xref: /kernel/linux/linux-6.6/fs/xfs/libxfs/xfs_ag.c (revision 62306a36)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * Copyright (c) 2018 Red Hat, Inc.
5 * All rights reserved.
6 */
7
8#include "xfs.h"
9#include "xfs_fs.h"
10#include "xfs_shared.h"
11#include "xfs_format.h"
12#include "xfs_trans_resv.h"
13#include "xfs_bit.h"
14#include "xfs_sb.h"
15#include "xfs_mount.h"
16#include "xfs_btree.h"
17#include "xfs_alloc_btree.h"
18#include "xfs_rmap_btree.h"
19#include "xfs_alloc.h"
20#include "xfs_ialloc.h"
21#include "xfs_rmap.h"
22#include "xfs_ag.h"
23#include "xfs_ag_resv.h"
24#include "xfs_health.h"
25#include "xfs_error.h"
26#include "xfs_bmap.h"
27#include "xfs_defer.h"
28#include "xfs_log_format.h"
29#include "xfs_trans.h"
30#include "xfs_trace.h"
31#include "xfs_inode.h"
32#include "xfs_icache.h"
33
34
35/*
36 * Passive reference counting access wrappers to the perag structures.  If the
37 * per-ag structure is to be freed, the freeing code is responsible for cleaning
38 * up objects with passive references before freeing the structure. This is
39 * things like cached buffers.
40 */
41struct xfs_perag *
42xfs_perag_get(
43	struct xfs_mount	*mp,
44	xfs_agnumber_t		agno)
45{
46	struct xfs_perag	*pag;
47
48	rcu_read_lock();
49	pag = radix_tree_lookup(&mp->m_perag_tree, agno);
50	if (pag) {
51		trace_xfs_perag_get(pag, _RET_IP_);
52		ASSERT(atomic_read(&pag->pag_ref) >= 0);
53		atomic_inc(&pag->pag_ref);
54	}
55	rcu_read_unlock();
56	return pag;
57}
58
59/*
60 * search from @first to find the next perag with the given tag set.
61 */
62struct xfs_perag *
63xfs_perag_get_tag(
64	struct xfs_mount	*mp,
65	xfs_agnumber_t		first,
66	unsigned int		tag)
67{
68	struct xfs_perag	*pag;
69	int			found;
70
71	rcu_read_lock();
72	found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
73					(void **)&pag, first, 1, tag);
74	if (found <= 0) {
75		rcu_read_unlock();
76		return NULL;
77	}
78	trace_xfs_perag_get_tag(pag, _RET_IP_);
79	atomic_inc(&pag->pag_ref);
80	rcu_read_unlock();
81	return pag;
82}
83
84/* Get a passive reference to the given perag. */
85struct xfs_perag *
86xfs_perag_hold(
87	struct xfs_perag	*pag)
88{
89	ASSERT(atomic_read(&pag->pag_ref) > 0 ||
90	       atomic_read(&pag->pag_active_ref) > 0);
91
92	trace_xfs_perag_hold(pag, _RET_IP_);
93	atomic_inc(&pag->pag_ref);
94	return pag;
95}
96
97void
98xfs_perag_put(
99	struct xfs_perag	*pag)
100{
101	trace_xfs_perag_put(pag, _RET_IP_);
102	ASSERT(atomic_read(&pag->pag_ref) > 0);
103	atomic_dec(&pag->pag_ref);
104}
105
106/*
107 * Active references for perag structures. This is for short term access to the
108 * per ag structures for walking trees or accessing state. If an AG is being
109 * shrunk or is offline, then this will fail to find that AG and return NULL
110 * instead.
111 */
112struct xfs_perag *
113xfs_perag_grab(
114	struct xfs_mount	*mp,
115	xfs_agnumber_t		agno)
116{
117	struct xfs_perag	*pag;
118
119	rcu_read_lock();
120	pag = radix_tree_lookup(&mp->m_perag_tree, agno);
121	if (pag) {
122		trace_xfs_perag_grab(pag, _RET_IP_);
123		if (!atomic_inc_not_zero(&pag->pag_active_ref))
124			pag = NULL;
125	}
126	rcu_read_unlock();
127	return pag;
128}
129
130/*
131 * search from @first to find the next perag with the given tag set.
132 */
133struct xfs_perag *
134xfs_perag_grab_tag(
135	struct xfs_mount	*mp,
136	xfs_agnumber_t		first,
137	int			tag)
138{
139	struct xfs_perag	*pag;
140	int			found;
141
142	rcu_read_lock();
143	found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
144					(void **)&pag, first, 1, tag);
145	if (found <= 0) {
146		rcu_read_unlock();
147		return NULL;
148	}
149	trace_xfs_perag_grab_tag(pag, _RET_IP_);
150	if (!atomic_inc_not_zero(&pag->pag_active_ref))
151		pag = NULL;
152	rcu_read_unlock();
153	return pag;
154}
155
156void
157xfs_perag_rele(
158	struct xfs_perag	*pag)
159{
160	trace_xfs_perag_rele(pag, _RET_IP_);
161	if (atomic_dec_and_test(&pag->pag_active_ref))
162		wake_up(&pag->pag_active_wq);
163}
164
165/*
166 * xfs_initialize_perag_data
167 *
168 * Read in each per-ag structure so we can count up the number of
169 * allocated inodes, free inodes and used filesystem blocks as this
170 * information is no longer persistent in the superblock. Once we have
171 * this information, write it into the in-core superblock structure.
