xref: /openbmc/linux/fs/xfs/libxfs/xfs_sb.c (revision 49c23519)
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 
30 /*
31  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
32  */
33 
34 /*
35  * Check that all the V4 feature bits that the V5 filesystem format requires are
36  * correctly set.
37  */
38 static bool
39 xfs_sb_validate_v5_features(
40 	struct xfs_sb	*sbp)
41 {
42 	/* We must not have any unknown V4 feature bits set */
43 	if (sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS)
44 		return false;
45 
46 	/*
47 	 * The CRC bit is considered an invalid V4 flag, so we have to add it
48 	 * manually to the OKBITS mask.
49 	 */
50 	if (sbp->sb_features2 & ~(XFS_SB_VERSION2_OKBITS |
51 				  XFS_SB_VERSION2_CRCBIT))
52 		return false;
53 
54 	/* Now check all the required V4 feature flags are set. */
55 
56 #define V5_VERS_FLAGS	(XFS_SB_VERSION_NLINKBIT	| \
57 			XFS_SB_VERSION_ALIGNBIT		| \
58 			XFS_SB_VERSION_LOGV2BIT		| \
59 			XFS_SB_VERSION_EXTFLGBIT	| \
60 			XFS_SB_VERSION_DIRV2BIT		| \
61 			XFS_SB_VERSION_MOREBITSBIT)
62 
63 #define V5_FEAT_FLAGS	(XFS_SB_VERSION2_LAZYSBCOUNTBIT	| \
64 			XFS_SB_VERSION2_ATTR2BIT	| \
65 			XFS_SB_VERSION2_PROJID32BIT	| \
66 			XFS_SB_VERSION2_CRCBIT)
67 
68 	if ((sbp->sb_versionnum & V5_VERS_FLAGS) != V5_VERS_FLAGS)
69 		return false;
70 	if ((sbp->sb_features2 & V5_FEAT_FLAGS) != V5_FEAT_FLAGS)
71 		return false;
72 	return true;
73 }
74 
75 /*
76  * We current support XFS v5 formats with known features and v4 superblocks with
77  * at least V2 directories.
78  */
79 bool
80 xfs_sb_good_version(
81 	struct xfs_sb	*sbp)
82 {
83 	/*
84 	 * All v5 filesystems are supported, but we must check that all the
85 	 * required v4 feature flags are enabled correctly as the code checks
86 	 * those flags and not for v5 support.
87 	 */
88 	if (xfs_sb_is_v5(sbp))
89 		return xfs_sb_validate_v5_features(sbp);
90 
91 	/* versions prior to v4 are not supported */
92 	if (XFS_SB_VERSION_NUM(sbp) != XFS_SB_VERSION_4)
93 		return false;
94 
95 	/* We must not have any unknown v4 feature bits set */
96 	if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
97 	    ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
98 	     (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS)))
99 		return false;
100 
101 	/* V4 filesystems need v2 directories and unwritten extents */
102 	if (!(sbp->sb_versionnum & XFS_SB_VERSION_DIRV2BIT))
103 		return false;
104 	if (!(sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT))
105 		return false;
106 
107 	/* It's a supported v4 filesystem */
108 	return true;
109 }
110 
111 uint64_t
112 xfs_sb_version_to_features(
113 	struct xfs_sb	*sbp)
114 {
115 	uint64_t	features = 0;
116 
117 	/* optional V4 features */
118 	if (sbp->sb_rblocks > 0)
119 		features |= XFS_FEAT_REALTIME;
120 	if (sbp->sb_versionnum & XFS_SB_VERSION_NLINKBIT)
121 		features |= XFS_FEAT_NLINK;
122 	if (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT)
123 		features |= XFS_FEAT_ATTR;
124 	if (sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT)
125 		features |= XFS_FEAT_QUOTA;
126 	if (sbp->sb_versionnum & XFS_SB_VERSION_ALIGNBIT)
127 		features |= XFS_FEAT_ALIGN;
128 	if (sbp->sb_versionnum & XFS_SB_VERSION_LOGV2BIT)
129 		features |= XFS_FEAT_LOGV2;
130 	if (sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT)
131 		features |= XFS_FEAT_DALIGN;
132 	if (sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT)
133 		features |= XFS_FEAT_EXTFLG;
134 	if (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT)
135 		features |= XFS_FEAT_SECTOR;
136 	if (sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT)
137 		features |= XFS_FEAT_ASCIICI;
138 	if (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) {
139 		if (sbp->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT)
140 			features |= XFS_FEAT_LAZYSBCOUNT;
141 		if (sbp->sb_features2 & XFS_SB_VERSION2_ATTR2BIT)
142 			features |= XFS_FEAT_ATTR2;
143 		if (sbp->sb_features2 & XFS_SB_VERSION2_PROJID32BIT)
144 			features |= XFS_FEAT_PROJID32;
145 		if (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE)
146 			features |= XFS_FEAT_FTYPE;
147 	}
148 
149 	if (!xfs_sb_is_v5(sbp))
150 		return features;
151 
152 	/* Always on V5 features */
153 	features |= XFS_FEAT_ALIGN | XFS_FEAT_LOGV2 | XFS_FEAT_EXTFLG |
154 		    XFS_FEAT_LAZYSBCOUNT | XFS_FEAT_ATTR2 | XFS_FEAT_PROJID32 |
155 		    XFS_FEAT_V3INODES | XFS_FEAT_CRC | XFS_FEAT_PQUOTINO;
156 
157 	/* Optional V5 features */
158 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT)
159 		features |= XFS_FEAT_FINOBT;
160 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT)
161 		features |= XFS_FEAT_RMAPBT;
162 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_REFLINK)
163 		features |= XFS_FEAT_REFLINK;
164 	if (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_INOBTCNT)
165 		features |= XFS_FEAT_INOBTCNT;
166 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_FTYPE)
167 		features |= XFS_FEAT_FTYPE;
168 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES)
169 		features |= XFS_FEAT_SPINODES;
170 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
171 		features |= XFS_FEAT_META_UUID;
172 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_BIGTIME)
173 		features |= XFS_FEAT_BIGTIME;
174 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
175 		features |= XFS_FEAT_NEEDSREPAIR;
176 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
177 		features |= XFS_FEAT_NREXT64;
178 
179 	return features;
180 }
181 
182 /* Check all the superblock fields we care about when reading one in. */
183 STATIC int
184 xfs_validate_sb_read(
185 	struct xfs_mount	*mp,
186 	struct xfs_sb		*sbp)
187 {
188 	if (!xfs_sb_is_v5(sbp))
189 		return 0;
190 
191 	/*
192 	 * Version 5 superblock feature mask validation. Reject combinations
193 	 * the kernel cannot support up front before checking anything else.
