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
26 static struct xfs_buf *
xfs_get_aghdr_buf(struct xfs_mount * mp,xfs_daddr_t blkno,size_t numblks,const struct xfs_buf_ops * ops)27 xfs_get_aghdr_buf(
28 struct xfs_mount *mp,
29 xfs_daddr_t blkno,
30 size_t numblks,
31 const struct xfs_buf_ops *ops)
32 {
33 struct xfs_buf *bp;
34
35 bp = xfs_buf_get_uncached(mp->m_ddev_targp, numblks, 0);
36 if (!bp)
37 return NULL;
38
39 xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
40 bp->b_bn = blkno;
41 bp->b_maps[0].bm_bn = blkno;
42 bp->b_ops = ops;
43
44 return bp;
45 }
46
is_log_ag(struct xfs_mount * mp,struct aghdr_init_data * id)47 static inline bool is_log_ag(struct xfs_mount *mp, struct aghdr_init_data *id)
48 {
49 return mp->m_sb.sb_logstart > 0 &&
50 id->agno == XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart);
51 }
52
53 /*
54 * Generic btree root block init function
55 */
56 static void
xfs_btroot_init(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)57 xfs_btroot_init(
58 struct xfs_mount *mp,
59 struct xfs_buf *bp,
60 struct aghdr_init_data *id)
61 {
62 xfs_btree_init_block(mp, bp, id->type, 0, 0, id->agno);
63 }
64
65 /* Finish initializing a free space btree. */
66 static void
xfs_freesp_init_recs(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)67 xfs_freesp_init_recs(
68 struct xfs_mount *mp,
69 struct xfs_buf *bp,
70 struct aghdr_init_data *id)
71 {
72 struct xfs_alloc_rec *arec;
73 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
74
75 arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
76 arec->ar_startblock = cpu_to_be32(mp->m_ag_prealloc_blocks);
77
78 if (is_log_ag(mp, id)) {
79 struct xfs_alloc_rec *nrec;
80 xfs_agblock_t start = XFS_FSB_TO_AGBNO(mp,
81 mp->m_sb.sb_logstart);
82
83 ASSERT(start >= mp->m_ag_prealloc_blocks);
84 if (start != mp->m_ag_prealloc_blocks) {
85 /*
86 * Modify first record to pad stripe align of log
87 */
88 arec->ar_blockcount = cpu_to_be32(start -
89 mp->m_ag_prealloc_blocks);
90 nrec = arec + 1;
91
92 /*
93 * Insert second record at start of internal log
94 * which then gets trimmed.
95 */
96 nrec->ar_startblock = cpu_to_be32(
97 be32_to_cpu(arec->ar_startblock) +
98 be32_to_cpu(arec->ar_blockcount));
99 arec = nrec;
100 be16_add_cpu(&block->bb_numrecs, 1);
101 }
102 /*
103 * Change record start to after the internal log
104 */
105 be32_add_cpu(&arec->ar_startblock, mp->m_sb.sb_logblocks);
106 }
107
108 /*
109 * Calculate the record block count and check for the case where
110 * the log might have consumed all available space in the AG. If
111 * so, reset the record count to 0 to avoid exposure of an invalid
112 * record start block.
113 */
114 arec->ar_blockcount = cpu_to_be32(id->agsize -
115 be32_to_cpu(arec->ar_startblock));
116 if (!arec->ar_blockcount)
117 block->bb_numrecs = 0;
118 }
119
120 /*
121 * Alloc btree root block init functions
122 */
123 static void
xfs_bnoroot_init(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)124 xfs_bnoroot_init(
125 struct xfs_mount *mp,
126 struct xfs_buf *bp,
127 struct aghdr_init_data *id)
128 {
129 xfs_btree_init_block(mp, bp, XFS_BTNUM_BNO, 0, 1, id->agno);
130 xfs_freesp_init_recs(mp, bp, id);
131 }
132
133 static void
xfs_cntroot_init(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)134 xfs_cntroot_init(
135 struct xfs_mount *mp,
136 struct xfs_buf *bp,
137 struct aghdr_init_data *id)
138 {
139 xfs_btree_init_block(mp, bp, XFS_BTNUM_CNT, 0, 1, id->agno);
140 xfs_freesp_init_recs(mp, bp, id);
141 }
142
143 /*
144 * Reverse map root block init
145 */
146 static void
xfs_rmaproot_init(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)147 xfs_rmaproot_init(
148 struct xfs_mount *mp,
149 struct xfs_buf *bp,
150 struct aghdr_init_data *id)
151 {
152 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
153 struct xfs_rmap_rec *rrec;
154
155 xfs_btree_init_block(mp, bp, XFS_BTNUM_RMAP, 0, 4, id->agno);
156
157 /*
158 * mark the AG header regions as static metadata The BNO
159 * btree block is the first block after the headers, so
160 * it's location defines the size of region the static
161 * metadata consumes.