172 */
173int
174xfs_initialize_perag_data(
175	struct xfs_mount	*mp,
176	xfs_agnumber_t		agcount)
177{
178	xfs_agnumber_t		index;
179	struct xfs_perag	*pag;
180	struct xfs_sb		*sbp = &mp->m_sb;
181	uint64_t		ifree = 0;
182	uint64_t		ialloc = 0;
183	uint64_t		bfree = 0;
184	uint64_t		bfreelst = 0;
185	uint64_t		btree = 0;
186	uint64_t		fdblocks;
187	int			error = 0;
188
189	for (index = 0; index < agcount; index++) {
190		/*
191		 * Read the AGF and AGI buffers to populate the per-ag
192		 * structures for us.
193		 */
194		pag = xfs_perag_get(mp, index);
195		error = xfs_alloc_read_agf(pag, NULL, 0, NULL);
196		if (!error)
197			error = xfs_ialloc_read_agi(pag, NULL, NULL);
198		if (error) {
199			xfs_perag_put(pag);
200			return error;
201		}
202
203		ifree += pag->pagi_freecount;
204		ialloc += pag->pagi_count;
205		bfree += pag->pagf_freeblks;
206		bfreelst += pag->pagf_flcount;
207		btree += pag->pagf_btreeblks;
208		xfs_perag_put(pag);
209	}
210	fdblocks = bfree + bfreelst + btree;
211
212	/*
213	 * If the new summary counts are obviously incorrect, fail the
214	 * mount operation because that implies the AGFs are also corrupt.
215	 * Clear FS_COUNTERS so that we don't unmount with a dirty log, which
216	 * will prevent xfs_repair from fixing anything.
217	 */
218	if (fdblocks > sbp->sb_dblocks || ifree > ialloc) {
219		xfs_alert(mp, "AGF corruption. Please run xfs_repair.");
220		error = -EFSCORRUPTED;
221		goto out;
222	}
223
224	/* Overwrite incore superblock counters with just-read data */
225	spin_lock(&mp->m_sb_lock);
226	sbp->sb_ifree = ifree;
227	sbp->sb_icount = ialloc;
228	sbp->sb_fdblocks = fdblocks;
229	spin_unlock(&mp->m_sb_lock);
230
231	xfs_reinit_percpu_counters(mp);
232out:
233	xfs_fs_mark_healthy(mp, XFS_SICK_FS_COUNTERS);
234	return error;
235}
236
237STATIC void
238__xfs_free_perag(
239	struct rcu_head	*head)
240{
241	struct xfs_perag *pag = container_of(head, struct xfs_perag, rcu_head);
242
243	ASSERT(!delayed_work_pending(&pag->pag_blockgc_work));
244	kmem_free(pag);
245}
246
247/*
248 * Free up the per-ag resources associated with the mount structure.
249 */
250void
251xfs_free_perag(
252	struct xfs_mount	*mp)
253{
254	struct xfs_perag	*pag;
255	xfs_agnumber_t		agno;
256
257	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
258		spin_lock(&mp->m_perag_lock);
259		pag = radix_tree_delete(&mp->m_perag_tree, agno);
260		spin_unlock(&mp->m_perag_lock);
261		ASSERT(pag);
262		XFS_IS_CORRUPT(pag->pag_mount, atomic_read(&pag->pag_ref) != 0);
263		xfs_defer_drain_free(&pag->pag_intents_drain);
264
265		cancel_delayed_work_sync(&pag->pag_blockgc_work);
266		xfs_buf_hash_destroy(pag);
267
268		/* drop the mount's active reference */
269		xfs_perag_rele(pag);
270		XFS_IS_CORRUPT(pag->pag_mount,
271				atomic_read(&pag->pag_active_ref) != 0);
272		call_rcu(&pag->rcu_head, __xfs_free_perag);
273	}
274}
275
276/* Find the size of the AG, in blocks. */
277static xfs_agblock_t
278__xfs_ag_block_count(
279	struct xfs_mount	*mp,
280	xfs_agnumber_t		agno,
281	xfs_agnumber_t		agcount,
282	xfs_rfsblock_t		dblocks)
283{
284	ASSERT(agno < agcount);
285
286	if (agno < agcount - 1)
287		return mp->m_sb.sb_agblocks;
288	return dblocks - (agno * mp->m_sb.sb_agblocks);
289}
290
291xfs_agblock_t
292xfs_ag_block_count(
293	struct xfs_mount	*mp,
294	xfs_agnumber_t		agno)
295{
296	return __xfs_ag_block_count(mp, agno, mp->m_sb.sb_agcount,
297			mp->m_sb.sb_dblocks);
298}
299
300/* Calculate the first and last possible inode number in an AG. */
301static void
302__xfs_agino_range(
303	struct xfs_mount	*mp,
304	xfs_agblock_t		eoag,
305	xfs_agino_t		*first,
306	xfs_agino_t		*last)
307{
308	xfs_agblock_t		bno;
309
310	/*
311	 * Calculate the first inode, which will be in the first
312	 * cluster-aligned block after the AGFL.