194 	 */
195 	if (xfs_sb_has_compat_feature(sbp, XFS_SB_FEAT_COMPAT_UNKNOWN)) {
196 		xfs_warn(mp,
197 "Superblock has unknown compatible features (0x%x) enabled.",
198 			(sbp->sb_features_compat & XFS_SB_FEAT_COMPAT_UNKNOWN));
199 		xfs_warn(mp,
200 "Using a more recent kernel is recommended.");
201 	}
202 
203 	if (xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
204 		xfs_alert(mp,
205 "Superblock has unknown read-only compatible features (0x%x) enabled.",
206 			(sbp->sb_features_ro_compat &
207 					XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
208 		if (!xfs_is_readonly(mp)) {
209 			xfs_warn(mp,
210 "Attempted to mount read-only compatible filesystem read-write.");
211 			xfs_warn(mp,
212 "Filesystem can only be safely mounted read only.");
213 
214 			return -EINVAL;
215 		}
216 	}
217 	if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
218 		xfs_warn(mp,
219 "Superblock has unknown incompatible features (0x%x) enabled.",
220 			(sbp->sb_features_incompat &
221 					XFS_SB_FEAT_INCOMPAT_UNKNOWN));
222 		xfs_warn(mp,
223 "Filesystem cannot be safely mounted by this kernel.");
224 		return -EINVAL;
225 	}
226 
227 	return 0;
228 }
229 
230 /* Check all the superblock fields we care about when writing one out. */
231 STATIC int
232 xfs_validate_sb_write(
233 	struct xfs_mount	*mp,
234 	struct xfs_buf		*bp,
235 	struct xfs_sb		*sbp)
236 {
237 	/*
238 	 * Carry out additional sb summary counter sanity checks when we write
239 	 * the superblock.  We skip this in the read validator because there
240 	 * could be newer superblocks in the log and if the values are garbage
241 	 * even after replay we'll recalculate them at the end of log mount.
242 	 *
243 	 * mkfs has traditionally written zeroed counters to inprogress and
244 	 * secondary superblocks, so allow this usage to continue because
245 	 * we never read counters from such superblocks.
246 	 */
247 	if (xfs_buf_daddr(bp) == XFS_SB_DADDR && !sbp->sb_inprogress &&
248 	    (sbp->sb_fdblocks > sbp->sb_dblocks ||
249 	     !xfs_verify_icount(mp, sbp->sb_icount) ||
250 	     sbp->sb_ifree > sbp->sb_icount)) {
251 		xfs_warn(mp, "SB summary counter sanity check failed");
252 		return -EFSCORRUPTED;
253 	}
254 
255 	if (!xfs_sb_is_v5(sbp))
256 		return 0;
257 
258 	/*
259 	 * Version 5 superblock feature mask validation. Reject combinations
260 	 * the kernel cannot support since we checked for unsupported bits in
261 	 * the read verifier, which means that memory is corrupt.
262 	 */
263 	if (xfs_sb_has_compat_feature(sbp, XFS_SB_FEAT_COMPAT_UNKNOWN)) {
264 		xfs_warn(mp,
265 "Corruption detected in superblock compatible features (0x%x)!",
266 			(sbp->sb_features_compat & XFS_SB_FEAT_COMPAT_UNKNOWN));
267 		return -EFSCORRUPTED;
268 	}
269 
270 	if (!xfs_is_readonly(mp) &&
271 	    xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
272 		xfs_alert(mp,
273 "Corruption detected in superblock read-only compatible features (0x%x)!",
274 			(sbp->sb_features_ro_compat &
275 					XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
276 		return -EFSCORRUPTED;
277 	}
278 	if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
279 		xfs_warn(mp,
280 "Corruption detected in superblock incompatible features (0x%x)!",
281 			(sbp->sb_features_incompat &
282 					XFS_SB_FEAT_INCOMPAT_UNKNOWN));
283 		return -EFSCORRUPTED;
284 	}
285 	if (xfs_sb_has_incompat_log_feature(sbp,
286 			XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) {
287 		xfs_warn(mp,
288 "Corruption detected in superblock incompatible log features (0x%x)!",
289 			(sbp->sb_features_log_incompat &
290 					XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));
291 		return -EFSCORRUPTED;
292 	}
293 
294 	/*
295 	 * We can't read verify the sb LSN because the read verifier is called
296 	 * before the log is allocated and processed. We know the log is set up
297 	 * before write verifier calls, so check it here.
298 	 */
299 	if (!xfs_log_check_lsn(mp, sbp->sb_lsn))
300 		return -EFSCORRUPTED;
301 
302 	return 0;
303 }
304 
305 /* Check the validity of the SB. */
306 STATIC int
307 xfs_validate_sb_common(
308 	struct xfs_mount	*mp,
309 	struct xfs_buf		*bp,
310 	struct xfs_sb		*sbp)
311 {
312 	struct xfs_dsb		*dsb = bp->b_addr;
313 	uint32_t		agcount = 0;
314 	uint32_t		rem;
315 	bool			has_dalign;
316 
317 	if (!xfs_verify_magic(bp, dsb->sb_magicnum)) {
318 		xfs_warn(mp,
319 "Superblock has bad magic number 0x%x. Not an XFS filesystem?",
320 			be32_to_cpu(dsb->sb_magicnum));
321 		return -EWRONGFS;
322 	}
323 
324 	if (!xfs_sb_good_version(sbp)) {
325 		xfs_warn(mp,
326 "Superblock has unknown features enabled or corrupted feature masks.");
327 		return -EWRONGFS;
328 	}
329 
330 	/*
331 	 * Validate feature flags and state
332 	 */
333 	if (xfs_sb_is_v5(sbp)) {
334 		if (sbp->sb_blocksize < XFS_MIN_CRC_BLOCKSIZE) {
335 			xfs_notice(mp,
336 "Block size (%u bytes) too small for Version 5 superblock (minimum %d bytes)",
337 				sbp->sb_blocksize, XFS_MIN_CRC_BLOCKSIZE);
338 			return -EFSCORRUPTED;
339 		}
340 
341 		/* V5 has a separate project quota inode */
342 		if (sbp->sb_qflags & (XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD)) {
343 			xfs_notice(mp,
344 			   "Version 5 of Super block has XFS_OQUOTA bits.");
345 			return -EFSCORRUPTED;
346 		}
347 
348 		/*
349 		 * Full inode chunks must be aligned to inode chunk size when
350 		 * sparse inodes are enabled to support the sparse chunk
351 		 * allocation algorithm and prevent overlapping inode records.
