Merge branch 'firewire-kernel-streaming' of git://git.alsa-project.org/alsa-kprivate
[firewire-audio.git] / fs / xfs / xfs_mount.c
blobd447aef84bc3a552fe44fdd1559bbf05d3f5f17f
1 /*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
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.
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.
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
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_dir2.h"
28 #include "xfs_mount.h"
29 #include "xfs_bmap_btree.h"
30 #include "xfs_alloc_btree.h"
31 #include "xfs_ialloc_btree.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_btree.h"
35 #include "xfs_ialloc.h"
36 #include "xfs_alloc.h"
37 #include "xfs_rtalloc.h"
38 #include "xfs_bmap.h"
39 #include "xfs_error.h"
40 #include "xfs_rw.h"
41 #include "xfs_quota.h"
42 #include "xfs_fsops.h"
43 #include "xfs_utils.h"
44 #include "xfs_trace.h"
47 STATIC void xfs_unmountfs_wait(xfs_mount_t *);
50 #ifdef HAVE_PERCPU_SB
51 STATIC void xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t,
52 int);
53 STATIC void xfs_icsb_balance_counter_locked(xfs_mount_t *, xfs_sb_field_t,
54 int);
55 STATIC void xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
56 #else
58 #define xfs_icsb_balance_counter(mp, a, b) do { } while (0)
59 #define xfs_icsb_balance_counter_locked(mp, a, b) do { } while (0)
60 #endif
62 static const struct {
63 short offset;
64 short type; /* 0 = integer
65 * 1 = binary / string (no translation)
67 } xfs_sb_info[] = {
68 { offsetof(xfs_sb_t, sb_magicnum), 0 },
69 { offsetof(xfs_sb_t, sb_blocksize), 0 },
70 { offsetof(xfs_sb_t, sb_dblocks), 0 },
71 { offsetof(xfs_sb_t, sb_rblocks), 0 },
72 { offsetof(xfs_sb_t, sb_rextents), 0 },
73 { offsetof(xfs_sb_t, sb_uuid), 1 },
74 { offsetof(xfs_sb_t, sb_logstart), 0 },
75 { offsetof(xfs_sb_t, sb_rootino), 0 },
76 { offsetof(xfs_sb_t, sb_rbmino), 0 },
77 { offsetof(xfs_sb_t, sb_rsumino), 0 },
78 { offsetof(xfs_sb_t, sb_rextsize), 0 },
79 { offsetof(xfs_sb_t, sb_agblocks), 0 },
80 { offsetof(xfs_sb_t, sb_agcount), 0 },
81 { offsetof(xfs_sb_t, sb_rbmblocks), 0 },
82 { offsetof(xfs_sb_t, sb_logblocks), 0 },
83 { offsetof(xfs_sb_t, sb_versionnum), 0 },
84 { offsetof(xfs_sb_t, sb_sectsize), 0 },
85 { offsetof(xfs_sb_t, sb_inodesize), 0 },
86 { offsetof(xfs_sb_t, sb_inopblock), 0 },
87 { offsetof(xfs_sb_t, sb_fname[0]), 1 },
88 { offsetof(xfs_sb_t, sb_blocklog), 0 },
89 { offsetof(xfs_sb_t, sb_sectlog), 0 },
90 { offsetof(xfs_sb_t, sb_inodelog), 0 },
91 { offsetof(xfs_sb_t, sb_inopblog), 0 },
92 { offsetof(xfs_sb_t, sb_agblklog), 0 },
93 { offsetof(xfs_sb_t, sb_rextslog), 0 },
94 { offsetof(xfs_sb_t, sb_inprogress), 0 },
95 { offsetof(xfs_sb_t, sb_imax_pct), 0 },
96 { offsetof(xfs_sb_t, sb_icount), 0 },
97 { offsetof(xfs_sb_t, sb_ifree), 0 },
98 { offsetof(xfs_sb_t, sb_fdblocks), 0 },
99 { offsetof(xfs_sb_t, sb_frextents), 0 },
100 { offsetof(xfs_sb_t, sb_uquotino), 0 },
101 { offsetof(xfs_sb_t, sb_gquotino), 0 },
102 { offsetof(xfs_sb_t, sb_qflags), 0 },
103 { offsetof(xfs_sb_t, sb_flags), 0 },
104 { offsetof(xfs_sb_t, sb_shared_vn), 0 },
105 { offsetof(xfs_sb_t, sb_inoalignmt), 0 },
106 { offsetof(xfs_sb_t, sb_unit), 0 },
107 { offsetof(xfs_sb_t, sb_width), 0 },
108 { offsetof(xfs_sb_t, sb_dirblklog), 0 },
109 { offsetof(xfs_sb_t, sb_logsectlog), 0 },
110 { offsetof(xfs_sb_t, sb_logsectsize),0 },
111 { offsetof(xfs_sb_t, sb_logsunit), 0 },
112 { offsetof(xfs_sb_t, sb_features2), 0 },
113 { offsetof(xfs_sb_t, sb_bad_features2), 0 },
114 { sizeof(xfs_sb_t), 0 }
117 static DEFINE_MUTEX(xfs_uuid_table_mutex);
118 static int xfs_uuid_table_size;
119 static uuid_t *xfs_uuid_table;
122 * See if the UUID is unique among mounted XFS filesystems.
123 * Mount fails if UUID is nil or a FS with the same UUID is already mounted.
125 STATIC int
126 xfs_uuid_mount(
127 struct xfs_mount *mp)
129 uuid_t *uuid = &mp->m_sb.sb_uuid;
130 int hole, i;
132 if (mp->m_flags & XFS_MOUNT_NOUUID)
133 return 0;
135 if (uuid_is_nil(uuid)) {
136 cmn_err(CE_WARN,
137 "XFS: Filesystem %s has nil UUID - can't mount",
138 mp->m_fsname);
139 return XFS_ERROR(EINVAL);
142 mutex_lock(&xfs_uuid_table_mutex);
143 for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
144 if (uuid_is_nil(&xfs_uuid_table[i])) {
145 hole = i;
146 continue;
148 if (uuid_equal(uuid, &xfs_uuid_table[i]))
149 goto out_duplicate;
152 if (hole < 0) {
153 xfs_uuid_table = kmem_realloc(xfs_uuid_table,
154 (xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
155 xfs_uuid_table_size * sizeof(*xfs_uuid_table),
156 KM_SLEEP);
157 hole = xfs_uuid_table_size++;
159 xfs_uuid_table[hole] = *uuid;
160 mutex_unlock(&xfs_uuid_table_mutex);
162 return 0;
164 out_duplicate:
165 mutex_unlock(&xfs_uuid_table_mutex);
166 cmn_err(CE_WARN, "XFS: Filesystem %s has duplicate UUID - can't mount",
167 mp->m_fsname);
168 return XFS_ERROR(EINVAL);
171 STATIC void
172 xfs_uuid_unmount(
173 struct xfs_mount *mp)
175 uuid_t *uuid = &mp->m_sb.sb_uuid;
176 int i;
178 if (mp->m_flags & XFS_MOUNT_NOUUID)
179 return;
181 mutex_lock(&xfs_uuid_table_mutex);
182 for (i = 0; i < xfs_uuid_table_size; i++) {
183 if (uuid_is_nil(&xfs_uuid_table[i]))
184 continue;
185 if (!uuid_equal(uuid, &xfs_uuid_table[i]))
186 continue;
187 memset(&xfs_uuid_table[i], 0, sizeof(uuid_t));
188 break;
190 ASSERT(i < xfs_uuid_table_size);
191 mutex_unlock(&xfs_uuid_table_mutex);
196 * Reference counting access wrappers to the perag structures.
197 * Because we never free per-ag structures, the only thing we
198 * have to protect against changes is the tree structure itself.
200 struct xfs_perag *
201 xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
203 struct xfs_perag *pag;
204 int ref = 0;
206 rcu_read_lock();
207 pag = radix_tree_lookup(&mp->m_perag_tree, agno);
208 if (pag) {
209 ASSERT(atomic_read(&pag->pag_ref) >= 0);
210 ref = atomic_inc_return(&pag->pag_ref);
212 rcu_read_unlock();
213 trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
214 return pag;
218 * search from @first to find the next perag with the given tag set.
220 struct xfs_perag *
221 xfs_perag_get_tag(
222 struct xfs_mount *mp,
223 xfs_agnumber_t first,
224 int tag)
226 struct xfs_perag *pag;
227 int found;
228 int ref;
230 rcu_read_lock();
231 found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
232 (void **)&pag, first, 1, tag);
233 if (found <= 0) {
234 rcu_read_unlock();
235 return NULL;
237 ref = atomic_inc_return(&pag->pag_ref);
238 rcu_read_unlock();
239 trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
240 return pag;
243 void
244 xfs_perag_put(struct xfs_perag *pag)
246 int ref;
248 ASSERT(atomic_read(&pag->pag_ref) > 0);
249 ref = atomic_dec_return(&pag->pag_ref);
250 trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
253 STATIC void
254 __xfs_free_perag(
255 struct rcu_head *head)
257 struct xfs_perag *pag = container_of(head, struct xfs_perag, rcu_head);
259 ASSERT(atomic_read(&pag->pag_ref) == 0);
260 kmem_free(pag);
264 * Free up the per-ag resources associated with the mount structure.
266 STATIC void
267 xfs_free_perag(
268 xfs_mount_t *mp)
270 xfs_agnumber_t agno;
271 struct xfs_perag *pag;
273 for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
274 spin_lock(&mp->m_perag_lock);
275 pag = radix_tree_delete(&mp->m_perag_tree, agno);
276 spin_unlock(&mp->m_perag_lock);
277 ASSERT(pag);
278 ASSERT(atomic_read(&pag->pag_ref) == 0);
279 call_rcu(&pag->rcu_head, __xfs_free_perag);
284 * Check size of device based on the (data/realtime) block count.
285 * Note: this check is used by the growfs code as well as mount.
