xref: /openbmc/linux/fs/xfs/libxfs/xfs_sb.c (revision 020c5260)
1 /*
2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_bit.h"
25 #include "xfs_sb.h"
26 #include "xfs_mount.h"
27 #include "xfs_defer.h"
28 #include "xfs_inode.h"
29 #include "xfs_ialloc.h"
30 #include "xfs_alloc.h"
31 #include "xfs_error.h"
32 #include "xfs_trace.h"
33 #include "xfs_cksum.h"
34 #include "xfs_trans.h"
35 #include "xfs_buf_item.h"
36 #include "xfs_bmap_btree.h"
37 #include "xfs_alloc_btree.h"
38 #include "xfs_ialloc_btree.h"
39 #include "xfs_log.h"
40 #include "xfs_rmap_btree.h"
41 #include "xfs_bmap.h"
42 #include "xfs_refcount_btree.h"
43 
44 /*
45  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
46  */
47 
48 /*
49  * Reference counting access wrappers to the perag structures.
50  * Because we never free per-ag structures, the only thing we
51  * have to protect against changes is the tree structure itself.
52  */
53 struct xfs_perag *
54 xfs_perag_get(
55 	struct xfs_mount	*mp,
56 	xfs_agnumber_t		agno)
57 {
58 	struct xfs_perag	*pag;
59 	int			ref = 0;
60 
61 	rcu_read_lock();
62 	pag = radix_tree_lookup(&mp->m_perag_tree, agno);
63 	if (pag) {
64 		ASSERT(atomic_read(&pag->pag_ref) >= 0);
65 		ref = atomic_inc_return(&pag->pag_ref);
66 	}
67 	rcu_read_unlock();
68 	trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
69 	return pag;
70 }
71 
72 /*
73  * search from @first to find the next perag with the given tag set.
74  */
75 struct xfs_perag *
76 xfs_perag_get_tag(
77 	struct xfs_mount	*mp,
78 	xfs_agnumber_t		first,
79 	int			tag)
80 {
81 	struct xfs_perag	*pag;
82 	int			found;
83 	int			ref;
84 
85 	rcu_read_lock();
86 	found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
87 					(void **)&pag, first, 1, tag);
88 	if (found <= 0) {
89 		rcu_read_unlock();
90 		return NULL;
91 	}
92 	ref = atomic_inc_return(&pag->pag_ref);
93 	rcu_read_unlock();
94 	trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
95 	return pag;
96 }
97 
98 void
99 xfs_perag_put(
100 	struct xfs_perag	*pag)
101 {
102 	int	ref;
103 
104 	ASSERT(atomic_read(&pag->pag_ref) > 0);
105 	ref = atomic_dec_return(&pag->pag_ref);
106 	trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
107 }
108 
109 /*
110  * Check the validity of the SB found.
111  */
112 STATIC int
113 xfs_mount_validate_sb(
114 	xfs_mount_t	*mp,
115 	xfs_sb_t	*sbp,
116 	bool		check_inprogress,
117 	bool		check_version)
118 {
119 	if (sbp->sb_magicnum != XFS_SB_MAGIC) {
120 		xfs_warn(mp, "bad magic number");
121 		return -EWRONGFS;
122 	}
123 
124 
125 	if (!xfs_sb_good_version(sbp)) {
126 		xfs_warn(mp, "bad version");
127 		return -EWRONGFS;
128 	}
129 
130 	/*
131 	 * Version 5 superblock feature mask validation. Reject combinations the
132 	 * kernel cannot support up front before checking anything else. For
133 	 * write validation, we don't need to check feature masks.
