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 */
37 static int
38 xfs_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(&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 */
85 static int
86 xfs_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 /* No work to do */
138 if (delta == 0)
139 return 0;
140
141 oagcount = mp->m_sb.sb_agcount;
142 /* allocate the new per-ag structures */
143 if (nagcount > oagcount) {
144 error = xfs_initialize_perag(mp, nagcount, nb, &nagimax);
145 if (error)
146 return error;
147 } else if (nagcount < oagcount) {
148 /* TODO: shrinking the entire AGs hasn't yet completed */
149 return -EINVAL;
150 }
151
152 if (delta > 0)
153 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
154 XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE,
155 &tp);
156 else
157 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata, -delta, 0,
158 0, &tp);
159 if (error)
160 goto out_free_unused_perag;
161
162 last_pag = xfs_perag_get(mp, oagcount - 1);
163 if (delta > 0) {
164 error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount,
165 delta, last_pag, &lastag_extended);
166 } else {
167 xfs_warn_mount(mp, XFS_OPSTATE_WARNED_SHRINK,
168 "EXPERIMENTAL online shrink feature in use. Use at your own risk!");
169
170 error = xfs_ag_shrink_space(last_pag, &tp, -delta);
171 }
172 xfs_perag_put(last_pag);
173 if (error)
174 goto out_trans_cancel;
175
176 /*
177 * Update changed superblock fields transactionally. These are not
178 * seen by the rest of the world until the transaction commit applies
179 * them atomically to the superblock.
180 */
181 if (nagcount > oagcount)
182 xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
183 if (delta)
184 xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS, delta);
185 if (id.nfree)
186 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
187
188 /*
189 * Sync sb counters now to reflect the updated values. This is
190 * particularly important for shrink because the write verifier
191 * will fail if sb_fdblocks is ever larger than sb_dblocks.
192 */
193 if (xfs_has_lazysbcount(mp))
194 xfs_log_sb(tp);
195
196 xfs_trans_set_sync(tp);
197 error = xfs_trans_commit(tp);
198 if (error)
199 return error;
200
201 /* New allocation groups fully initialized, so update mount struct */
202 if (nagimax)
203 mp->m_maxagi = nagimax;
204 xfs_set_low_space_thresholds(mp);
205 mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
206
207 if (delta > 0) {
208 /*
209 * If we expanded the last AG, free the per-AG reservation
210 * so we can reinitialize it with the new size.
211 */
212 if (lastag_extended) {
213 struct xfs_perag *pag;
214
215 pag = xfs_perag_get(mp, id.agno);
216 xfs_ag_resv_free(pag);
217 xfs_perag_put(pag);
218 }
219 /*
220 * Reserve AG metadata blocks. ENOSPC here does not mean there
221 * was a growfs failure, just that there still isn't space for
222 * new user data after the grow has been run.
223 */
224 error = xfs_fs_reserve_ag_blocks(mp);
225 if (error == -ENOSPC)
226 error = 0;
227 }
228 return error;
229
230 out_trans_cancel:
231 xfs_trans_cancel(tp);
232 out_free_unused_perag:
233 if (nagcount > oagcount)
234 xfs_free_unused_perag_range(mp, oagcount, nagcount);
235 return error;
236 }
237
238 static int
239 xfs_growfs_log_private(
240 struct xfs_mount *mp, /* mount point for filesystem */
241 struct xfs_growfs_log *in) /* growfs log input struct */
242 {
243 xfs_extlen_t nb;
244
245 nb = in->newblocks;
246 if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
247 return -EINVAL;
248 if (nb == mp->m_sb.sb_logblocks &&
249 in->isint == (mp->m_sb.sb_logstart != 0))
250 return -EINVAL;
251 /*
252 * Moving the log is hard, need new interfaces to sync
253 * the log first, hold off all activity while moving it.
254 * Can have shorter or longer log in the same space,
255 * or transform internal to external log or vice versa.
