_read(mp, &sb);
1052 
1053 out_error:
1054 	if (error == -EFSCORRUPTED || error == -EFSBADCRC)
1055 		xfs_verifier_error(bp, error, __this_address);
1056 	else if (error)
1057 		xfs_buf_ioerror(bp, error);
1058 }
1059 
1060 /*
1061  * We may be probed for a filesystem match, so we may not want to emit
1062  * messages when the superblock buffer is not actually an XFS superblock.
1063  * If we find an XFS superblock, then run a normal, noisy mount because we are
1064  * really going to mount it and want to know about errors.
1065  */
1066 static void
1067 xfs_sb_quiet_read_verify(
1068 	struct xfs_buf	*bp)
1069 {
1070 	struct xfs_dsb	*dsb = bp->b_addr;
1071 
1072 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
1073 		/* XFS filesystem, verify noisily! */
1074 		xfs_sb_read_verify(bp);
1075 		return;
1076 	}
1077 	/* quietly fail */
1078 	xfs_buf_ioerror(bp, -EWRONGFS);
1079 }
1080 
1081 static void
1082 xfs_sb_write_verify(
1083 	struct xfs_buf		*bp)
1084 {
1085 	struct xfs_sb		sb;
1086 	struct xfs_mount	*mp = bp->b_mount;
1087 	struct xfs_buf_log_item	*bip = bp->b_log_item;
1088 	struct xfs_dsb		*dsb = bp->b_addr;
1089 	int			error;
1090 
1091 	/*
1092 	 * Check all the superblock fields.  Don't byteswap the xquota flags
1093 	 * because _verify_common checks the on-disk values.
1094 	 */
1095 	__xfs_sb_from_disk(&sb, dsb, false);
1096 	error = xfs_validate_sb_common(mp, bp, &sb);
1097 	if (error)
1098 		goto out_error;
1099 	error = xfs_validate_sb_write(mp, bp, &sb);
1100 	if (error)
1101 		goto out_error;
1102 
1103 	if (!xfs_sb_is_v5(&sb))
1104 		return;
1105 
1106 	if (bip)
1107 		dsb->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
1108 
1109 	xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
1110 	return;
1111 
1112 out_error:
1113 	xfs_verifier_error(bp, error, __this_address);
1114 }
1115 
1116 const struct xfs_buf_ops xfs_sb_buf_ops = {
1117 	.name = "xfs_sb",
1118 	.magic = { cpu_to_be32(XFS_SB_MAGIC), cpu_to_be32(XFS_SB_MAGIC) },
1119 	.verify_read = xfs_sb_read_verify,
1120 	.verify_write = xfs_sb_write_verify,
1121 };
1122 
1123 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
1124 	.name = "xfs_sb_quiet",
1125 	.magic = { cpu_to_be32(XFS_SB_MAGIC), cpu_to_be32(XFS_SB_MAGIC) },
1126 	.verify_read = xfs_sb_quiet_read_verify,
1127 	.verify_write = xfs_sb_write_verify,
1128 };
1129 
1130 /* Compute cached rt geometry from the incore sb. */
1131 void
1132 xfs_sb_mount_rextsize(
1133 	struct xfs_mount	*mp,
1134 	struct xfs_sb		*sbp)
1135 {
1136 	struct xfs_groups	*rgs = &mp->m_groups[XG_TYPE_RTG];
1137 
1138 	mp->m_rtxblklog = log2_if_power2(sbp->sb_rextsize);
1139 	mp->m_rtxblkmask = mask64_if_power2(sbp->sb_rextsize);
1140 
1141 	if (xfs_sb_is_v5(sbp) &&
1142 	    (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR)) {
1143 		rgs->blocks = sbp->sb_rgextents * sbp->sb_rextsize;
1144 		rgs->blklog = mp->m_sb.sb_rgblklog;
1145 		rgs->blkmask = xfs_mask32lo(mp->m_sb.sb_rgblklog);
1146 	} else {
1147 		rgs->blocks = 0;
1148 		rgs->blklog = 0;
1149 		rgs->blkmask = (uint64_t)-1;
1150 	}
1151 }
1152 
1153 /* Update incore sb rt extent size, then recompute the cached rt geometry. */
1154 void
1155 xfs_mount_sb_set_rextsize(
1156 	struct xfs_mount	*mp,
1157 	struct xfs_sb		*sbp,
1158 	xfs_agblock_t		rextsize)
1159 {
1160 	sbp->sb_rextsize = rextsize;
1161 	if (xfs_sb_is_v5(sbp) &&
1162 	    (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR))
1163 		sbp->sb_rgblklog = xfs_compute_rgblklog(sbp->sb_rgextents,
1164 							rextsize);
1165 
1166 	xfs_sb_mount_rextsize(mp, sbp);
1167 }
1168 
1169 /*
1170  * xfs_mount_common
1171  *
1172  * Mount initialization code establishing various mount
1173  * fields from the superblock associated with the given
1174  * mount structure.
