xref: /linux/fs/xfs/libxfs/xfs_sb.c (revision 5e2cb28dd7e182dfa641550dfa225913509ad45d)
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 
29 /*
30  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
31  */
32 
33 /*
34  * Check that all the V4 feature bits that the V5 filesystem format requires are
35  * correctly set.
36  */
37 static bool
38 xfs_sb_validate_v5_features(
39 	struct xfs_sb	*sbp)
40 {
41 	/* We must not have any unknown V4 feature bits set */
42 	if (sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS)
43 		return false;
44 
45 	/*
46 	 * The CRC bit is considered an invalid V4 flag, so we have to add it
47 	 * manually to the OKBITS mask.
48 	 */
49 	if (sbp->sb_features2 & ~(XFS_SB_VERSION2_OKBITS |
50 				  XFS_SB_VERSION2_CRCBIT))
51 		return false;
52 
53 	/* Now check all the required V4 feature flags are set. */
54 
55 #define V5_VERS_FLAGS	(XFS_SB_VERSION_NLINKBIT	| \
56 			XFS_SB_VERSION_ALIGNBIT		| \
57 			XFS_SB_VERSION_LOGV2BIT		| \
58 			XFS_SB_VERSION_EXTFLGBIT	| \
59 			XFS_SB_VERSION_DIRV2BIT		| \
60 			XFS_SB_VERSION_MOREBITSBIT)
61 
62 #define V5_FEAT_FLAGS	(XFS_SB_VERSION2_LAZYSBCOUNTBIT	| \
63 			XFS_SB_VERSION2_ATTR2BIT	| \
64 			XFS_SB_VERSION2_PROJID32BIT	| \
65 			XFS_SB_VERSION2_CRCBIT)
66 
67 	if ((sbp->sb_versionnum & V5_VERS_FLAGS) != V5_VERS_FLAGS)
68 		return false;
69 	if ((sbp->sb_features2 & V5_FEAT_FLAGS) != V5_FEAT_FLAGS)
70 		return false;
71 	return true;
72 }
73 
74 /*
75  * We current support XFS v5 formats with known features and v4 superblocks with
76  * at least V2 directories.
77  */
78 bool
79 xfs_sb_good_version(
80 	struct xfs_sb	*sbp)
81 {
82 	/*
83 	 * All v5 filesystems are supported, but we must check that all the
84 	 * required v4 feature flags are enabled correctly as the code checks
85 	 * those flags and not for v5 support.
86 	 */
87 	if (xfs_sb_is_v5(sbp))
88 		return xfs_sb_validate_v5_features(sbp);
89 
90 	/* versions prior to v4 are not supported */
91 	if (XFS_SB_VERSION_NUM(sbp) != XFS_SB_VERSION_4)
92 		return false;
93 
94 	/* We must not have any unknown v4 feature bits set */
95 	if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
96 	    ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
97 	     (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS)))
98 		return false;
99 
100 	/* V4 filesystems need v2 directories and unwritten extents */
101 	if (!(sbp->sb_versionnum & XFS_SB_VERSION_DIRV2BIT))
102 		return false;
103 	if (!(sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT))
104 		return false;
105 
106 	/* It's a supported v4 filesystem */
107 	return true;
108 }
109 
110 uint64_t
111 xfs_sb_version_to_features(
112 	struct xfs_sb	*sbp)
113 {
114 	uint64_t	features = 0;
115 
116 	/* optional V4 features */
117 	if (sbp->sb_rblocks > 0)
118 		features |= XFS_FEAT_REALTIME;
119 	if (sbp->sb_versionnum & XFS_SB_VERSION_NLINKBIT)
120 		features |= XFS_FEAT_NLINK;
121 	if (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT)
122 		features |= XFS_FEAT_ATTR;
123 	if (sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT)
124 		features |= XFS_FEAT_QUOTA;
125 	if (sbp->sb_versionnum & XFS_SB_VERSION_ALIGNBIT)
126 		features |= XFS_FEAT_ALIGN;
127 	if (sbp->sb_versionnum & XFS_SB_VERSION_LOGV2BIT)
128 		features |= XFS_FEAT_LOGV2;
129 	if (sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT)
130 		features |= XFS_FEAT_DALIGN;
131 	if (sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT)
132 		features |= XFS_FEAT_EXTFLG;
133 	if (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT)
134 		features |= XFS_FEAT_SECTOR;
135 	if (sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT)
136 		features |= XFS_FEAT_ASCIICI;
137 	if (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) {
138 		if (sbp->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT)
139 			features |= XFS_FEAT_LAZYSBCOUNT;
140 		if (sbp->sb_features2 & XFS_SB_VERSION2_ATTR2BIT)
141 			features |= XFS_FEAT_ATTR2;
142 		if (sbp->sb_features2 & XFS_SB_VERSION2_PROJID32BIT)
143 			features |= XFS_FEAT_PROJID32;
144 		if (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE)
145 			features |= XFS_FEAT_FTYPE;
146 	}
147 
148 	if (!xfs_sb_is_v5(sbp))
149 		return features;
150 
151 	/* Always on V5 features */
152 	features |= XFS_FEAT_ALIGN | XFS_FEAT_LOGV2 | XFS_FEAT_EXTFLG |
153 		    XFS_FEAT_LAZYSBCOUNT | XFS_FEAT_ATTR2 | XFS_FEAT_PROJID32 |
154 		    XFS_FEAT_V3INODES | XFS_FEAT_CRC | XFS_FEAT_PQUOTINO;
155 
156 	/* Optional V5 features */
157 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT)
158 		features |= XFS_FEAT_FINOBT;
159 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT)
160 		features |= XFS_FEAT_RMAPBT;
161 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_REFLINK)
162 		features |= XFS_FEAT_REFLINK;
163 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_INOBTCNT)
164 		features |= XFS_FEAT_INOBTCNT;
165 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_FTYPE)
166 		features |= XFS_FEAT_FTYPE;
167 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES)
168 		features |= XFS_FEAT_SPINODES;
169 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
170 		features |= XFS_FEAT_META_UUID;
171 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_BIGTIME)
172 		features |= XFS_FEAT_BIGTIME;
173 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
174 		features |= XFS_FEAT_NEEDSREPAIR;
175 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
176 		features |= XFS_FEAT_NREXT64;
177 
178 	return features;
179 }
180 
181 /* Check all the superblock fields we care about when reading one in. */
182 STATIC int
183 xfs_validate_sb_read(
184 	struct xfs_mount	*mp,
185 	struct xfs_sb		*sbp)
186 {
187 	if (!xfs_sb_is_v5(sbp))
188 		return 0;
189 
190 	/*
191 	 * Version 5 superblock feature mask validation. Reject combinations
192 	 * the kernel cannot support up front before checking anything else.