256 */
257 return -ENOSYS;
258 }
259
260 static int
261 xfs_growfs_imaxpct(
262 struct xfs_mount *mp,
263 __u32 imaxpct)
264 {
265 struct xfs_trans *tp;
266 int dpct;
267 int error;
268
269 if (imaxpct > 100)
270 return -EINVAL;
271
272 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
273 XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
274 if (error)
275 return error;
276
277 dpct = imaxpct - mp->m_sb.sb_imax_pct;
278 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
279 xfs_trans_set_sync(tp);
280 return xfs_trans_commit(tp);
281 }
282
283 /*
284 * protected versions of growfs function acquire and release locks on the mount
285 * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
286 * XFS_IOC_FSGROWFSRT
287 */
288 int
289 xfs_growfs_data(
290 struct xfs_mount *mp,
291 struct xfs_growfs_data *in)
292 {
293 int error = 0;
294
295 if (!capable(CAP_SYS_ADMIN))
296 return -EPERM;
297 if (!mutex_trylock(&mp->m_growlock))
298 return -EWOULDBLOCK;
299
300 /* update imaxpct separately to the physical grow of the filesystem */
301 if (in->imaxpct != mp->m_sb.sb_imax_pct) {
302 error = xfs_growfs_imaxpct(mp, in->imaxpct);
303 if (error)
304 goto out_error;
305 }
306
307 if (in->newblocks != mp->m_sb.sb_dblocks) {
308 error = xfs_growfs_data_private(mp, in);
309 if (error)
310 goto out_error;
311 }
312
313 /* Post growfs calculations needed to reflect new state in operations */
314 if (mp->m_sb.sb_imax_pct) {
315 uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
316 do_div(icount, 100);
317 M_IGEO(mp)->maxicount = XFS_FSB_TO_INO(mp, icount);
318 } else
319 M_IGEO(mp)->maxicount = 0;
320
321 /* Update secondary superblocks now the physical grow has completed */
322 error = xfs_update_secondary_sbs(mp);
323
324 out_error:
325 /*
326 * Increment the generation unconditionally, the error could be from
327 * updating the secondary superblocks, in which case the new size
328 * is live already.
329 */
330 mp->m_generation++;
331 mutex_unlock(&mp->m_growlock);
332 return error;
333 }
334
335 int
336 xfs_growfs_log(
337 xfs_mount_t *mp,
338 struct xfs_growfs_log *in)
339 {
340 int error;
341
342 if (!capable(CAP_SYS_ADMIN))
343 return -EPERM;
344 if (!mutex_trylock(&mp->m_growlock))
345 return -EWOULDBLOCK;
346 error = xfs_growfs_log_private(mp, in);
347 mutex_unlock(&mp->m_growlock);
348 return error;
349 }
350
351 /*
352 * Reserve the requested number of blocks if available. Otherwise return
353 * as many as possible to satisfy the request. The actual number
354 * reserved are returned in outval.
355 */
356 int
357 xfs_reserve_blocks(
358 struct xfs_mount *mp,
359 uint64_t request)
360 {
361 int64_t lcounter, delta;
362 int64_t fdblks_delta = 0;
363 int64_t free;
364 int error = 0;
365
366 /*
367 * With per-cpu counters, this becomes an interesting problem. we need
368 * to work out if we are freeing or allocation blocks first, then we can
369 * do the modification as necessary.
370 *
371 * We do this under the m_sb_lock so that if we are near ENOSPC, we will
372 * hold out any changes while we work out what to do. This means that
373 * the amount of free space can change while we do this, so we need to
374 * retry if we end up trying to reserve more space than is available.
375 */
376 spin_lock(&mp->m_sb_lock);
377
378 /*
379 * If our previous reservation was larger than the current value,
380 * then move any unused blocks back to the free pool. Modify the resblks
381 * counters directly since we shouldn't have any problems unreserving
382 * space.
383 */
384 if (mp->m_resblks > request) {
385 lcounter = mp->m_resblks_avail - request;
386 if (lcounter > 0) { /* release unused blocks */
387 fdblks_delta = lcounter;
388 mp->m_resblks_avail -= lcounter;
389 }
390 mp->m_resblks = request;
391 if (fdblks_delta) {
392 spin_unlock(&mp->m_sb_lock);
393 xfs_add_fdblocks(mp, fdblks_delta);
394 spin_lock(&mp->m_sb_lock);
395 }
396
397 goto out;
398 }
399
400 /*
401 * If the request is larger than the current reservation, reserve the
402 * blocks before we update the reserve counters. Sample m_fdblocks and
403 * perform a partial reservation if the request exceeds free space.
404 *
405 * The code below estimates how many blocks it can request from
406 * fdblocks to stash in the reserve pool. This is a classic TOCTOU
407 * race since fdblocks updates are not always coordinated via
408 * m_sb_lock. Set the reserve size even if there's not enough free
409 * space to fill it because mod_fdblocks will refill an undersized
410 * reserve when it can.
411 */
412 free = percpu_counter_sum(&mp->m_fdblocks) -
413 xfs_fdblocks_unavailable(mp);
414 delta = request - mp->m_resblks;
415 mp->m_resblks = request;
416 if (delta > 0 && free > 0) {
417 /*
418 * We'll either succeed in getting space from the free block
419 * count or we'll get an ENOSPC. Don't set the reserved flag
420 * here - we don't want to reserve the extra reserve blocks
421 * from the reserve.
422 *
423 * The desired reserve size can change after we drop the lock.