1175  *
1176  * Inode geometry are calculated in xfs_ialloc_setup_geometry.
1177  */
1178 void
1179 xfs_sb_mount_common(
1180 	struct xfs_mount	*mp,
1181 	struct xfs_sb		*sbp)
1182 {
1183 	struct xfs_groups	*ags = &mp->m_groups[XG_TYPE_AG];
1184 
1185 	mp->m_agfrotor = 0;
1186 	atomic_set(&mp->m_agirotor, 0);
1187 	mp->m_maxagi = mp->m_sb.sb_agcount;
1188 	mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
1189 	mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
1190 	mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
1191 	mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
1192 	mp->m_blockmask = sbp->sb_blocksize - 1;
1193 	mp->m_blockwsize = xfs_rtbmblock_size(sbp) >> XFS_WORDLOG;
1194 	mp->m_rtx_per_rbmblock = mp->m_blockwsize << XFS_NBWORDLOG;
1195 
1196 	ags->blocks = mp->m_sb.sb_agblocks;
1197 	ags->blklog = mp->m_sb.sb_agblklog;
1198 	ags->blkmask = xfs_mask32lo(mp->m_sb.sb_agblklog);
1199 
1200 	xfs_sb_mount_rextsize(mp, sbp);
1201 
1202 	mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, true);
1203 	mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, false);
1204 	mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
1205 	mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
1206 
1207 	mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, true);
1208 	mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, false);
1209 	mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
1210 	mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
1211 
1212 	mp->m_rmap_mxr[0] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, true);
1213 	mp->m_rmap_mxr[1] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, false);
1214 	mp->m_rmap_mnr[0] = mp->m_rmap_mxr[0] / 2;
1215 	mp->m_rmap_mnr[1] = mp->m_rmap_mxr[1] / 2;
1216 
1217 	mp->m_refc_mxr[0] = xfs_refcountbt_maxrecs(mp, sbp->sb_blocksize, true);
1218 	mp->m_refc_mxr[1] = xfs_refcountbt_maxrecs(mp, sbp->sb_blocksize, false);
1219 	mp->m_refc_mnr[0] = mp->m_refc_mxr[0] / 2;
1220 	mp->m_refc_mnr[1] = mp->m_refc_mxr[1] / 2;
1221 
1222 	mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
1223 	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
1224 	mp->m_ag_max_usable = xfs_alloc_ag_max_usable(mp);
1225 }
1226 
1227 /*
1228  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
1229  * into the superblock buffer to be logged.  It does not provide the higher
1230  * level of locking that is needed to protect the in-core superblock from
1231  * concurrent access.
1232  */
1233 void
1234 xfs_log_sb(
1235 	struct xfs_trans	*tp)
1236 {
1237 	struct xfs_mount	*mp = tp->t_mountp;
1238 	struct xfs_buf		*bp = xfs_trans_getsb(tp);
1239 
1240 	/*
1241 	 * Lazy sb counters don't update the in-core superblock so do that now.
1242 	 * If this is at unmount, the counters will be exactly correct, but at
1243 	 * any other time they will only be ballpark correct because of
1244 	 * reservations that have been taken out percpu counters. If we have an
1245 	 * unclean shutdown, this will be corrected by log recovery rebuilding
1246 	 * the counters from the AGF block counts.
