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1/*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_shared.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_bit.h"
25#include "xfs_inum.h"
26#include "xfs_sb.h"
27#include "xfs_ag.h"
28#include "xfs_mount.h"
29#include "xfs_inode.h"
30#include "xfs_btree.h"
31#include "xfs_ialloc.h"
32#include "xfs_ialloc_btree.h"
33#include "xfs_alloc.h"
34#include "xfs_rtalloc.h"
35#include "xfs_error.h"
36#include "xfs_bmap.h"
37#include "xfs_cksum.h"
38#include "xfs_trans.h"
39#include "xfs_buf_item.h"
40#include "xfs_icreate_item.h"
41#include "xfs_icache.h"
42#include "xfs_dinode.h"
43#include "xfs_trace.h"
44
45
46/*
47 * Allocation group level functions.
48 */
49static inline int
50xfs_ialloc_cluster_alignment(
51 xfs_alloc_arg_t *args)
52{
53 if (xfs_sb_version_hasalign(&args->mp->m_sb) &&
54 args->mp->m_sb.sb_inoalignmt >=
55 XFS_B_TO_FSBT(args->mp, args->mp->m_inode_cluster_size))
56 return args->mp->m_sb.sb_inoalignmt;
57 return 1;
58}
59
60/*
61 * Lookup a record by ino in the btree given by cur.
62 */
63int /* error */
64xfs_inobt_lookup(
65 struct xfs_btree_cur *cur, /* btree cursor */
66 xfs_agino_t ino, /* starting inode of chunk */
67 xfs_lookup_t dir, /* <=, >=, == */
68 int *stat) /* success/failure */
69{
70 cur->bc_rec.i.ir_startino = ino;
71 cur->bc_rec.i.ir_freecount = 0;
72 cur->bc_rec.i.ir_free = 0;
73 return xfs_btree_lookup(cur, dir, stat);
74}
75
76/*
77 * Update the record referred to by cur to the value given.
78 * This either works (return 0) or gets an EFSCORRUPTED error.
79 */
80STATIC int /* error */
81xfs_inobt_update(
82 struct xfs_btree_cur *cur, /* btree cursor */
83 xfs_inobt_rec_incore_t *irec) /* btree record */
84{
85 union xfs_btree_rec rec;
86
87 rec.inobt.ir_startino = cpu_to_be32(irec->ir_startino);
88 rec.inobt.ir_freecount = cpu_to_be32(irec->ir_freecount);
89 rec.inobt.ir_free = cpu_to_be64(irec->ir_free);
90 return xfs_btree_update(cur, &rec);
91}
92
93/*
94 * Get the data from the pointed-to record.
95 */
96int /* error */
97xfs_inobt_get_rec(
98 struct xfs_btree_cur *cur, /* btree cursor */
99 xfs_inobt_rec_incore_t *irec, /* btree record */
100 int *stat) /* output: success/failure */
101{
102 union xfs_btree_rec *rec;
103 int error;
104
105 error = xfs_btree_get_rec(cur, &rec, stat);
106 if (!error && *stat == 1) {
107 irec->ir_startino = be32_to_cpu(rec->inobt.ir_startino);
108 irec->ir_freecount = be32_to_cpu(rec->inobt.ir_freecount);
109 irec->ir_free = be64_to_cpu(rec->inobt.ir_free);
110 }
111 return error;
112}
113
114/*
115 * Verify that the number of free inodes in the AGI is correct.
116 */
117#ifdef DEBUG
118STATIC int
119xfs_check_agi_freecount(
120 struct xfs_btree_cur *cur,
121 struct xfs_agi *agi)
122{
123 if (cur->bc_nlevels == 1) {
124 xfs_inobt_rec_incore_t rec;
125 int freecount = 0;
126 int error;
127 int i;
128
129 error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &i);
130 if (error)
131 return error;
132
133 do {
134 error = xfs_inobt_get_rec(cur, &rec, &i);
135 if (error)
136 return error;
137
138 if (i) {
139 freecount += rec.ir_freecount;
140 error = xfs_btree_increment(cur, 0, &i);
141 if (error)
142 return error;
143 }
144 } while (i == 1);
145
146 if (!XFS_FORCED_SHUTDOWN(cur->bc_mp))
147 ASSERT(freecount == be32_to_cpu(agi->agi_freecount));
148 }
149 return 0;
150}
151#else
152#define xfs_check_agi_freecount(cur, agi) 0
153#endif
154
155/*
156 * Initialise a new set of inodes. When called without a transaction context
157 * (e.g. from recovery) we initiate a delayed write of the inode buffers rather
158 * than logging them (which in a transaction context puts them into the AIL
159 * for writeback rather than the xfsbufd queue).
160 */
161int
162xfs_ialloc_inode_init(
163 struct xfs_mount *mp,
164 struct xfs_trans *tp,
165 struct list_head *buffer_list,
166 xfs_agnumber_t agno,
167 xfs_agblock_t agbno,
168 xfs_agblock_t length,
169 unsigned int gen)
170{
171 struct xfs_buf *fbuf;
172 struct xfs_dinode *free;
173 int nbufs, blks_per_cluster, inodes_per_cluster;
174 int version;
175 int i, j;
176 xfs_daddr_t d;
177 xfs_ino_t ino = 0;
178
179 /*
180 * Loop over the new block(s), filling in the inodes. For small block
181 * sizes, manipulate the inodes in buffers which are multiples of the
182 * blocks size.
183 */
184 blks_per_cluster = xfs_icluster_size_fsb(mp);
185 inodes_per_cluster = blks_per_cluster << mp->m_sb.sb_inopblog;
186 nbufs = length / blks_per_cluster;
187
188 /*
189 * Figure out what version number to use in the inodes we create. If
190 * the superblock version has caught up to the one that supports the new
191 * inode format, then use the new inode version. Otherwise use the old
192 * version so that old kernels will continue to be able to use the file
193 * system.
194 *
195 * For v3 inodes, we also need to write the inode number into the inode,
196 * so calculate the first inode number of the chunk here as
197 * XFS_OFFBNO_TO_AGINO() only works within a filesystem block, not
198 * across multiple filesystem blocks (such as a cluster) and so cannot
199 * be used in the cluster buffer loop below.
200 *
201 * Further, because we are writing the inode directly into the buffer
202 * and calculating a CRC on the entire inode, we have ot log the entire
203 * inode so that the entire range the CRC covers is present in the log.
204 * That means for v3 inode we log the entire buffer rather than just the
205 * inode cores.
206 */
207 if (xfs_sb_version_hascrc(&mp->m_sb)) {
208 version = 3;
209 ino = XFS_AGINO_TO_INO(mp, agno,
210 XFS_OFFBNO_TO_AGINO(mp, agbno, 0));
211
212 /*
213 * log the initialisation that is about to take place as an
214 * logical operation. This means the transaction does not
215 * need to log the physical changes to the inode buffers as log
216 * recovery will know what initialisation is actually needed.
217 * Hence we only need to log the buffers as "ordered" buffers so
218 * they track in the AIL as if they were physically logged.
219 */
220 if (tp)
221 xfs_icreate_log(tp, agno, agbno, mp->m_ialloc_inos,
222 mp->m_sb.sb_inodesize, length, gen);
223 } else if (xfs_sb_version_hasnlink(&mp->m_sb))
224 version = 2;
225 else
226 version = 1;
227
228 for (j = 0; j < nbufs; j++) {
229 /*
230 * Get the block.