313	 */
314	bno = round_up(XFS_AGFL_BLOCK(mp) + 1, M_IGEO(mp)->cluster_align);
315	*first = XFS_AGB_TO_AGINO(mp, bno);
316
317	/*
318	 * Calculate the last inode, which will be at the end of the
319	 * last (aligned) cluster that can be allocated in the AG.
320	 */
321	bno = round_down(eoag, M_IGEO(mp)->cluster_align);
322	*last = XFS_AGB_TO_AGINO(mp, bno) - 1;
323}
324
325void
326xfs_agino_range(
327	struct xfs_mount	*mp,
328	xfs_agnumber_t		agno,
329	xfs_agino_t		*first,
330	xfs_agino_t		*last)
331{
332	return __xfs_agino_range(mp, xfs_ag_block_count(mp, agno), first, last);
333}
334
335int
336xfs_initialize_perag(
337	struct xfs_mount	*mp,
338	xfs_agnumber_t		agcount,
339	xfs_rfsblock_t		dblocks,
340	xfs_agnumber_t		*maxagi)
341{
342	struct xfs_perag	*pag;
343	xfs_agnumber_t		index;
344	xfs_agnumber_t		first_initialised = NULLAGNUMBER;
345	int			error;
346
347	/*
348	 * Walk the current per-ag tree so we don't try to initialise AGs
349	 * that already exist (growfs case). Allocate and insert all the
350	 * AGs we don't find ready for initialisation.
351	 */
352	for (index = 0; index < agcount; index++) {
353		pag = xfs_perag_get(mp, index);
354		if (pag) {
355			xfs_perag_put(pag);
356			continue;
357		}
358
359		pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
360		if (!pag) {
361			error = -ENOMEM;
362			goto out_unwind_new_pags;
363		}
364		pag->pag_agno = index;
365		pag->pag_mount = mp;
366
367		error = radix_tree_preload(GFP_NOFS);
368		if (error)
369			goto out_free_pag;
370
371		spin_lock(&mp->m_perag_lock);
372		if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
373			WARN_ON_ONCE(1);
374			spin_unlock(&mp->m_perag_lock);
375			radix_tree_preload_end();
376			error = -EEXIST;
377			goto out_free_pag;
378		}
379		spin_unlock(&mp->m_perag_lock);
380		radix_tree_preload_end();
381
382#ifdef __KERNEL__
383		/* Place kernel structure only init below this point. */
384		spin_lock_init(&pag->pag_ici_lock);
385		spin_lock_init(&pag->pagb_lock);
386		spin_lock_init(&pag->pag_state_lock);
387		INIT_DELAYED_WORK(&pag->pag_blockgc_work, xfs_blockgc_worker);
388		INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
389		xfs_defer_drain_init(&pag->pag_intents_drain);
390		init_waitqueue_head(&pag->pagb_wait);
391		init_waitqueue_head(&pag->pag_active_wq);
392		pag->pagb_count = 0;
393		pag->pagb_tree = RB_ROOT;
394#endif /* __KERNEL__ */
395
396		error = xfs_buf_hash_init(pag);
397		if (error)
398			goto out_remove_pag;
399
400		/* Active ref owned by mount indicates AG is online. */
401		atomic_set(&pag->pag_active_ref, 1);
402
403		/* first new pag is fully initialized */
404		if (first_initialised == NULLAGNUMBER)
405			first_initialised = index;
406
407		/*
408		 * Pre-calculated geometry
409		 */
410		pag->block_count = __xfs_ag_block_count(mp, index, agcount,
411				dblocks);
412		pag->min_block = XFS_AGFL_BLOCK(mp);
413		__xfs_agino_range(mp, pag->block_count, &pag->agino_min,
414				&pag->agino_max);
415	}
416
417	index = xfs_set_inode_alloc(mp, agcount);
418
419	if (maxagi)
420		*maxagi = index;
421
422	mp->m_ag_prealloc_blocks = xfs_prealloc_blocks(mp);
423	return 0;
424
425out_remove_pag:
426	xfs_defer_drain_free(&pag->pag_intents_drain);
427	radix_tree_delete(&mp->m_perag_tree, index);
428out_free_pag:
429	kmem_free(pag);
430out_unwind_new_pags:
431	/* unwind any prior newly initialized pags */
432	for (index = first_initialised; index < agcount; index++) {
433		pag = radix_tree_delete(&mp->m_perag_tree, index);
434		if (!pag)
435			break;
436		xfs_buf_hash_destroy(pag);
437		xfs_defer_drain_free(&pag->pag_intents_drain);
438		kmem_free(pag);
439	}
440	return error;
441}
442
443static int
444xfs_get_aghdr_buf(
445	struct xfs_mount	*mp,
446	xfs_daddr_t		blkno,
447	size_t			numblks,
448	struct xfs_buf		**bpp,
449	const struct xfs_buf_ops *ops)
450{
451	struct xfs_buf		*bp;
452	int			error;
453
454	error = xfs_buf_get_uncached(mp->m_ddev_targp, numblks, 0, &bp);
455	if (error)
456		return error;
457
458	bp->b_maps[0].bm_bn = blkno;
459	bp->b_ops = ops;
460
461	*bpp = bp;
462	return 0;
463}
464
465/*
466 * Generic btree root block init function
467 */
468static void
469xfs_btroot_init(
470	struct xfs_mount	*mp,
471	struct xfs_buf		*bp,
472	struct aghdr_init_data	*id)
473{
474	xfs_btree_init_block(mp, bp, id->type, 0, 0, id->agno);
475}
476
477/* Finish initializing a free space btree. */
478static void
479xfs_freesp_init_recs(
480	struct xfs_mount	*mp,
481	struct xfs_buf		*bp,
482	struct aghdr_init_data	*id)
483{
484	struct xfs_alloc_rec	*arec;
485	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
486
487	arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
488	arec->ar_startblock = cpu_to_be32(mp->m_ag_prealloc_blocks);
489
490	if (xfs_ag_contains_log(mp, id->agno)) {
491		struct xfs_alloc_rec	*nrec;
492		xfs_agblock_t		start = XFS_FSB_TO_AGBNO(mp,
493							mp->m_sb.sb_logstart);
494
495		ASSERT(start >= mp->m_ag_prealloc_blocks);
496		if (start != mp->m_ag_prealloc_blocks) {
497			/*
498			 * Modify first record to pad stripe align of log and
499			 * bump the record count.
