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 /* 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, resp: &M_RES(mp)->tr_growdata, blocks: -delta, rtextents: 0,
158 flags: 0, tpp: &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 error = xfs_ag_resv_free(pag);
217 xfs_perag_put(pag);
218 if (error)
219 return error;
220 }
221 /*
222 * Reserve AG metadata blocks. ENOSPC here does not mean there
223 * was a growfs failure, just that there still isn't space for
224 * new user data after the grow has been run.
225 */
226 error = xfs_fs_reserve_ag_blocks(mp);
227 if (error == -ENOSPC)
228 error = 0;
229 }
230 return error;
231
232out_trans_cancel:
233 xfs_trans_cancel(tp);
234out_free_unused_perag:
235 if (nagcount > oagcount)
236 xfs_free_unused_perag_range(mp, oagcount, nagcount);
237 return error;
238}
239
240static int
241xfs_growfs_log_private(
242 struct xfs_mount *mp, /* mount point for filesystem */
243 struct xfs_growfs_log *in) /* growfs log input struct */
244{
245 xfs_extlen_t nb;
246
247 nb = in->newblocks;
248 if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
249 return -EINVAL;
250 if (nb == mp->m_sb.sb_logblocks &&
251 in->isint == (mp->m_sb.sb_logstart != 0))
252 return -EINVAL;
253 /*
254 * Moving the log is hard, need new interfaces to sync
255 * the log first, hold off all activity while moving it.
256 * Can have shorter or longer log in the same space,
257 * or transform internal to external log or vice versa.
258 */
259 return -ENOSYS;
260}
261
262static int
263xfs_growfs_imaxpct(
264 struct xfs_mount *mp,
265 __u32 imaxpct)
266{
267 struct xfs_trans *tp;
268 int dpct;
269 int error;
270
271 if (imaxpct > 100)
272 return -EINVAL;
273
274 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
275 XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
276 if (error)
277 return error;
278
279 dpct = imaxpct - mp->m_sb.sb_imax_pct;
280 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
281 xfs_trans_set_sync(tp);
282 return xfs_trans_commit(tp);
283}
284
285/*
286 * protected versions of growfs function acquire and release locks on the mount
287 * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
288 * XFS_IOC_FSGROWFSRT
289 */
290int
291xfs_growfs_data(
292 struct xfs_mount *mp,
293 struct xfs_growfs_data *in)
294{
295 int error = 0;
296
297 if (!capable(CAP_SYS_ADMIN))
298 return -EPERM;
299 if (!mutex_trylock(lock: &mp->m_growlock))
300 return -EWOULDBLOCK;
301
302 /* update imaxpct separately to the physical grow of the filesystem */
303 if (in->imaxpct != mp->m_sb.sb_imax_pct) {
304 error = xfs_growfs_imaxpct(mp, imaxpct: in->imaxpct);
305 if (error)
306 goto out_error;
307 }
308
309 if (in->newblocks != mp->m_sb.sb_dblocks) {
310 error = xfs_growfs_data_private(mp, in);
311 if (error)
312 goto out_error;
313 }
314
315 /* Post growfs calculations needed to reflect new state in operations */
316 if (mp->m_sb.sb_imax_pct) {
317 uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
318 do_div(icount, 100);
319 M_IGEO(mp)->maxicount = XFS_FSB_TO_INO(mp, icount);
320 } else
321 M_IGEO(mp)->maxicount = 0;
322
323 /* Update secondary superblocks now the physical grow has completed */
324 error = xfs_update_secondary_sbs(mp);
325
326out_error:
327 /*
328 * Increment the generation unconditionally, the error could be from
329 * updating the secondary superblocks, in which case the new size
330 * is live already.
331 */
332 mp->m_generation++;
333 mutex_unlock(lock: &mp->m_growlock);
334 return error;
335}
336
337int
338xfs_growfs_log(
339 xfs_mount_t *mp,
340 struct xfs_growfs_log *in)
341{
342 int error;
343
344 if (!capable(CAP_SYS_ADMIN))
345 return -EPERM;
346 if (!mutex_trylock(lock: &mp->m_growlock))
347 return -EWOULDBLOCK;
348 error = xfs_growfs_log_private(mp, in);
349 mutex_unlock(lock: &mp->m_growlock);
350 return error;
351}
352
353/*
354 * Reserve the requested number of blocks if available. Otherwise return
355 * as many as possible to satisfy the request. The actual number
356 * reserved are returned in outval.
