xref: /openbmc/linux/fs/xfs/libxfs/xfs_sb.c (revision 3b27d139)
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_inode.h"
28 #include "xfs_ialloc.h"
29 #include "xfs_alloc.h"
30 #include "xfs_error.h"
31 #include "xfs_trace.h"
32 #include "xfs_cksum.h"
33 #include "xfs_trans.h"
34 #include "xfs_buf_item.h"
35 #include "xfs_bmap_btree.h"
36 #include "xfs_alloc_btree.h"
37 #include "xfs_ialloc_btree.h"
38 
39 /*
40  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
41  */
42 
43 /*
44  * Reference counting access wrappers to the perag structures.
45  * Because we never free per-ag structures, the only thing we
46  * have to protect against changes is the tree structure itself.
47  */
48 struct xfs_perag *
49 xfs_perag_get(
50 	struct xfs_mount	*mp,
51 	xfs_agnumber_t		agno)
52 {
53 	struct xfs_perag	*pag;
54 	int			ref = 0;
55 
56 	rcu_read_lock();
57 	pag = radix_tree_lookup(&mp->m_perag_tree, agno);
58 	if (pag) {
59 		ASSERT(atomic_read(&pag->pag_ref) >= 0);
60 		ref = atomic_inc_return(&pag->pag_ref);
61 	}
62 	rcu_read_unlock();
63 	trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
64 	return pag;
65 }
66 
67 /*
68  * search from @first to find the next perag with the given tag set.
69  */
70 struct xfs_perag *
71 xfs_perag_get_tag(
72 	struct xfs_mount	*mp,
73 	xfs_agnumber_t		first,
74 	int			tag)
75 {
76 	struct xfs_perag	*pag;
77 	int			found;
78 	int			ref;
79 
80 	rcu_read_lock();
81 	found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
82 					(void **)&pag, first, 1, tag);
83 	if (found <= 0) {
84 		rcu_read_unlock();
85 		return NULL;
86 	}
87 	ref = atomic_inc_return(&pag->pag_ref);
88 	rcu_read_unlock();
89 	trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
90 	return pag;
91 }
92 
93 void
94 xfs_perag_put(
95 	struct xfs_perag	*pag)
96 {
97 	int	ref;
98 
99 	ASSERT(atomic_read(&pag->pag_ref) > 0);
100 	ref = atomic_dec_return(&pag->pag_ref);
101 	trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
102 }
103 
104 /*
105  * Check the validity of the SB found.
106  */
107 STATIC int
108 xfs_mount_validate_sb(
109 	xfs_mount_t	*mp,
110 	xfs_sb_t	*sbp,
111 	bool		check_inprogress,
112 	bool		check_version)
113 {
114 	if (sbp->sb_magicnum != XFS_SB_MAGIC) {
115 		xfs_warn(mp, "bad magic number");
116 		return -EWRONGFS;
117 	}
118 
119 
120 	if (!xfs_sb_good_version(sbp)) {
121 		xfs_warn(mp, "bad version");
122 		return -EWRONGFS;
123 	}
124 
125 	/*
126 	 * Version 5 superblock feature mask validation. Reject combinations the
127 	 * kernel cannot support up front before checking anything else. For
128 	 * write validation, we don't need to check feature masks.
