xref: /openbmc/linux/fs/xfs/xfs_fsops.c (revision f9a82c48)
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_defer.h"
15 #include "xfs_trans.h"
16 #include "xfs_error.h"
17 #include "xfs_btree.h"
18 #include "xfs_alloc.h"
19 #include "xfs_fsops.h"
20 #include "xfs_trans_space.h"
21 #include "xfs_rtalloc.h"
22 #include "xfs_trace.h"
23 #include "xfs_log.h"
24 #include "xfs_ag.h"
25 #include "xfs_ag_resv.h"
26 
27 /*
28  * growfs operations
29  */
30 static int
31 xfs_growfs_data_private(
32 	xfs_mount_t		*mp,		/* mount point for filesystem */
33 	xfs_growfs_data_t	*in)		/* growfs data input struct */
34 {
35 	xfs_buf_t		*bp;
36 	int			error;
37 	xfs_agnumber_t		nagcount;
38 	xfs_agnumber_t		nagimax = 0;
39 	xfs_rfsblock_t		nb, nb_mod;
40 	xfs_rfsblock_t		new;
41 	xfs_agnumber_t		oagcount;
42 	xfs_trans_t		*tp;
43 	struct aghdr_init_data	id = {};
44 
45 	nb = in->newblocks;
46 	if (nb < mp->m_sb.sb_dblocks)
47 		return -EINVAL;
48 	if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
49 		return error;
50 	error = xfs_buf_read_uncached(mp->m_ddev_targp,
51 				XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
52 				XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
53 	if (error)
54 		return error;
55 	xfs_buf_relse(bp);
56 
57 	new = nb;	/* use new as a temporary here */
58 	nb_mod = do_div(new, mp->m_sb.sb_agblocks);
59 	nagcount = new + (nb_mod != 0);
60 	if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
61 		nagcount--;
62 		nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
63 		if (nb < mp->m_sb.sb_dblocks)
64 			return -EINVAL;
65 	}
66 	new = nb - mp->m_sb.sb_dblocks;
67 	oagcount = mp->m_sb.sb_agcount;
68 
69 	/* allocate the new per-ag structures */
70 	if (nagcount > oagcount) {
71 		error = xfs_initialize_perag(mp, nagcount, &nagimax);
72 		if (error)
73 			return error;
74 	}
75 
76 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
77 			XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
78 	if (error)
79 		return error;
80 
81 	/*
82 	 * Write new AG headers to disk. Non-transactional, but need to be
83 	 * written and completed prior to the growfs transaction being logged.
84 	 * To do this, we use a delayed write buffer list and wait for
85 	 * submission and IO completion of the list as a whole. This allows the
86 	 * IO subsystem to merge all the AG headers in a single AG into a single
87 	 * IO and hide most of the latency of the IO from us.
88 	 *
89 	 * This also means that if we get an error whilst building the buffer
90 	 * list to write, we can cancel the entire list without having written
91 	 * anything.
92 	 */
93 	INIT_LIST_HEAD(&id.buffer_list);
94 	for (id.agno = nagcount - 1;
95 	     id.agno >= oagcount;
96 	     id.agno--, new -= id.agsize) {
97 
98 		if (id.agno == nagcount - 1)
99 			id.agsize = nb -
100 				(id.agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
101 		else
102 			id.agsize = mp->m_sb.sb_agblocks;
103 
104 		error = xfs_ag_init_headers(mp, &id);
105 		if (error) {
106 			xfs_buf_delwri_cancel(&id.buffer_list);
107 			goto out_trans_cancel;
108 		}
109 	}
110 	error = xfs_buf_delwri_submit(&id.buffer_list);
111 	if (error)
112 		goto out_trans_cancel;
113 
114 	xfs_trans_agblocks_delta(tp, id.nfree);
115 
116 	/* If there are new blocks in the old last AG, extend it. */
117 	if (new) {
118 		error = xfs_ag_extend_space(mp, tp, &id, new);
119 		if (error)
120 			goto out_trans_cancel;
121 	}
122 
123 	/*
124 	 * Update changed superblock fields transactionally. These are not
125 	 * seen by the rest of the world until the transaction commit applies
126 	 * them atomically to the superblock.