288 xfs_sb_validate_fsb_count(
289 xfs_sb_t *sbp,
290 __uint64_t nblocks)
292 ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
293 ASSERT(sbp->sb_blocklog >= BBSHIFT);
295 #if XFS_BIG_BLKNOS /* Limited by ULONG_MAX of page cache index */
296 if (nblocks >> (PAGE_CACHE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
297 return EFBIG;
298 #else /* Limited by UINT_MAX of sectors */
299 if (nblocks << (sbp->sb_blocklog - BBSHIFT) > UINT_MAX)
300 return EFBIG;
301 #endif
302 return 0;
306 * Check the validity of the SB found.
308 STATIC int
309 xfs_mount_validate_sb(
310 xfs_mount_t *mp,
311 xfs_sb_t *sbp,
312 int flags)
315 * If the log device and data device have the
316 * same device number, the log is internal.
317 * Consequently, the sb_logstart should be non-zero. If
318 * we have a zero sb_logstart in this case, we may be trying to mount
319 * a volume filesystem in a non-volume manner.
321 if (sbp->sb_magicnum != XFS_SB_MAGIC) {
322 xfs_fs_mount_cmn_err(flags, "bad magic number");
323 return XFS_ERROR(EWRONGFS);
326 if (!xfs_sb_good_version(sbp)) {
327 xfs_fs_mount_cmn_err(flags, "bad version");
328 return XFS_ERROR(EWRONGFS);
331 if (unlikely(
332 sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
333 xfs_fs_mount_cmn_err(flags,
334 "filesystem is marked as having an external log; "
335 "specify logdev on the\nmount command line.");
336 return XFS_ERROR(EINVAL);
339 if (unlikely(
340 sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
341 xfs_fs_mount_cmn_err(flags,
342 "filesystem is marked as having an internal log; "
343 "do not specify logdev on\nthe mount command line.");
344 return XFS_ERROR(EINVAL);
348 * More sanity checking. These were stolen directly from
349 * xfs_repair.
351 if (unlikely(
352 sbp->sb_agcount <= 0 ||
353 sbp->sb_sectsize < XFS_MIN_SECTORSIZE ||
354 sbp->sb_sectsize > XFS_MAX_SECTORSIZE ||
355 sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG ||
356 sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG ||
357 sbp->sb_sectsize != (1 << sbp->sb_sectlog) ||
358 sbp->sb_blocksize < XFS_MIN_BLOCKSIZE ||
359 sbp->sb_blocksize > XFS_MAX_BLOCKSIZE ||
360 sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG ||
361 sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
362 sbp->sb_blocksize != (1 << sbp->sb_blocklog) ||
363 sbp->sb_inodesize < XFS_DINODE_MIN_SIZE ||
364 sbp->sb_inodesize > XFS_DINODE_MAX_SIZE ||
365 sbp->sb_inodelog < XFS_DINODE_MIN_LOG ||
366 sbp->sb_inodelog > XFS_DINODE_MAX_LOG ||
367 sbp->sb_inodesize != (1 << sbp->sb_inodelog) ||
368 (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) ||
369 (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) ||
370 (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) ||
371 (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */))) {
372 xfs_fs_mount_cmn_err(flags, "SB sanity check 1 failed");
373 return XFS_ERROR(EFSCORRUPTED);
377 * Sanity check AG count, size fields against data size field
379 if (unlikely(
380 sbp->sb_dblocks == 0 ||
381 sbp->sb_dblocks >
382 (xfs_drfsbno_t)sbp->sb_agcount * sbp->sb_agblocks ||
383 sbp->sb_dblocks < (xfs_drfsbno_t)(sbp->sb_agcount - 1) *
384 sbp->sb_agblocks + XFS_MIN_AG_BLOCKS)) {
385 xfs_fs_mount_cmn_err(flags, "SB sanity check 2 failed");
386 return XFS_ERROR(EFSCORRUPTED);
390 * Until this is fixed only page-sized or smaller data blocks work.
392 if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
393 xfs_fs_mount_cmn_err(flags,
394 "file system with blocksize %d bytes",
395 sbp->sb_blocksize);
396 xfs_fs_mount_cmn_err(flags,
397 "only pagesize (%ld) or less will currently work.",
398 PAGE_SIZE);
399 return XFS_ERROR(ENOSYS);
403 * Currently only very few inode sizes are supported.
405 switch (sbp->sb_inodesize) {
406 case 256:
407 case 512:
408 case 1024:
409 case 2048:
410 break;
411 default:
412 xfs_fs_mount_cmn_err(flags,
413 "inode size of %d bytes not supported",
414 sbp->sb_inodesize);
415 return XFS_ERROR(ENOSYS);
418 if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
419 xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
420 xfs_fs_mount_cmn_err(flags,
421 "file system too large to be mounted on this system.");
422 return XFS_ERROR(EFBIG);
425 if (unlikely(sbp->sb_inprogress)) {
426 xfs_fs_mount_cmn_err(flags, "file system busy");
427 return XFS_ERROR(EFSCORRUPTED);
431 * Version 1 directory format has never worked on Linux.
433 if (unlikely(!xfs_sb_version_hasdirv2(sbp))) {
434 xfs_fs_mount_cmn_err(flags,
435 "file system using version 1 directory format");
436 return XFS_ERROR(ENOSYS);
439 return 0;
443 xfs_initialize_perag(
444 xfs_mount_t *mp,
445 xfs_agnumber_t agcount,
446 xfs_agnumber_t *maxagi)
448 xfs_agnumber_t index, max_metadata;
449 xfs_agnumber_t first_initialised = 0;
450 xfs_perag_t *pag;
451 xfs_agino_t agino;
452 xfs_ino_t ino;
453 xfs_sb_t *sbp = &mp->m_sb;
454 int error = -ENOMEM;
457 * Walk the current per-ag tree so we don't try to initialise AGs
458 * that already exist (growfs case). Allocate and insert all the
459 * AGs we don't find ready for initialisation.
461 for (index = 0; index < agcount; index++) {
462 pag = xfs_perag_get(mp, index);
463 if (pag) {
464 xfs_perag_put(pag);
465 continue;
467 if (!first_initialised)
468 first_initialised = index;
470 pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
471 if (!pag)
472 goto out_unwind;
473 pag->pag_agno = index;
474 pag->pag_mount = mp;
475 spin_lock_init(&pag->pag_ici_lock);
476 mutex_init(&pag->pag_ici_reclaim_lock);
477 INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
478 spin_lock_init(&pag->pag_buf_lock);
479 pag->pag_buf_tree = RB_ROOT;
481 if (radix_tree_preload(GFP_NOFS))
482 goto out_unwind;
484 spin_lock(&mp->m_perag_lock);
485 if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
486 BUG();
487 spin_unlock(&mp->m_perag_lock);
488 radix_tree_preload_end();
489 error = -EEXIST;
490 goto out_unwind;
492 spin_unlock(&mp->m_perag_lock);
493 radix_tree_preload_end();
497 * If we mount with the inode64 option, or no inode overflows
498 * the legacy 32-bit address space clear the inode32 option.
500 agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
501 ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
503 if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
504 mp->m_flags |= XFS_MOUNT_32BITINODES;
505 else
506 mp->m_flags &= ~XFS_MOUNT_32BITINODES;
508 if (mp->m_flags & XFS_MOUNT_32BITINODES) {
510 * Calculate how much should be reserved for inodes to meet
511 * the max inode percentage.
513 if (mp->m_maxicount) {
514 __uint64_t icount;
516 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
517 do_div(icount, 100);
518 icount += sbp->sb_agblocks - 1;
519 do_div(icount, sbp->sb_agblocks);
520 max_metadata = icount;
521 } else {
522 max_metadata = agcount;
525 for (index = 0; index < agcount; index++) {
526 ino = XFS_AGINO_TO_INO(mp, index, agino);
527 if (ino > XFS_MAXINUMBER_32) {
528 index++;
529 break;
532 pag = xfs_perag_get(mp, index);
533 pag->pagi_inodeok = 1;
534 if (index < max_metadata)
535 pag->pagf_metadata = 1;
536 xfs_perag_put(pag);
538 } else {
539 for (index = 0; index < agcount; index++) {
540 pag = xfs_perag_get(mp, index);
541 pag->pagi_inodeok = 1;
542 xfs_perag_put(pag);
546 if (maxagi)
547 *maxagi = index;
548 return 0;
550 out_unwind:
551 kmem_free(pag);
552 for (; index > first_initialised; index--) {
553 pag = radix_tree_delete(&mp->m_perag_tree, index);
554 kmem_free(pag);
556 return error;
559 void
560 xfs_sb_from_disk(
561 xfs_sb_t *to,
562 xfs_dsb_t *from)
564 to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
565 to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
566 to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
567 to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
568 to->sb_rextents = be64_to_cpu(from->sb_rextents);
569 memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
570 to->sb_logstart = be64_to_cpu(from->sb_logstart);
571 to->sb_rootino = be64_to_cpu(from->sb_rootino);
572 to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
573 to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
574 to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
575 to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
576 to->sb_agcount = be32_to_cpu(from->sb_agcount);
577 to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
578 to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
579 to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
580 to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
581 to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
582 to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
583 memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
584 to->sb_blocklog = from->sb_blocklog;
585 to->sb_sectlog = from->sb_sectlog;
586 to->sb_inodelog = from->sb_inodelog;
587 to->sb_inopblog = from->sb_inopblog;
588 to->sb_agblklog = from->sb_agblklog;
589 to->sb_rextslog = from->sb_rextslog;
590 to->sb_inprogress = from->sb_inprogress;
591 to->sb_imax_pct = from->sb_imax_pct;
592 to->sb_icount = be64_to_cpu(from->sb_icount);
593 to->sb_ifree = be64_to_cpu(from->sb_ifree);
594 to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
595 to->sb_frextents = be64_to_cpu(from->sb_frextents);
596 to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
597 to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
598 to->sb_qflags = be16_to_cpu(from->sb_qflags);
599 to->sb_flags = from->sb_flags;
600 to->sb_shared_vn = from->sb_shared_vn;
601 to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
602 to->sb_unit = be32_to_cpu(from->sb_unit);
603 to->sb_width = be32_to_cpu(from->sb_width);
604 to->sb_dirblklog = from->sb_dirblklog;
605 to->sb_logsectlog = from->sb_logsectlog;
606 to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
607 to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
608 to->sb_features2 = be32_to_cpu(from->sb_features2);
609 to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
613 * Copy in core superblock to ondisk one.
