xref: /openbmc/linux/fs/xfs/xfs_fsops.c (revision 95298d63)
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_ag.h"
21 #include "xfs_ag_resv.h"
22 
23 /*
24  * growfs operations
25  */
26 static int
27 xfs_growfs_data_private(
28 	xfs_mount_t		*mp,		/* mount point for filesystem */
29 	xfs_growfs_data_t	*in)		/* growfs data input struct */
30 {
31 	xfs_buf_t		*bp;
32 	int			error;
33 	xfs_agnumber_t		nagcount;
34 	xfs_agnumber_t		nagimax = 0;
35 	xfs_rfsblock_t		nb, nb_mod;
36 	xfs_rfsblock_t		new;
37 	xfs_agnumber_t		oagcount;
38 	xfs_trans_t		*tp;
39 	struct aghdr_init_data	id = {};
40 
41 	nb = in->newblocks;
42 	if (nb < mp->m_sb.sb_dblocks)
43 		return -EINVAL;
44 	if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
45 		return error;
46 	error = xfs_buf_read_uncached(mp->m_ddev_targp,
47 				XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
48 				XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
49 	if (error)
50 		return error;
51 	xfs_buf_relse(bp);
52 
53 	new = nb;	/* use new as a temporary here */
54 	nb_mod = do_div(new, mp->m_sb.sb_agblocks);
55 	nagcount = new + (nb_mod != 0);
56 	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
57 		nagcount--;
58 		nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
59 		if (nb < mp->m_sb.sb_dblocks)
60 			return -EINVAL;
61 	}
62 	new = nb - mp->m_sb.sb_dblocks;
63 	oagcount = mp->m_sb.sb_agcount;
64 
65 	/* allocate the new per-ag structures */
66 	if (nagcount > oagcount) {
67 		error = xfs_initialize_perag(mp, nagcount, &nagimax);
68 		if (error)
69 			return error;
70 	}
71 
72 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
73 			XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
74 	if (error)
75 		return error;
76 
77 	/*
78 	 * Write new AG headers to disk. Non-transactional, but need to be
79 	 * written and completed prior to the growfs transaction being logged.
80 	 * To do this, we use a delayed write buffer list and wait for
81 	 * submission and IO completion of the list as a whole. This allows the
82 	 * IO subsystem to merge all the AG headers in a single AG into a single
83 	 * IO and hide most of the latency of the IO from us.
84 	 *
85 	 * This also means that if we get an error whilst building the buffer
86 	 * list to write, we can cancel the entire list without having written
87 	 * anything.
88 	 */
89 	INIT_LIST_HEAD(&id.buffer_list);
90 	for (id.agno = nagcount - 1;
91 	     id.agno >= oagcount;
92 	     id.agno--, new -= id.agsize) {
93 
94 		if (id.agno == nagcount - 1)
95 			id.agsize = nb -
96 				(id.agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
97 		else
98 			id.agsize = mp->m_sb.sb_agblocks;
99 
100 		error = xfs_ag_init_headers(mp, &id);
101 		if (error) {
102 			xfs_buf_delwri_cancel(&id.buffer_list);
103 			goto out_trans_cancel;
104 		}
105 	}
106 	error = xfs_buf_delwri_submit(&id.buffer_list);
107 	if (error)
108 		goto out_trans_cancel;
109 
110 	xfs_trans_agblocks_delta(tp, id.nfree);
111 
112 	/* If there are new blocks in the old last AG, extend it. */
113 	if (new) {
114 		error = xfs_ag_extend_space(mp, tp, &id, new);
115 		if (error)
116 			goto out_trans_cancel;
117 	}
118 
119 	/*
120 	 * Update changed superblock fields transactionally. These are not
121 	 * seen by the rest of the world until the transaction commit applies
122 	 * them atomically to the superblock.
123 	 */
124 	if (nagcount > oagcount)
125 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
126 	if (nb > mp->m_sb.sb_dblocks)
127 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
128 				 nb - mp->m_sb.sb_dblocks);
129 	if (id.nfree)
130 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
131 	xfs_trans_set_sync(tp);
132 	error = xfs_trans_commit(tp);
133 	if (error)
134 		return error;
135 
136 	/* New allocation groups fully initialized, so update mount struct */
137 	if (nagimax)
138 		mp->m_maxagi = nagimax;
139 	xfs_set_low_space_thresholds(mp);
140 	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
141 
142 	/*
143 	 * If we expanded the last AG, free the per-AG reservation
144 	 * so we can reinitialize it with the new size.
