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

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