127 	 */
128 	if (nagcount > oagcount)
129 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
130 	if (nb > mp->m_sb.sb_dblocks)
131 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
132 				 nb - mp->m_sb.sb_dblocks);
133 	if (id.nfree)
134 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree);
135 	xfs_trans_set_sync(tp);
136 	error = xfs_trans_commit(tp);
137 	if (error)
138 		return error;
139 
140 	/* New allocation groups fully initialized, so update mount struct */
141 	if (nagimax)
142 		mp->m_maxagi = nagimax;
143 	xfs_set_low_space_thresholds(mp);
144 	mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
145 
146 	/*
147 	 * If we expanded the last AG, free the per-AG reservation
148 	 * so we can reinitialize it with the new size.
149 	 */
150 	if (new) {
151 		struct xfs_perag	*pag;
152 
153 		pag = xfs_perag_get(mp, id.agno);
154 		error = xfs_ag_resv_free(pag);
155 		xfs_perag_put(pag);
156 		if (error)
157 			return error;
158 	}
159 
160 	/*
161 	 * Reserve AG metadata blocks. ENOSPC here does not mean there was a
162 	 * growfs failure, just that there still isn't space for new user data
163 	 * after the grow has been run.
164 	 */
165 	error = xfs_fs_reserve_ag_blocks(mp);
166 	if (error == -ENOSPC)
167 		error = 0;
168 	return error;
169 
170 out_trans_cancel:
171 	xfs_trans_cancel(tp);
172 	return error;
173 }
174 
175 static int
176 xfs_growfs_log_private(
177 	xfs_mount_t		*mp,	/* mount point for filesystem */
178 	xfs_growfs_log_t	*in)	/* growfs log input struct */
179 {
180 	xfs_extlen_t		nb;
181 
182 	nb = in->newblocks;
183 	if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
184 		return -EINVAL;
185 	if (nb == mp->m_sb.sb_logblocks &&
186 	    in->isint == (mp->m_sb.sb_logstart != 0))
187 		return -EINVAL;
188 	/*
189 	 * Moving the log is hard, need new interfaces to sync
190 	 * the log first, hold off all activity while moving it.
191 	 * Can have shorter or longer log in the same space,
192 	 * or transform internal to external log or vice versa.
193 	 */
194 	return -ENOSYS;
195 }
196 
197 static int
198 xfs_growfs_imaxpct(
199 	struct xfs_mount	*mp,
200 	__u32			imaxpct)
201 {
202 	struct xfs_trans	*tp;
203 	int			dpct;
204 	int			error;
205 
206 	if (imaxpct > 100)
207 		return -EINVAL;
208 
209 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
210 			XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
211 	if (error)
212 		return error;
213 
214 	dpct = imaxpct - mp->m_sb.sb_imax_pct;
215 	xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
216 	xfs_trans_set_sync(tp);
217 	return xfs_trans_commit(tp);
218 }
219 
220 /*
221  * protected versions of growfs function acquire and release locks on the mount
222  * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
223  * XFS_IOC_FSGROWFSRT
224  */
225 int
226 xfs_growfs_data(
227 	struct xfs_mount	*mp,
228 	struct xfs_growfs_data	*in)
229 {
230 	int			error = 0;
231 
232 	if (!capable(CAP_SYS_ADMIN))
233 		return -EPERM;
234 	if (!mutex_trylock(&mp->m_growlock))
235 		return -EWOULDBLOCK;
236 
237 	/* update imaxpct separately to the physical grow of the filesystem */
238 	if (in->imaxpct != mp->m_sb.sb_imax_pct) {
239 		error = xfs_growfs_imaxpct(mp, in->imaxpct);
240 		if (error)
241 			goto out_error;
242 	}
243 
244 	if (in->newblocks != mp->m_sb.sb_dblocks) {
245 		error = xfs_growfs_data_private(mp, in);
246 		if (error)
247 			goto out_error;
248 	}
249 
250 	/* Post growfs calculations needed to reflect new state in operations */
251 	if (mp->m_sb.sb_imax_pct) {
252 		uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
253 		do_div(icount, 100);
254 		mp->m_maxicount = XFS_FSB_TO_INO(mp, icount);
255 	} else
256 		mp->m_maxicount = 0;
257 
258 	/* Update secondary superblocks now the physical grow has completed */
259 	error = xfs_update_secondary_sbs(mp);
260 
261 out_error:
262 	/*
263 	 * Increment the generation unconditionally, the error could be from
264 	 * updating the secondary superblocks, in which case the new size
265 	 * is live already.