193 	 */
194 	if (xfs_sb_has_compat_feature(sbp, XFS_SB_FEAT_COMPAT_UNKNOWN)) {
195 		xfs_warn(mp,
196 "Superblock has unknown compatible features (0x%x) enabled.",
197 			(sbp->sb_features_compat & XFS_SB_FEAT_COMPAT_UNKNOWN));
198 		xfs_warn(mp,
199 "Using a more recent kernel is recommended.");
200 	}
201 
202 	if (xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
203 		xfs_alert(mp,
204 "Superblock has unknown read-only compatible features (0x%x) enabled.",
205 			(sbp->sb_features_ro_compat &
206 					XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
207 		if (!xfs_is_readonly(mp)) {
208 			xfs_warn(mp,
209 "Attempted to mount read-only compatible filesystem read-write.");
210 			xfs_warn(mp,
211 "Filesystem can only be safely mounted read only.");
212 
213 			return -EINVAL;
214 		}
215 	}
216 	if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
217 		xfs_warn(mp,
218 "Superblock has unknown incompatible features (0x%x) enabled.",
219 			(sbp->sb_features_incompat &
220 					XFS_SB_FEAT_INCOMPAT_UNKNOWN));
221 		xfs_warn(mp,
222 "Filesystem cannot be safely mounted by this kernel.");
223 		return -EINVAL;
224 	}
225 
226 	return 0;
227 }
228 
229 /* Check all the superblock fields we care about when writing one out. */
230 STATIC int
231 xfs_validate_sb_write(
232 	struct xfs_mount	*mp,
233 	struct xfs_buf		*bp,
234 	struct xfs_sb		*sbp)
235 {
236 	/*
237 	 * Carry out additional sb summary counter sanity checks when we write
238 	 * the superblock.  We skip this in the read validator because there
239 	 * could be newer superblocks in the log and if the values are garbage
240 	 * even after replay we'll recalculate them at the end of log mount.
241 	 *
242 	 * mkfs has traditionally written zeroed counters to inprogress and
243 	 * secondary superblocks, so allow this usage to continue because
244 	 * we never read counters from such superblocks.
245 	 */
246 	if (xfs_buf_daddr(bp) == XFS_SB_DADDR && !sbp->sb_inprogress &&
247 	    (sbp->sb_fdblocks > sbp->sb_dblocks ||
248 	     !xfs_verify_icount(mp, sbp->sb_icount) ||
249 	     sbp->sb_ifree > sbp->sb_icount)) {
250 		xfs_warn(mp, "SB summary counter sanity check failed");
251 		return -EFSCORRUPTED;
252 	}
253 
254 	if (!xfs_sb_is_v5(sbp))
255 		return 0;
256 
257 	/*
258 	 * Version 5 superblock feature mask validation. Reject combinations
259 	 * the kernel cannot support since we checked for unsupported bits in
260 	 * the read verifier, which means that memory is corrupt.
261 	 */
262 	if (xfs_sb_has_compat_feature(sbp, XFS_SB_FEAT_COMPAT_UNKNOWN)) {
263 		xfs_warn(mp,
264 "Corruption detected in superblock compatible features (0x%x)!",
265 			(sbp->sb_features_compat & XFS_SB_FEAT_COMPAT_UNKNOWN));
266 		return -EFSCORRUPTED;
267 	}
268 
269 	if (!xfs_is_readonly(mp) &&
270 	    xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
271 		xfs_alert(mp,
272 "Corruption detected in superblock read-only compatible features (0x%x)!",
273 			(sbp->sb_features_ro_compat &
274 					XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
275 		return -EFSCORRUPTED;
276 	}
277 	if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
278 		xfs_warn(mp,
279 "Corruption detected in superblock incompatible features (0x%x)!",
280 			(sbp->sb_features_incompat &
281 					XFS_SB_FEAT_INCOMPAT_UNKNOWN));
282 		return -EFSCORRUPTED;
283 	}
284 	if (xfs_sb_has_incompat_log_feature(sbp,
285 			XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) {
286 		xfs_warn(mp,
287 "Corruption detected in superblock incompatible log features (0x%x)!",
288 			(sbp->sb_features_log_incompat &
289 					XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));
290 		return -EFSCORRUPTED;
291 	}
292 
293 	/*
294 	 * We can't read verify the sb LSN because the read verifier is called
295 	 * before the log is allocated and processed. We know the log is set up
296 	 * before write verifier calls, so check it here.
297 	 */
298 	if (!xfs_log_check_lsn(mp, sbp->sb_lsn))
299 		return -EFSCORRUPTED;
300 
301 	return 0;
302 }
303 
304 /* Check the validity of the SB. */
305 STATIC int
306 xfs_validate_sb_common(
307 	struct xfs_mount	*mp,
308 	struct xfs_buf		*bp,
309 	struct xfs_sb		*sbp)
310 {
311 	struct xfs_dsb		*dsb = bp->b_addr;
312 	uint32_t		agcount = 0;
313 	uint32_t		rem;
314 	bool			has_dalign;
315 
316 	if (!xfs_verify_magic(bp, dsb->sb_magicnum)) {
317 		xfs_warn(mp,
318 "Superblock has bad magic number 0x%x. Not an XFS filesystem?",
319 			be32_to_cpu(dsb->sb_magicnum));
320 		return -EWRONGFS;
321 	}
322 
323 	if (!xfs_sb_good_version(sbp)) {
324 		xfs_warn(mp,
325 "Superblock has unknown features enabled or corrupted feature masks.");
326 		return -EWRONGFS;
327 	}
328 
329 	/*
330 	 * Validate feature flags and state
331 	 */
332 	if (xfs_sb_is_v5(sbp)) {
333 		if (sbp->sb_blocksize < XFS_MIN_CRC_BLOCKSIZE) {
334 			xfs_notice(mp,
335 "Block size (%u bytes) too small for Version 5 superblock (minimum %d bytes)",
336 				sbp->sb_blocksize, XFS_MIN_CRC_BLOCKSIZE);
337 			return -EFSCORRUPTED;
338 		}
339 
340 		/* V5 has a separate project quota inode */
341 		if (sbp->sb_qflags & (XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD)) {
342 			xfs_notice(mp,
343 			   "Version 5 of Super block has XFS_OQUOTA bits.");
344 			return -EFSCORRUPTED;
345 		}
346 
347 		/*
348 		 * Full inode chunks must be aligned to inode chunk size when
349 		 * sparse inodes are enabled to support the sparse chunk
350 		 * allocation algorithm and prevent overlapping inode records.