500			 */
501			arec->ar_blockcount = cpu_to_be32(start -
502						mp->m_ag_prealloc_blocks);
503			be16_add_cpu(&block->bb_numrecs, 1);
504			nrec = arec + 1;
505
506			/*
507			 * Insert second record at start of internal log
508			 * which then gets trimmed.
509			 */
510			nrec->ar_startblock = cpu_to_be32(
511					be32_to_cpu(arec->ar_startblock) +
512					be32_to_cpu(arec->ar_blockcount));
513			arec = nrec;
514		}
515		/*
516		 * Change record start to after the internal log
517		 */
518		be32_add_cpu(&arec->ar_startblock, mp->m_sb.sb_logblocks);
519	}
520
521	/*
522	 * Calculate the block count of this record; if it is nonzero,
523	 * increment the record count.
524	 */
525	arec->ar_blockcount = cpu_to_be32(id->agsize -
526					  be32_to_cpu(arec->ar_startblock));
527	if (arec->ar_blockcount)
528		be16_add_cpu(&block->bb_numrecs, 1);
529}
530
531/*
532 * Alloc btree root block init functions
533 */
534static void
535xfs_bnoroot_init(
536	struct xfs_mount	*mp,
537	struct xfs_buf		*bp,
538	struct aghdr_init_data	*id)
539{
540	xfs_btree_init_block(mp, bp, XFS_BTNUM_BNO, 0, 0, id->agno);
541	xfs_freesp_init_recs(mp, bp, id);
542}
543
544static void
545xfs_cntroot_init(
546	struct xfs_mount	*mp,
547	struct xfs_buf		*bp,
548	struct aghdr_init_data	*id)
549{
550	xfs_btree_init_block(mp, bp, XFS_BTNUM_CNT, 0, 0, id->agno);
551	xfs_freesp_init_recs(mp, bp, id);
552}
553
554/*
555 * Reverse map root block init
556 */
557static void
558xfs_rmaproot_init(
559	struct xfs_mount	*mp,
560	struct xfs_buf		*bp,
561	struct aghdr_init_data	*id)
562{
563	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
564	struct xfs_rmap_rec	*rrec;
565
566	xfs_btree_init_block(mp, bp, XFS_BTNUM_RMAP, 0, 4, id->agno);
567
568	/*
569	 * mark the AG header regions as static metadata The BNO
570	 * btree block is the first block after the headers, so
571	 * it's location defines the size of region the static
572	 * metadata consumes.