352 		 */
353 		if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_SPINODES) {
354 			uint32_t	align;
355 
356 			align = XFS_INODES_PER_CHUNK * sbp->sb_inodesize
357 					>> sbp->sb_blocklog;
358 			if (sbp->sb_inoalignmt != align) {
359 				xfs_warn(mp,
360 "Inode block alignment (%u) must match chunk size (%u) for sparse inodes.",
361 					 sbp->sb_inoalignmt, align);
362 				return -EINVAL;
363 			}
364 		}
365 	} else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
366 				XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
367 			xfs_notice(mp,
368 "Superblock earlier than Version 5 has XFS_{P|G}QUOTA_{ENFD|CHKD} bits.");
369 			return -EFSCORRUPTED;
370 	}
371 
372 	if (unlikely(
373 	    sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
374 		xfs_warn(mp,
375 		"filesystem is marked as having an external log; "
376 		"specify logdev on the mount command line.");
377 		return -EINVAL;
378 	}
379 
380 	if (unlikely(
381 	    sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
382 		xfs_warn(mp,
383 		"filesystem is marked as having an internal log; "
384 		"do not specify logdev on the mount command line.");
385 		return -EINVAL;
386 	}
387 
388 	/* Compute agcount for this number of dblocks and agblocks */
389 	if (sbp->sb_agblocks) {
390 		agcount = div_u64_rem(sbp->sb_dblocks, sbp->sb_agblocks, &rem);
391 		if (rem)
392 			agcount++;
393 	}
394 
395 	/*
396 	 * More sanity checking.  Most of these were stolen directly from
397 	 * xfs_repair.
398 	 */
399 	if (unlikely(
400 	    sbp->sb_agcount <= 0					||
401 	    sbp->sb_sectsize < XFS_MIN_SECTORSIZE			||
402 	    sbp->sb_sectsize > XFS_MAX_SECTORSIZE			||
403 	    sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG			||
404 	    sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG			||
405 	    sbp->sb_sectsize != (1 << sbp->sb_sectlog)			||
406 	    sbp->sb_blocksize < XFS_MIN_BLOCKSIZE			||
407 	    sbp->sb_blocksize > XFS_MAX_BLOCKSIZE			||
408 	    sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG			||
409 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
410 	    sbp->sb_blocksize != (1 << sbp->sb_blocklog)		||
411 	    sbp->sb_dirblklog + sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
412 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
413 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
414 	    sbp->sb_inodelog < XFS_DINODE_MIN_LOG			||
415 	    sbp->sb_inodelog > XFS_DINODE_MAX_LOG			||
416 	    sbp->sb_inodesize != (1 << sbp->sb_inodelog)		||
417 	    sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
418 	    XFS_FSB_TO_B(mp, sbp->sb_agblocks) < XFS_MIN_AG_BYTES	||
419 	    XFS_FSB_TO_B(mp, sbp->sb_agblocks) > XFS_MAX_AG_BYTES	||
420 	    sbp->sb_agblklog != xfs_highbit32(sbp->sb_agblocks - 1) + 1	||
421 	    agcount == 0 || agcount != sbp->sb_agcount			||
422 	    (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)	||
423 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
424 	    (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)	||
425 	    (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)	||
426 	    sbp->sb_dblocks == 0					||
427 	    sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)			||
428 	    sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)			||
429 	    sbp->sb_shared_vn != 0)) {
430 		xfs_notice(mp, "SB sanity check failed");
431 		return -EFSCORRUPTED;
432 	}
433 
434 	/*
435 	 * Logs that are too large are not supported at all. Reject them
436 	 * outright. Logs that are too small are tolerated on v4 filesystems,
437 	 * but we can only check that when mounting the log. Hence we skip
438 	 * those checks here.
439 	 */
440 	if (sbp->sb_logblocks > XFS_MAX_LOG_BLOCKS) {
441 		xfs_notice(mp,
442 		"Log size 0x%x blocks too large, maximum size is 0x%llx blocks",
443 			 sbp->sb_logblocks, XFS_MAX_LOG_BLOCKS);
444 		return -EFSCORRUPTED;
445 	}
446 
447 	if (XFS_FSB_TO_B(mp, sbp->sb_logblocks) > XFS_MAX_LOG_BYTES) {
448 		xfs_warn(mp,
449 		"log size 0x%llx bytes too large, maximum size is 0x%llx bytes",
450 			 XFS_FSB_TO_B(mp, sbp->sb_logblocks),
451 			 XFS_MAX_LOG_BYTES);
452 		return -EFSCORRUPTED;
453 	}
454 
455 	/*
456 	 * Do not allow filesystems with corrupted log sector or stripe units to
457 	 * be mounted. We cannot safely size the iclogs or write to the log if
458 	 * the log stripe unit is not valid.
459 	 */
460 	if (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT) {
461 		if (sbp->sb_logsectsize != (1U << sbp->sb_logsectlog)) {
462 			xfs_notice(mp,
463 			"log sector size in bytes/log2 (0x%x/0x%x) must match",
464 				sbp->sb_logsectsize, 1U << sbp->sb_logsectlog);
465 			return -EFSCORRUPTED;
466 		}
467 	} else if (sbp->sb_logsectsize || sbp->sb_logsectlog) {
468 		xfs_notice(mp,
469 		"log sector size in bytes/log2 (0x%x/0x%x) are not zero",
470 			sbp->sb_logsectsize, sbp->sb_logsectlog);
471 		return -EFSCORRUPTED;
472 	}
473 
474 	if (sbp->sb_logsunit > 1) {
475 		if (sbp->sb_logsunit % sbp->sb_blocksize) {
476 			xfs_notice(mp,
477 		"log stripe unit 0x%x bytes must be a multiple of block size",
478 				sbp->sb_logsunit);
479 			return -EFSCORRUPTED;
480 		}
481 		if (sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE) {
482 			xfs_notice(mp,
483 		"log stripe unit 0x%x bytes over maximum size (0x%x bytes)",
484 				sbp->sb_logsunit, XLOG_MAX_RECORD_BSIZE);
485 			return -EFSCORRUPTED;
486 		}
487 	}
488 
489 	/* Validate the realtime geometry; stolen from xfs_repair */
490 	if (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE ||
491 	    sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) {
492 		xfs_notice(mp,
493 			"realtime extent sanity check failed");
494 		return -EFSCORRUPTED;
495 	}
496 
497 	if (sbp->sb_rblocks == 0) {
498 		if (sbp->sb_rextents != 0 || sbp->sb_rbmblocks != 0 ||
499 		    sbp->sb_rextslog != 0 || sbp->sb_frextents != 0) {
500 			xfs_notice(mp,
501 				"realtime zeroed geometry check failed");
502 			return -EFSCORRUPTED;
503 		}
504 	} else {
505 		uint64_t	rexts;
506 		uint64_t	rbmblocks;
507 
508 		rexts = div_u64(sbp->sb_rblocks, sbp->sb_rextsize);
509 		rbmblocks = howmany_64(sbp->sb_rextents,
510 				       NBBY * sbp->sb_blocksize);
511 
512 		if (!xfs_validate_rtextents(rexts) ||
513 		    sbp->sb_rextents != rexts ||
514 		    sbp->sb_rextslog != xfs_compute_rextslog(rexts) ||
515 		    sbp->sb_rbmblocks != rbmblocks) {
516 			xfs_notice(mp,
517 				"realtime geometry sanity check failed");
518 			return -EFSCORRUPTED;
519 		}
520 	}
521 
522 	/*
523 	 * Either (sb_unit and !hasdalign) or (!sb_unit and hasdalign)
524 	 * would imply the image is corrupted.