351 		 */
352 		if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES) {
353 			uint32_t	align;
354 
355 			align = XFS_INODES_PER_CHUNK * sbp->sb_inodesize
356 					>> sbp->sb_blocklog;
357 			if (sbp->sb_inoalignmt != align) {
358 				xfs_warn(mp,
359 "Inode block alignment (%u) must match chunk size (%u) for sparse inodes.",
360 					 sbp->sb_inoalignmt, align);
361 				return -EINVAL;
362 			}
363 		}
364 	} else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
365 				XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
366 			xfs_notice(mp,
367 "Superblock earlier than Version 5 has XFS_{P|G}QUOTA_{ENFD|CHKD} bits.");
368 			return -EFSCORRUPTED;
369 	}
370 
371 	if (unlikely(
372 	    sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
373 		xfs_warn(mp,
374 		"filesystem is marked as having an external log; "
375 		"specify logdev on the mount command line.");
376 		return -EINVAL;
377 	}
378 
379 	if (unlikely(
380 	    sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
381 		xfs_warn(mp,
382 		"filesystem is marked as having an internal log; "
383 		"do not specify logdev on the mount command line.");
384 		return -EINVAL;
385 	}
386 
387 	/* Compute agcount for this number of dblocks and agblocks */
388 	if (sbp->sb_agblocks) {
389 		agcount = div_u64_rem(sbp->sb_dblocks, sbp->sb_agblocks, &rem);
390 		if (rem)
391 			agcount++;
392 	}
393 
394 	/*
395 	 * More sanity checking.  Most of these were stolen directly from
396 	 * xfs_repair.
397 	 */
398 	if (unlikely(
399 	    sbp->sb_agcount <= 0					||
400 	    sbp->sb_sectsize < XFS_MIN_SECTORSIZE			||
401 	    sbp->sb_sectsize > XFS_MAX_SECTORSIZE			||
402 	    sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG			||
403 	    sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG			||
404 	    sbp->sb_sectsize != (1 << sbp->sb_sectlog)			||
405 	    sbp->sb_blocksize < XFS_MIN_BLOCKSIZE			||
406 	    sbp->sb_blocksize > XFS_MAX_BLOCKSIZE			||
407 	    sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG			||
408 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
409 	    sbp->sb_blocksize != (1 << sbp->sb_blocklog)		||
410 	    sbp->sb_dirblklog + sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
411 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
412 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
413 	    sbp->sb_inodelog < XFS_DINODE_MIN_LOG			||
414 	    sbp->sb_inodelog > XFS_DINODE_MAX_LOG			||
415 	    sbp->sb_inodesize != (1 << sbp->sb_inodelog)		||
416 	    sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
417 	    XFS_FSB_TO_B(mp, sbp->sb_agblocks) < XFS_MIN_AG_BYTES	||
418 	    XFS_FSB_TO_B(mp, sbp->sb_agblocks) > XFS_MAX_AG_BYTES	||
419 	    sbp->sb_agblklog != xfs_highbit32(sbp->sb_agblocks - 1) + 1	||
420 	    agcount == 0 || agcount != sbp->sb_agcount			||
421 	    (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)	||
422 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
423 	    (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)	||
424 	    (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)	||
425 	    sbp->sb_dblocks == 0					||
426 	    sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)			||
427 	    sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)			||
428 	    sbp->sb_shared_vn != 0)) {
429 		xfs_notice(mp, "SB sanity check failed");
430 		return -EFSCORRUPTED;
431 	}
432 
433 	/*
434 	 * Logs that are too large are not supported at all. Reject them
435 	 * outright. Logs that are too small are tolerated on v4 filesystems,
436 	 * but we can only check that when mounting the log. Hence we skip
437 	 * those checks here.
438 	 */
439 	if (sbp->sb_logblocks > XFS_MAX_LOG_BLOCKS) {
440 		xfs_notice(mp,
441 		"Log size 0x%x blocks too large, maximum size is 0x%llx blocks",
442 			 sbp->sb_logblocks, XFS_MAX_LOG_BLOCKS);
443 		return -EFSCORRUPTED;
444 	}
445 
446 	if (XFS_FSB_TO_B(mp, sbp->sb_logblocks) > XFS_MAX_LOG_BYTES) {
447 		xfs_warn(mp,
448 		"log size 0x%llx bytes too large, maximum size is 0x%llx bytes",
449 			 XFS_FSB_TO_B(mp, sbp->sb_logblocks),
450 			 XFS_MAX_LOG_BYTES);
451 		return -EFSCORRUPTED;
452 	}
453 
454 	/*
455 	 * Do not allow filesystems with corrupted log sector or stripe units to
456 	 * be mounted. We cannot safely size the iclogs or write to the log if
457 	 * the log stripe unit is not valid.
458 	 */
459 	if (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT) {
460 		if (sbp->sb_logsectsize != (1U << sbp->sb_logsectlog)) {
461 			xfs_notice(mp,
462 			"log sector size in bytes/log2 (0x%x/0x%x) must match",
463 				sbp->sb_logsectsize, 1U << sbp->sb_logsectlog);
464 			return -EFSCORRUPTED;
465 		}
466 	} else if (sbp->sb_logsectsize || sbp->sb_logsectlog) {
467 		xfs_notice(mp,
468 		"log sector size in bytes/log2 (0x%x/0x%x) are not zero",
469 			sbp->sb_logsectsize, sbp->sb_logsectlog);
470 		return -EFSCORRUPTED;
471 	}
472 
473 	if (sbp->sb_logsunit > 1) {
474 		if (sbp->sb_logsunit % sbp->sb_blocksize) {
475 			xfs_notice(mp,
476 		"log stripe unit 0x%x bytes must be a multiple of block size",
477 				sbp->sb_logsunit);
478 			return -EFSCORRUPTED;
479 		}
480 		if (sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE) {
481 			xfs_notice(mp,
482 		"log stripe unit 0x%x bytes over maximum size (0x%x bytes)",
483 				sbp->sb_logsunit, XLOG_MAX_RECORD_BSIZE);
484 			return -EFSCORRUPTED;
485 		}
486 	}
487 
488 	/* Validate the realtime geometry; stolen from xfs_repair */
489 	if (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE ||
490 	    sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) {
491 		xfs_notice(mp,
492 			"realtime extent sanity check failed");
493 		return -EFSCORRUPTED;
494 	}
495 
496 	if (sbp->sb_rblocks == 0) {
497 		if (sbp->sb_rextents != 0 || sbp->sb_rbmblocks != 0 ||
498 		    sbp->sb_rextslog != 0 || sbp->sb_frextents != 0) {
499 			xfs_notice(mp,
500 				"realtime zeroed geometry check failed");
501 			return -EFSCORRUPTED;
502 		}
503 	} else {
504 		uint64_t	rexts;
505 		uint64_t	rbmblocks;
506 
507 		rexts = div_u64(sbp->sb_rblocks, sbp->sb_rextsize);
508 		rbmblocks = howmany_64(sbp->sb_rextents,
509 				       NBBY * sbp->sb_blocksize);
510 
511 		if (sbp->sb_rextents != rexts ||
512 		    sbp->sb_rextslog != xfs_highbit32(sbp->sb_rextents) ||
513 		    sbp->sb_rbmblocks != rbmblocks) {
514 			xfs_notice(mp,
515 				"realtime geometry sanity check failed");
516 			return -EFSCORRUPTED;
517 		}
518 	}
519 
520 	/*
521 	 * Either (sb_unit and !hasdalign) or (!sb_unit and hasdalign)
522 	 * would imply the image is corrupted.