134 	 */
135 	if (check_version && XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) {
136 		if (xfs_sb_has_compat_feature(sbp,
137 					XFS_SB_FEAT_COMPAT_UNKNOWN)) {
138 			xfs_warn(mp,
139 "Superblock has unknown compatible features (0x%x) enabled.",
140 				(sbp->sb_features_compat &
141 						XFS_SB_FEAT_COMPAT_UNKNOWN));
142 			xfs_warn(mp,
143 "Using a more recent kernel is recommended.");
144 		}
145 
146 		if (xfs_sb_has_ro_compat_feature(sbp,
147 					XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
148 			xfs_alert(mp,
149 "Superblock has unknown read-only compatible features (0x%x) enabled.",
150 				(sbp->sb_features_ro_compat &
151 						XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
152 			if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
153 				xfs_warn(mp,
154 "Attempted to mount read-only compatible filesystem read-write.");
155 				xfs_warn(mp,
156 "Filesystem can only be safely mounted read only.");
157 
158 				return -EINVAL;
159 			}
160 		}
161 		if (xfs_sb_has_incompat_feature(sbp,
162 					XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
163 			xfs_warn(mp,
164 "Superblock has unknown incompatible features (0x%x) enabled.",
165 				(sbp->sb_features_incompat &
166 						XFS_SB_FEAT_INCOMPAT_UNKNOWN));
167 			xfs_warn(mp,
168 "Filesystem can not be safely mounted by this kernel.");
169 			return -EINVAL;
170 		}
171 	} else if (xfs_sb_version_hascrc(sbp)) {
172 		/*
173 		 * We can't read verify the sb LSN because the read verifier is
174 		 * called before the log is allocated and processed. We know the
175 		 * log is set up before write verifier (!check_version) calls,
176 		 * so just check it here.
177 		 */
178 		if (!xfs_log_check_lsn(mp, sbp->sb_lsn))
179 			return -EFSCORRUPTED;
180 	}
181 
182 	if (xfs_sb_version_has_pquotino(sbp)) {
183 		if (sbp->sb_qflags & (XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD)) {
184 			xfs_notice(mp,
185 			   "Version 5 of Super block has XFS_OQUOTA bits.");
186 			return -EFSCORRUPTED;
187 		}
188 	} else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
189 				XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
190 			xfs_notice(mp,
191 "Superblock earlier than Version 5 has XFS_[PQ]UOTA_{ENFD|CHKD} bits.");
192 			return -EFSCORRUPTED;
193 	}
194 
195 	/*
196 	 * Full inode chunks must be aligned to inode chunk size when
197 	 * sparse inodes are enabled to support the sparse chunk
198 	 * allocation algorithm and prevent overlapping inode records.
199 	 */
200 	if (xfs_sb_version_hassparseinodes(sbp)) {
201 		uint32_t	align;
202 
203 		align = XFS_INODES_PER_CHUNK * sbp->sb_inodesize
204 				>> sbp->sb_blocklog;
205 		if (sbp->sb_inoalignmt != align) {
206 			xfs_warn(mp,
207 "Inode block alignment (%u) must match chunk size (%u) for sparse inodes.",
208 				 sbp->sb_inoalignmt, align);
209 			return -EINVAL;
210 		}
211 	}
212 
213 	if (unlikely(
214 	    sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
215 		xfs_warn(mp,
216 		"filesystem is marked as having an external log; "
217 		"specify logdev on the mount command line.");
218 		return -EINVAL;
219 	}
220 
221 	if (unlikely(
222 	    sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
223 		xfs_warn(mp,
224 		"filesystem is marked as having an internal log; "
225 		"do not specify logdev on the mount command line.");
226 		return -EINVAL;
227 	}
228 
229 	/*
230 	 * More sanity checking.  Most of these were stolen directly from
231 	 * xfs_repair.
232 	 */
233 	if (unlikely(
234 	    sbp->sb_agcount <= 0					||
235 	    sbp->sb_sectsize < XFS_MIN_SECTORSIZE			||
236 	    sbp->sb_sectsize > XFS_MAX_SECTORSIZE			||
237 	    sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG			||
238 	    sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG			||
239 	    sbp->sb_sectsize != (1 << sbp->sb_sectlog)			||
240 	    sbp->sb_blocksize < XFS_MIN_BLOCKSIZE			||
241 	    sbp->sb_blocksize > XFS_MAX_BLOCKSIZE			||
242 	    sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG			||
243 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
244 	    sbp->sb_blocksize != (1 << sbp->sb_blocklog)		||
245 	    sbp->sb_dirblklog + sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
246 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
247 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
248 	    sbp->sb_inodelog < XFS_DINODE_MIN_LOG			||
249 	    sbp->sb_inodelog > XFS_DINODE_MAX_LOG			||
250 	    sbp->sb_inodesize != (1 << sbp->sb_inodelog)		||
251 	    sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE			||
252 	    sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
253 	    (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)	||
254 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
255 	    (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)	||
256 	    (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)	||
257 	    sbp->sb_dblocks == 0					||
258 	    sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)			||
259 	    sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)			||
260 	    sbp->sb_shared_vn != 0)) {
261 		xfs_notice(mp, "SB sanity check failed");
262 		return -EFSCORRUPTED;
263 	}
264 
265 	if (xfs_sb_version_hascrc(&mp->m_sb) &&
266 	    sbp->sb_blocksize < XFS_MIN_CRC_BLOCKSIZE) {
267 		xfs_notice(mp, "v5 SB sanity check failed");
268 		return -EFSCORRUPTED;
269 	}
270 
271 	/*
272 	 * Until this is fixed only page-sized or smaller data blocks work.