573	 *
574	 * Note: unlike mkfs, we never have to account for log
575	 * space when growing the data regions
576	 */
577	rrec = XFS_RMAP_REC_ADDR(block, 1);
578	rrec->rm_startblock = 0;
579	rrec->rm_blockcount = cpu_to_be32(XFS_BNO_BLOCK(mp));
580	rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_FS);
581	rrec->rm_offset = 0;
582
583	/* account freespace btree root blocks */
584	rrec = XFS_RMAP_REC_ADDR(block, 2);
585	rrec->rm_startblock = cpu_to_be32(XFS_BNO_BLOCK(mp));
586	rrec->rm_blockcount = cpu_to_be32(2);
587	rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_AG);
588	rrec->rm_offset = 0;
589
590	/* account inode btree root blocks */
591	rrec = XFS_RMAP_REC_ADDR(block, 3);
592	rrec->rm_startblock = cpu_to_be32(XFS_IBT_BLOCK(mp));
593	rrec->rm_blockcount = cpu_to_be32(XFS_RMAP_BLOCK(mp) -
594					  XFS_IBT_BLOCK(mp));
595	rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_INOBT);
596	rrec->rm_offset = 0;
597
598	/* account for rmap btree root */
599	rrec = XFS_RMAP_REC_ADDR(block, 4);
600	rrec->rm_startblock = cpu_to_be32(XFS_RMAP_BLOCK(mp));
601	rrec->rm_blockcount = cpu_to_be32(1);
602	rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_AG);
603	rrec->rm_offset = 0;
604
605	/* account for refc btree root */
606	if (xfs_has_reflink(mp)) {
607		rrec = XFS_RMAP_REC_ADDR(block, 5);
608		rrec->rm_startblock = cpu_to_be32(xfs_refc_block(mp));
609		rrec->rm_blockcount = cpu_to_be32(1);
610		rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_REFC);
611		rrec->rm_offset = 0;
612		be16_add_cpu(&block->bb_numrecs, 1);
613	}
614
615	/* account for the log space */
616	if (xfs_ag_contains_log(mp, id->agno)) {
617		rrec = XFS_RMAP_REC_ADDR(block,
618				be16_to_cpu(block->bb_numrecs) + 1);
619		rrec->rm_startblock = cpu_to_be32(
620				XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart));
621		rrec->rm_blockcount = cpu_to_be32(mp->m_sb.sb_logblocks);
622		rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_LOG);
623		rrec->rm_offset = 0;
624		be16_add_cpu(&block->bb_numrecs, 1);
625	}
626}
627
628/*
629 * Initialise new secondary superblocks with the pre-grow geometry, but mark
630 * them as "in progress" so we know they haven't yet been activated. This will
631 * get cleared when the update with the new geometry information is done after
632 * changes to the primary are committed. This isn't strictly necessary, but we
633 * get it for free with the delayed buffer write lists and it means we can tell
634 * if a grow operation didn't complete properly after the fact.
635 */
636static void
637xfs_sbblock_init(
638	struct xfs_mount	*mp,
639	struct xfs_buf		*bp,
640	struct aghdr_init_data	*id)
641{
642	struct xfs_dsb		*dsb = bp->b_addr;
643
644	xfs_sb_to_disk(dsb, &mp->m_sb);
645	dsb->sb_inprogress = 1;
646}
647
648static void
649xfs_agfblock_init(
650	struct xfs_mount	*mp,
651	struct xfs_buf		*bp,
652	struct aghdr_init_data	*id)
653{
654	struct xfs_agf		*agf = bp->b_addr;
655	xfs_extlen_t		tmpsize;
656
657	agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
658	agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
659	agf->agf_seqno = cpu_to_be32(id->agno);
660	agf->agf_length = cpu_to_be32(id->agsize);
661	agf->agf_roots[XFS_BTNUM_BNOi] = cpu_to_be32(XFS_BNO_BLOCK(mp));
662	agf->agf_roots[XFS_BTNUM_CNTi] = cpu_to_be32(XFS_CNT_BLOCK(mp));
663	agf->agf_levels[XFS_BTNUM_BNOi] = cpu_to_be32(1);
664	agf->agf_levels[XFS_BTNUM_CNTi] = cpu_to_be32(1);
665	if (xfs_has_rmapbt(mp)) {
666		agf->agf_roots[XFS_BTNUM_RMAPi] =
667					cpu_to_be32(XFS_RMAP_BLOCK(mp));
668		agf->agf_levels[XFS_BTNUM_RMAPi] = cpu_to_be32(1);
669		agf->agf_rmap_blocks = cpu_to_be32(1);
670	}
671
672	agf->agf_flfirst = cpu_to_be32(1);
673	agf->agf_fllast = 0;
674	agf->agf_flcount = 0;
675	tmpsize = id->agsize - mp->m_ag_prealloc_blocks;
676	agf->agf_freeblks = cpu_to_be32(tmpsize);
677	agf->agf_longest = cpu_to_be32(tmpsize);
678	if (xfs_has_crc(mp))
679		uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid);
680	if (xfs_has_reflink(mp)) {
681		agf->agf_refcount_root = cpu_to_be32(
682				xfs_refc_block(mp));
683		agf->agf_refcount_level = cpu_to_be32(1);
684		agf->agf_refcount_blocks = cpu_to_be32(1);
685	}
686
687	if (xfs_ag_contains_log(mp, id->agno)) {
688		int64_t	logblocks = mp->m_sb.sb_logblocks;
689
690		be32_add_cpu(&agf->agf_freeblks, -logblocks);
691		agf->agf_longest = cpu_to_be32(id->agsize -
692			XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart) - logblocks);
693	}
694}
695
696static void
697xfs_agflblock_init(