129 	 */
130 	if (check_version && XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) {
131 		if (xfs_sb_has_compat_feature(sbp,
132 					XFS_SB_FEAT_COMPAT_UNKNOWN)) {
133 			xfs_warn(mp,
134 "Superblock has unknown compatible features (0x%x) enabled.\n"
135 "Using a more recent kernel is recommended.",
136 				(sbp->sb_features_compat &
137 						XFS_SB_FEAT_COMPAT_UNKNOWN));
138 		}
139 
140 		if (xfs_sb_has_ro_compat_feature(sbp,
141 					XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
142 			xfs_alert(mp,
143 "Superblock has unknown read-only compatible features (0x%x) enabled.",
144 				(sbp->sb_features_ro_compat &
145 						XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
146 			if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
147 				xfs_warn(mp,
148 "Attempted to mount read-only compatible filesystem read-write.\n"
149 "Filesystem can only be safely mounted read only.");
150 				return -EINVAL;
151 			}
152 		}
153 		if (xfs_sb_has_incompat_feature(sbp,
154 					XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
155 			xfs_warn(mp,
156 "Superblock has unknown incompatible features (0x%x) enabled.\n"
157 "Filesystem can not be safely mounted by this kernel.",
158 				(sbp->sb_features_incompat &
159 						XFS_SB_FEAT_INCOMPAT_UNKNOWN));
160 			return -EINVAL;
161 		}
162 	}
163 
164 	if (xfs_sb_version_has_pquotino(sbp)) {
165 		if (sbp->sb_qflags & (XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD)) {
166 			xfs_notice(mp,
167 			   "Version 5 of Super block has XFS_OQUOTA bits.");
168 			return -EFSCORRUPTED;
169 		}
170 	} else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
171 				XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
172 			xfs_notice(mp,
173 "Superblock earlier than Version 5 has XFS_[PQ]UOTA_{ENFD|CHKD} bits.");
174 			return -EFSCORRUPTED;
175 	}
176 
177 	/*
178 	 * Full inode chunks must be aligned to inode chunk size when
179 	 * sparse inodes are enabled to support the sparse chunk
180 	 * allocation algorithm and prevent overlapping inode records.
181 	 */
182 	if (xfs_sb_version_hassparseinodes(sbp)) {
183 		uint32_t	align;
184 
185 		xfs_alert(mp,
186 	"EXPERIMENTAL sparse inode feature enabled. Use at your own risk!");
187 
188 		align = XFS_INODES_PER_CHUNK * sbp->sb_inodesize
189 				>> sbp->sb_blocklog;
190 		if (sbp->sb_inoalignmt != align) {
191 			xfs_warn(mp,
192 "Inode block alignment (%u) must match chunk size (%u) for sparse inodes.",
193 				 sbp->sb_inoalignmt, align);
194 			return -EINVAL;
195 		}
196 	}
197 
198 	if (unlikely(
199 	    sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
200 		xfs_warn(mp,
201 		"filesystem is marked as having an external log; "
202 		"specify logdev on the mount command line.");
203 		return -EINVAL;
204 	}
205 
206 	if (unlikely(
207 	    sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
208 		xfs_warn(mp,
209 		"filesystem is marked as having an internal log; "
210 		"do not specify logdev on the mount command line.");
211 		return -EINVAL;
212 	}
213 
214 	/*
215 	 * More sanity checking.  Most of these were stolen directly from
216 	 * xfs_repair.
217 	 */
218 	if (unlikely(
219 	    sbp->sb_agcount <= 0					||
220 	    sbp->sb_sectsize < XFS_MIN_SECTORSIZE			||
221 	    sbp->sb_sectsize > XFS_MAX_SECTORSIZE			||
222 	    sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG			||
223 	    sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG			||
224 	    sbp->sb_sectsize != (1 << sbp->sb_sectlog)			||
225 	    sbp->sb_blocksize < XFS_MIN_BLOCKSIZE			||
226 	    sbp->sb_blocksize > XFS_MAX_BLOCKSIZE			||
227 	    sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG			||
228 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
229 	    sbp->sb_blocksize != (1 << sbp->sb_blocklog)		||
230 	    sbp->sb_dirblklog > XFS_MAX_BLOCKSIZE_LOG			||
231 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
232 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
233 	    sbp->sb_inodelog < XFS_DINODE_MIN_LOG			||
234 	    sbp->sb_inodelog > XFS_DINODE_MAX_LOG			||
235 	    sbp->sb_inodesize != (1 << sbp->sb_inodelog)		||
236 	    sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE			||
237 	    sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
238 	    (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)	||
239 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
240 	    (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)	||
241 	    (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)	||
242 	    sbp->sb_dblocks == 0					||
243 	    sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)			||
244 	    sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)			||
245 	    sbp->sb_shared_vn != 0)) {
246 		xfs_notice(mp, "SB sanity check failed");
247 		return -EFSCORRUPTED;
248 	}
249 
250 	/*
251 	 * Until this is fixed only page-sized or smaller data blocks work.
