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1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_shared.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_bit.h"
25#include "xfs_sb.h"
26#include "xfs_mount.h"
27#include "xfs_defer.h"
28#include "xfs_da_format.h"
29#include "xfs_da_btree.h"
30#include "xfs_inode.h"
31#include "xfs_dir2.h"
32#include "xfs_ialloc.h"
33#include "xfs_alloc.h"
34#include "xfs_rtalloc.h"
35#include "xfs_bmap.h"
36#include "xfs_trans.h"
37#include "xfs_trans_priv.h"
38#include "xfs_log.h"
39#include "xfs_error.h"
40#include "xfs_quota.h"
41#include "xfs_fsops.h"
42#include "xfs_trace.h"
43#include "xfs_icache.h"
44#include "xfs_sysfs.h"
45#include "xfs_rmap_btree.h"
46#include "xfs_refcount_btree.h"
47#include "xfs_reflink.h"
48#include "xfs_extent_busy.h"
49
50
51static DEFINE_MUTEX(xfs_uuid_table_mutex);
52static int xfs_uuid_table_size;
53static uuid_t *xfs_uuid_table;
54
55void
56xfs_uuid_table_free(void)
57{
58 if (xfs_uuid_table_size == 0)
59 return;
60 kmem_free(xfs_uuid_table);
61 xfs_uuid_table = NULL;
62 xfs_uuid_table_size = 0;
63}
64
65/*
66 * See if the UUID is unique among mounted XFS filesystems.
67 * Mount fails if UUID is nil or a FS with the same UUID is already mounted.
68 */
69STATIC int
70xfs_uuid_mount(
71 struct xfs_mount *mp)
72{
73 uuid_t *uuid = &mp->m_sb.sb_uuid;
74 int hole, i;
75
76 /* Publish UUID in struct super_block */
77 uuid_copy(&mp->m_super->s_uuid, uuid);
78
79 if (mp->m_flags & XFS_MOUNT_NOUUID)
80 return 0;
81
82 if (uuid_is_null(uuid)) {
83 xfs_warn(mp, "Filesystem has null UUID - can't mount");
84 return -EINVAL;
85 }
86
87 mutex_lock(&xfs_uuid_table_mutex);
88 for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
89 if (uuid_is_null(&xfs_uuid_table[i])) {
90 hole = i;
91 continue;
92 }
93 if (uuid_equal(uuid, &xfs_uuid_table[i]))
94 goto out_duplicate;
95 }
96
97 if (hole < 0) {
98 xfs_uuid_table = kmem_realloc(xfs_uuid_table,
99 (xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
100 KM_SLEEP);
101 hole = xfs_uuid_table_size++;
102 }
103 xfs_uuid_table[hole] = *uuid;
104 mutex_unlock(&xfs_uuid_table_mutex);
105
106 return 0;
107
108 out_duplicate:
109 mutex_unlock(&xfs_uuid_table_mutex);
110 xfs_warn(mp, "Filesystem has duplicate UUID %pU - can't mount", uuid);
111 return -EINVAL;
112}
113
114STATIC void
115xfs_uuid_unmount(
116 struct xfs_mount *mp)
117{
118 uuid_t *uuid = &mp->m_sb.sb_uuid;
119 int i;
120
121 if (mp->m_flags & XFS_MOUNT_NOUUID)
122 return;
123
124 mutex_lock(&xfs_uuid_table_mutex);
125 for (i = 0; i < xfs_uuid_table_size; i++) {
126 if (uuid_is_null(&xfs_uuid_table[i]))
127 continue;
128 if (!uuid_equal(uuid, &xfs_uuid_table[i]))
129 continue;
130 memset(&xfs_uuid_table[i], 0, sizeof(uuid_t));
131 break;
132 }
133 ASSERT(i < xfs_uuid_table_size);
134 mutex_unlock(&xfs_uuid_table_mutex);
135}
136
137
138STATIC void
139__xfs_free_perag(
140 struct rcu_head *head)
141{
142 struct xfs_perag *pag = container_of(head, struct xfs_perag, rcu_head);
143
144 ASSERT(atomic_read(&pag->pag_ref) == 0);
145 kmem_free(pag);
146}
147
148/*
149 * Free up the per-ag resources associated with the mount structure.
150 */
151STATIC void
152xfs_free_perag(
153 xfs_mount_t *mp)
154{
155 xfs_agnumber_t agno;
156 struct xfs_perag *pag;
157
158 for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
159 spin_lock(&mp->m_perag_lock);
160 pag = radix_tree_delete(&mp->m_perag_tree, agno);
161 spin_unlock(&mp->m_perag_lock);
162 ASSERT(pag);
163 ASSERT(atomic_read(&pag->pag_ref) == 0);
164 xfs_buf_hash_destroy(pag);
165 mutex_destroy(&pag->pag_ici_reclaim_lock);
166 call_rcu(&pag->rcu_head, __xfs_free_perag);
167 }
168}
169
170/*
171 * Check size of device based on the (data/realtime) block count.
172 * Note: this check is used by the growfs code as well as mount.
173 */
174int
175xfs_sb_validate_fsb_count(
176 xfs_sb_t *sbp,
177 uint64_t nblocks)
178{
179 ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
180 ASSERT(sbp->sb_blocklog >= BBSHIFT);
181
182 /* Limited by ULONG_MAX of page cache index */
183 if (nblocks >> (PAGE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
184 return -EFBIG;
185 return 0;
186}
187
188int
189xfs_initialize_perag(
190 xfs_mount_t *mp,
191 xfs_agnumber_t agcount,
192 xfs_agnumber_t *maxagi)
193{
194 xfs_agnumber_t index;
195 xfs_agnumber_t first_initialised = NULLAGNUMBER;
196 xfs_perag_t *pag;
197 int error = -ENOMEM;
198
199 /*
200 * Walk the current per-ag tree so we don't try to initialise AGs
201 * that already exist (growfs case). Allocate and insert all the
202 * AGs we don't find ready for initialisation.
203 */
204 for (index = 0; index < agcount; index++) {
205 pag = xfs_perag_get(mp, index);
206 if (pag) {
207 xfs_perag_put(pag);
208 continue;
209 }
210
211 pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
212 if (!pag)
213 goto out_unwind_new_pags;
214 pag->pag_agno = index;
215 pag->pag_mount = mp;
216 spin_lock_init(&pag->pag_ici_lock);
217 mutex_init(&pag->pag_ici_reclaim_lock);
218 INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
219 if (xfs_buf_hash_init(pag))
220 goto out_free_pag;
221 init_waitqueue_head(&pag->pagb_wait);
222
223 if (radix_tree_preload(GFP_NOFS))
224 goto out_hash_destroy;
225
226 spin_lock(&mp->m_perag_lock);
227 if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
228 BUG();
229 spin_unlock(&mp->m_perag_lock);
230 radix_tree_preload_end();
231 error = -EEXIST;
232 goto out_hash_destroy;
233 }
234 spin_unlock(&mp->m_perag_lock);
235 radix_tree_preload_end();
236 /* first new pag is fully initialized */
237 if (first_initialised == NULLAGNUMBER)
238 first_initialised = index;
239 }
240
241 index = xfs_set_inode_alloc(mp, agcount);
242
243 if (maxagi)
244 *maxagi = index;
245
246 mp->m_ag_prealloc_blocks = xfs_prealloc_blocks(mp);
247 return 0;
248
249out_hash_destroy:
250 xfs_buf_hash_destroy(pag);
251out_free_pag:
252 mutex_destroy(&pag->pag_ici_reclaim_lock);
253 kmem_free(pag);
254out_unwind_new_pags:
255 /* unwind any prior newly initialized pags */
256 for (index = first_initialised; index < agcount; index++) {
257 pag = radix_tree_delete(&mp->m_perag_tree, index);
258 if (!pag)
259 break;
260 xfs_buf_hash_destroy(pag);
261 mutex_destroy(&pag->pag_ici_reclaim_lock);
262 kmem_free(pag);
263 }
264 return error;
265}
266
267/*
268 * xfs_readsb
269 *
270 * Does the initial read of the superblock.
271 */
272int
273xfs_readsb(
274 struct xfs_mount *mp,
275 int flags)
276{
277 unsigned int sector_size;
278 struct xfs_buf *bp;
279 struct xfs_sb *sbp = &mp->m_sb;
280 int error;
281 int loud = !(flags & XFS_MFSI_QUIET);
282 const struct xfs_buf_ops *buf_ops;
283
284 ASSERT(mp->m_sb_bp == NULL);
285 ASSERT(mp->m_ddev_targp != NULL);
286
287 /*
288 * For the initial read, we must guess at the sector
289 * size based on the block device. It's enough to
290 * get the sb_sectsize out of the superblock and
291 * then reread with the proper length.
292 * We don't verify it yet, because it may not be complete.
293 */
294 sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
295 buf_ops = NULL;
296
297 /*
298 * Allocate a (locked) buffer to hold the superblock. This will be kept
299 * around at all times to optimize access to the superblock. Therefore,
300 * set XBF_NO_IOACCT to make sure it doesn't hold the buftarg count
301 * elevated.
302 */
303reread:
304 error = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR,
305 BTOBB(sector_size), XBF_NO_IOACCT, &bp,
306 buf_ops);
307 if (error) {
308 if (loud)
309 xfs_warn(mp, "SB validate failed with error %d.", error);
310 /* bad CRC means corrupted metadata */
311 if (error == -EFSBADCRC)
312 error = -EFSCORRUPTED;
313 return error;
314 }
315
316 /*
317 * Initialize the mount structure from the superblock.
318 */
319 xfs_sb_from_disk(sbp, XFS_BUF_TO_SBP(bp));
320
321 /*
322 * If we haven't validated the superblock, do so now before we try
323 * to check the sector size and reread the superblock appropriately.
324 */
325 if (sbp->sb_magicnum != XFS_SB_MAGIC) {
326 if (loud)
327 xfs_warn(mp, "Invalid superblock magic number");
328 error = -EINVAL;
329 goto release_buf;
330 }
331
332 /*
333 * We must be able to do sector-sized and sector-aligned IO.
334 */
335 if (sector_size > sbp->sb_sectsize) {
336 if (loud)
337 xfs_warn(mp, "device supports %u byte sectors (not %u)",
338 sector_size, sbp->sb_sectsize);
339 error = -ENOSYS;
340 goto release_buf;
341 }
342
343 if (buf_ops == NULL) {
344 /*
345 * Re-read the superblock so the buffer is correctly sized,
346 * and properly verified.
347 */
348 xfs_buf_relse(bp);
349 sector_size = sbp->sb_sectsize;
350 buf_ops = loud ? &xfs_sb_buf_ops : &xfs_sb_quiet_buf_ops;
351 goto reread;
352 }
353
354 xfs_reinit_percpu_counters(mp);
355
356 /* no need to be quiet anymore, so reset the buf ops */
357 bp->b_ops = &xfs_sb_buf_ops;
358
359 mp->m_sb_bp = bp;
360 xfs_buf_unlock(bp);
361 return 0;
362
363release_buf:
364 xfs_buf_relse(bp);
365 return error;
366}
367
368/*
369 * Update alignment values based on mount options and sb values
370 */
371STATIC int
372xfs_update_alignment(xfs_mount_t *mp)
373{
374 xfs_sb_t *sbp = &(mp->m_sb);
375
376 if (mp->m_dalign) {
377 /*
378 * If stripe unit and stripe width are not multiples
379 * of the fs blocksize turn off alignment.
380 */
381 if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
382 (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
383 xfs_warn(mp,
384 "alignment check failed: sunit/swidth vs. blocksize(%d)",
385 sbp->sb_blocksize);
386 return -EINVAL;
387 } else {
388 /*
389 * Convert the stripe unit and width to FSBs.
390 */
391 mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
392 if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
393 xfs_warn(mp,
394 "alignment check failed: sunit/swidth vs. agsize(%d)",
395 sbp->sb_agblocks);
396 return -EINVAL;
397 } else if (mp->m_dalign) {
398 mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
399 } else {
400 xfs_warn(mp,
401 "alignment check failed: sunit(%d) less than bsize(%d)",
402 mp->m_dalign, sbp->sb_blocksize);
403 return -EINVAL;
404 }
405 }
406
407 /*
408 * Update superblock with new values
409 * and log changes
410 */
411 if (xfs_sb_version_hasdalign(sbp)) {
412 if (sbp->sb_unit != mp->m_dalign) {
413 sbp->sb_unit = mp->m_dalign;
414 mp->m_update_sb = true;
415 }
416 if (sbp->sb_width != mp->m_swidth) {
417 sbp->sb_width = mp->m_swidth;
418 mp->m_update_sb = true;
419 }
420 } else {
421 xfs_warn(mp,
422 "cannot change alignment: superblock does not support data alignment");
423 return -EINVAL;
424 }
425 } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
426 xfs_sb_version_hasdalign(&mp->m_sb)) {
427 mp->m_dalign = sbp->sb_unit;
428 mp->m_swidth = sbp->sb_width;
429 }
430
431 return 0;
432}
433
434/*
435 * Set the maximum inode count for this filesystem
436 */
437STATIC void
438xfs_set_maxicount(xfs_mount_t *mp)
439{
440 xfs_sb_t *sbp = &(mp->m_sb);
441 uint64_t icount;
442
443 if (sbp->sb_imax_pct) {
444 /*
445 * Make sure the maximum inode count is a multiple
446 * of the units we allocate inodes in.
447 */
448 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
449 do_div(icount, 100);
450 do_div(icount, mp->m_ialloc_blks);
451 mp->m_maxicount = (icount * mp->m_ialloc_blks) <<
452 sbp->sb_inopblog;
453 } else {
454 mp->m_maxicount = 0;
455 }
456}
457
458/*
459 * Set the default minimum read and write sizes unless
460 * already specified in a mount option.
461 * We use smaller I/O sizes when the file system
462 * is being used for NFS service (wsync mount option).
463 */
464STATIC void
465xfs_set_rw_sizes(xfs_mount_t *mp)
466{
467 xfs_sb_t *sbp = &(mp->m_sb);
468 int readio_log, writeio_log;
469
470 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
471 if (mp->m_flags & XFS_MOUNT_WSYNC) {
472 readio_log = XFS_WSYNC_READIO_LOG;
473 writeio_log = XFS_WSYNC_WRITEIO_LOG;
474 } else {
475 readio_log = XFS_READIO_LOG_LARGE;
476 writeio_log = XFS_WRITEIO_LOG_LARGE;
477 }
478 } else {
479 readio_log = mp->m_readio_log;
480 writeio_log = mp->m_writeio_log;
481 }
482
483 if (sbp->sb_blocklog > readio_log) {
484 mp->m_readio_log = sbp->sb_blocklog;
485 } else {
486 mp->m_readio_log = readio_log;
487 }
488 mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
489 if (sbp->sb_blocklog > writeio_log) {
490 mp->m_writeio_log = sbp->sb_blocklog;
491 } else {
492 mp->m_writeio_log = writeio_log;
493 }
494 mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
495}
496
497/*
498 * precalculate the low space thresholds for dynamic speculative preallocation.
499 */
500void
501xfs_set_low_space_thresholds(
502 struct xfs_mount *mp)
503{
504 int i;
505
506 for (i = 0; i < XFS_LOWSP_MAX; i++) {
507 uint64_t space = mp->m_sb.sb_dblocks;
508
509 do_div(space, 100);
510 mp->m_low_space[i] = space * (i + 1);
511 }
512}
513
514
515/*
516 * Set whether we're using inode alignment.