231 */
232 d = XFS_AGB_TO_DADDR(mp, agno, agbno + (j * blks_per_cluster));
233 fbuf = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
234 mp->m_bsize * blks_per_cluster,
235 XBF_UNMAPPED);
236 if (!fbuf)
237 return ENOMEM;
238
239 /* Initialize the inode buffers and log them appropriately. */
240 fbuf->b_ops = &xfs_inode_buf_ops;
241 xfs_buf_zero(fbuf, 0, BBTOB(fbuf->b_length));
242 for (i = 0; i < inodes_per_cluster; i++) {
243 int ioffset = i << mp->m_sb.sb_inodelog;
244 uint isize = xfs_dinode_size(version);
245
246 free = xfs_make_iptr(mp, fbuf, i);
247 free->di_magic = cpu_to_be16(XFS_DINODE_MAGIC);
248 free->di_version = version;
249 free->di_gen = cpu_to_be32(gen);
250 free->di_next_unlinked = cpu_to_be32(NULLAGINO);
251
252 if (version == 3) {
253 free->di_ino = cpu_to_be64(ino);
254 ino++;
255 uuid_copy(&free->di_uuid, &mp->m_sb.sb_uuid);
256 xfs_dinode_calc_crc(mp, free);
257 } else if (tp) {
258 /* just log the inode core */
259 xfs_trans_log_buf(tp, fbuf, ioffset,
260 ioffset + isize - 1);
261 }
262 }
263
264 if (tp) {
265 /*
266 * Mark the buffer as an inode allocation buffer so it
267 * sticks in AIL at the point of this allocation
268 * transaction. This ensures the they are on disk before
269 * the tail of the log can be moved past this
270 * transaction (i.e. by preventing relogging from moving
271 * it forward in the log).
272 */
273 xfs_trans_inode_alloc_buf(tp, fbuf);
274 if (version == 3) {
275 /*
276 * Mark the buffer as ordered so that they are
277 * not physically logged in the transaction but
278 * still tracked in the AIL as part of the
279 * transaction and pin the log appropriately.
280 */
281 xfs_trans_ordered_buf(tp, fbuf);
282 xfs_trans_log_buf(tp, fbuf, 0,
283 BBTOB(fbuf->b_length) - 1);
284 }
285 } else {
286 fbuf->b_flags |= XBF_DONE;
287 xfs_buf_delwri_queue(fbuf, buffer_list);
288 xfs_buf_relse(fbuf);
289 }
290 }
291 return 0;
292}
293
294/*
295 * Allocate new inodes in the allocation group specified by agbp.
296 * Return 0 for success, else error code.
297 */
298STATIC int /* error code or 0 */
299xfs_ialloc_ag_alloc(
300 xfs_trans_t *tp, /* transaction pointer */
301 xfs_buf_t *agbp, /* alloc group buffer */
302 int *alloc)
303{
304 xfs_agi_t *agi; /* allocation group header */
305 xfs_alloc_arg_t args; /* allocation argument structure */
306 xfs_btree_cur_t *cur; /* inode btree cursor */
307 xfs_agnumber_t agno;
308 int error;
309 int i;
310 xfs_agino_t newino; /* new first inode's number */
311 xfs_agino_t newlen; /* new number of inodes */
312 xfs_agino_t thisino; /* current inode number, for loop */
313 int isaligned = 0; /* inode allocation at stripe unit */
314 /* boundary */
315 struct xfs_perag *pag;
316
317 memset(&args, 0, sizeof(args));
318 args.tp = tp;
319 args.mp = tp->t_mountp;
320
321 /*
322 * Locking will ensure that we don't have two callers in here
323 * at one time.
324 */
325 newlen = args.mp->m_ialloc_inos;
326 if (args.mp->m_maxicount &&
327 args.mp->m_sb.sb_icount + newlen > args.mp->m_maxicount)
328 return XFS_ERROR(ENOSPC);
329 args.minlen = args.maxlen = args.mp->m_ialloc_blks;
330 /*
331 * First try to allocate inodes contiguous with the last-allocated
332 * chunk of inodes. If the filesystem is striped, this will fill
333 * an entire stripe unit with inodes.
334 */
335 agi = XFS_BUF_TO_AGI(agbp);
336 newino = be32_to_cpu(agi->agi_newino);
337 agno = be32_to_cpu(agi->agi_seqno);
338 args.agbno = XFS_AGINO_TO_AGBNO(args.mp, newino) +
339 args.mp->m_ialloc_blks;
340 if (likely(newino != NULLAGINO &&
341 (args.agbno < be32_to_cpu(agi->agi_length)))) {
342 args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
343 args.type = XFS_ALLOCTYPE_THIS_BNO;
344 args.prod = 1;
345
346 /*
347 * We need to take into account alignment here to ensure that
348 * we don't modify the free list if we fail to have an exact
349 * block. If we don't have an exact match, and every oher
350 * attempt allocation attempt fails, we'll end up cancelling
351 * a dirty transaction and shutting down.
352 *
353 * For an exact allocation, alignment must be 1,
354 * however we need to take cluster alignment into account when
355 * fixing up the freelist. Use the minalignslop field to
356 * indicate that extra blocks might be required for alignment,
357 * but not to use them in the actual exact allocation.
358 */
359 args.alignment = 1;
360 args.minalignslop = xfs_ialloc_cluster_alignment(&args) - 1;
361
362 /* Allow space for the inode btree to split. */
363 args.minleft = args.mp->m_in_maxlevels - 1;
364 if ((error = xfs_alloc_vextent(&args)))
365 return error;
366
367 /*
368 * This request might have dirtied the transaction if the AG can
369 * satisfy the request, but the exact block was not available.
370 * If the allocation did fail, subsequent requests will relax
371 * the exact agbno requirement and increase the alignment
372 * instead. It is critical that the total size of the request
373 * (len + alignment + slop) does not increase from this point
374 * on, so reset minalignslop to ensure it is not included in
375 * subsequent requests.
376 */
377 args.minalignslop = 0;
378 } else
379 args.fsbno = NULLFSBLOCK;
380
381 if (unlikely(args.fsbno == NULLFSBLOCK)) {
382 /*
383 * Set the alignment for the allocation.
384 * If stripe alignment is turned on then align at stripe unit
385 * boundary.
386 * If the cluster size is smaller than a filesystem block
387 * then we're doing I/O for inodes in filesystem block size
388 * pieces, so don't need alignment anyway.
389 */
390 isaligned = 0;
391 if (args.mp->m_sinoalign) {
392 ASSERT(!(args.mp->m_flags & XFS_MOUNT_NOALIGN));
393 args.alignment = args.mp->m_dalign;
394 isaligned = 1;
395 } else
396 args.alignment = xfs_ialloc_cluster_alignment(&args);
397 /*
398 * Need to figure out where to allocate the inode blocks.
399 * Ideally they should be spaced out through the a.g.
400 * For now, just allocate blocks up front.
401 */
402 args.agbno = be32_to_cpu(agi->agi_root);
403 args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
404 /*
405 * Allocate a fixed-size extent of inodes.
406 */
407 args.type = XFS_ALLOCTYPE_NEAR_BNO;
408 args.prod = 1;
409 /*
410 * Allow space for the inode btree to split.
411 */
412 args.minleft = args.mp->m_in_maxlevels - 1;
413 if ((error = xfs_alloc_vextent(&args)))
414 return error;
415 }
416
417 /*
418 * If stripe alignment is turned on, then try again with cluster
419 * alignment.