252 	 */
253 	if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
254 		xfs_warn(mp,
255 		"File system with blocksize %d bytes. "
256 		"Only pagesize (%ld) or less will currently work.",
257 				sbp->sb_blocksize, PAGE_SIZE);
258 		return -ENOSYS;
259 	}
260 
261 	/*
262 	 * Currently only very few inode sizes are supported.
263 	 */
264 	switch (sbp->sb_inodesize) {
265 	case 256:
266 	case 512:
267 	case 1024:
268 	case 2048:
269 		break;
270 	default:
271 		xfs_warn(mp, "inode size of %d bytes not supported",
272 				sbp->sb_inodesize);
273 		return -ENOSYS;
274 	}
275 
276 	if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
277 	    xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
278 		xfs_warn(mp,
279 		"file system too large to be mounted on this system.");
280 		return -EFBIG;
281 	}
282 
283 	if (check_inprogress && sbp->sb_inprogress) {
284 		xfs_warn(mp, "Offline file system operation in progress!");
285 		return -EFSCORRUPTED;
286 	}
287 	return 0;
288 }
289 
290 void
291 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
292 {
293 	/*
294 	 * older mkfs doesn't initialize quota inodes to NULLFSINO. This
295 	 * leads to in-core values having two different values for a quota
296 	 * inode to be invalid: 0 and NULLFSINO. Change it to a single value
297 	 * NULLFSINO.
298 	 *
299 	 * Note that this change affect only the in-core values. These
300 	 * values are not written back to disk unless any quota information
301 	 * is written to the disk. Even in that case, sb_pquotino field is
302 	 * not written to disk unless the superblock supports pquotino.
303 	 */
304 	if (sbp->sb_uquotino == 0)
305 		sbp->sb_uquotino = NULLFSINO;
306 	if (sbp->sb_gquotino == 0)
307 		sbp->sb_gquotino = NULLFSINO;
308 	if (sbp->sb_pquotino == 0)
309 		sbp->sb_pquotino = NULLFSINO;
310 
311 	/*
312 	 * We need to do these manipilations only if we are working
313 	 * with an older version of on-disk superblock.
314 	 */
315 	if (xfs_sb_version_has_pquotino(sbp))
316 		return;
317 
318 	if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
319 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
320 					XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
321 	if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
322 		sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
323 					XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
324 	sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
325 
326 	if (sbp->sb_qflags & XFS_PQUOTA_ACCT)  {
327 		/*
328 		 * In older version of superblock, on-disk superblock only
329 		 * has sb_gquotino, and in-core superblock has both sb_gquotino
330 		 * and sb_pquotino. But, only one of them is supported at any
331 		 * point of time. So, if PQUOTA is set in disk superblock,
332 		 * copy over sb_gquotino to sb_pquotino.