523 	 */
524 	has_dalign = sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT;
525 	if (!!sbp->sb_unit ^ has_dalign) {
526 		xfs_notice(mp, "SB stripe alignment sanity check failed");
527 		return -EFSCORRUPTED;
528 	}
529 
530 	if (!xfs_validate_stripe_geometry(mp, XFS_FSB_TO_B(mp, sbp->sb_unit),
531 			XFS_FSB_TO_B(mp, sbp->sb_width), 0, false))
532 		return -EFSCORRUPTED;
533 
534 	/*
535 	 * Currently only very few inode sizes are supported.
536 	 */
537 	switch (sbp->sb_inodesize) {
538 	case 256:
539 	case 512:
540 	case 1024:
541 	case 2048:
542 		break;
543 	default:
544 		xfs_warn(mp, "inode size of %d bytes not supported",
545 				sbp->sb_inodesize);
546 		return -ENOSYS;
547 	}
548 
549 	return 0;
550 }
551 
552 void
553 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
554 {
555 	/*
556 	 * older mkfs doesn't initialize quota inodes to NULLFSINO. This
557 	 * leads to in-core values having two different values for a quota
558 	 * inode to be invalid: 0 and NULLFSINO. Change it to a single value
559 	 * NULLFSINO.
560 	 *
561 	 * Note that this change affect only the in-core values. These
562 	 * values are not written back to disk unless any quota information
563 	 * is written to the disk. Even in that case, sb_pquotino field is
564 	 * not written to disk unless the superblock supports pquotino.
565 	 */
566 	if (sbp->sb_uquotino == 0)
567 		sbp->sb_uquotino = NULLFSINO;
568 	if (sbp->sb_gquotino == 0)
569 		sbp->sb_gquotino = NULLFSINO;
570 	if (sbp->sb_pquotino == 0)
571 		sbp->sb_pquotino = NULLFSINO;
572 
573 	/*
574 	 * We need to do these manipilations only if we are working
575 	 * with an older version of on-disk superblock.
576 	 */
577 	if (xfs_sb_is_v5(sbp))
578 		return;
579 
580 	if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
581 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
582 					XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
583 	if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
584 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
585 					XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
586 	sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
587 
588 	if (sbp->sb_qflags & XFS_PQUOTA_ACCT &&
589 	    sbp->sb_gquotino != NULLFSINO)  {
590 		/*
591 		 * In older version of superblock, on-disk superblock only
592 		 * has sb_gquotino, and in-core superblock has both sb_gquotino
593 		 * and sb_pquotino. But, only one of them is supported at any
594 		 * point of time. So, if PQUOTA is set in disk superblock,
595 		 * copy over sb_gquotino to sb_pquotino.  The NULLFSINO test
596 		 * above is to make sure we don't do this twice and wipe them
597 		 * both out!
598 		 */
599 		sbp->sb_pquotino = sbp->sb_gquotino;
600 		sbp->sb_gquotino = NULLFSINO;
601 	}
602 }
603 
604 static void
605 __xfs_sb_from_disk(
606 	struct xfs_sb	*to,
607 	struct xfs_dsb	*from,
608 	bool		convert_xquota)
609 {
610 	to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
611 	to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
612 	to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
613 	to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
614 	to->sb_rextents = be64_to_cpu(from->sb_rextents);
615 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
616 	to->sb_logstart = be64_to_cpu(from->sb_logstart);
617 	to->sb_rootino = be64_to_cpu(from->sb_rootino);
618 	to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
619 	to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
620 	to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
621 	to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
622 	to->sb_agcount = be32_to_cpu(from->sb_agcount);
623 	to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
624 	to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
625 	to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
626 	to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
627 	to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
628 	to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
629 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
630 	to->sb_blocklog = from->sb_blocklog;
631 	to->sb_sectlog = from->sb_sectlog;
632 	to->sb_inodelog = from->sb_inodelog;
633 	to->sb_inopblog = from->sb_inopblog;
634 	to->sb_agblklog = from->sb_agblklog;
635 	to->sb_rextslog = from->sb_rextslog;
636 	to->sb_inprogress = from->sb_inprogress;
637 	to->sb_imax_pct = from->sb_imax_pct;
638 	to->sb_icount = be64_to_cpu(from->sb_icount);
639 	to->sb_ifree = be64_to_cpu(from->sb_ifree);
640 	to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
641 	to->sb_frextents = be64_to_cpu(from->sb_frextents);
642 	to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
643 	to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
644 	to->sb_qflags = be16_to_cpu(from->sb_qflags);
645 	to->sb_flags = from->sb_flags;
646 	to->sb_shared_vn = from->sb_shared_vn;
647 	to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
648 	to->sb_unit = be32_to_cpu(from->sb_unit);
649 	to->sb_width = be32_to_cpu(from->sb_width);
650 	to->sb_dirblklog = from->sb_dirblklog;
651 	to->sb_logsectlog = from->sb_logsectlog;
652 	to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
653 	to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
654 	to->sb_features2 = be32_to_cpu(from->sb_features2);
655 	to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
656 	to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
657 	to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
658 	to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
659 	to->sb_features_log_incompat =
660 				be32_to_cpu(from->sb_features_log_incompat);
661 	/* crc is only used on disk, not in memory; just init to 0 here. */
662 	to->sb_crc = 0;
663 	to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
664 	to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
665 	to->sb_lsn = be64_to_cpu(from->sb_lsn);
666 	/*
667 	 * sb_meta_uuid is only on disk if it differs from sb_uuid and the
668 	 * feature flag is set; if not set we keep it only in memory.
