xref: /openbmc/linux/fs/xfs/xfs_mount.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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_types.h"
21 #include "xfs_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_dir.h"
28 #include "xfs_dir2.h"
29 #include "xfs_dmapi.h"
30 #include "xfs_mount.h"
31 #include "xfs_bmap_btree.h"
32 #include "xfs_alloc_btree.h"
33 #include "xfs_ialloc_btree.h"
34 #include "xfs_dir_sf.h"
35 #include "xfs_dir2_sf.h"
36 #include "xfs_attr_sf.h"
37 #include "xfs_dinode.h"
38 #include "xfs_inode.h"
39 #include "xfs_btree.h"
40 #include "xfs_ialloc.h"
41 #include "xfs_alloc.h"
42 #include "xfs_rtalloc.h"
43 #include "xfs_bmap.h"
44 #include "xfs_error.h"
45 #include "xfs_rw.h"
46 #include "xfs_quota.h"
47 #include "xfs_fsops.h"
48 
49 STATIC void	xfs_mount_log_sbunit(xfs_mount_t *, __int64_t);
50 STATIC int	xfs_uuid_mount(xfs_mount_t *);
51 STATIC void	xfs_uuid_unmount(xfs_mount_t *mp);
52 STATIC void	xfs_unmountfs_wait(xfs_mount_t *);
53 
54 static struct {
55     short offset;
56     short type;     /* 0 = integer
57 		* 1 = binary / string (no translation)
58 		*/
59 } xfs_sb_info[] = {
60     { offsetof(xfs_sb_t, sb_magicnum),   0 },
61     { offsetof(xfs_sb_t, sb_blocksize),  0 },
62     { offsetof(xfs_sb_t, sb_dblocks),    0 },
63     { offsetof(xfs_sb_t, sb_rblocks),    0 },
64     { offsetof(xfs_sb_t, sb_rextents),   0 },
65     { offsetof(xfs_sb_t, sb_uuid),       1 },
66     { offsetof(xfs_sb_t, sb_logstart),   0 },
67     { offsetof(xfs_sb_t, sb_rootino),    0 },
68     { offsetof(xfs_sb_t, sb_rbmino),     0 },
69     { offsetof(xfs_sb_t, sb_rsumino),    0 },
70     { offsetof(xfs_sb_t, sb_rextsize),   0 },
71     { offsetof(xfs_sb_t, sb_agblocks),   0 },
72     { offsetof(xfs_sb_t, sb_agcount),    0 },
73     { offsetof(xfs_sb_t, sb_rbmblocks),  0 },
74     { offsetof(xfs_sb_t, sb_logblocks),  0 },
75     { offsetof(xfs_sb_t, sb_versionnum), 0 },
76     { offsetof(xfs_sb_t, sb_sectsize),   0 },
77     { offsetof(xfs_sb_t, sb_inodesize),  0 },
78     { offsetof(xfs_sb_t, sb_inopblock),  0 },
79     { offsetof(xfs_sb_t, sb_fname[0]),   1 },
80     { offsetof(xfs_sb_t, sb_blocklog),   0 },
81     { offsetof(xfs_sb_t, sb_sectlog),    0 },
82     { offsetof(xfs_sb_t, sb_inodelog),   0 },
83     { offsetof(xfs_sb_t, sb_inopblog),   0 },
84     { offsetof(xfs_sb_t, sb_agblklog),   0 },
85     { offsetof(xfs_sb_t, sb_rextslog),   0 },
86     { offsetof(xfs_sb_t, sb_inprogress), 0 },
87     { offsetof(xfs_sb_t, sb_imax_pct),   0 },
88     { offsetof(xfs_sb_t, sb_icount),     0 },
89     { offsetof(xfs_sb_t, sb_ifree),      0 },
90     { offsetof(xfs_sb_t, sb_fdblocks),   0 },
91     { offsetof(xfs_sb_t, sb_frextents),  0 },
92     { offsetof(xfs_sb_t, sb_uquotino),   0 },
93     { offsetof(xfs_sb_t, sb_gquotino),   0 },
94     { offsetof(xfs_sb_t, sb_qflags),     0 },
95     { offsetof(xfs_sb_t, sb_flags),      0 },
96     { offsetof(xfs_sb_t, sb_shared_vn),  0 },
97     { offsetof(xfs_sb_t, sb_inoalignmt), 0 },
98     { offsetof(xfs_sb_t, sb_unit),	 0 },
99     { offsetof(xfs_sb_t, sb_width),	 0 },
100     { offsetof(xfs_sb_t, sb_dirblklog),	 0 },
101     { offsetof(xfs_sb_t, sb_logsectlog), 0 },
102     { offsetof(xfs_sb_t, sb_logsectsize),0 },
103     { offsetof(xfs_sb_t, sb_logsunit),	 0 },
104     { offsetof(xfs_sb_t, sb_features2),	 0 },
105     { sizeof(xfs_sb_t),			 0 }
106 };
107 
108 /*
109  * Return a pointer to an initialized xfs_mount structure.
110  */
111 xfs_mount_t *
112 xfs_mount_init(void)
113 {
114 	xfs_mount_t *mp;
115 
116 	mp = kmem_zalloc(sizeof(*mp), KM_SLEEP);
117 
118 	AIL_LOCKINIT(&mp->m_ail_lock, "xfs_ail");
119 	spinlock_init(&mp->m_sb_lock, "xfs_sb");
120 	mutex_init(&mp->m_ilock, MUTEX_DEFAULT, "xfs_ilock");
121 	initnsema(&mp->m_growlock, 1, "xfs_grow");
122 	/*
123 	 * Initialize the AIL.
124 	 */
125 	xfs_trans_ail_init(mp);
126 
127 	atomic_set(&mp->m_active_trans, 0);
128 
129 	return mp;
130 }
131 
132 /*
133  * Free up the resources associated with a mount structure.  Assume that
134  * the structure was initially zeroed, so we can tell which fields got
135  * initialized.
136  */
137 void
138 xfs_mount_free(
139 	xfs_mount_t *mp,
140 	int	    remove_bhv)
141 {
142 	if (mp->m_ihash)
143 		xfs_ihash_free(mp);
144 	if (mp->m_chash)
145 		xfs_chash_free(mp);
146 
147 	if (mp->m_perag) {
148 		int	agno;
149 
150 		for (agno = 0; agno < mp->m_maxagi; agno++)
151 			if (mp->m_perag[agno].pagb_list)
152 				kmem_free(mp->m_perag[agno].pagb_list,
153 						sizeof(xfs_perag_busy_t) *
154 							XFS_PAGB_NUM_SLOTS);
155 		kmem_free(mp->m_perag,
156 			  sizeof(xfs_perag_t) * mp->m_sb.sb_agcount);
157 	}
158 
159 	AIL_LOCK_DESTROY(&mp->m_ail_lock);
160 	spinlock_destroy(&mp->m_sb_lock);
161 	mutex_destroy(&mp->m_ilock);
162 	freesema(&mp->m_growlock);
163 	if (mp->m_quotainfo)
164 		XFS_QM_DONE(mp);
165 
166 	if (mp->m_fsname != NULL)
167 		kmem_free(mp->m_fsname, mp->m_fsname_len);
168 	if (mp->m_rtname != NULL)
169 		kmem_free(mp->m_rtname, strlen(mp->m_rtname) + 1);
170 	if (mp->m_logname != NULL)
171 		kmem_free(mp->m_logname, strlen(mp->m_logname) + 1);
172 
173 	if (remove_bhv) {
174 		struct vfs	*vfsp = XFS_MTOVFS(mp);
175 
176 		bhv_remove_all_vfsops(vfsp, 0);
177 		VFS_REMOVEBHV(vfsp, &mp->m_bhv);
178 	}
179 
180 	kmem_free(mp, sizeof(xfs_mount_t));
181 }
182 
183 
184 /*
185  * Check the validity of the SB found.