333 		 */
334 		sbp->sb_pquotino = sbp->sb_gquotino;
335 		sbp->sb_gquotino = NULLFSINO;
336 	}
337 }
338 
339 static void
340 __xfs_sb_from_disk(
341 	struct xfs_sb	*to,
342 	xfs_dsb_t	*from,
343 	bool		convert_xquota)
344 {
345 	to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
346 	to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
347 	to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
348 	to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
349 	to->sb_rextents = be64_to_cpu(from->sb_rextents);
350 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
351 	to->sb_logstart = be64_to_cpu(from->sb_logstart);
352 	to->sb_rootino = be64_to_cpu(from->sb_rootino);
353 	to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
354 	to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
355 	to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
356 	to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
357 	to->sb_agcount = be32_to_cpu(from->sb_agcount);
358 	to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
359 	to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
360 	to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
361 	to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
362 	to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
363 	to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
364 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
365 	to->sb_blocklog = from->sb_blocklog;
366 	to->sb_sectlog = from->sb_sectlog;
367 	to->sb_inodelog = from->sb_inodelog;
368 	to->sb_inopblog = from->sb_inopblog;
369 	to->sb_agblklog = from->sb_agblklog;
370 	to->sb_rextslog = from->sb_rextslog;
371 	to->sb_inprogress = from->sb_inprogress;
372 	to->sb_imax_pct = from->sb_imax_pct;
373 	to->sb_icount = be64_to_cpu(from->sb_icount);
374 	to->sb_ifree = be64_to_cpu(from->sb_ifree);
375 	to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
376 	to->sb_frextents = be64_to_cpu(from->sb_frextents);
377 	to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
378 	to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
379 	to->sb_qflags = be16_to_cpu(from->sb_qflags);
380 	to->sb_flags = from->sb_flags;
381 	to->sb_shared_vn = from->sb_shared_vn;
382 	to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
383 	to->sb_unit = be32_to_cpu(from->sb_unit);
384 	to->sb_width = be32_to_cpu(from->sb_width);
385 	to->sb_dirblklog = from->sb_dirblklog;
386 	to->sb_logsectlog = from->sb_logsectlog;
387 	to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
388 	to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
389 	to->sb_features2 = be32_to_cpu(from->sb_features2);
390 	to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
391 	to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
392 	to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
393 	to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
394 	to->sb_features_log_incompat =
395 				be32_to_cpu(from->sb_features_log_incompat);
396 	/* crc is only used on disk, not in memory; just init to 0 here. */
397 	to->sb_crc = 0;
398 	to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
399 	to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
400 	to->sb_lsn = be64_to_cpu(from->sb_lsn);
401 	/* Convert on-disk flags to in-memory flags? */
402 	if (convert_xquota)
403 		xfs_sb_quota_from_disk(to);
404 }
405 
406 void
407 xfs_sb_from_disk(
408 	struct xfs_sb	*to,
409 	xfs_dsb_t	*from)
410 {
411 	__xfs_sb_from_disk(to, from, true);
412 }
413 
414 static void
415 xfs_sb_quota_to_disk(
416 	struct xfs_dsb	*to,
417 	struct xfs_sb	*from)
418 {
419 	__uint16_t	qflags = from->sb_qflags;
420 
421 	to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
422 	if (xfs_sb_version_has_pquotino(from)) {
423 		to->sb_qflags = cpu_to_be16(from->sb_qflags);
424 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
425 		to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
426 		return;
427 	}
428 
429 	/*
430 	 * The in-core version of sb_qflags do not have XFS_OQUOTA_*
431 	 * flags, whereas the on-disk version does.  So, convert incore
432 	 * XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
433 	 */
434 	qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
435 			XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
436 
437 	if (from->sb_qflags &
438 			(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
439 		qflags |= XFS_OQUOTA_ENFD;
440 	if (from->sb_qflags &
441 			(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
442 		qflags |= XFS_OQUOTA_CHKD;
443 	to->sb_qflags = cpu_to_be16(qflags);
444 
445 	/*
446 	 * GQUOTINO and PQUOTINO cannot be used together in versions
447 	 * of superblock that do not have pquotino. from->sb_flags
448 	 * tells us which quota is active and should be copied to
449 	 * disk. If neither are active, we should NULL the inode.
450 	 *
451 	 * In all cases, the separate pquotino must remain 0 because it
452 	 * it beyond the "end" of the valid non-pquotino superblock.
453 	 */
454 	if (from->sb_qflags & XFS_GQUOTA_ACCT)
455 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
456 	else if (from->sb_qflags & XFS_PQUOTA_ACCT)
457 		to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
458 	else {
459 		/*
460 		 * We can't rely on just the fields being logged to tell us
461 		 * that it is safe to write NULLFSINO - we should only do that
462 		 * if quotas are not actually enabled. Hence only write
463 		 * NULLFSINO if both in-core quota inodes are NULL.