517 */
518STATIC void
519xfs_set_inoalignment(xfs_mount_t *mp)
520{
521 if (xfs_sb_version_hasalign(&mp->m_sb) &&
522 mp->m_sb.sb_inoalignmt >= xfs_icluster_size_fsb(mp))
523 mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
524 else
525 mp->m_inoalign_mask = 0;
526 /*
527 * If we are using stripe alignment, check whether
528 * the stripe unit is a multiple of the inode alignment
529 */
530 if (mp->m_dalign && mp->m_inoalign_mask &&
531 !(mp->m_dalign & mp->m_inoalign_mask))
532 mp->m_sinoalign = mp->m_dalign;
533 else
534 mp->m_sinoalign = 0;
535}
536
537/*
538 * Check that the data (and log if separate) is an ok size.
539 */
540STATIC int
541xfs_check_sizes(
542 struct xfs_mount *mp)
543{
544 struct xfs_buf *bp;
545 xfs_daddr_t d;
546 int error;
547
548 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
549 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
550 xfs_warn(mp, "filesystem size mismatch detected");
551 return -EFBIG;
552 }
553 error = xfs_buf_read_uncached(mp->m_ddev_targp,
554 d - XFS_FSS_TO_BB(mp, 1),
555 XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
556 if (error) {
557 xfs_warn(mp, "last sector read failed");
558 return error;
559 }
560 xfs_buf_relse(bp);
561
562 if (mp->m_logdev_targp == mp->m_ddev_targp)
563 return 0;
564
565 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
566 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
567 xfs_warn(mp, "log size mismatch detected");
568 return -EFBIG;
569 }
570 error = xfs_buf_read_uncached(mp->m_logdev_targp,
571 d - XFS_FSB_TO_BB(mp, 1),
572 XFS_FSB_TO_BB(mp, 1), 0, &bp, NULL);
573 if (error) {
574 xfs_warn(mp, "log device read failed");
575 return error;
576 }
577 xfs_buf_relse(bp);
578 return 0;
579}
580
581/*
582 * Clear the quotaflags in memory and in the superblock.
583 */
584int
585xfs_mount_reset_sbqflags(
586 struct xfs_mount *mp)
587{
588 mp->m_qflags = 0;
589
590 /* It is OK to look at sb_qflags in the mount path without m_sb_lock. */
591 if (mp->m_sb.sb_qflags == 0)
592 return 0;
593 spin_lock(&mp->m_sb_lock);
594 mp->m_sb.sb_qflags = 0;
595 spin_unlock(&mp->m_sb_lock);
596
597 if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
598 return 0;
599
600 return xfs_sync_sb(mp, false);
601}
602
603uint64_t
604xfs_default_resblks(xfs_mount_t *mp)
605{
606 uint64_t resblks;
607
608 /*
609 * We default to 5% or 8192 fsbs of space reserved, whichever is
610 * smaller. This is intended to cover concurrent allocation
611 * transactions when we initially hit enospc. These each require a 4
612 * block reservation. Hence by default we cover roughly 2000 concurrent
613 * allocation reservations.
614 */
615 resblks = mp->m_sb.sb_dblocks;
616 do_div(resblks, 20);
617 resblks = min_t(uint64_t, resblks, 8192);
618 return resblks;
619}
620
621/*
622 * This function does the following on an initial mount of a file system:
623 * - reads the superblock from disk and init the mount struct
624 * - if we're a 32-bit kernel, do a size check on the superblock
625 * so we don't mount terabyte filesystems
626 * - init mount struct realtime fields
627 * - allocate inode hash table for fs
628 * - init directory manager
629 * - perform recovery and init the log manager
630 */
631int
632xfs_mountfs(
633 struct xfs_mount *mp)
634{
635 struct xfs_sb *sbp = &(mp->m_sb);
636 struct xfs_inode *rip;
637 uint64_t resblks;
638 uint quotamount = 0;
639 uint quotaflags = 0;
640 int error = 0;
641
642 xfs_sb_mount_common(mp, sbp);
643
644 /*
645 * Check for a mismatched features2 values. Older kernels read & wrote
646 * into the wrong sb offset for sb_features2 on some platforms due to
647 * xfs_sb_t not being 64bit size aligned when sb_features2 was added,
648 * which made older superblock reading/writing routines swap it as a
649 * 64-bit value.
650 *
651 * For backwards compatibility, we make both slots equal.
652 *
653 * If we detect a mismatched field, we OR the set bits into the existing
654 * features2 field in case it has already been modified; we don't want
655 * to lose any features. We then update the bad location with the ORed
656 * value so that older kernels will see any features2 flags. The
657 * superblock writeback code ensures the new sb_features2 is copied to
658 * sb_bad_features2 before it is logged or written to disk.
659 */
660 if (xfs_sb_has_mismatched_features2(sbp)) {
661 xfs_warn(mp, "correcting sb_features alignment problem");
662 sbp->sb_features2 |= sbp->sb_bad_features2;
663 mp->m_update_sb = true;
664
665 /*
666 * Re-check for ATTR2 in case it was found in bad_features2
667 * slot.
668 */
669 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
670 !(mp->m_flags & XFS_MOUNT_NOATTR2))
671 mp->m_flags |= XFS_MOUNT_ATTR2;
672 }
673
674 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
675 (mp->m_flags & XFS_MOUNT_NOATTR2)) {
676 xfs_sb_version_removeattr2(&mp->m_sb);
677 mp->m_update_sb = true;
678
679 /* update sb_versionnum for the clearing of the morebits */
680 if (!sbp->sb_features2)
681 mp->m_update_sb = true;
682 }
683
684 /* always use v2 inodes by default now */
685 if (!(mp->m_sb.sb_versionnum & XFS_SB_VERSION_NLINKBIT)) {
686 mp->m_sb.sb_versionnum |= XFS_SB_VERSION_NLINKBIT;
687 mp->m_update_sb = true;
688 }
689
690 /*
691 * Check if sb_agblocks is aligned at stripe boundary
692 * If sb_agblocks is NOT aligned turn off m_dalign since
693 * allocator alignment is within an ag, therefore ag has
694 * to be aligned at stripe boundary.
695 */
696 error = xfs_update_alignment(mp);
697 if (error)
698 goto out;
699
700 xfs_alloc_compute_maxlevels(mp);
701 xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
702 xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
703 xfs_ialloc_compute_maxlevels(mp);
704 xfs_rmapbt_compute_maxlevels(mp);
705 xfs_refcountbt_compute_maxlevels(mp);
706
707 xfs_set_maxicount(mp);
708
709 /* enable fail_at_unmount as default */
710 mp->m_fail_unmount = true;
711
712 error = xfs_sysfs_init(&mp->m_kobj, &xfs_mp_ktype, NULL, mp->m_fsname);
713 if (error)
714 goto out;
715
716 error = xfs_sysfs_init(&mp->m_stats.xs_kobj, &xfs_stats_ktype,
717 &mp->m_kobj, "stats");
718 if (error)
719 goto out_remove_sysfs;
720
721 error = xfs_error_sysfs_init(mp);
722 if (error)
723 goto out_del_stats;
724
725 error = xfs_errortag_init(mp);
726 if (error)
727 goto out_remove_error_sysfs;
728
729 error = xfs_uuid_mount(mp);
730 if (error)
731 goto out_remove_errortag;
732
733 /*
734 * Set the minimum read and write sizes
735 */
736 xfs_set_rw_sizes(mp);
737
738 /* set the low space thresholds for dynamic preallocation */
739 xfs_set_low_space_thresholds(mp);
740
741 /*
742 * Set the inode cluster size.
743 * This may still be overridden by the file system
744 * block size if it is larger than the chosen cluster size.
745 *
746 * For v5 filesystems, scale the cluster size with the inode size to
747 * keep a constant ratio of inode per cluster buffer, but only if mkfs
748 * has set the inode alignment value appropriately for larger cluster
749 * sizes.
750 */
751 mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
752 if (xfs_sb_version_hascrc(&mp->m_sb)) {
753 int new_size = mp->m_inode_cluster_size;
754
755 new_size *= mp->m_sb.sb_inodesize / XFS_DINODE_MIN_SIZE;
756 if (mp->m_sb.sb_inoalignmt >= XFS_B_TO_FSBT(mp, new_size))
757 mp->m_inode_cluster_size = new_size;
758 }
759
760 /*
761 * If enabled, sparse inode chunk alignment is expected to match the
762 * cluster size. Full inode chunk alignment must match the chunk size,
763 * but that is checked on sb read verification...
764 */
765 if (xfs_sb_version_hassparseinodes(&mp->m_sb) &&
766 mp->m_sb.sb_spino_align !=
767 XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size)) {
768 xfs_warn(mp,
769 "Sparse inode block alignment (%u) must match cluster size (%llu).",
770 mp->m_sb.sb_spino_align,
771 XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size));
772 error = -EINVAL;
773 goto out_remove_uuid;
774 }
775
776 /*
777 * Set inode alignment fields
778 */
779 xfs_set_inoalignment(mp);
780
781 /*
782 * Check that the data (and log if separate) is an ok size.
783 */
784 error = xfs_check_sizes(mp);
785 if (error)
786 goto out_remove_uuid;
787
788 /*
789 * Initialize realtime fields in the mount structure
790 */
791 error = xfs_rtmount_init(mp);
792 if (error) {
793 xfs_warn(mp, "RT mount failed");
794 goto out_remove_uuid;
795 }
796
797 /*
798 * Copies the low order bits of the timestamp and the randomly
799 * set "sequence" number out of a UUID.
800 */
801 mp->m_fixedfsid[0] =
802 (get_unaligned_be16(&sbp->sb_uuid.b[8]) << 16) |
803 get_unaligned_be16(&sbp->sb_uuid.b[4]);
804 mp->m_fixedfsid[1] = get_unaligned_be32(&sbp->sb_uuid.b[0]);
805
806 error = xfs_da_mount(mp);
807 if (error) {
808 xfs_warn(mp, "Failed dir/attr init: %d", error);
809 goto out_remove_uuid;
810 }
811
812 /*
813 * Initialize the precomputed transaction reservations values.
814 */
815 xfs_trans_init(mp);
816
817 /*
818 * Allocate and initialize the per-ag data.
819 */
820 error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
821 if (error) {
822 xfs_warn(mp, "Failed per-ag init: %d", error);
823 goto out_free_dir;
824 }
825
826 if (!sbp->sb_logblocks) {
827 xfs_warn(mp, "no log defined");
828 XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
829 error = -EFSCORRUPTED;
830 goto out_free_perag;
831 }
832
833 /*
834 * Log's mount-time initialization. The first part of recovery can place
835 * some items on the AIL, to be handled when recovery is finished or
836 * cancelled.
837 */
838 error = xfs_log_mount(mp, mp->m_logdev_targp,
839 XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
840 XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
841 if (error) {
842 xfs_warn(mp, "log mount failed");
843 goto out_fail_wait;
844 }
845
846 /*
847 * Now the log is mounted, we know if it was an unclean shutdown or
848 * not. If it was, with the first phase of recovery has completed, we
849 * have consistent AG blocks on disk. We have not recovered EFIs yet,
850 * but they are recovered transactionally in the second recovery phase
851 * later.
852 *
853 * Hence we can safely re-initialise incore superblock counters from
854 * the per-ag data. These may not be correct if the filesystem was not
855 * cleanly unmounted, so we need to wait for recovery to finish before
856 * doing this.
857 *
858 * If the filesystem was cleanly unmounted, then we can trust the
859 * values in the superblock to be correct and we don't need to do
860 * anything here.
861 *
862 * If we are currently making the filesystem, the initialisation will
863 * fail as the perag data is in an undefined state.
864 */
865 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
866 !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
867 !mp->m_sb.sb_inprogress) {
868 error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
869 if (error)
870 goto out_log_dealloc;
871 }
872
873 /*
874 * Get and sanity-check the root inode.
875 * Save the pointer to it in the mount structure.
876 */
877 error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip);
878 if (error) {
879 xfs_warn(mp, "failed to read root inode");
880 goto out_log_dealloc;
881 }
882
883 ASSERT(rip != NULL);
884
885 if (unlikely(!S_ISDIR(VFS_I(rip)->i_mode))) {
886 xfs_warn(mp, "corrupted root inode %llu: not a directory",
887 (unsigned long long)rip->i_ino);
888 xfs_iunlock(rip, XFS_ILOCK_EXCL);
889 XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
890 mp);
891 error = -EFSCORRUPTED;
892 goto out_rele_rip;
893 }
894 mp->m_rootip = rip; /* save it */
895
896 xfs_iunlock(rip, XFS_ILOCK_EXCL);
897
898 /*
899 * Initialize realtime inode pointers in the mount structure
900 */
901 error = xfs_rtmount_inodes(mp);
902 if (error) {
903 /*
904 * Free up the root inode.
905 */
906 xfs_warn(mp, "failed to read RT inodes");
907 goto out_rele_rip;
908 }
909
910 /*
911 * If this is a read-only mount defer the superblock updates until
912 * the next remount into writeable mode. Otherwise we would never
913 * perform the update e.g. for the root filesystem.
914 */
915 if (mp->m_update_sb && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
916 error = xfs_sync_sb(mp, false);
917 if (error) {
918 xfs_warn(mp, "failed to write sb changes");
919 goto out_rtunmount;
920 }
921 }
922
923 /*
924 * Initialise the XFS quota management subsystem for this mount
925 */
926 if (XFS_IS_QUOTA_RUNNING(mp)) {
927 error = xfs_qm_newmount(mp, "amount, "aflags);
928 if (error)
929 goto out_rtunmount;
930 } else {
931 ASSERT(!XFS_IS_QUOTA_ON(mp));
932
933 /*
934 * If a file system had quotas running earlier, but decided to
935 * mount without -o uquota/pquota/gquota options, revoke the
936 * quotachecked license.
937 */
938 if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
939 xfs_notice(mp, "resetting quota flags");
940 error = xfs_mount_reset_sbqflags(mp);
941 if (error)
942 goto out_rtunmount;
943 }
944 }
945
946 /*
947 * Finish recovering the file system. This part needed to be delayed
948 * until after the root and real-time bitmap inodes were consistently
949 * read in.
950 */
951 error = xfs_log_mount_finish(mp);
952 if (error) {
953 xfs_warn(mp, "log mount finish failed");
954 goto out_rtunmount;
955 }
956
957 /*
958 * Now the log is fully replayed, we can transition to full read-only
959 * mode for read-only mounts. This will sync all the metadata and clean
960 * the log so that the recovery we just performed does not have to be
961 * replayed again on the next mount.
962 *
963 * We use the same quiesce mechanism as the rw->ro remount, as they are
964 * semantically identical operations.
965 */
966 if ((mp->m_flags & (XFS_MOUNT_RDONLY|XFS_MOUNT_NORECOVERY)) ==
967 XFS_MOUNT_RDONLY) {
968 xfs_quiesce_attr(mp);
969 }
970
971 /*
972 * Complete the quota initialisation, post-log-replay component.
973 */
974 if (quotamount) {
975 ASSERT(mp->m_qflags == 0);
976 mp->m_qflags = quotaflags;
977
978 xfs_qm_mount_quotas(mp);
979 }
980
981 /*
982 * Now we are mounted, reserve a small amount of unused space for
983 * privileged transactions. This is needed so that transaction
984 * space required for critical operations can dip into this pool
985 * when at ENOSPC. This is needed for operations like create with
986 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
987 * are not allowed to use this reserved space.
988 *
989 * This may drive us straight to ENOSPC on mount, but that implies
990 * we were already there on the last unmount. Warn if this occurs.