420 */
421 if (isaligned && args.fsbno == NULLFSBLOCK) {
422 args.type = XFS_ALLOCTYPE_NEAR_BNO;
423 args.agbno = be32_to_cpu(agi->agi_root);
424 args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
425 args.alignment = xfs_ialloc_cluster_alignment(&args);
426 if ((error = xfs_alloc_vextent(&args)))
427 return error;
428 }
429
430 if (args.fsbno == NULLFSBLOCK) {
431 *alloc = 0;
432 return 0;
433 }
434 ASSERT(args.len == args.minlen);
435
436 /*
437 * Stamp and write the inode buffers.
438 *
439 * Seed the new inode cluster with a random generation number. This
440 * prevents short-term reuse of generation numbers if a chunk is
441 * freed and then immediately reallocated. We use random numbers
442 * rather than a linear progression to prevent the next generation
443 * number from being easily guessable.
444 */
445 error = xfs_ialloc_inode_init(args.mp, tp, NULL, agno, args.agbno,
446 args.len, prandom_u32());
447
448 if (error)
449 return error;
450 /*
451 * Convert the results.
452 */
453 newino = XFS_OFFBNO_TO_AGINO(args.mp, args.agbno, 0);
454 be32_add_cpu(&agi->agi_count, newlen);
455 be32_add_cpu(&agi->agi_freecount, newlen);
456 pag = xfs_perag_get(args.mp, agno);
457 pag->pagi_freecount += newlen;
458 xfs_perag_put(pag);
459 agi->agi_newino = cpu_to_be32(newino);
460
461 /*
462 * Insert records describing the new inode chunk into the btree.
463 */
464 cur = xfs_inobt_init_cursor(args.mp, tp, agbp, agno);
465 for (thisino = newino;
466 thisino < newino + newlen;
467 thisino += XFS_INODES_PER_CHUNK) {
468 cur->bc_rec.i.ir_startino = thisino;
469 cur->bc_rec.i.ir_freecount = XFS_INODES_PER_CHUNK;
470 cur->bc_rec.i.ir_free = XFS_INOBT_ALL_FREE;
471 error = xfs_btree_lookup(cur, XFS_LOOKUP_EQ, &i);
472 if (error) {
473 xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
474 return error;
475 }
476 ASSERT(i == 0);
477 error = xfs_btree_insert(cur, &i);
478 if (error) {
479 xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
480 return error;
481 }
482 ASSERT(i == 1);
483 }
484 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
485 /*
486 * Log allocation group header fields
487 */
488 xfs_ialloc_log_agi(tp, agbp,
489 XFS_AGI_COUNT | XFS_AGI_FREECOUNT | XFS_AGI_NEWINO);
490 /*
491 * Modify/log superblock values for inode count and inode free count.
492 */
493 xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, (long)newlen);
494 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, (long)newlen);
495 *alloc = 1;
496 return 0;
497}
498
499STATIC xfs_agnumber_t
500xfs_ialloc_next_ag(
501 xfs_mount_t *mp)
502{
503 xfs_agnumber_t agno;
504
505 spin_lock(&mp->m_agirotor_lock);
506 agno = mp->m_agirotor;
507 if (++mp->m_agirotor >= mp->m_maxagi)
508 mp->m_agirotor = 0;
509 spin_unlock(&mp->m_agirotor_lock);
510
511 return agno;
512}
513
514/*
515 * Select an allocation group to look for a free inode in, based on the parent
516 * inode and the mode. Return the allocation group buffer.
517 */
518STATIC xfs_agnumber_t
519xfs_ialloc_ag_select(
520 xfs_trans_t *tp, /* transaction pointer */
521 xfs_ino_t parent, /* parent directory inode number */
522 umode_t mode, /* bits set to indicate file type */
523 int okalloc) /* ok to allocate more space */
524{
525 xfs_agnumber_t agcount; /* number of ag's in the filesystem */
526 xfs_agnumber_t agno; /* current ag number */
527 int flags; /* alloc buffer locking flags */
528 xfs_extlen_t ineed; /* blocks needed for inode allocation */
529 xfs_extlen_t longest = 0; /* longest extent available */
530 xfs_mount_t *mp; /* mount point structure */
531 int needspace; /* file mode implies space allocated */
532 xfs_perag_t *pag; /* per allocation group data */
533 xfs_agnumber_t pagno; /* parent (starting) ag number */
534 int error;
535
536 /*
537 * Files of these types need at least one block if length > 0
538 * (and they won't fit in the inode, but that's hard to figure out).
539 */
540 needspace = S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode);
541 mp = tp->t_mountp;
542 agcount = mp->m_maxagi;
543 if (S_ISDIR(mode))
544 pagno = xfs_ialloc_next_ag(mp);
545 else {
546 pagno = XFS_INO_TO_AGNO(mp, parent);
547 if (pagno >= agcount)
548 pagno = 0;
549 }
550
551 ASSERT(pagno < agcount);
552
553 /*
554 * Loop through allocation groups, looking for one with a little
555 * free space in it. Note we don't look for free inodes, exactly.
556 * Instead, we include whether there is a need to allocate inodes
557 * to mean that blocks must be allocated for them,
558 * if none are currently free.
559 */
560 agno = pagno;
561 flags = XFS_ALLOC_FLAG_TRYLOCK;
562 for (;;) {
563 pag = xfs_perag_get(mp, agno);
564 if (!pag->pagi_inodeok) {
565 xfs_ialloc_next_ag(mp);
566 goto nextag;
567 }
568
569 if (!pag->pagi_init) {
570 error = xfs_ialloc_pagi_init(mp, tp, agno);
571 if (error)
572 goto nextag;
573 }
574
575 if (pag->pagi_freecount) {
576 xfs_perag_put(pag);
577 return agno;
578 }
579
580 if (!okalloc)
581 goto nextag;
582
583 if (!pag->pagf_init) {
584 error = xfs_alloc_pagf_init(mp, tp, agno, flags);
585 if (error)
586 goto nextag;
587 }
588
589 /*
590 * Is there enough free space for the file plus a block of
591 * inodes? (if we need to allocate some)?
592 */
593 ineed = mp->m_ialloc_blks;
594 longest = pag->pagf_longest;
595 if (!longest)
596 longest = pag->pagf_flcount > 0;
597
598 if (pag->pagf_freeblks >= needspace + ineed &&
599 longest >= ineed) {
600 xfs_perag_put(pag);
601 return agno;
602 }
603nextag:
604 xfs_perag_put(pag);
605 /*
606 * No point in iterating over the rest, if we're shutting
607 * down.
608 */
609 if (XFS_FORCED_SHUTDOWN(mp))
610 return NULLAGNUMBER;
611 agno++;
612 if (agno >= agcount)
613 agno = 0;
614 if (agno == pagno) {
615 if (flags == 0)
616 return NULLAGNUMBER;
617 flags = 0;
618 }
619 }
620}
621
622/*
623 * Try to retrieve the next record to the left/right from the current one.