464 		 */
465 		if (from->sb_gquotino == NULLFSINO &&
466 		    from->sb_pquotino == NULLFSINO)
467 			to->sb_gquotino = cpu_to_be64(NULLFSINO);
468 	}
469 
470 	to->sb_pquotino = 0;
471 }
472 
473 void
474 xfs_sb_to_disk(
475 	struct xfs_dsb	*to,
476 	struct xfs_sb	*from)
477 {
478 	xfs_sb_quota_to_disk(to, from);
479 
480 	to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
481 	to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
482 	to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
483 	to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
484 	to->sb_rextents = cpu_to_be64(from->sb_rextents);
485 	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
486 	to->sb_logstart = cpu_to_be64(from->sb_logstart);
487 	to->sb_rootino = cpu_to_be64(from->sb_rootino);
488 	to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
489 	to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
490 	to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
491 	to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
492 	to->sb_agcount = cpu_to_be32(from->sb_agcount);
493 	to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
494 	to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
495 	to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
496 	to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
497 	to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
498 	to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
499 	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
500 	to->sb_blocklog = from->sb_blocklog;
501 	to->sb_sectlog = from->sb_sectlog;
502 	to->sb_inodelog = from->sb_inodelog;
503 	to->sb_inopblog = from->sb_inopblog;
504 	to->sb_agblklog = from->sb_agblklog;
505 	to->sb_rextslog = from->sb_rextslog;
506 	to->sb_inprogress = from->sb_inprogress;
507 	to->sb_imax_pct = from->sb_imax_pct;
508 	to->sb_icount = cpu_to_be64(from->sb_icount);
509 	to->sb_ifree = cpu_to_be64(from->sb_ifree);
510 	to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
511 	to->sb_frextents = cpu_to_be64(from->sb_frextents);
512 
513 	to->sb_flags = from->sb_flags;
514 	to->sb_shared_vn = from->sb_shared_vn;
515 	to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
516 	to->sb_unit = cpu_to_be32(from->sb_unit);
517 	to->sb_width = cpu_to_be32(from->sb_width);
518 	to->sb_dirblklog = from->sb_dirblklog;
519 	to->sb_logsectlog = from->sb_logsectlog;
520 	to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
521 	to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
522 
523 	/*
524 	 * We need to ensure that bad_features2 always matches features2.
525 	 * Hence we enforce that here rather than having to remember to do it
526 	 * everywhere else that updates features2.
527 	 */
528 	from->sb_bad_features2 = from->sb_features2;
529 	to->sb_features2 = cpu_to_be32(from->sb_features2);
530 	to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
531 
532 	if (xfs_sb_version_hascrc(from)) {
533 		to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
534 		to->sb_features_ro_compat =
535 				cpu_to_be32(from->sb_features_ro_compat);
536 		to->sb_features_incompat =
537 				cpu_to_be32(from->sb_features_incompat);
538 		to->sb_features_log_incompat =
539 				cpu_to_be32(from->sb_features_log_incompat);
540 		to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
541 		to->sb_lsn = cpu_to_be64(from->sb_lsn);
542 	}
543 }
544 
545 static int
546 xfs_sb_verify(
547 	struct xfs_buf	*bp,
548 	bool		check_version)
549 {
550 	struct xfs_mount *mp = bp->b_target->bt_mount;
551 	struct xfs_sb	sb;
552 
553 	/*
554 	 * Use call variant which doesn't convert quota flags from disk
555 	 * format, because xfs_mount_validate_sb checks the on-disk flags.
556 	 */
557 	__xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
558 
559 	/*
560 	 * Only check the in progress field for the primary superblock as
561 	 * mkfs.xfs doesn't clear it from secondary superblocks.
562 	 */
563 	return xfs_mount_validate_sb(mp, &sb, bp->b_bn == XFS_SB_DADDR,
564 				     check_version);
565 }
566 
567 /*
568  * If the superblock has the CRC feature bit set or the CRC field is non-null,
569  * check that the CRC is valid.  We check the CRC field is non-null because a
570  * single bit error could clear the feature bit and unused parts of the
571  * superblock are supposed to be zero. Hence a non-null crc field indicates that
572  * we've potentially lost a feature bit and we should check it anyway.