991 */
992 if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
993 resblks = xfs_default_resblks(mp);
994 error = xfs_reserve_blocks(mp, &resblks, NULL);
995 if (error)
996 xfs_warn(mp,
997 "Unable to allocate reserve blocks. Continuing without reserve pool.");
998
999 /* Recover any CoW blocks that never got remapped. */
1000 error = xfs_reflink_recover_cow(mp);
1001 if (error) {
1002 xfs_err(mp,
1003 "Error %d recovering leftover CoW allocations.", error);
1004 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1005 goto out_quota;
1006 }
1007
1008 /* Reserve AG blocks for future btree expansion. */
1009 error = xfs_fs_reserve_ag_blocks(mp);
1010 if (error && error != -ENOSPC)
1011 goto out_agresv;
1012 }
1013
1014 return 0;
1015
1016 out_agresv:
1017 xfs_fs_unreserve_ag_blocks(mp);
1018 out_quota:
1019 xfs_qm_unmount_quotas(mp);
1020 out_rtunmount:
1021 xfs_rtunmount_inodes(mp);
1022 out_rele_rip:
1023 IRELE(rip);
1024 /* Clean out dquots that might be in memory after quotacheck. */
1025 xfs_qm_unmount(mp);
1026 /*
1027 * Cancel all delayed reclaim work and reclaim the inodes directly.
1028 * We have to do this /after/ rtunmount and qm_unmount because those
1029 * two will have scheduled delayed reclaim for the rt/quota inodes.
1030 *
1031 * This is slightly different from the unmountfs call sequence
1032 * because we could be tearing down a partially set up mount. In
1033 * particular, if log_mount_finish fails we bail out without calling
1034 * qm_unmount_quotas and therefore rely on qm_unmount to release the
1035 * quota inodes.
1036 */
1037 cancel_delayed_work_sync(&mp->m_reclaim_work);
1038 xfs_reclaim_inodes(mp, SYNC_WAIT);
1039 out_log_dealloc:
1040 mp->m_flags |= XFS_MOUNT_UNMOUNTING;
1041 xfs_log_mount_cancel(mp);
1042 out_fail_wait:
1043 if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
1044 xfs_wait_buftarg(mp->m_logdev_targp);
1045 xfs_wait_buftarg(mp->m_ddev_targp);
1046 out_free_perag:
1047 xfs_free_perag(mp);
1048 out_free_dir:
1049 xfs_da_unmount(mp);
1050 out_remove_uuid:
1051 xfs_uuid_unmount(mp);
1052 out_remove_errortag:
1053 xfs_errortag_del(mp);
1054 out_remove_error_sysfs:
1055 xfs_error_sysfs_del(mp);
1056 out_del_stats:
1057 xfs_sysfs_del(&mp->m_stats.xs_kobj);
1058 out_remove_sysfs:
1059 xfs_sysfs_del(&mp->m_kobj);
1060 out:
1061 return error;
1062}
1063
1064/*
1065 * This flushes out the inodes,dquots and the superblock, unmounts the
1066 * log and makes sure that incore structures are freed.
1067 */
1068void
1069xfs_unmountfs(
1070 struct xfs_mount *mp)
1071{
1072 uint64_t resblks;
1073 int error;
1074
1075 cancel_delayed_work_sync(&mp->m_eofblocks_work);
1076 cancel_delayed_work_sync(&mp->m_cowblocks_work);
1077
1078 xfs_fs_unreserve_ag_blocks(mp);
1079 xfs_qm_unmount_quotas(mp);
1080 xfs_rtunmount_inodes(mp);
1081 IRELE(mp->m_rootip);
1082
1083 /*
1084 * We can potentially deadlock here if we have an inode cluster
1085 * that has been freed has its buffer still pinned in memory because
1086 * the transaction is still sitting in a iclog. The stale inodes
1087 * on that buffer will have their flush locks held until the
1088 * transaction hits the disk and the callbacks run. the inode
1089 * flush takes the flush lock unconditionally and with nothing to
1090 * push out the iclog we will never get that unlocked. hence we
1091 * need to force the log first.
1092 */
1093 xfs_log_force(mp, XFS_LOG_SYNC);
1094
1095 /*
1096 * Wait for all busy extents to be freed, including completion of
1097 * any discard operation.
1098 */
1099 xfs_extent_busy_wait_all(mp);
1100 flush_workqueue(xfs_discard_wq);
1101
1102 /*
1103 * We now need to tell the world we are unmounting. This will allow
1104 * us to detect that the filesystem is going away and we should error
1105 * out anything that we have been retrying in the background. This will
1106 * prevent neverending retries in AIL pushing from hanging the unmount.
1107 */
1108 mp->m_flags |= XFS_MOUNT_UNMOUNTING;
1109
1110 /*
1111 * Flush all pending changes from the AIL.
1112 */
1113 xfs_ail_push_all_sync(mp->m_ail);
1114
1115 /*
1116 * And reclaim all inodes. At this point there should be no dirty
1117 * inodes and none should be pinned or locked, but use synchronous
1118 * reclaim just to be sure. We can stop background inode reclaim
1119 * here as well if it is still running.
1120 */
1121 cancel_delayed_work_sync(&mp->m_reclaim_work);
1122 xfs_reclaim_inodes(mp, SYNC_WAIT);
1123
1124 xfs_qm_unmount(mp);
1125
1126 /*
1127 * Unreserve any blocks we have so that when we unmount we don't account
1128 * the reserved free space as used. This is really only necessary for
1129 * lazy superblock counting because it trusts the incore superblock
1130 * counters to be absolutely correct on clean unmount.
1131 *
1132 * We don't bother correcting this elsewhere for lazy superblock
1133 * counting because on mount of an unclean filesystem we reconstruct the
1134 * correct counter value and this is irrelevant.
1135 *
1136 * For non-lazy counter filesystems, this doesn't matter at all because
1137 * we only every apply deltas to the superblock and hence the incore
1138 * value does not matter....
1139 */
1140 resblks = 0;
1141 error = xfs_reserve_blocks(mp, &resblks, NULL);
1142 if (error)
1143 xfs_warn(mp, "Unable to free reserved block pool. "
1144 "Freespace may not be correct on next mount.");
1145
1146 error = xfs_log_sbcount(mp);
1147 if (error)
1148 xfs_warn(mp, "Unable to update superblock counters. "
1149 "Freespace may not be correct on next mount.");
1150
1151
1152 xfs_log_unmount(mp);
1153 xfs_da_unmount(mp);
1154 xfs_uuid_unmount(mp);
1155
1156#if defined(DEBUG)
1157 xfs_errortag_clearall(mp);
1158#endif
1159 xfs_free_perag(mp);
1160
1161 xfs_errortag_del(mp);
1162 xfs_error_sysfs_del(mp);
1163 xfs_sysfs_del(&mp->m_stats.xs_kobj);
1164 xfs_sysfs_del(&mp->m_kobj);
1165}
1166
1167/*
1168 * Determine whether modifications can proceed. The caller specifies the minimum
1169 * freeze level for which modifications should not be allowed. This allows
1170 * certain operations to proceed while the freeze sequence is in progress, if
1171 * necessary.
1172 */
1173bool
1174xfs_fs_writable(
1175 struct xfs_mount *mp,
1176 int level)
1177{
1178 ASSERT(level > SB_UNFROZEN);
1179 if ((mp->m_super->s_writers.frozen >= level) ||
1180 XFS_FORCED_SHUTDOWN(mp) || (mp->m_flags & XFS_MOUNT_RDONLY))
1181 return false;
1182
1183 return true;
1184}
1185
1186/*
1187 * xfs_log_sbcount
1188 *
1189 * Sync the superblock counters to disk.
1190 *
1191 * Note this code can be called during the process of freezing, so we use the
1192 * transaction allocator that does not block when the transaction subsystem is
1193 * in its frozen state.
1194 */
1195int
1196xfs_log_sbcount(xfs_mount_t *mp)
1197{
1198 /* allow this to proceed during the freeze sequence... */
1199 if (!xfs_fs_writable(mp, SB_FREEZE_COMPLETE))
1200 return 0;
1201
1202 /*
1203 * we don't need to do this if we are updating the superblock
1204 * counters on every modification.
1205 */
1206 if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
1207 return 0;
1208
1209 return xfs_sync_sb(mp, true);
1210}
1211
1212/*
1213 * Deltas for the inode count are +/-64, hence we use a large batch size
1214 * of 128 so we don't need to take the counter lock on every update.
1215 */
1216#define XFS_ICOUNT_BATCH 128
1217int
1218xfs_mod_icount(
1219 struct xfs_mount *mp,
1220 int64_t delta)
1221{
1222 percpu_counter_add_batch(&mp->m_icount, delta, XFS_ICOUNT_BATCH);
1223 if (__percpu_counter_compare(&mp->m_icount, 0, XFS_ICOUNT_BATCH) < 0) {
1224 ASSERT(0);
1225 percpu_counter_add(&mp->m_icount, -delta);
1226 return -EINVAL;
1227 }
1228 return 0;
1229}
1230
1231int
1232xfs_mod_ifree(
1233 struct xfs_mount *mp,
1234 int64_t delta)
1235{
1236 percpu_counter_add(&mp->m_ifree, delta);
1237 if (percpu_counter_compare(&mp->m_ifree, 0) < 0) {
1238 ASSERT(0);
1239 percpu_counter_add(&mp->m_ifree, -delta);
1240 return -EINVAL;
1241 }
1242 return 0;
1243}
1244
1245/*
1246 * Deltas for the block count can vary from 1 to very large, but lock contention
1247 * only occurs on frequent small block count updates such as in the delayed
1248 * allocation path for buffered writes (page a time updates). Hence we set
1249 * a large batch count (1024) to minimise global counter updates except when
1250 * we get near to ENOSPC and we have to be very accurate with our updates.
1251 */
1252#define XFS_FDBLOCKS_BATCH 1024
1253int
1254xfs_mod_fdblocks(
1255 struct xfs_mount *mp,
1256 int64_t delta,
1257 bool rsvd)
1258{
1259 int64_t lcounter;
1260 long long res_used;
1261 s32 batch;
1262
1263 if (delta > 0) {
1264 /*
1265 * If the reserve pool is depleted, put blocks back into it
1266 * first. Most of the time the pool is full.
1267 */
1268 if (likely(mp->m_resblks == mp->m_resblks_avail)) {
1269 percpu_counter_add(&mp->m_fdblocks, delta);
1270 return 0;
1271 }
1272
1273 spin_lock(&mp->m_sb_lock);
1274 res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
1275
1276 if (res_used > delta) {
1277 mp->m_resblks_avail += delta;
1278 } else {
1279 delta -= res_used;
1280 mp->m_resblks_avail = mp->m_resblks;
1281 percpu_counter_add(&mp->m_fdblocks, delta);
1282 }
1283 spin_unlock(&mp->m_sb_lock);
1284 return 0;
1285 }
1286
1287 /*
1288 * Taking blocks away, need to be more accurate the closer we
1289 * are to zero.
1290 *
1291 * If the counter has a value of less than 2 * max batch size,
1292 * then make everything serialise as we are real close to
1293 * ENOSPC.
1294 */
1295 if (__percpu_counter_compare(&mp->m_fdblocks, 2 * XFS_FDBLOCKS_BATCH,
1296 XFS_FDBLOCKS_BATCH) < 0)
1297 batch = 1;
1298 else
1299 batch = XFS_FDBLOCKS_BATCH;
1300
1301 percpu_counter_add_batch(&mp->m_fdblocks, delta, batch);
1302 if (__percpu_counter_compare(&mp->m_fdblocks, mp->m_alloc_set_aside,
1303 XFS_FDBLOCKS_BATCH) >= 0) {
1304 /* we had space! */
1305 return 0;
1306 }
1307
1308 /*
1309 * lock up the sb for dipping into reserves before releasing the space
1310 * that took us to ENOSPC.
1311 */
1312 spin_lock(&mp->m_sb_lock);
1313 percpu_counter_add(&mp->m_fdblocks, -delta);
1314 if (!rsvd)
1315 goto fdblocks_enospc;
1316
1317 lcounter = (long long)mp->m_resblks_avail + delta;
1318 if (lcounter >= 0) {
1319 mp->m_resblks_avail = lcounter;
1320 spin_unlock(&mp->m_sb_lock);
1321 return 0;
1322 }
1323 printk_once(KERN_WARNING
1324 "Filesystem \"%s\": reserve blocks depleted! "
1325 "Consider increasing reserve pool size.",
1326 mp->m_fsname);
1327fdblocks_enospc:
1328 spin_unlock(&mp->m_sb_lock);
1329 return -ENOSPC;
1330}
1331
1332int
1333xfs_mod_frextents(
1334 struct xfs_mount *mp,
1335 int64_t delta)
1336{
1337 int64_t lcounter;
1338 int ret = 0;
1339
1340 spin_lock(&mp->m_sb_lock);
1341 lcounter = mp->m_sb.sb_frextents + delta;
1342 if (lcounter < 0)
1343 ret = -ENOSPC;
1344 else
1345 mp->m_sb.sb_frextents = lcounter;
1346 spin_unlock(&mp->m_sb_lock);
1347 return ret;
1348}
1349
1350/*
1351 * xfs_getsb() is called to obtain the buffer for the superblock.
1352 * The buffer is returned locked and read in from disk.
1353 * The buffer should be released with a call to xfs_brelse().
1354 *
1355 * If the flags parameter is BUF_TRYLOCK, then we'll only return
1356 * the superblock buffer if it can be locked without sleeping.
1357 * If it can't then we'll return NULL.
1358 */
1359struct xfs_buf *
1360xfs_getsb(
1361 struct xfs_mount *mp,
1362 int flags)
1363{
1364 struct xfs_buf *bp = mp->m_sb_bp;
1365
1366 if (!xfs_buf_trylock(bp)) {
1367 if (flags & XBF_TRYLOCK)
1368 return NULL;
1369 xfs_buf_lock(bp);
1370 }
1371
1372 xfs_buf_hold(bp);
1373 ASSERT(bp->b_flags & XBF_DONE);
1374 return bp;
1375}
1376
1377/*
1378 * Used to free the superblock along various error paths.
1379 */
1380void
1381xfs_freesb(
1382 struct xfs_mount *mp)
1383{
1384 struct xfs_buf *bp = mp->m_sb_bp;
1385
1386 xfs_buf_lock(bp);
1387 mp->m_sb_bp = NULL;
1388 xfs_buf_relse(bp);
1389}
1390
1391/*
1392 * If the underlying (data/log/rt) device is readonly, there are some
1393 * operations that cannot proceed.
1394 */
1395int
1396xfs_dev_is_read_only(
1397 struct xfs_mount *mp,
1398 char *message)
1399{
1400 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
1401 xfs_readonly_buftarg(mp->m_logdev_targp) ||
1402 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
1403 xfs_notice(mp, "%s required on read-only device.", message);
1404 xfs_notice(mp, "write access unavailable, cannot proceed.");
1405 return -EROFS;
1406 }
1407 return 0;
1408}
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_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"
45
46
47STATIC void xfs_unmountfs_wait(xfs_mount_t *);
48
49
50#ifdef HAVE_PERCPU_SB
51STATIC void xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t,
52 int);
53STATIC void xfs_icsb_balance_counter_locked(xfs_mount_t *, xfs_sb_field_t,
54 int);
55STATIC void xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
56#else
57
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
61
62static const struct {
63 short offset;
64 short type; /* 0 = integer
65 * 1 = binary / string (no translation)
66 */
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 }
115};
116
117static DEFINE_MUTEX(xfs_uuid_table_mutex);
118static int xfs_uuid_table_size;
119static uuid_t *xfs_uuid_table;
120
121/*
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.