266 	 */
267 	mp->m_generation++;
268 	mutex_unlock(&mp->m_growlock);
269 	return error;
270 }
271 
272 int
273 xfs_growfs_log(
274 	xfs_mount_t		*mp,
275 	xfs_growfs_log_t	*in)
276 {
277 	int error;
278 
279 	if (!capable(CAP_SYS_ADMIN))
280 		return -EPERM;
281 	if (!mutex_trylock(&mp->m_growlock))
282 		return -EWOULDBLOCK;
283 	error = xfs_growfs_log_private(mp, in);
284 	mutex_unlock(&mp->m_growlock);
285 	return error;
286 }
287 
288 /*
289  * exported through ioctl XFS_IOC_FSCOUNTS
290  */
291 
292 int
293 xfs_fs_counts(
294 	xfs_mount_t		*mp,
295 	xfs_fsop_counts_t	*cnt)
296 {
297 	cnt->allocino = percpu_counter_read_positive(&mp->m_icount);
298 	cnt->freeino = percpu_counter_read_positive(&mp->m_ifree);
299 	cnt->freedata = percpu_counter_read_positive(&mp->m_fdblocks) -
300 						mp->m_alloc_set_aside;
301 
302 	spin_lock(&mp->m_sb_lock);
303 	cnt->freertx = mp->m_sb.sb_frextents;
304 	spin_unlock(&mp->m_sb_lock);
305 	return 0;
306 }
307 
308 /*
309  * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
310  *
311  * xfs_reserve_blocks is called to set m_resblks
312  * in the in-core mount table. The number of unused reserved blocks
313  * is kept in m_resblks_avail.
314  *
315  * Reserve the requested number of blocks if available. Otherwise return
316  * as many as possible to satisfy the request. The actual number
317  * reserved are returned in outval
318  *
319  * A null inval pointer indicates that only the current reserved blocks
320  * available  should  be returned no settings are changed.
321  */
322 
323 int
324 xfs_reserve_blocks(
325 	xfs_mount_t             *mp,
326 	uint64_t              *inval,
327 	xfs_fsop_resblks_t      *outval)
328 {
329 	int64_t			lcounter, delta;
330 	int64_t			fdblks_delta = 0;
331 	uint64_t		request;
332 	int64_t			free;
333 	int			error = 0;
334 
335 	/* If inval is null, report current values and return */
336 	if (inval == (uint64_t *)NULL) {
337 		if (!outval)
338 			return -EINVAL;
339 		outval->resblks = mp->m_resblks;
340 		outval->resblks_avail = mp->m_resblks_avail;
341 		return 0;
342 	}
343 
344 	request = *inval;
345 
346 	/*
347 	 * With per-cpu counters, this becomes an interesting problem. we need
348 	 * to work out if we are freeing or allocation blocks first, then we can
349 	 * do the modification as necessary.
350 	 *
351 	 * We do this under the m_sb_lock so that if we are near ENOSPC, we will
352 	 * hold out any changes while we work out what to do. This means that
353 	 * the amount of free space can change while we do this, so we need to
354 	 * retry if we end up trying to reserve more space than is available.
355 	 */
356 	spin_lock(&mp->m_sb_lock);
357 
358 	/*
359 	 * If our previous reservation was larger than the current value,
360 	 * then move any unused blocks back to the free pool. Modify the resblks
361 	 * counters directly since we shouldn't have any problems unreserving
362 	 * space.
363 	 */
364 	if (mp->m_resblks > request) {
365 		lcounter = mp->m_resblks_avail - request;
366 		if (lcounter  > 0) {		/* release unused blocks */
367 			fdblks_delta = lcounter;
368 			mp->m_resblks_avail -= lcounter;
369 		}
370 		mp->m_resblks = request;
371 		if (fdblks_delta) {
372 			spin_unlock(&mp->m_sb_lock);
373 			error = xfs_mod_fdblocks(mp, fdblks_delta, 0);
374 			spin_lock(&mp->m_sb_lock);
375 		}
376 
377 		goto out;
378 	}
379 
380 	/*
381 	 * If the request is larger than the current reservation, reserve the
382 	 * blocks before we update the reserve counters. Sample m_fdblocks and
383 	 * perform a partial reservation if the request exceeds free space.
384 	 */
385 	error = -ENOSPC;
386 	do {
387 		free = percpu_counter_sum(&mp->m_fdblocks) -
388 						mp->m_alloc_set_aside;
389 		if (free <= 0)
390 			break;
391 
392 		delta = request - mp->m_resblks;
393 		lcounter = free - delta;
394 		if (lcounter < 0)
395 			/* We can't satisfy the request, just get what we can */
396 			fdblks_delta = free;
397 		else
398 			fdblks_delta = delta;
399 
400 		/*
401 		 * We'll either succeed in getting space from the free block
402 		 * count or we'll get an ENOSPC. If we get a ENOSPC, it means
403 		 * things changed while we were calculating fdblks_delta and so
404 		 * we should try again to see if there is anything left to
405 		 * reserve.