698	struct xfs_mount	*mp,
699	struct xfs_buf		*bp,
700	struct aghdr_init_data	*id)
701{
702	struct xfs_agfl		*agfl = XFS_BUF_TO_AGFL(bp);
703	__be32			*agfl_bno;
704	int			bucket;
705
706	if (xfs_has_crc(mp)) {
707		agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC);
708		agfl->agfl_seqno = cpu_to_be32(id->agno);
709		uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid);
710	}
711
712	agfl_bno = xfs_buf_to_agfl_bno(bp);
713	for (bucket = 0; bucket < xfs_agfl_size(mp); bucket++)
714		agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);
715}
716
717static void
718xfs_agiblock_init(
719	struct xfs_mount	*mp,
720	struct xfs_buf		*bp,
721	struct aghdr_init_data	*id)
722{
723	struct xfs_agi		*agi = bp->b_addr;
724	int			bucket;
725
726	agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
727	agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
728	agi->agi_seqno = cpu_to_be32(id->agno);
729	agi->agi_length = cpu_to_be32(id->agsize);
730	agi->agi_count = 0;
731	agi->agi_root = cpu_to_be32(XFS_IBT_BLOCK(mp));
732	agi->agi_level = cpu_to_be32(1);
733	agi->agi_freecount = 0;
734	agi->agi_newino = cpu_to_be32(NULLAGINO);
735	agi->agi_dirino = cpu_to_be32(NULLAGINO);
736	if (xfs_has_crc(mp))
737		uuid_copy(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid);
738	if (xfs_has_finobt(mp)) {
739		agi->agi_free_root = cpu_to_be32(XFS_FIBT_BLOCK(mp));
740		agi->agi_free_level = cpu_to_be32(1);
741	}
742	for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
743		agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
744	if (xfs_has_inobtcounts(mp)) {
745		agi->agi_iblocks = cpu_to_be32(1);
746		if (xfs_has_finobt(mp))
747			agi->agi_fblocks = cpu_to_be32(1);
748	}
749}
750
751typedef void (*aghdr_init_work_f)(struct xfs_mount *mp, struct xfs_buf *bp,
752				  struct aghdr_init_data *id);
753static int
754xfs_ag_init_hdr(
755	struct xfs_mount	*mp,
756	struct aghdr_init_data	*id,
757	aghdr_init_work_f	work,
758	const struct xfs_buf_ops *ops)
759{
760	struct xfs_buf		*bp;
761	int			error;
762
763	error = xfs_get_aghdr_buf(mp, id->daddr, id->numblks, &bp, ops);
764	if (error)
765		return error;
766
767	(*work)(mp, bp, id);
768
769	xfs_buf_delwri_queue(bp, &id->buffer_list);
770	xfs_buf_relse(bp);
771	return 0;
772}
773
774struct xfs_aghdr_grow_data {
775	xfs_daddr_t		daddr;
776	size_t			numblks;
777	const struct xfs_buf_ops *ops;
778	aghdr_init_work_f	work;
779	xfs_btnum_t		type;
780	bool			need_init;
781};
782
783/*
784 * Prepare new AG headers to be written to disk. We use uncached buffers here,
785 * as it is assumed these new AG headers are currently beyond the currently
786 * valid filesystem address space. Using cached buffers would trip over EOFS
787 * corruption detection alogrithms in the buffer cache lookup routines.
788 *
789 * This is a non-transactional function, but the prepared buffers are added to a
790 * delayed write buffer list supplied by the caller so they can submit them to
791 * disk and wait on them as required.
792 */
793int
794xfs_ag_init_headers(
795	struct xfs_mount	*mp,
796	struct aghdr_init_data	*id)
797
798{
799	struct xfs_aghdr_grow_data aghdr_data[] = {
800	{ /* SB */
801		.daddr = XFS_AG_DADDR(mp, id->agno, XFS_SB_DADDR),
802		.numblks = XFS_FSS_TO_BB(mp, 1),
803		.ops = &xfs_sb_buf_ops,
804		.work = &xfs_sbblock_init,
805		.need_init = true
806	},
807	{ /* AGF */
808		.daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGF_DADDR(mp)),
809		.numblks = XFS_FSS_TO_BB(mp, 1),
810		.ops = &xfs_agf_buf_ops,
811		.work = &xfs_agfblock_init,
812		.need_init = true
813	},
814	{ /* AGFL */
815		.daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGFL_DADDR(mp)),
816		.numblks = XFS_FSS_TO_BB(mp, 1),
817		.ops = &xfs_agfl_buf_ops,
818		.work = &xfs_agflblock_init,
819		.need_init = true
820	},
821	{ /* AGI */
822		.daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGI_DADDR(mp)),
823		.numblks = XFS_FSS_TO_BB(mp, 1),
824		.ops = &xfs_agi_buf_ops,
825		.work = &xfs_agiblock_init,
826		.need_init = true
827	},
828	{ /* BNO root block */
829		.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_BNO_BLOCK(mp)),
830		.numblks = BTOBB(mp->m_sb.sb_blocksize),
831		.ops = &xfs_bnobt_buf_ops,
832		.work = &xfs_bnoroot_init,
833		.need_init = true
834	},
835	{ /* CNT root block */
836		.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_CNT_BLOCK(mp)),
837		.numblks = BTOBB(mp->m_sb.sb_blocksize),
838		.ops = &xfs_cntbt_buf_ops,
839		.work = &xfs_cntroot_init,
840		.need_init = true