615 * The fields argument is mask of superblock fields to copy.
617 void
618 xfs_sb_to_disk(
619 xfs_dsb_t *to,
620 xfs_sb_t *from,
621 __int64_t fields)
623 xfs_caddr_t to_ptr = (xfs_caddr_t)to;
624 xfs_caddr_t from_ptr = (xfs_caddr_t)from;
625 xfs_sb_field_t f;
626 int first;
627 int size;
629 ASSERT(fields);
630 if (!fields)
631 return;
633 while (fields) {
634 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
635 first = xfs_sb_info[f].offset;
636 size = xfs_sb_info[f + 1].offset - first;
638 ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
640 if (size == 1 || xfs_sb_info[f].type == 1) {
641 memcpy(to_ptr + first, from_ptr + first, size);
642 } else {
643 switch (size) {
644 case 2:
645 *(__be16 *)(to_ptr + first) =
646 cpu_to_be16(*(__u16 *)(from_ptr + first));
647 break;
648 case 4:
649 *(__be32 *)(to_ptr + first) =
650 cpu_to_be32(*(__u32 *)(from_ptr + first));
651 break;
652 case 8:
653 *(__be64 *)(to_ptr + first) =
654 cpu_to_be64(*(__u64 *)(from_ptr + first));
655 break;
656 default:
657 ASSERT(0);
661 fields &= ~(1LL << f);
666 * xfs_readsb
668 * Does the initial read of the superblock.
671 xfs_readsb(xfs_mount_t *mp, int flags)
673 unsigned int sector_size;
674 xfs_buf_t *bp;
675 int error;
677 ASSERT(mp->m_sb_bp == NULL);
678 ASSERT(mp->m_ddev_targp != NULL);
681 * Allocate a (locked) buffer to hold the superblock.
682 * This will be kept around at all times to optimize
683 * access to the superblock.
685 sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
687 reread:
688 bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
689 XFS_SB_DADDR, sector_size, 0);
690 if (!bp) {
691 xfs_fs_mount_cmn_err(flags, "SB buffer read failed");
692 return EIO;
696 * Initialize the mount structure from the superblock.
697 * But first do some basic consistency checking.
699 xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
700 error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
701 if (error) {
702 xfs_fs_mount_cmn_err(flags, "SB validate failed");
703 goto release_buf;
707 * We must be able to do sector-sized and sector-aligned IO.
709 if (sector_size > mp->m_sb.sb_sectsize) {
710 xfs_fs_mount_cmn_err(flags,
711 "device supports only %u byte sectors (not %u)",
712 sector_size, mp->m_sb.sb_sectsize);
713 error = ENOSYS;
714 goto release_buf;
718 * If device sector size is smaller than the superblock size,
719 * re-read the superblock so the buffer is correctly sized.
721 if (sector_size < mp->m_sb.sb_sectsize) {
722 xfs_buf_relse(bp);
723 sector_size = mp->m_sb.sb_sectsize;
724 goto reread;
727 /* Initialize per-cpu counters */
728 xfs_icsb_reinit_counters(mp);
730 mp->m_sb_bp = bp;
731 xfs_buf_unlock(bp);
732 return 0;
734 release_buf:
735 xfs_buf_relse(bp);
736 return error;
741 * xfs_mount_common
743 * Mount initialization code establishing various mount
744 * fields from the superblock associated with the given
745 * mount structure
747 STATIC void
748 xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
750 mp->m_agfrotor = mp->m_agirotor = 0;
751 spin_lock_init(&mp->m_agirotor_lock);
752 mp->m_maxagi = mp->m_sb.sb_agcount;
753 mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
754 mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
755 mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
756 mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
757 mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
758 mp->m_blockmask = sbp->sb_blocksize - 1;
759 mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
760 mp->m_blockwmask = mp->m_blockwsize - 1;
762 mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
763 mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
764 mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
765 mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
767 mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
768 mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
769 mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
770 mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
772 mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
773 mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
774 mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
775 mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
777 mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
778 mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
779 sbp->sb_inopblock);
780 mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
784 * xfs_initialize_perag_data
786 * Read in each per-ag structure so we can count up the number of
787 * allocated inodes, free inodes and used filesystem blocks as this
788 * information is no longer persistent in the superblock. Once we have
789 * this information, write it into the in-core superblock structure.
791 STATIC int
792 xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount)
794 xfs_agnumber_t index;
795 xfs_perag_t *pag;
796 xfs_sb_t *sbp = &mp->m_sb;
797 uint64_t ifree = 0;
798 uint64_t ialloc = 0;
799 uint64_t bfree = 0;
800 uint64_t bfreelst = 0;
801 uint64_t btree = 0;
802 int error;
804 for (index = 0; index < agcount; index++) {
806 * read the agf, then the agi. This gets us
807 * all the information we need and populates the
808 * per-ag structures for us.
810 error = xfs_alloc_pagf_init(mp, NULL, index, 0);
811 if (error)
812 return error;
814 error = xfs_ialloc_pagi_init(mp, NULL, index);
815 if (error)
816 return error;
817 pag = xfs_perag_get(mp, index);
818 ifree += pag->pagi_freecount;
819 ialloc += pag->pagi_count;
820 bfree += pag->pagf_freeblks;
821 bfreelst += pag->pagf_flcount;
822 btree += pag->pagf_btreeblks;
823 xfs_perag_put(pag);
826 * Overwrite incore superblock counters with just-read data
828 spin_lock(&mp->m_sb_lock);
829 sbp->sb_ifree = ifree;
830 sbp->sb_icount = ialloc;
831 sbp->sb_fdblocks = bfree + bfreelst + btree;
832 spin_unlock(&mp->m_sb_lock);
834 /* Fixup the per-cpu counters as well. */
835 xfs_icsb_reinit_counters(mp);
837 return 0;
841 * Update alignment values based on mount options and sb values
843 STATIC int
844 xfs_update_alignment(xfs_mount_t *mp)
846 xfs_sb_t *sbp = &(mp->m_sb);
848 if (mp->m_dalign) {
850 * If stripe unit and stripe width are not multiples
851 * of the fs blocksize turn off alignment.
853 if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
854 (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
855 if (mp->m_flags & XFS_MOUNT_RETERR) {
856 cmn_err(CE_WARN,
857 "XFS: alignment check 1 failed");
858 return XFS_ERROR(EINVAL);
860 mp->m_dalign = mp->m_swidth = 0;
861 } else {
863 * Convert the stripe unit and width to FSBs.
865 mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
866 if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
867 if (mp->m_flags & XFS_MOUNT_RETERR) {
868 return XFS_ERROR(EINVAL);
870 xfs_fs_cmn_err(CE_WARN, mp,
871 "stripe alignment turned off: sunit(%d)/swidth(%d) incompatible with agsize(%d)",
872 mp->m_dalign, mp->m_swidth,
873 sbp->sb_agblocks);
875 mp->m_dalign = 0;
876 mp->m_swidth = 0;
877 } else if (mp->m_dalign) {
878 mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
879 } else {
880 if (mp->m_flags & XFS_MOUNT_RETERR) {
881 xfs_fs_cmn_err(CE_WARN, mp,
882 "stripe alignment turned off: sunit(%d) less than bsize(%d)",
883 mp->m_dalign,
884 mp->m_blockmask +1);
885 return XFS_ERROR(EINVAL);
887 mp->m_swidth = 0;
892 * Update superblock with new values
893 * and log changes
895 if (xfs_sb_version_hasdalign(sbp)) {
896 if (sbp->sb_unit != mp->m_dalign) {
897 sbp->sb_unit = mp->m_dalign;
898 mp->m_update_flags |= XFS_SB_UNIT;
900 if (sbp->sb_width != mp->m_swidth) {
901 sbp->sb_width = mp->m_swidth;
902 mp->m_update_flags |= XFS_SB_WIDTH;
905 } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
906 xfs_sb_version_hasdalign(&mp->m_sb)) {
907 mp->m_dalign = sbp->sb_unit;
908 mp->m_swidth = sbp->sb_width;
911 return 0;
915 * Set the maximum inode count for this filesystem
917 STATIC void
918 xfs_set_maxicount(xfs_mount_t *mp)
920 xfs_sb_t *sbp = &(mp->m_sb);
921 __uint64_t icount;
923 if (sbp->sb_imax_pct) {
925 * Make sure the maximum inode count is a multiple
926 * of the units we allocate inodes in.
928 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
929 do_div(icount, 100);
930 do_div(icount, mp->m_ialloc_blks);
931 mp->m_maxicount = (icount * mp->m_ialloc_blks) <<
932 sbp->sb_inopblog;
933 } else {
934 mp->m_maxicount = 0;
939 * Set the default minimum read and write sizes unless
940 * already specified in a mount option.
941 * We use smaller I/O sizes when the file system
942 * is being used for NFS service (wsync mount option).
944 STATIC void
945 xfs_set_rw_sizes(xfs_mount_t *mp)
947 xfs_sb_t *sbp = &(mp->m_sb);
948 int readio_log, writeio_log;
950 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
951 if (mp->m_flags & XFS_MOUNT_WSYNC) {
952 readio_log = XFS_WSYNC_READIO_LOG;
953 writeio_log = XFS_WSYNC_WRITEIO_LOG;
954 } else {
955 readio_log = XFS_READIO_LOG_LARGE;
956 writeio_log = XFS_WRITEIO_LOG_LARGE;
958 } else {
959 readio_log = mp->m_readio_log;
960 writeio_log = mp->m_writeio_log;
963 if (sbp->sb_blocklog > readio_log) {
964 mp->m_readio_log = sbp->sb_blocklog;
965 } else {
966 mp->m_readio_log = readio_log;
968 mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
969 if (sbp->sb_blocklog > writeio_log) {
970 mp->m_writeio_log = sbp->sb_blocklog;
971 } else {
972 mp->m_writeio_log = writeio_log;
974 mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
978 * precalculate the low space thresholds for dynamic speculative preallocation.