145 	 */
146 	if (new) {
147 		struct xfs_perag	*pag;
148 
149 		pag = xfs_perag_get(mp, id.agno);
150 		error = xfs_ag_resv_free(pag);
151 		xfs_perag_put(pag);
152 		if (error)
153 			return error;
154 	}
155 
156 	/*
157 	 * Reserve AG metadata blocks. ENOSPC here does not mean there was a
158 	 * growfs failure, just that there still isn't space for new user data
159 	 * after the grow has been run.
160 	 */
161 	error = xfs_fs_reserve_ag_blocks(mp);
162 	if (error == -ENOSPC)
163 		error = 0;
164 	return error;
165 
166 out_trans_cancel:
167 	xfs_trans_cancel(tp);
168 	return error;
169 }
170 
171 static int
172 xfs_growfs_log_private(
173 	xfs_mount_t		*mp,	/* mount point for filesystem */
174 	xfs_growfs_log_t	*in)	/* growfs log input struct */
175 {
176 	xfs_extlen_t		nb;
177 
178 	nb = in->newblocks;
179 	if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
180 		return -EINVAL;
181 	if (nb == mp->m_sb.sb_logblocks &&
182 	    in->isint == (mp->m_sb.sb_logstart != 0))
183 		return -EINVAL;
184 	/*
185 	 * Moving the log is hard, need new interfaces to sync
186 	 * the log first, hold off all activity while moving it.
187 	 * Can have shorter or longer log in the same space,
188 	 * or transform internal to external log or vice versa.
189 	 */
190 	return -ENOSYS;
191 }
192 
193 static int
194 xfs_growfs_imaxpct(
195 	struct xfs_mount	*mp,
196 	__u32			imaxpct)
197 {
198 	struct xfs_trans	*tp;
199 	int			dpct;
200 	int			error;
201 
202 	if (imaxpct > 100)
203 		return -EINVAL;
204 
205 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
206 			XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
207 	if (error)
208 		return error;
209 
210 	dpct = imaxpct - mp->m_sb.sb_imax_pct;
211 	xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
212 	xfs_trans_set_sync(tp);
213 	return xfs_trans_commit(tp);
214 }
215 
216 /*
217  * protected versions of growfs function acquire and release locks on the mount
218  * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
219  * XFS_IOC_FSGROWFSRT
220  */
221 int
222 xfs_growfs_data(
223 	struct xfs_mount	*mp,
224 	struct xfs_growfs_data	*in)
225 {
226 	int			error = 0;
227 
228 	if (!capable(CAP_SYS_ADMIN))
229 		return -EPERM;
230 	if (!mutex_trylock(&mp->m_growlock))
231 		return -EWOULDBLOCK;
232 
233 	/* update imaxpct separately to the physical grow of the filesystem */
234 	if (in->imaxpct != mp->m_sb.sb_imax_pct) {
235 		error = xfs_growfs_imaxpct(mp, in->imaxpct);
236 		if (error)
237 			goto out_error;
238 	}
239 
240 	if (in->newblocks != mp->m_sb.sb_dblocks) {
241 		error = xfs_growfs_data_private(mp, in);
242 		if (error)
243 			goto out_error;
244 	}
245 
246 	/* Post growfs calculations needed to reflect new state in operations */
247 	if (mp->m_sb.sb_imax_pct) {
248 		uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
249 		do_div(icount, 100);
250 		M_IGEO(mp)->maxicount = XFS_FSB_TO_INO(mp, icount);
251 	} else
252 		M_IGEO(mp)->maxicount = 0;
253 
254 	/* Update secondary superblocks now the physical grow has completed */
255 	error = xfs_update_secondary_sbs(mp);
256 
257 out_error:
258 	/*
259 	 * Increment the generation unconditionally, the error could be from
260 	 * updating the secondary superblocks, in which case the new size
261 	 * is live already.
262 	 */
263 	mp->m_generation++;
264 	mutex_unlock(&mp->m_growlock);
265 	return error;
266 }
267 
268 int
269 xfs_growfs_log(
270 	xfs_mount_t		*mp,
271 	xfs_growfs_log_t	*in)
272 {
273 	int error;
274 
275 	if (!capable(CAP_SYS_ADMIN))
276 		return -EPERM;
277 	if (!mutex_trylock(&mp->m_growlock))
278 		return -EWOULDBLOCK;
279 	error = xfs_growfs_log_private(mp, in);
280 	mutex_unlock(&mp->m_growlock);
281 	return error;
282 }
283 
284 /*
285  * exported through ioctl XFS_IOC_FSCOUNTS
286  */
287 
288 void
289 xfs_fs_counts(
290 	xfs_mount_t		*mp,
291 	xfs_fsop_counts_t	*cnt)
292 {
293 	cnt->allocino = percpu_counter_read_positive(&mp->m_icount);
294 	cnt->freeino = percpu_counter_read_positive(&mp->m_ifree);
295 	cnt->freedata = percpu_counter_read_positive(&mp->m_fdblocks) -
296 						mp->m_alloc_set_aside;
297 
298 	spin_lock(&mp->m_sb_lock);
299 	cnt->freertx = mp->m_sb.sb_frextents;
300 	spin_unlock(&mp->m_sb_lock);
301 }
302 
303 /*
304  * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
305  *
306  * xfs_reserve_blocks is called to set m_resblks
307  * in the in-core mount table. The number of unused reserved blocks
308  * is kept in m_resblks_avail.