669 	 */
670 	if (xfs_sb_is_v5(to) &&
671 	    (to->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID))
672 		uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
673 	else
674 		uuid_copy(&to->sb_meta_uuid, &from->sb_uuid);
675 	/* Convert on-disk flags to in-memory flags? */
676 	if (convert_xquota)
677 		xfs_sb_quota_from_disk(to);
678 }
679 
680 void
681 xfs_sb_from_disk(
682 	struct xfs_sb	*to,
683 	struct xfs_dsb	*from)
684 {
685 	__xfs_sb_from_disk(to, from, true);
686 }
687 
688 static void
689 xfs_sb_quota_to_disk(
690 	struct xfs_dsb	*to,
691 	struct xfs_sb	*from)
692 {
693 	uint16_t	qflags = from->sb_qflags;
694 
695 	to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
696 
697 	/*
698 	 * The in-memory superblock quota state matches the v5 on-disk format so
699 	 * just write them out and return
700 	 */
701 	if (xfs_sb_is_v5(from)) {
702 		to->sb_qflags = cpu_to_be16(from->sb_qflags);
703 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
704 		to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
705 		return;
706 	}
707 
708 	/*
709 	 * For older superblocks (v4), the in-core version of sb_qflags do not
710 	 * have XFS_OQUOTA_* flags, whereas the on-disk version does.  So,
711 	 * convert incore XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
712 	 */
713 	qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
714 			XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
715 
716 	if (from->sb_qflags &
717 			(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
718 		qflags |= XFS_OQUOTA_ENFD;
719 	if (from->sb_qflags &
720 			(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
721 		qflags |= XFS_OQUOTA_CHKD;
722 	to->sb_qflags = cpu_to_be16(qflags);
723 
724 	/*
725 	 * GQUOTINO and PQUOTINO cannot be used together in versions
726 	 * of superblock that do not have pquotino. from->sb_flags
727 	 * tells us which quota is active and should be copied to
728 	 * disk. If neither are active, we should NULL the inode.
729 	 *
730 	 * In all cases, the separate pquotino must remain 0 because it
731 	 * is beyond the "end" of the valid non-pquotino superblock.
732 	 */
733 	if (from->sb_qflags & XFS_GQUOTA_ACCT)
734 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
735 	else if (from->sb_qflags & XFS_PQUOTA_ACCT)
736 		to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
737 	else {
738 		/*
739 		 * We can't rely on just the fields being logged to tell us
740 		 * that it is safe to write NULLFSINO - we should only do that
741 		 * if quotas are not actually enabled. Hence only write
742 		 * NULLFSINO if both in-core quota inodes are NULL.
743 		 */
744 		if (from->sb_gquotino == NULLFSINO &&
745 		    from->sb_pquotino == NULLFSINO)
746 			to->sb_gquotino = cpu_to_be64(NULLFSINO);
747 	}
748 
749 	to->sb_pquotino = 0;
750 }
751 
752 void
753 xfs_sb_to_disk(
754 	struct xfs_dsb	*to,
755 	struct xfs_sb	*from)
756 {
757 	xfs_sb_quota_to_disk(to, from);
758 
759 	to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
760 	to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
761 	to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
762 	to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
763 	to->sb_rextents = cpu_to_be64(from->sb_rextents);
764 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
765 	to->sb_logstart = cpu_to_be64(from->sb_logstart);
766 	to->sb_rootino = cpu_to_be64(from->sb_rootino);
767 	to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
768 	to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
769 	to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
770 	to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
771 	to->sb_agcount = cpu_to_be32(from->sb_agcount);
772 	to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
773 	to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
774 	to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
775 	to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
776 	to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
777 	to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
778 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
779 	to->sb_blocklog = from->sb_blocklog;
780 	to->sb_sectlog = from->sb_sectlog;
781 	to->sb_inodelog = from->sb_inodelog;
782 	to->sb_inopblog = from->sb_inopblog;
783 	to->sb_agblklog = from->sb_agblklog;
784 	to->sb_rextslog = from->sb_rextslog;
785 	to->sb_inprogress = from->sb_inprogress;
786 	to->sb_imax_pct = from->sb_imax_pct;
787 	to->sb_icount = cpu_to_be64(from->sb_icount);
788 	to->sb_ifree = cpu_to_be64(from->sb_ifree);
789 	to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
790 	to->sb_frextents = cpu_to_be64(from->sb_frextents);
791 
792 	to->sb_flags = from->sb_flags;
793 	to->sb_shared_vn = from->sb_shared_vn;
794 	to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
795 	to->sb_unit = cpu_to_be32(from->sb_unit);
796 	to->sb_width = cpu_to_be32(from->sb_width);
797 	to->sb_dirblklog = from->sb_dirblklog;
798 	to->sb_logsectlog = from->sb_logsectlog;
799 	to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
800 	to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
801 
802 	/*
803 	 * We need to ensure that bad_features2 always matches features2.
804 	 * Hence we enforce that here rather than having to remember to do it
805 	 * everywhere else that updates features2.
806 	 */
807 	from->sb_bad_features2 = from->sb_features2;
808 	to->sb_features2 = cpu_to_be32(from->sb_features2);
809 	to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
810 
811 	if (!xfs_sb_is_v5(from))
812 		return;
813 
814 	to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
815 	to->sb_features_ro_compat =
816 			cpu_to_be32(from->sb_features_ro_compat);
817 	to->sb_features_incompat =
818 			cpu_to_be32(from->sb_features_incompat);
819 	to->sb_features_log_incompat =
820 			cpu_to_be32(from->sb_features_log_incompat);
821 	to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
822 	to->sb_lsn = cpu_to_be64(from->sb_lsn);
823 	if (from->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
824 		uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
825 }
826 
827 /*
828  * If the superblock has the CRC feature bit set or the CRC field is non-null,
829  * check that the CRC is valid.  We check the CRC field is non-null because a
830  * single bit error could clear the feature bit and unused parts of the
831  * superblock are supposed to be zero. Hence a non-null crc field indicates that
832  * we've potentially lost a feature bit and we should check it anyway.
833  *
834  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
835  * last field in V4 secondary superblocks.  So for secondary superblocks,
836  * we are more forgiving, and ignore CRC failures if the primary doesn't
837  * indicate that the fs version is V5.
838  */
839 static void
840 xfs_sb_read_verify(
841 	struct xfs_buf		*bp)
842 {
843 	struct xfs_sb		sb;
844 	struct xfs_mount	*mp = bp->b_mount;
845 	struct xfs_dsb		*dsb = bp->b_addr;
846 	int			error;
847 
848 	/*
849 	 * open code the version check to avoid needing to convert the entire
850 	 * superblock from disk order just to check the version number
851 	 */
852 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
853 	    (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
854 						XFS_SB_VERSION_5) ||
855 	     dsb->sb_crc != 0)) {
856 
857 		if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
858 			/* Only fail bad secondaries on a known V5 filesystem */
859 			if (xfs_buf_daddr(bp) == XFS_SB_DADDR ||
860 			    xfs_has_crc(mp)) {
861 				error = -EFSBADCRC;
862 				goto out_error;
863 			}
864 		}
865 	}
866 
867 	/*
868 	 * Check all the superblock fields.  Don't byteswap the xquota flags
869 	 * because _verify_common checks the on-disk values.