573  *
574  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
575  * last field in V4 secondary superblocks.  So for secondary superblocks,
576  * we are more forgiving, and ignore CRC failures if the primary doesn't
577  * indicate that the fs version is V5.
578  */
579 static void
580 xfs_sb_read_verify(
581 	struct xfs_buf	*bp)
582 {
583 	struct xfs_mount *mp = bp->b_target->bt_mount;
584 	struct xfs_dsb	*dsb = XFS_BUF_TO_SBP(bp);
585 	int		error;
586 
587 	/*
588 	 * open code the version check to avoid needing to convert the entire
589 	 * superblock from disk order just to check the version number
590 	 */
591 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
592 	    (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
593 						XFS_SB_VERSION_5) ||
594 	     dsb->sb_crc != 0)) {
595 
596 		if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
597 			/* Only fail bad secondaries on a known V5 filesystem */
598 			if (bp->b_bn == XFS_SB_DADDR ||
599 			    xfs_sb_version_hascrc(&mp->m_sb)) {
600 				error = -EFSBADCRC;
601 				goto out_error;
602 			}
603 		}
604 	}
605 	error = xfs_sb_verify(bp, true);
606 
607 out_error:
608 	if (error) {
609 		xfs_buf_ioerror(bp, error);
610 		if (error == -EFSCORRUPTED || error == -EFSBADCRC)
611 			xfs_verifier_error(bp);
612 	}
613 }
614 
615 /*
616  * We may be probed for a filesystem match, so we may not want to emit
617  * messages when the superblock buffer is not actually an XFS superblock.
618  * If we find an XFS superblock, then run a normal, noisy mount because we are
619  * really going to mount it and want to know about errors.
620  */
621 static void
622 xfs_sb_quiet_read_verify(
623 	struct xfs_buf	*bp)
624 {
625 	struct xfs_dsb	*dsb = XFS_BUF_TO_SBP(bp);
626 
627 	if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
628 		/* XFS filesystem, verify noisily! */
629 		xfs_sb_read_verify(bp);
630 		return;
631 	}
632 	/* quietly fail */
633 	xfs_buf_ioerror(bp, -EWRONGFS);
634 }
635 
636 static void
637 xfs_sb_write_verify(
638 	struct xfs_buf		*bp)
639 {
640 	struct xfs_mount	*mp = bp->b_target->bt_mount;
641 	struct xfs_buf_log_item	*bip = bp->b_fspriv;
642 	int			error;
643 
644 	error = xfs_sb_verify(bp, false);
645 	if (error) {
646 		xfs_buf_ioerror(bp, error);
647 		xfs_verifier_error(bp);
648 		return;
649 	}
650 
651 	if (!xfs_sb_version_hascrc(&mp->m_sb))
652 		return;
653 
654 	if (bip)
655 		XFS_BUF_TO_SBP(bp)->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
656 
657 	xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
658 }
659 
660 const struct xfs_buf_ops xfs_sb_buf_ops = {
661 	.verify_read = xfs_sb_read_verify,
662 	.verify_write = xfs_sb_write_verify,
663 };
664 
665 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
666 	.verify_read = xfs_sb_quiet_read_verify,
667 	.verify_write = xfs_sb_write_verify,
668 };
669 
670 /*
671  * xfs_mount_common
672  *
673  * Mount initialization code establishing various mount
674  * fields from the superblock associated with the given
675  * mount structure
676  */
677 void
678 xfs_sb_mount_common(
679 	struct xfs_mount *mp,
680 	struct xfs_sb	*sbp)
681 {
682 	mp->m_agfrotor = mp->m_agirotor = 0;
683 	spin_lock_init(&mp->m_agirotor_lock);
684 	mp->m_maxagi = mp->m_sb.sb_agcount;
685 	mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
686 	mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
687 	mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
688 	mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
689 	mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
690 	mp->m_blockmask = sbp->sb_blocksize - 1;
691 	mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
692 	mp->m_blockwmask = mp->m_blockwsize - 1;
693 
694 	mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
695 	mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
696 	mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
697 	mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
698 
699 	mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
700 	mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
701 	mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
702 	mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
703 
704 	mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
705 	mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
706 	mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
707 	mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
708 
709 	mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
710 	mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
711 					sbp->sb_inopblock);
712 	mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
713 
714 	if (sbp->sb_spino_align)
715 		mp->m_ialloc_min_blks = sbp->sb_spino_align;
716 	else
717 		mp->m_ialloc_min_blks = mp->m_ialloc_blks;
718 }
719 
720 /*
721  * xfs_initialize_perag_data
722  *
723  * Read in each per-ag structure so we can count up the number of
724  * allocated inodes, free inodes and used filesystem blocks as this
725  * information is no longer persistent in the superblock. Once we have
726  * this information, write it into the in-core superblock structure.