186  */
187 STATIC int
188 xfs_mount_validate_sb(
189 	xfs_mount_t	*mp,
190 	xfs_sb_t	*sbp)
191 {
192 	/*
193 	 * If the log device and data device have the
194 	 * same device number, the log is internal.
195 	 * Consequently, the sb_logstart should be non-zero.  If
196 	 * we have a zero sb_logstart in this case, we may be trying to mount
197 	 * a volume filesystem in a non-volume manner.
198 	 */
199 	if (sbp->sb_magicnum != XFS_SB_MAGIC) {
200 		cmn_err(CE_WARN, "XFS: bad magic number");
201 		return XFS_ERROR(EWRONGFS);
202 	}
203 
204 	if (!XFS_SB_GOOD_VERSION(sbp)) {
205 		cmn_err(CE_WARN, "XFS: bad version");
206 		return XFS_ERROR(EWRONGFS);
207 	}
208 
209 	if (unlikely(
210 	    sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
211 		cmn_err(CE_WARN,
212 	"XFS: filesystem is marked as having an external log; "
213 	"specify logdev on the\nmount command line.");
214 		XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(1)",
215 				     XFS_ERRLEVEL_HIGH, mp, sbp);
216 		return XFS_ERROR(EFSCORRUPTED);
217 	}
218 
219 	if (unlikely(
220 	    sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
221 		cmn_err(CE_WARN,
222 	"XFS: filesystem is marked as having an internal log; "
223 	"don't specify logdev on\nthe mount command line.");
224 		XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(2)",
225 				     XFS_ERRLEVEL_HIGH, mp, sbp);
226 		return XFS_ERROR(EFSCORRUPTED);
227 	}
228 
229 	/*
230 	 * More sanity checking. 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_blocksize < XFS_MIN_BLOCKSIZE			||
240 	    sbp->sb_blocksize > XFS_MAX_BLOCKSIZE			||
241 	    sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG			||
242 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
243 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
244 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
245 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
246 	    (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)	||
247 	    sbp->sb_imax_pct > 100)) {
248 		cmn_err(CE_WARN, "XFS: SB sanity check 1 failed");
249 		XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(3)",
250 				     XFS_ERRLEVEL_LOW, mp, sbp);
251 		return XFS_ERROR(EFSCORRUPTED);
252 	}
253 
254 	/*
255 	 * Sanity check AG count, size fields against data size field
256 	 */
257 	if (unlikely(
258 	    sbp->sb_dblocks == 0 ||
259 	    sbp->sb_dblocks >
260 	     (xfs_drfsbno_t)sbp->sb_agcount * sbp->sb_agblocks ||
261 	    sbp->sb_dblocks < (xfs_drfsbno_t)(sbp->sb_agcount - 1) *
262 			      sbp->sb_agblocks + XFS_MIN_AG_BLOCKS)) {
263 		cmn_err(CE_WARN, "XFS: SB sanity check 2 failed");
264 		XFS_ERROR_REPORT("xfs_mount_validate_sb(4)",
265 				 XFS_ERRLEVEL_LOW, mp);
266 		return XFS_ERROR(EFSCORRUPTED);
267 	}
268 
269 	ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
270 	ASSERT(sbp->sb_blocklog >= BBSHIFT);
271 
272 #if XFS_BIG_BLKNOS     /* Limited by ULONG_MAX of page cache index */
273 	if (unlikely(
274 	    (sbp->sb_dblocks >> (PAGE_SHIFT - sbp->sb_blocklog)) > ULONG_MAX ||
275 	    (sbp->sb_rblocks >> (PAGE_SHIFT - sbp->sb_blocklog)) > ULONG_MAX)) {
276 #else                  /* Limited by UINT_MAX of sectors */
277 	if (unlikely(
278 	    (sbp->sb_dblocks << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX ||
279 	    (sbp->sb_rblocks << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX)) {
280 #endif
281 		cmn_err(CE_WARN,
282 	"XFS: File system is too large to be mounted on this system.");
283 		return XFS_ERROR(E2BIG);
284 	}
285 
286 	if (unlikely(sbp->sb_inprogress)) {
287 		cmn_err(CE_WARN, "XFS: file system busy");
288 		XFS_ERROR_REPORT("xfs_mount_validate_sb(5)",
289 				 XFS_ERRLEVEL_LOW, mp);
290 		return XFS_ERROR(EFSCORRUPTED);
291 	}
292 
293 	/*
294 	 * Version 1 directory format has never worked on Linux.
295 	 */
296 	if (unlikely(!XFS_SB_VERSION_HASDIRV2(sbp))) {
297 		cmn_err(CE_WARN,
298 	"XFS: Attempted to mount file system using version 1 directory format");
299 		return XFS_ERROR(ENOSYS);
300 	}
301 
302 	/*
303 	 * Until this is fixed only page-sized or smaller data blocks work.
304 	 */
305 	if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
306 		cmn_err(CE_WARN,
307 		"XFS: Attempted to mount file system with blocksize %d bytes",
308 			sbp->sb_blocksize);
309 		cmn_err(CE_WARN,
310 		"XFS: Only page-sized (%ld) or less blocksizes currently work.",
311 			PAGE_SIZE);
312 		return XFS_ERROR(ENOSYS);
313 	}
314 
315 	return 0;
316 }
317 
318 xfs_agnumber_t
319 xfs_initialize_perag(
320 	struct vfs	*vfs,
321 	xfs_mount_t	*mp,
322 	xfs_agnumber_t	agcount)
323 {
324 	xfs_agnumber_t	index, max_metadata;
325 	xfs_perag_t	*pag;
326 	xfs_agino_t	agino;
327 	xfs_ino_t	ino;
328 	xfs_sb_t	*sbp = &mp->m_sb;
329 	xfs_ino_t	max_inum = XFS_MAXINUMBER_32;
330 
331 	/* Check to see if the filesystem can overflow 32 bit inodes */
332 	agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
333 	ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
334 
335 	/* Clear the mount flag if no inode can overflow 32 bits
336 	 * on this filesystem, or if specifically requested..
337 	 */
338 	if ((vfs->vfs_flag & VFS_32BITINODES) && ino > max_inum) {
339 		mp->m_flags |= XFS_MOUNT_32BITINODES;
340 	} else {
341 		mp->m_flags &= ~XFS_MOUNT_32BITINODES;
342 	}
343 
344 	/* If we can overflow then setup the ag headers accordingly */
345 	if (mp->m_flags & XFS_MOUNT_32BITINODES) {
346 		/* Calculate how much should be reserved for inodes to
347 		 * meet the max inode percentage.