162 *
163 * Note: unlike mkfs, we never have to account for log
164 * space when growing the data regions
165 */
166 rrec = XFS_RMAP_REC_ADDR(block, 1);
167 rrec->rm_startblock = 0;
168 rrec->rm_blockcount = cpu_to_be32(XFS_BNO_BLOCK(mp));
169 rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_FS);
170 rrec->rm_offset = 0;
171
172 /* account freespace btree root blocks */
173 rrec = XFS_RMAP_REC_ADDR(block, 2);
174 rrec->rm_startblock = cpu_to_be32(XFS_BNO_BLOCK(mp));
175 rrec->rm_blockcount = cpu_to_be32(2);
176 rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_AG);
177 rrec->rm_offset = 0;
178
179 /* account inode btree root blocks */
180 rrec = XFS_RMAP_REC_ADDR(block, 3);
181 rrec->rm_startblock = cpu_to_be32(XFS_IBT_BLOCK(mp));
182 rrec->rm_blockcount = cpu_to_be32(XFS_RMAP_BLOCK(mp) -
183 XFS_IBT_BLOCK(mp));
184 rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_INOBT);
185 rrec->rm_offset = 0;
186
187 /* account for rmap btree root */
188 rrec = XFS_RMAP_REC_ADDR(block, 4);
189 rrec->rm_startblock = cpu_to_be32(XFS_RMAP_BLOCK(mp));
190 rrec->rm_blockcount = cpu_to_be32(1);
191 rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_AG);
192 rrec->rm_offset = 0;
193
194 /* account for refc btree root */
195 if (xfs_sb_version_hasreflink(&mp->m_sb)) {
196 rrec = XFS_RMAP_REC_ADDR(block, 5);
197 rrec->rm_startblock = cpu_to_be32(xfs_refc_block(mp));
198 rrec->rm_blockcount = cpu_to_be32(1);
199 rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_REFC);
200 rrec->rm_offset = 0;
201 be16_add_cpu(&block->bb_numrecs, 1);
202 }
203
204 /* account for the log space */
205 if (is_log_ag(mp, id)) {
206 rrec = XFS_RMAP_REC_ADDR(block,
207 be16_to_cpu(block->bb_numrecs) + 1);
208 rrec->rm_startblock = cpu_to_be32(
209 XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart));
210 rrec->rm_blockcount = cpu_to_be32(mp->m_sb.sb_logblocks);
211 rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_LOG);
212 rrec->rm_offset = 0;
213 be16_add_cpu(&block->bb_numrecs, 1);
214 }
215 }
216
217 /*
218 * Initialise new secondary superblocks with the pre-grow geometry, but mark
219 * them as "in progress" so we know they haven't yet been activated. This will
220 * get cleared when the update with the new geometry information is done after
221 * changes to the primary are committed. This isn't strictly necessary, but we
222 * get it for free with the delayed buffer write lists and it means we can tell
223 * if a grow operation didn't complete properly after the fact.
