1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_sb.h"
13#include "xfs_mount.h"
14#include "xfs_trans.h"
15#include "xfs_error.h"
16#include "xfs_alloc.h"
17#include "xfs_fsops.h"
18#include "xfs_trans_space.h"
19#include "xfs_log.h"
20#include "xfs_log_priv.h"
21#include "xfs_ag.h"
22#include "xfs_ag_resv.h"
23#include "xfs_trace.h"
24
25/*
26 * Write new AG headers to disk. Non-transactional, but need to be
27 * written and completed prior to the growfs transaction being logged.
28 * To do this, we use a delayed write buffer list and wait for
29 * submission and IO completion of the list as a whole. This allows the
30 * IO subsystem to merge all the AG headers in a single AG into a single
31 * IO and hide most of the latency of the IO from us.
32 *
33 * This also means that if we get an error whilst building the buffer
34 * list to write, we can cancel the entire list without having written
35 * anything.
36 */
37static int
38xfs_resizefs_init_new_ags(
39 struct xfs_trans *tp,
40 struct aghdr_init_data *id,
41 xfs_agnumber_t oagcount,
42 xfs_agnumber_t nagcount,
43 xfs_rfsblock_t delta,
44 struct xfs_perag *last_pag,
45 bool *lastag_extended)
46{
47 struct xfs_mount *mp = tp->t_mountp;
48 xfs_rfsblock_t nb = mp->m_sb.sb_dblocks + delta;
49 int error;
50
51 *lastag_extended = false;
52
53 INIT_LIST_HEAD(list: &id->buffer_list);
54 for (id->agno = nagcount - 1;
55 id->agno >= oagcount;
56 id->agno--, delta -= id->agsize) {
57
58 if (id->agno == nagcount - 1)
59 id->agsize = nb - (id->agno *
60 (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
61 else
62 id->agsize = mp->m_sb.sb_agblocks;
63
64 error = xfs_ag_init_headers(mp, id);
65 if (error) {
66 xfs_buf_delwri_cancel(&id->buffer_list);
67 return error;
68 }
69 }
70
71 error = xfs_buf_delwri_submit(&id->buffer_list);
72 if (error)
73 return error;
74
75 if (delta) {
76 *lastag_extended = true;
77 error = xfs_ag_extend_space(last_pag, tp, delta);
78 }
79 return error;
80}
81
82/*
83 * growfs operations
84 */
85static int
86xfs_growfs_data_private(
87 struct xfs_mount *mp, /* mount point for filesystem */
88 struct xfs_growfs_data *in) /* growfs data input struct */
89{
90 struct xfs_buf *bp;
91 int error;
92 xfs_agnumber_t nagcount;
93 xfs_agnumber_t nagimax = 0;
94 xfs_rfsblock_t nb, nb_div, nb_mod;
95 int64_t delta;
96 bool lastag_extended = false;
97 xfs_agnumber_t oagcount;
98 struct xfs_trans *tp;
99 struct aghdr_init_data id = {};
100 struct xfs_perag *last_pag;
101
102 nb = in->newblocks;
103 error = xfs_sb_validate_fsb_count(&mp->m_sb, nb);
104 if (error)
105 return error;
106
107 if (nb > mp->m_sb.sb_dblocks) {
108 error = xfs_buf_read_uncached(mp->m_ddev_targp,
109 XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
110 XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
111 if (error)
112 return error;
113 xfs_buf_relse(bp);
114 }
115
116 nb_div = nb;
117 nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
118 if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS)
119 nb_div++;
120 else if (nb_mod)
121 nb = nb_div * mp->m_sb.sb_agblocks;
122
123 if (nb_div > XFS_MAX_AGNUMBER + 1) {
124 nb_div = XFS_MAX_AGNUMBER + 1;
125 nb = nb_div * mp->m_sb.sb_agblocks;
126 }
127 nagcount = nb_div;
128 delta = nb - mp->m_sb.sb_dblocks;
129 /*
130 * Reject filesystems with a single AG because they are not
131 * supported, and reject a shrink operation that would cause a
132 * filesystem to become unsupported.