424 * Use mod_fdblocks to put the space into the reserve or into
425 * fdblocks as appropriate.
426 */
427 fdblks_delta = min(free, delta);
428 spin_unlock(&mp->m_sb_lock);
429 error = xfs_dec_fdblocks(mp, fdblks_delta, 0);
430 if (!error)
431 xfs_add_fdblocks(mp, fdblks_delta);
432 spin_lock(&mp->m_sb_lock);
433 }
434 out:
435 spin_unlock(&mp->m_sb_lock);
436 return error;
437 }
438
439 int
440 xfs_fs_goingdown(
441 xfs_mount_t *mp,
442 uint32_t inflags)
443 {
444 switch (inflags) {
445 case XFS_FSOP_GOING_FLAGS_DEFAULT: {
446 if (!bdev_freeze(mp->m_super->s_bdev)) {
447 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
448 bdev_thaw(mp->m_super->s_bdev);
449 }
450 break;
451 }
452 case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
453 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
454 break;
455 case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
456 xfs_force_shutdown(mp,
457 SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
458 break;
459 default:
460 return -EINVAL;
461 }
462
463 return 0;
464 }
465
466 /*
467 * Force a shutdown of the filesystem instantly while keeping the filesystem
468 * consistent. We don't do an unmount here; just shutdown the shop, make sure
469 * that absolutely nothing persistent happens to this filesystem after this
470 * point.
471 *
472 * The shutdown state change is atomic, resulting in the first and only the
473 * first shutdown call processing the shutdown. This means we only shutdown the
474 * log once as it requires, and we don't spam the logs when multiple concurrent
475 * shutdowns race to set the shutdown flags.
476 */
477 void
478 xfs_do_force_shutdown(
479 struct xfs_mount *mp,
480 uint32_t flags,
481 char *fname,
482 int lnnum)
483 {
484 int tag;
485 const char *why;
486
487
488 if (test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &mp->m_opstate)) {
489 xlog_shutdown_wait(mp->m_log);
490 return;
491 }
492 if (mp->m_sb_bp)
493 mp->m_sb_bp->b_flags |= XBF_DONE;
494
495 if (flags & SHUTDOWN_FORCE_UMOUNT)
496 xfs_alert(mp, "User initiated shutdown received.");
497
498 if (xlog_force_shutdown(mp->m_log, flags)) {
499 tag = XFS_PTAG_SHUTDOWN_LOGERROR;
500 why = "Log I/O Error";
501 } else if (flags & SHUTDOWN_CORRUPT_INCORE) {
502 tag = XFS_PTAG_SHUTDOWN_CORRUPT;
503 why = "Corruption of in-memory data";
504 } else if (flags & SHUTDOWN_CORRUPT_ONDISK) {
505 tag = XFS_PTAG_SHUTDOWN_CORRUPT;
506 why = "Corruption of on-disk metadata";
507 } else if (flags & SHUTDOWN_DEVICE_REMOVED) {
508 tag = XFS_PTAG_SHUTDOWN_IOERROR;
509 why = "Block device removal";
510 } else {
511 tag = XFS_PTAG_SHUTDOWN_IOERROR;
512 why = "Metadata I/O Error";
513 }
514
515 trace_xfs_force_shutdown(mp, tag, flags, fname, lnnum);
516
517 xfs_alert_tag(mp, tag,
518 "%s (0x%x) detected at %pS (%s:%d). Shutting down filesystem.",
519 why, flags, __return_address, fname, lnnum);
520 xfs_alert(mp,
521 "Please unmount the filesystem and rectify the problem(s)");
522 if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
523 xfs_stack_trace();
524 }
525
526 /*
527 * Reserve free space for per-AG metadata.
528 */
529 int
530 xfs_fs_reserve_ag_blocks(
531 struct xfs_mount *mp)
532 {
533 xfs_agnumber_t agno;
534 struct xfs_perag *pag;
535 int error = 0;
536 int err2;
537
538 mp->m_finobt_nores = false;
539 for_each_perag(mp, agno, pag) {
540 err2 = xfs_ag_resv_init(pag, NULL);
541 if (err2 && !error)
542 error = err2;
543 }
544
545 if (error && error != -ENOSPC) {
546 xfs_warn(mp,
547 "Error %d reserving per-AG metadata reserve pool.", error);
548 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
549 }
550
551 return error;
552 }
553
554 /*
555 * Free space reserved for per-AG metadata.
556 */
557 void
558 xfs_fs_unreserve_ag_blocks(
559 struct xfs_mount *mp)
560 {
561 xfs_agnumber_t agno;
562 struct xfs_perag *pag;
563
564 for_each_perag(mp, agno, pag)
565 xfs_ag_resv_free(pag);
566 }
567
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