348 		 */
349 		if (mp->m_maxicount) {
350 			__uint64_t	icount;
351 
352 			icount = sbp->sb_dblocks * sbp->sb_imax_pct;
353 			do_div(icount, 100);
354 			icount += sbp->sb_agblocks - 1;
355 			do_div(icount, sbp->sb_agblocks);
356 			max_metadata = icount;
357 		} else {
358 			max_metadata = agcount;
359 		}
360 		for (index = 0; index < agcount; index++) {
361 			ino = XFS_AGINO_TO_INO(mp, index, agino);
362 			if (ino > max_inum) {
363 				index++;
364 				break;
365 			}
366 
367 			/* This ag is prefered for inodes */
368 			pag = &mp->m_perag[index];
369 			pag->pagi_inodeok = 1;
370 			if (index < max_metadata)
371 				pag->pagf_metadata = 1;
372 		}
373 	} else {
374 		/* Setup default behavior for smaller filesystems */
375 		for (index = 0; index < agcount; index++) {
376 			pag = &mp->m_perag[index];
377 			pag->pagi_inodeok = 1;
378 		}
379 	}
380 	return index;
381 }
382 
383 /*
384  * xfs_xlatesb
385  *
386  *     data       - on disk version of sb
387  *     sb         - a superblock
388  *     dir        - conversion direction: <0 - convert sb to buf
389  *                                        >0 - convert buf to sb
390  *     fields     - which fields to copy (bitmask)
391  */
392 void
393 xfs_xlatesb(
394 	void		*data,
395 	xfs_sb_t	*sb,
396 	int		dir,
397 	__int64_t	fields)
398 {
399 	xfs_caddr_t	buf_ptr;
400 	xfs_caddr_t	mem_ptr;
401 	xfs_sb_field_t	f;
402 	int		first;
403 	int		size;
404 
405 	ASSERT(dir);
406 	ASSERT(fields);
407 
408 	if (!fields)
409 		return;
410 
411 	buf_ptr = (xfs_caddr_t)data;
412 	mem_ptr = (xfs_caddr_t)sb;
413 
414 	while (fields) {
415 		f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
416 		first = xfs_sb_info[f].offset;
417 		size = xfs_sb_info[f + 1].offset - first;
418 
419 		ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
420 
421 		if (size == 1 || xfs_sb_info[f].type == 1) {
422 			if (dir > 0) {
423 				memcpy(mem_ptr + first, buf_ptr + first, size);
424 			} else {
425 				memcpy(buf_ptr + first, mem_ptr + first, size);
426 			}
427 		} else {
428 			switch (size) {
429 			case 2:
430 				INT_XLATE(*(__uint16_t*)(buf_ptr+first),
431 					  *(__uint16_t*)(mem_ptr+first),
432 					  dir, ARCH_CONVERT);
433 				break;
434 			case 4:
435 				INT_XLATE(*(__uint32_t*)(buf_ptr+first),
436 					  *(__uint32_t*)(mem_ptr+first),
437 					  dir, ARCH_CONVERT);
438 				break;
439 			case 8:
440 				INT_XLATE(*(__uint64_t*)(buf_ptr+first),
441 					  *(__uint64_t*)(mem_ptr+first), dir, ARCH_CONVERT);
442 				break;
443 			default:
444 				ASSERT(0);
445 			}
446 		}
447 
448 		fields &= ~(1LL << f);
449 	}
450 }
451 
452 /*
453  * xfs_readsb
454  *
455  * Does the initial read of the superblock.
456  */
457 int
458 xfs_readsb(xfs_mount_t *mp)
459 {
460 	unsigned int	sector_size;
461 	unsigned int	extra_flags;
462 	xfs_buf_t	*bp;
463 	xfs_sb_t	*sbp;
464 	int		error;
465 
466 	ASSERT(mp->m_sb_bp == NULL);
467 	ASSERT(mp->m_ddev_targp != NULL);
468 
469 	/*
470 	 * Allocate a (locked) buffer to hold the superblock.
471 	 * This will be kept around at all times to optimize
472 	 * access to the superblock.
473 	 */
474 	sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
475 	extra_flags = XFS_BUF_LOCK | XFS_BUF_MANAGE | XFS_BUF_MAPPED;
476 
477 	bp = xfs_buf_read_flags(mp->m_ddev_targp, XFS_SB_DADDR,
478 				BTOBB(sector_size), extra_flags);
479 	if (!bp || XFS_BUF_ISERROR(bp)) {
480 		cmn_err(CE_WARN, "XFS: SB read failed");
481 		error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
482 		goto fail;
483 	}
484 	ASSERT(XFS_BUF_ISBUSY(bp));
485 	ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
486 
487 	/*
488 	 * Initialize the mount structure from the superblock.
489 	 * But first do some basic consistency checking.
490 	 */
491 	sbp = XFS_BUF_TO_SBP(bp);
492 	xfs_xlatesb(XFS_BUF_PTR(bp), &(mp->m_sb), 1, XFS_SB_ALL_BITS);
493 
494 	error = xfs_mount_validate_sb(mp, &(mp->m_sb));
495 	if (error) {
496 		cmn_err(CE_WARN, "XFS: SB validate failed");
497 		goto fail;
498 	}
499 
500 	/*
501 	 * We must be able to do sector-sized and sector-aligned IO.
502 	 */
503 	if (sector_size > mp->m_sb.sb_sectsize) {
504 		cmn_err(CE_WARN,
505 			"XFS: device supports only %u byte sectors (not %u)",
506 			sector_size, mp->m_sb.sb_sectsize);
507 		error = ENOSYS;
508 		goto fail;
509 	}
510 
511 	/*
512 	 * If device sector size is smaller than the superblock size,
513 	 * re-read the superblock so the buffer is correctly sized.
514 	 */
515 	if (sector_size < mp->m_sb.sb_sectsize) {
516 		XFS_BUF_UNMANAGE(bp);
517 		xfs_buf_relse(bp);
518 		sector_size = mp->m_sb.sb_sectsize;
519 		bp = xfs_buf_read_flags(mp->m_ddev_targp, XFS_SB_DADDR,
520 					BTOBB(sector_size), extra_flags);
521 		if (!bp || XFS_BUF_ISERROR(bp)) {
522 			cmn_err(CE_WARN, "XFS: SB re-read failed");
523 			error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
524 			goto fail;
525 		}
526 		ASSERT(XFS_BUF_ISBUSY(bp));
527 		ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
528 	}
529 
530 	mp->m_sb_bp = bp;
531 	xfs_buf_relse(bp);
532 	ASSERT(XFS_BUF_VALUSEMA(bp) > 0);
533 	return 0;
534 
535  fail:
536 	if (bp) {
537 		XFS_BUF_UNMANAGE(bp);
538 		xfs_buf_relse(bp);
539 	}
540 	return error;
541 }
542 
543 
544 /*
545  * xfs_mount_common
546  *
547  * Mount initialization code establishing various mount
548  * fields from the superblock associated with the given
549  * mount structure
550  */
551 STATIC void
552 xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
553 {
554 	int	i;
555 
556 	mp->m_agfrotor = mp->m_agirotor = 0;
557 	spinlock_init(&mp->m_agirotor_lock, "m_agirotor_lock");
558 	mp->m_maxagi = mp->m_sb.sb_agcount;
559 	mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
560 	mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
561 	mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
562 	mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
563 	mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
564 	mp->m_litino = sbp->sb_inodesize -
565 		((uint)sizeof(xfs_dinode_core_t) + (uint)sizeof(xfs_agino_t));
566 	mp->m_blockmask = sbp->sb_blocksize - 1;
567 	mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
568 	mp->m_blockwmask = mp->m_blockwsize - 1;
569 	INIT_LIST_HEAD(&mp->m_del_inodes);
570 
571 	/*
572 	 * Setup for attributes, in case they get created.
573 	 * This value is for inodes getting attributes for the first time,
574 	 * the per-inode value is for old attribute values.