1247 	 */
1248 	if (xfs_has_lazysbcount(mp)) {
1249 		mp->m_sb.sb_icount = percpu_counter_sum_positive(&mp->m_icount);
1250 		mp->m_sb.sb_ifree = min_t(uint64_t,
1251 				percpu_counter_sum_positive(&mp->m_ifree),
1252 				mp->m_sb.sb_icount);
1253 		mp->m_sb.sb_fdblocks =
1254 				percpu_counter_sum_positive(&mp->m_fdblocks);
1255 	}
1256 
1257 	/*
1258 	 * sb_frextents was added to the lazy sb counters when the rt groups
1259 	 * feature was introduced.  This counter can go negative due to the way
1260 	 * we handle nearly-lockless reservations, so we must use the _positive
1261 	 * variant here to avoid writing out nonsense frextents.
1262 	 */
1263 	if (xfs_has_rtgroups(mp))
1264 		mp->m_sb.sb_frextents =
1265 				percpu_counter_sum_positive(&mp->m_frextents);
1266 
1267 	xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
1268 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
1269 	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb) - 1);
1270 }
1271 
1272 /*
1273  * xfs_sync_sb
1274  *
1275  * Sync the superblock to disk.
1276  *
1277  * Note that the caller is responsible for checking the frozen state of the
1278  * filesystem. This procedure uses the non-blocking transaction allocator and
1279  * thus will allow modifications to a frozen fs. This is required because this
1280  * code can be called during the process of freezing where use of the high-level
1281  * allocator would deadlock.
1282  */
1283 int
1284 xfs_sync_sb(
1285 	struct xfs_mount	*mp,
1286 	bool			wait)
1287 {
1288 	struct xfs_trans	*tp;
1289 	int			error;
1290 
1291 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0,
1292 			XFS_TRANS_NO_WRITECOUNT, &tp);
1293 	if (error)
1294 		return error;
1295 
1296 	xfs_log_sb(tp);
1297 	if (wait)
1298 		xfs_trans_set_sync(tp);
1299 	return xfs_trans_commit(tp);
1300 }
1301 
1302 /*
1303  * Update all the secondary superblocks to match the new state of the primary.
1304  * Because we are completely overwriting all the existing fields in the
1305  * secondary superblock buffers, there is no need to read them in from disk.
1306  * Just get a new buffer, stamp it and write it.
1307  *
1308  * The sb buffers need to be cached here so that we serialise against other
1309  * operations that access the secondary superblocks, but we don't want to keep
1310  * them in memory once it is written so we mark it as a one-shot buffer.
1311  */
1312 int
1313 xfs_update_secondary_sbs(
1314 	struct xfs_mount	*mp)
1315 {
1316 	struct xfs_perag	*pag = NULL;
1317 	int			saved_error = 0;
1318 	int			error = 0;
1319 	LIST_HEAD		(buffer_list);
1320 
1321 	/* update secondary superblocks. */
1322 	while ((pag = xfs_perag_next_from(mp, pag, 1))) {
1323 		struct xfs_buf		*bp;
1324 
1325 		error = xfs_buf_get(mp->m_ddev_targp,
1326 				 XFS_AG_DADDR(mp, pag_agno(pag), XFS_SB_DADDR),
1327 				 XFS_FSS_TO_BB(mp, 1), &bp);
1328 		/*
1329 		 * If we get an error reading or writing alternate superblocks,
1330 		 * continue.  xfs_repair chooses the "best" superblock based
1331 		 * on most matches; if we break early, we'll leave more
1332 		 * superblocks un-updated than updated, and xfs_repair may
1333 		 * pick them over the properly-updated primary.
1334 		 */
1335 		if (error) {
1336 			xfs_warn(mp,
1337 		"error allocating secondary superblock for ag %d",
1338 				pag_agno(pag));
1339 			if (!saved_error)
1340 				saved_error = error;
1341 			continue;
1342 		}
1343 
1344 		bp->b_ops = &xfs_sb_buf_ops;
1345 		xfs_buf_oneshot(bp);
1346 		xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
1347 		xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
1348 		xfs_buf_delwri_queue(bp, &buffer_list);
1349 		xfs_buf_relse(bp);
1350 
1351 		/* don't hold too many buffers at once */
1352 		if (pag_agno(pag) % 16)
1353 			continue;
1354 
1355 		error = xfs_buf_delwri_submit(&buffer_list);
1356 		if (error) {
1357 			xfs_warn(mp,
1358 		"write error %d updating a secondary superblock near ag %d",
1359 				error, pag_agno(pag));
1360 			if (!saved_error)
1361 				saved_error = error;
1362 			continue;
1363 		}
1364 	}
1365 	error = xfs_buf_delwri_submit(&buffer_list);
1366 	if (error)
1367 		xfs_warn(mp, "error %d writing secondary superblocks", error);
1368 	return saved_error ? saved_error : error;
1369 }
1370 
1371 /*
1372  * Same behavior as xfs_sync_sb, except that it is always synchronous and it
1373  * also writes the superblock buffer to disk sector 0 immediately.