309  *
310  * Reserve the requested number of blocks if available. Otherwise return
311  * as many as possible to satisfy the request. The actual number
312  * reserved are returned in outval
313  *
314  * A null inval pointer indicates that only the current reserved blocks
315  * available  should  be returned no settings are changed.
316  */
317 
318 int
319 xfs_reserve_blocks(
320 	xfs_mount_t             *mp,
321 	uint64_t              *inval,
322 	xfs_fsop_resblks_t      *outval)
323 {
324 	int64_t			lcounter, delta;
325 	int64_t			fdblks_delta = 0;
326 	uint64_t		request;
327 	int64_t			free;
328 	int			error = 0;
329 
330 	/* If inval is null, report current values and return */
331 	if (inval == (uint64_t *)NULL) {
332 		if (!outval)
333 			return -EINVAL;
334 		outval->resblks = mp->m_resblks;
335 		outval->resblks_avail = mp->m_resblks_avail;
336 		return 0;
337 	}
338 
339 	request = *inval;
340 
341 	/*
342 	 * With per-cpu counters, this becomes an interesting problem. we need
343 	 * to work out if we are freeing or allocation blocks first, then we can
344 	 * do the modification as necessary.
345 	 *
346 	 * We do this under the m_sb_lock so that if we are near ENOSPC, we will
347 	 * hold out any changes while we work out what to do. This means that
348 	 * the amount of free space can change while we do this, so we need to
349 	 * retry if we end up trying to reserve more space than is available.
350 	 */
351 	spin_lock(&mp->m_sb_lock);
352 
353 	/*
354 	 * If our previous reservation was larger than the current value,
355 	 * then move any unused blocks back to the free pool. Modify the resblks
356 	 * counters directly since we shouldn't have any problems unreserving
357 	 * space.
358 	 */
359 	if (mp->m_resblks > request) {
360 		lcounter = mp->m_resblks_avail - request;
361 		if (lcounter  > 0) {		/* release unused blocks */
362 			fdblks_delta = lcounter;
363 			mp->m_resblks_avail -= lcounter;
364 		}
365 		mp->m_resblks = request;
366 		if (fdblks_delta) {
367 			spin_unlock(&mp->m_sb_lock);
368 			error = xfs_mod_fdblocks(mp, fdblks_delta, 0);
369 			spin_lock(&mp->m_sb_lock);
370 		}
371 
372 		goto out;
373 	}
374 
375 	/*
376 	 * If the request is larger than the current reservation, reserve the
377 	 * blocks before we update the reserve counters. Sample m_fdblocks and
378 	 * perform a partial reservation if the request exceeds free space.
379 	 */
380 	error = -ENOSPC;
381 	do {
382 		free = percpu_counter_sum(&mp->m_fdblocks) -
383 						mp->m_alloc_set_aside;
384 		if (free <= 0)
385 			break;
386 
387 		delta = request - mp->m_resblks;
388 		lcounter = free - delta;
389 		if (lcounter < 0)
390 			/* We can't satisfy the request, just get what we can */
391 			fdblks_delta = free;
392 		else
393 			fdblks_delta = delta;
394 
395 		/*
396 		 * We'll either succeed in getting space from the free block
397 		 * count or we'll get an ENOSPC. If we get a ENOSPC, it means
398 		 * things changed while we were calculating fdblks_delta and so
399 		 * we should try again to see if there is anything left to
400 		 * reserve.
401 		 *
402 		 * Don't set the reserved flag here - we don't want to reserve
403 		 * the extra reserve blocks from the reserve.....
404 		 */
405 		spin_unlock(&mp->m_sb_lock);
406 		error = xfs_mod_fdblocks(mp, -fdblks_delta, 0);
407 		spin_lock(&mp->m_sb_lock);
408 	} while (error == -ENOSPC);
409 
410 	/*
411 	 * Update the reserve counters if blocks have been successfully
412 	 * allocated.