841	},
842	{ /* INO root block */
843		.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_IBT_BLOCK(mp)),
844		.numblks = BTOBB(mp->m_sb.sb_blocksize),
845		.ops = &xfs_inobt_buf_ops,
846		.work = &xfs_btroot_init,
847		.type = XFS_BTNUM_INO,
848		.need_init = true
849	},
850	{ /* FINO root block */
851		.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_FIBT_BLOCK(mp)),
852		.numblks = BTOBB(mp->m_sb.sb_blocksize),
853		.ops = &xfs_finobt_buf_ops,
854		.work = &xfs_btroot_init,
855		.type = XFS_BTNUM_FINO,
856		.need_init =  xfs_has_finobt(mp)
857	},
858	{ /* RMAP root block */
859		.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_RMAP_BLOCK(mp)),
860		.numblks = BTOBB(mp->m_sb.sb_blocksize),
861		.ops = &xfs_rmapbt_buf_ops,
862		.work = &xfs_rmaproot_init,
863		.need_init = xfs_has_rmapbt(mp)
864	},
865	{ /* REFC root block */
866		.daddr = XFS_AGB_TO_DADDR(mp, id->agno, xfs_refc_block(mp)),
867		.numblks = BTOBB(mp->m_sb.sb_blocksize),
868		.ops = &xfs_refcountbt_buf_ops,
869		.work = &xfs_btroot_init,
870		.type = XFS_BTNUM_REFC,
871		.need_init = xfs_has_reflink(mp)
872	},
873	{ /* NULL terminating block */
874		.daddr = XFS_BUF_DADDR_NULL,
875	}
876	};
877	struct  xfs_aghdr_grow_data *dp;
878	int			error = 0;
879
880	/* Account for AG free space in new AG */
881	id->nfree += id->agsize - mp->m_ag_prealloc_blocks;
882	for (dp = &aghdr_data[0]; dp->daddr != XFS_BUF_DADDR_NULL; dp++) {
883		if (!dp->need_init)
884			continue;
885
886		id->daddr = dp->daddr;
887		id->numblks = dp->numblks;
888		id->type = dp->type;
889		error = xfs_ag_init_hdr(mp, id, dp->work, dp->ops);
890		if (error)
891			break;
892	}
893	return error;
894}
895
896int
897xfs_ag_shrink_space(
898	struct xfs_perag	*pag,
899	struct xfs_trans	**tpp,
900	xfs_extlen_t		delta)
901{
902	struct xfs_mount	*mp = pag->pag_mount;
903	struct xfs_alloc_arg	args = {
904		.tp	= *tpp,
905		.mp	= mp,
906		.pag	= pag,
907		.minlen = delta,
908		.maxlen = delta,
909		.oinfo	= XFS_RMAP_OINFO_SKIP_UPDATE,
910		.resv	= XFS_AG_RESV_NONE,
911		.prod	= 1
912	};
913	struct xfs_buf		*agibp, *agfbp;
914	struct xfs_agi		*agi;
915	struct xfs_agf		*agf;
916	xfs_agblock_t		aglen;
917	int			error, err2;
918
919	ASSERT(pag->pag_agno == mp->m_sb.sb_agcount - 1);
920	error = xfs_ialloc_read_agi(pag, *tpp, &agibp);
921	if (error)
922		return error;
923
924	agi = agibp->b_addr;
925
926	error = xfs_alloc_read_agf(pag, *tpp, 0, &agfbp);
927	if (error)
928		return error;
929
930	agf = agfbp->b_addr;
931	aglen = be32_to_cpu(agi->agi_length);
932	/* some extra paranoid checks before we shrink the ag */
933	if (XFS_IS_CORRUPT(mp, agf->agf_length != agi->agi_length))
934		return -EFSCORRUPTED;
935	if (delta >= aglen)
936		return -EINVAL;
937
938	/*
939	 * Make sure that the last inode cluster cannot overlap with the new
940	 * end of the AG, even if it's sparse.
941	 */
942	error = xfs_ialloc_check_shrink(pag, *tpp, agibp, aglen - delta);
943	if (error)
944		return error;
945
946	/*
947	 * Disable perag reservations so it doesn't cause the allocation request
948	 * to fail. We'll reestablish reservation before we return.
949	 */
950	error = xfs_ag_resv_free(pag);
951	if (error)
952		return error;
953
954	/* internal log shouldn't also show up in the free space btrees */
955	error = xfs_alloc_vextent_exact_bno(&args,
956			XFS_AGB_TO_FSB(mp, pag->pag_agno, aglen - delta));
957	if (!error && args.agbno == NULLAGBLOCK)
958		error = -ENOSPC;
959
960	if (error) {
961		/*
962		 * if extent allocation fails, need to roll the transaction to
963		 * ensure that the AGFL fixup has been committed anyway.
964		 */
965		xfs_trans_bhold(*tpp, agfbp);
966		err2 = xfs_trans_roll(tpp);
967		if (err2)
968			return err2;
969		xfs_trans_bjoin(*tpp, agfbp);
970		goto resv_init_out;
971	}
972
973	/*
974	 * if successfully deleted from freespace btrees, need to confirm
975	 * per-AG reservation works as expected.
976	 */
977	be32_add_cpu(&agi->agi_length, -delta);
978	be32_add_cpu(&agf->agf_length, -delta);
979
980	err2 = xfs_ag_resv_init(pag, *tpp);
981	if (err2) {
982		be32_add_cpu(&agi->agi_length, delta);
983		be32_add_cpu(&agf->agf_length, delta);
984		if (err2 != -ENOSPC)
985			goto resv_err;
986
987		err2 = __xfs_free_extent_later(*tpp, args.fsbno, delta, NULL,
988				XFS_AG_RESV_NONE, true);
989		if (err2)
990			goto resv_err;
991
992		/*
993		 * Roll the transaction before trying to re-init the per-ag
994		 * reservation. The new transaction is clean so it will cancel
995		 * without any side effects.