980 void
981 xfs_set_low_space_thresholds(
982 struct xfs_mount *mp)
984 int i;
986 for (i = 0; i < XFS_LOWSP_MAX; i++) {
987 __uint64_t space = mp->m_sb.sb_dblocks;
989 do_div(space, 100);
990 mp->m_low_space[i] = space * (i + 1);
996 * Set whether we're using inode alignment.
998 STATIC void
999 xfs_set_inoalignment(xfs_mount_t *mp)
1001 if (xfs_sb_version_hasalign(&mp->m_sb) &&
1002 mp->m_sb.sb_inoalignmt >=
1003 XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size))
1004 mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
1005 else
1006 mp->m_inoalign_mask = 0;
1008 * If we are using stripe alignment, check whether
1009 * the stripe unit is a multiple of the inode alignment
1011 if (mp->m_dalign && mp->m_inoalign_mask &&
1012 !(mp->m_dalign & mp->m_inoalign_mask))
1013 mp->m_sinoalign = mp->m_dalign;
1014 else
1015 mp->m_sinoalign = 0;
1019 * Check that the data (and log if separate) are an ok size.
1021 STATIC int
1022 xfs_check_sizes(xfs_mount_t *mp)
1024 xfs_buf_t *bp;
1025 xfs_daddr_t d;
1027 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
1028 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
1029 cmn_err(CE_WARN, "XFS: filesystem size mismatch detected");
1030 return XFS_ERROR(EFBIG);
1032 bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
1033 d - XFS_FSS_TO_BB(mp, 1),
1034 BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
1035 if (!bp) {
1036 cmn_err(CE_WARN, "XFS: last sector read failed");
1037 return EIO;
1039 xfs_buf_relse(bp);
1041 if (mp->m_logdev_targp != mp->m_ddev_targp) {
1042 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
1043 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
1044 cmn_err(CE_WARN, "XFS: log size mismatch detected");
1045 return XFS_ERROR(EFBIG);
1047 bp = xfs_buf_read_uncached(mp, mp->m_logdev_targp,
1048 d - XFS_FSB_TO_BB(mp, 1),
1049 XFS_FSB_TO_B(mp, 1), 0);
1050 if (!bp) {
1051 cmn_err(CE_WARN, "XFS: log device read failed");
1052 return EIO;
1054 xfs_buf_relse(bp);
1056 return 0;
1060 * Clear the quotaflags in memory and in the superblock.
1063 xfs_mount_reset_sbqflags(
1064 struct xfs_mount *mp)
1066 int error;
1067 struct xfs_trans *tp;
1069 mp->m_qflags = 0;
1072 * It is OK to look at sb_qflags here in mount path,
1073 * without m_sb_lock.
1075 if (mp->m_sb.sb_qflags == 0)
1076 return 0;
1077 spin_lock(&mp->m_sb_lock);
1078 mp->m_sb.sb_qflags = 0;
1079 spin_unlock(&mp->m_sb_lock);
1082 * If the fs is readonly, let the incore superblock run
1083 * with quotas off but don't flush the update out to disk
1085 if (mp->m_flags & XFS_MOUNT_RDONLY)
1086 return 0;
1088 #ifdef QUOTADEBUG
1089 xfs_fs_cmn_err(CE_NOTE, mp, "Writing superblock quota changes");
1090 #endif
1092 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
1093 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1094 XFS_DEFAULT_LOG_COUNT);
1095 if (error) {
1096 xfs_trans_cancel(tp, 0);
1097 xfs_fs_cmn_err(CE_ALERT, mp,
1098 "xfs_mount_reset_sbqflags: Superblock update failed!");
1099 return error;
1102 xfs_mod_sb(tp, XFS_SB_QFLAGS);
1103 return xfs_trans_commit(tp, 0);
1106 __uint64_t
1107 xfs_default_resblks(xfs_mount_t *mp)
1109 __uint64_t resblks;
1112 * We default to 5% or 8192 fsbs of space reserved, whichever is
1113 * smaller. This is intended to cover concurrent allocation
1114 * transactions when we initially hit enospc. These each require a 4
1115 * block reservation. Hence by default we cover roughly 2000 concurrent
1116 * allocation reservations.
1118 resblks = mp->m_sb.sb_dblocks;
1119 do_div(resblks, 20);
1120 resblks = min_t(__uint64_t, resblks, 8192);
1121 return resblks;
1125 * This function does the following on an initial mount of a file system:
1126 * - reads the superblock from disk and init the mount struct
1127 * - if we're a 32-bit kernel, do a size check on the superblock
1128 * so we don't mount terabyte filesystems
1129 * - init mount struct realtime fields
1130 * - allocate inode hash table for fs
1131 * - init directory manager
1132 * - perform recovery and init the log manager
1135 xfs_mountfs(
1136 xfs_mount_t *mp)
1138 xfs_sb_t *sbp = &(mp->m_sb);
1139 xfs_inode_t *rip;
1140 __uint64_t resblks;
1141 uint quotamount = 0;
1142 uint quotaflags = 0;
1143 int error = 0;
1145 xfs_mount_common(mp, sbp);
1148 * Check for a mismatched features2 values. Older kernels
1149 * read & wrote into the wrong sb offset for sb_features2
1150 * on some platforms due to xfs_sb_t not being 64bit size aligned
1151 * when sb_features2 was added, which made older superblock
1152 * reading/writing routines swap it as a 64-bit value.
1154 * For backwards compatibility, we make both slots equal.
1156 * If we detect a mismatched field, we OR the set bits into the
1157 * existing features2 field in case it has already been modified; we
1158 * don't want to lose any features. We then update the bad location
1159 * with the ORed value so that older kernels will see any features2
1160 * flags, and mark the two fields as needing updates once the
1161 * transaction subsystem is online.
1163 if (xfs_sb_has_mismatched_features2(sbp)) {
1164 cmn_err(CE_WARN,
1165 "XFS: correcting sb_features alignment problem");
1166 sbp->sb_features2 |= sbp->sb_bad_features2;
1167 sbp->sb_bad_features2 = sbp->sb_features2;
1168 mp->m_update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
1171 * Re-check for ATTR2 in case it was found in bad_features2
1172 * slot.
1174 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
1175 !(mp->m_flags & XFS_MOUNT_NOATTR2))
1176 mp->m_flags |= XFS_MOUNT_ATTR2;
1179 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
1180 (mp->m_flags & XFS_MOUNT_NOATTR2)) {
1181 xfs_sb_version_removeattr2(&mp->m_sb);
1182 mp->m_update_flags |= XFS_SB_FEATURES2;
1184 /* update sb_versionnum for the clearing of the morebits */
1185 if (!sbp->sb_features2)
1186 mp->m_update_flags |= XFS_SB_VERSIONNUM;
1190 * Check if sb_agblocks is aligned at stripe boundary
1191 * If sb_agblocks is NOT aligned turn off m_dalign since
1192 * allocator alignment is within an ag, therefore ag has
1193 * to be aligned at stripe boundary.
1195 error = xfs_update_alignment(mp);
1196 if (error)
1197 goto out;
1199 xfs_alloc_compute_maxlevels(mp);
1200 xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
1201 xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
1202 xfs_ialloc_compute_maxlevels(mp);
1204 xfs_set_maxicount(mp);
1206 mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog);
1208 error = xfs_uuid_mount(mp);
1209 if (error)
1210 goto out;
1213 * Set the minimum read and write sizes
1215 xfs_set_rw_sizes(mp);
1217 /* set the low space thresholds for dynamic preallocation */
1218 xfs_set_low_space_thresholds(mp);
1221 * Set the inode cluster size.
1222 * This may still be overridden by the file system
1223 * block size if it is larger than the chosen cluster size.
1225 mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
1228 * Set inode alignment fields
1230 xfs_set_inoalignment(mp);
1233 * Check that the data (and log if separate) are an ok size.
1235 error = xfs_check_sizes(mp);
1236 if (error)
1237 goto out_remove_uuid;
1240 * Initialize realtime fields in the mount structure
1242 error = xfs_rtmount_init(mp);
1243 if (error) {
1244 cmn_err(CE_WARN, "XFS: RT mount failed");
1245 goto out_remove_uuid;
1249 * Copies the low order bits of the timestamp and the randomly
1250 * set "sequence" number out of a UUID.
1252 uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
1254 mp->m_dmevmask = 0; /* not persistent; set after each mount */
1256 xfs_dir_mount(mp);
1259 * Initialize the attribute manager's entries.
1261 mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100;
1264 * Initialize the precomputed transaction reservations values.
1266 xfs_trans_init(mp);
1269 * Allocate and initialize the per-ag data.
1271 spin_lock_init(&mp->m_perag_lock);
1272 INIT_RADIX_TREE(&mp->m_perag_tree, GFP_ATOMIC);
1273 error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
1274 if (error) {
1275 cmn_err(CE_WARN, "XFS: Failed per-ag init: %d", error);
1276 goto out_remove_uuid;
1279 if (!sbp->sb_logblocks) {
1280 cmn_err(CE_WARN, "XFS: no log defined");
1281 XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
1282 error = XFS_ERROR(EFSCORRUPTED);
1283 goto out_free_perag;
1287 * log's mount-time initialization. Perform 1st part recovery if needed
1289 error = xfs_log_mount(mp, mp->m_logdev_targp,
1290 XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
1291 XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
1292 if (error) {
1293 cmn_err(CE_WARN, "XFS: log mount failed");
1294 goto out_free_perag;
1298 * Now the log is mounted, we know if it was an unclean shutdown or
1299 * not. If it was, with the first phase of recovery has completed, we
1300 * have consistent AG blocks on disk. We have not recovered EFIs yet,
1301 * but they are recovered transactionally in the second recovery phase
1302 * later.
1304 * Hence we can safely re-initialise incore superblock counters from
1305 * the per-ag data. These may not be correct if the filesystem was not
1306 * cleanly unmounted, so we need to wait for recovery to finish before
1307 * doing this.