406 		 *
407 		 * Don't set the reserved flag here - we don't want to reserve
408 		 * the extra reserve blocks from the reserve.....
409 		 */
410 		spin_unlock(&mp->m_sb_lock);
411 		error = xfs_mod_fdblocks(mp, -fdblks_delta, 0);
412 		spin_lock(&mp->m_sb_lock);
413 	} while (error == -ENOSPC);
414 
415 	/*
416 	 * Update the reserve counters if blocks have been successfully
417 	 * allocated.
418 	 */
419 	if (!error && fdblks_delta) {
420 		mp->m_resblks += fdblks_delta;
421 		mp->m_resblks_avail += fdblks_delta;
422 	}
423 
424 out:
425 	if (outval) {
426 		outval->resblks = mp->m_resblks;
427 		outval->resblks_avail = mp->m_resblks_avail;
428 	}
429 
430 	spin_unlock(&mp->m_sb_lock);
431 	return error;
432 }
433 
434 int
435 xfs_fs_goingdown(
436 	xfs_mount_t	*mp,
437 	uint32_t	inflags)
438 {
439 	switch (inflags) {
440 	case XFS_FSOP_GOING_FLAGS_DEFAULT: {
441 		struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);
442 
443 		if (sb && !IS_ERR(sb)) {
444 			xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
445 			thaw_bdev(sb->s_bdev, sb);
446 		}
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 void
471 xfs_do_force_shutdown(
472 	struct xfs_mount *mp,
473 	int		flags,
474 	char		*fname,
475 	int		lnnum)
476 {
477 	bool		logerror = flags & SHUTDOWN_LOG_IO_ERROR;
478 
479 	/*
480 	 * No need to duplicate efforts.
481 	 */
482 	if (XFS_FORCED_SHUTDOWN(mp) && !logerror)
483 		return;
484 
485 	/*
486 	 * This flags XFS_MOUNT_FS_SHUTDOWN, makes sure that we don't
487 	 * queue up anybody new on the log reservations, and wakes up
488 	 * everybody who's sleeping on log reservations to tell them
489 	 * the bad news.
490 	 */
491 	if (xfs_log_force_umount(mp, logerror))
492 		return;
493 
494 	if (flags & SHUTDOWN_FORCE_UMOUNT) {
495 		xfs_alert(mp,
496 "User initiated shutdown received. Shutting down filesystem");
497 		return;
498 	}
499 
500 	xfs_notice(mp,
501 "%s(0x%x) called from line %d of file %s. Return address = "PTR_FMT,
502 		__func__, flags, lnnum, fname, __return_address);
503 
504 	if (flags & SHUTDOWN_CORRUPT_INCORE) {
505 		xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
506 "Corruption of in-memory data detected.  Shutting down filesystem");
507 		if (XFS_ERRLEVEL_HIGH <= xfs_error_level)
508 			xfs_stack_trace();
509 	} else if (logerror) {
510 		xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_LOGERROR,
511 			"Log I/O Error Detected. Shutting down filesystem");
512 	} else if (flags & SHUTDOWN_DEVICE_REQ) {
513 		xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
514 			"All device paths lost. Shutting down filesystem");
515 	} else if (!(flags & SHUTDOWN_REMOTE_REQ)) {
516 		xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
517 			"I/O Error Detected. Shutting down filesystem");
518 	}
519 
520 	xfs_alert(mp,
521 		"Please unmount the filesystem and rectify the problem(s)");
522 }
523 
524 /*
525  * Reserve free space for per-AG metadata.
526  */
527 int
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 (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
538 		pag = xfs_perag_get(mp, agno);
539 		err2 = xfs_ag_resv_init(pag, NULL);
540 		xfs_perag_put(pag);
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 int
558 xfs_fs_unreserve_ag_blocks(
559 	struct xfs_mount	*mp)
560 {
561 	xfs_agnumber_t		agno;
562 	struct xfs_perag	*pag;
563 	int			error = 0;
564 	int			err2;
565 
566 	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
567 		pag = xfs_perag_get(mp, agno);
568 		err2 = xfs_ag_resv_free(pag);
569 		xfs_perag_put(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