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