624 */
625STATIC int
626xfs_ialloc_next_rec(
627 struct xfs_btree_cur *cur,
628 xfs_inobt_rec_incore_t *rec,
629 int *done,
630 int left)
631{
632 int error;
633 int i;
634
635 if (left)
636 error = xfs_btree_decrement(cur, 0, &i);
637 else
638 error = xfs_btree_increment(cur, 0, &i);
639
640 if (error)
641 return error;
642 *done = !i;
643 if (i) {
644 error = xfs_inobt_get_rec(cur, rec, &i);
645 if (error)
646 return error;
647 XFS_WANT_CORRUPTED_RETURN(i == 1);
648 }
649
650 return 0;
651}
652
653STATIC int
654xfs_ialloc_get_rec(
655 struct xfs_btree_cur *cur,
656 xfs_agino_t agino,
657 xfs_inobt_rec_incore_t *rec,
658 int *done)
659{
660 int error;
661 int i;
662
663 error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_EQ, &i);
664 if (error)
665 return error;
666 *done = !i;
667 if (i) {
668 error = xfs_inobt_get_rec(cur, rec, &i);
669 if (error)
670 return error;
671 XFS_WANT_CORRUPTED_RETURN(i == 1);
672 }
673
674 return 0;
675}
676
677/*
678 * Allocate an inode.
679 *
680 * The caller selected an AG for us, and made sure that free inodes are
681 * available.
682 */
683STATIC int
684xfs_dialloc_ag(
685 struct xfs_trans *tp,
686 struct xfs_buf *agbp,
687 xfs_ino_t parent,
688 xfs_ino_t *inop)
689{
690 struct xfs_mount *mp = tp->t_mountp;
691 struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);
692 xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno);
693 xfs_agnumber_t pagno = XFS_INO_TO_AGNO(mp, parent);
694 xfs_agino_t pagino = XFS_INO_TO_AGINO(mp, parent);
695 struct xfs_perag *pag;
696 struct xfs_btree_cur *cur, *tcur;
697 struct xfs_inobt_rec_incore rec, trec;
698 xfs_ino_t ino;
699 int error;
700 int offset;
701 int i, j;
702
703 pag = xfs_perag_get(mp, agno);
704
705 ASSERT(pag->pagi_init);
706 ASSERT(pag->pagi_inodeok);
707 ASSERT(pag->pagi_freecount > 0);
708
709 restart_pagno:
710 cur = xfs_inobt_init_cursor(mp, tp, agbp, agno);
711 /*
712 * If pagino is 0 (this is the root inode allocation) use newino.
713 * This must work because we've just allocated some.
714 */
715 if (!pagino)
716 pagino = be32_to_cpu(agi->agi_newino);
717
718 error = xfs_check_agi_freecount(cur, agi);
719 if (error)
720 goto error0;
721
722 /*
723 * If in the same AG as the parent, try to get near the parent.
724 */
725 if (pagno == agno) {
726 int doneleft; /* done, to the left */
727 int doneright; /* done, to the right */
728 int searchdistance = 10;
729
730 error = xfs_inobt_lookup(cur, pagino, XFS_LOOKUP_LE, &i);
731 if (error)
732 goto error0;
733 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
734
735 error = xfs_inobt_get_rec(cur, &rec, &j);
736 if (error)
737 goto error0;
738 XFS_WANT_CORRUPTED_GOTO(j == 1, error0);
739
740 if (rec.ir_freecount > 0) {
741 /*
742 * Found a free inode in the same chunk
743 * as the parent, done.
744 */
745 goto alloc_inode;
746 }
747
748
749 /*
750 * In the same AG as parent, but parent's chunk is full.
751 */
752
753 /* duplicate the cursor, search left & right simultaneously */
754 error = xfs_btree_dup_cursor(cur, &tcur);
755 if (error)
756 goto error0;
757
758 /*
759 * Skip to last blocks looked up if same parent inode.
760 */
761 if (pagino != NULLAGINO &&
762 pag->pagl_pagino == pagino &&
763 pag->pagl_leftrec != NULLAGINO &&
764 pag->pagl_rightrec != NULLAGINO) {
765 error = xfs_ialloc_get_rec(tcur, pag->pagl_leftrec,
766 &trec, &doneleft);
767 if (error)
768 goto error1;
769
770 error = xfs_ialloc_get_rec(cur, pag->pagl_rightrec,
771 &rec, &doneright);
772 if (error)
773 goto error1;
774 } else {
775 /* search left with tcur, back up 1 record */
776 error = xfs_ialloc_next_rec(tcur, &trec, &doneleft, 1);
777 if (error)
778 goto error1;
779
780 /* search right with cur, go forward 1 record. */
781 error = xfs_ialloc_next_rec(cur, &rec, &doneright, 0);
782 if (error)
783 goto error1;
784 }
785
786 /*
787 * Loop until we find an inode chunk with a free inode.
788 */
789 while (!doneleft || !doneright) {
790 int useleft; /* using left inode chunk this time */
791
792 if (!--searchdistance) {
793 /*
794 * Not in range - save last search
795 * location and allocate a new inode
796 */
797 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
798 pag->pagl_leftrec = trec.ir_startino;
799 pag->pagl_rightrec = rec.ir_startino;
800 pag->pagl_pagino = pagino;
801 goto newino;
802 }
803
804 /* figure out the closer block if both are valid. */
805 if (!doneleft && !doneright) {
806 useleft = pagino -
807 (trec.ir_startino + XFS_INODES_PER_CHUNK - 1) <
808 rec.ir_startino - pagino;
809 } else {
810 useleft = !doneleft;
811 }
812
813 /* free inodes to the left? */
814 if (useleft && trec.ir_freecount) {
815 rec = trec;
816 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
817 cur = tcur;
818
819 pag->pagl_leftrec = trec.ir_startino;
820 pag->pagl_rightrec = rec.ir_startino;
821 pag->pagl_pagino = pagino;
822 goto alloc_inode;
823 }
824
825 /* free inodes to the right? */
826 if (!useleft && rec.ir_freecount) {
827 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
828
829 pag->pagl_leftrec = trec.ir_startino;
830 pag->pagl_rightrec = rec.ir_startino;
831 pag->pagl_pagino = pagino;
832 goto alloc_inode;
833 }
834
835 /* get next record to check */
836 if (useleft) {
837 error = xfs_ialloc_next_rec(tcur, &trec,
838 &doneleft, 1);
839 } else {
840 error = xfs_ialloc_next_rec(cur, &rec,
841 &doneright, 0);
842 }
843 if (error)
844 goto error1;
845 }
846
847 /*
848 * We've reached the end of the btree. because
849 * we are only searching a small chunk of the
850 * btree each search, there is obviously free
851 * inodes closer to the parent inode than we
852 * are now. restart the search again.
853 */
854 pag->pagl_pagino = NULLAGINO;
855 pag->pagl_leftrec = NULLAGINO;
856 pag->pagl_rightrec = NULLAGINO;
857 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
858 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
859 goto restart_pagno;
860 }
861
862 /*
863 * In a different AG from the parent.
864 * See if the most recently allocated block has any free.
865 */
866newino:
867 if (agi->agi_newino != cpu_to_be32(NULLAGINO)) {
868 error = xfs_inobt_lookup(cur, be32_to_cpu(agi->agi_newino),
869 XFS_LOOKUP_EQ, &i);
870 if (error)
871 goto error0;
872
873 if (i == 1) {
874 error = xfs_inobt_get_rec(cur, &rec, &j);
875 if (error)
876 goto error0;
877
878 if (j == 1 && rec.ir_freecount > 0) {
879 /*
880 * The last chunk allocated in the group
881 * still has a free inode.