133 */
134 if (delta < 0 && nagcount < 2)
135 return -EINVAL;
136
137 oagcount = mp->m_sb.sb_agcount;
138 /* allocate the new per-ag structures */
139 if (nagcount > oagcount) {
140 error = xfs_initialize_perag(mp, nagcount, nb, &nagimax);
141 if (error)
142 return error;
143 } else if (nagcount < oagcount) {
144 /* TODO: shrinking the entire AGs hasn't yet completed */
145 return -EINVAL;
146 }
147
148 if (delta > 0)
149 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
150 XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE,
151 &tp);
152 else
153 error = xfs_trans_alloc(mp, resp: &M_RES(mp)->tr_growdata, blocks: -delta, rtextents: 0,
154 flags: 0, tpp: &tp);
155 if (error)
156 return error;
157
158 last_pag = xfs_perag_get(mp, oagcount - 1);
159 if (delta > 0) {
160 error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount,
161 delta, last_pag, &lastag_extended);
162 } else {
163 xfs_warn_mount(mp, XFS_OPSTATE_WARNED_SHRINK,
164 "EXPERIMENTAL online shrink feature in use. Use at your own risk!");
165
166 error = xfs_ag_shrink_space(last_pag, &tp, -delta);
167 }
168 xfs_perag_put(last_pag);
169 if (error)
170 goto out_trans_cancel;
171
172 /*
173 * Update changed superblock fields transactionally. These are not
174 * seen by the rest of the world until the transaction commit applies
175 * them atomically to the superblock.
176 */
177 if (nagcount > oagcount)
178 xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
179 if (delta)
180 xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS, delta);
181 if (id.nfree)
182 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
183
184 /*
185 * Sync sb counters now to reflect the updated values. This is
186 * particularly important for shrink because the write verifier
187 * will fail if sb_fdblocks is ever larger than sb_dblocks.
188 */
189 if (xfs_has_lazysbcount(mp))
190 xfs_log_sb(tp);
191
192 xfs_trans_set_sync(tp);
193 error = xfs_trans_commit(tp);
194 if (error)
195 return error;
196
197 /* New allocation groups fully initialized, so update mount struct */
198 if (nagimax)
199 mp->m_maxagi = nagimax;
200 xfs_set_low_space_thresholds(mp);
201 mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
202
203 if (delta > 0) {
204 /*
205 * If we expanded the last AG, free the per-AG reservation
206 * so we can reinitialize it with the new size.
207 */
208 if (lastag_extended) {
209 struct xfs_perag *pag;
210
211 pag = xfs_perag_get(mp, id.agno);
212 error = xfs_ag_resv_free(pag);
213 xfs_perag_put(pag);
214 if (error)
215 return error;
216 }
217 /*
218 * Reserve AG metadata blocks. ENOSPC here does not mean there
219 * was a growfs failure, just that there still isn't space for
220 * new user data after the grow has been run.
221 */
222 error = xfs_fs_reserve_ag_blocks(mp);
223 if (error == -ENOSPC)
224 error = 0;
225 }
226 return error;
227
228out_trans_cancel:
229 xfs_trans_cancel(tp);
230 return error;
231}
232
233static int
234xfs_growfs_log_private(
235 struct xfs_mount *mp, /* mount point for filesystem */
236 struct xfs_growfs_log *in) /* growfs log input struct */
237{
238 xfs_extlen_t nb;
239
240 nb = in->newblocks;
241 if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
242 return -EINVAL;
243 if (nb == mp->m_sb.sb_logblocks &&
244 in->isint == (mp->m_sb.sb_logstart != 0))
245 return -EINVAL;
246 /*
247 * Moving the log is hard, need new interfaces to sync
248 * the log first, hold off all activity while moving it.
249 * Can have shorter or longer log in the same space,
250 * or transform internal to external log or vice versa.