1374  */
1375 int
1376 xfs_sync_sb_buf(
1377 	struct xfs_mount	*mp,
1378 	bool			update_rtsb)
1379 {
1380 	struct xfs_trans	*tp;
1381 	struct xfs_buf		*bp;
1382 	struct xfs_buf		*rtsb_bp = NULL;
1383 	int			error;
1384 
1385 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0, 0, &tp);
1386 	if (error)
1387 		return error;
1388 
1389 	bp = xfs_trans_getsb(tp);
1390 	xfs_log_sb(tp);
1391 	xfs_trans_bhold(tp, bp);
1392 	if (update_rtsb) {
1393 		rtsb_bp = xfs_log_rtsb(tp, bp);
1394 		if (rtsb_bp)
1395 			xfs_trans_bhold(tp, rtsb_bp);
1396 	}
1397 	xfs_trans_set_sync(tp);
1398 	error = xfs_trans_commit(tp);
1399 	if (error)
1400 		goto out;
1401 	/*
1402 	 * write out the sb buffer to get the changes to disk
1403 	 */
1404 	error = xfs_bwrite(bp);
1405 	if (!error && rtsb_bp)
1406 		error = xfs_bwrite(rtsb_bp);
1407 out:
1408 	if (rtsb_bp)
1409 		xfs_buf_relse(rtsb_bp);
1410 	xfs_buf_relse(bp);
1411 	return error;
1412 }
1413 
1414 void
1415 xfs_fs_geometry(
1416 	struct xfs_mount	*mp,
1417 	struct xfs_fsop_geom	*geo,
1418 	int			struct_version)
1419 {
1420 	struct xfs_sb		*sbp = &mp->m_sb;
1421 
1422 	memset(geo, 0, sizeof(struct xfs_fsop_geom));
1423 
1424 	geo->blocksize = sbp->sb_blocksize;
1425 	geo->rtextsize = sbp->sb_rextsize;
1426 	geo->agblocks = sbp->sb_agblocks;
1427 	geo->agcount = sbp->sb_agcount;
1428 	geo->logblocks = sbp->sb_logblocks;
1429 	geo->sectsize = sbp->sb_sectsize;
1430 	geo->inodesize = sbp->sb_inodesize;
1431 	geo->imaxpct = sbp->sb_imax_pct;
1432 	geo->datablocks = sbp->sb_dblocks;
1433 	geo->rtblocks = sbp->sb_rblocks;
1434 	geo->rtextents = sbp->sb_rextents;
1435 	geo->logstart = sbp->sb_logstart;
1436 	BUILD_BUG_ON(sizeof(geo->uuid) != sizeof(sbp->sb_uuid));
1437 	memcpy(geo->uuid, &sbp->sb_uuid, sizeof(sbp->sb_uuid));
1438 
1439 	if (struct_version < 2)
1440 		return;
1441 
1442 	geo->sunit = sbp->sb_unit;
1443 	geo->swidth = sbp->sb_width;
1444 
1445 	if (struct_version < 3)
1446 		return;
1447 
1448 	geo->version = XFS_FSOP_GEOM_VERSION;
1449 	geo->flags = XFS_FSOP_GEOM_FLAGS_NLINK |
1450 		     XFS_FSOP_GEOM_FLAGS_DIRV2 |
1451 		     XFS_FSOP_GEOM_FLAGS_EXTFLG;
1452 	if (xfs_has_attr(mp))
1453 		geo->flags |= XFS_FSOP_GEOM_FLAGS_ATTR;
1454 	if (xfs_has_quota(mp))
1455 		geo->flags |= XFS_FSOP_GEOM_FLAGS_QUOTA;
1456 	if (xfs_has_align(mp))
1457 		geo->flags |= XFS_FSOP_GEOM_FLAGS_IALIGN;
1458 	if (xfs_has_dalign(mp))
1459 		geo->flags |= XFS_FSOP_GEOM_FLAGS_DALIGN;
1460 	if (xfs_has_asciici(mp))
1461 		geo->flags |= XFS_FSOP_GEOM_FLAGS_DIRV2CI;
1462 	if (xfs_has_lazysbcount(mp))
1463 		geo->flags |= XFS_FSOP_GEOM_FLAGS_LAZYSB;
1464 	if (xfs_has_attr2(mp))
1465 		geo->flags |= XFS_FSOP_GEOM_FLAGS_ATTR2;
1466 	if (xfs_has_projid32(mp))
1467 		geo->flags |= XFS_FSOP_GEOM_FLAGS_PROJID32;
1468 	if (xfs_has_crc(mp))
1469 		geo->flags |= XFS_FSOP_GEOM_FLAGS_V5SB;
1470 	if (xfs_has_ftype(mp))
1471 		geo->flags |= XFS_FSOP_GEOM_FLAGS_FTYPE;
1472 	if (xfs_has_finobt(mp))
1473 		geo->flags |= XFS_FSOP_GEOM_FLAGS_FINOBT;
1474 	if (xfs_has_sparseinodes(mp))