882 */
883 goto alloc_inode;
884 }
885 }
886 }
887
888 /*
889 * None left in the last group, search the whole AG
890 */
891 error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &i);
892 if (error)
893 goto error0;
894 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
895
896 for (;;) {
897 error = xfs_inobt_get_rec(cur, &rec, &i);
898 if (error)
899 goto error0;
900 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
901 if (rec.ir_freecount > 0)
902 break;
903 error = xfs_btree_increment(cur, 0, &i);
904 if (error)
905 goto error0;
906 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
907 }
908
909alloc_inode:
910 offset = xfs_lowbit64(rec.ir_free);
911 ASSERT(offset >= 0);
912 ASSERT(offset < XFS_INODES_PER_CHUNK);
913 ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) %
914 XFS_INODES_PER_CHUNK) == 0);
915 ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset);
916 rec.ir_free &= ~XFS_INOBT_MASK(offset);
917 rec.ir_freecount--;
918 error = xfs_inobt_update(cur, &rec);
919 if (error)
920 goto error0;
921 be32_add_cpu(&agi->agi_freecount, -1);
922 xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
923 pag->pagi_freecount--;
924
925 error = xfs_check_agi_freecount(cur, agi);
926 if (error)
927 goto error0;
928
929 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
930 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1);
931 xfs_perag_put(pag);
932 *inop = ino;
933 return 0;
934error1:
935 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
936error0:
937 xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
938 xfs_perag_put(pag);
939 return error;
940}
941
942/*
943 * Allocate an inode on disk.
944 *
945 * Mode is used to tell whether the new inode will need space, and whether it
946 * is a directory.
947 *
948 * This function is designed to be called twice if it has to do an allocation
949 * to make more free inodes. On the first call, *IO_agbp should be set to NULL.
950 * If an inode is available without having to performn an allocation, an inode
951 * number is returned. In this case, *IO_agbp is set to NULL. If an allocation
952 * needs to be done, xfs_dialloc returns the current AGI buffer in *IO_agbp.
953 * The caller should then commit the current transaction, allocate a
954 * new transaction, and call xfs_dialloc() again, passing in the previous value
955 * of *IO_agbp. IO_agbp should be held across the transactions. Since the AGI
956 * buffer is locked across the two calls, the second call is guaranteed to have
957 * a free inode available.
958 *
959 * Once we successfully pick an inode its number is returned and the on-disk
960 * data structures are updated. The inode itself is not read in, since doing so
961 * would break ordering constraints with xfs_reclaim.
962 */
963int
964xfs_dialloc(
965 struct xfs_trans *tp,
966 xfs_ino_t parent,
967 umode_t mode,
968 int okalloc,
969 struct xfs_buf **IO_agbp,
970 xfs_ino_t *inop)
971{
972 struct xfs_mount *mp = tp->t_mountp;
973 struct xfs_buf *agbp;
974 xfs_agnumber_t agno;
975 int error;
976 int ialloced;
977 int noroom = 0;
978 xfs_agnumber_t start_agno;
979 struct xfs_perag *pag;
980
981 if (*IO_agbp) {
982 /*
983 * If the caller passes in a pointer to the AGI buffer,
984 * continue where we left off before. In this case, we
985 * know that the allocation group has free inodes.
986 */
987 agbp = *IO_agbp;
988 goto out_alloc;
989 }
990
991 /*
992 * We do not have an agbp, so select an initial allocation
993 * group for inode allocation.
994 */
995 start_agno = xfs_ialloc_ag_select(tp, parent, mode, okalloc);
996 if (start_agno == NULLAGNUMBER) {
997 *inop = NULLFSINO;
998 return 0;
999 }
1000
1001 /*
1002 * If we have already hit the ceiling of inode blocks then clear
1003 * okalloc so we scan all available agi structures for a free
1004 * inode.
1005 */
1006 if (mp->m_maxicount &&
1007 mp->m_sb.sb_icount + mp->m_ialloc_inos > mp->m_maxicount) {
1008 noroom = 1;
1009 okalloc = 0;
1010 }
1011
1012 /*
1013 * Loop until we find an allocation group that either has free inodes
1014 * or in which we can allocate some inodes. Iterate through the
1015 * allocation groups upward, wrapping at the end.
1016 */
1017 agno = start_agno;
1018 for (;;) {
1019 pag = xfs_perag_get(mp, agno);
1020 if (!pag->pagi_inodeok) {
1021 xfs_ialloc_next_ag(mp);
1022 goto nextag;
1023 }
1024
1025 if (!pag->pagi_init) {
1026 error = xfs_ialloc_pagi_init(mp, tp, agno);
1027 if (error)
1028 goto out_error;
1029 }
1030
1031 /*
1032 * Do a first racy fast path check if this AG is usable.
1033 */
1034 if (!pag->pagi_freecount && !okalloc)
1035 goto nextag;
1036
1037 /*
1038 * Then read in the AGI buffer and recheck with the AGI buffer
1039 * lock held.
1040 */
1041 error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
1042 if (error)
1043 goto out_error;
1044
1045 if (pag->pagi_freecount) {
1046 xfs_perag_put(pag);
1047 goto out_alloc;
1048 }
1049
1050 if (!okalloc)
1051 goto nextag_relse_buffer;
1052
1053
1054 error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced);
1055 if (error) {
1056 xfs_trans_brelse(tp, agbp);
1057
1058 if (error != ENOSPC)
1059 goto out_error;
1060
1061 xfs_perag_put(pag);
1062 *inop = NULLFSINO;
1063 return 0;
1064 }
1065
1066 if (ialloced) {
1067 /*
1068 * We successfully allocated some inodes, return
1069 * the current context to the caller so that it
1070 * can commit the current transaction and call
1071 * us again where we left off.
1072 */
1073 ASSERT(pag->pagi_freecount > 0);
1074 xfs_perag_put(pag);
1075
1076 *IO_agbp = agbp;
1077 *inop = NULLFSINO;
1078 return 0;
1079 }
1080
1081nextag_relse_buffer:
1082 xfs_trans_brelse(tp, agbp);
1083nextag:
1084 xfs_perag_put(pag);
1085 if (++agno == mp->m_sb.sb_agcount)
1086 agno = 0;
1087 if (agno == start_agno) {
1088 *inop = NULLFSINO;
1089 return noroom ? ENOSPC : 0;
1090 }
1091 }
1092
1093out_alloc:
1094 *IO_agbp = NULL;
1095 return xfs_dialloc_ag(tp, agbp, parent, inop);
1096out_error:
1097 xfs_perag_put(pag);
1098 return XFS_ERROR(error);
1099}
1100
1101/*
1102 * Free disk inode. Carefully avoids touching the incore inode, all
1103 * manipulations incore are the caller's responsibility.
1104 * The on-disk inode is not changed by this operation, only the
1105 * btree (free inode mask) is changed.
1106 */
1107int
1108xfs_difree(
1109 xfs_trans_t *tp, /* transaction pointer */
1110 xfs_ino_t inode, /* inode to be freed */
1111 xfs_bmap_free_t *flist, /* extents to free */
1112 int *delete, /* set if inode cluster was deleted */
1113 xfs_ino_t *first_ino) /* first inode in deleted cluster */
1114{
1115 /* REFERENCED */
1116 xfs_agblock_t agbno; /* block number containing inode */
1117 xfs_buf_t *agbp; /* buffer containing allocation group header */
1118 xfs_agino_t agino; /* inode number relative to allocation group */
1119 xfs_agnumber_t agno; /* allocation group number */
1120 xfs_agi_t *agi; /* allocation group header */
1121 xfs_btree_cur_t *cur; /* inode btree cursor */
1122 int error; /* error return value */
1123 int i; /* result code */
1124 int ilen; /* inodes in an inode cluster */
1125 xfs_mount_t *mp; /* mount structure for filesystem */
1126 int off; /* offset of inode in inode chunk */
1127 xfs_inobt_rec_incore_t rec; /* btree record */
1128 struct xfs_perag *pag;
1129
1130 mp = tp->t_mountp;
1131
1132 /*
1133 * Break up inode number into its components.