1309 * If the filesystem was cleanly unmounted, then we can trust the
1310 * values in the superblock to be correct and we don't need to do
1311 * anything here.
1313 * If we are currently making the filesystem, the initialisation will
1314 * fail as the perag data is in an undefined state.
1316 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
1317 !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
1318 !mp->m_sb.sb_inprogress) {
1319 error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
1320 if (error)
1321 goto out_free_perag;
1325 * Get and sanity-check the root inode.
1326 * Save the pointer to it in the mount structure.
1328 error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip);
1329 if (error) {
1330 cmn_err(CE_WARN, "XFS: failed to read root inode");
1331 goto out_log_dealloc;
1334 ASSERT(rip != NULL);
1336 if (unlikely((rip->i_d.di_mode & S_IFMT) != S_IFDIR)) {
1337 cmn_err(CE_WARN, "XFS: corrupted root inode");
1338 cmn_err(CE_WARN, "Device %s - root %llu is not a directory",
1339 XFS_BUFTARG_NAME(mp->m_ddev_targp),
1340 (unsigned long long)rip->i_ino);
1341 xfs_iunlock(rip, XFS_ILOCK_EXCL);
1342 XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
1343 mp);
1344 error = XFS_ERROR(EFSCORRUPTED);
1345 goto out_rele_rip;
1347 mp->m_rootip = rip; /* save it */
1349 xfs_iunlock(rip, XFS_ILOCK_EXCL);
1352 * Initialize realtime inode pointers in the mount structure
1354 error = xfs_rtmount_inodes(mp);
1355 if (error) {
1357 * Free up the root inode.
1359 cmn_err(CE_WARN, "XFS: failed to read RT inodes");
1360 goto out_rele_rip;
1364 * If this is a read-only mount defer the superblock updates until
1365 * the next remount into writeable mode. Otherwise we would never
1366 * perform the update e.g. for the root filesystem.
1368 if (mp->m_update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
1369 error = xfs_mount_log_sb(mp, mp->m_update_flags);
1370 if (error) {
1371 cmn_err(CE_WARN, "XFS: failed to write sb changes");
1372 goto out_rtunmount;
1377 * Initialise the XFS quota management subsystem for this mount
1379 if (XFS_IS_QUOTA_RUNNING(mp)) {
1380 error = xfs_qm_newmount(mp, &quotamount, &quotaflags);
1381 if (error)
1382 goto out_rtunmount;
1383 } else {
1384 ASSERT(!XFS_IS_QUOTA_ON(mp));
1387 * If a file system had quotas running earlier, but decided to
1388 * mount without -o uquota/pquota/gquota options, revoke the
1389 * quotachecked license.
1391 if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
1392 cmn_err(CE_NOTE,
1393 "XFS: resetting qflags for filesystem %s",
1394 mp->m_fsname);
1396 error = xfs_mount_reset_sbqflags(mp);
1397 if (error)
1398 return error;
1403 * Finish recovering the file system. This part needed to be
1404 * delayed until after the root and real-time bitmap inodes
1405 * were consistently read in.
1407 error = xfs_log_mount_finish(mp);
1408 if (error) {
1409 cmn_err(CE_WARN, "XFS: log mount finish failed");
1410 goto out_rtunmount;
1414 * Complete the quota initialisation, post-log-replay component.
1416 if (quotamount) {
1417 ASSERT(mp->m_qflags == 0);
1418 mp->m_qflags = quotaflags;
1420 xfs_qm_mount_quotas(mp);
1424 * Now we are mounted, reserve a small amount of unused space for
1425 * privileged transactions. This is needed so that transaction
1426 * space required for critical operations can dip into this pool
1427 * when at ENOSPC. This is needed for operations like create with
1428 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
1429 * are not allowed to use this reserved space.
1431 * This may drive us straight to ENOSPC on mount, but that implies
1432 * we were already there on the last unmount. Warn if this occurs.
1434 if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
1435 resblks = xfs_default_resblks(mp);
1436 error = xfs_reserve_blocks(mp, &resblks, NULL);
1437 if (error)
1438 cmn_err(CE_WARN, "XFS: Unable to allocate reserve "
1439 "blocks. Continuing without a reserve pool.");
1442 return 0;
1444 out_rtunmount:
1445 xfs_rtunmount_inodes(mp);
1446 out_rele_rip:
1447 IRELE(rip);
1448 out_log_dealloc:
1449 xfs_log_unmount(mp);
1450 out_free_perag:
1451 xfs_free_perag(mp);
1452 out_remove_uuid:
1453 xfs_uuid_unmount(mp);
1454 out:
1455 return error;
1459 * This flushes out the inodes,dquots and the superblock, unmounts the
1460 * log and makes sure that incore structures are freed.
1462 void
1463 xfs_unmountfs(
1464 struct xfs_mount *mp)
1466 __uint64_t resblks;
1467 int error;
1469 xfs_qm_unmount_quotas(mp);
1470 xfs_rtunmount_inodes(mp);
1471 IRELE(mp->m_rootip);
1474 * We can potentially deadlock here if we have an inode cluster
1475 * that has been freed has its buffer still pinned in memory because
1476 * the transaction is still sitting in a iclog. The stale inodes
1477 * on that buffer will have their flush locks held until the
1478 * transaction hits the disk and the callbacks run. the inode
1479 * flush takes the flush lock unconditionally and with nothing to
1480 * push out the iclog we will never get that unlocked. hence we
1481 * need to force the log first.
1483 xfs_log_force(mp, XFS_LOG_SYNC);
1486 * Do a delwri reclaim pass first so that as many dirty inodes are
1487 * queued up for IO as possible. Then flush the buffers before making
1488 * a synchronous path to catch all the remaining inodes are reclaimed.
1489 * This makes the reclaim process as quick as possible by avoiding
1490 * synchronous writeout and blocking on inodes already in the delwri
1491 * state as much as possible.
1493 xfs_reclaim_inodes(mp, 0);
1494 XFS_bflush(mp->m_ddev_targp);
1495 xfs_reclaim_inodes(mp, SYNC_WAIT);
1497 xfs_qm_unmount(mp);
1500 * Flush out the log synchronously so that we know for sure
1501 * that nothing is pinned. This is important because bflush()
1502 * will skip pinned buffers.
1504 xfs_log_force(mp, XFS_LOG_SYNC);
1506 xfs_binval(mp->m_ddev_targp);
1507 if (mp->m_rtdev_targp) {
1508 xfs_binval(mp->m_rtdev_targp);
1512 * Unreserve any blocks we have so that when we unmount we don't account
1513 * the reserved free space as used. This is really only necessary for
1514 * lazy superblock counting because it trusts the incore superblock
1515 * counters to be absolutely correct on clean unmount.
1517 * We don't bother correcting this elsewhere for lazy superblock
1518 * counting because on mount of an unclean filesystem we reconstruct the
1519 * correct counter value and this is irrelevant.
1521 * For non-lazy counter filesystems, this doesn't matter at all because
1522 * we only every apply deltas to the superblock and hence the incore
1523 * value does not matter....
1525 resblks = 0;
1526 error = xfs_reserve_blocks(mp, &resblks, NULL);
1527 if (error)
1528 cmn_err(CE_WARN, "XFS: Unable to free reserved block pool. "
1529 "Freespace may not be correct on next mount.");
1531 error = xfs_log_sbcount(mp, 1);
1532 if (error)
1533 cmn_err(CE_WARN, "XFS: Unable to update superblock counters. "
1534 "Freespace may not be correct on next mount.");
1535 xfs_unmountfs_writesb(mp);
1536 xfs_unmountfs_wait(mp); /* wait for async bufs */
1537 xfs_log_unmount_write(mp);
1538 xfs_log_unmount(mp);
1539 xfs_uuid_unmount(mp);
1541 #if defined(DEBUG)
1542 xfs_errortag_clearall(mp, 0);
1543 #endif
1544 xfs_free_perag(mp);
1547 STATIC void
1548 xfs_unmountfs_wait(xfs_mount_t *mp)
1550 if (mp->m_logdev_targp != mp->m_ddev_targp)
1551 xfs_wait_buftarg(mp->m_logdev_targp);
1552 if (mp->m_rtdev_targp)
1553 xfs_wait_buftarg(mp->m_rtdev_targp);
1554 xfs_wait_buftarg(mp->m_ddev_targp);
1558 xfs_fs_writable(xfs_mount_t *mp)
1560 return !(xfs_test_for_freeze(mp) || XFS_FORCED_SHUTDOWN(mp) ||
1561 (mp->m_flags & XFS_MOUNT_RDONLY));
1565 * xfs_log_sbcount
1567 * Called either periodically to keep the on disk superblock values
1568 * roughly up to date or from unmount to make sure the values are
1569 * correct on a clean unmount.
1571 * Note this code can be called during the process of freezing, so
1572 * we may need to use the transaction allocator which does not not
1573 * block when the transaction subsystem is in its frozen state.
1576 xfs_log_sbcount(
1577 xfs_mount_t *mp,
1578 uint sync)
1580 xfs_trans_t *tp;
1581 int error;
1583 if (!xfs_fs_writable(mp))
1584 return 0;
1586 xfs_icsb_sync_counters(mp, 0);
1589 * we don't need to do this if we are updating the superblock
1590 * counters on every modification.
1592 if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
1593 return 0;
1595 tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);
1596 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1597 XFS_DEFAULT_LOG_COUNT);
1598 if (error) {
1599 xfs_trans_cancel(tp, 0);
1600 return error;
1603 xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
1604 if (sync)
1605 xfs_trans_set_sync(tp);
1606 error = xfs_trans_commit(tp, 0);
1607 return error;
1611 xfs_unmountfs_writesb(xfs_mount_t *mp)
1613 xfs_buf_t *sbp;
1614 int error = 0;
1617 * skip superblock write if fs is read-only, or
1618 * if we are doing a forced umount.