525 	 */
526 	has_dalign = sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT;
527 	if (!!sbp->sb_unit ^ has_dalign) {
528 		xfs_notice(mp, "SB stripe alignment sanity check failed");
529 		return -EFSCORRUPTED;
530 	}
531 
532 	if (!xfs_validate_stripe_geometry(mp, XFS_FSB_TO_B(mp, sbp->sb_unit),
533 			XFS_FSB_TO_B(mp, sbp->sb_width), 0, false))
534 		return -EFSCORRUPTED;
535 
536 	/*
537 	 * Currently only very few inode sizes are supported.
538 	 */
539 	switch (sbp->sb_inodesize) {
540 	case 256:
541 	case 512:
542 	case 1024:
543 	case 2048:
544 		break;
545 	default:
546 		xfs_warn(mp, "inode size of %d bytes not supported",
547 				sbp->sb_inodesize);
548 		return -ENOSYS;
549 	}
550 
551 	return 0;
552 }
553 
554 void
555 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
556 {
557 	/*
558 	 * older mkfs doesn't initialize quota inodes to NULLFSINO. This
559 	 * leads to in-core values having two different values for a quota
560 	 * inode to be invalid: 0 and NULLFSINO. Change it to a single value
561 	 * NULLFSINO.
562 	 *
563 	 * Note that this change affect only the in-core values. These
564 	 * values are not written back to disk unless any quota information
565 	 * is written to the disk. Even in that case, sb_pquotino field is
566 	 * not written to disk unless the superblock supports pquotino.
567 	 */
568 	if (sbp->sb_uquotino == 0)
569 		sbp->sb_uquotino = NULLFSINO;
570 	if (sbp->sb_gquotino == 0)
571 		sbp->sb_gquotino = NULLFSINO;
572 	if (sbp->sb_pquotino == 0)
573 		sbp->sb_pquotino = NULLFSINO;
574 
575 	/*
576 	 * We need to do these manipilations only if we are working
577 	 * with an older version of on-disk superblock.
578 	 */
579 	if (xfs_sb_is_v5(sbp))
580 		return;
581 
582 	if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
583 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
584 					XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
585 	if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
586 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
587 					XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
588 	sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
589 
590 	if (sbp->sb_qflags & XFS_PQUOTA_ACCT &&
591 	    sbp->sb_gquotino != NULLFSINO)  {
592 		/*
593 		 * In older version of superblock, on-disk superblock only
594 		 * has sb_gquotino, and in-core superblock has both sb_gquotino
595 		 * and sb_pquotino. But, only one of them is supported at any
596 		 * point of time. So, if PQUOTA is set in disk superblock,
597 		 * copy over sb_gquotino to sb_pquotino.  The NULLFSINO test
598 		 * above is to make sure we don't do this twice and wipe them
599 		 * both out!
600 		 */
601 		sbp->sb_pquotino = sbp->sb_gquotino;
602 		sbp->sb_gquotino = NULLFSINO;
603 	}
604 }
605 
606 static void
607 __xfs_sb_from_disk(
608 	struct xfs_sb	*to,
609 	struct xfs_dsb	*from,
610 	bool		convert_xquota)
611 {
612 	to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
613 	to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
614 	to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
615 	to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
616 	to->sb_rextents = be64_to_cpu(from->sb_rextents);
617 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
618 	to->sb_logstart = be64_to_cpu(from->sb_logstart);
619 	to->sb_rootino = be64_to_cpu(from->sb_rootino);
620 	to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
621 	to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
622 	to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
623 	to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
624 	to->sb_agcount = be32_to_cpu(from->sb_agcount);
625 	to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
626 	to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
627 	to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
628 	to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
629 	to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
630 	to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
631 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
632 	to->sb_blocklog = from->sb_blocklog;
633 	to->sb_sectlog = from->sb_sectlog;
634 	to->sb_inodelog = from->sb_inodelog;
635 	to->sb_inopblog = from->sb_inopblog;
636 	to->sb_agblklog = from->sb_agblklog;
637 	to->sb_rextslog = from->sb_rextslog;
638 	to->sb_inprogress = from->sb_inprogress;
639 	to->sb_imax_pct = from->sb_imax_pct;
640 	to->sb_icount = be64_to_cpu(from->sb_icount);
641 	to->sb_ifree = be64_to_cpu(from->sb_ifree);
642 	to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
643 	to->sb_frextents = be64_to_cpu(from->sb_frextents);
644 	to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
645 	to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
646 	to->sb_qflags = be16_to_cpu(from->sb_qflags);
647 	to->sb_flags = from->sb_flags;
648 	to->sb_shared_vn = from->sb_shared_vn;
649 	to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
650 	to->sb_unit = be32_to_cpu(from->sb_unit);
651 	to->sb_width = be32_to_cpu(from->sb_width);
652 	to->sb_dirblklog = from->sb_dirblklog;
653 	to->sb_logsectlog = from->sb_logsectlog;
654 	to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
655 	to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
656 	to->sb_features2 = be32_to_cpu(from->sb_features2);
657 	to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
658 	to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
659 	to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
660 	to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
661 	to->sb_features_log_incompat =
662 				be32_to_cpu(from->sb_features_log_incompat);
663 	/* crc is only used on disk, not in memory; just init to 0 here. */
664 	to->sb_crc = 0;
665 	to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
666 	to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
667 	to->sb_lsn = be64_to_cpu(from->sb_lsn);
668 	/*
669 	 * sb_meta_uuid is only on disk if it differs from sb_uuid and the
670 	 * feature flag is set; if not set we keep it only in memory.