1134 */
1135 agno = XFS_INO_TO_AGNO(mp, inode);
1136 if (agno >= mp->m_sb.sb_agcount) {
1137 xfs_warn(mp, "%s: agno >= mp->m_sb.sb_agcount (%d >= %d).",
1138 __func__, agno, mp->m_sb.sb_agcount);
1139 ASSERT(0);
1140 return XFS_ERROR(EINVAL);
1141 }
1142 agino = XFS_INO_TO_AGINO(mp, inode);
1143 if (inode != XFS_AGINO_TO_INO(mp, agno, agino)) {
1144 xfs_warn(mp, "%s: inode != XFS_AGINO_TO_INO() (%llu != %llu).",
1145 __func__, (unsigned long long)inode,
1146 (unsigned long long)XFS_AGINO_TO_INO(mp, agno, agino));
1147 ASSERT(0);
1148 return XFS_ERROR(EINVAL);
1149 }
1150 agbno = XFS_AGINO_TO_AGBNO(mp, agino);
1151 if (agbno >= mp->m_sb.sb_agblocks) {
1152 xfs_warn(mp, "%s: agbno >= mp->m_sb.sb_agblocks (%d >= %d).",
1153 __func__, agbno, mp->m_sb.sb_agblocks);
1154 ASSERT(0);
1155 return XFS_ERROR(EINVAL);
1156 }
1157 /*
1158 * Get the allocation group header.
1159 */
1160 error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
1161 if (error) {
1162 xfs_warn(mp, "%s: xfs_ialloc_read_agi() returned error %d.",
1163 __func__, error);
1164 return error;
1165 }
1166 agi = XFS_BUF_TO_AGI(agbp);
1167 ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC));
1168 ASSERT(agbno < be32_to_cpu(agi->agi_length));
1169 /*
1170 * Initialize the cursor.
1171 */
1172 cur = xfs_inobt_init_cursor(mp, tp, agbp, agno);
1173
1174 error = xfs_check_agi_freecount(cur, agi);
1175 if (error)
1176 goto error0;
1177
1178 /*
1179 * Look for the entry describing this inode.
1180 */
1181 if ((error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE, &i))) {
1182 xfs_warn(mp, "%s: xfs_inobt_lookup() returned error %d.",
1183 __func__, error);
1184 goto error0;
1185 }
1186 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1187 error = xfs_inobt_get_rec(cur, &rec, &i);
1188 if (error) {
1189 xfs_warn(mp, "%s: xfs_inobt_get_rec() returned error %d.",
1190 __func__, error);
1191 goto error0;
1192 }
1193 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1194 /*
1195 * Get the offset in the inode chunk.
1196 */
1197 off = agino - rec.ir_startino;
1198 ASSERT(off >= 0 && off < XFS_INODES_PER_CHUNK);
1199 ASSERT(!(rec.ir_free & XFS_INOBT_MASK(off)));
1200 /*
1201 * Mark the inode free & increment the count.
1202 */
1203 rec.ir_free |= XFS_INOBT_MASK(off);
1204 rec.ir_freecount++;
1205
1206 /*
1207 * When an inode cluster is free, it becomes eligible for removal
1208 */
1209 if (!(mp->m_flags & XFS_MOUNT_IKEEP) &&
1210 (rec.ir_freecount == mp->m_ialloc_inos)) {
1211
1212 *delete = 1;
1213 *first_ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino);
1214
1215 /*
1216 * Remove the inode cluster from the AGI B+Tree, adjust the
1217 * AGI and Superblock inode counts, and mark the disk space
1218 * to be freed when the transaction is committed.
1219 */
1220 ilen = mp->m_ialloc_inos;
1221 be32_add_cpu(&agi->agi_count, -ilen);
1222 be32_add_cpu(&agi->agi_freecount, -(ilen - 1));
1223 xfs_ialloc_log_agi(tp, agbp, XFS_AGI_COUNT | XFS_AGI_FREECOUNT);
1224 pag = xfs_perag_get(mp, agno);
1225 pag->pagi_freecount -= ilen - 1;
1226 xfs_perag_put(pag);
1227 xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, -ilen);
1228 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -(ilen - 1));
1229
1230 if ((error = xfs_btree_delete(cur, &i))) {
1231 xfs_warn(mp, "%s: xfs_btree_delete returned error %d.",
1232 __func__, error);
1233 goto error0;
1234 }
1235
1236 xfs_bmap_add_free(XFS_AGB_TO_FSB(mp, agno,
1237 XFS_AGINO_TO_AGBNO(mp, rec.ir_startino)),
1238 mp->m_ialloc_blks, flist, mp);
1239 } else {
1240 *delete = 0;
1241
1242 error = xfs_inobt_update(cur, &rec);
1243 if (error) {
1244 xfs_warn(mp, "%s: xfs_inobt_update returned error %d.",
1245 __func__, error);
1246 goto error0;
1247 }
1248
1249 /*
1250 * Change the inode free counts and log the ag/sb changes.
1251 */
1252 be32_add_cpu(&agi->agi_freecount, 1);
1253 xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
1254 pag = xfs_perag_get(mp, agno);
1255 pag->pagi_freecount++;
1256 xfs_perag_put(pag);
1257 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, 1);
1258 }
1259
1260 error = xfs_check_agi_freecount(cur, agi);
1261 if (error)
1262 goto error0;
1263
1264 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
1265 return 0;
1266
1267error0:
1268 xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
1269 return error;
1270}
1271
1272STATIC int
1273xfs_imap_lookup(
1274 struct xfs_mount *mp,
1275 struct xfs_trans *tp,
1276 xfs_agnumber_t agno,
1277 xfs_agino_t agino,
1278 xfs_agblock_t agbno,
1279 xfs_agblock_t *chunk_agbno,
1280 xfs_agblock_t *offset_agbno,
1281 int flags)
1282{
1283 struct xfs_inobt_rec_incore rec;
1284 struct xfs_btree_cur *cur;
1285 struct xfs_buf *agbp;
1286 int error;
1287 int i;
1288
1289 error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
1290 if (error) {
1291 xfs_alert(mp,
1292 "%s: xfs_ialloc_read_agi() returned error %d, agno %d",
1293 __func__, error, agno);
1294 return error;
1295 }
1296
1297 /*
1298 * Lookup the inode record for the given agino. If the record cannot be
1299 * found, then it's an invalid inode number and we should abort. Once
1300 * we have a record, we need to ensure it contains the inode number
1301 * we are looking up.
1302 */
1303 cur = xfs_inobt_init_cursor(mp, tp, agbp, agno);
1304 error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE, &i);
1305 if (!error) {
1306 if (i)
1307 error = xfs_inobt_get_rec(cur, &rec, &i);
1308 if (!error && i == 0)
1309 error = EINVAL;
1310 }
1311
1312 xfs_trans_brelse(tp, agbp);
1313 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
1314 if (error)
1315 return error;
1316
1317 /* check that the returned record contains the required inode */
1318 if (rec.ir_startino > agino ||
1319 rec.ir_startino + mp->m_ialloc_inos <= agino)
1320 return EINVAL;
1321
1322 /* for untrusted inodes check it is allocated first */
1323 if ((flags & XFS_IGET_UNTRUSTED) &&
1324 (rec.ir_free & XFS_INOBT_MASK(agino - rec.ir_startino)))
1325 return EINVAL;
1326
1327 *chunk_agbno = XFS_AGINO_TO_AGBNO(mp, rec.ir_startino);
1328 *offset_agbno = agbno - *chunk_agbno;
1329 return 0;
1330}
1331
1332/*
1333 * Return the location of the inode in imap, for mapping it into a buffer.