1620 if (!((mp->m_flags & XFS_MOUNT_RDONLY) ||
1621 XFS_FORCED_SHUTDOWN(mp))) {
1623 sbp = xfs_getsb(mp, 0);
1625 XFS_BUF_UNDONE(sbp);
1626 XFS_BUF_UNREAD(sbp);
1627 XFS_BUF_UNDELAYWRITE(sbp);
1628 XFS_BUF_WRITE(sbp);
1629 XFS_BUF_UNASYNC(sbp);
1630 ASSERT(XFS_BUF_TARGET(sbp) == mp->m_ddev_targp);
1631 xfsbdstrat(mp, sbp);
1632 error = xfs_buf_iowait(sbp);
1633 if (error)
1634 xfs_ioerror_alert("xfs_unmountfs_writesb",
1635 mp, sbp, XFS_BUF_ADDR(sbp));
1636 xfs_buf_relse(sbp);
1638 return error;
1642 * xfs_mod_sb() can be used to copy arbitrary changes to the
1643 * in-core superblock into the superblock buffer to be logged.
1644 * It does not provide the higher level of locking that is
1645 * needed to protect the in-core superblock from concurrent
1646 * access.
1648 void
1649 xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
1651 xfs_buf_t *bp;
1652 int first;
1653 int last;
1654 xfs_mount_t *mp;
1655 xfs_sb_field_t f;
1657 ASSERT(fields);
1658 if (!fields)
1659 return;
1660 mp = tp->t_mountp;
1661 bp = xfs_trans_getsb(tp, mp, 0);
1662 first = sizeof(xfs_sb_t);
1663 last = 0;
1665 /* translate/copy */
1667 xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
1669 /* find modified range */
1670 f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
1671 ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1672 last = xfs_sb_info[f + 1].offset - 1;
1674 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
1675 ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1676 first = xfs_sb_info[f].offset;
1678 xfs_trans_log_buf(tp, bp, first, last);
1683 * xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
1684 * a delta to a specified field in the in-core superblock. Simply
1685 * switch on the field indicated and apply the delta to that field.
1686 * Fields are not allowed to dip below zero, so if the delta would
1687 * do this do not apply it and return EINVAL.
1689 * The m_sb_lock must be held when this routine is called.
1691 STATIC int
1692 xfs_mod_incore_sb_unlocked(
1693 xfs_mount_t *mp,
1694 xfs_sb_field_t field,
1695 int64_t delta,
1696 int rsvd)
1698 int scounter; /* short counter for 32 bit fields */
1699 long long lcounter; /* long counter for 64 bit fields */
1700 long long res_used, rem;
1703 * With the in-core superblock spin lock held, switch
1704 * on the indicated field. Apply the delta to the
1705 * proper field. If the fields value would dip below
1706 * 0, then do not apply the delta and return EINVAL.
1708 switch (field) {
1709 case XFS_SBS_ICOUNT:
1710 lcounter = (long long)mp->m_sb.sb_icount;
1711 lcounter += delta;
1712 if (lcounter < 0) {
1713 ASSERT(0);
1714 return XFS_ERROR(EINVAL);
1716 mp->m_sb.sb_icount = lcounter;
1717 return 0;
1718 case XFS_SBS_IFREE:
1719 lcounter = (long long)mp->m_sb.sb_ifree;
1720 lcounter += delta;
1721 if (lcounter < 0) {
1722 ASSERT(0);
1723 return XFS_ERROR(EINVAL);
1725 mp->m_sb.sb_ifree = lcounter;
1726 return 0;
1727 case XFS_SBS_FDBLOCKS:
1728 lcounter = (long long)
1729 mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
1730 res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
1732 if (delta > 0) { /* Putting blocks back */
1733 if (res_used > delta) {
1734 mp->m_resblks_avail += delta;
1735 } else {
1736 rem = delta - res_used;
1737 mp->m_resblks_avail = mp->m_resblks;
1738 lcounter += rem;
1740 } else { /* Taking blocks away */
1741 lcounter += delta;
1742 if (lcounter >= 0) {
1743 mp->m_sb.sb_fdblocks = lcounter +
1744 XFS_ALLOC_SET_ASIDE(mp);
1745 return 0;
1749 * We are out of blocks, use any available reserved
1750 * blocks if were allowed to.
1752 if (!rsvd)
1753 return XFS_ERROR(ENOSPC);
1755 lcounter = (long long)mp->m_resblks_avail + delta;
1756 if (lcounter >= 0) {
1757 mp->m_resblks_avail = lcounter;
1758 return 0;
1760 printk_once(KERN_WARNING
1761 "Filesystem \"%s\": reserve blocks depleted! "
1762 "Consider increasing reserve pool size.",
1763 mp->m_fsname);
1764 return XFS_ERROR(ENOSPC);
1767 mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
1768 return 0;
1769 case XFS_SBS_FREXTENTS:
1770 lcounter = (long long)mp->m_sb.sb_frextents;
1771 lcounter += delta;
1772 if (lcounter < 0) {
1773 return XFS_ERROR(ENOSPC);
1775 mp->m_sb.sb_frextents = lcounter;
1776 return 0;
1777 case XFS_SBS_DBLOCKS:
1778 lcounter = (long long)mp->m_sb.sb_dblocks;
1779 lcounter += delta;
1780 if (lcounter < 0) {
1781 ASSERT(0);
1782 return XFS_ERROR(EINVAL);
1784 mp->m_sb.sb_dblocks = lcounter;
1785 return 0;
1786 case XFS_SBS_AGCOUNT:
1787 scounter = mp->m_sb.sb_agcount;
1788 scounter += delta;
1789 if (scounter < 0) {
1790 ASSERT(0);
1791 return XFS_ERROR(EINVAL);
1793 mp->m_sb.sb_agcount = scounter;
1794 return 0;
1795 case XFS_SBS_IMAX_PCT:
1796 scounter = mp->m_sb.sb_imax_pct;
1797 scounter += delta;
1798 if (scounter < 0) {
1799 ASSERT(0);
1800 return XFS_ERROR(EINVAL);
1802 mp->m_sb.sb_imax_pct = scounter;
1803 return 0;
1804 case XFS_SBS_REXTSIZE:
1805 scounter = mp->m_sb.sb_rextsize;
1806 scounter += delta;
1807 if (scounter < 0) {
1808 ASSERT(0);
1809 return XFS_ERROR(EINVAL);
1811 mp->m_sb.sb_rextsize = scounter;
1812 return 0;
1813 case XFS_SBS_RBMBLOCKS:
1814 scounter = mp->m_sb.sb_rbmblocks;
1815 scounter += delta;
1816 if (scounter < 0) {
1817 ASSERT(0);
1818 return XFS_ERROR(EINVAL);
1820 mp->m_sb.sb_rbmblocks = scounter;
1821 return 0;
1822 case XFS_SBS_RBLOCKS:
1823 lcounter = (long long)mp->m_sb.sb_rblocks;
1824 lcounter += delta;
1825 if (lcounter < 0) {
1826 ASSERT(0);
1827 return XFS_ERROR(EINVAL);
1829 mp->m_sb.sb_rblocks = lcounter;
1830 return 0;
1831 case XFS_SBS_REXTENTS:
1832 lcounter = (long long)mp->m_sb.sb_rextents;
1833 lcounter += delta;
1834 if (lcounter < 0) {
1835 ASSERT(0);
1836 return XFS_ERROR(EINVAL);
1838 mp->m_sb.sb_rextents = lcounter;
1839 return 0;
1840 case XFS_SBS_REXTSLOG:
1841 scounter = mp->m_sb.sb_rextslog;
1842 scounter += delta;
1843 if (scounter < 0) {
1844 ASSERT(0);
1845 return XFS_ERROR(EINVAL);
1847 mp->m_sb.sb_rextslog = scounter;
1848 return 0;
1849 default:
1850 ASSERT(0);
1851 return XFS_ERROR(EINVAL);
1856 * xfs_mod_incore_sb() is used to change a field in the in-core
1857 * superblock structure by the specified delta. This modification
1858 * is protected by the m_sb_lock. Just use the xfs_mod_incore_sb_unlocked()
1859 * routine to do the work.
1862 xfs_mod_incore_sb(
1863 struct xfs_mount *mp,
1864 xfs_sb_field_t field,
1865 int64_t delta,
1866 int rsvd)
1868 int status;
1870 #ifdef HAVE_PERCPU_SB
1871 ASSERT(field < XFS_SBS_ICOUNT || field > XFS_SBS_FDBLOCKS);
1872 #endif
1873 spin_lock(&mp->m_sb_lock);
1874 status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
1875 spin_unlock(&mp->m_sb_lock);
1877 return status;
1881 * Change more than one field in the in-core superblock structure at a time.
1883 * The fields and changes to those fields are specified in the array of
1884 * xfs_mod_sb structures passed in. Either all of the specified deltas
1885 * will be applied or none of them will. If any modified field dips below 0,
1886 * then all modifications will be backed out and EINVAL will be returned.
1888 * Note that this function may not be used for the superblock values that
1889 * are tracked with the in-memory per-cpu counters - a direct call to
1890 * xfs_icsb_modify_counters is required for these.
1893 xfs_mod_incore_sb_batch(
1894 struct xfs_mount *mp,
1895 xfs_mod_sb_t *msb,
1896 uint nmsb,
1897 int rsvd)
1899 xfs_mod_sb_t *msbp = &msb[0];
1900 int error = 0;
1903 * Loop through the array of mod structures and apply each individually.
1904 * If any fail, then back out all those which have already been applied.
1905 * Do all of this within the scope of the m_sb_lock so that all of the
1906 * changes will be atomic.
1908 spin_lock(&mp->m_sb_lock);
1909 for (msbp = &msbp[0]; msbp < (msb + nmsb); msbp++) {
1910 ASSERT(msbp->msb_field < XFS_SBS_ICOUNT ||
1911 msbp->msb_field > XFS_SBS_FDBLOCKS);
1913 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1914 msbp->msb_delta, rsvd);
1915 if (error)
1916 goto unwind;
1918 spin_unlock(&mp->m_sb_lock);
1919 return 0;
1921 unwind:
1922 while (--msbp >= msb) {
1923 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1924 -msbp->msb_delta, rsvd);
1925 ASSERT(error == 0);
1927 spin_unlock(&mp->m_sb_lock);
1928 return error;
1932 * xfs_getsb() is called to obtain the buffer for the superblock.