575 	 */
576 	ASSERT(sbp->sb_inodesize >= 256 && sbp->sb_inodesize <= 2048);
577 	switch (sbp->sb_inodesize) {
578 	case 256:
579 		mp->m_attroffset = XFS_LITINO(mp) -
580 				   XFS_BMDR_SPACE_CALC(MINABTPTRS);
581 		break;
582 	case 512:
583 	case 1024:
584 	case 2048:
585 		mp->m_attroffset = XFS_BMDR_SPACE_CALC(6 * MINABTPTRS);
586 		break;
587 	default:
588 		ASSERT(0);
589 	}
590 	ASSERT(mp->m_attroffset < XFS_LITINO(mp));
591 
592 	for (i = 0; i < 2; i++) {
593 		mp->m_alloc_mxr[i] = XFS_BTREE_BLOCK_MAXRECS(sbp->sb_blocksize,
594 			xfs_alloc, i == 0);
595 		mp->m_alloc_mnr[i] = XFS_BTREE_BLOCK_MINRECS(sbp->sb_blocksize,
596 			xfs_alloc, i == 0);
597 	}
598 	for (i = 0; i < 2; i++) {
599 		mp->m_bmap_dmxr[i] = XFS_BTREE_BLOCK_MAXRECS(sbp->sb_blocksize,
600 			xfs_bmbt, i == 0);
601 		mp->m_bmap_dmnr[i] = XFS_BTREE_BLOCK_MINRECS(sbp->sb_blocksize,
602 			xfs_bmbt, i == 0);
603 	}
604 	for (i = 0; i < 2; i++) {
605 		mp->m_inobt_mxr[i] = XFS_BTREE_BLOCK_MAXRECS(sbp->sb_blocksize,
606 			xfs_inobt, i == 0);
607 		mp->m_inobt_mnr[i] = XFS_BTREE_BLOCK_MINRECS(sbp->sb_blocksize,
608 			xfs_inobt, i == 0);
609 	}
610 
611 	mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
612 	mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
613 					sbp->sb_inopblock);
614 	mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
615 }
616 /*
617  * xfs_mountfs
618  *
619  * This function does the following on an initial mount of a file system:
620  *	- reads the superblock from disk and init the mount struct
621  *	- if we're a 32-bit kernel, do a size check on the superblock
622  *		so we don't mount terabyte filesystems
623  *	- init mount struct realtime fields
624  *	- allocate inode hash table for fs
625  *	- init directory manager
626  *	- perform recovery and init the log manager
627  */
628 int
629 xfs_mountfs(
630 	vfs_t		*vfsp,
631 	xfs_mount_t	*mp,
632 	int		mfsi_flags)
633 {
634 	xfs_buf_t	*bp;
635 	xfs_sb_t	*sbp = &(mp->m_sb);
636 	xfs_inode_t	*rip;
637 	vnode_t		*rvp = NULL;
638 	int		readio_log, writeio_log;
639 	xfs_daddr_t	d;
640 	__uint64_t	ret64;
641 	__int64_t	update_flags;
642 	uint		quotamount, quotaflags;
643 	int		agno;
644 	int		uuid_mounted = 0;
645 	int		error = 0;
646 
647 	if (mp->m_sb_bp == NULL) {
648 		if ((error = xfs_readsb(mp))) {
649 			return (error);
650 		}
651 	}
652 	xfs_mount_common(mp, sbp);
653 
654 	/*
655 	 * Check if sb_agblocks is aligned at stripe boundary
656 	 * If sb_agblocks is NOT aligned turn off m_dalign since
657 	 * allocator alignment is within an ag, therefore ag has
658 	 * to be aligned at stripe boundary.
659 	 */
660 	update_flags = 0LL;
661 	if (mp->m_dalign && !(mfsi_flags & XFS_MFSI_SECOND)) {
662 		/*
663 		 * If stripe unit and stripe width are not multiples
664 		 * of the fs blocksize turn off alignment.
665 		 */
666 		if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
667 		    (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
668 			if (mp->m_flags & XFS_MOUNT_RETERR) {
669 				cmn_err(CE_WARN,
670 					"XFS: alignment check 1 failed");
671 				error = XFS_ERROR(EINVAL);
672 				goto error1;
673 			}
674 			mp->m_dalign = mp->m_swidth = 0;
675 		} else {
676 			/*
677 			 * Convert the stripe unit and width to FSBs.
678 			 */
679 			mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
680 			if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
681 				if (mp->m_flags & XFS_MOUNT_RETERR) {
682 					error = XFS_ERROR(EINVAL);
683 					goto error1;
684 				}
685 				xfs_fs_cmn_err(CE_WARN, mp,
686 "stripe alignment turned off: sunit(%d)/swidth(%d) incompatible with agsize(%d)",
687 					mp->m_dalign, mp->m_swidth,
688 					sbp->sb_agblocks);
689 
690 				mp->m_dalign = 0;
691 				mp->m_swidth = 0;
692 			} else if (mp->m_dalign) {
693 				mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
694 			} else {
695 				if (mp->m_flags & XFS_MOUNT_RETERR) {
696 					xfs_fs_cmn_err(CE_WARN, mp,
697 "stripe alignment turned off: sunit(%d) less than bsize(%d)",
698                                         	mp->m_dalign,
699 						mp->m_blockmask +1);
700 					error = XFS_ERROR(EINVAL);
701 					goto error1;
702 				}
703 				mp->m_swidth = 0;
704 			}
705 		}
706 
707 		/*
708 		 * Update superblock with new values
709 		 * and log changes
710 		 */
711 		if (XFS_SB_VERSION_HASDALIGN(sbp)) {
712 			if (sbp->sb_unit != mp->m_dalign) {
713 				sbp->sb_unit = mp->m_dalign;
714 				update_flags |= XFS_SB_UNIT;
715 			}
716 			if (sbp->sb_width != mp->m_swidth) {
717 				sbp->sb_width = mp->m_swidth;
718 				update_flags |= XFS_SB_WIDTH;
719 			}
720 		}
721 	} else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
722 		    XFS_SB_VERSION_HASDALIGN(&mp->m_sb)) {
723 			mp->m_dalign = sbp->sb_unit;
724 			mp->m_swidth = sbp->sb_width;
725 	}
726 
727 	xfs_alloc_compute_maxlevels(mp);
728 	xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
729 	xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
730 	xfs_ialloc_compute_maxlevels(mp);
731 
732 	if (sbp->sb_imax_pct) {
733 		__uint64_t	icount;
734 
735 		/* Make sure the maximum inode count is a multiple of the
736 		 * units we allocate inodes in.
737 		 */
738 
739 		icount = sbp->sb_dblocks * sbp->sb_imax_pct;
740 		do_div(icount, 100);
741 		do_div(icount, mp->m_ialloc_blks);
742 		mp->m_maxicount = (icount * mp->m_ialloc_blks)  <<
743 				   sbp->sb_inopblog;
744 	} else
745 		mp->m_maxicount = 0;
746 
747 	mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog);
748 
749 	/*
750 	 * XFS uses the uuid from the superblock as the unique
751 	 * identifier for fsid.  We can not use the uuid from the volume
752 	 * since a single partition filesystem is identical to a single
753 	 * partition volume/filesystem.
754 	 */
755 	if ((mfsi_flags & XFS_MFSI_SECOND) == 0 &&
756 	    (mp->m_flags & XFS_MOUNT_NOUUID) == 0) {
757 		if (xfs_uuid_mount(mp)) {
758 			error = XFS_ERROR(EINVAL);
759 			goto error1;
760 		}
761 		uuid_mounted=1;
762 		ret64 = uuid_hash64(&sbp->sb_uuid);
763 		memcpy(&vfsp->vfs_fsid, &ret64, sizeof(ret64));
764 	}
765 
766 	/*
767 	 * Set the default minimum read and write sizes unless
768 	 * already specified in a mount option.
769 	 * We use smaller I/O sizes when the file system
770 	 * is being used for NFS service (wsync mount option).
771 	 */
772 	if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
773 		if (mp->m_flags & XFS_MOUNT_WSYNC) {
774 			readio_log = XFS_WSYNC_READIO_LOG;
775 			writeio_log = XFS_WSYNC_WRITEIO_LOG;
776 		} else {
777 			readio_log = XFS_READIO_LOG_LARGE;
778 			writeio_log = XFS_WRITEIO_LOG_LARGE;
779 		}
780 	} else {
781 		readio_log = mp->m_readio_log;
782 		writeio_log = mp->m_writeio_log;
783 	}
784 
785 	/*
786 	 * Set the number of readahead buffers to use based on
787 	 * physical memory size.