251 */
252 return -ENOSYS;
253}
254
255static int
256xfs_growfs_imaxpct(
257 struct xfs_mount *mp,
258 __u32 imaxpct)
259{
260 struct xfs_trans *tp;
261 int dpct;
262 int error;
263
264 if (imaxpct > 100)
265 return -EINVAL;
266
267 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
268 XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
269 if (error)
270 return error;
271
272 dpct = imaxpct - mp->m_sb.sb_imax_pct;
273 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
274 xfs_trans_set_sync(tp);
275 return xfs_trans_commit(tp);
276}
277
278/*
279 * protected versions of growfs function acquire and release locks on the mount
280 * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
281 * XFS_IOC_FSGROWFSRT
282 */
283int
284xfs_growfs_data(
285 struct xfs_mount *mp,
286 struct xfs_growfs_data *in)
287{
288 int error = 0;
289
290 if (!capable(CAP_SYS_ADMIN))
291 return -EPERM;
292 if (!mutex_trylock(lock: &mp->m_growlock))
293 return -EWOULDBLOCK;
294
295 /* update imaxpct separately to the physical grow of the filesystem */
296 if (in->imaxpct != mp->m_sb.sb_imax_pct) {
297 error = xfs_growfs_imaxpct(mp, imaxpct: in->imaxpct);
298 if (error)
299 goto out_error;
300 }
301
302 if (in->newblocks != mp->m_sb.sb_dblocks) {
303 error = xfs_growfs_data_private(mp, in);
304 if (error)
305 goto out_error;
306 }
307
308 /* Post growfs calculations needed to reflect new state in operations */
309 if (mp->m_sb.sb_imax_pct) {
310 uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
311 do_div(icount, 100);
312 M_IGEO(mp)->maxicount = XFS_FSB_TO_INO(mp, icount);
313 } else
314 M_IGEO(mp)->maxicount = 0;
315
316 /* Update secondary superblocks now the physical grow has completed */
317 error = xfs_update_secondary_sbs(mp);
318
319out_error:
320 /*
321 * Increment the generation unconditionally, the error could be from
322 * updating the secondary superblocks, in which case the new size
323 * is live already.
324 */
325 mp->m_generation++;
326 mutex_unlock(lock: &mp->m_growlock);
327 return error;
328}
329
330int
331xfs_growfs_log(
332 xfs_mount_t *mp,
333 struct xfs_growfs_log *in)
334{
335 int error;
336
337 if (!capable(CAP_SYS_ADMIN))
338 return -EPERM;
339 if (!mutex_trylock(lock: &mp->m_growlock))
340 return -EWOULDBLOCK;
341 error = xfs_growfs_log_private(mp, in);
342 mutex_unlock(lock: &mp->m_growlock);
343 return error;
344}
345
346/*
347 * exported through ioctl XFS_IOC_FSCOUNTS
348 */
349
350void
351xfs_fs_counts(
352 xfs_mount_t *mp,
353 xfs_fsop_counts_t *cnt)
354{
355 cnt->allocino = percpu_counter_read_positive(fbc: &mp->m_icount);
356 cnt->freeino = percpu_counter_read_positive(fbc: &mp->m_ifree);
357 cnt->freedata = percpu_counter_read_positive(fbc: &mp->m_fdblocks) -
358 xfs_fdblocks_unavailable(mp);
359 cnt->freertx = percpu_counter_read_positive(fbc: &mp->m_frextents);
360}
361
362/*
363 * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
364 *
365 * xfs_reserve_blocks is called to set m_resblks
366 * in the in-core mount table. The number of unused reserved blocks
367 * is kept in m_resblks_avail.
368 *
369 * Reserve the requested number of blocks if available. Otherwise return
370 * as many as possible to satisfy the request. The actual number
371 * reserved are returned in outval
372 *
373 * A null inval pointer indicates that only the current reserved blocks
374 * available should be returned no settings are changed.