273 	 */
274 	if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
275 		xfs_warn(mp,
276 		"File system with blocksize %d bytes. "
277 		"Only pagesize (%ld) or less will currently work.",
278 				sbp->sb_blocksize, PAGE_SIZE);
279 		return -ENOSYS;
280 	}
281 
282 	/*
283 	 * Currently only very few inode sizes are supported.
284 	 */
285 	switch (sbp->sb_inodesize) {
286 	case 256:
287 	case 512:
288 	case 1024:
289 	case 2048:
290 		break;
291 	default:
292 		xfs_warn(mp, "inode size of %d bytes not supported",
293 				sbp->sb_inodesize);
294 		return -ENOSYS;
295 	}
296 
297 	if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
298 	    xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
299 		xfs_warn(mp,
300 		"file system too large to be mounted on this system.");
301 		return -EFBIG;
302 	}
303 
304 	if (check_inprogress && sbp->sb_inprogress) {
305 		xfs_warn(mp, "Offline file system operation in progress!");
306 		return -EFSCORRUPTED;
307 	}
308 	return 0;
309 }
310 
311 void
312 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
313 {
314 	/*
315 	 * older mkfs doesn't initialize quota inodes to NULLFSINO. This
316 	 * leads to in-core values having two different values for a quota
317 	 * inode to be invalid: 0 and NULLFSINO. Change it to a single value
318 	 * NULLFSINO.
319 	 *
320 	 * Note that this change affect only the in-core values. These
321 	 * values are not written back to disk unless any quota information
322 	 * is written to the disk. Even in that case, sb_pquotino field is
323 	 * not written to disk unless the superblock supports pquotino.
324 	 */
325 	if (sbp->sb_uquotino == 0)
326 		sbp->sb_uquotino = NULLFSINO;
327 	if (sbp->sb_gquotino == 0)
328 		sbp->sb_gquotino = NULLFSINO;
329 	if (sbp->sb_pquotino == 0)
330 		sbp->sb_pquotino = NULLFSINO;
331 
332 	/*
333 	 * We need to do these manipilations only if we are working
334 	 * with an older version of on-disk superblock.
335 	 */
336 	if (xfs_sb_version_has_pquotino(sbp))
337 		return;
338 
339 	if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
340 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
341 					XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
342 	if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
343 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
344 					XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
345 	sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
346 
347 	if (sbp->sb_qflags & XFS_PQUOTA_ACCT &&
348 	    sbp->sb_gquotino != NULLFSINO)  {
349 		/*
350 		 * In older version of superblock, on-disk superblock only
351 		 * has sb_gquotino, and in-core superblock has both sb_gquotino
352 		 * and sb_pquotino. But, only one of them is supported at any
353 		 * point of time. So, if PQUOTA is set in disk superblock,
354 		 * copy over sb_gquotino to sb_pquotino.  The NULLFSINO test
355 		 * above is to make sure we don't do this twice and wipe them
356 		 * both out!