870 	 */
871 	__xfs_sb_from_disk(&sb, dsb, false);
872 	error = xfs_validate_sb_common(mp, bp, &sb);
873 	if (error)
874 		goto out_error;
875 	error = xfs_validate_sb_read(mp, &sb);
876 
877 out_error:
878 	if (error == -EFSCORRUPTED || error == -EFSBADCRC)
879 		xfs_verifier_error(bp, error, __this_address);
880 	else if (error)
881 		xfs_buf_ioerror(bp, error);
882 }
883 
884 /*
885  * We may be probed for a filesystem match, so we may not want to emit
886  * messages when the superblock buffer is not actually an XFS superblock.
887  * If we find an XFS superblock, then run a normal, noisy mount because we are
888  * really going to mount it and want to know about errors.
889  */
890 static void
891 xfs_sb_quiet_read_verify(
892 	struct xfs_buf	*bp)
893 {
894 	struct xfs_dsb	*dsb = bp->b_addr;
895 
896 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
897 		/* XFS filesystem, verify noisily! */
898 		xfs_sb_read_verify(bp);
899 		return;
900 	}
901 	/* quietly fail */
902 	xfs_buf_ioerror(bp, -EWRONGFS);
903 }
904 
905 static void
906 xfs_sb_write_verify(
907 	struct xfs_buf		*bp)
908 {
909 	struct xfs_sb		sb;
910 	struct xfs_mount	*mp = bp->b_mount;
911 	struct xfs_buf_log_item	*bip = bp->b_log_item;
912 	struct xfs_dsb		*dsb = bp->b_addr;
913 	int			error;
914 
915 	/*
916 	 * Check all the superblock fields.  Don't byteswap the xquota flags
917 	 * because _verify_common checks the on-disk values.
918 	 */
919 	__xfs_sb_from_disk(&sb, dsb, false);
920 	error = xfs_validate_sb_common(mp, bp, &sb);
921 	if (error)
922 		goto out_error;
923 	error = xfs_validate_sb_write(mp, bp, &sb);
924 	if (error)
925 		goto out_error;
926 
927 	if (!xfs_sb_is_v5(&sb))
928 		return;
929 
930 	if (bip)
931 		dsb->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
932 
933 	xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
934 	return;
935 
936 out_error:
937 	xfs_verifier_error(bp, error, __this_address);
938 }
939 
940 const struct xfs_buf_ops xfs_sb_buf_ops = {
941 	.name = "xfs_sb",
942 	.magic = { cpu_to_be32(XFS_SB_MAGIC), cpu_to_be32(XFS_SB_MAGIC) },
943 	.verify_read = xfs_sb_read_verify,
944 	.verify_write = xfs_sb_write_verify,
945 };
946 
947 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
948 	.name = "xfs_sb_quiet",
949 	.magic = { cpu_to_be32(XFS_SB_MAGIC), cpu_to_be32(XFS_SB_MAGIC) },
950 	.verify_read = xfs_sb_quiet_read_verify,
951 	.verify_write = xfs_sb_write_verify,
952 };
953 
954 /*
955  * xfs_mount_common
956  *
957  * Mount initialization code establishing various mount
958  * fields from the superblock associated with the given
959  * mount structure.
960  *
961  * Inode geometry are calculated in xfs_ialloc_setup_geometry.
962  */
963 void
964 xfs_sb_mount_common(
965 	struct xfs_mount	*mp,
966 	struct xfs_sb		*sbp)
967 {
968 	mp->m_agfrotor = 0;
969 	atomic_set(&mp->m_agirotor, 0);
970 	mp->m_maxagi = mp->m_sb.sb_agcount;
971 	mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
972 	mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
973 	mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
974 	mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
975 	mp->m_blockmask = sbp->sb_blocksize - 1;
976 	mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
977 	mp->m_blockwmask = mp->m_blockwsize - 1;
978 
979 	mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
980 	mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
981 	mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
982 	mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
983 
984 	mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
985 	mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
986 	mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
987 	mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
988 
989 	mp->m_rmap_mxr[0] = xfs_rmapbt_maxrecs(sbp->sb_blocksize, 1);
990 	mp->m_rmap_mxr[1] = xfs_rmapbt_maxrecs(sbp->sb_blocksize, 0);
991 	mp->m_rmap_mnr[0] = mp->m_rmap_mxr[0] / 2;
992 	mp->m_rmap_mnr[1] = mp->m_rmap_mxr[1] / 2;
993 
994 	mp->m_refc_mxr[0] = xfs_refcountbt_maxrecs(sbp->sb_blocksize, true);
995 	mp->m_refc_mxr[1] = xfs_refcountbt_maxrecs(sbp->sb_blocksize, false);
996 	mp->m_refc_mnr[0] = mp->m_refc_mxr[0] / 2;
997 	mp->m_refc_mnr[1] = mp->m_refc_mxr[1] / 2;
998 
999 	mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
1000 	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
1001 	mp->m_ag_max_usable = xfs_alloc_ag_max_usable(mp);
1002 }
1003 
1004 /*
1005  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
1006  * into the superblock buffer to be logged.  It does not provide the higher
1007  * level of locking that is needed to protect the in-core superblock from
1008  * concurrent access.
1009  */
1010 void
1011 xfs_log_sb(
1012 	struct xfs_trans	*tp)
1013 {
1014 	struct xfs_mount	*mp = tp->t_mountp;
1015 	struct xfs_buf		*bp = xfs_trans_getsb(tp);
1016 
1017 	/*
1018 	 * Lazy sb counters don't update the in-core superblock so do that now.
1019 	 * If this is at unmount, the counters will be exactly correct, but at
1020 	 * any other time they will only be ballpark correct because of
1021 	 * reservations that have been taken out percpu counters. If we have an
1022 	 * unclean shutdown, this will be corrected by log recovery rebuilding
1023 	 * the counters from the AGF block counts.
1024 	 *
1025 	 * Do not update sb_frextents here because it is not part of the lazy
1026 	 * sb counters, despite having a percpu counter. It is always kept
1027 	 * consistent with the ondisk rtbitmap by xfs_trans_apply_sb_deltas()
1028 	 * and hence we don't need have to update it here.
1029 	 */
1030 	if (xfs_has_lazysbcount(mp)) {
1031 		mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount);
1032 		mp->m_sb.sb_ifree = min_t(uint64_t,
1033 				percpu_counter_sum(&mp->m_ifree),
1034 				mp->m_sb.sb_icount);
1035 		mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
1036 	}
1037 
1038 	xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
1039 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
1040 	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb) - 1);
1041 }
1042 
1043 /*
1044  * xfs_sync_sb
1045  *
1046  * Sync the superblock to disk.