1334 */
1335int
1336xfs_imap(
1337 xfs_mount_t *mp, /* file system mount structure */
1338 xfs_trans_t *tp, /* transaction pointer */
1339 xfs_ino_t ino, /* inode to locate */
1340 struct xfs_imap *imap, /* location map structure */
1341 uint flags) /* flags for inode btree lookup */
1342{
1343 xfs_agblock_t agbno; /* block number of inode in the alloc group */
1344 xfs_agino_t agino; /* inode number within alloc group */
1345 xfs_agnumber_t agno; /* allocation group number */
1346 int blks_per_cluster; /* num blocks per inode cluster */
1347 xfs_agblock_t chunk_agbno; /* first block in inode chunk */
1348 xfs_agblock_t cluster_agbno; /* first block in inode cluster */
1349 int error; /* error code */
1350 int offset; /* index of inode in its buffer */
1351 xfs_agblock_t offset_agbno; /* blks from chunk start to inode */
1352
1353 ASSERT(ino != NULLFSINO);
1354
1355 /*
1356 * Split up the inode number into its parts.
1357 */
1358 agno = XFS_INO_TO_AGNO(mp, ino);
1359 agino = XFS_INO_TO_AGINO(mp, ino);
1360 agbno = XFS_AGINO_TO_AGBNO(mp, agino);
1361 if (agno >= mp->m_sb.sb_agcount || agbno >= mp->m_sb.sb_agblocks ||
1362 ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
1363#ifdef DEBUG
1364 /*
1365 * Don't output diagnostic information for untrusted inodes
1366 * as they can be invalid without implying corruption.
1367 */
1368 if (flags & XFS_IGET_UNTRUSTED)
1369 return XFS_ERROR(EINVAL);
1370 if (agno >= mp->m_sb.sb_agcount) {
1371 xfs_alert(mp,
1372 "%s: agno (%d) >= mp->m_sb.sb_agcount (%d)",
1373 __func__, agno, mp->m_sb.sb_agcount);
1374 }
1375 if (agbno >= mp->m_sb.sb_agblocks) {
1376 xfs_alert(mp,
1377 "%s: agbno (0x%llx) >= mp->m_sb.sb_agblocks (0x%lx)",
1378 __func__, (unsigned long long)agbno,
1379 (unsigned long)mp->m_sb.sb_agblocks);
1380 }
1381 if (ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
1382 xfs_alert(mp,
1383 "%s: ino (0x%llx) != XFS_AGINO_TO_INO() (0x%llx)",
1384 __func__, ino,
1385 XFS_AGINO_TO_INO(mp, agno, agino));
1386 }
1387 xfs_stack_trace();
1388#endif /* DEBUG */
1389 return XFS_ERROR(EINVAL);
1390 }
1391
1392 blks_per_cluster = xfs_icluster_size_fsb(mp);
1393
1394 /*
1395 * For bulkstat and handle lookups, we have an untrusted inode number
1396 * that we have to verify is valid. We cannot do this just by reading
1397 * the inode buffer as it may have been unlinked and removed leaving
1398 * inodes in stale state on disk. Hence we have to do a btree lookup
1399 * in all cases where an untrusted inode number is passed.
1400 */
1401 if (flags & XFS_IGET_UNTRUSTED) {
1402 error = xfs_imap_lookup(mp, tp, agno, agino, agbno,
1403 &chunk_agbno, &offset_agbno, flags);
1404 if (error)
1405 return error;
1406 goto out_map;
1407 }
1408
1409 /*
1410 * If the inode cluster size is the same as the blocksize or
1411 * smaller we get to the buffer by simple arithmetics.
1412 */
1413 if (blks_per_cluster == 1) {
1414 offset = XFS_INO_TO_OFFSET(mp, ino);
1415 ASSERT(offset < mp->m_sb.sb_inopblock);
1416
1417 imap->im_blkno = XFS_AGB_TO_DADDR(mp, agno, agbno);
1418 imap->im_len = XFS_FSB_TO_BB(mp, 1);
1419 imap->im_boffset = (ushort)(offset << mp->m_sb.sb_inodelog);
1420 return 0;
1421 }
1422
1423 /*
1424 * If the inode chunks are aligned then use simple maths to
1425 * find the location. Otherwise we have to do a btree
1426 * lookup to find the location.
1427 */
1428 if (mp->m_inoalign_mask) {
1429 offset_agbno = agbno & mp->m_inoalign_mask;
1430 chunk_agbno = agbno - offset_agbno;
1431 } else {
1432 error = xfs_imap_lookup(mp, tp, agno, agino, agbno,
1433 &chunk_agbno, &offset_agbno, flags);
1434 if (error)
1435 return error;
1436 }
1437
1438out_map:
1439 ASSERT(agbno >= chunk_agbno);
1440 cluster_agbno = chunk_agbno +
1441 ((offset_agbno / blks_per_cluster) * blks_per_cluster);
1442 offset = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
1443 XFS_INO_TO_OFFSET(mp, ino);
1444
1445 imap->im_blkno = XFS_AGB_TO_DADDR(mp, agno, cluster_agbno);
1446 imap->im_len = XFS_FSB_TO_BB(mp, blks_per_cluster);
1447 imap->im_boffset = (ushort)(offset << mp->m_sb.sb_inodelog);
1448
1449 /*
1450 * If the inode number maps to a block outside the bounds
1451 * of the file system then return NULL rather than calling
1452 * read_buf and panicing when we get an error from the
1453 * driver.
1454 */
1455 if ((imap->im_blkno + imap->im_len) >
1456 XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)) {
1457 xfs_alert(mp,
1458 "%s: (im_blkno (0x%llx) + im_len (0x%llx)) > sb_dblocks (0x%llx)",
1459 __func__, (unsigned long long) imap->im_blkno,
1460 (unsigned long long) imap->im_len,
1461 XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks));
1462 return XFS_ERROR(EINVAL);
1463 }
1464 return 0;
1465}
1466
1467/*
1468 * Compute and fill in value of m_in_maxlevels.
1469 */
1470void
1471xfs_ialloc_compute_maxlevels(
1472 xfs_mount_t *mp) /* file system mount structure */
1473{
1474 int level;
1475 uint maxblocks;
1476 uint maxleafents;
1477 int minleafrecs;
1478 int minnoderecs;
1479
1480 maxleafents = (1LL << XFS_INO_AGINO_BITS(mp)) >>
1481 XFS_INODES_PER_CHUNK_LOG;
1482 minleafrecs = mp->m_alloc_mnr[0];
1483 minnoderecs = mp->m_alloc_mnr[1];
1484 maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1485 for (level = 1; maxblocks > 1; level++)
1486 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1487 mp->m_in_maxlevels = level;
1488}
1489
1490/*
1491 * Log specified fields for the ag hdr (inode section)
1492 */
1493void
1494xfs_ialloc_log_agi(
1495 xfs_trans_t *tp, /* transaction pointer */
1496 xfs_buf_t *bp, /* allocation group header buffer */
1497 int fields) /* bitmask of fields to log */
1498{
1499 int first; /* first byte number */
1500 int last; /* last byte number */
1501 static const short offsets[] = { /* field starting offsets */
1502 /* keep in sync with bit definitions */
1503 offsetof(xfs_agi_t, agi_magicnum),
1504 offsetof(xfs_agi_t, agi_versionnum),
1505 offsetof(xfs_agi_t, agi_seqno),
1506 offsetof(xfs_agi_t, agi_length),
1507 offsetof(xfs_agi_t, agi_count),
1508 offsetof(xfs_agi_t, agi_root),
1509 offsetof(xfs_agi_t, agi_level),
1510 offsetof(xfs_agi_t, agi_freecount),
1511 offsetof(xfs_agi_t, agi_newino),
1512 offsetof(xfs_agi_t, agi_dirino),
1513 offsetof(xfs_agi_t, agi_unlinked),
1514 sizeof(xfs_agi_t)
1515 };
1516#ifdef DEBUG
1517 xfs_agi_t *agi; /* allocation group header */
1518
1519 agi = XFS_BUF_TO_AGI(bp);
1520 ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC));
1521#endif
1522 /*
1523 * Compute byte offsets for the first and last fields.