357 		 */
358 		sbp->sb_pquotino = sbp->sb_gquotino;
359 		sbp->sb_gquotino = NULLFSINO;
360 	}
361 }
362 
363 static void
364 __xfs_sb_from_disk(
365 	struct xfs_sb	*to,
366 	xfs_dsb_t	*from,
367 	bool		convert_xquota)
368 {
369 	to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
370 	to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
371 	to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
372 	to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
373 	to->sb_rextents = be64_to_cpu(from->sb_rextents);
374 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
375 	to->sb_logstart = be64_to_cpu(from->sb_logstart);
376 	to->sb_rootino = be64_to_cpu(from->sb_rootino);
377 	to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
378 	to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
379 	to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
380 	to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
381 	to->sb_agcount = be32_to_cpu(from->sb_agcount);
382 	to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
383 	to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
384 	to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
385 	to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
386 	to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
387 	to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
388 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
389 	to->sb_blocklog = from->sb_blocklog;
390 	to->sb_sectlog = from->sb_sectlog;
391 	to->sb_inodelog = from->sb_inodelog;
392 	to->sb_inopblog = from->sb_inopblog;
393 	to->sb_agblklog = from->sb_agblklog;
394 	to->sb_rextslog = from->sb_rextslog;
395 	to->sb_inprogress = from->sb_inprogress;
396 	to->sb_imax_pct = from->sb_imax_pct;
397 	to->sb_icount = be64_to_cpu(from->sb_icount);
398 	to->sb_ifree = be64_to_cpu(from->sb_ifree);
399 	to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
400 	to->sb_frextents = be64_to_cpu(from->sb_frextents);
401 	to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
402 	to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
403 	to->sb_qflags = be16_to_cpu(from->sb_qflags);
404 	to->sb_flags = from->sb_flags;
405 	to->sb_shared_vn = from->sb_shared_vn;
406 	to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
407 	to->sb_unit = be32_to_cpu(from->sb_unit);
408 	to->sb_width = be32_to_cpu(from->sb_width);
409 	to->sb_dirblklog = from->sb_dirblklog;
410 	to->sb_logsectlog = from->sb_logsectlog;
411 	to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
412 	to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
413 	to->sb_features2 = be32_to_cpu(from->sb_features2);
414 	to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
415 	to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
416 	to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
417 	to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
418 	to->sb_features_log_incompat =
419 				be32_to_cpu(from->sb_features_log_incompat);
420 	/* crc is only used on disk, not in memory; just init to 0 here. */
421 	to->sb_crc = 0;
422 	to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
423 	to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
424 	to->sb_lsn = be64_to_cpu(from->sb_lsn);
425 	/*
426 	 * sb_meta_uuid is only on disk if it differs from sb_uuid and the
427 	 * feature flag is set; if not set we keep it only in memory.
428 	 */
429 	if (xfs_sb_version_hasmetauuid(to))
430 		uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
431 	else
432 		uuid_copy(&to->sb_meta_uuid, &from->sb_uuid);
433 	/* Convert on-disk flags to in-memory flags? */
434 	if (convert_xquota)
435 		xfs_sb_quota_from_disk(to);
436 }
437 
438 void
439 xfs_sb_from_disk(
440 	struct xfs_sb	*to,
441 	xfs_dsb_t	*from)
442 {
443 	__xfs_sb_from_disk(to, from, true);
444 }
445 
446 static void
447 xfs_sb_quota_to_disk(
448 	struct xfs_dsb	*to,
449 	struct xfs_sb	*from)
450 {
451 	__uint16_t	qflags = from->sb_qflags;
452 
453 	to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
454 	if (xfs_sb_version_has_pquotino(from)) {
455 		to->sb_qflags = cpu_to_be16(from->sb_qflags);
456 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
457 		to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
458 		return;
459 	}
460 
461 	/*
462 	 * The in-core version of sb_qflags do not have XFS_OQUOTA_*
463 	 * flags, whereas the on-disk version does.  So, convert incore
464 	 * XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
465 	 */
466 	qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
467 			XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
468 
469 	if (from->sb_qflags &
470 			(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
471 		qflags |= XFS_OQUOTA_ENFD;
472 	if (from->sb_qflags &
473 			(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
474 		qflags |= XFS_OQUOTA_CHKD;
475 	to->sb_qflags = cpu_to_be16(qflags);
476 
477 	/*
478 	 * GQUOTINO and PQUOTINO cannot be used together in versions
479 	 * of superblock that do not have pquotino. from->sb_flags
480 	 * tells us which quota is active and should be copied to
481 	 * disk. If neither are active, we should NULL the inode.
482 	 *
483 	 * In all cases, the separate pquotino must remain 0 because it
484 	 * it beyond the "end" of the valid non-pquotino superblock.
485 	 */
486 	if (from->sb_qflags & XFS_GQUOTA_ACCT)
487 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
488 	else if (from->sb_qflags & XFS_PQUOTA_ACCT)
489 		to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
490 	else {
491 		/*
492 		 * We can't rely on just the fields being logged to tell us
493 		 * that it is safe to write NULLFSINO - we should only do that
494 		 * if quotas are not actually enabled. Hence only write
495 		 * NULLFSINO if both in-core quota inodes are NULL.