124 */
125STATIC int
126xfs_uuid_mount(
127 struct xfs_mount *mp)
128{
129 uuid_t *uuid = &mp->m_sb.sb_uuid;
130 int hole, i;
131
132 if (mp->m_flags & XFS_MOUNT_NOUUID)
133 return 0;
134
135 if (uuid_is_nil(uuid)) {
136 xfs_warn(mp, "Filesystem has nil UUID - can't mount");
137 return XFS_ERROR(EINVAL);
138 }
139
140 mutex_lock(&xfs_uuid_table_mutex);
141 for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
142 if (uuid_is_nil(&xfs_uuid_table[i])) {
143 hole = i;
144 continue;
145 }
146 if (uuid_equal(uuid, &xfs_uuid_table[i]))
147 goto out_duplicate;
148 }
149
150 if (hole < 0) {
151 xfs_uuid_table = kmem_realloc(xfs_uuid_table,
152 (xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
153 xfs_uuid_table_size * sizeof(*xfs_uuid_table),
154 KM_SLEEP);
155 hole = xfs_uuid_table_size++;
156 }
157 xfs_uuid_table[hole] = *uuid;
158 mutex_unlock(&xfs_uuid_table_mutex);
159
160 return 0;
161
162 out_duplicate:
163 mutex_unlock(&xfs_uuid_table_mutex);
164 xfs_warn(mp, "Filesystem has duplicate UUID - can't mount");
165 return XFS_ERROR(EINVAL);
166}
167
168STATIC void
169xfs_uuid_unmount(
170 struct xfs_mount *mp)
171{
172 uuid_t *uuid = &mp->m_sb.sb_uuid;
173 int i;
174
175 if (mp->m_flags & XFS_MOUNT_NOUUID)
176 return;
177
178 mutex_lock(&xfs_uuid_table_mutex);
179 for (i = 0; i < xfs_uuid_table_size; i++) {
180 if (uuid_is_nil(&xfs_uuid_table[i]))
181 continue;
182 if (!uuid_equal(uuid, &xfs_uuid_table[i]))
183 continue;
184 memset(&xfs_uuid_table[i], 0, sizeof(uuid_t));
185 break;
186 }
187 ASSERT(i < xfs_uuid_table_size);
188 mutex_unlock(&xfs_uuid_table_mutex);
189}
190
191
192/*
193 * Reference counting access wrappers to the perag structures.
194 * Because we never free per-ag structures, the only thing we
195 * have to protect against changes is the tree structure itself.
196 */
197struct xfs_perag *
198xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
199{
200 struct xfs_perag *pag;
201 int ref = 0;
202
203 rcu_read_lock();
204 pag = radix_tree_lookup(&mp->m_perag_tree, agno);
205 if (pag) {
206 ASSERT(atomic_read(&pag->pag_ref) >= 0);
207 ref = atomic_inc_return(&pag->pag_ref);
208 }
209 rcu_read_unlock();
210 trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
211 return pag;
212}
213
214/*
215 * search from @first to find the next perag with the given tag set.
216 */
217struct xfs_perag *
218xfs_perag_get_tag(
219 struct xfs_mount *mp,
220 xfs_agnumber_t first,
221 int tag)
222{
223 struct xfs_perag *pag;
224 int found;
225 int ref;
226
227 rcu_read_lock();
228 found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
229 (void **)&pag, first, 1, tag);
230 if (found <= 0) {
231 rcu_read_unlock();
232 return NULL;
233 }
234 ref = atomic_inc_return(&pag->pag_ref);
235 rcu_read_unlock();
236 trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
237 return pag;
238}
239
240void
241xfs_perag_put(struct xfs_perag *pag)
242{
243 int ref;
244
245 ASSERT(atomic_read(&pag->pag_ref) > 0);
246 ref = atomic_dec_return(&pag->pag_ref);
247 trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
248}
249
250STATIC void
251__xfs_free_perag(
252 struct rcu_head *head)
253{
254 struct xfs_perag *pag = container_of(head, struct xfs_perag, rcu_head);
255
256 ASSERT(atomic_read(&pag->pag_ref) == 0);
257 kmem_free(pag);
258}
259
260/*
261 * Free up the per-ag resources associated with the mount structure.
262 */
263STATIC void
264xfs_free_perag(
265 xfs_mount_t *mp)
266{
267 xfs_agnumber_t agno;
268 struct xfs_perag *pag;
269
270 for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
271 spin_lock(&mp->m_perag_lock);
272 pag = radix_tree_delete(&mp->m_perag_tree, agno);
273 spin_unlock(&mp->m_perag_lock);
274 ASSERT(pag);
275 ASSERT(atomic_read(&pag->pag_ref) == 0);
276 call_rcu(&pag->rcu_head, __xfs_free_perag);
277 }
278}
279
280/*
281 * Check size of device based on the (data/realtime) block count.
282 * Note: this check is used by the growfs code as well as mount.
283 */
284int
285xfs_sb_validate_fsb_count(
286 xfs_sb_t *sbp,
287 __uint64_t nblocks)
288{
289 ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
290 ASSERT(sbp->sb_blocklog >= BBSHIFT);
291
292#if XFS_BIG_BLKNOS /* Limited by ULONG_MAX of page cache index */
293 if (nblocks >> (PAGE_CACHE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
294 return EFBIG;
295#else /* Limited by UINT_MAX of sectors */
296 if (nblocks << (sbp->sb_blocklog - BBSHIFT) > UINT_MAX)
297 return EFBIG;
298#endif
299 return 0;
300}
301
302/*
303 * Check the validity of the SB found.
304 */
305STATIC int
306xfs_mount_validate_sb(
307 xfs_mount_t *mp,
308 xfs_sb_t *sbp,
309 int flags)
310{
311 int loud = !(flags & XFS_MFSI_QUIET);
312
313 /*
314 * If the log device and data device have the
315 * same device number, the log is internal.
316 * Consequently, the sb_logstart should be non-zero. If
317 * we have a zero sb_logstart in this case, we may be trying to mount
318 * a volume filesystem in a non-volume manner.
319 */
320 if (sbp->sb_magicnum != XFS_SB_MAGIC) {
321 if (loud)
322 xfs_warn(mp, "bad magic number");
323 return XFS_ERROR(EWRONGFS);
324 }
325
326 if (!xfs_sb_good_version(sbp)) {
327 if (loud)
328 xfs_warn(mp, "bad version");
329 return XFS_ERROR(EWRONGFS);
330 }
331
332 if (unlikely(
333 sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
334 if (loud)
335 xfs_warn(mp,
336 "filesystem is marked as having an external log; "
337 "specify logdev on the mount command line.");
338 return XFS_ERROR(EINVAL);
339 }
340
341 if (unlikely(
342 sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
343 if (loud)
344 xfs_warn(mp,
345 "filesystem is marked as having an internal log; "
346 "do not specify logdev on the mount command line.");
347 return XFS_ERROR(EINVAL);
348 }
349
350 /*
351 * More sanity checking. Most of these were stolen directly from
352 * xfs_repair.
353 */
354 if (unlikely(
355 sbp->sb_agcount <= 0 ||
356 sbp->sb_sectsize < XFS_MIN_SECTORSIZE ||
357 sbp->sb_sectsize > XFS_MAX_SECTORSIZE ||
358 sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG ||
359 sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG ||
360 sbp->sb_sectsize != (1 << sbp->sb_sectlog) ||
361 sbp->sb_blocksize < XFS_MIN_BLOCKSIZE ||
362 sbp->sb_blocksize > XFS_MAX_BLOCKSIZE ||
363 sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG ||
364 sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
365 sbp->sb_blocksize != (1 << sbp->sb_blocklog) ||
366 sbp->sb_inodesize < XFS_DINODE_MIN_SIZE ||
367 sbp->sb_inodesize > XFS_DINODE_MAX_SIZE ||
368 sbp->sb_inodelog < XFS_DINODE_MIN_LOG ||
369 sbp->sb_inodelog > XFS_DINODE_MAX_LOG ||
370 sbp->sb_inodesize != (1 << sbp->sb_inodelog) ||
371 (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) ||
372 (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) ||
373 (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) ||
374 (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */) ||
375 sbp->sb_dblocks == 0 ||
376 sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp) ||
377 sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp))) {
378 if (loud)
379 XFS_CORRUPTION_ERROR("SB sanity check failed",
380 XFS_ERRLEVEL_LOW, mp, sbp);
381 return XFS_ERROR(EFSCORRUPTED);
382 }
383
384 /*
385 * Until this is fixed only page-sized or smaller data blocks work.
386 */
387 if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
388 if (loud) {
389 xfs_warn(mp,
390 "File system with blocksize %d bytes. "
391 "Only pagesize (%ld) or less will currently work.",
392 sbp->sb_blocksize, PAGE_SIZE);
393 }
394 return XFS_ERROR(ENOSYS);
395 }
396
397 /*
398 * Currently only very few inode sizes are supported.
399 */
400 switch (sbp->sb_inodesize) {
401 case 256:
402 case 512:
403 case 1024:
404 case 2048:
405 break;
406 default:
407 if (loud)
408 xfs_warn(mp, "inode size of %d bytes not supported",
409 sbp->sb_inodesize);
410 return XFS_ERROR(ENOSYS);
411 }
412
413 if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
414 xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
415 if (loud)
416 xfs_warn(mp,
417 "file system too large to be mounted on this system.");
418 return XFS_ERROR(EFBIG);
419 }
420
421 if (unlikely(sbp->sb_inprogress)) {
422 if (loud)
423 xfs_warn(mp, "file system busy");
424 return XFS_ERROR(EFSCORRUPTED);
425 }
426
427 /*
428 * Version 1 directory format has never worked on Linux.
429 */
430 if (unlikely(!xfs_sb_version_hasdirv2(sbp))) {
431 if (loud)
432 xfs_warn(mp,
433 "file system using version 1 directory format");
434 return XFS_ERROR(ENOSYS);
435 }
436
437 return 0;
438}
439
440int
441xfs_initialize_perag(
442 xfs_mount_t *mp,
443 xfs_agnumber_t agcount,
444 xfs_agnumber_t *maxagi)
445{
446 xfs_agnumber_t index, max_metadata;
447 xfs_agnumber_t first_initialised = 0;
448 xfs_perag_t *pag;
449 xfs_agino_t agino;
450 xfs_ino_t ino;
451 xfs_sb_t *sbp = &mp->m_sb;
452 int error = -ENOMEM;
453
454 /*
455 * Walk the current per-ag tree so we don't try to initialise AGs
456 * that already exist (growfs case). Allocate and insert all the
457 * AGs we don't find ready for initialisation.
458 */
459 for (index = 0; index < agcount; index++) {
460 pag = xfs_perag_get(mp, index);
461 if (pag) {
462 xfs_perag_put(pag);
463 continue;
464 }
465 if (!first_initialised)
466 first_initialised = index;
467
468 pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
469 if (!pag)
470 goto out_unwind;
471 pag->pag_agno = index;
472 pag->pag_mount = mp;
473 spin_lock_init(&pag->pag_ici_lock);
474 mutex_init(&pag->pag_ici_reclaim_lock);
475 INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
476 spin_lock_init(&pag->pag_buf_lock);
477 pag->pag_buf_tree = RB_ROOT;
478
479 if (radix_tree_preload(GFP_NOFS))
480 goto out_unwind;
481
482 spin_lock(&mp->m_perag_lock);
483 if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
484 BUG();
485 spin_unlock(&mp->m_perag_lock);
486 radix_tree_preload_end();
487 error = -EEXIST;
488 goto out_unwind;
489 }
490 spin_unlock(&mp->m_perag_lock);
491 radix_tree_preload_end();
492 }
493
494 /*
495 * If we mount with the inode64 option, or no inode overflows
496 * the legacy 32-bit address space clear the inode32 option.
497 */
498 agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
499 ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
500
501 if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
502 mp->m_flags |= XFS_MOUNT_32BITINODES;
503 else
504 mp->m_flags &= ~XFS_MOUNT_32BITINODES;
505
506 if (mp->m_flags & XFS_MOUNT_32BITINODES) {
507 /*
508 * Calculate how much should be reserved for inodes to meet
509 * the max inode percentage.
510 */
511 if (mp->m_maxicount) {
512 __uint64_t icount;
513
514 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
515 do_div(icount, 100);
516 icount += sbp->sb_agblocks - 1;
517 do_div(icount, sbp->sb_agblocks);
518 max_metadata = icount;
519 } else {
520 max_metadata = agcount;
521 }
522
523 for (index = 0; index < agcount; index++) {
524 ino = XFS_AGINO_TO_INO(mp, index, agino);
525 if (ino > XFS_MAXINUMBER_32) {
526 index++;
527 break;
528 }
529
530 pag = xfs_perag_get(mp, index);
531 pag->pagi_inodeok = 1;
532 if (index < max_metadata)
533 pag->pagf_metadata = 1;
534 xfs_perag_put(pag);
535 }
536 } else {
537 for (index = 0; index < agcount; index++) {
538 pag = xfs_perag_get(mp, index);
539 pag->pagi_inodeok = 1;
540 xfs_perag_put(pag);
541 }
542 }
543
544 if (maxagi)
545 *maxagi = index;
546 return 0;
547
548out_unwind:
549 kmem_free(pag);
550 for (; index > first_initialised; index--) {
551 pag = radix_tree_delete(&mp->m_perag_tree, index);
552 kmem_free(pag);
553 }
554 return error;
555}
556
557void
558xfs_sb_from_disk(
559 xfs_sb_t *to,
560 xfs_dsb_t *from)
561{
562 to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
563 to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
564 to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
565 to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
566 to->sb_rextents = be64_to_cpu(from->sb_rextents);
567 memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
568 to->sb_logstart = be64_to_cpu(from->sb_logstart);
569 to->sb_rootino = be64_to_cpu(from->sb_rootino);
570 to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
571 to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
572 to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
573 to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
574 to->sb_agcount = be32_to_cpu(from->sb_agcount);
575 to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
576 to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
577 to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
578 to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
579 to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
580 to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
581 memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
582 to->sb_blocklog = from->sb_blocklog;
583 to->sb_sectlog = from->sb_sectlog;
584 to->sb_inodelog = from->sb_inodelog;
585 to->sb_inopblog = from->sb_inopblog;
586 to->sb_agblklog = from->sb_agblklog;
587 to->sb_rextslog = from->sb_rextslog;
588 to->sb_inprogress = from->sb_inprogress;
589 to->sb_imax_pct = from->sb_imax_pct;
590 to->sb_icount = be64_to_cpu(from->sb_icount);
591 to->sb_ifree = be64_to_cpu(from->sb_ifree);
592 to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
593 to->sb_frextents = be64_to_cpu(from->sb_frextents);
594 to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
595 to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
596 to->sb_qflags = be16_to_cpu(from->sb_qflags);
597 to->sb_flags = from->sb_flags;
598 to->sb_shared_vn = from->sb_shared_vn;
599 to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
600 to->sb_unit = be32_to_cpu(from->sb_unit);
601 to->sb_width = be32_to_cpu(from->sb_width);
602 to->sb_dirblklog = from->sb_dirblklog;
603 to->sb_logsectlog = from->sb_logsectlog;
604 to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
605 to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
606 to->sb_features2 = be32_to_cpu(from->sb_features2);
607 to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
608}
609
610/*
611 * Copy in core superblock to ondisk one.
612 *
613 * The fields argument is mask of superblock fields to copy.
614 */
615void
616xfs_sb_to_disk(
617 xfs_dsb_t *to,
618 xfs_sb_t *from,
619 __int64_t fields)
620{
621 xfs_caddr_t to_ptr = (xfs_caddr_t)to;
622 xfs_caddr_t from_ptr = (xfs_caddr_t)from;
623 xfs_sb_field_t f;
624 int first;
625 int size;
626
627 ASSERT(fields);
628 if (!fields)
629 return;
630
631 while (fields) {
632 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
633 first = xfs_sb_info[f].offset;
634 size = xfs_sb_info[f + 1].offset - first;
635
636 ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
637
638 if (size == 1 || xfs_sb_info[f].type == 1) {
639 memcpy(to_ptr + first, from_ptr + first, size);
640 } else {
641 switch (size) {
642 case 2:
643 *(__be16 *)(to_ptr + first) =
644 cpu_to_be16(*(__u16 *)(from_ptr + first));
645 break;
646 case 4:
647 *(__be32 *)(to_ptr + first) =
648 cpu_to_be32(*(__u32 *)(from_ptr + first));
649 break;
650 case 8:
651 *(__be64 *)(to_ptr + first) =
652 cpu_to_be64(*(__u64 *)(from_ptr + first));
653 break;
654 default:
655 ASSERT(0);
656 }
657 }
658
659 fields &= ~(1LL << f);
660 }
661}
662
663/*
664 * xfs_readsb
665 *
666 * Does the initial read of the superblock.