788 	 */
789 	if (xfs_physmem <= 4096)		/* <= 16MB */
790 		mp->m_nreadaheads = XFS_RW_NREADAHEAD_16MB;
791 	else if (xfs_physmem <= 8192)	/* <= 32MB */
792 		mp->m_nreadaheads = XFS_RW_NREADAHEAD_32MB;
793 	else
794 		mp->m_nreadaheads = XFS_RW_NREADAHEAD_K32;
795 	if (sbp->sb_blocklog > readio_log) {
796 		mp->m_readio_log = sbp->sb_blocklog;
797 	} else {
798 		mp->m_readio_log = readio_log;
799 	}
800 	mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
801 	if (sbp->sb_blocklog > writeio_log) {
802 		mp->m_writeio_log = sbp->sb_blocklog;
803 	} else {
804 		mp->m_writeio_log = writeio_log;
805 	}
806 	mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
807 
808 	/*
809 	 * Set the inode cluster size based on the physical memory
810 	 * size.  This may still be overridden by the file system
811 	 * block size if it is larger than the chosen cluster size.
812 	 */
813 	if (xfs_physmem <= btoc(32 * 1024 * 1024)) { /* <= 32 MB */
814 		mp->m_inode_cluster_size = XFS_INODE_SMALL_CLUSTER_SIZE;
815 	} else {
816 		mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
817 	}
818 	/*
819 	 * Set whether we're using inode alignment.
820 	 */
821 	if (XFS_SB_VERSION_HASALIGN(&mp->m_sb) &&
822 	    mp->m_sb.sb_inoalignmt >=
823 	    XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size))
824 		mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
825 	else
826 		mp->m_inoalign_mask = 0;
827 	/*
828 	 * If we are using stripe alignment, check whether
829 	 * the stripe unit is a multiple of the inode alignment
830 	 */
831 	if (mp->m_dalign && mp->m_inoalign_mask &&
832 	    !(mp->m_dalign & mp->m_inoalign_mask))
833 		mp->m_sinoalign = mp->m_dalign;
834 	else
835 		mp->m_sinoalign = 0;
836 	/*
837 	 * Check that the data (and log if separate) are an ok size.
838 	 */
839 	d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
840 	if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
841 		cmn_err(CE_WARN, "XFS: size check 1 failed");
842 		error = XFS_ERROR(E2BIG);
843 		goto error1;
844 	}
845 	error = xfs_read_buf(mp, mp->m_ddev_targp,
846 			     d - XFS_FSS_TO_BB(mp, 1),
847 			     XFS_FSS_TO_BB(mp, 1), 0, &bp);
848 	if (!error) {
849 		xfs_buf_relse(bp);
850 	} else {
851 		cmn_err(CE_WARN, "XFS: size check 2 failed");
852 		if (error == ENOSPC) {
853 			error = XFS_ERROR(E2BIG);
854 		}
855 		goto error1;
856 	}
857 
858 	if (((mfsi_flags & XFS_MFSI_CLIENT) == 0) &&
859 	    mp->m_logdev_targp != mp->m_ddev_targp) {
860 		d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
861 		if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
862 			cmn_err(CE_WARN, "XFS: size check 3 failed");
863 			error = XFS_ERROR(E2BIG);
864 			goto error1;
865 		}
866 		error = xfs_read_buf(mp, mp->m_logdev_targp,
867 				     d - XFS_FSB_TO_BB(mp, 1),
868 				     XFS_FSB_TO_BB(mp, 1), 0, &bp);
869 		if (!error) {
870 			xfs_buf_relse(bp);
871 		} else {
872 			cmn_err(CE_WARN, "XFS: size check 3 failed");
873 			if (error == ENOSPC) {
874 				error = XFS_ERROR(E2BIG);
875 			}
876 			goto error1;
877 		}
878 	}
879 
880 	/*
881 	 * Initialize realtime fields in the mount structure
882 	 */
883 	if ((error = xfs_rtmount_init(mp))) {
884 		cmn_err(CE_WARN, "XFS: RT mount failed");
885 		goto error1;
886 	}
887 
888 	/*
889 	 * For client case we are done now
890 	 */
891 	if (mfsi_flags & XFS_MFSI_CLIENT) {
892 		return(0);
893 	}
894 
895 	/*
896 	 *  Copies the low order bits of the timestamp and the randomly
897 	 *  set "sequence" number out of a UUID.
898 	 */
899 	uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
900 
901 	/*
902 	 *  The vfs structure needs to have a file system independent
903 	 *  way of checking for the invariant file system ID.  Since it
904 	 *  can't look at mount structures it has a pointer to the data
905 	 *  in the mount structure.
906 	 *
907 	 *  File systems that don't support user level file handles (i.e.
908 	 *  all of them except for XFS) will leave vfs_altfsid as NULL.
909 	 */
910 	vfsp->vfs_altfsid = (xfs_fsid_t *)mp->m_fixedfsid;
911 	mp->m_dmevmask = 0;	/* not persistent; set after each mount */
912 
913 	/*
914 	 * Select the right directory manager.
915 	 */
916 	mp->m_dirops =
917 		XFS_SB_VERSION_HASDIRV2(&mp->m_sb) ?
918 			xfsv2_dirops :
919 			xfsv1_dirops;
920 
921 	/*
922 	 * Initialize directory manager's entries.
923 	 */
924 	XFS_DIR_MOUNT(mp);
925 
926 	/*
927 	 * Initialize the attribute manager's entries.
928 	 */
929 	mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100;
930 
931 	/*
932 	 * Initialize the precomputed transaction reservations values.
933 	 */
934 	xfs_trans_init(mp);
935 
936 	/*
937 	 * Allocate and initialize the inode hash table for this
938 	 * file system.
939 	 */
940 	xfs_ihash_init(mp);
941 	xfs_chash_init(mp);
942 
943 	/*
944 	 * Allocate and initialize the per-ag data.
945 	 */
946 	init_rwsem(&mp->m_peraglock);
947 	mp->m_perag =
948 		kmem_zalloc(sbp->sb_agcount * sizeof(xfs_perag_t), KM_SLEEP);
949 
950 	mp->m_maxagi = xfs_initialize_perag(vfsp, mp, sbp->sb_agcount);
951 
952 	/*
953 	 * log's mount-time initialization. Perform 1st part recovery if needed
954 	 */
955 	if (likely(sbp->sb_logblocks > 0)) {	/* check for volume case */
956 		error = xfs_log_mount(mp, mp->m_logdev_targp,
957 				      XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
958 				      XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
959 		if (error) {
960 			cmn_err(CE_WARN, "XFS: log mount failed");
961 			goto error2;
962 		}
963 	} else {	/* No log has been defined */
964 		cmn_err(CE_WARN, "XFS: no log defined");
965 		XFS_ERROR_REPORT("xfs_mountfs_int(1)", XFS_ERRLEVEL_LOW, mp);
966 		error = XFS_ERROR(EFSCORRUPTED);
967 		goto error2;
968 	}
969 
970 	/*
971 	 * Get and sanity-check the root inode.
972 	 * Save the pointer to it in the mount structure.
973 	 */
974 	error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip, 0);
975 	if (error) {
976 		cmn_err(CE_WARN, "XFS: failed to read root inode");
977 		goto error3;
978 	}
979 
980 	ASSERT(rip != NULL);
981 	rvp = XFS_ITOV(rip);
982 
983 	if (unlikely((rip->i_d.di_mode & S_IFMT) != S_IFDIR)) {
984 		cmn_err(CE_WARN, "XFS: corrupted root inode");
985 		prdev("Root inode %llu is not a directory",
986 		      mp->m_ddev_targp, (unsigned long long)rip->i_ino);
987 		xfs_iunlock(rip, XFS_ILOCK_EXCL);
988 		XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
989 				 mp);
990 		error = XFS_ERROR(EFSCORRUPTED);
991 		goto error4;
992 	}
993 	mp->m_rootip = rip;	/* save it */
994 
995 	xfs_iunlock(rip, XFS_ILOCK_EXCL);
996 
997 	/*
998 	 * Initialize realtime inode pointers in the mount structure
999 	 */
1000 	if ((error = xfs_rtmount_inodes(mp))) {
1001 		/*
1002 		 * Free up the root inode.