496 		 */
497 		if (from->sb_gquotino == NULLFSINO &&
498 		    from->sb_pquotino == NULLFSINO)
499 			to->sb_gquotino = cpu_to_be64(NULLFSINO);
500 	}
501 
502 	to->sb_pquotino = 0;
503 }
504 
505 void
506 xfs_sb_to_disk(
507 	struct xfs_dsb	*to,
508 	struct xfs_sb	*from)
509 {
510 	xfs_sb_quota_to_disk(to, from);
511 
512 	to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
513 	to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
514 	to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
515 	to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
516 	to->sb_rextents = cpu_to_be64(from->sb_rextents);
517 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
518 	to->sb_logstart = cpu_to_be64(from->sb_logstart);
519 	to->sb_rootino = cpu_to_be64(from->sb_rootino);
520 	to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
521 	to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
522 	to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
523 	to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
524 	to->sb_agcount = cpu_to_be32(from->sb_agcount);
525 	to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
526 	to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
527 	to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
528 	to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
529 	to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
530 	to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
531 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
532 	to->sb_blocklog = from->sb_blocklog;
533 	to->sb_sectlog = from->sb_sectlog;
534 	to->sb_inodelog = from->sb_inodelog;
535 	to->sb_inopblog = from->sb_inopblog;
536 	to->sb_agblklog = from->sb_agblklog;
537 	to->sb_rextslog = from->sb_rextslog;
538 	to->sb_inprogress = from->sb_inprogress;
539 	to->sb_imax_pct = from->sb_imax_pct;
540 	to->sb_icount = cpu_to_be64(from->sb_icount);
541 	to->sb_ifree = cpu_to_be64(from->sb_ifree);
542 	to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
543 	to->sb_frextents = cpu_to_be64(from->sb_frextents);
544 
545 	to->sb_flags = from->sb_flags;
546 	to->sb_shared_vn = from->sb_shared_vn;
547 	to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
548 	to->sb_unit = cpu_to_be32(from->sb_unit);
549 	to->sb_width = cpu_to_be32(from->sb_width);
550 	to->sb_dirblklog = from->sb_dirblklog;
551 	to->sb_logsectlog = from->sb_logsectlog;
552 	to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
553 	to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
554 
555 	/*
556 	 * We need to ensure that bad_features2 always matches features2.
557 	 * Hence we enforce that here rather than having to remember to do it
558 	 * everywhere else that updates features2.
559 	 */
560 	from->sb_bad_features2 = from->sb_features2;
561 	to->sb_features2 = cpu_to_be32(from->sb_features2);
562 	to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
563 
564 	if (xfs_sb_version_hascrc(from)) {
565 		to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
566 		to->sb_features_ro_compat =
567 				cpu_to_be32(from->sb_features_ro_compat);
568 		to->sb_features_incompat =
569 				cpu_to_be32(from->sb_features_incompat);
570 		to->sb_features_log_incompat =
571 				cpu_to_be32(from->sb_features_log_incompat);
572 		to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
573 		to->sb_lsn = cpu_to_be64(from->sb_lsn);
574 		if (xfs_sb_version_hasmetauuid(from))
575 			uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
576 	}
577 }
578 
579 static int
580 xfs_sb_verify(
581 	struct xfs_buf	*bp,
582 	bool		check_version)
583 {
584 	struct xfs_mount *mp = bp->b_target->bt_mount;
585 	struct xfs_sb	sb;
586 
587 	/*
588 	 * Use call variant which doesn't convert quota flags from disk
589 	 * format, because xfs_mount_validate_sb checks the on-disk flags.
590 	 */
591 	__xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
592 
593 	/*
594 	 * Only check the in progress field for the primary superblock as
595 	 * mkfs.xfs doesn't clear it from secondary superblocks.
596 	 */
597 	return xfs_mount_validate_sb(mp, &sb,
598 				     bp->b_maps[0].bm_bn == XFS_SB_DADDR,
599 				     check_version);
600 }
601 
602 /*
603  * If the superblock has the CRC feature bit set or the CRC field is non-null,
604  * check that the CRC is valid.  We check the CRC field is non-null because a
605  * single bit error could clear the feature bit and unused parts of the
606  * superblock are supposed to be zero. Hence a non-null crc field indicates that
607  * we've potentially lost a feature bit and we should check it anyway.
608  *
609  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
610  * last field in V4 secondary superblocks.  So for secondary superblocks,
611  * we are more forgiving, and ignore CRC failures if the primary doesn't
612  * indicate that the fs version is V5.