224 */
225 static void
xfs_sbblock_init(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)226 xfs_sbblock_init(
227 struct xfs_mount *mp,
228 struct xfs_buf *bp,
229 struct aghdr_init_data *id)
230 {
231 struct xfs_dsb *dsb = XFS_BUF_TO_SBP(bp);
232
233 xfs_sb_to_disk(dsb, &mp->m_sb);
234 dsb->sb_inprogress = 1;
235 }
236
237 static void
xfs_agfblock_init(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)238 xfs_agfblock_init(
239 struct xfs_mount *mp,
240 struct xfs_buf *bp,
241 struct aghdr_init_data *id)
242 {
243 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
244 xfs_extlen_t tmpsize;
245
246 agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
247 agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
248 agf->agf_seqno = cpu_to_be32(id->agno);
249 agf->agf_length = cpu_to_be32(id->agsize);
250 agf->agf_roots[XFS_BTNUM_BNOi] = cpu_to_be32(XFS_BNO_BLOCK(mp));
251 agf->agf_roots[XFS_BTNUM_CNTi] = cpu_to_be32(XFS_CNT_BLOCK(mp));
252 agf->agf_levels[XFS_BTNUM_BNOi] = cpu_to_be32(1);
253 agf->agf_levels[XFS_BTNUM_CNTi] = cpu_to_be32(1);
254 if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
255 agf->agf_roots[XFS_BTNUM_RMAPi] =
256 cpu_to_be32(XFS_RMAP_BLOCK(mp));
257 agf->agf_levels[XFS_BTNUM_RMAPi] = cpu_to_be32(1);
258 agf->agf_rmap_blocks = cpu_to_be32(1);
259 }
260
261 agf->agf_flfirst = cpu_to_be32(1);
262 agf->agf_fllast = 0;
263 agf->agf_flcount = 0;
264 tmpsize = id->agsize - mp->m_ag_prealloc_blocks;
265 agf->agf_freeblks = cpu_to_be32(tmpsize);
266 agf->agf_longest = cpu_to_be32(tmpsize);
267 if (xfs_sb_version_hascrc(&mp->m_sb))
268 uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid);
269 if (xfs_sb_version_hasreflink(&mp->m_sb)) {
270 agf->agf_refcount_root = cpu_to_be32(
271 xfs_refc_block(mp));
272 agf->agf_refcount_level = cpu_to_be32(1);
273 agf->agf_refcount_blocks = cpu_to_be32(1);
274 }
275
276 if (is_log_ag(mp, id)) {
277 int64_t logblocks = mp->m_sb.sb_logblocks;
278
279 be32_add_cpu(&agf->agf_freeblks, -logblocks);
280 agf->agf_longest = cpu_to_be32(id->agsize -
281 XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart) - logblocks);
282 }
283 }
284
285 static void
xfs_agflblock_init(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)286 xfs_agflblock_init(
287 struct xfs_mount *mp,
288 struct xfs_buf *bp,
289 struct aghdr_init_data *id)
290 {
291 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
292 __be32 *agfl_bno;
293 int bucket;
294
295 if (xfs_sb_version_hascrc(&mp->m_sb)) {
296 agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC);
297 agfl->agfl_seqno = cpu_to_be32(id->agno);
298 uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid);
299 }
300
301 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, bp);
302 for (bucket = 0; bucket < xfs_agfl_size(mp); bucket++)
303 agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);
304 }
305
306 static void
xfs_agiblock_init(struct xfs_mount * mp,struct xfs_buf * bp,struct aghdr_init_data * id)307 xfs_agiblock_init(
308 struct xfs_mount *mp,
309 struct xfs_buf *bp,
310 struct aghdr_init_data *id)
311 {
312 struct xfs_agi *agi = XFS_BUF_TO_AGI(bp);
313 int bucket;
314
315 agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
316 agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
317 agi->agi_seqno = cpu_to_be32(id->agno);
318 agi->agi_length = cpu_to_be32(id->agsize);
319 agi->agi_count = 0;
320 agi->agi_root = cpu_to_be32(XFS_IBT_BLOCK(mp));
321 agi->agi_level = cpu_to_be32(1);
322 agi->agi_freecount = 0;
323 agi->agi_newino = cpu_to_be32(NULLAGINO);
324 agi->agi_dirino = cpu_to_be32(NULLAGINO);
325 if (xfs_sb_version_hascrc(&mp->m_sb))
326 uuid_copy(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid);
327 if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
328 agi->agi_free_root = cpu_to_be32(XFS_FIBT_BLOCK(mp));
329 agi->agi_free_level = cpu_to_be32(1);
330 }
331 for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
332 agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
333 }
334
335 typedef void (*aghdr_init_work_f)(struct xfs_mount *mp, struct xfs_buf *bp,
336 struct aghdr_init_data *id);
337 static int
xfs_ag_init_hdr(struct xfs_mount * mp,struct aghdr_init_data * id,aghdr_init_work_f work,const struct xfs_buf_ops * ops)338 xfs_ag_init_hdr(
339 struct xfs_mount *mp,
340 struct aghdr_init_data *id,
341 aghdr_init_work_f work,
342 const struct xfs_buf_ops *ops)
343
344 {
345 struct xfs_buf *bp;
346
347 bp = xfs_get_aghdr_buf(mp, id->daddr, id->numblks, ops);
348 if (!bp)
349 return -ENOMEM;
350
351 (*work)(mp, bp, id);
352
353 xfs_buf_delwri_queue(bp, &id->buffer_list);
354 xfs_buf_relse(bp);
355 return 0;
356 }
357
358 struct xfs_aghdr_grow_data {
359 xfs_daddr_t daddr;
360 size_t numblks;
361 const struct xfs_buf_ops *ops;
362 aghdr_init_work_f work;
363 xfs_btnum_t type;
364 bool need_init;
365 };
366
367 /*
368 * Prepare new AG headers to be written to disk. We use uncached buffers here,
369 * as it is assumed these new AG headers are currently beyond the currently
370 * valid filesystem address space. Using cached buffers would trip over EOFS
371 * corruption detection alogrithms in the buffer cache lookup routines.