671 	 */
672 	if (xfs_sb_is_v5(to) &&
673 	    (to->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID))
674 		uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
675 	else
676 		uuid_copy(&to->sb_meta_uuid, &from->sb_uuid);
677 	/* Convert on-disk flags to in-memory flags? */
678 	if (convert_xquota)
679 		xfs_sb_quota_from_disk(to);
680 }
681 
682 void
683 xfs_sb_from_disk(
684 	struct xfs_sb	*to,
685 	struct xfs_dsb	*from)
686 {
687 	__xfs_sb_from_disk(to, from, true);
688 }
689 
690 static void
691 xfs_sb_quota_to_disk(
692 	struct xfs_dsb	*to,
693 	struct xfs_sb	*from)
694 {
695 	uint16_t	qflags = from->sb_qflags;
696 
697 	to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
698 
699 	/*
700 	 * The in-memory superblock quota state matches the v5 on-disk format so
701 	 * just write them out and return
702 	 */
703 	if (xfs_sb_is_v5(from)) {
704 		to->sb_qflags = cpu_to_be16(from->sb_qflags);
705 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
706 		to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
707 		return;
708 	}
709 
710 	/*
711 	 * For older superblocks (v4), the in-core version of sb_qflags do not
712 	 * have XFS_OQUOTA_* flags, whereas the on-disk version does.  So,
713 	 * convert incore XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
714 	 */
715 	qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
716 			XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
717 
718 	if (from->sb_qflags &
719 			(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
720 		qflags |= XFS_OQUOTA_ENFD;
721 	if (from->sb_qflags &
722 			(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
723 		qflags |= XFS_OQUOTA_CHKD;
724 	to->sb_qflags = cpu_to_be16(qflags);
725 
726 	/*
727 	 * GQUOTINO and PQUOTINO cannot be used together in versions
728 	 * of superblock that do not have pquotino. from->sb_flags
729 	 * tells us which quota is active and should be copied to
730 	 * disk. If neither are active, we should NULL the inode.
731 	 *
732 	 * In all cases, the separate pquotino must remain 0 because it
733 	 * is beyond the "end" of the valid non-pquotino superblock.
734 	 */
735 	if (from->sb_qflags & XFS_GQUOTA_ACCT)
736 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
737 	else if (from->sb_qflags & XFS_PQUOTA_ACCT)
738 		to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
739 	else {
740 		/*
741 		 * We can't rely on just the fields being logged to tell us
742 		 * that it is safe to write NULLFSINO - we should only do that
743 		 * if quotas are not actually enabled. Hence only write
744 		 * NULLFSINO if both in-core quota inodes are NULL.
745 		 */
746 		if (from->sb_gquotino == NULLFSINO &&
747 		    from->sb_pquotino == NULLFSINO)
748 			to->sb_gquotino = cpu_to_be64(NULLFSINO);
749 	}
750 
751 	to->sb_pquotino = 0;
752 }
753 
754 void
755 xfs_sb_to_disk(
756 	struct xfs_dsb	*to,
757 	struct xfs_sb	*from)
758 {
759 	xfs_sb_quota_to_disk(to, from);
760 
761 	to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
762 	to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
763 	to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
764 	to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
765 	to->sb_rextents = cpu_to_be64(from->sb_rextents);
766 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
767 	to->sb_logstart = cpu_to_be64(from->sb_logstart);
768 	to->sb_rootino = cpu_to_be64(from->sb_rootino);
769 	to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
770 	to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
771 	to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
772 	to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
773 	to->sb_agcount = cpu_to_be32(from->sb_agcount);
774 	to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
775 	to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
776 	to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
777 	to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
778 	to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
779 	to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
780 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
781 	to->sb_blocklog = from->sb_blocklog;
782 	to->sb_sectlog = from->sb_sectlog;
783 	to->sb_inodelog = from->sb_inodelog;
784 	to->sb_inopblog = from->sb_inopblog;
785 	to->sb_agblklog = from->sb_agblklog;
786 	to->sb_rextslog = from->sb_rextslog;
787 	to->sb_inprogress = from->sb_inprogress;
788 	to->sb_imax_pct = from->sb_imax_pct;
789 	to->sb_icount = cpu_to_be64(from->sb_icount);
790 	to->sb_ifree = cpu_to_be64(from->sb_ifree);
791 	to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
792 	to->sb_frextents = cpu_to_be64(from->sb_frextents);
793 
794 	to->sb_flags = from->sb_flags;
795 	to->sb_shared_vn = from->sb_shared_vn;
796 	to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
797 	to->sb_unit = cpu_to_be32(from->sb_unit);
798 	to->sb_width = cpu_to_be32(from->sb_width);
799 	to->sb_dirblklog = from->sb_dirblklog;
800 	to->sb_logsectlog = from->sb_logsectlog;
801 	to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
802 	to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
803 
804 	/*
805 	 * We need to ensure that bad_features2 always matches features2.
806 	 * Hence we enforce that here rather than having to remember to do it
807 	 * everywhere else that updates features2.
808 	 */
809 	from->sb_bad_features2 = from->sb_features2;
810 	to->sb_features2 = cpu_to_be32(from->sb_features2);
811 	to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
812 
813 	if (!xfs_sb_is_v5(from))
814 		return;
815 
816 	to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
817 	to->sb_features_ro_compat =
818 			cpu_to_be32(from->sb_features_ro_compat);
819 	to->sb_features_incompat =
820 			cpu_to_be32(from->sb_features_incompat);
821 	to->sb_features_log_incompat =
822 			cpu_to_be32(from->sb_features_log_incompat);
823 	to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
824 	to->sb_lsn = cpu_to_be64(from->sb_lsn);
825 	if (from->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID)
826 		uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
827 }
828 
829 /*
830  * If the superblock has the CRC feature bit set or the CRC field is non-null,
831  * check that the CRC is valid.  We check the CRC field is non-null because a
832  * single bit error could clear the feature bit and unused parts of the
833  * superblock are supposed to be zero. Hence a non-null crc field indicates that
834  * we've potentially lost a feature bit and we should check it anyway.
835  *
836  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
837  * last field in V4 secondary superblocks.  So for secondary superblocks,
838  * we are more forgiving, and ignore CRC failures if the primary doesn't
839  * indicate that the fs version is V5.
840  */
841 static void
842 xfs_sb_read_verify(
843 	struct xfs_buf		*bp)
844 {
845 	struct xfs_sb		sb;
846 	struct xfs_mount	*mp = bp->b_mount;
847 	struct xfs_dsb		*dsb = bp->b_addr;
848 	int			error;
849 
850 	/*
851 	 * open code the version check to avoid needing to convert the entire
852 	 * superblock from disk order just to check the version number
853 	 */
854 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
855 	    (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
856 						XFS_SB_VERSION_5) ||
857 	     dsb->sb_crc != 0)) {
858 
859 		if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
860 			/* Only fail bad secondaries on a known V5 filesystem */
861 			if (xfs_buf_daddr(bp) == XFS_SB_DADDR ||
862 			    xfs_has_crc(mp)) {
863 				error = -EFSBADCRC;
864 				goto out_error;
865 			}
866 		}
867 	}
868 
869 	/*
870 	 * Check all the superblock fields.  Don't byteswap the xquota flags
871 	 * because _verify_common checks the on-disk values.