613  */
614 static void
615 xfs_sb_read_verify(
616 	struct xfs_buf	*bp)
617 {
618 	struct xfs_mount *mp = bp->b_target->bt_mount;
619 	struct xfs_dsb	*dsb = XFS_BUF_TO_SBP(bp);
620 	int		error;
621 
622 	/*
623 	 * open code the version check to avoid needing to convert the entire
624 	 * superblock from disk order just to check the version number
625 	 */
626 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
627 	    (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
628 						XFS_SB_VERSION_5) ||
629 	     dsb->sb_crc != 0)) {
630 
631 		if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
632 			/* Only fail bad secondaries on a known V5 filesystem */
633 			if (bp->b_bn == XFS_SB_DADDR ||
634 			    xfs_sb_version_hascrc(&mp->m_sb)) {
635 				error = -EFSBADCRC;
636 				goto out_error;
637 			}
638 		}
639 	}
640 	error = xfs_sb_verify(bp, true);
641 
642 out_error:
643 	if (error) {
644 		xfs_buf_ioerror(bp, error);
645 		if (error == -EFSCORRUPTED || error == -EFSBADCRC)
646 			xfs_verifier_error(bp);
647 	}
648 }
649 
650 /*
651  * We may be probed for a filesystem match, so we may not want to emit
652  * messages when the superblock buffer is not actually an XFS superblock.
653  * If we find an XFS superblock, then run a normal, noisy mount because we are
654  * really going to mount it and want to know about errors.
655  */
656 static void
657 xfs_sb_quiet_read_verify(
658 	struct xfs_buf	*bp)
659 {
660 	struct xfs_dsb	*dsb = XFS_BUF_TO_SBP(bp);
661 
662 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
663 		/* XFS filesystem, verify noisily! */
664 		xfs_sb_read_verify(bp);
665 		return;
666 	}
667 	/* quietly fail */
668 	xfs_buf_ioerror(bp, -EWRONGFS);
669 }
670 
671 static void
672 xfs_sb_write_verify(
673 	struct xfs_buf		*bp)
674 {
675 	struct xfs_mount	*mp = bp->b_target->bt_mount;
676 	struct xfs_buf_log_item	*bip = bp->b_fspriv;
677 	int			error;
678 
679 	error = xfs_sb_verify(bp, false);
680 	if (error) {
681 		xfs_buf_ioerror(bp, error);
682 		xfs_verifier_error(bp);
683 		return;
684 	}
685 
686 	if (!xfs_sb_version_hascrc(&mp->m_sb))
687 		return;
688 
689 	if (bip)
690 		XFS_BUF_TO_SBP(bp)->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
691 
692 	xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
693 }
694 
695 const struct xfs_buf_ops xfs_sb_buf_ops = {
696 	.name = "xfs_sb",
697 	.verify_read = xfs_sb_read_verify,
698 	.verify_write = xfs_sb_write_verify,
699 };
700 
701 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
702 	.name = "xfs_sb_quiet",
703 	.verify_read = xfs_sb_quiet_read_verify,
704 	.verify_write = xfs_sb_write_verify,
705 };
706 
707 /*
708  * xfs_mount_common
709  *
710  * Mount initialization code establishing various mount
711  * fields from the superblock associated with the given
712  * mount structure
713  */
714 void
715 xfs_sb_mount_common(
716 	struct xfs_mount *mp,
717 	struct xfs_sb	*sbp)
718 {
719 	mp->m_agfrotor = mp->m_agirotor = 0;
720 	spin_lock_init(&mp->m_agirotor_lock);
721 	mp->m_maxagi = mp->m_sb.sb_agcount;
722 	mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
723 	mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
724 	mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
725 	mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
726 	mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
727 	mp->m_blockmask = sbp->sb_blocksize - 1;
728 	mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
729 	mp->m_blockwmask = mp->m_blockwsize - 1;
730 
731 	mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
732 	mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
733 	mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
734 	mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
735 
736 	mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
737 	mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
738 	mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
739 	mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
740 
741 	mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
742 	mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
743 	mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
744 	mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
745 
746 	mp->m_rmap_mxr[0] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, 1);
747 	mp->m_rmap_mxr[1] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, 0);
748 	mp->m_rmap_mnr[0] = mp->m_rmap_mxr[0] / 2;
749 	mp->m_rmap_mnr[1] = mp->m_rmap_mxr[1] / 2;
750 
751 	mp->m_refc_mxr[0] = xfs_refcountbt_maxrecs(mp, sbp->sb_blocksize,
752 			true);
753 	mp->m_refc_mxr[1] = xfs_refcountbt_maxrecs(mp, sbp->sb_blocksize,
754 			false);
755 	mp->m_refc_mnr[0] = mp->m_refc_mxr[0] / 2;
756 	mp->m_refc_mnr[1] = mp->m_refc_mxr[1] / 2;
757 
758 	mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
759 	mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
760 					sbp->sb_inopblock);
761 	mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
762 
763 	if (sbp->sb_spino_align)
764 		mp->m_ialloc_min_blks = sbp->sb_spino_align;
765 	else
766 		mp->m_ialloc_min_blks = mp->m_ialloc_blks;
767 	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
768 	mp->m_ag_max_usable = xfs_alloc_ag_max_usable(mp);
769 }
770 
771 /*
772  * xfs_initialize_perag_data
773  *
774  * Read in each per-ag structure so we can count up the number of
775  * allocated inodes, free inodes and used filesystem blocks as this
776  * information is no longer persistent in the superblock. Once we have
777  * this information, write it into the in-core superblock structure.