372 *
373 * This is a non-transactional function, but the prepared buffers are added to a
374 * delayed write buffer list supplied by the caller so they can submit them to
375 * disk and wait on them as required.
376 */
377 int
xfs_ag_init_headers(struct xfs_mount * mp,struct aghdr_init_data * id)378 xfs_ag_init_headers(
379 struct xfs_mount *mp,
380 struct aghdr_init_data *id)
381
382 {
383 struct xfs_aghdr_grow_data aghdr_data[] = {
384 { /* SB */
385 .daddr = XFS_AG_DADDR(mp, id->agno, XFS_SB_DADDR),
386 .numblks = XFS_FSS_TO_BB(mp, 1),
387 .ops = &xfs_sb_buf_ops,
388 .work = &xfs_sbblock_init,
389 .need_init = true
390 },
391 { /* AGF */
392 .daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGF_DADDR(mp)),
393 .numblks = XFS_FSS_TO_BB(mp, 1),
394 .ops = &xfs_agf_buf_ops,
395 .work = &xfs_agfblock_init,
396 .need_init = true
397 },
398 { /* AGFL */
399 .daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGFL_DADDR(mp)),
400 .numblks = XFS_FSS_TO_BB(mp, 1),
401 .ops = &xfs_agfl_buf_ops,
402 .work = &xfs_agflblock_init,
403 .need_init = true
404 },
405 { /* AGI */
406 .daddr = XFS_AG_DADDR(mp, id->agno, XFS_AGI_DADDR(mp)),
407 .numblks = XFS_FSS_TO_BB(mp, 1),
408 .ops = &xfs_agi_buf_ops,
409 .work = &xfs_agiblock_init,
410 .need_init = true
411 },
412 { /* BNO root block */
413 .daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_BNO_BLOCK(mp)),
414 .numblks = BTOBB(mp->m_sb.sb_blocksize),
415 .ops = &xfs_bnobt_buf_ops,
416 .work = &xfs_bnoroot_init,
417 .need_init = true
418 },
419 { /* CNT root block */
420 .daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_CNT_BLOCK(mp)),
421 .numblks = BTOBB(mp->m_sb.sb_blocksize),
422 .ops = &xfs_cntbt_buf_ops,
423 .work = &xfs_cntroot_init,
424 .need_init = true
425 },
426 { /* INO root block */
427 .daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_IBT_BLOCK(mp)),
428 .numblks = BTOBB(mp->m_sb.sb_blocksize),
429 .ops = &xfs_inobt_buf_ops,
430 .work = &xfs_btroot_init,
431 .type = XFS_BTNUM_INO,
432 .need_init = true
433 },
434 { /* FINO root block */
435 .daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_FIBT_BLOCK(mp)),
436 .numblks = BTOBB(mp->m_sb.sb_blocksize),
437 .ops = &xfs_finobt_buf_ops,
438 .work = &xfs_btroot_init,
439 .type = XFS_BTNUM_FINO,
440 .need_init = xfs_sb_version_hasfinobt(&mp->m_sb)
441 },
442 { /* RMAP root block */
443 .daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_RMAP_BLOCK(mp)),
444 .numblks = BTOBB(mp->m_sb.sb_blocksize),
445 .ops = &xfs_rmapbt_buf_ops,
446 .work = &xfs_rmaproot_init,
447 .need_init = xfs_sb_version_hasrmapbt(&mp->m_sb)
448 },
449 { /* REFC root block */
450 .daddr = XFS_AGB_TO_DADDR(mp, id->agno, xfs_refc_block(mp)),
451 .numblks = BTOBB(mp->m_sb.sb_blocksize),
452 .ops = &xfs_refcountbt_buf_ops,
453 .work = &xfs_btroot_init,
454 .type = XFS_BTNUM_REFC,
455 .need_init = xfs_sb_version_hasreflink(&mp->m_sb)
456 },
457 { /* NULL terminating block */
458 .daddr = XFS_BUF_DADDR_NULL,
459 }
460 };
461 struct xfs_aghdr_grow_data *dp;
462 int error = 0;
463
464 /* Account for AG free space in new AG */
465 id->nfree += id->agsize - mp->m_ag_prealloc_blocks;
466 for (dp = &aghdr_data[0]; dp->daddr != XFS_BUF_DADDR_NULL; dp++) {
467 if (!dp->need_init)
468 continue;
469
470 id->daddr = dp->daddr;
471 id->numblks = dp->numblks;
472 id->type = dp->type;
473 error = xfs_ag_init_hdr(mp, id, dp->work, dp->ops);
474 if (error)
475 break;
476 }
477 return error;
478 }
479
480 /*
481 * Extent the AG indicated by the @id by the length passed in
482 */
483 int
xfs_ag_extend_space(struct xfs_mount * mp,struct xfs_trans * tp,struct aghdr_init_data * id,xfs_extlen_t len)484 xfs_ag_extend_space(
485 struct xfs_mount *mp,
486 struct xfs_trans *tp,
487 struct aghdr_init_data *id,
488 xfs_extlen_t len)
489 {
490 struct xfs_buf *bp;
491 struct xfs_agi *agi;
492 struct xfs_agf *agf;
493 int error;
494
495 /*
496 * Change the agi length.