1003 		 */
1004 		cmn_err(CE_WARN, "XFS: failed to read RT inodes");
1005 		goto error4;
1006 	}
1007 
1008 	/*
1009 	 * If fs is not mounted readonly, then update the superblock
1010 	 * unit and width changes.
1011 	 */
1012 	if (update_flags && !(vfsp->vfs_flag & VFS_RDONLY))
1013 		xfs_mount_log_sbunit(mp, update_flags);
1014 
1015 	/*
1016 	 * Initialise the XFS quota management subsystem for this mount
1017 	 */
1018 	if ((error = XFS_QM_INIT(mp, &quotamount, &quotaflags)))
1019 		goto error4;
1020 
1021 	/*
1022 	 * Finish recovering the file system.  This part needed to be
1023 	 * delayed until after the root and real-time bitmap inodes
1024 	 * were consistently read in.
1025 	 */
1026 	error = xfs_log_mount_finish(mp, mfsi_flags);
1027 	if (error) {
1028 		cmn_err(CE_WARN, "XFS: log mount finish failed");
1029 		goto error4;
1030 	}
1031 
1032 	/*
1033 	 * Complete the quota initialisation, post-log-replay component.
1034 	 */
1035 	if ((error = XFS_QM_MOUNT(mp, quotamount, quotaflags, mfsi_flags)))
1036 		goto error4;
1037 
1038 	return 0;
1039 
1040  error4:
1041 	/*
1042 	 * Free up the root inode.
1043 	 */
1044 	VN_RELE(rvp);
1045  error3:
1046 	xfs_log_unmount_dealloc(mp);
1047  error2:
1048 	xfs_ihash_free(mp);
1049 	xfs_chash_free(mp);
1050 	for (agno = 0; agno < sbp->sb_agcount; agno++)
1051 		if (mp->m_perag[agno].pagb_list)
1052 			kmem_free(mp->m_perag[agno].pagb_list,
1053 			  sizeof(xfs_perag_busy_t) * XFS_PAGB_NUM_SLOTS);
1054 	kmem_free(mp->m_perag, sbp->sb_agcount * sizeof(xfs_perag_t));
1055 	mp->m_perag = NULL;
1056 	/* FALLTHROUGH */
1057  error1:
1058 	if (uuid_mounted)
1059 		xfs_uuid_unmount(mp);
1060 	xfs_freesb(mp);
1061 	return error;
1062 }
1063 
1064 /*
1065  * xfs_unmountfs
1066  *
1067  * This flushes out the inodes,dquots and the superblock, unmounts the
1068  * log and makes sure that incore structures are freed.
1069  */
1070 int
1071 xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
1072 {
1073 	struct vfs	*vfsp = XFS_MTOVFS(mp);
1074 #if defined(DEBUG) || defined(INDUCE_IO_ERROR)
1075 	int64_t		fsid;
1076 #endif
1077 
1078 	xfs_iflush_all(mp);
1079 
1080 	XFS_QM_DQPURGEALL(mp,
1081 		XFS_QMOPT_UQUOTA | XFS_QMOPT_GQUOTA | XFS_QMOPT_UMOUNTING);
1082 
1083 	/*
1084 	 * Flush out the log synchronously so that we know for sure
1085 	 * that nothing is pinned.  This is important because bflush()
1086 	 * will skip pinned buffers.
1087 	 */
1088 	xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE | XFS_LOG_SYNC);
1089 
1090 	xfs_binval(mp->m_ddev_targp);
1091 	if (mp->m_rtdev_targp) {
1092 		xfs_binval(mp->m_rtdev_targp);
1093 	}
1094 
1095 	xfs_unmountfs_writesb(mp);
1096 
1097 	xfs_unmountfs_wait(mp); 		/* wait for async bufs */
1098 
1099 	xfs_log_unmount(mp);			/* Done! No more fs ops. */
1100 
1101 	xfs_freesb(mp);
1102 
1103 	/*
1104 	 * All inodes from this mount point should be freed.
1105 	 */
1106 	ASSERT(mp->m_inodes == NULL);
1107 
1108 	xfs_unmountfs_close(mp, cr);
1109 	if ((mp->m_flags & XFS_MOUNT_NOUUID) == 0)
1110 		xfs_uuid_unmount(mp);
1111 
1112 #if defined(DEBUG) || defined(INDUCE_IO_ERROR)
1113 	/*
1114 	 * clear all error tags on this filesystem
1115 	 */
1116 	memcpy(&fsid, &vfsp->vfs_fsid, sizeof(int64_t));
1117 	xfs_errortag_clearall_umount(fsid, mp->m_fsname, 0);
1118 #endif
1119 	XFS_IODONE(vfsp);
1120 	xfs_mount_free(mp, 1);
1121 	return 0;
1122 }
1123 
1124 void
1125 xfs_unmountfs_close(xfs_mount_t *mp, struct cred *cr)
1126 {
1127 	if (mp->m_logdev_targp != mp->m_ddev_targp)
1128 		xfs_free_buftarg(mp->m_logdev_targp, 1);
1129 	if (mp->m_rtdev_targp)
1130 		xfs_free_buftarg(mp->m_rtdev_targp, 1);
1131 	xfs_free_buftarg(mp->m_ddev_targp, 0);
1132 }
1133 
1134 STATIC void
1135 xfs_unmountfs_wait(xfs_mount_t *mp)
1136 {
1137 	if (mp->m_logdev_targp != mp->m_ddev_targp)
1138 		xfs_wait_buftarg(mp->m_logdev_targp);
1139 	if (mp->m_rtdev_targp)
1140 		xfs_wait_buftarg(mp->m_rtdev_targp);
1141 	xfs_wait_buftarg(mp->m_ddev_targp);
1142 }
1143 
1144 int
1145 xfs_unmountfs_writesb(xfs_mount_t *mp)
1146 {
1147 	xfs_buf_t	*sbp;
1148 	xfs_sb_t	*sb;
1149 	int		error = 0;
1150 
1151 	/*
1152 	 * skip superblock write if fs is read-only, or
1153 	 * if we are doing a forced umount.
1154 	 */
1155 	sbp = xfs_getsb(mp, 0);
1156 	if (!(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY ||
1157 		XFS_FORCED_SHUTDOWN(mp))) {
1158 		/*
1159 		 * mark shared-readonly if desired
1160 		 */
1161 		sb = XFS_BUF_TO_SBP(sbp);
1162 		if (mp->m_mk_sharedro) {
1163 			if (!(sb->sb_flags & XFS_SBF_READONLY))
1164 				sb->sb_flags |= XFS_SBF_READONLY;
1165 			if (!XFS_SB_VERSION_HASSHARED(sb))
1166 				XFS_SB_VERSION_ADDSHARED(sb);
1167 			xfs_fs_cmn_err(CE_NOTE, mp,
1168 				"Unmounting, marking shared read-only");
1169 		}
1170 		XFS_BUF_UNDONE(sbp);
1171 		XFS_BUF_UNREAD(sbp);
1172 		XFS_BUF_UNDELAYWRITE(sbp);
1173 		XFS_BUF_WRITE(sbp);
1174 		XFS_BUF_UNASYNC(sbp);
1175 		ASSERT(XFS_BUF_TARGET(sbp) == mp->m_ddev_targp);
1176 		xfsbdstrat(mp, sbp);
1177 		/* Nevermind errors we might get here. */
1178 		error = xfs_iowait(sbp);
1179 		if (error)
1180 			xfs_ioerror_alert("xfs_unmountfs_writesb",
1181 					  mp, sbp, XFS_BUF_ADDR(sbp));
1182 		if (error && mp->m_mk_sharedro)
1183 			xfs_fs_cmn_err(CE_ALERT, mp, "Superblock write error detected while unmounting.  Filesystem may not be marked shared readonly");
1184 	}
1185 	xfs_buf_relse(sbp);
1186 	return (error);
1187 }
1188 
1189 /*
1190  * xfs_mod_sb() can be used to copy arbitrary changes to the
1191  * in-core superblock into the superblock buffer to be logged.