667 */
668int
669xfs_readsb(xfs_mount_t *mp, int flags)
670{
671 unsigned int sector_size;
672 xfs_buf_t *bp;
673 int error;
674 int loud = !(flags & XFS_MFSI_QUIET);
675
676 ASSERT(mp->m_sb_bp == NULL);
677 ASSERT(mp->m_ddev_targp != NULL);
678
679 /*
680 * Allocate a (locked) buffer to hold the superblock.
681 * This will be kept around at all times to optimize
682 * access to the superblock.
683 */
684 sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
685
686reread:
687 bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
688 XFS_SB_DADDR, sector_size, 0);
689 if (!bp) {
690 if (loud)
691 xfs_warn(mp, "SB buffer read failed");
692 return EIO;
693 }
694
695 /*
696 * Initialize the mount structure from the superblock.
697 * But first do some basic consistency checking.
698 */
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 if (loud)
703 xfs_warn(mp, "SB validate failed");
704 goto release_buf;
705 }
706
707 /*
708 * We must be able to do sector-sized and sector-aligned IO.
709 */
710 if (sector_size > mp->m_sb.sb_sectsize) {
711 if (loud)
712 xfs_warn(mp, "device supports %u byte sectors (not %u)",
713 sector_size, mp->m_sb.sb_sectsize);
714 error = ENOSYS;
715 goto release_buf;
716 }
717
718 /*
719 * If device sector size is smaller than the superblock size,
720 * re-read the superblock so the buffer is correctly sized.
721 */
722 if (sector_size < mp->m_sb.sb_sectsize) {
723 xfs_buf_relse(bp);
724 sector_size = mp->m_sb.sb_sectsize;
725 goto reread;
726 }
727
728 /* Initialize per-cpu counters */
729 xfs_icsb_reinit_counters(mp);
730
731 mp->m_sb_bp = bp;
732 xfs_buf_unlock(bp);
733 return 0;
734
735release_buf:
736 xfs_buf_relse(bp);
737 return error;
738}
739
740
741/*
742 * xfs_mount_common
743 *
744 * Mount initialization code establishing various mount
745 * fields from the superblock associated with the given
746 * mount structure
747 */
748STATIC void
749xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
750{
751 mp->m_agfrotor = mp->m_agirotor = 0;
752 spin_lock_init(&mp->m_agirotor_lock);
753 mp->m_maxagi = mp->m_sb.sb_agcount;
754 mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
755 mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
756 mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
757 mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
758 mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
759 mp->m_blockmask = sbp->sb_blocksize - 1;
760 mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
761 mp->m_blockwmask = mp->m_blockwsize - 1;
762
763 mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
764 mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
765 mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
766 mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
767
768 mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
769 mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
770 mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
771 mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
772
773 mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
774 mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
775 mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
776 mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
777
778 mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
779 mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
780 sbp->sb_inopblock);
781 mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
782}
783
784/*
785 * xfs_initialize_perag_data
786 *
787 * Read in each per-ag structure so we can count up the number of
788 * allocated inodes, free inodes and used filesystem blocks as this
789 * information is no longer persistent in the superblock. Once we have
790 * this information, write it into the in-core superblock structure.
791 */
792STATIC int
793xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount)
794{
795 xfs_agnumber_t index;
796 xfs_perag_t *pag;
797 xfs_sb_t *sbp = &mp->m_sb;
798 uint64_t ifree = 0;
799 uint64_t ialloc = 0;
800 uint64_t bfree = 0;
801 uint64_t bfreelst = 0;
802 uint64_t btree = 0;
803 int error;
804
805 for (index = 0; index < agcount; index++) {
806 /*
807 * read the agf, then the agi. This gets us
808 * all the information we need and populates the
809 * per-ag structures for us.
810 */
811 error = xfs_alloc_pagf_init(mp, NULL, index, 0);
812 if (error)
813 return error;
814
815 error = xfs_ialloc_pagi_init(mp, NULL, index);
816 if (error)
817 return error;
818 pag = xfs_perag_get(mp, index);
819 ifree += pag->pagi_freecount;
820 ialloc += pag->pagi_count;
821 bfree += pag->pagf_freeblks;
822 bfreelst += pag->pagf_flcount;
823 btree += pag->pagf_btreeblks;
824 xfs_perag_put(pag);
825 }
826 /*
827 * Overwrite incore superblock counters with just-read data
828 */
829 spin_lock(&mp->m_sb_lock);
830 sbp->sb_ifree = ifree;
831 sbp->sb_icount = ialloc;
832 sbp->sb_fdblocks = bfree + bfreelst + btree;
833 spin_unlock(&mp->m_sb_lock);
834
835 /* Fixup the per-cpu counters as well. */
836 xfs_icsb_reinit_counters(mp);
837
838 return 0;
839}
840
841/*
842 * Update alignment values based on mount options and sb values
843 */
844STATIC int
845xfs_update_alignment(xfs_mount_t *mp)
846{
847 xfs_sb_t *sbp = &(mp->m_sb);
848
849 if (mp->m_dalign) {
850 /*
851 * If stripe unit and stripe width are not multiples
852 * of the fs blocksize turn off alignment.
853 */
854 if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
855 (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
856 if (mp->m_flags & XFS_MOUNT_RETERR) {
857 xfs_warn(mp, "alignment check failed: "
858 "(sunit/swidth vs. blocksize)");
859 return XFS_ERROR(EINVAL);
860 }
861 mp->m_dalign = mp->m_swidth = 0;
862 } else {
863 /*
864 * Convert the stripe unit and width to FSBs.
865 */
866 mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
867 if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
868 if (mp->m_flags & XFS_MOUNT_RETERR) {
869 xfs_warn(mp, "alignment check failed: "
870 "(sunit/swidth vs. ag size)");
871 return XFS_ERROR(EINVAL);
872 }
873 xfs_warn(mp,
874 "stripe alignment turned off: sunit(%d)/swidth(%d) "
875 "incompatible with agsize(%d)",
876 mp->m_dalign, mp->m_swidth,
877 sbp->sb_agblocks);
878
879 mp->m_dalign = 0;
880 mp->m_swidth = 0;
881 } else if (mp->m_dalign) {
882 mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
883 } else {
884 if (mp->m_flags & XFS_MOUNT_RETERR) {
885 xfs_warn(mp, "alignment check failed: "
886 "sunit(%d) less than bsize(%d)",
887 mp->m_dalign,
888 mp->m_blockmask +1);
889 return XFS_ERROR(EINVAL);
890 }
891 mp->m_swidth = 0;
892 }
893 }
894
895 /*
896 * Update superblock with new values
897 * and log changes
898 */
899 if (xfs_sb_version_hasdalign(sbp)) {
900 if (sbp->sb_unit != mp->m_dalign) {
901 sbp->sb_unit = mp->m_dalign;
902 mp->m_update_flags |= XFS_SB_UNIT;
903 }
904 if (sbp->sb_width != mp->m_swidth) {
905 sbp->sb_width = mp->m_swidth;
906 mp->m_update_flags |= XFS_SB_WIDTH;
907 }
908 }
909 } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
910 xfs_sb_version_hasdalign(&mp->m_sb)) {
911 mp->m_dalign = sbp->sb_unit;
912 mp->m_swidth = sbp->sb_width;
913 }
914
915 return 0;
916}
917
918/*
919 * Set the maximum inode count for this filesystem
920 */
921STATIC void
922xfs_set_maxicount(xfs_mount_t *mp)
923{
924 xfs_sb_t *sbp = &(mp->m_sb);
925 __uint64_t icount;
926
927 if (sbp->sb_imax_pct) {
928 /*
929 * Make sure the maximum inode count is a multiple
930 * of the units we allocate inodes in.
931 */
932 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
933 do_div(icount, 100);
934 do_div(icount, mp->m_ialloc_blks);
935 mp->m_maxicount = (icount * mp->m_ialloc_blks) <<
936 sbp->sb_inopblog;
937 } else {
938 mp->m_maxicount = 0;
939 }
940}
941
942/*
943 * Set the default minimum read and write sizes unless
944 * already specified in a mount option.
945 * We use smaller I/O sizes when the file system
946 * is being used for NFS service (wsync mount option).
947 */
948STATIC void
949xfs_set_rw_sizes(xfs_mount_t *mp)
950{
951 xfs_sb_t *sbp = &(mp->m_sb);
952 int readio_log, writeio_log;
953
954 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
955 if (mp->m_flags & XFS_MOUNT_WSYNC) {
956 readio_log = XFS_WSYNC_READIO_LOG;
957 writeio_log = XFS_WSYNC_WRITEIO_LOG;
958 } else {
959 readio_log = XFS_READIO_LOG_LARGE;
960 writeio_log = XFS_WRITEIO_LOG_LARGE;
961 }
962 } else {
963 readio_log = mp->m_readio_log;
964 writeio_log = mp->m_writeio_log;
965 }
966
967 if (sbp->sb_blocklog > readio_log) {
968 mp->m_readio_log = sbp->sb_blocklog;
969 } else {
970 mp->m_readio_log = readio_log;
971 }
972 mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
973 if (sbp->sb_blocklog > writeio_log) {
974 mp->m_writeio_log = sbp->sb_blocklog;
975 } else {
976 mp->m_writeio_log = writeio_log;
977 }
978 mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
979}
980
981/*
982 * precalculate the low space thresholds for dynamic speculative preallocation.
983 */
984void
985xfs_set_low_space_thresholds(
986 struct xfs_mount *mp)
987{
988 int i;
989
990 for (i = 0; i < XFS_LOWSP_MAX; i++) {
991 __uint64_t space = mp->m_sb.sb_dblocks;
992
993 do_div(space, 100);
994 mp->m_low_space[i] = space * (i + 1);
995 }
996}
997
998
999/*
1000 * Set whether we're using inode alignment.
1001 */
1002STATIC void
1003xfs_set_inoalignment(xfs_mount_t *mp)
1004{
1005 if (xfs_sb_version_hasalign(&mp->m_sb) &&
1006 mp->m_sb.sb_inoalignmt >=
1007 XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size))
1008 mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
1009 else
1010 mp->m_inoalign_mask = 0;
1011 /*
1012 * If we are using stripe alignment, check whether
1013 * the stripe unit is a multiple of the inode alignment
1014 */
1015 if (mp->m_dalign && mp->m_inoalign_mask &&
1016 !(mp->m_dalign & mp->m_inoalign_mask))
1017 mp->m_sinoalign = mp->m_dalign;
1018 else
1019 mp->m_sinoalign = 0;
1020}
1021
1022/*
1023 * Check that the data (and log if separate) are an ok size.
1024 */
1025STATIC int
1026xfs_check_sizes(xfs_mount_t *mp)
1027{
1028 xfs_buf_t *bp;
1029 xfs_daddr_t d;
1030
1031 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
1032 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
1033 xfs_warn(mp, "filesystem size mismatch detected");
1034 return XFS_ERROR(EFBIG);
1035 }
1036 bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
1037 d - XFS_FSS_TO_BB(mp, 1),
1038 BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
1039 if (!bp) {
1040 xfs_warn(mp, "last sector read failed");
1041 return EIO;
1042 }
1043 xfs_buf_relse(bp);
1044
1045 if (mp->m_logdev_targp != mp->m_ddev_targp) {
1046 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
1047 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
1048 xfs_warn(mp, "log size mismatch detected");
1049 return XFS_ERROR(EFBIG);
1050 }
1051 bp = xfs_buf_read_uncached(mp, mp->m_logdev_targp,
1052 d - XFS_FSB_TO_BB(mp, 1),
1053 XFS_FSB_TO_B(mp, 1), 0);
1054 if (!bp) {
1055 xfs_warn(mp, "log device read failed");
1056 return EIO;
1057 }
1058 xfs_buf_relse(bp);
1059 }
1060 return 0;
1061}
1062
1063/*
1064 * Clear the quotaflags in memory and in the superblock.
1065 */
1066int
1067xfs_mount_reset_sbqflags(
1068 struct xfs_mount *mp)
1069{
1070 int error;
1071 struct xfs_trans *tp;
1072
1073 mp->m_qflags = 0;
1074
1075 /*
1076 * It is OK to look at sb_qflags here in mount path,
1077 * without m_sb_lock.
1078 */
1079 if (mp->m_sb.sb_qflags == 0)
1080 return 0;
1081 spin_lock(&mp->m_sb_lock);
1082 mp->m_sb.sb_qflags = 0;
1083 spin_unlock(&mp->m_sb_lock);
1084
1085 /*
1086 * If the fs is readonly, let the incore superblock run
1087 * with quotas off but don't flush the update out to disk
1088 */
1089 if (mp->m_flags & XFS_MOUNT_RDONLY)
1090 return 0;
1091
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_alert(mp, "%s: Superblock update failed!", __func__);
1098 return error;
1099 }
1100
1101 xfs_mod_sb(tp, XFS_SB_QFLAGS);
1102 return xfs_trans_commit(tp, 0);
1103}
1104
1105__uint64_t
1106xfs_default_resblks(xfs_mount_t *mp)
1107{
1108 __uint64_t resblks;
1109
1110 /*
1111 * We default to 5% or 8192 fsbs of space reserved, whichever is
1112 * smaller. This is intended to cover concurrent allocation
1113 * transactions when we initially hit enospc. These each require a 4
1114 * block reservation. Hence by default we cover roughly 2000 concurrent
1115 * allocation reservations.
1116 */
1117 resblks = mp->m_sb.sb_dblocks;
1118 do_div(resblks, 20);
1119 resblks = min_t(__uint64_t, resblks, 8192);
1120 return resblks;
1121}
1122
1123/*
1124 * This function does the following on an initial mount of a file system:
1125 * - reads the superblock from disk and init the mount struct
1126 * - if we're a 32-bit kernel, do a size check on the superblock
1127 * so we don't mount terabyte filesystems
1128 * - init mount struct realtime fields
1129 * - allocate inode hash table for fs
1130 * - init directory manager
1131 * - perform recovery and init the log manager
1132 */
1133int
1134xfs_mountfs(
1135 xfs_mount_t *mp)
1136{
1137 xfs_sb_t *sbp = &(mp->m_sb);
1138 xfs_inode_t *rip;
1139 __uint64_t resblks;
1140 uint quotamount = 0;
1141 uint quotaflags = 0;
1142 int error = 0;
1143
1144 xfs_mount_common(mp, sbp);
1145
1146 /*
1147 * Check for a mismatched features2 values. Older kernels
1148 * read & wrote into the wrong sb offset for sb_features2
1149 * on some platforms due to xfs_sb_t not being 64bit size aligned
1150 * when sb_features2 was added, which made older superblock
1151 * reading/writing routines swap it as a 64-bit value.
1152 *
1153 * For backwards compatibility, we make both slots equal.
1154 *
1155 * If we detect a mismatched field, we OR the set bits into the
1156 * existing features2 field in case it has already been modified; we
1157 * don't want to lose any features. We then update the bad location
1158 * with the ORed value so that older kernels will see any features2
1159 * flags, and mark the two fields as needing updates once the
1160 * transaction subsystem is online.