497 */
498 error = xfs_ialloc_read_agi(mp, tp, id->agno, &bp);
499 if (error)
500 return error;
501
502 agi = XFS_BUF_TO_AGI(bp);
503 be32_add_cpu(&agi->agi_length, len);
504 ASSERT(id->agno == mp->m_sb.sb_agcount - 1 ||
505 be32_to_cpu(agi->agi_length) == mp->m_sb.sb_agblocks);
506 xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
507
508 /*
509 * Change agf length.
510 */
511 error = xfs_alloc_read_agf(mp, tp, id->agno, 0, &bp);
512 if (error)
513 return error;
514
515 agf = XFS_BUF_TO_AGF(bp);
516 be32_add_cpu(&agf->agf_length, len);
517 ASSERT(agf->agf_length == agi->agi_length);
518 xfs_alloc_log_agf(tp, bp, XFS_AGF_LENGTH);
519
520 /*
521 * Free the new space.
522 *
523 * XFS_RMAP_OINFO_SKIP_UPDATE is used here to tell the rmap btree that
524 * this doesn't actually exist in the rmap btree.
525 */
526 error = xfs_rmap_free(tp, bp, id->agno,
527 be32_to_cpu(agf->agf_length) - len,
528 len, &XFS_RMAP_OINFO_SKIP_UPDATE);
529 if (error)
530 return error;
531
532 return xfs_free_extent(tp, XFS_AGB_TO_FSB(mp, id->agno,
533 be32_to_cpu(agf->agf_length) - len),
534 len, &XFS_RMAP_OINFO_SKIP_UPDATE,
535 XFS_AG_RESV_NONE);
536 }
537
538 /* Retrieve AG geometry. */
539 int
xfs_ag_get_geometry(struct xfs_mount * mp,xfs_agnumber_t agno,struct xfs_ag_geometry * ageo)540 xfs_ag_get_geometry(
541 struct xfs_mount *mp,
542 xfs_agnumber_t agno,
543 struct xfs_ag_geometry *ageo)
544 {
545 struct xfs_buf *agi_bp;
546 struct xfs_buf *agf_bp;
547 struct xfs_agi *agi;
548 struct xfs_agf *agf;
549 struct xfs_perag *pag;
550 unsigned int freeblks;
551 int error;
552
553 if (agno >= mp->m_sb.sb_agcount)
554 return -EINVAL;
555
556 /* Lock the AG headers. */
557 error = xfs_ialloc_read_agi(mp, NULL, agno, &agi_bp);
558 if (error)
559 return error;
560 error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agf_bp);
561 if (error)
562 goto out_agi;
563 pag = xfs_perag_get(mp, agno);
564
565 /* Fill out form. */
566 memset(ageo, 0, sizeof(*ageo));
567 ageo->ag_number = agno;
568
569 agi = XFS_BUF_TO_AGI(agi_bp);
570 ageo->ag_icount = be32_to_cpu(agi->agi_count);
571 ageo->ag_ifree = be32_to_cpu(agi->agi_freecount);
572
573 agf = XFS_BUF_TO_AGF(agf_bp);
574 ageo->ag_length = be32_to_cpu(agf->agf_length);
575 freeblks = pag->pagf_freeblks +
576 pag->pagf_flcount +
577 pag->pagf_btreeblks -
578 xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE);
579 ageo->ag_freeblks = freeblks;
580 xfs_ag_geom_health(pag, ageo);
581
582 /* Release resources. */
583 xfs_perag_put(pag);
584 xfs_buf_relse(agf_bp);
585 out_agi:
586 xfs_buf_relse(agi_bp);
587 return error;
588 }
589