1047  *
1048  * Note that the caller is responsible for checking the frozen state of the
1049  * filesystem. This procedure uses the non-blocking transaction allocator and
1050  * thus will allow modifications to a frozen fs. This is required because this
1051  * code can be called during the process of freezing where use of the high-level
1052  * allocator would deadlock.
1053  */
1054 int
1055 xfs_sync_sb(
1056 	struct xfs_mount	*mp,
1057 	bool			wait)
1058 {
1059 	struct xfs_trans	*tp;
1060 	int			error;
1061 
1062 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0,
1063 			XFS_TRANS_NO_WRITECOUNT, &tp);
1064 	if (error)
1065 		return error;
1066 
1067 	xfs_log_sb(tp);
1068 	if (wait)
1069 		xfs_trans_set_sync(tp);
1070 	return xfs_trans_commit(tp);
1071 }
1072 
1073 /*
1074  * Update all the secondary superblocks to match the new state of the primary.
1075  * Because we are completely overwriting all the existing fields in the
1076  * secondary superblock buffers, there is no need to read them in from disk.
1077  * Just get a new buffer, stamp it and write it.
1078  *
1079  * The sb buffers need to be cached here so that we serialise against other
1080  * operations that access the secondary superblocks, but we don't want to keep
1081  * them in memory once it is written so we mark it as a one-shot buffer.
1082  */
1083 int
1084 xfs_update_secondary_sbs(
1085 	struct xfs_mount	*mp)
1086 {
1087 	struct xfs_perag	*pag;
1088 	xfs_agnumber_t		agno = 1;
1089 	int			saved_error = 0;
1090 	int			error = 0;
1091 	LIST_HEAD		(buffer_list);
1092 
1093 	/* update secondary superblocks. */
1094 	for_each_perag_from(mp, agno, pag) {
1095 		struct xfs_buf		*bp;
1096 
1097 		error = xfs_buf_get(mp->m_ddev_targp,
1098 				 XFS_AG_DADDR(mp, pag->pag_agno, XFS_SB_DADDR),
1099 				 XFS_FSS_TO_BB(mp, 1), &bp);
1100 		/*
1101 		 * If we get an error reading or writing alternate superblocks,
1102 		 * continue.  xfs_repair chooses the "best" superblock based
1103 		 * on most matches; if we break early, we'll leave more
1104 		 * superblocks un-updated than updated, and xfs_repair may
1105 		 * pick them over the properly-updated primary.
1106 		 */
1107 		if (error) {
1108 			xfs_warn(mp,
1109 		"error allocating secondary superblock for ag %d",
1110 				pag->pag_agno);
1111 			if (!saved_error)
1112 				saved_error = error;
1113 			continue;
1114 		}
1115 
1116 		bp->b_ops = &xfs_sb_buf_ops;
1117 		xfs_buf_oneshot(bp);
1118 		xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
1119 		xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
1120 		xfs_buf_delwri_queue(bp, &buffer_list);
1121 		xfs_buf_relse(bp);
1122 
1123 		/* don't hold too many buffers at once */
1124 		if (agno % 16)
1125 			continue;
1126 
1127 		error = xfs_buf_delwri_submit(&buffer_list);
1128 		if (error) {
1129 			xfs_warn(mp,
1130 		"write error %d updating a secondary superblock near ag %d",
1131 				error, pag->pag_agno);
1132 			if (!saved_error)
1133 				saved_error = error;
1134 			continue;
1135 		}
1136 	}
1137 	error = xfs_buf_delwri_submit(&buffer_list);
1138 	if (error) {
1139 		xfs_warn(mp,
1140 		"write error %d updating a secondary superblock near ag %d",
1141 			error, agno);
1142 	}
1143 
1144 	return saved_error ? saved_error : error;
1145 }
1146 
1147 /*
1148  * Same behavior as xfs_sync_sb, except that it is always synchronous and it
1149  * also writes the superblock buffer to disk sector 0 immediately.
1150  */
1151 int
1152 xfs_sync_sb_buf(
1153 	struct xfs_mount	*mp)
1154 {
1155 	struct xfs_trans	*tp;
1156 	struct xfs_buf		*bp;
1157 	int			error;
1158 
1159 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0, 0, &tp);
1160 	if (error)
1161 		return error;
1162 
1163 	bp = xfs_trans_getsb(tp);
1164 	xfs_log_sb(tp);
1165 	xfs_trans_bhold(tp, bp);
1166 	xfs_trans_set_sync(tp);
1167 	error = xfs_trans_commit(tp);
1168 	if (error)
1169 		goto out;
1170 	/*
1171 	 * write out the sb buffer to get the changes to disk
1172 	 */
1173 	error = xfs_bwrite(bp);
1174 out:
1175 	xfs_buf_relse(bp);
1176 	return error;
1177 }
1178 
1179 void
1180 xfs_fs_geometry(
1181 	struct xfs_mount	*mp,
1182 	struct xfs_fsop_geom	*geo,
1183 	int			struct_version)
1184 {
1185 	struct xfs_sb		*sbp = &mp->m_sb;
1186 
1187 	memset(geo, 0, sizeof(struct xfs_fsop_geom));
1188 
1189 	geo->blocksize = sbp->sb_blocksize;
1190 	geo->rtextsize = sbp->sb_rextsize;
1191 	geo->agblocks = sbp->sb_agblocks;
1192 	geo->agcount = sbp->sb_agcount;
1193 	geo->logblocks = sbp->sb_logblocks;
1194 	geo->sectsize = sbp->sb_sectsize;
1195 	geo->inodesize = sbp->sb_inodesize;
1196 	geo->imaxpct = sbp->sb_imax_pct;
1197 	geo->datablocks = sbp->sb_dblocks;
1198 	geo->rtblocks = sbp->sb_rblocks;
1199 	geo->rtextents = sbp->sb_rextents;
1200 	geo->logstart = sbp->sb_logstart;
1201 	BUILD_BUG_ON(sizeof(geo->uuid) != sizeof(sbp->sb_uuid));
1202 	memcpy(geo->uuid, &sbp->sb_uuid, sizeof(sbp->sb_uuid));
1203 
1204 	if (struct_version < 2)
1205 		return;
1206 