727  */
728 int
729 xfs_initialize_perag_data(
730 	struct xfs_mount *mp,
731 	xfs_agnumber_t	agcount)
732 {
733 	xfs_agnumber_t	index;
734 	xfs_perag_t	*pag;
735 	xfs_sb_t	*sbp = &mp->m_sb;
736 	uint64_t	ifree = 0;
737 	uint64_t	ialloc = 0;
738 	uint64_t	bfree = 0;
739 	uint64_t	bfreelst = 0;
740 	uint64_t	btree = 0;
741 	int		error;
742 
743 	for (index = 0; index < agcount; index++) {
744 		/*
745 		 * read the agf, then the agi. This gets us
746 		 * all the information we need and populates the
747 		 * per-ag structures for us.
748 		 */
749 		error = xfs_alloc_pagf_init(mp, NULL, index, 0);
750 		if (error)
751 			return error;
752 
753 		error = xfs_ialloc_pagi_init(mp, NULL, index);
754 		if (error)
755 			return error;
756 		pag = xfs_perag_get(mp, index);
757 		ifree += pag->pagi_freecount;
758 		ialloc += pag->pagi_count;
759 		bfree += pag->pagf_freeblks;
760 		bfreelst += pag->pagf_flcount;
761 		btree += pag->pagf_btreeblks;
762 		xfs_perag_put(pag);
763 	}
764 
765 	/* Overwrite incore superblock counters with just-read data */
766 	spin_lock(&mp->m_sb_lock);
767 	sbp->sb_ifree = ifree;
768 	sbp->sb_icount = ialloc;
769 	sbp->sb_fdblocks = bfree + bfreelst + btree;
770 	spin_unlock(&mp->m_sb_lock);
771 
772 	xfs_reinit_percpu_counters(mp);
773 
774 	return 0;
775 }
776 
777 /*
778  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
779  * into the superblock buffer to be logged.  It does not provide the higher
780  * level of locking that is needed to protect the in-core superblock from
781  * concurrent access.
782  */
783 void
784 xfs_log_sb(
785 	struct xfs_trans	*tp)
786 {
787 	struct xfs_mount	*mp = tp->t_mountp;
788 	struct xfs_buf		*bp = xfs_trans_getsb(tp, mp, 0);
789 
790 	mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount);
791 	mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree);
792 	mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
793 
794 	xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
795 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
796 	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
797 }
798 
799 /*
800  * xfs_sync_sb
801  *
802  * Sync the superblock to disk.
803  *
804  * Note that the caller is responsible for checking the frozen state of the
805  * filesystem. This procedure uses the non-blocking transaction allocator and
806  * thus will allow modifications to a frozen fs. This is required because this
807  * code can be called during the process of freezing where use of the high-level
808  * allocator would deadlock.
809  */
810 int
811 xfs_sync_sb(
812 	struct xfs_mount	*mp,
813 	bool			wait)
814 {
815 	struct xfs_trans	*tp;
816 	int			error;
817 
818 	tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_CHANGE, KM_SLEEP);
819 	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
820 	if (error) {
821 		xfs_trans_cancel(tp);
822 		return error;
823 	}
824 
825 	xfs_log_sb(tp);
826 	if (wait)
827 		xfs_trans_set_sync(tp);
828 	return xfs_trans_commit(tp);
829 }
830