872 	 */
873 	__xfs_sb_from_disk(&sb, dsb, false);
874 	error = xfs_validate_sb_common(mp, bp, &sb);
875 	if (error)
876 		goto out_error;
877 	error = xfs_validate_sb_read(mp, &sb);
878 
879 out_error:
880 	if (error == -EFSCORRUPTED || error == -EFSBADCRC)
881 		xfs_verifier_error(bp, error, __this_address);
882 	else if (error)
883 		xfs_buf_ioerror(bp, error);
884 }
885 
886 /*
887  * We may be probed for a filesystem match, so we may not want to emit
888  * messages when the superblock buffer is not actually an XFS superblock.
889  * If we find an XFS superblock, then run a normal, noisy mount because we are
890  * really going to mount it and want to know about errors.
891  */
892 static void
893 xfs_sb_quiet_read_verify(
894 	struct xfs_buf	*bp)
895 {
896 	struct xfs_dsb	*dsb = bp->b_addr;
897 
898 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
899 		/* XFS filesystem, verify noisily! */
900 		xfs_sb_read_verify(bp);
901 		return;
902 	}
903 	/* quietly fail */
904 	xfs_buf_ioerror(bp, -EWRONGFS);
905 }
906 
907 static void
908 xfs_sb_write_verify(
909 	struct xfs_buf		*bp)
910 {
911 	struct xfs_sb		sb;
912 	struct xfs_mount	*mp = bp->b_mount;
913 	struct xfs_buf_log_item	*bip = bp->b_log_item;
914 	struct xfs_dsb		*dsb = bp->b_addr;
915 	int			error;
916 
917 	/*
918 	 * Check all the superblock fields.  Don't byteswap the xquota flags
919 	 * because _verify_common checks the on-disk values.
920 	 */
921 	__xfs_sb_from_disk(&sb, dsb, false);
922 	error = xfs_validate_sb_common(mp, bp, &sb);
923 	if (error)
924 		goto out_error;
925 	error = xfs_validate_sb_write(mp, bp, &sb);
926 	if (error)
927 		goto out_error;
928 
929 	if (!xfs_sb_is_v5(&sb))
930 		return;
931 
932 	if (bip)
933 		dsb->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
934 
935 	xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
936 	return;
937 
938 out_error:
939 	xfs_verifier_error(bp, error, __this_address);
940 }
941 
942 const struct xfs_buf_ops xfs_sb_buf_ops = {
943 	.name = "xfs_sb",
944 	.magic = { cpu_to_be32(XFS_SB_MAGIC), cpu_to_be32(XFS_SB_MAGIC) },
945 	.verify_read = xfs_sb_read_verify,
946 	.verify_write = xfs_sb_write_verify,
947 };
948 
949 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
950 	.name = "xfs_sb_quiet",
951 	.magic = { cpu_to_be32(XFS_SB_MAGIC), cpu_to_be32(XFS_SB_MAGIC) },
952 	.verify_read = xfs_sb_quiet_read_verify,
953 	.verify_write = xfs_sb_write_verify,
954 };
955 
956 /*
957  * xfs_mount_common
958  *
959  * Mount initialization code establishing various mount
960  * fields from the superblock associated with the given
961  * mount structure.
962  *
963  * Inode geometry are calculated in xfs_ialloc_setup_geometry.
964  */
965 void
966 xfs_sb_mount_common(
967 	struct xfs_mount	*mp,
968 	struct xfs_sb		*sbp)
969 {
970 	mp->m_agfrotor = 0;
971 	atomic_set(&mp->m_agirotor, 0);
972 	mp->m_maxagi = mp->m_sb.sb_agcount;
973 	mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
974 	mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
975 	mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
976 	mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
977 	mp->m_blockmask = sbp->sb_blocksize - 1;
978 	mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
979 	mp->m_blockwmask = mp->m_blockwsize - 1;
980 
981 	mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
982 	mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
983 	mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
984 	mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
985 
986 	mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
987 	mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
988 	mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
989 	mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
990 
991 	mp->m_rmap_mxr[0] = xfs_rmapbt_maxrecs(sbp->sb_blocksize, 1);
992 	mp->m_rmap_mxr[1] = xfs_rmapbt_maxrecs(sbp->sb_blocksize, 0);
993 	mp->m_rmap_mnr[0] = mp->m_rmap_mxr[0] / 2;
994 	mp->m_rmap_mnr[1] = mp->m_rmap_mxr[1] / 2;
995 
996 	mp->m_refc_mxr[0] = xfs_refcountbt_maxrecs(sbp->sb_blocksize, true);
997 	mp->m_refc_mxr[1] = xfs_refcountbt_maxrecs(sbp->sb_blocksize, false);
998 	mp->m_refc_mnr[0] = mp->m_refc_mxr[0] / 2;
999 	mp->m_refc_mnr[1] = mp->m_refc_mxr[1] / 2;
1000 
1001 	mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
1002 	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
1003 	mp->m_ag_max_usable = xfs_alloc_ag_max_usable(mp);
1004 }
1005 
1006 /*
1007  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
1008  * into the superblock buffer to be logged.  It does not provide the higher
1009  * level of locking that is needed to protect the in-core superblock from
1010  * concurrent access.
1011  */
1012 void
1013 xfs_log_sb(
1014 	struct xfs_trans	*tp)
1015 {
1016 	struct xfs_mount	*mp = tp->t_mountp;
1017 	struct xfs_buf		*bp = xfs_trans_getsb(tp);
1018 
1019 	/*
1020 	 * Lazy sb counters don't update the in-core superblock so do that now.
1021 	 * If this is at unmount, the counters will be exactly correct, but at
1022 	 * any other time they will only be ballpark correct because of
1023 	 * reservations that have been taken out percpu counters. If we have an
1024 	 * unclean shutdown, this will be corrected by log recovery rebuilding
1025 	 * the counters from the AGF block counts.
1026 	 *
1027 	 * Do not update sb_frextents here because it is not part of the lazy
1028 	 * sb counters, despite having a percpu counter. It is always kept
1029 	 * consistent with the ondisk rtbitmap by xfs_trans_apply_sb_deltas()
1030 	 * and hence we don't need have to update it here.
1031 	 */
1032 	if (xfs_has_lazysbcount(mp)) {
1033 		mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount);
1034 		mp->m_sb.sb_ifree = min_t(uint64_t,
1035 				percpu_counter_sum(&mp->m_ifree),
1036 				mp->m_sb.sb_icount);
1037 		mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
1038 	}
1039 
1040 	xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
1041 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
1042 	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb) - 1);
1043 }
1044 
1045 /*
1046  * xfs_sync_sb
1047  *
1048  * Sync the superblock to disk.
1049  *
1050  * Note that the caller is responsible for checking the frozen state of the
1051  * filesystem. This procedure uses the non-blocking transaction allocator and
1052  * thus will allow modifications to a frozen fs. This is required because this
1053  * code can be called during the process of freezing where use of the high-level
1054  * allocator would deadlock.