778  */
779 int
780 xfs_initialize_perag_data(
781 	struct xfs_mount *mp,
782 	xfs_agnumber_t	agcount)
783 {
784 	xfs_agnumber_t	index;
785 	xfs_perag_t	*pag;
786 	xfs_sb_t	*sbp = &mp->m_sb;
787 	uint64_t	ifree = 0;
788 	uint64_t	ialloc = 0;
789 	uint64_t	bfree = 0;
790 	uint64_t	bfreelst = 0;
791 	uint64_t	btree = 0;
792 	int		error;
793 
794 	for (index = 0; index < agcount; index++) {
795 		/*
796 		 * read the agf, then the agi. This gets us
797 		 * all the information we need and populates the
798 		 * per-ag structures for us.
799 		 */
800 		error = xfs_alloc_pagf_init(mp, NULL, index, 0);
801 		if (error)
802 			return error;
803 
804 		error = xfs_ialloc_pagi_init(mp, NULL, index);
805 		if (error)
806 			return error;
807 		pag = xfs_perag_get(mp, index);
808 		ifree += pag->pagi_freecount;
809 		ialloc += pag->pagi_count;
810 		bfree += pag->pagf_freeblks;
811 		bfreelst += pag->pagf_flcount;
812 		btree += pag->pagf_btreeblks;
813 		xfs_perag_put(pag);
814 	}
815 
816 	/* Overwrite incore superblock counters with just-read data */
817 	spin_lock(&mp->m_sb_lock);
818 	sbp->sb_ifree = ifree;
819 	sbp->sb_icount = ialloc;
820 	sbp->sb_fdblocks = bfree + bfreelst + btree;
821 	spin_unlock(&mp->m_sb_lock);
822 
823 	xfs_reinit_percpu_counters(mp);
824 
825 	return 0;
826 }
827 
828 /*
829  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
830  * into the superblock buffer to be logged.  It does not provide the higher
831  * level of locking that is needed to protect the in-core superblock from
832  * concurrent access.
833  */
834 void
835 xfs_log_sb(
836 	struct xfs_trans	*tp)
837 {
838 	struct xfs_mount	*mp = tp->t_mountp;
839 	struct xfs_buf		*bp = xfs_trans_getsb(tp, mp, 0);
840 
841 	mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount);
842 	mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree);
843 	mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
844 
845 	xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
846 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
847 	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
848 }
849 
850 /*
851  * xfs_sync_sb
852  *
853  * Sync the superblock to disk.
854  *
855  * Note that the caller is responsible for checking the frozen state of the
856  * filesystem. This procedure uses the non-blocking transaction allocator and
857  * thus will allow modifications to a frozen fs. This is required because this
858  * code can be called during the process of freezing where use of the high-level
859  * allocator would deadlock.
860  */
861 int
862 xfs_sync_sb(
863 	struct xfs_mount	*mp,
864 	bool			wait)
865 {
866 	struct xfs_trans	*tp;
867 	int			error;
868 
869 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0,
870 			XFS_TRANS_NO_WRITECOUNT, &tp);
871 	if (error)
872 		return error;
873 
874 	xfs_log_sb(tp);
875 	if (wait)
876 		xfs_trans_set_sync(tp);
877 	return xfs_trans_commit(tp);
878 }
879