1933 * The buffer is returned locked and read in from disk.
1934 * The buffer should be released with a call to xfs_brelse().
1936 * If the flags parameter is BUF_TRYLOCK, then we'll only return
1937 * the superblock buffer if it can be locked without sleeping.
1938 * If it can't then we'll return NULL.
1940 xfs_buf_t *
1941 xfs_getsb(
1942 xfs_mount_t *mp,
1943 int flags)
1945 xfs_buf_t *bp;
1947 ASSERT(mp->m_sb_bp != NULL);
1948 bp = mp->m_sb_bp;
1949 if (flags & XBF_TRYLOCK) {
1950 if (!XFS_BUF_CPSEMA(bp)) {
1951 return NULL;
1953 } else {
1954 XFS_BUF_PSEMA(bp, PRIBIO);
1956 XFS_BUF_HOLD(bp);
1957 ASSERT(XFS_BUF_ISDONE(bp));
1958 return bp;
1962 * Used to free the superblock along various error paths.
1964 void
1965 xfs_freesb(
1966 struct xfs_mount *mp)
1968 struct xfs_buf *bp = mp->m_sb_bp;
1970 xfs_buf_lock(bp);
1971 mp->m_sb_bp = NULL;
1972 xfs_buf_relse(bp);
1976 * Used to log changes to the superblock unit and width fields which could
1977 * be altered by the mount options, as well as any potential sb_features2
1978 * fixup. Only the first superblock is updated.
1981 xfs_mount_log_sb(
1982 xfs_mount_t *mp,
1983 __int64_t fields)
1985 xfs_trans_t *tp;
1986 int error;
1988 ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
1989 XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2 |
1990 XFS_SB_VERSIONNUM));
1992 tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
1993 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1994 XFS_DEFAULT_LOG_COUNT);
1995 if (error) {
1996 xfs_trans_cancel(tp, 0);
1997 return error;
1999 xfs_mod_sb(tp, fields);
2000 error = xfs_trans_commit(tp, 0);
2001 return error;
2005 * If the underlying (data/log/rt) device is readonly, there are some
2006 * operations that cannot proceed.
2009 xfs_dev_is_read_only(
2010 struct xfs_mount *mp,
2011 char *message)
2013 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
2014 xfs_readonly_buftarg(mp->m_logdev_targp) ||
2015 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
2016 cmn_err(CE_NOTE,
2017 "XFS: %s required on read-only device.", message);
2018 cmn_err(CE_NOTE,
2019 "XFS: write access unavailable, cannot proceed.");
2020 return EROFS;
2022 return 0;
2025 #ifdef HAVE_PERCPU_SB
2027 * Per-cpu incore superblock counters
2029 * Simple concept, difficult implementation
2031 * Basically, replace the incore superblock counters with a distributed per cpu
2032 * counter for contended fields (e.g. free block count).
2034 * Difficulties arise in that the incore sb is used for ENOSPC checking, and
2035 * hence needs to be accurately read when we are running low on space. Hence
2036 * there is a method to enable and disable the per-cpu counters based on how
2037 * much "stuff" is available in them.
2039 * Basically, a counter is enabled if there is enough free resource to justify
2040 * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
2041 * ENOSPC), then we disable the counters to synchronise all callers and
2042 * re-distribute the available resources.
2044 * If, once we redistributed the available resources, we still get a failure,
2045 * we disable the per-cpu counter and go through the slow path.
2047 * The slow path is the current xfs_mod_incore_sb() function. This means that
2048 * when we disable a per-cpu counter, we need to drain its resources back to
2049 * the global superblock. We do this after disabling the counter to prevent
2050 * more threads from queueing up on the counter.
2052 * Essentially, this means that we still need a lock in the fast path to enable
2053 * synchronisation between the global counters and the per-cpu counters. This
2054 * is not a problem because the lock will be local to a CPU almost all the time
2055 * and have little contention except when we get to ENOSPC conditions.
2057 * Basically, this lock becomes a barrier that enables us to lock out the fast
2058 * path while we do things like enabling and disabling counters and
2059 * synchronising the counters.
2061 * Locking rules:
2063 * 1. m_sb_lock before picking up per-cpu locks
2064 * 2. per-cpu locks always picked up via for_each_online_cpu() order
2065 * 3. accurate counter sync requires m_sb_lock + per cpu locks
2066 * 4. modifying per-cpu counters requires holding per-cpu lock
2067 * 5. modifying global counters requires holding m_sb_lock
2068 * 6. enabling or disabling a counter requires holding the m_sb_lock
2069 * and _none_ of the per-cpu locks.
2071 * Disabled counters are only ever re-enabled by a balance operation
2072 * that results in more free resources per CPU than a given threshold.
2073 * To ensure counters don't remain disabled, they are rebalanced when
2074 * the global resource goes above a higher threshold (i.e. some hysteresis
2075 * is present to prevent thrashing).
2078 #ifdef CONFIG_HOTPLUG_CPU
2080 * hot-plug CPU notifier support.
2082 * We need a notifier per filesystem as we need to be able to identify
2083 * the filesystem to balance the counters out. This is achieved by
2084 * having a notifier block embedded in the xfs_mount_t and doing pointer
2085 * magic to get the mount pointer from the notifier block address.
2087 STATIC int
2088 xfs_icsb_cpu_notify(
2089 struct notifier_block *nfb,
2090 unsigned long action,
2091 void *hcpu)
2093 xfs_icsb_cnts_t *cntp;
2094 xfs_mount_t *mp;
2096 mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
2097 cntp = (xfs_icsb_cnts_t *)
2098 per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
2099 switch (action) {
2100 case CPU_UP_PREPARE:
2101 case CPU_UP_PREPARE_FROZEN:
2102 /* Easy Case - initialize the area and locks, and
2103 * then rebalance when online does everything else for us. */
2104 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2105 break;
2106 case CPU_ONLINE:
2107 case CPU_ONLINE_FROZEN:
2108 xfs_icsb_lock(mp);
2109 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
2110 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
2111 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
2112 xfs_icsb_unlock(mp);
2113 break;
2114 case CPU_DEAD:
2115 case CPU_DEAD_FROZEN:
2116 /* Disable all the counters, then fold the dead cpu's
2117 * count into the total on the global superblock and
2118 * re-enable the counters. */
2119 xfs_icsb_lock(mp);
2120 spin_lock(&mp->m_sb_lock);
2121 xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
2122 xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
2123 xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
2125 mp->m_sb.sb_icount += cntp->icsb_icount;
2126 mp->m_sb.sb_ifree += cntp->icsb_ifree;
2127 mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
2129 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2131 xfs_icsb_balance_counter_locked(mp, XFS_SBS_ICOUNT, 0);
2132 xfs_icsb_balance_counter_locked(mp, XFS_SBS_IFREE, 0);
2133 xfs_icsb_balance_counter_locked(mp, XFS_SBS_FDBLOCKS, 0);
2134 spin_unlock(&mp->m_sb_lock);
2135 xfs_icsb_unlock(mp);
2136 break;
2139 return NOTIFY_OK;
2141 #endif /* CONFIG_HOTPLUG_CPU */
2144 xfs_icsb_init_counters(
2145 xfs_mount_t *mp)
2147 xfs_icsb_cnts_t *cntp;
2148 int i;
2150 mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
2151 if (mp->m_sb_cnts == NULL)
2152 return -ENOMEM;
2154 #ifdef CONFIG_HOTPLUG_CPU
2155 mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
2156 mp->m_icsb_notifier.priority = 0;
2157 register_hotcpu_notifier(&mp->m_icsb_notifier);
2158 #endif /* CONFIG_HOTPLUG_CPU */
2160 for_each_online_cpu(i) {
2161 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2162 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2165 mutex_init(&mp->m_icsb_mutex);
2168 * start with all counters disabled so that the
2169 * initial balance kicks us off correctly
2171 mp->m_icsb_counters = -1;
2172 return 0;
2175 void
2176 xfs_icsb_reinit_counters(
2177 xfs_mount_t *mp)
2179 xfs_icsb_lock(mp);
2181 * start with all counters disabled so that the
2182 * initial balance kicks us off correctly
2184 mp->m_icsb_counters = -1;
2185 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
2186 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
2187 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
2188 xfs_icsb_unlock(mp);
2191 void
2192 xfs_icsb_destroy_counters(
2193 xfs_mount_t *mp)
2195 if (mp->m_sb_cnts) {
2196 unregister_hotcpu_notifier(&mp->m_icsb_notifier);
2197 free_percpu(mp->m_sb_cnts);
2199 mutex_destroy(&mp->m_icsb_mutex);
2202 STATIC void
2203 xfs_icsb_lock_cntr(
2204 xfs_icsb_cnts_t *icsbp)
2206 while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
2207 ndelay(1000);
2211 STATIC void
2212 xfs_icsb_unlock_cntr(
2213 xfs_icsb_cnts_t *icsbp)
2215 clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
2219 STATIC void
2220 xfs_icsb_lock_all_counters(
2221 xfs_mount_t *mp)
2223 xfs_icsb_cnts_t *cntp;
2224 int i;
2226 for_each_online_cpu(i) {
2227 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2228 xfs_icsb_lock_cntr(cntp);
2232 STATIC void
2233 xfs_icsb_unlock_all_counters(
2234 xfs_mount_t *mp)
2236 xfs_icsb_cnts_t *cntp;
2237 int i;
2239 for_each_online_cpu(i) {
2240 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2241 xfs_icsb_unlock_cntr(cntp);
2245 STATIC void
2246 xfs_icsb_count(
2247 xfs_mount_t *mp,
2248 xfs_icsb_cnts_t *cnt,
2249 int flags)
2251 xfs_icsb_cnts_t *cntp;
2252 int i;
2254 memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
2256 if (!(flags & XFS_ICSB_LAZY_COUNT))
2257 xfs_icsb_lock_all_counters(mp);
2259 for_each_online_cpu(i) {
2260 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2261 cnt->icsb_icount += cntp->icsb_icount;
2262 cnt->icsb_ifree += cntp->icsb_ifree;
2263 cnt->icsb_fdblocks += cntp->icsb_fdblocks;
2266 if (!(flags & XFS_ICSB_LAZY_COUNT))
2267 xfs_icsb_unlock_all_counters(mp);
2270 STATIC int
2271 xfs_icsb_counter_disabled(
2272 xfs_mount_t *mp,
2273 xfs_sb_field_t field)
2275 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2276 return test_bit(field, &mp->m_icsb_counters);
2279 STATIC void
2280 xfs_icsb_disable_counter(
2281 xfs_mount_t *mp,
2282 xfs_sb_field_t field)
2284 xfs_icsb_cnts_t cnt;
2286 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2289 * If we are already disabled, then there is nothing to do
2290 * here. We check before locking all the counters to avoid
2291 * the expensive lock operation when being called in the
2292 * slow path and the counter is already disabled. This is
2293 * safe because the only time we set or clear this state is under
2294 * the m_icsb_mutex.