1055  */
1056 int
1057 xfs_sync_sb(
1058 	struct xfs_mount	*mp,
1059 	bool			wait)
1060 {
1061 	struct xfs_trans	*tp;
1062 	int			error;
1063 
1064 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0,
1065 			XFS_TRANS_NO_WRITECOUNT, &tp);
1066 	if (error)
1067 		return error;
1068 
1069 	xfs_log_sb(tp);
1070 	if (wait)
1071 		xfs_trans_set_sync(tp);
1072 	return xfs_trans_commit(tp);
1073 }
1074 
1075 /*
1076  * Update all the secondary superblocks to match the new state of the primary.
1077  * Because we are completely overwriting all the existing fields in the
1078  * secondary superblock buffers, there is no need to read them in from disk.
1079  * Just get a new buffer, stamp it and write it.
1080  *
1081  * The sb buffers need to be cached here so that we serialise against other
1082  * operations that access the secondary superblocks, but we don't want to keep
1083  * them in memory once it is written so we mark it as a one-shot buffer.
1084  */
1085 int
1086 xfs_update_secondary_sbs(
1087 	struct xfs_mount	*mp)
1088 {
1089 	struct xfs_perag	*pag;
1090 	xfs_agnumber_t		agno = 1;
1091 	int			saved_error = 0;
1092 	int			error = 0;
1093 	LIST_HEAD		(buffer_list);
1094 
1095 	/* update secondary superblocks. */
1096 	for_each_perag_from(mp, agno, pag) {
1097 		struct xfs_buf		*bp;
1098 
1099 		error = xfs_buf_get(mp->m_ddev_targp,
1100 				 XFS_AG_DADDR(mp, pag->pag_agno, XFS_SB_DADDR),
1101 				 XFS_FSS_TO_BB(mp, 1), &bp);
1102 		/*
1103 		 * If we get an error reading or writing alternate superblocks,
1104 		 * continue.  xfs_repair chooses the "best" superblock based
1105 		 * on most matches; if we break early, we'll leave more
1106 		 * superblocks un-updated than updated, and xfs_repair may
1107 		 * pick them over the properly-updated primary.
1108 		 */
1109 		if (error) {
1110 			xfs_warn(mp,
1111 		"error allocating secondary superblock for ag %d",
1112 				pag->pag_agno);
1113 			if (!saved_error)
1114 				saved_error = error;
1115 			continue;
1116 		}
1117 
1118 		bp->b_ops = &xfs_sb_buf_ops;
1119 		xfs_buf_oneshot(bp);
1120 		xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
1121 		xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
1122 		xfs_buf_delwri_queue(bp, &buffer_list);
1123 		xfs_buf_relse(bp);
1124 
1125 		/* don't hold too many buffers at once */
1126 		if (agno % 16)
1127 			continue;
1128 
1129 		error = xfs_buf_delwri_submit(&buffer_list);
1130 		if (error) {
1131 			xfs_warn(mp,
1132 		"write error %d updating a secondary superblock near ag %d",
1133 				error, pag->pag_agno);
1134 			if (!saved_error)
1135 				saved_error = error;
1136 			continue;
1137 		}
1138 	}
1139 	error = xfs_buf_delwri_submit(&buffer_list);
1140 	if (error) {
1141 		xfs_warn(mp,
1142 		"write error %d updating a secondary superblock near ag %d",
1143 			error, agno);
1144 	}
1145 
1146 	return saved_error ? saved_error : error;
1147 }
1148 
1149 /*
1150  * Same behavior as xfs_sync_sb, except that it is always synchronous and it
1151  * also writes the superblock buffer to disk sector 0 immediately.
1152  */
1153 int
1154 xfs_sync_sb_buf(
1155 	struct xfs_mount	*mp)
1156 {
1157 	struct xfs_trans	*tp;
1158 	struct xfs_buf		*bp;
1159 	int			error;
1160 
1161 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0, 0, &tp);
1162 	if (error)
1163 		return error;
1164 
1165 	bp = xfs_trans_getsb(tp);
1166 	xfs_log_sb(tp);
1167 	xfs_trans_bhold(tp, bp);
1168 	xfs_trans_set_sync(tp);
1169 	error = xfs_trans_commit(tp);
1170 	if (error)
1171 		goto out;
1172 	/*
1173 	 * write out the sb buffer to get the changes to disk
1174 	 */
1175 	error = xfs_bwrite(bp);
1176 out:
1177 	xfs_buf_relse(bp);
1178 	return error;
1179 }
1180 
1181 void
1182 xfs_fs_geometry(
1183 	struct xfs_mount	*mp,
1184 	struct xfs_fsop_geom	*geo,
1185 	int			struct_version)
1186 {
1187 	struct xfs_sb		*sbp = &mp->m_sb;
1188 
1189 	memset(geo, 0, sizeof(struct xfs_fsop_geom));
1190 
1191 	geo->blocksize = sbp->sb_blocksize;
1192 	geo->rtextsize = sbp->sb_rextsize;
1193 	geo->agblocks = sbp->sb_agblocks;
1194 	geo->agcount = sbp->sb_agcount;
1195 	geo->logblocks = sbp->sb_logblocks;
1196 	geo->sectsize = sbp->sb_sectsize;
1197 	geo->inodesize = sbp->sb_inodesize;
1198 	geo->imaxpct = sbp->sb_imax_pct;
1199 	geo->datablocks = sbp->sb_dblocks;
1200 	geo->rtblocks = sbp->sb_rblocks;
1201 	geo->rtextents = sbp->sb_rextents;
1202 	geo->logstart = sbp->sb_logstart;
1203 	BUILD_BUG_ON(sizeof(geo->uuid) != sizeof(sbp->sb_uuid));
1204 	memcpy(geo->uuid, &sbp->sb_uuid, sizeof(sbp->sb_uuid));
1205 
1206 	if (struct_version < 2)
1207 		return;
1208 
1209 	geo->sunit = sbp->sb_unit;
1210 	geo->swidth = sbp->sb_width;
1211 
1212 	if (struct_version < 3)
1213 		return;
1214 
1215 	geo->version = XFS_FSOP_GEOM_VERSION;
1216 	geo->flags = XFS_FSOP_GEOM_FLAGS_NLINK |
1217 		     XFS_FSOP_GEOM_FLAGS_DIRV2 |
1218 		     XFS_FSOP_GEOM_FLAGS_EXTFLG;
1219 	if (xfs_has_attr(mp))
1220 		geo->flags |= XFS_FSOP_GEOM_FLAGS_ATTR;
1221 	if (xfs_has_quota(mp))