1161 */
1162 if (xfs_sb_has_mismatched_features2(sbp)) {
1163 xfs_warn(mp, "correcting sb_features alignment problem");
1164 sbp->sb_features2 |= sbp->sb_bad_features2;
1165 sbp->sb_bad_features2 = sbp->sb_features2;
1166 mp->m_update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
1167
1168 /*
1169 * Re-check for ATTR2 in case it was found in bad_features2
1170 * slot.
1171 */
1172 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
1173 !(mp->m_flags & XFS_MOUNT_NOATTR2))
1174 mp->m_flags |= XFS_MOUNT_ATTR2;
1175 }
1176
1177 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
1178 (mp->m_flags & XFS_MOUNT_NOATTR2)) {
1179 xfs_sb_version_removeattr2(&mp->m_sb);
1180 mp->m_update_flags |= XFS_SB_FEATURES2;
1181
1182 /* update sb_versionnum for the clearing of the morebits */
1183 if (!sbp->sb_features2)
1184 mp->m_update_flags |= XFS_SB_VERSIONNUM;
1185 }
1186
1187 /*
1188 * Check if sb_agblocks is aligned at stripe boundary
1189 * If sb_agblocks is NOT aligned turn off m_dalign since
1190 * allocator alignment is within an ag, therefore ag has
1191 * to be aligned at stripe boundary.
1192 */
1193 error = xfs_update_alignment(mp);
1194 if (error)
1195 goto out;
1196
1197 xfs_alloc_compute_maxlevels(mp);
1198 xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
1199 xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
1200 xfs_ialloc_compute_maxlevels(mp);
1201
1202 xfs_set_maxicount(mp);
1203
1204 mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog);
1205
1206 error = xfs_uuid_mount(mp);
1207 if (error)
1208 goto out;
1209
1210 /*
1211 * Set the minimum read and write sizes
1212 */
1213 xfs_set_rw_sizes(mp);
1214
1215 /* set the low space thresholds for dynamic preallocation */
1216 xfs_set_low_space_thresholds(mp);
1217
1218 /*
1219 * Set the inode cluster size.
1220 * This may still be overridden by the file system
1221 * block size if it is larger than the chosen cluster size.
1222 */
1223 mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
1224
1225 /*
1226 * Set inode alignment fields
1227 */
1228 xfs_set_inoalignment(mp);
1229
1230 /*
1231 * Check that the data (and log if separate) are an ok size.
1232 */
1233 error = xfs_check_sizes(mp);
1234 if (error)
1235 goto out_remove_uuid;
1236
1237 /*
1238 * Initialize realtime fields in the mount structure
1239 */
1240 error = xfs_rtmount_init(mp);
1241 if (error) {
1242 xfs_warn(mp, "RT mount failed");
1243 goto out_remove_uuid;
1244 }
1245
1246 /*
1247 * Copies the low order bits of the timestamp and the randomly
1248 * set "sequence" number out of a UUID.
1249 */
1250 uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
1251
1252 mp->m_dmevmask = 0; /* not persistent; set after each mount */
1253
1254 xfs_dir_mount(mp);
1255
1256 /*
1257 * Initialize the attribute manager's entries.
1258 */
1259 mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100;
1260
1261 /*
1262 * Initialize the precomputed transaction reservations values.
1263 */
1264 xfs_trans_init(mp);
1265
1266 /*
1267 * Allocate and initialize the per-ag data.
1268 */
1269 spin_lock_init(&mp->m_perag_lock);
1270 INIT_RADIX_TREE(&mp->m_perag_tree, GFP_ATOMIC);
1271 error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
1272 if (error) {
1273 xfs_warn(mp, "Failed per-ag init: %d", error);
1274 goto out_remove_uuid;
1275 }
1276
1277 if (!sbp->sb_logblocks) {
1278 xfs_warn(mp, "no log defined");
1279 XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
1280 error = XFS_ERROR(EFSCORRUPTED);
1281 goto out_free_perag;
1282 }
1283
1284 /*
1285 * log's mount-time initialization. Perform 1st part recovery if needed
1286 */
1287 error = xfs_log_mount(mp, mp->m_logdev_targp,
1288 XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
1289 XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
1290 if (error) {
1291 xfs_warn(mp, "log mount failed");
1292 goto out_free_perag;
1293 }
1294
1295 /*
1296 * Now the log is mounted, we know if it was an unclean shutdown or
1297 * not. If it was, with the first phase of recovery has completed, we
1298 * have consistent AG blocks on disk. We have not recovered EFIs yet,
1299 * but they are recovered transactionally in the second recovery phase
1300 * later.
1301 *
1302 * Hence we can safely re-initialise incore superblock counters from
1303 * the per-ag data. These may not be correct if the filesystem was not
1304 * cleanly unmounted, so we need to wait for recovery to finish before
1305 * doing this.
1306 *
1307 * If the filesystem was cleanly unmounted, then we can trust the
1308 * values in the superblock to be correct and we don't need to do
1309 * anything here.
1310 *
1311 * If we are currently making the filesystem, the initialisation will
1312 * fail as the perag data is in an undefined state.
1313 */
1314 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
1315 !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
1316 !mp->m_sb.sb_inprogress) {
1317 error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
1318 if (error)
1319 goto out_free_perag;
1320 }
1321
1322 /*
1323 * Get and sanity-check the root inode.
1324 * Save the pointer to it in the mount structure.
1325 */
1326 error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip);
1327 if (error) {
1328 xfs_warn(mp, "failed to read root inode");
1329 goto out_log_dealloc;
1330 }
1331
1332 ASSERT(rip != NULL);
1333
1334 if (unlikely(!S_ISDIR(rip->i_d.di_mode))) {
1335 xfs_warn(mp, "corrupted root inode %llu: not a directory",
1336 (unsigned long long)rip->i_ino);
1337 xfs_iunlock(rip, XFS_ILOCK_EXCL);
1338 XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
1339 mp);
1340 error = XFS_ERROR(EFSCORRUPTED);
1341 goto out_rele_rip;
1342 }
1343 mp->m_rootip = rip; /* save it */
1344
1345 xfs_iunlock(rip, XFS_ILOCK_EXCL);
1346
1347 /*
1348 * Initialize realtime inode pointers in the mount structure
1349 */
1350 error = xfs_rtmount_inodes(mp);
1351 if (error) {
1352 /*
1353 * Free up the root inode.
1354 */
1355 xfs_warn(mp, "failed to read RT inodes");
1356 goto out_rele_rip;
1357 }
1358
1359 /*
1360 * If this is a read-only mount defer the superblock updates until
1361 * the next remount into writeable mode. Otherwise we would never
1362 * perform the update e.g. for the root filesystem.
1363 */
1364 if (mp->m_update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
1365 error = xfs_mount_log_sb(mp, mp->m_update_flags);
1366 if (error) {
1367 xfs_warn(mp, "failed to write sb changes");
1368 goto out_rtunmount;
1369 }
1370 }
1371
1372 /*
1373 * Initialise the XFS quota management subsystem for this mount
1374 */
1375 if (XFS_IS_QUOTA_RUNNING(mp)) {
1376 error = xfs_qm_newmount(mp, "amount, "aflags);
1377 if (error)
1378 goto out_rtunmount;
1379 } else {
1380 ASSERT(!XFS_IS_QUOTA_ON(mp));
1381
1382 /*
1383 * If a file system had quotas running earlier, but decided to
1384 * mount without -o uquota/pquota/gquota options, revoke the
1385 * quotachecked license.
1386 */
1387 if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
1388 xfs_notice(mp, "resetting quota flags");
1389 error = xfs_mount_reset_sbqflags(mp);
1390 if (error)
1391 return error;
1392 }
1393 }
1394
1395 /*
1396 * Finish recovering the file system. This part needed to be
1397 * delayed until after the root and real-time bitmap inodes
1398 * were consistently read in.
1399 */
1400 error = xfs_log_mount_finish(mp);
1401 if (error) {
1402 xfs_warn(mp, "log mount finish failed");
1403 goto out_rtunmount;
1404 }
1405
1406 /*
1407 * Complete the quota initialisation, post-log-replay component.
1408 */
1409 if (quotamount) {
1410 ASSERT(mp->m_qflags == 0);
1411 mp->m_qflags = quotaflags;
1412
1413 xfs_qm_mount_quotas(mp);
1414 }
1415
1416 /*
1417 * Now we are mounted, reserve a small amount of unused space for
1418 * privileged transactions. This is needed so that transaction
1419 * space required for critical operations can dip into this pool
1420 * when at ENOSPC. This is needed for operations like create with
1421 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
1422 * are not allowed to use this reserved space.
1423 *
1424 * This may drive us straight to ENOSPC on mount, but that implies
1425 * we were already there on the last unmount. Warn if this occurs.
1426 */
1427 if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
1428 resblks = xfs_default_resblks(mp);
1429 error = xfs_reserve_blocks(mp, &resblks, NULL);
1430 if (error)
1431 xfs_warn(mp,
1432 "Unable to allocate reserve blocks. Continuing without reserve pool.");
1433 }
1434
1435 return 0;
1436
1437 out_rtunmount:
1438 xfs_rtunmount_inodes(mp);
1439 out_rele_rip:
1440 IRELE(rip);
1441 out_log_dealloc:
1442 xfs_log_unmount(mp);
1443 out_free_perag:
1444 xfs_free_perag(mp);
1445 out_remove_uuid:
1446 xfs_uuid_unmount(mp);
1447 out:
1448 return error;
1449}
1450
1451/*
1452 * This flushes out the inodes,dquots and the superblock, unmounts the
1453 * log and makes sure that incore structures are freed.
1454 */
1455void
1456xfs_unmountfs(
1457 struct xfs_mount *mp)
1458{
1459 __uint64_t resblks;
1460 int error;
1461
1462 xfs_qm_unmount_quotas(mp);
1463 xfs_rtunmount_inodes(mp);
1464 IRELE(mp->m_rootip);
1465
1466 /*
1467 * We can potentially deadlock here if we have an inode cluster
1468 * that has been freed has its buffer still pinned in memory because
1469 * the transaction is still sitting in a iclog. The stale inodes
1470 * on that buffer will have their flush locks held until the
1471 * transaction hits the disk and the callbacks run. the inode
1472 * flush takes the flush lock unconditionally and with nothing to
1473 * push out the iclog we will never get that unlocked. hence we
1474 * need to force the log first.
1475 */
1476 xfs_log_force(mp, XFS_LOG_SYNC);
1477
1478 /*
1479 * Do a delwri reclaim pass first so that as many dirty inodes are
1480 * queued up for IO as possible. Then flush the buffers before making
1481 * a synchronous path to catch all the remaining inodes are reclaimed.
1482 * This makes the reclaim process as quick as possible by avoiding
1483 * synchronous writeout and blocking on inodes already in the delwri
1484 * state as much as possible.
1485 */
1486 xfs_reclaim_inodes(mp, 0);
1487 XFS_bflush(mp->m_ddev_targp);
1488 xfs_reclaim_inodes(mp, SYNC_WAIT);
1489
1490 xfs_qm_unmount(mp);
1491
1492 /*
1493 * Flush out the log synchronously so that we know for sure
1494 * that nothing is pinned. This is important because bflush()
1495 * will skip pinned buffers.
1496 */
1497 xfs_log_force(mp, XFS_LOG_SYNC);
1498
1499 xfs_binval(mp->m_ddev_targp);
1500 if (mp->m_rtdev_targp) {
1501 xfs_binval(mp->m_rtdev_targp);
1502 }
1503
1504 /*
1505 * Unreserve any blocks we have so that when we unmount we don't account
1506 * the reserved free space as used. This is really only necessary for
1507 * lazy superblock counting because it trusts the incore superblock
1508 * counters to be absolutely correct on clean unmount.
1509 *
1510 * We don't bother correcting this elsewhere for lazy superblock
1511 * counting because on mount of an unclean filesystem we reconstruct the
1512 * correct counter value and this is irrelevant.
1513 *
1514 * For non-lazy counter filesystems, this doesn't matter at all because
1515 * we only every apply deltas to the superblock and hence the incore
1516 * value does not matter....
1517 */
1518 resblks = 0;
1519 error = xfs_reserve_blocks(mp, &resblks, NULL);
1520 if (error)
1521 xfs_warn(mp, "Unable to free reserved block pool. "
1522 "Freespace may not be correct on next mount.");
1523
1524 error = xfs_log_sbcount(mp);
1525 if (error)
1526 xfs_warn(mp, "Unable to update superblock counters. "
1527 "Freespace may not be correct on next mount.");
1528 xfs_unmountfs_writesb(mp);
1529 xfs_unmountfs_wait(mp); /* wait for async bufs */
1530 xfs_log_unmount_write(mp);
1531 xfs_log_unmount(mp);
1532 xfs_uuid_unmount(mp);
1533
1534#if defined(DEBUG)
1535 xfs_errortag_clearall(mp, 0);
1536#endif
1537 xfs_free_perag(mp);
1538}
1539
1540STATIC void
1541xfs_unmountfs_wait(xfs_mount_t *mp)
1542{
1543 if (mp->m_logdev_targp != mp->m_ddev_targp)
1544 xfs_wait_buftarg(mp->m_logdev_targp);
1545 if (mp->m_rtdev_targp)
1546 xfs_wait_buftarg(mp->m_rtdev_targp);
1547 xfs_wait_buftarg(mp->m_ddev_targp);
1548}
1549
1550int
1551xfs_fs_writable(xfs_mount_t *mp)
1552{
1553 return !(xfs_test_for_freeze(mp) || XFS_FORCED_SHUTDOWN(mp) ||
1554 (mp->m_flags & XFS_MOUNT_RDONLY));
1555}
1556
1557/*
1558 * xfs_log_sbcount
1559 *
1560 * Sync the superblock counters to disk.
1561 *
1562 * Note this code can be called during the process of freezing, so
1563 * we may need to use the transaction allocator which does not
1564 * block when the transaction subsystem is in its frozen state.
1565 */
1566int
1567xfs_log_sbcount(xfs_mount_t *mp)
1568{
1569 xfs_trans_t *tp;
1570 int error;
1571
1572 if (!xfs_fs_writable(mp))
1573 return 0;
1574
1575 xfs_icsb_sync_counters(mp, 0);
1576
1577 /*
1578 * we don't need to do this if we are updating the superblock
1579 * counters on every modification.
1580 */
1581 if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
1582 return 0;
1583
1584 tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);
1585 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1586 XFS_DEFAULT_LOG_COUNT);
1587 if (error) {
1588 xfs_trans_cancel(tp, 0);
1589 return error;
1590 }
1591
1592 xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
1593 xfs_trans_set_sync(tp);
1594 error = xfs_trans_commit(tp, 0);
1595 return error;
1596}
1597
1598int
1599xfs_unmountfs_writesb(xfs_mount_t *mp)
1600{
1601 xfs_buf_t *sbp;
1602 int error = 0;
1603
1604 /*
1605 * skip superblock write if fs is read-only, or
1606 * if we are doing a forced umount.
1607 */
1608 if (!((mp->m_flags & XFS_MOUNT_RDONLY) ||
1609 XFS_FORCED_SHUTDOWN(mp))) {
1610
1611 sbp = xfs_getsb(mp, 0);
1612
1613 XFS_BUF_UNDONE(sbp);
1614 XFS_BUF_UNREAD(sbp);
1615 XFS_BUF_UNDELAYWRITE(sbp);
1616 XFS_BUF_WRITE(sbp);
1617 XFS_BUF_UNASYNC(sbp);
1618 ASSERT(sbp->b_target == mp->m_ddev_targp);
1619 xfsbdstrat(mp, sbp);
1620 error = xfs_buf_iowait(sbp);
1621 if (error)
1622 xfs_ioerror_alert("xfs_unmountfs_writesb",
1623 mp, sbp, XFS_BUF_ADDR(sbp));
1624 xfs_buf_relse(sbp);
1625 }
1626 return error;
1627}
1628
1629/*
1630 * xfs_mod_sb() can be used to copy arbitrary changes to the
1631 * in-core superblock into the superblock buffer to be logged.