375 */
376
377int
378xfs_reserve_blocks(
379 xfs_mount_t *mp,
380 uint64_t *inval,
381 xfs_fsop_resblks_t *outval)
382{
383 int64_t lcounter, delta;
384 int64_t fdblks_delta = 0;
385 uint64_t request;
386 int64_t free;
387 int error = 0;
388
389 /* If inval is null, report current values and return */
390 if (inval == (uint64_t *)NULL) {
391 if (!outval)
392 return -EINVAL;
393 outval->resblks = mp->m_resblks;
394 outval->resblks_avail = mp->m_resblks_avail;
395 return 0;
396 }
397
398 request = *inval;
399
400 /*
401 * With per-cpu counters, this becomes an interesting problem. we need
402 * to work out if we are freeing or allocation blocks first, then we can
403 * do the modification as necessary.
404 *
405 * We do this under the m_sb_lock so that if we are near ENOSPC, we will
406 * hold out any changes while we work out what to do. This means that
407 * the amount of free space can change while we do this, so we need to
408 * retry if we end up trying to reserve more space than is available.
409 */
410 spin_lock(lock: &mp->m_sb_lock);
411
412 /*
413 * If our previous reservation was larger than the current value,
414 * then move any unused blocks back to the free pool. Modify the resblks
415 * counters directly since we shouldn't have any problems unreserving
416 * space.
417 */
418 if (mp->m_resblks > request) {
419 lcounter = mp->m_resblks_avail - request;
420 if (lcounter > 0) { /* release unused blocks */
421 fdblks_delta = lcounter;
422 mp->m_resblks_avail -= lcounter;
423 }
424 mp->m_resblks = request;
425 if (fdblks_delta) {
426 spin_unlock(lock: &mp->m_sb_lock);
427 error = xfs_mod_fdblocks(mp, delta: fdblks_delta, reserved: 0);
428 spin_lock(lock: &mp->m_sb_lock);
429 }
430
431 goto out;
432 }
433
434 /*
435 * If the request is larger than the current reservation, reserve the
436 * blocks before we update the reserve counters. Sample m_fdblocks and
437 * perform a partial reservation if the request exceeds free space.
438 *
439 * The code below estimates how many blocks it can request from
440 * fdblocks to stash in the reserve pool. This is a classic TOCTOU
441 * race since fdblocks updates are not always coordinated via
442 * m_sb_lock. Set the reserve size even if there's not enough free
443 * space to fill it because mod_fdblocks will refill an undersized
444 * reserve when it can.
445 */
446 free = percpu_counter_sum(fbc: &mp->m_fdblocks) -
447 xfs_fdblocks_unavailable(mp);
448 delta = request - mp->m_resblks;
449 mp->m_resblks = request;
450 if (delta > 0 && free > 0) {
451 /*
452 * We'll either succeed in getting space from the free block
453 * count or we'll get an ENOSPC. Don't set the reserved flag
454 * here - we don't want to reserve the extra reserve blocks
455 * from the reserve.
456 *
457 * The desired reserve size can change after we drop the lock.
458 * Use mod_fdblocks to put the space into the reserve or into
459 * fdblocks as appropriate.
460 */
461 fdblks_delta = min(free, delta);
462 spin_unlock(lock: &mp->m_sb_lock);
463 error = xfs_mod_fdblocks(mp, delta: -fdblks_delta, reserved: 0);
464 if (!error)
465 xfs_mod_fdblocks(mp, delta: fdblks_delta, reserved: 0);
466 spin_lock(lock: &mp->m_sb_lock);
467 }
468out:
469 if (outval) {
470 outval->resblks = mp->m_resblks;
471 outval->resblks_avail = mp->m_resblks_avail;
472 }
473
474 spin_unlock(lock: &mp->m_sb_lock);
475 return error;
476}
477
478int
479xfs_fs_goingdown(
480 xfs_mount_t *mp,
481 uint32_t inflags)
482{
483 switch (inflags) {
484 case XFS_FSOP_GOING_FLAGS_DEFAULT: {
485 if (!freeze_bdev(bdev: mp->m_super->s_bdev)) {
486 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
487 thaw_bdev(bdev: mp->m_super->s_bdev);
488 }
489 break;
490 }
491 case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
492 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
493 break;
494 case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
495 xfs_force_shutdown(mp,
496 SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
497 break;
498 default:
499 return -EINVAL;
500 }
501
502 return 0;
503}
504
505/*
506 * Force a shutdown of the filesystem instantly while keeping the filesystem
507 * consistent. We don't do an unmount here; just shutdown the shop, make sure
508 * that absolutely nothing persistent happens to this filesystem after this
509 * point.