1222 		geo->flags |= XFS_FSOP_GEOM_FLAGS_QUOTA;
1223 	if (xfs_has_align(mp))
1224 		geo->flags |= XFS_FSOP_GEOM_FLAGS_IALIGN;
1225 	if (xfs_has_dalign(mp))
1226 		geo->flags |= XFS_FSOP_GEOM_FLAGS_DALIGN;
1227 	if (xfs_has_asciici(mp))
1228 		geo->flags |= XFS_FSOP_GEOM_FLAGS_DIRV2CI;
1229 	if (xfs_has_lazysbcount(mp))
1230 		geo->flags |= XFS_FSOP_GEOM_FLAGS_LAZYSB;
1231 	if (xfs_has_attr2(mp))
1232 		geo->flags |= XFS_FSOP_GEOM_FLAGS_ATTR2;
1233 	if (xfs_has_projid32(mp))
1234 		geo->flags |= XFS_FSOP_GEOM_FLAGS_PROJID32;
1235 	if (xfs_has_crc(mp))
1236 		geo->flags |= XFS_FSOP_GEOM_FLAGS_V5SB;
1237 	if (xfs_has_ftype(mp))
1238 		geo->flags |= XFS_FSOP_GEOM_FLAGS_FTYPE;
1239 	if (xfs_has_finobt(mp))
1240 		geo->flags |= XFS_FSOP_GEOM_FLAGS_FINOBT;
1241 	if (xfs_has_sparseinodes(mp))
1242 		geo->flags |= XFS_FSOP_GEOM_FLAGS_SPINODES;
1243 	if (xfs_has_rmapbt(mp))
1244 		geo->flags |= XFS_FSOP_GEOM_FLAGS_RMAPBT;
1245 	if (xfs_has_reflink(mp))
1246 		geo->flags |= XFS_FSOP_GEOM_FLAGS_REFLINK;
1247 	if (xfs_has_bigtime(mp))
1248 		geo->flags |= XFS_FSOP_GEOM_FLAGS_BIGTIME;
1249 	if (xfs_has_inobtcounts(mp))
1250 		geo->flags |= XFS_FSOP_GEOM_FLAGS_INOBTCNT;
1251 	if (xfs_has_sector(mp)) {
1252 		geo->flags |= XFS_FSOP_GEOM_FLAGS_SECTOR;
1253 		geo->logsectsize = sbp->sb_logsectsize;
1254 	} else {
1255 		geo->logsectsize = BBSIZE;
1256 	}
1257 	if (xfs_has_large_extent_counts(mp))
1258 		geo->flags |= XFS_FSOP_GEOM_FLAGS_NREXT64;
1259 	geo->rtsectsize = sbp->sb_blocksize;
1260 	geo->dirblocksize = xfs_dir2_dirblock_bytes(sbp);
1261 
1262 	if (struct_version < 4)
1263 		return;
1264 
1265 	if (xfs_has_logv2(mp))
1266 		geo->flags |= XFS_FSOP_GEOM_FLAGS_LOGV2;
1267 
1268 	geo->logsunit = sbp->sb_logsunit;
1269 
1270 	if (struct_version < 5)
1271 		return;
1272 
1273 	geo->version = XFS_FSOP_GEOM_VERSION_V5;
1274 }
1275 
1276 /* Read a secondary superblock. */
1277 int
1278 xfs_sb_read_secondary(
1279 	struct xfs_mount	*mp,
1280 	struct xfs_trans	*tp,
1281 	xfs_agnumber_t		agno,
1282 	struct xfs_buf		**bpp)
1283 {
1284 	struct xfs_buf		*bp;
1285 	int			error;
1286 
1287 	ASSERT(agno != 0 && agno != NULLAGNUMBER);
1288 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
1289 			XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
1290 			XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops);
1291 	if (error)
1292 		return error;
1293 	xfs_buf_set_ref(bp, XFS_SSB_REF);
1294 	*bpp = bp;
1295 	return 0;
1296 }
1297 
1298 /* Get an uninitialised secondary superblock buffer. */
1299 int
1300 xfs_sb_get_secondary(
1301 	struct xfs_mount	*mp,
1302 	struct xfs_trans	*tp,
1303 	xfs_agnumber_t		agno,
1304 	struct xfs_buf		**bpp)
1305 {
1306 	struct xfs_buf		*bp;
1307 	int			error;
1308 
1309 	ASSERT(agno != 0 && agno != NULLAGNUMBER);
1310 	error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
1311 			XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
1312 			XFS_FSS_TO_BB(mp, 1), 0, &bp);
1313 	if (error)
1314 		return error;
1315 	bp->b_ops = &xfs_sb_buf_ops;
1316 	xfs_buf_oneshot(bp);
1317 	*bpp = bp;
1318 	return 0;
1319 }
1320 
1321 /*
1322  * sunit, swidth, sectorsize(optional with 0) should be all in bytes,
1323  * so users won't be confused by values in error messages.
1324  */
1325 bool
1326 xfs_validate_stripe_geometry(
1327 	struct xfs_mount	*mp,
1328 	__s64			sunit,
1329 	__s64			swidth,
1330 	int			sectorsize,
1331 	bool			silent)
1332 {
1333 	if (swidth > INT_MAX) {
1334 		if (!silent)
1335 			xfs_notice(mp,
1336 "stripe width (%lld) is too large", swidth);
1337 		return false;
1338 	}
1339 
1340 	if (sunit > swidth) {
1341 		if (!silent)
1342 			xfs_notice(mp,
1343 "stripe unit (%lld) is larger than the stripe width (%lld)", sunit, swidth);
1344 		return false;
1345 	}
1346 
1347 	if (sectorsize && (int)sunit % sectorsize) {
1348 		if (!silent)
1349 			xfs_notice(mp,
1350 "stripe unit (%lld) must be a multiple of the sector size (%d)",
1351 				   sunit, sectorsize);
1352 		return false;
1353 	}
1354 
1355 	if (sunit && !swidth) {
1356 		if (!silent)
1357 			xfs_notice(mp,
1358 "invalid stripe unit (%lld) and stripe width of 0", sunit);
1359 		return false;
1360 	}
1361 
1362 	if (!sunit && swidth) {
1363 		if (!silent)
1364 			xfs_notice(mp,
1365 "invalid stripe width (%lld) and stripe unit of 0", swidth);
1366 		return false;
1367 	}
1368 
1369 	if (sunit && (int)swidth % (int)sunit) {
1370 		if (!silent)
1371 			xfs_notice(mp,
1372 "stripe width (%lld) must be a multiple of the stripe unit (%lld)",
1373 				   swidth, sunit);
1374 		return false;
1375 	}
1376 	return true;
1377 }
1378 
1379 /*
1380  * Compute the maximum level number of the realtime summary file, as defined by
1381  * mkfs.  The historic use of highbit32 on a 64-bit quantity prohibited correct
1382  * use of rt volumes with more than 2^32 extents.
1383  */
1384 uint8_t
1385 xfs_compute_rextslog(
1386 	xfs_rtbxlen_t		rtextents)
1387 {
1388 	if (!rtextents)
1389 		return 0;
1390 	return xfs_highbit64(rtextents);
1391 }
1392