2296 if (xfs_icsb_counter_disabled(mp, field))
2297 return;
2299 xfs_icsb_lock_all_counters(mp);
2300 if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
2301 /* drain back to superblock */
2303 xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
2304 switch(field) {
2305 case XFS_SBS_ICOUNT:
2306 mp->m_sb.sb_icount = cnt.icsb_icount;
2307 break;
2308 case XFS_SBS_IFREE:
2309 mp->m_sb.sb_ifree = cnt.icsb_ifree;
2310 break;
2311 case XFS_SBS_FDBLOCKS:
2312 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
2313 break;
2314 default:
2315 BUG();
2319 xfs_icsb_unlock_all_counters(mp);
2322 STATIC void
2323 xfs_icsb_enable_counter(
2324 xfs_mount_t *mp,
2325 xfs_sb_field_t field,
2326 uint64_t count,
2327 uint64_t resid)
2329 xfs_icsb_cnts_t *cntp;
2330 int i;
2332 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2334 xfs_icsb_lock_all_counters(mp);
2335 for_each_online_cpu(i) {
2336 cntp = per_cpu_ptr(mp->m_sb_cnts, i);
2337 switch (field) {
2338 case XFS_SBS_ICOUNT:
2339 cntp->icsb_icount = count + resid;
2340 break;
2341 case XFS_SBS_IFREE:
2342 cntp->icsb_ifree = count + resid;
2343 break;
2344 case XFS_SBS_FDBLOCKS:
2345 cntp->icsb_fdblocks = count + resid;
2346 break;
2347 default:
2348 BUG();
2349 break;
2351 resid = 0;
2353 clear_bit(field, &mp->m_icsb_counters);
2354 xfs_icsb_unlock_all_counters(mp);
2357 void
2358 xfs_icsb_sync_counters_locked(
2359 xfs_mount_t *mp,
2360 int flags)
2362 xfs_icsb_cnts_t cnt;
2364 xfs_icsb_count(mp, &cnt, flags);
2366 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
2367 mp->m_sb.sb_icount = cnt.icsb_icount;
2368 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
2369 mp->m_sb.sb_ifree = cnt.icsb_ifree;
2370 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
2371 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
2375 * Accurate update of per-cpu counters to incore superblock
2377 void
2378 xfs_icsb_sync_counters(
2379 xfs_mount_t *mp,
2380 int flags)
2382 spin_lock(&mp->m_sb_lock);
2383 xfs_icsb_sync_counters_locked(mp, flags);
2384 spin_unlock(&mp->m_sb_lock);
2388 * Balance and enable/disable counters as necessary.
2390 * Thresholds for re-enabling counters are somewhat magic. inode counts are
2391 * chosen to be the same number as single on disk allocation chunk per CPU, and
2392 * free blocks is something far enough zero that we aren't going thrash when we
2393 * get near ENOSPC. We also need to supply a minimum we require per cpu to
2394 * prevent looping endlessly when xfs_alloc_space asks for more than will
2395 * be distributed to a single CPU but each CPU has enough blocks to be
2396 * reenabled.
2398 * Note that we can be called when counters are already disabled.
2399 * xfs_icsb_disable_counter() optimises the counter locking in this case to
2400 * prevent locking every per-cpu counter needlessly.
2403 #define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
2404 #define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
2405 (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
2406 STATIC void
2407 xfs_icsb_balance_counter_locked(
2408 xfs_mount_t *mp,
2409 xfs_sb_field_t field,
2410 int min_per_cpu)
2412 uint64_t count, resid;
2413 int weight = num_online_cpus();
2414 uint64_t min = (uint64_t)min_per_cpu;
2416 /* disable counter and sync counter */
2417 xfs_icsb_disable_counter(mp, field);
2419 /* update counters - first CPU gets residual*/
2420 switch (field) {
2421 case XFS_SBS_ICOUNT:
2422 count = mp->m_sb.sb_icount;
2423 resid = do_div(count, weight);
2424 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
2425 return;
2426 break;
2427 case XFS_SBS_IFREE:
2428 count = mp->m_sb.sb_ifree;
2429 resid = do_div(count, weight);
2430 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
2431 return;
2432 break;
2433 case XFS_SBS_FDBLOCKS:
2434 count = mp->m_sb.sb_fdblocks;
2435 resid = do_div(count, weight);
2436 if (count < max(min, XFS_ICSB_FDBLK_CNTR_REENABLE(mp)))
2437 return;
2438 break;
2439 default:
2440 BUG();
2441 count = resid = 0; /* quiet, gcc */
2442 break;
2445 xfs_icsb_enable_counter(mp, field, count, resid);
2448 STATIC void
2449 xfs_icsb_balance_counter(
2450 xfs_mount_t *mp,
2451 xfs_sb_field_t fields,
2452 int min_per_cpu)
2454 spin_lock(&mp->m_sb_lock);
2455 xfs_icsb_balance_counter_locked(mp, fields, min_per_cpu);
2456 spin_unlock(&mp->m_sb_lock);
2460 xfs_icsb_modify_counters(
2461 xfs_mount_t *mp,
2462 xfs_sb_field_t field,
2463 int64_t delta,
2464 int rsvd)
2466 xfs_icsb_cnts_t *icsbp;
2467 long long lcounter; /* long counter for 64 bit fields */
2468 int ret = 0;
2470 might_sleep();
2471 again:
2472 preempt_disable();
2473 icsbp = this_cpu_ptr(mp->m_sb_cnts);
2476 * if the counter is disabled, go to slow path
2478 if (unlikely(xfs_icsb_counter_disabled(mp, field)))
2479 goto slow_path;
2480 xfs_icsb_lock_cntr(icsbp);
2481 if (unlikely(xfs_icsb_counter_disabled(mp, field))) {
2482 xfs_icsb_unlock_cntr(icsbp);
2483 goto slow_path;
2486 switch (field) {
2487 case XFS_SBS_ICOUNT:
2488 lcounter = icsbp->icsb_icount;
2489 lcounter += delta;
2490 if (unlikely(lcounter < 0))
2491 goto balance_counter;
2492 icsbp->icsb_icount = lcounter;
2493 break;
2495 case XFS_SBS_IFREE:
2496 lcounter = icsbp->icsb_ifree;
2497 lcounter += delta;
2498 if (unlikely(lcounter < 0))
2499 goto balance_counter;
2500 icsbp->icsb_ifree = lcounter;
2501 break;
2503 case XFS_SBS_FDBLOCKS:
2504 BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
2506 lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
2507 lcounter += delta;
2508 if (unlikely(lcounter < 0))
2509 goto balance_counter;
2510 icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
2511 break;
2512 default:
2513 BUG();
2514 break;
2516 xfs_icsb_unlock_cntr(icsbp);
2517 preempt_enable();
2518 return 0;
2520 slow_path:
2521 preempt_enable();
2524 * serialise with a mutex so we don't burn lots of cpu on
2525 * the superblock lock. We still need to hold the superblock
2526 * lock, however, when we modify the global structures.
2528 xfs_icsb_lock(mp);
2531 * Now running atomically.
2533 * If the counter is enabled, someone has beaten us to rebalancing.
2534 * Drop the lock and try again in the fast path....
2536 if (!(xfs_icsb_counter_disabled(mp, field))) {
2537 xfs_icsb_unlock(mp);
2538 goto again;
2542 * The counter is currently disabled. Because we are
2543 * running atomically here, we know a rebalance cannot
2544 * be in progress. Hence we can go straight to operating
2545 * on the global superblock. We do not call xfs_mod_incore_sb()
2546 * here even though we need to get the m_sb_lock. Doing so
2547 * will cause us to re-enter this function and deadlock.
2548 * Hence we get the m_sb_lock ourselves and then call
2549 * xfs_mod_incore_sb_unlocked() as the unlocked path operates
2550 * directly on the global counters.
2552 spin_lock(&mp->m_sb_lock);
2553 ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
2554 spin_unlock(&mp->m_sb_lock);
2557 * Now that we've modified the global superblock, we
2558 * may be able to re-enable the distributed counters
2559 * (e.g. lots of space just got freed). After that
2560 * we are done.
2562 if (ret != ENOSPC)
2563 xfs_icsb_balance_counter(mp, field, 0);
2564 xfs_icsb_unlock(mp);
2565 return ret;
2567 balance_counter:
2568 xfs_icsb_unlock_cntr(icsbp);
2569 preempt_enable();
2572 * We may have multiple threads here if multiple per-cpu
2573 * counters run dry at the same time. This will mean we can
2574 * do more balances than strictly necessary but it is not
2575 * the common slowpath case.
2577 xfs_icsb_lock(mp);
2580 * running atomically.
2582 * This will leave the counter in the correct state for future
2583 * accesses. After the rebalance, we simply try again and our retry
2584 * will either succeed through the fast path or slow path without
2585 * another balance operation being required.
2587 xfs_icsb_balance_counter(mp, field, delta);
2588 xfs_icsb_unlock(mp);
2589 goto again;
2592 #endif