996		 */
997		error = xfs_defer_finish(tpp);
998		if (error)
999			return error;
1000
1001		error = -ENOSPC;
1002		goto resv_init_out;
1003	}
1004
1005	/* Update perag geometry */
1006	pag->block_count -= delta;
1007	__xfs_agino_range(pag->pag_mount, pag->block_count, &pag->agino_min,
1008				&pag->agino_max);
1009
1010	xfs_ialloc_log_agi(*tpp, agibp, XFS_AGI_LENGTH);
1011	xfs_alloc_log_agf(*tpp, agfbp, XFS_AGF_LENGTH);
1012	return 0;
1013
1014resv_init_out:
1015	err2 = xfs_ag_resv_init(pag, *tpp);
1016	if (!err2)
1017		return error;
1018resv_err:
1019	xfs_warn(mp, "Error %d reserving per-AG metadata reserve pool.", err2);
1020	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1021	return err2;
1022}
1023
1024/*
1025 * Extent the AG indicated by the @id by the length passed in
1026 */
1027int
1028xfs_ag_extend_space(
1029	struct xfs_perag	*pag,
1030	struct xfs_trans	*tp,
1031	xfs_extlen_t		len)
1032{
1033	struct xfs_buf		*bp;
1034	struct xfs_agi		*agi;
1035	struct xfs_agf		*agf;
1036	int			error;
1037
1038	ASSERT(pag->pag_agno == pag->pag_mount->m_sb.sb_agcount - 1);
1039
1040	error = xfs_ialloc_read_agi(pag, tp, &bp);
1041	if (error)
1042		return error;
1043
1044	agi = bp->b_addr;
1045	be32_add_cpu(&agi->agi_length, len);
1046	xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
1047
1048	/*
1049	 * Change agf length.
1050	 */
1051	error = xfs_alloc_read_agf(pag, tp, 0, &bp);
1052	if (error)
1053		return error;
1054
1055	agf = bp->b_addr;
1056	be32_add_cpu(&agf->agf_length, len);
1057	ASSERT(agf->agf_length == agi->agi_length);
1058	xfs_alloc_log_agf(tp, bp, XFS_AGF_LENGTH);
1059
1060	/*
1061	 * Free the new space.
1062	 *
1063	 * XFS_RMAP_OINFO_SKIP_UPDATE is used here to tell the rmap btree that
1064	 * this doesn't actually exist in the rmap btree.
1065	 */
1066	error = xfs_rmap_free(tp, bp, pag, be32_to_cpu(agf->agf_length) - len,
1067				len, &XFS_RMAP_OINFO_SKIP_UPDATE);
1068	if (error)
1069		return error;
1070
1071	error = xfs_free_extent(tp, pag, be32_to_cpu(agf->agf_length) - len,
1072			len, &XFS_RMAP_OINFO_SKIP_UPDATE, XFS_AG_RESV_NONE);
1073	if (error)
1074		return error;
1075
1076	/* Update perag geometry */
1077	pag->block_count = be32_to_cpu(agf->agf_length);
1078	__xfs_agino_range(pag->pag_mount, pag->block_count, &pag->agino_min,
1079				&pag->agino_max);
1080	return 0;
1081}
1082
1083/* Retrieve AG geometry. */
1084int
1085xfs_ag_get_geometry(
1086	struct xfs_perag	*pag,
1087	struct xfs_ag_geometry	*ageo)
1088{
1089	struct xfs_buf		*agi_bp;
1090	struct xfs_buf		*agf_bp;
1091	struct xfs_agi		*agi;
1092	struct xfs_agf		*agf;
1093	unsigned int		freeblks;
1094	int			error;
1095
1096	/* Lock the AG headers. */
1097	error = xfs_ialloc_read_agi(pag, NULL, &agi_bp);
1098	if (error)
1099		return error;
1100	error = xfs_alloc_read_agf(pag, NULL, 0, &agf_bp);
1101	if (error)
1102		goto out_agi;
1103
1104	/* Fill out form. */
1105	memset(ageo, 0, sizeof(*ageo));
1106	ageo->ag_number = pag->pag_agno;
1107
1108	agi = agi_bp->b_addr;
1109	ageo->ag_icount = be32_to_cpu(agi->agi_count);
1110	ageo->ag_ifree = be32_to_cpu(agi->agi_freecount);
1111
1112	agf = agf_bp->b_addr;
1113	ageo->ag_length = be32_to_cpu(agf->agf_length);
1114	freeblks = pag->pagf_freeblks +
1115		   pag->pagf_flcount +
1116		   pag->pagf_btreeblks -
1117		   xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE);
1118	ageo->ag_freeblks = freeblks;
1119	xfs_ag_geom_health(pag, ageo);
1120
1121	/* Release resources. */
1122	xfs_buf_relse(agf_bp);
1123out_agi:
1124	xfs_buf_relse(agi_bp);
1125	return error;
1126}
1127