1632 * It does not provide the higher level of locking that is
1633 * needed to protect the in-core superblock from concurrent
1634 * access.
1635 */
1636void
1637xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
1638{
1639 xfs_buf_t *bp;
1640 int first;
1641 int last;
1642 xfs_mount_t *mp;
1643 xfs_sb_field_t f;
1644
1645 ASSERT(fields);
1646 if (!fields)
1647 return;
1648 mp = tp->t_mountp;
1649 bp = xfs_trans_getsb(tp, mp, 0);
1650 first = sizeof(xfs_sb_t);
1651 last = 0;
1652
1653 /* translate/copy */
1654
1655 xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
1656
1657 /* find modified range */
1658 f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
1659 ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1660 last = xfs_sb_info[f + 1].offset - 1;
1661
1662 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
1663 ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1664 first = xfs_sb_info[f].offset;
1665
1666 xfs_trans_log_buf(tp, bp, first, last);
1667}
1668
1669
1670/*
1671 * xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
1672 * a delta to a specified field in the in-core superblock. Simply
1673 * switch on the field indicated and apply the delta to that field.
1674 * Fields are not allowed to dip below zero, so if the delta would
1675 * do this do not apply it and return EINVAL.
1676 *
1677 * The m_sb_lock must be held when this routine is called.
1678 */
1679STATIC int
1680xfs_mod_incore_sb_unlocked(
1681 xfs_mount_t *mp,
1682 xfs_sb_field_t field,
1683 int64_t delta,
1684 int rsvd)
1685{
1686 int scounter; /* short counter for 32 bit fields */
1687 long long lcounter; /* long counter for 64 bit fields */
1688 long long res_used, rem;
1689
1690 /*
1691 * With the in-core superblock spin lock held, switch
1692 * on the indicated field. Apply the delta to the
1693 * proper field. If the fields value would dip below
1694 * 0, then do not apply the delta and return EINVAL.
1695 */
1696 switch (field) {
1697 case XFS_SBS_ICOUNT:
1698 lcounter = (long long)mp->m_sb.sb_icount;
1699 lcounter += delta;
1700 if (lcounter < 0) {
1701 ASSERT(0);
1702 return XFS_ERROR(EINVAL);
1703 }
1704 mp->m_sb.sb_icount = lcounter;
1705 return 0;
1706 case XFS_SBS_IFREE:
1707 lcounter = (long long)mp->m_sb.sb_ifree;
1708 lcounter += delta;
1709 if (lcounter < 0) {
1710 ASSERT(0);
1711 return XFS_ERROR(EINVAL);
1712 }
1713 mp->m_sb.sb_ifree = lcounter;
1714 return 0;
1715 case XFS_SBS_FDBLOCKS:
1716 lcounter = (long long)
1717 mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
1718 res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
1719
1720 if (delta > 0) { /* Putting blocks back */
1721 if (res_used > delta) {
1722 mp->m_resblks_avail += delta;
1723 } else {
1724 rem = delta - res_used;
1725 mp->m_resblks_avail = mp->m_resblks;
1726 lcounter += rem;
1727 }
1728 } else { /* Taking blocks away */
1729 lcounter += delta;
1730 if (lcounter >= 0) {
1731 mp->m_sb.sb_fdblocks = lcounter +
1732 XFS_ALLOC_SET_ASIDE(mp);
1733 return 0;
1734 }
1735
1736 /*
1737 * We are out of blocks, use any available reserved
1738 * blocks if were allowed to.
1739 */
1740 if (!rsvd)
1741 return XFS_ERROR(ENOSPC);
1742
1743 lcounter = (long long)mp->m_resblks_avail + delta;
1744 if (lcounter >= 0) {
1745 mp->m_resblks_avail = lcounter;
1746 return 0;
1747 }
1748 printk_once(KERN_WARNING
1749 "Filesystem \"%s\": reserve blocks depleted! "
1750 "Consider increasing reserve pool size.",
1751 mp->m_fsname);
1752 return XFS_ERROR(ENOSPC);
1753 }
1754
1755 mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
1756 return 0;
1757 case XFS_SBS_FREXTENTS:
1758 lcounter = (long long)mp->m_sb.sb_frextents;
1759 lcounter += delta;
1760 if (lcounter < 0) {
1761 return XFS_ERROR(ENOSPC);
1762 }
1763 mp->m_sb.sb_frextents = lcounter;
1764 return 0;
1765 case XFS_SBS_DBLOCKS:
1766 lcounter = (long long)mp->m_sb.sb_dblocks;
1767 lcounter += delta;
1768 if (lcounter < 0) {
1769 ASSERT(0);
1770 return XFS_ERROR(EINVAL);
1771 }
1772 mp->m_sb.sb_dblocks = lcounter;
1773 return 0;
1774 case XFS_SBS_AGCOUNT:
1775 scounter = mp->m_sb.sb_agcount;
1776 scounter += delta;
1777 if (scounter < 0) {
1778 ASSERT(0);
1779 return XFS_ERROR(EINVAL);
1780 }
1781 mp->m_sb.sb_agcount = scounter;
1782 return 0;
1783 case XFS_SBS_IMAX_PCT:
1784 scounter = mp->m_sb.sb_imax_pct;
1785 scounter += delta;
1786 if (scounter < 0) {
1787 ASSERT(0);
1788 return XFS_ERROR(EINVAL);
1789 }
1790 mp->m_sb.sb_imax_pct = scounter;
1791 return 0;
1792 case XFS_SBS_REXTSIZE:
1793 scounter = mp->m_sb.sb_rextsize;
1794 scounter += delta;
1795 if (scounter < 0) {
1796 ASSERT(0);
1797 return XFS_ERROR(EINVAL);
1798 }
1799 mp->m_sb.sb_rextsize = scounter;
1800 return 0;
1801 case XFS_SBS_RBMBLOCKS:
1802 scounter = mp->m_sb.sb_rbmblocks;
1803 scounter += delta;
1804 if (scounter < 0) {
1805 ASSERT(0);
1806 return XFS_ERROR(EINVAL);
1807 }
1808 mp->m_sb.sb_rbmblocks = scounter;
1809 return 0;
1810 case XFS_SBS_RBLOCKS:
1811 lcounter = (long long)mp->m_sb.sb_rblocks;
1812 lcounter += delta;
1813 if (lcounter < 0) {
1814 ASSERT(0);
1815 return XFS_ERROR(EINVAL);
1816 }
1817 mp->m_sb.sb_rblocks = lcounter;
1818 return 0;
1819 case XFS_SBS_REXTENTS:
1820 lcounter = (long long)mp->m_sb.sb_rextents;
1821 lcounter += delta;
1822 if (lcounter < 0) {
1823 ASSERT(0);
1824 return XFS_ERROR(EINVAL);
1825 }
1826 mp->m_sb.sb_rextents = lcounter;
1827 return 0;
1828 case XFS_SBS_REXTSLOG:
1829 scounter = mp->m_sb.sb_rextslog;
1830 scounter += delta;
1831 if (scounter < 0) {
1832 ASSERT(0);
1833 return XFS_ERROR(EINVAL);
1834 }
1835 mp->m_sb.sb_rextslog = scounter;
1836 return 0;
1837 default:
1838 ASSERT(0);
1839 return XFS_ERROR(EINVAL);
1840 }
1841}
1842
1843/*
1844 * xfs_mod_incore_sb() is used to change a field in the in-core
1845 * superblock structure by the specified delta. This modification
1846 * is protected by the m_sb_lock. Just use the xfs_mod_incore_sb_unlocked()
1847 * routine to do the work.
1848 */
1849int
1850xfs_mod_incore_sb(
1851 struct xfs_mount *mp,
1852 xfs_sb_field_t field,
1853 int64_t delta,
1854 int rsvd)
1855{
1856 int status;
1857
1858#ifdef HAVE_PERCPU_SB
1859 ASSERT(field < XFS_SBS_ICOUNT || field > XFS_SBS_FDBLOCKS);
1860#endif
1861 spin_lock(&mp->m_sb_lock);
1862 status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
1863 spin_unlock(&mp->m_sb_lock);
1864
1865 return status;
1866}
1867
1868/*
1869 * Change more than one field in the in-core superblock structure at a time.
1870 *
1871 * The fields and changes to those fields are specified in the array of
1872 * xfs_mod_sb structures passed in. Either all of the specified deltas
1873 * will be applied or none of them will. If any modified field dips below 0,
1874 * then all modifications will be backed out and EINVAL will be returned.
1875 *
1876 * Note that this function may not be used for the superblock values that
1877 * are tracked with the in-memory per-cpu counters - a direct call to
1878 * xfs_icsb_modify_counters is required for these.
1879 */
1880int
1881xfs_mod_incore_sb_batch(
1882 struct xfs_mount *mp,
1883 xfs_mod_sb_t *msb,
1884 uint nmsb,
1885 int rsvd)
1886{
1887 xfs_mod_sb_t *msbp;
1888 int error = 0;
1889
1890 /*
1891 * Loop through the array of mod structures and apply each individually.
1892 * If any fail, then back out all those which have already been applied.
1893 * Do all of this within the scope of the m_sb_lock so that all of the
1894 * changes will be atomic.
1895 */
1896 spin_lock(&mp->m_sb_lock);
1897 for (msbp = msb; msbp < (msb + nmsb); msbp++) {
1898 ASSERT(msbp->msb_field < XFS_SBS_ICOUNT ||
1899 msbp->msb_field > XFS_SBS_FDBLOCKS);
1900
1901 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1902 msbp->msb_delta, rsvd);
1903 if (error)
1904 goto unwind;
1905 }
1906 spin_unlock(&mp->m_sb_lock);
1907 return 0;
1908
1909unwind:
1910 while (--msbp >= msb) {
1911 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1912 -msbp->msb_delta, rsvd);
1913 ASSERT(error == 0);
1914 }
1915 spin_unlock(&mp->m_sb_lock);
1916 return error;
1917}
1918
1919/*
1920 * xfs_getsb() is called to obtain the buffer for the superblock.
1921 * The buffer is returned locked and read in from disk.
1922 * The buffer should be released with a call to xfs_brelse().
1923 *
1924 * If the flags parameter is BUF_TRYLOCK, then we'll only return
1925 * the superblock buffer if it can be locked without sleeping.
1926 * If it can't then we'll return NULL.
1927 */
1928struct xfs_buf *
1929xfs_getsb(
1930 struct xfs_mount *mp,
1931 int flags)
1932{
1933 struct xfs_buf *bp = mp->m_sb_bp;
1934
1935 if (!xfs_buf_trylock(bp)) {
1936 if (flags & XBF_TRYLOCK)
1937 return NULL;
1938 xfs_buf_lock(bp);
1939 }
1940
1941 xfs_buf_hold(bp);
1942 ASSERT(XFS_BUF_ISDONE(bp));
1943 return bp;
1944}
1945
1946/*
1947 * Used to free the superblock along various error paths.
1948 */
1949void
1950xfs_freesb(
1951 struct xfs_mount *mp)
1952{
1953 struct xfs_buf *bp = mp->m_sb_bp;
1954
1955 xfs_buf_lock(bp);
1956 mp->m_sb_bp = NULL;
1957 xfs_buf_relse(bp);
1958}
1959
1960/*
1961 * Used to log changes to the superblock unit and width fields which could
1962 * be altered by the mount options, as well as any potential sb_features2
1963 * fixup. Only the first superblock is updated.
1964 */
1965int
1966xfs_mount_log_sb(
1967 xfs_mount_t *mp,
1968 __int64_t fields)
1969{
1970 xfs_trans_t *tp;
1971 int error;
1972
1973 ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
1974 XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2 |
1975 XFS_SB_VERSIONNUM));
1976
1977 tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
1978 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1979 XFS_DEFAULT_LOG_COUNT);
1980 if (error) {
1981 xfs_trans_cancel(tp, 0);
1982 return error;
1983 }
1984 xfs_mod_sb(tp, fields);
1985 error = xfs_trans_commit(tp, 0);
1986 return error;
1987}
1988
1989/*
1990 * If the underlying (data/log/rt) device is readonly, there are some
1991 * operations that cannot proceed.
1992 */
1993int
1994xfs_dev_is_read_only(
1995 struct xfs_mount *mp,
1996 char *message)
1997{
1998 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
1999 xfs_readonly_buftarg(mp->m_logdev_targp) ||
2000 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
2001 xfs_notice(mp, "%s required on read-only device.", message);
2002 xfs_notice(mp, "write access unavailable, cannot proceed.");
2003 return EROFS;
2004 }
2005 return 0;
2006}
2007
2008#ifdef HAVE_PERCPU_SB
2009/*
2010 * Per-cpu incore superblock counters
2011 *
2012 * Simple concept, difficult implementation
2013 *
2014 * Basically, replace the incore superblock counters with a distributed per cpu
2015 * counter for contended fields (e.g. free block count).
2016 *
2017 * Difficulties arise in that the incore sb is used for ENOSPC checking, and
2018 * hence needs to be accurately read when we are running low on space. Hence
2019 * there is a method to enable and disable the per-cpu counters based on how
2020 * much "stuff" is available in them.
2021 *
2022 * Basically, a counter is enabled if there is enough free resource to justify
2023 * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
2024 * ENOSPC), then we disable the counters to synchronise all callers and
2025 * re-distribute the available resources.
2026 *
2027 * If, once we redistributed the available resources, we still get a failure,
2028 * we disable the per-cpu counter and go through the slow path.
2029 *
2030 * The slow path is the current xfs_mod_incore_sb() function. This means that
2031 * when we disable a per-cpu counter, we need to drain its resources back to
2032 * the global superblock. We do this after disabling the counter to prevent
2033 * more threads from queueing up on the counter.
2034 *
2035 * Essentially, this means that we still need a lock in the fast path to enable
2036 * synchronisation between the global counters and the per-cpu counters. This
2037 * is not a problem because the lock will be local to a CPU almost all the time
2038 * and have little contention except when we get to ENOSPC conditions.
2039 *
2040 * Basically, this lock becomes a barrier that enables us to lock out the fast
2041 * path while we do things like enabling and disabling counters and
2042 * synchronising the counters.
2043 *
2044 * Locking rules:
2045 *
2046 * 1. m_sb_lock before picking up per-cpu locks
2047 * 2. per-cpu locks always picked up via for_each_online_cpu() order
2048 * 3. accurate counter sync requires m_sb_lock + per cpu locks
2049 * 4. modifying per-cpu counters requires holding per-cpu lock
2050 * 5. modifying global counters requires holding m_sb_lock
2051 * 6. enabling or disabling a counter requires holding the m_sb_lock
2052 * and _none_ of the per-cpu locks.
2053 *
2054 * Disabled counters are only ever re-enabled by a balance operation
2055 * that results in more free resources per CPU than a given threshold.
2056 * To ensure counters don't remain disabled, they are rebalanced when
2057 * the global resource goes above a higher threshold (i.e. some hysteresis
2058 * is present to prevent thrashing).
2059 */
2060
2061#ifdef CONFIG_HOTPLUG_CPU
2062/*
2063 * hot-plug CPU notifier support.
2064 *
2065 * We need a notifier per filesystem as we need to be able to identify
2066 * the filesystem to balance the counters out. This is achieved by
2067 * having a notifier block embedded in the xfs_mount_t and doing pointer
2068 * magic to get the mount pointer from the notifier block address.
