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