1192  * It does not provide the higher level of locking that is
1193  * needed to protect the in-core superblock from concurrent
1194  * access.
1195  */
1196 void
1197 xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
1198 {
1199 	xfs_buf_t	*bp;
1200 	int		first;
1201 	int		last;
1202 	xfs_mount_t	*mp;
1203 	xfs_sb_t	*sbp;
1204 	xfs_sb_field_t	f;
1205 
1206 	ASSERT(fields);
1207 	if (!fields)
1208 		return;
1209 	mp = tp->t_mountp;
1210 	bp = xfs_trans_getsb(tp, mp, 0);
1211 	sbp = XFS_BUF_TO_SBP(bp);
1212 	first = sizeof(xfs_sb_t);
1213 	last = 0;
1214 
1215 	/* translate/copy */
1216 
1217 	xfs_xlatesb(XFS_BUF_PTR(bp), &(mp->m_sb), -1, fields);
1218 
1219 	/* find modified range */
1220 
1221 	f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
1222 	ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1223 	first = xfs_sb_info[f].offset;
1224 
1225 	f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
1226 	ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1227 	last = xfs_sb_info[f + 1].offset - 1;
1228 
1229 	xfs_trans_log_buf(tp, bp, first, last);
1230 }
1231 
1232 /*
1233  * xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
1234  * a delta to a specified field in the in-core superblock.  Simply
1235  * switch on the field indicated and apply the delta to that field.
1236  * Fields are not allowed to dip below zero, so if the delta would
1237  * do this do not apply it and return EINVAL.
1238  *
1239  * The SB_LOCK must be held when this routine is called.
1240  */
1241 STATIC int
1242 xfs_mod_incore_sb_unlocked(xfs_mount_t *mp, xfs_sb_field_t field,
1243 			int delta, int rsvd)
1244 {
1245 	int		scounter;	/* short counter for 32 bit fields */
1246 	long long	lcounter;	/* long counter for 64 bit fields */
1247 	long long	res_used, rem;
1248 
1249 	/*
1250 	 * With the in-core superblock spin lock held, switch
1251 	 * on the indicated field.  Apply the delta to the
1252 	 * proper field.  If the fields value would dip below
1253 	 * 0, then do not apply the delta and return EINVAL.
1254 	 */
1255 	switch (field) {
1256 	case XFS_SBS_ICOUNT:
1257 		lcounter = (long long)mp->m_sb.sb_icount;
1258 		lcounter += delta;
1259 		if (lcounter < 0) {
1260 			ASSERT(0);
1261 			return (XFS_ERROR(EINVAL));
1262 		}
1263 		mp->m_sb.sb_icount = lcounter;
1264 		return (0);
1265 	case XFS_SBS_IFREE:
1266 		lcounter = (long long)mp->m_sb.sb_ifree;
1267 		lcounter += delta;
1268 		if (lcounter < 0) {
1269 			ASSERT(0);
1270 			return (XFS_ERROR(EINVAL));
1271 		}
1272 		mp->m_sb.sb_ifree = lcounter;
1273 		return (0);
1274 	case XFS_SBS_FDBLOCKS:
1275 
1276 		lcounter = (long long)mp->m_sb.sb_fdblocks;
1277 		res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
1278 
1279 		if (delta > 0) {		/* Putting blocks back */
1280 			if (res_used > delta) {
1281 				mp->m_resblks_avail += delta;
1282 			} else {
1283 				rem = delta - res_used;
1284 				mp->m_resblks_avail = mp->m_resblks;
1285 				lcounter += rem;
1286 			}
1287 		} else {				/* Taking blocks away */
1288 
1289 			lcounter += delta;
1290 
1291 		/*
1292 		 * If were out of blocks, use any available reserved blocks if
1293 		 * were allowed to.
1294 		 */
1295 
1296 			if (lcounter < 0) {
1297 				if (rsvd) {
1298 					lcounter = (long long)mp->m_resblks_avail + delta;
1299 					if (lcounter < 0) {
1300 						return (XFS_ERROR(ENOSPC));
1301 					}
1302 					mp->m_resblks_avail = lcounter;
1303 					return (0);
1304 				} else {	/* not reserved */
1305 					return (XFS_ERROR(ENOSPC));
1306 				}
1307 			}
1308 		}
1309 
1310 		mp->m_sb.sb_fdblocks = lcounter;
1311 		return (0);
1312 	case XFS_SBS_FREXTENTS:
1313 		lcounter = (long long)mp->m_sb.sb_frextents;
1314 		lcounter += delta;
1315 		if (lcounter < 0) {
1316 			return (XFS_ERROR(ENOSPC));
1317 		}
1318 		mp->m_sb.sb_frextents = lcounter;
1319 		return (0);
1320 	case XFS_SBS_DBLOCKS:
1321 		lcounter = (long long)mp->m_sb.sb_dblocks;
1322 		lcounter += delta;
1323 		if (lcounter < 0) {
1324 			ASSERT(0);
1325 			return (XFS_ERROR(EINVAL));
1326 		}
1327 		mp->m_sb.sb_dblocks = lcounter;
1328 		return (0);
1329 	case XFS_SBS_AGCOUNT:
1330 		scounter = mp->m_sb.sb_agcount;
1331 		scounter += delta;
1332 		if (scounter < 0) {
1333 			ASSERT(0);
1334 			return (XFS_ERROR(EINVAL));
1335 		}
1336 		mp->m_sb.sb_agcount = scounter;
1337 		return (0);
1338 	case XFS_SBS_IMAX_PCT:
1339 		scounter = mp->m_sb.sb_imax_pct;
1340 		scounter += delta;
1341 		if (scounter < 0) {
1342 			ASSERT(0);
1343 			return (XFS_ERROR(EINVAL));
1344 		}
1345 		mp->m_sb.sb_imax_pct = scounter;
1346 		return (0);
1347 	case XFS_SBS_REXTSIZE:
1348 		scounter = mp->m_sb.sb_rextsize;
1349 		scounter += delta;
1350 		if (scounter < 0) {
1351 			ASSERT(0);
1352 			return (XFS_ERROR(EINVAL));
1353 		}
1354 		mp->m_sb.sb_rextsize = scounter;
1355 		return (0);
1356 	case XFS_SBS_RBMBLOCKS:
1357 		scounter = mp->m_sb.sb_rbmblocks;
1358 		scounter += delta;
1359 		if (scounter < 0) {
1360 			ASSERT(0);
1361 			return (XFS_ERROR(EINVAL));
1362 		}
1363 		mp->m_sb.sb_rbmblocks = scounter;
1364 		return (0);
1365 	case XFS_SBS_RBLOCKS:
1366 		lcounter = (long long)mp->m_sb.sb_rblocks;
1367 		lcounter += delta;
1368 		if (lcounter < 0) {
1369 			ASSERT(0);
1370 			return (XFS_ERROR(EINVAL));
1371 		}
1372 		mp->m_sb.sb_rblocks = lcounter;
1373 		return (0);
1374 	case XFS_SBS_REXTENTS:
1375 		lcounter = (long long)mp->m_sb.sb_rextents;
1376 		lcounter += delta;
1377 		if (lcounter < 0) {
1378 			ASSERT(0);
1379 			return (XFS_ERROR(EINVAL));
1380 		}
1381 		mp->m_sb.sb_rextents = lcounter;
1382 		return (0);
1383 	case XFS_SBS_REXTSLOG:
1384 		scounter = mp->m_sb.sb_rextslog;
1385 		scounter += delta;
1386 		if (scounter < 0) {
1387 			ASSERT(0);
1388 			return (XFS_ERROR(EINVAL));
1389 		}
1390 		mp->m_sb.sb_rextslog = scounter;
1391 		return (0);
1392 	default:
1393 		ASSERT(0);
1394 		return (XFS_ERROR(EINVAL));
1395 	}
1396 }
1397 
1398 /*
1399  * xfs_mod_incore_sb() is used to change a field in the in-core
1400  * superblock structure by the specified delta.  This modification
1401  * is protected by the SB_LOCK.  Just use the xfs_mod_incore_sb_unlocked()
1402  * routine to do the work.