1207 	geo->sunit = sbp->sb_unit;
1208 	geo->swidth = sbp->sb_width;
1209 
1210 	if (struct_version < 3)
1211 		return;
1212 
1213 	geo->version = XFS_FSOP_GEOM_VERSION;
1214 	geo->flags = XFS_FSOP_GEOM_FLAGS_NLINK |
1215 		     XFS_FSOP_GEOM_FLAGS_DIRV2 |
1216 		     XFS_FSOP_GEOM_FLAGS_EXTFLG;
1217 	if (xfs_has_attr(mp))
1218 		geo->flags |= XFS_FSOP_GEOM_FLAGS_ATTR;
1219 	if (xfs_has_quota(mp))
1220 		geo->flags |= XFS_FSOP_GEOM_FLAGS_QUOTA;
1221 	if (xfs_has_align(mp))
1222 		geo->flags |= XFS_FSOP_GEOM_FLAGS_IALIGN;
1223 	if (xfs_has_dalign(mp))
1224 		geo->flags |= XFS_FSOP_GEOM_FLAGS_DALIGN;
1225 	if (xfs_has_asciici(mp))
1226 		geo->flags |= XFS_FSOP_GEOM_FLAGS_DIRV2CI;
1227 	if (xfs_has_lazysbcount(mp))
1228 		geo->flags |= XFS_FSOP_GEOM_FLAGS_LAZYSB;
1229 	if (xfs_has_attr2(mp))
1230 		geo->flags |= XFS_FSOP_GEOM_FLAGS_ATTR2;
1231 	if (xfs_has_projid32(mp))
1232 		geo->flags |= XFS_FSOP_GEOM_FLAGS_PROJID32;
1233 	if (xfs_has_crc(mp))
1234 		geo->flags |= XFS_FSOP_GEOM_FLAGS_V5SB;
1235 	if (xfs_has_ftype(mp))
1236 		geo->flags |= XFS_FSOP_GEOM_FLAGS_FTYPE;
1237 	if (xfs_has_finobt(mp))
1238 		geo->flags |= XFS_FSOP_GEOM_FLAGS_FINOBT;
1239 	if (xfs_has_sparseinodes(mp))
1240 		geo->flags |= XFS_FSOP_GEOM_FLAGS_SPINODES;
1241 	if (xfs_has_rmapbt(mp))
1242 		geo->flags |= XFS_FSOP_GEOM_FLAGS_RMAPBT;
1243 	if (xfs_has_reflink(mp))
1244 		geo->flags |= XFS_FSOP_GEOM_FLAGS_REFLINK;
1245 	if (xfs_has_bigtime(mp))
1246 		geo->flags |= XFS_FSOP_GEOM_FLAGS_BIGTIME;
1247 	if (xfs_has_inobtcounts(mp))
1248 		geo->flags |= XFS_FSOP_GEOM_FLAGS_INOBTCNT;
1249 	if (xfs_has_sector(mp)) {
1250 		geo->flags |= XFS_FSOP_GEOM_FLAGS_SECTOR;
1251 		geo->logsectsize = sbp->sb_logsectsize;
1252 	} else {
1253 		geo->logsectsize = BBSIZE;
1254 	}
1255 	if (xfs_has_large_extent_counts(mp))
1256 		geo->flags |= XFS_FSOP_GEOM_FLAGS_NREXT64;
1257 	geo->rtsectsize = sbp->sb_blocksize;
1258 	geo->dirblocksize = xfs_dir2_dirblock_bytes(sbp);
1259 
1260 	if (struct_version < 4)
1261 		return;
1262 
1263 	if (xfs_has_logv2(mp))
1264 		geo->flags |= XFS_FSOP_GEOM_FLAGS_LOGV2;
1265 
1266 	geo->logsunit = sbp->sb_logsunit;
1267 
1268 	if (struct_version < 5)
1269 		return;
1270 
1271 	geo->version = XFS_FSOP_GEOM_VERSION_V5;
1272 }
1273 
1274 /* Read a secondary superblock. */
1275 int
1276 xfs_sb_read_secondary(
1277 	struct xfs_mount	*mp,
1278 	struct xfs_trans	*tp,
1279 	xfs_agnumber_t		agno,
1280 	struct xfs_buf		**bpp)
1281 {
1282 	struct xfs_buf		*bp;
1283 	int			error;
1284 
1285 	ASSERT(agno != 0 && agno != NULLAGNUMBER);
1286 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
1287 			XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
1288 			XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops);
1289 	if (error)
1290 		return error;
1291 	xfs_buf_set_ref(bp, XFS_SSB_REF);
1292 	*bpp = bp;
1293 	return 0;
1294 }
1295 
1296 /* Get an uninitialised secondary superblock buffer. */
1297 int
1298 xfs_sb_get_secondary(
1299 	struct xfs_mount	*mp,
1300 	struct xfs_trans	*tp,
1301 	xfs_agnumber_t		agno,
1302 	struct xfs_buf		**bpp)
1303 {
1304 	struct xfs_buf		*bp;
1305 	int			error;
1306 
1307 	ASSERT(agno != 0 && agno != NULLAGNUMBER);
1308 	error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
1309 			XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
1310 			XFS_FSS_TO_BB(mp, 1), 0, &bp);
1311 	if (error)
1312 		return error;
1313 	bp->b_ops = &xfs_sb_buf_ops;
1314 	xfs_buf_oneshot(bp);
1315 	*bpp = bp;
1316 	return 0;
1317 }
1318 
1319 /*
1320  * sunit, swidth, sectorsize(optional with 0) should be all in bytes,
1321  * so users won't be confused by values in error messages.
1322  */
1323 bool
1324 xfs_validate_stripe_geometry(
1325 	struct xfs_mount	*mp,
1326 	__s64			sunit,
1327 	__s64			swidth,
1328 	int			sectorsize,
1329 	bool			silent)
1330 {
1331 	if (swidth > INT_MAX) {
1332 		if (!silent)
1333 			xfs_notice(mp,
1334 "stripe width (%lld) is too large", swidth);
1335 		return false;
1336 	}
1337 
1338 	if (sunit > swidth) {
1339 		if (!silent)
1340 			xfs_notice(mp,
1341 "stripe unit (%lld) is larger than the stripe width (%lld)", sunit, swidth);
1342 		return false;
1343 	}
1344 
1345 	if (sectorsize && (int)sunit % sectorsize) {
1346 		if (!silent)
1347 			xfs_notice(mp,
1348 "stripe unit (%lld) must be a multiple of the sector size (%d)",
1349 				   sunit, sectorsize);
1350 		return false;
1351 	}
1352 
1353 	if (sunit && !swidth) {
1354 		if (!silent)
1355 			xfs_notice(mp,
1356 "invalid stripe unit (%lld) and stripe width of 0", sunit);
1357 		return false;
1358 	}
1359 
1360 	if (!sunit && swidth) {
1361 		if (!silent)
1362 			xfs_notice(mp,
1363 "invalid stripe width (%lld) and stripe unit of 0", swidth);
1364 		return false;
1365 	}
1366 
1367 	if (sunit && (int)swidth % (int)sunit) {
1368 		if (!silent)
1369 			xfs_notice(mp,
1370 "stripe width (%lld) must be a multiple of the stripe unit (%lld)",
1371 				   swidth, sunit);
1372 		return false;
1373 	}
1374 	return true;
1375 }
1376