2069 */
2070STATIC int
2071xfs_icsb_cpu_notify(
2072 struct notifier_block *nfb,
2073 unsigned long action,
2074 void *hcpu)
2075{
2076 xfs_icsb_cnts_t *cntp;
2077 xfs_mount_t *mp;
2078
2079 mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
2080 cntp = (xfs_icsb_cnts_t *)
2081 per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
2082 switch (action) {
2083 case CPU_UP_PREPARE:
2084 case CPU_UP_PREPARE_FROZEN:
2085 /* Easy Case - initialize the area and locks, and
2086 * then rebalance when online does everything else for us. */
2087 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2088 break;
2089 case CPU_ONLINE:
2090 case CPU_ONLINE_FROZEN:
2091 xfs_icsb_lock(mp);
2092 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
2093 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
2094 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
2095 xfs_icsb_unlock(mp);
2096 break;
2097 case CPU_DEAD:
2098 case CPU_DEAD_FROZEN:
2099 /* Disable all the counters, then fold the dead cpu's
2100 * count into the total on the global superblock and
2101 * re-enable the counters. */
2102 xfs_icsb_lock(mp);
2103 spin_lock(&mp->m_sb_lock);
2104 xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
2105 xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
2106 xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
2107
2108 mp->m_sb.sb_icount += cntp->icsb_icount;
2109 mp->m_sb.sb_ifree += cntp->icsb_ifree;
2110 mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
2111
2112 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2113
2114 xfs_icsb_balance_counter_locked(mp, XFS_SBS_ICOUNT, 0);
2115 xfs_icsb_balance_counter_locked(mp, XFS_SBS_IFREE, 0);
2116 xfs_icsb_balance_counter_locked(mp, XFS_SBS_FDBLOCKS, 0);
2117 spin_unlock(&mp->m_sb_lock);
2118 xfs_icsb_unlock(mp);
2119 break;
2120 }
2121
2122 return NOTIFY_OK;
2123}
2124#endif /* CONFIG_HOTPLUG_CPU */
2125
2126int
2127xfs_icsb_init_counters(
2128 xfs_mount_t *mp)
2129{
2130 xfs_icsb_cnts_t *cntp;
2131 int i;
2132
2133 mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
2134 if (mp->m_sb_cnts == NULL)
2135 return -ENOMEM;
2136
2137#ifdef CONFIG_HOTPLUG_CPU
2138 mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
2139 mp->m_icsb_notifier.priority = 0;
2140 register_hotcpu_notifier(&mp->m_icsb_notifier);
2141#endif /* CONFIG_HOTPLUG_CPU */
2142
2143 for_each_online_cpu(i) {
2144 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2145 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2146 }
2147
2148 mutex_init(&mp->m_icsb_mutex);
2149
2150 /*
2151 * start with all counters disabled so that the
2152 * initial balance kicks us off correctly
2153 */
2154 mp->m_icsb_counters = -1;
2155 return 0;
2156}
2157
2158void
2159xfs_icsb_reinit_counters(
2160 xfs_mount_t *mp)
2161{
2162 xfs_icsb_lock(mp);
2163 /*
2164 * start with all counters disabled so that the
2165 * initial balance kicks us off correctly
2166 */
2167 mp->m_icsb_counters = -1;
2168 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
2169 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
2170 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
2171 xfs_icsb_unlock(mp);
2172}
2173
2174void
2175xfs_icsb_destroy_counters(
2176 xfs_mount_t *mp)
2177{
2178 if (mp->m_sb_cnts) {
2179 unregister_hotcpu_notifier(&mp->m_icsb_notifier);
2180 free_percpu(mp->m_sb_cnts);
2181 }
2182 mutex_destroy(&mp->m_icsb_mutex);
2183}
2184
2185STATIC void
2186xfs_icsb_lock_cntr(
2187 xfs_icsb_cnts_t *icsbp)
2188{
2189 while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
2190 ndelay(1000);
2191 }
2192}
2193
2194STATIC void
2195xfs_icsb_unlock_cntr(
2196 xfs_icsb_cnts_t *icsbp)
2197{
2198 clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
2199}
2200
2201
2202STATIC void
2203xfs_icsb_lock_all_counters(
2204 xfs_mount_t *mp)
2205{
2206 xfs_icsb_cnts_t *cntp;
2207 int i;
2208
2209 for_each_online_cpu(i) {
2210 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2211 xfs_icsb_lock_cntr(cntp);
2212 }
2213}
2214
2215STATIC void
2216xfs_icsb_unlock_all_counters(
2217 xfs_mount_t *mp)
2218{
2219 xfs_icsb_cnts_t *cntp;
2220 int i;
2221
2222 for_each_online_cpu(i) {
2223 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2224 xfs_icsb_unlock_cntr(cntp);
2225 }
2226}
2227
2228STATIC void
2229xfs_icsb_count(
2230 xfs_mount_t *mp,
2231 xfs_icsb_cnts_t *cnt,
2232 int flags)
2233{
2234 xfs_icsb_cnts_t *cntp;
2235 int i;
2236
2237 memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
2238
2239 if (!(flags & XFS_ICSB_LAZY_COUNT))
2240 xfs_icsb_lock_all_counters(mp);
2241
2242 for_each_online_cpu(i) {
2243 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2244 cnt->icsb_icount += cntp->icsb_icount;
2245 cnt->icsb_ifree += cntp->icsb_ifree;
2246 cnt->icsb_fdblocks += cntp->icsb_fdblocks;
2247 }
2248
2249 if (!(flags & XFS_ICSB_LAZY_COUNT))
2250 xfs_icsb_unlock_all_counters(mp);
2251}
2252
2253STATIC int
2254xfs_icsb_counter_disabled(
2255 xfs_mount_t *mp,
2256 xfs_sb_field_t field)
2257{
2258 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2259 return test_bit(field, &mp->m_icsb_counters);
2260}
2261
2262STATIC void
2263xfs_icsb_disable_counter(
2264 xfs_mount_t *mp,
2265 xfs_sb_field_t field)
2266{
2267 xfs_icsb_cnts_t cnt;
2268
2269 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2270
2271 /*
2272 * If we are already disabled, then there is nothing to do
2273 * here. We check before locking all the counters to avoid
2274 * the expensive lock operation when being called in the
2275 * slow path and the counter is already disabled. This is
2276 * safe because the only time we set or clear this state is under
2277 * the m_icsb_mutex.
2278 */
2279 if (xfs_icsb_counter_disabled(mp, field))
2280 return;
2281
2282 xfs_icsb_lock_all_counters(mp);
2283 if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
2284 /* drain back to superblock */
2285
2286 xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
2287 switch(field) {
2288 case XFS_SBS_ICOUNT:
2289 mp->m_sb.sb_icount = cnt.icsb_icount;
2290 break;
2291 case XFS_SBS_IFREE:
2292 mp->m_sb.sb_ifree = cnt.icsb_ifree;
2293 break;
2294 case XFS_SBS_FDBLOCKS:
2295 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
2296 break;
2297 default:
2298 BUG();
2299 }
2300 }
2301
2302 xfs_icsb_unlock_all_counters(mp);
2303}
2304
2305STATIC void
2306xfs_icsb_enable_counter(
2307 xfs_mount_t *mp,
2308 xfs_sb_field_t field,
2309 uint64_t count,
2310 uint64_t resid)
2311{
2312 xfs_icsb_cnts_t *cntp;
2313 int i;
2314
2315 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2316
2317 xfs_icsb_lock_all_counters(mp);
2318 for_each_online_cpu(i) {
2319 cntp = per_cpu_ptr(mp->m_sb_cnts, i);
2320 switch (field) {
2321 case XFS_SBS_ICOUNT:
2322 cntp->icsb_icount = count + resid;
2323 break;
2324 case XFS_SBS_IFREE:
2325 cntp->icsb_ifree = count + resid;
2326 break;
2327 case XFS_SBS_FDBLOCKS:
2328 cntp->icsb_fdblocks = count + resid;
2329 break;
2330 default:
2331 BUG();
2332 break;
2333 }
2334 resid = 0;
2335 }
2336 clear_bit(field, &mp->m_icsb_counters);
2337 xfs_icsb_unlock_all_counters(mp);
2338}
2339
2340void
2341xfs_icsb_sync_counters_locked(
2342 xfs_mount_t *mp,
2343 int flags)
2344{
2345 xfs_icsb_cnts_t cnt;
2346
2347 xfs_icsb_count(mp, &cnt, flags);
2348
2349 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
2350 mp->m_sb.sb_icount = cnt.icsb_icount;
2351 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
2352 mp->m_sb.sb_ifree = cnt.icsb_ifree;
2353 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
2354 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
2355}
2356
2357/*
2358 * Accurate update of per-cpu counters to incore superblock
2359 */
2360void
2361xfs_icsb_sync_counters(
2362 xfs_mount_t *mp,
2363 int flags)
2364{
2365 spin_lock(&mp->m_sb_lock);
2366 xfs_icsb_sync_counters_locked(mp, flags);
2367 spin_unlock(&mp->m_sb_lock);
2368}
2369
2370/*
2371 * Balance and enable/disable counters as necessary.
2372 *
2373 * Thresholds for re-enabling counters are somewhat magic. inode counts are
2374 * chosen to be the same number as single on disk allocation chunk per CPU, and
2375 * free blocks is something far enough zero that we aren't going thrash when we
2376 * get near ENOSPC. We also need to supply a minimum we require per cpu to
2377 * prevent looping endlessly when xfs_alloc_space asks for more than will
2378 * be distributed to a single CPU but each CPU has enough blocks to be
2379 * reenabled.
2380 *
2381 * Note that we can be called when counters are already disabled.
2382 * xfs_icsb_disable_counter() optimises the counter locking in this case to
2383 * prevent locking every per-cpu counter needlessly.
2384 */
2385
2386#define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
2387#define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
2388 (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
2389STATIC void
2390xfs_icsb_balance_counter_locked(
2391 xfs_mount_t *mp,
2392 xfs_sb_field_t field,
2393 int min_per_cpu)
2394{
2395 uint64_t count, resid;
2396 int weight = num_online_cpus();
2397 uint64_t min = (uint64_t)min_per_cpu;
2398
2399 /* disable counter and sync counter */
2400 xfs_icsb_disable_counter(mp, field);
2401
2402 /* update counters - first CPU gets residual*/
2403 switch (field) {
2404 case XFS_SBS_ICOUNT:
2405 count = mp->m_sb.sb_icount;
2406 resid = do_div(count, weight);
2407 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
2408 return;
2409 break;
2410 case XFS_SBS_IFREE:
2411 count = mp->m_sb.sb_ifree;
2412 resid = do_div(count, weight);
2413 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
2414 return;
2415 break;
2416 case XFS_SBS_FDBLOCKS:
2417 count = mp->m_sb.sb_fdblocks;
2418 resid = do_div(count, weight);
2419 if (count < max(min, XFS_ICSB_FDBLK_CNTR_REENABLE(mp)))
2420 return;
2421 break;
2422 default:
2423 BUG();
2424 count = resid = 0; /* quiet, gcc */
2425 break;
2426 }
2427
2428 xfs_icsb_enable_counter(mp, field, count, resid);
2429}
2430
2431STATIC void
2432xfs_icsb_balance_counter(
2433 xfs_mount_t *mp,
2434 xfs_sb_field_t fields,
2435 int min_per_cpu)
2436{
2437 spin_lock(&mp->m_sb_lock);
2438 xfs_icsb_balance_counter_locked(mp, fields, min_per_cpu);
2439 spin_unlock(&mp->m_sb_lock);
2440}
2441
2442int
2443xfs_icsb_modify_counters(
2444 xfs_mount_t *mp,
2445 xfs_sb_field_t field,
2446 int64_t delta,
2447 int rsvd)
2448{
2449 xfs_icsb_cnts_t *icsbp;
2450 long long lcounter; /* long counter for 64 bit fields */
2451 int ret = 0;
2452
2453 might_sleep();
2454again:
2455 preempt_disable();
2456 icsbp = this_cpu_ptr(mp->m_sb_cnts);
2457
2458 /*
2459 * if the counter is disabled, go to slow path
2460 */
2461 if (unlikely(xfs_icsb_counter_disabled(mp, field)))
2462 goto slow_path;
2463 xfs_icsb_lock_cntr(icsbp);
2464 if (unlikely(xfs_icsb_counter_disabled(mp, field))) {
2465 xfs_icsb_unlock_cntr(icsbp);
2466 goto slow_path;
2467 }
2468
2469 switch (field) {
2470 case XFS_SBS_ICOUNT:
2471 lcounter = icsbp->icsb_icount;
2472 lcounter += delta;
2473 if (unlikely(lcounter < 0))
2474 goto balance_counter;
2475 icsbp->icsb_icount = lcounter;
2476 break;
2477
2478 case XFS_SBS_IFREE:
2479 lcounter = icsbp->icsb_ifree;
2480 lcounter += delta;
2481 if (unlikely(lcounter < 0))
2482 goto balance_counter;
2483 icsbp->icsb_ifree = lcounter;
2484 break;
2485
2486 case XFS_SBS_FDBLOCKS:
2487 BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
2488
2489 lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
2490 lcounter += delta;
2491 if (unlikely(lcounter < 0))
2492 goto balance_counter;
2493 icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
2494 break;
2495 default:
2496 BUG();
2497 break;
2498 }
2499 xfs_icsb_unlock_cntr(icsbp);
2500 preempt_enable();
2501 return 0;
2502
2503slow_path:
2504 preempt_enable();
2505
2506 /*
2507 * serialise with a mutex so we don't burn lots of cpu on
2508 * the superblock lock. We still need to hold the superblock
2509 * lock, however, when we modify the global structures.
2510 */
2511 xfs_icsb_lock(mp);
2512
2513 /*
2514 * Now running atomically.
2515 *
2516 * If the counter is enabled, someone has beaten us to rebalancing.
2517 * Drop the lock and try again in the fast path....
2518 */
2519 if (!(xfs_icsb_counter_disabled(mp, field))) {
2520 xfs_icsb_unlock(mp);
2521 goto again;
2522 }
2523
2524 /*
2525 * The counter is currently disabled. Because we are
2526 * running atomically here, we know a rebalance cannot
2527 * be in progress. Hence we can go straight to operating
2528 * on the global superblock. We do not call xfs_mod_incore_sb()
2529 * here even though we need to get the m_sb_lock. Doing so
2530 * will cause us to re-enter this function and deadlock.
2531 * Hence we get the m_sb_lock ourselves and then call
2532 * xfs_mod_incore_sb_unlocked() as the unlocked path operates
2533 * directly on the global counters.
2534 */
2535 spin_lock(&mp->m_sb_lock);
2536 ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
2537 spin_unlock(&mp->m_sb_lock);
2538
2539 /*
2540 * Now that we've modified the global superblock, we
2541 * may be able to re-enable the distributed counters
2542 * (e.g. lots of space just got freed). After that
2543 * we are done.
2544 */
2545 if (ret != ENOSPC)
2546 xfs_icsb_balance_counter(mp, field, 0);
2547 xfs_icsb_unlock(mp);
2548 return ret;
2549
2550balance_counter:
2551 xfs_icsb_unlock_cntr(icsbp);
2552 preempt_enable();
2553
2554 /*
2555 * We may have multiple threads here if multiple per-cpu
2556 * counters run dry at the same time. This will mean we can
2557 * do more balances than strictly necessary but it is not
2558 * the common slowpath case.
2559 */
2560 xfs_icsb_lock(mp);
2561
2562 /*
2563 * running atomically.
2564 *
2565 * This will leave the counter in the correct state for future
2566 * accesses. After the rebalance, we simply try again and our retry
2567 * will either succeed through the fast path or slow path without
2568 * another balance operation being required.
2569 */
2570 xfs_icsb_balance_counter(mp, field, delta);
2571 xfs_icsb_unlock(mp);
2572 goto again;
2573}
2574
2575#endif