510 *
511 * The shutdown state change is atomic, resulting in the first and only the
512 * first shutdown call processing the shutdown. This means we only shutdown the
513 * log once as it requires, and we don't spam the logs when multiple concurrent
514 * shutdowns race to set the shutdown flags.
515 */
516void
517xfs_do_force_shutdown(
518 struct xfs_mount *mp,
519 uint32_t flags,
520 char *fname,
521 int lnnum)
522{
523 int tag;
524 const char *why;
525
526
527 if (test_and_set_bit(XFS_OPSTATE_SHUTDOWN, addr: &mp->m_opstate)) {
528 xlog_shutdown_wait(log: mp->m_log);
529 return;
530 }
531 if (mp->m_sb_bp)
532 mp->m_sb_bp->b_flags |= XBF_DONE;
533
534 if (flags & SHUTDOWN_FORCE_UMOUNT)
535 xfs_alert(mp, "User initiated shutdown received.");
536
537 if (xlog_force_shutdown(log: mp->m_log, shutdown_flags: flags)) {
538 tag = XFS_PTAG_SHUTDOWN_LOGERROR;
539 why = "Log I/O Error";
540 } else if (flags & SHUTDOWN_CORRUPT_INCORE) {
541 tag = XFS_PTAG_SHUTDOWN_CORRUPT;
542 why = "Corruption of in-memory data";
543 } else if (flags & SHUTDOWN_CORRUPT_ONDISK) {
544 tag = XFS_PTAG_SHUTDOWN_CORRUPT;
545 why = "Corruption of on-disk metadata";
546 } else if (flags & SHUTDOWN_DEVICE_REMOVED) {
547 tag = XFS_PTAG_SHUTDOWN_IOERROR;
548 why = "Block device removal";
549 } else {
550 tag = XFS_PTAG_SHUTDOWN_IOERROR;
551 why = "Metadata I/O Error";
552 }
553
554 trace_xfs_force_shutdown(mp, ptag: tag, flags, fname, line_num: lnnum);
555
556 xfs_alert_tag(mp, tag,
557"%s (0x%x) detected at %pS (%s:%d). Shutting down filesystem.",
558 why, flags, __return_address, fname, lnnum);
559 xfs_alert(mp,
560 "Please unmount the filesystem and rectify the problem(s)");
561 if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
562 xfs_stack_trace();
563}
564
565/*
566 * Reserve free space for per-AG metadata.
567 */
568int
569xfs_fs_reserve_ag_blocks(
570 struct xfs_mount *mp)
571{
572 xfs_agnumber_t agno;
573 struct xfs_perag *pag;
574 int error = 0;
575 int err2;
576
577 mp->m_finobt_nores = false;
578 for_each_perag(mp, agno, pag) {
579 err2 = xfs_ag_resv_init(pag, NULL);
580 if (err2 && !error)
581 error = err2;
582 }
583
584 if (error && error != -ENOSPC) {
585 xfs_warn(mp,
586 "Error %d reserving per-AG metadata reserve pool.", error);
587 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
588 }
589
590 return error;
591}
592
593/*
594 * Free space reserved for per-AG metadata.
595 */
596int
597xfs_fs_unreserve_ag_blocks(
598 struct xfs_mount *mp)
599{
600 xfs_agnumber_t agno;
601 struct xfs_perag *pag;
602 int error = 0;
603 int err2;
604
605 for_each_perag(mp, agno, pag) {
606 err2 = xfs_ag_resv_free(pag);
607 if (err2 && !error)
608 error = err2;
609 }
610
611 if (error)
612 xfs_warn(mp,
613 "Error %d freeing per-AG metadata reserve pool.", error);
614
615 return error;
616}
617

source code of linux/fs/xfs/xfs_fsops.c