413 	 */
414 	if (!error && fdblks_delta) {
415 		mp->m_resblks += fdblks_delta;
416 		mp->m_resblks_avail += fdblks_delta;
417 	}
418 
419 out:
420 	if (outval) {
421 		outval->resblks = mp->m_resblks;
422 		outval->resblks_avail = mp->m_resblks_avail;
423 	}
424 
425 	spin_unlock(&mp->m_sb_lock);
426 	return error;
427 }
428 
429 int
430 xfs_fs_goingdown(
431 	xfs_mount_t	*mp,
432 	uint32_t	inflags)
433 {
434 	switch (inflags) {
435 	case XFS_FSOP_GOING_FLAGS_DEFAULT: {
436 		struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);
437 
438 		if (sb && !IS_ERR(sb)) {
439 			xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
440 			thaw_bdev(sb->s_bdev, sb);
441 		}
442 
443 		break;
444 	}
445 	case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
446 		xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
447 		break;
448 	case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
449 		xfs_force_shutdown(mp,
450 				SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
451 		break;
452 	default:
453 		return -EINVAL;
454 	}
455 
456 	return 0;
457 }
458 
459 /*
460  * Force a shutdown of the filesystem instantly while keeping the filesystem
461  * consistent. We don't do an unmount here; just shutdown the shop, make sure
462  * that absolutely nothing persistent happens to this filesystem after this
463  * point.
464  */
465 void
466 xfs_do_force_shutdown(
467 	struct xfs_mount *mp,
468 	int		flags,
469 	char		*fname,
470 	int		lnnum)
471 {
472 	bool		logerror = flags & SHUTDOWN_LOG_IO_ERROR;
473 
474 	/*
475 	 * No need to duplicate efforts.
476 	 */
477 	if (XFS_FORCED_SHUTDOWN(mp) && !logerror)
478 		return;
479 
480 	/*
481 	 * This flags XFS_MOUNT_FS_SHUTDOWN, makes sure that we don't
482 	 * queue up anybody new on the log reservations, and wakes up
483 	 * everybody who's sleeping on log reservations to tell them
484 	 * the bad news.
485 	 */
486 	if (xfs_log_force_umount(mp, logerror))
487 		return;
488 
489 	if (flags & SHUTDOWN_FORCE_UMOUNT) {
490 		xfs_alert(mp,
491 "User initiated shutdown received. Shutting down filesystem");
492 		return;
493 	}
494 
495 	xfs_notice(mp,
496 "%s(0x%x) called from line %d of file %s. Return address = "PTR_FMT,
497 		__func__, flags, lnnum, fname, __return_address);
498 
499 	if (flags & SHUTDOWN_CORRUPT_INCORE) {
500 		xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
501 "Corruption of in-memory data detected.  Shutting down filesystem");
502 		if (XFS_ERRLEVEL_HIGH <= xfs_error_level)
503 			xfs_stack_trace();
504 	} else if (logerror) {
505 		xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_LOGERROR,
506 			"Log I/O Error Detected. Shutting down filesystem");
507 	} else {
508 		xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
509 			"I/O Error Detected. Shutting down filesystem");
510 	}
511 
512 	xfs_alert(mp,
513 		"Please unmount the filesystem and rectify the problem(s)");
514 }
515 
516 /*
517  * Reserve free space for per-AG metadata.
518  */
519 int
520 xfs_fs_reserve_ag_blocks(
521 	struct xfs_mount	*mp)
522 {
523 	xfs_agnumber_t		agno;
524 	struct xfs_perag	*pag;
525 	int			error = 0;
526 	int			err2;
527 
528 	mp->m_finobt_nores = false;
529 	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
530 		pag = xfs_perag_get(mp, agno);
531 		err2 = xfs_ag_resv_init(pag, NULL);
532 		xfs_perag_put(pag);
533 		if (err2 && !error)
534 			error = err2;
535 	}
536 
537 	if (error && error != -ENOSPC) {
538 		xfs_warn(mp,
539 	"Error %d reserving per-AG metadata reserve pool.", error);
540 		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
541 	}
542 
543 	return error;
544 }
545 
546 /*
547  * Free space reserved for per-AG metadata.
548  */
549 int
550 xfs_fs_unreserve_ag_blocks(
551 	struct xfs_mount	*mp)
552 {
553 	xfs_agnumber_t		agno;
554 	struct xfs_perag	*pag;
555 	int			error = 0;
556 	int			err2;
557 
558 	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
559 		pag = xfs_perag_get(mp, agno);
560 		err2 = xfs_ag_resv_free(pag);
561 		xfs_perag_put(pag);
562 		if (err2 && !error)
563 			error = err2;
564 	}
565 
566 	if (error)
567 		xfs_warn(mp,
568 	"Error %d freeing per-AG metadata reserve pool.", error);
569 
570 	return error;
571 }
572