1524 */
1525 xfs_btree_offsets(fields, offsets, XFS_AGI_NUM_BITS, &first, &last);
1526 /*
1527 * Log the allocation group inode header buffer.
1528 */
1529 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGI_BUF);
1530 xfs_trans_log_buf(tp, bp, first, last);
1531}
1532
1533#ifdef DEBUG
1534STATIC void
1535xfs_check_agi_unlinked(
1536 struct xfs_agi *agi)
1537{
1538 int i;
1539
1540 for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
1541 ASSERT(agi->agi_unlinked[i]);
1542}
1543#else
1544#define xfs_check_agi_unlinked(agi)
1545#endif
1546
1547static bool
1548xfs_agi_verify(
1549 struct xfs_buf *bp)
1550{
1551 struct xfs_mount *mp = bp->b_target->bt_mount;
1552 struct xfs_agi *agi = XFS_BUF_TO_AGI(bp);
1553
1554 if (xfs_sb_version_hascrc(&mp->m_sb) &&
1555 !uuid_equal(&agi->agi_uuid, &mp->m_sb.sb_uuid))
1556 return false;
1557 /*
1558 * Validate the magic number of the agi block.
1559 */
1560 if (agi->agi_magicnum != cpu_to_be32(XFS_AGI_MAGIC))
1561 return false;
1562 if (!XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum)))
1563 return false;
1564
1565 /*
1566 * during growfs operations, the perag is not fully initialised,
1567 * so we can't use it for any useful checking. growfs ensures we can't
1568 * use it by using uncached buffers that don't have the perag attached
1569 * so we can detect and avoid this problem.
1570 */
1571 if (bp->b_pag && be32_to_cpu(agi->agi_seqno) != bp->b_pag->pag_agno)
1572 return false;
1573
1574 xfs_check_agi_unlinked(agi);
1575 return true;
1576}
1577
1578static void
1579xfs_agi_read_verify(
1580 struct xfs_buf *bp)
1581{
1582 struct xfs_mount *mp = bp->b_target->bt_mount;
1583
1584 if (xfs_sb_version_hascrc(&mp->m_sb) &&
1585 !xfs_buf_verify_cksum(bp, XFS_AGI_CRC_OFF))
1586 xfs_buf_ioerror(bp, EFSBADCRC);
1587 else if (XFS_TEST_ERROR(!xfs_agi_verify(bp), mp,
1588 XFS_ERRTAG_IALLOC_READ_AGI,
1589 XFS_RANDOM_IALLOC_READ_AGI))
1590 xfs_buf_ioerror(bp, EFSCORRUPTED);
1591
1592 if (bp->b_error)
1593 xfs_verifier_error(bp);
1594}
1595
1596static void
1597xfs_agi_write_verify(
1598 struct xfs_buf *bp)
1599{
1600 struct xfs_mount *mp = bp->b_target->bt_mount;
1601 struct xfs_buf_log_item *bip = bp->b_fspriv;
1602
1603 if (!xfs_agi_verify(bp)) {
1604 xfs_buf_ioerror(bp, EFSCORRUPTED);
1605 xfs_verifier_error(bp);
1606 return;
1607 }
1608
1609 if (!xfs_sb_version_hascrc(&mp->m_sb))
1610 return;
1611
1612 if (bip)
1613 XFS_BUF_TO_AGI(bp)->agi_lsn = cpu_to_be64(bip->bli_item.li_lsn);
1614 xfs_buf_update_cksum(bp, XFS_AGI_CRC_OFF);
1615}
1616
1617const struct xfs_buf_ops xfs_agi_buf_ops = {
1618 .verify_read = xfs_agi_read_verify,
1619 .verify_write = xfs_agi_write_verify,
1620};
1621
1622/*
1623 * Read in the allocation group header (inode allocation section)
1624 */
1625int
1626xfs_read_agi(
1627 struct xfs_mount *mp, /* file system mount structure */
1628 struct xfs_trans *tp, /* transaction pointer */
1629 xfs_agnumber_t agno, /* allocation group number */
1630 struct xfs_buf **bpp) /* allocation group hdr buf */
1631{
1632 int error;
1633
1634 trace_xfs_read_agi(mp, agno);
1635
1636 ASSERT(agno != NULLAGNUMBER);
1637 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
1638 XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
1639 XFS_FSS_TO_BB(mp, 1), 0, bpp, &xfs_agi_buf_ops);
1640 if (error)
1641 return error;
1642
1643 ASSERT(!xfs_buf_geterror(*bpp));
1644 xfs_buf_set_ref(*bpp, XFS_AGI_REF);
1645 return 0;
1646}
1647
1648int
1649xfs_ialloc_read_agi(
1650 struct xfs_mount *mp, /* file system mount structure */
1651 struct xfs_trans *tp, /* transaction pointer */
1652 xfs_agnumber_t agno, /* allocation group number */
1653 struct xfs_buf **bpp) /* allocation group hdr buf */
1654{
1655 struct xfs_agi *agi; /* allocation group header */
1656 struct xfs_perag *pag; /* per allocation group data */
1657 int error;
1658
1659 trace_xfs_ialloc_read_agi(mp, agno);
1660
1661 error = xfs_read_agi(mp, tp, agno, bpp);
1662 if (error)
1663 return error;
1664
1665 agi = XFS_BUF_TO_AGI(*bpp);
1666 pag = xfs_perag_get(mp, agno);
1667 if (!pag->pagi_init) {
1668 pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);
1669 pag->pagi_count = be32_to_cpu(agi->agi_count);
1670 pag->pagi_init = 1;
1671 }
1672
1673 /*
1674 * It's possible for these to be out of sync if
1675 * we are in the middle of a forced shutdown.
1676 */
1677 ASSERT(pag->pagi_freecount == be32_to_cpu(agi->agi_freecount) ||
1678 XFS_FORCED_SHUTDOWN(mp));
1679 xfs_perag_put(pag);
1680 return 0;
1681}
1682
1683/*
1684 * Read in the agi to initialise the per-ag data in the mount structure
1685 */
1686int
1687xfs_ialloc_pagi_init(
1688 xfs_mount_t *mp, /* file system mount structure */
1689 xfs_trans_t *tp, /* transaction pointer */
1690 xfs_agnumber_t agno) /* allocation group number */
1691{
1692 xfs_buf_t *bp = NULL;
1693 int error;
1694
1695 error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
1696 if (error)
1697 return error;
1698 if (bp)
1699 xfs_trans_brelse(tp, bp);
1700 return 0;
1701}