1475 		geo->flags |= XFS_FSOP_GEOM_FLAGS_SPINODES;
1476 	if (xfs_has_rmapbt(mp))
1477 		geo->flags |= XFS_FSOP_GEOM_FLAGS_RMAPBT;
1478 	if (xfs_has_reflink(mp))
1479 		geo->flags |= XFS_FSOP_GEOM_FLAGS_REFLINK;
1480 	if (xfs_has_bigtime(mp))
1481 		geo->flags |= XFS_FSOP_GEOM_FLAGS_BIGTIME;
1482 	if (xfs_has_inobtcounts(mp))
1483 		geo->flags |= XFS_FSOP_GEOM_FLAGS_INOBTCNT;
1484 	if (xfs_has_parent(mp))
1485 		geo->flags |= XFS_FSOP_GEOM_FLAGS_PARENT;
1486 	if (xfs_has_sector(mp)) {
1487 		geo->flags |= XFS_FSOP_GEOM_FLAGS_SECTOR;
1488 		geo->logsectsize = sbp->sb_logsectsize;
1489 	} else {
1490 		geo->logsectsize = BBSIZE;
1491 	}
1492 	if (xfs_has_large_extent_counts(mp))
1493 		geo->flags |= XFS_FSOP_GEOM_FLAGS_NREXT64;
1494 	if (xfs_has_exchange_range(mp))
1495 		geo->flags |= XFS_FSOP_GEOM_FLAGS_EXCHANGE_RANGE;
1496 	if (xfs_has_metadir(mp))
1497 		geo->flags |= XFS_FSOP_GEOM_FLAGS_METADIR;
1498 	geo->rtsectsize = sbp->sb_blocksize;
1499 	geo->dirblocksize = xfs_dir2_dirblock_bytes(sbp);
1500 
1501 	if (struct_version < 4)
1502 		return;
1503 
1504 	if (xfs_has_logv2(mp))
1505 		geo->flags |= XFS_FSOP_GEOM_FLAGS_LOGV2;
1506 
1507 	geo->logsunit = sbp->sb_logsunit;
1508 
1509 	if (struct_version < 5)
1510 		return;
1511 
1512 	geo->version = XFS_FSOP_GEOM_VERSION_V5;
1513 
1514 	if (xfs_has_rtgroups(mp)) {
1515 		geo->rgcount = sbp->sb_rgcount;
1516 		geo->rgextents = sbp->sb_rgextents;
1517 	}
1518 }
1519 
1520 /* Read a secondary superblock. */
1521 int
1522 xfs_sb_read_secondary(
1523 	struct xfs_mount	*mp,
1524 	struct xfs_trans	*tp,
1525 	xfs_agnumber_t		agno,
1526 	struct xfs_buf		**bpp)
1527 {
1528 	struct xfs_buf		*bp;
1529 	int			error;
1530 
1531 	ASSERT(agno != 0 && agno != NULLAGNUMBER);
1532 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
1533 			XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
1534 			XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops);
1535 	if (xfs_metadata_is_sick(error))
1536 		xfs_agno_mark_sick(mp, agno, XFS_SICK_AG_SB);
1537 	if (error)
1538 		return error;
1539 	xfs_buf_set_ref(bp, XFS_SSB_REF);
1540 	*bpp = bp;
1541 	return 0;
1542 }
1543 
1544 /* Get an uninitialised secondary superblock buffer. */
1545 int
1546 xfs_sb_get_secondary(
1547 	struct xfs_mount	*mp,
1548 	struct xfs_trans	*tp,
1549 	xfs_agnumber_t		agno,
1550 	struct xfs_buf		**bpp)
1551 {
1552 	struct xfs_buf		*bp;
1553 	int			error;
1554 
1555 	ASSERT(agno != 0 && agno != NULLAGNUMBER);
1556 	error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
1557 			XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
1558 			XFS_FSS_TO_BB(mp, 1), 0, &bp);
1559 	if (error)
1560 		return error;
1561 	bp->b_ops = &xfs_sb_buf_ops;
1562 	xfs_buf_oneshot(bp);
1563 	*bpp = bp;
1564 	return 0;
1565 }
1566 
1567 /*
1568  * sunit, swidth, sectorsize(optional with 0) should be all in bytes, so users
1569  * won't be confused by values in error messages.  This function returns false
1570  * if the stripe geometry is invalid and the caller is unable to repair the
1571  * stripe configuration later in the mount process.