357 */
358int
359xfs_reserve_blocks(
360 struct xfs_mount *mp,
361 uint64_t request)
362{
363 int64_t lcounter, delta;
364 int64_t fdblks_delta = 0;
365 int64_t free;
366 int error = 0;
367
368 /*
369 * With per-cpu counters, this becomes an interesting problem. we need
370 * to work out if we are freeing or allocation blocks first, then we can
371 * do the modification as necessary.
372 *
373 * We do this under the m_sb_lock so that if we are near ENOSPC, we will
374 * hold out any changes while we work out what to do. This means that
375 * the amount of free space can change while we do this, so we need to
376 * retry if we end up trying to reserve more space than is available.
377 */
378 spin_lock(lock: &mp->m_sb_lock);
379
380 /*
381 * If our previous reservation was larger than the current value,
382 * then move any unused blocks back to the free pool. Modify the resblks
383 * counters directly since we shouldn't have any problems unreserving
384 * space.
385 */
386 if (mp->m_resblks > request) {
387 lcounter = mp->m_resblks_avail - request;
388 if (lcounter > 0) { /* release unused blocks */
389 fdblks_delta = lcounter;
390 mp->m_resblks_avail -= lcounter;
391 }
392 mp->m_resblks = request;
393 if (fdblks_delta) {
394 spin_unlock(lock: &mp->m_sb_lock);
395 error = xfs_mod_fdblocks(mp, delta: fdblks_delta, reserved: 0);
396 spin_lock(lock: &mp->m_sb_lock);
397 }
398
399 goto out;
400 }
401
402 /*
403 * If the request is larger than the current reservation, reserve the
404 * blocks before we update the reserve counters. Sample m_fdblocks and
405 * perform a partial reservation if the request exceeds free space.
406 *
407 * The code below estimates how many blocks it can request from
408 * fdblocks to stash in the reserve pool. This is a classic TOCTOU
409 * race since fdblocks updates are not always coordinated via
410 * m_sb_lock. Set the reserve size even if there's not enough free
411 * space to fill it because mod_fdblocks will refill an undersized
412 * reserve when it can.
413 */
414 free = percpu_counter_sum(fbc: &mp->m_fdblocks) -
415 xfs_fdblocks_unavailable(mp);
416 delta = request - mp->m_resblks;
417 mp->m_resblks = request;
418 if (delta > 0 && free > 0) {
419 /*
420 * We'll either succeed in getting space from the free block
421 * count or we'll get an ENOSPC. Don't set the reserved flag
422 * here - we don't want to reserve the extra reserve blocks
423 * from the reserve.
424 *
425 * The desired reserve size can change after we drop the lock.
426 * Use mod_fdblocks to put the space into the reserve or into
427 * fdblocks as appropriate.
428 */
429 fdblks_delta = min(free, delta);
430 spin_unlock(lock: &mp->m_sb_lock);
431 error = xfs_mod_fdblocks(mp, delta: -fdblks_delta, reserved: 0);
432 if (!error)
433 xfs_mod_fdblocks(mp, delta: fdblks_delta, reserved: 0);
434 spin_lock(lock: &mp->m_sb_lock);
435 }
436out:
437 spin_unlock(lock: &mp->m_sb_lock);
438 return error;
439}
440
441int
442xfs_fs_goingdown(
443 xfs_mount_t *mp,
444 uint32_t inflags)
445{
446 switch (inflags) {
447 case XFS_FSOP_GOING_FLAGS_DEFAULT: {
448 if (!bdev_freeze(bdev: mp->m_super->s_bdev)) {
449 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
450 bdev_thaw(bdev: mp->m_super->s_bdev);
451 }
452 break;
453 }
454 case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
455 xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
456 break;
457 case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
458 xfs_force_shutdown(mp,
459 SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
460 break;
461 default:
462 return -EINVAL;
463 }
464
465 return 0;
466}
467
468/*
469 * Force a shutdown of the filesystem instantly while keeping the filesystem
470 * consistent. We don't do an unmount here; just shutdown the shop, make sure
471 * that absolutely nothing persistent happens to this filesystem after this
472 * point.