1403  */
1404 int
1405 xfs_mod_incore_sb(xfs_mount_t *mp, xfs_sb_field_t field, int delta, int rsvd)
1406 {
1407 	unsigned long	s;
1408 	int	status;
1409 
1410 	s = XFS_SB_LOCK(mp);
1411 	status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
1412 	XFS_SB_UNLOCK(mp, s);
1413 	return (status);
1414 }
1415 
1416 /*
1417  * xfs_mod_incore_sb_batch() is used to change more than one field
1418  * in the in-core superblock structure at a time.  This modification
1419  * is protected by a lock internal to this module.  The fields and
1420  * changes to those fields are specified in the array of xfs_mod_sb
1421  * structures passed in.
1422  *
1423  * Either all of the specified deltas will be applied or none of
1424  * them will.  If any modified field dips below 0, then all modifications
1425  * will be backed out and EINVAL will be returned.
1426  */
1427 int
1428 xfs_mod_incore_sb_batch(xfs_mount_t *mp, xfs_mod_sb_t *msb, uint nmsb, int rsvd)
1429 {
1430 	unsigned long	s;
1431 	int		status=0;
1432 	xfs_mod_sb_t	*msbp;
1433 
1434 	/*
1435 	 * Loop through the array of mod structures and apply each
1436 	 * individually.  If any fail, then back out all those
1437 	 * which have already been applied.  Do all of this within
1438 	 * the scope of the SB_LOCK so that all of the changes will
1439 	 * be atomic.
1440 	 */
1441 	s = XFS_SB_LOCK(mp);
1442 	msbp = &msb[0];
1443 	for (msbp = &msbp[0]; msbp < (msb + nmsb); msbp++) {
1444 		/*
1445 		 * Apply the delta at index n.  If it fails, break
1446 		 * from the loop so we'll fall into the undo loop
1447 		 * below.
1448 		 */
1449 		status = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1450 						    msbp->msb_delta, rsvd);
1451 		if (status != 0) {
1452 			break;
1453 		}
1454 	}
1455 
1456 	/*
1457 	 * If we didn't complete the loop above, then back out
1458 	 * any changes made to the superblock.  If you add code
1459 	 * between the loop above and here, make sure that you
1460 	 * preserve the value of status. Loop back until
1461 	 * we step below the beginning of the array.  Make sure
1462 	 * we don't touch anything back there.
1463 	 */
1464 	if (status != 0) {
1465 		msbp--;
1466 		while (msbp >= msb) {
1467 			status = xfs_mod_incore_sb_unlocked(mp,
1468 				    msbp->msb_field, -(msbp->msb_delta), rsvd);
1469 			ASSERT(status == 0);
1470 			msbp--;
1471 		}
1472 	}
1473 	XFS_SB_UNLOCK(mp, s);
1474 	return (status);
1475 }
1476 
1477 /*
1478  * xfs_getsb() is called to obtain the buffer for the superblock.
1479  * The buffer is returned locked and read in from disk.
1480  * The buffer should be released with a call to xfs_brelse().
1481  *
1482  * If the flags parameter is BUF_TRYLOCK, then we'll only return
1483  * the superblock buffer if it can be locked without sleeping.
1484  * If it can't then we'll return NULL.
1485  */
1486 xfs_buf_t *
1487 xfs_getsb(
1488 	xfs_mount_t	*mp,
1489 	int		flags)
1490 {
1491 	xfs_buf_t	*bp;
1492 
1493 	ASSERT(mp->m_sb_bp != NULL);
1494 	bp = mp->m_sb_bp;
1495 	if (flags & XFS_BUF_TRYLOCK) {
1496 		if (!XFS_BUF_CPSEMA(bp)) {
1497 			return NULL;
1498 		}
1499 	} else {
1500 		XFS_BUF_PSEMA(bp, PRIBIO);
1501 	}
1502 	XFS_BUF_HOLD(bp);
1503 	ASSERT(XFS_BUF_ISDONE(bp));
1504 	return (bp);
1505 }
1506 
1507 /*
1508  * Used to free the superblock along various error paths.
1509  */
1510 void
1511 xfs_freesb(
1512 	xfs_mount_t	*mp)
1513 {
1514 	xfs_buf_t	*bp;
1515 
1516 	/*
1517 	 * Use xfs_getsb() so that the buffer will be locked
1518 	 * when we call xfs_buf_relse().
1519 	 */
1520 	bp = xfs_getsb(mp, 0);
1521 	XFS_BUF_UNMANAGE(bp);
1522 	xfs_buf_relse(bp);
1523 	mp->m_sb_bp = NULL;
1524 }
1525 
1526 /*
1527  * See if the UUID is unique among mounted XFS filesystems.
1528  * Mount fails if UUID is nil or a FS with the same UUID is already mounted.
1529  */
1530 STATIC int
1531 xfs_uuid_mount(
1532 	xfs_mount_t	*mp)
1533 {
1534 	if (uuid_is_nil(&mp->m_sb.sb_uuid)) {
1535 		cmn_err(CE_WARN,
1536 			"XFS: Filesystem %s has nil UUID - can't mount",
1537 			mp->m_fsname);
1538 		return -1;
1539 	}
1540 	if (!uuid_table_insert(&mp->m_sb.sb_uuid)) {
1541 		cmn_err(CE_WARN,
1542 			"XFS: Filesystem %s has duplicate UUID - can't mount",
1543 			mp->m_fsname);
1544 		return -1;
1545 	}
1546 	return 0;
1547 }
1548 
1549 /*
1550  * Remove filesystem from the UUID table.
1551  */
1552 STATIC void
1553 xfs_uuid_unmount(
1554 	xfs_mount_t	*mp)
1555 {
1556 	uuid_table_remove(&mp->m_sb.sb_uuid);
1557 }
1558 
1559 /*
1560  * Used to log changes to the superblock unit and width fields which could
1561  * be altered by the mount options. Only the first superblock is updated.
1562  */
1563 STATIC void
1564 xfs_mount_log_sbunit(
1565 	xfs_mount_t	*mp,
1566 	__int64_t	fields)
1567 {
1568 	xfs_trans_t	*tp;
1569 
1570 	ASSERT(fields & (XFS_SB_UNIT|XFS_SB_WIDTH|XFS_SB_UUID));
1571 
1572 	tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
1573 	if (xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1574 				XFS_DEFAULT_LOG_COUNT)) {
1575 		xfs_trans_cancel(tp, 0);
1576 		return;
1577 	}
1578 	xfs_mod_sb(tp, fields);
1579 	xfs_trans_commit(tp, 0, NULL);
1580 }
1581