1572  */
1573 bool
1574 xfs_validate_stripe_geometry(
1575 	struct xfs_mount	*mp,
1576 	__s64			sunit,
1577 	__s64			swidth,
1578 	int			sectorsize,
1579 	bool			may_repair,
1580 	bool			silent)
1581 {
1582 	if (swidth > INT_MAX) {
1583 		if (!silent)
1584 			xfs_notice(mp,
1585 "stripe width (%lld) is too large", swidth);
1586 		goto check_override;
1587 	}
1588 
1589 	if (sunit > swidth) {
1590 		if (!silent)
1591 			xfs_notice(mp,
1592 "stripe unit (%lld) is larger than the stripe width (%lld)", sunit, swidth);
1593 		goto check_override;
1594 	}
1595 
1596 	if (sectorsize && (int)sunit % sectorsize) {
1597 		if (!silent)
1598 			xfs_notice(mp,
1599 "stripe unit (%lld) must be a multiple of the sector size (%d)",
1600 				   sunit, sectorsize);
1601 		goto check_override;
1602 	}
1603 
1604 	if (sunit && !swidth) {
1605 		if (!silent)
1606 			xfs_notice(mp,
1607 "invalid stripe unit (%lld) and stripe width of 0", sunit);
1608 		goto check_override;
1609 	}
1610 
1611 	if (!sunit && swidth) {
1612 		if (!silent)
1613 			xfs_notice(mp,
1614 "invalid stripe width (%lld) and stripe unit of 0", swidth);
1615 		goto check_override;
1616 	}
1617 
1618 	if (sunit && (int)swidth % (int)sunit) {
1619 		if (!silent)
1620 			xfs_notice(mp,
1621 "stripe width (%lld) must be a multiple of the stripe unit (%lld)",
1622 				   swidth, sunit);
1623 		goto check_override;
1624 	}
1625 	return true;
1626 
1627 check_override:
1628 	if (!may_repair)
1629 		return false;
1630 	/*
1631 	 * During mount, mp->m_dalign will not be set unless the sunit mount
1632 	 * option was set. If it was set, ignore the bad stripe alignment values
1633 	 * and allow the validation and overwrite later in the mount process to
1634 	 * attempt to overwrite the bad stripe alignment values with the values
1635 	 * supplied by mount options.
1636 	 */
1637 	if (!mp->m_dalign)
1638 		return false;
1639 	if (!silent)
1640 		xfs_notice(mp,
1641 "Will try to correct with specified mount options sunit (%d) and swidth (%d)",
1642 			BBTOB(mp->m_dalign), BBTOB(mp->m_swidth));
1643 	return true;
1644 }
1645 
1646 /*
1647  * Compute the maximum level number of the realtime summary file, as defined by
1648  * mkfs.  The historic use of highbit32 on a 64-bit quantity prohibited correct
1649  * use of rt volumes with more than 2^32 extents.
1650  */
1651 uint8_t
1652 xfs_compute_rextslog(
1653 	xfs_rtbxlen_t		rtextents)
1654 {
1655 	if (!rtextents)
1656 		return 0;
1657 	return xfs_highbit64(rtextents);
1658 }
1659