473 *
474 * The shutdown state change is atomic, resulting in the first and only the
475 * first shutdown call processing the shutdown. This means we only shutdown the
476 * log once as it requires, and we don't spam the logs when multiple concurrent
477 * shutdowns race to set the shutdown flags.
478 */
479void
480xfs_do_force_shutdown(
481 struct xfs_mount *mp,
482 uint32_t flags,
483 char *fname,
484 int lnnum)
485{
486 int tag;
487 const char *why;
488
489
490 if (test_and_set_bit(XFS_OPSTATE_SHUTDOWN, addr: &mp->m_opstate)) {
491 xlog_shutdown_wait(log: mp->m_log);
492 return;
493 }
494 if (mp->m_sb_bp)
495 mp->m_sb_bp->b_flags |= XBF_DONE;
496
497 if (flags & SHUTDOWN_FORCE_UMOUNT)
498 xfs_alert(mp, "User initiated shutdown received.");
499
500 if (xlog_force_shutdown(log: mp->m_log, shutdown_flags: flags)) {
501 tag = XFS_PTAG_SHUTDOWN_LOGERROR;
502 why = "Log I/O Error";
503 } else if (flags & SHUTDOWN_CORRUPT_INCORE) {
504 tag = XFS_PTAG_SHUTDOWN_CORRUPT;
505 why = "Corruption of in-memory data";
506 } else if (flags & SHUTDOWN_CORRUPT_ONDISK) {
507 tag = XFS_PTAG_SHUTDOWN_CORRUPT;
508 why = "Corruption of on-disk metadata";
509 } else if (flags & SHUTDOWN_DEVICE_REMOVED) {
510 tag = XFS_PTAG_SHUTDOWN_IOERROR;
511 why = "Block device removal";
512 } else {
513 tag = XFS_PTAG_SHUTDOWN_IOERROR;
514 why = "Metadata I/O Error";
515 }
516
517 trace_xfs_force_shutdown(mp, ptag: tag, flags, fname, line_num: lnnum);
518
519 xfs_alert_tag(mp, tag,
520"%s (0x%x) detected at %pS (%s:%d). Shutting down filesystem.",
521 why, flags, __return_address, fname, lnnum);
522 xfs_alert(mp,
523 "Please unmount the filesystem and rectify the problem(s)");
524 if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
525 xfs_stack_trace();
526}
527
528/*
529 * Reserve free space for per-AG metadata.
530 */
531int
532xfs_fs_reserve_ag_blocks(
533 struct xfs_mount *mp)
534{
535 xfs_agnumber_t agno;
536 struct xfs_perag *pag;
537 int error = 0;
538 int err2;
539
540 mp->m_finobt_nores = false;
541 for_each_perag(mp, agno, pag) {
542 err2 = xfs_ag_resv_init(pag, NULL);
543 if (err2 && !error)
544 error = err2;
545 }
546
547 if (error && error != -ENOSPC) {
548 xfs_warn(mp,
549 "Error %d reserving per-AG metadata reserve pool.", error);
550 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
551 }
552
553 return error;
554}
555
556/*
557 * Free space reserved for per-AG metadata.
558 */
559int
560xfs_fs_unreserve_ag_blocks(
561 struct xfs_mount *mp)
562{
563 xfs_agnumber_t agno;
564 struct xfs_perag *pag;
565 int error = 0;
566 int err2;
567
568 for_each_perag(mp, agno, pag) {
569 err2 = xfs_ag_resv_free(pag);
570 if (err2 && !error)
571 error = err2;
572 }
573
574 if (error)
575 xfs_warn(mp,
576 "Error %d freeing per-AG metadata reserve pool.", error);
577
578 return error;
579}
580

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