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xfs: simplify validation of the unwritten extent bit
[linux-2.6-block.git] / fs / xfs / xfs_fsmap.c
CommitLineData
e89c0413
DW		 1/*
2 * Copyright (C) 2017 Oracle. All Rights Reserved.
3 *
4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it would be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
19 */
20#include "xfs.h"
21#include "xfs_fs.h"
22#include "xfs_shared.h"
23#include "xfs_format.h"
24#include "xfs_log_format.h"
25#include "xfs_trans_resv.h"
26#include "xfs_sb.h"
27#include "xfs_mount.h"
28#include "xfs_defer.h"
29#include "xfs_inode.h"
30#include "xfs_trans.h"
31#include "xfs_error.h"
32#include "xfs_btree.h"
33#include "xfs_rmap_btree.h"
34#include "xfs_trace.h"
35#include "xfs_log.h"
36#include "xfs_rmap.h"
37#include "xfs_alloc.h"
38#include "xfs_bit.h"
39#include <linux/fsmap.h>
40#include "xfs_fsmap.h"
41#include "xfs_refcount.h"
42#include "xfs_refcount_btree.h"
a1cae728 43#include "xfs_alloc_btree.h"
4c934c7d 44#include "xfs_rtalloc.h"
e89c0413
DW		 45
46/* Convert an xfs_fsmap to an fsmap. */
47void
48xfs_fsmap_from_internal(
49 struct fsmap *dest,
50 struct xfs_fsmap *src)
51{
52 dest->fmr_device = src->fmr_device;
53 dest->fmr_flags = src->fmr_flags;
54 dest->fmr_physical = BBTOB(src->fmr_physical);
55 dest->fmr_owner = src->fmr_owner;
56 dest->fmr_offset = BBTOB(src->fmr_offset);
57 dest->fmr_length = BBTOB(src->fmr_length);
58 dest->fmr_reserved[0] = 0;
59 dest->fmr_reserved[1] = 0;
60 dest->fmr_reserved[2] = 0;
61}
62
63/* Convert an fsmap to an xfs_fsmap. */
64void
65xfs_fsmap_to_internal(
66 struct xfs_fsmap *dest,
67 struct fsmap *src)
68{
69 dest->fmr_device = src->fmr_device;
70 dest->fmr_flags = src->fmr_flags;
71 dest->fmr_physical = BTOBBT(src->fmr_physical);
72 dest->fmr_owner = src->fmr_owner;
73 dest->fmr_offset = BTOBBT(src->fmr_offset);
74 dest->fmr_length = BTOBBT(src->fmr_length);
75}
76
77/* Convert an fsmap owner into an rmapbt owner. */
78static int
79xfs_fsmap_owner_to_rmap(
80 struct xfs_rmap_irec *dest,
81 struct xfs_fsmap *src)
82{
83 if (!(src->fmr_flags & FMR_OF_SPECIAL_OWNER)) {
84 dest->rm_owner = src->fmr_owner;
85 return 0;
86 }
87
88 switch (src->fmr_owner) {
89 case 0: /* "lowest owner id possible" */
90 case -1ULL: /* "highest owner id possible" */
91 dest->rm_owner = 0;
92 break;
93 case XFS_FMR_OWN_FREE:
94 dest->rm_owner = XFS_RMAP_OWN_NULL;
95 break;
96 case XFS_FMR_OWN_UNKNOWN:
97 dest->rm_owner = XFS_RMAP_OWN_UNKNOWN;
98 break;
99 case XFS_FMR_OWN_FS:
100 dest->rm_owner = XFS_RMAP_OWN_FS;
101 break;
102 case XFS_FMR_OWN_LOG:
103 dest->rm_owner = XFS_RMAP_OWN_LOG;
104 break;
105 case XFS_FMR_OWN_AG:
106 dest->rm_owner = XFS_RMAP_OWN_AG;
107 break;
108 case XFS_FMR_OWN_INOBT:
109 dest->rm_owner = XFS_RMAP_OWN_INOBT;
110 break;
111 case XFS_FMR_OWN_INODES:
112 dest->rm_owner = XFS_RMAP_OWN_INODES;
113 break;
114 case XFS_FMR_OWN_REFC:
115 dest->rm_owner = XFS_RMAP_OWN_REFC;
116 break;
117 case XFS_FMR_OWN_COW:
118 dest->rm_owner = XFS_RMAP_OWN_COW;
119 break;
120 case XFS_FMR_OWN_DEFECTIVE: /* not implemented */
121 /* fall through */
122 default:
123 return -EINVAL;
124 }
125 return 0;
126}
127
128/* Convert an rmapbt owner into an fsmap owner. */
129static int
130xfs_fsmap_owner_from_rmap(
131 struct xfs_fsmap *dest,
132 struct xfs_rmap_irec *src)
133{
134 dest->fmr_flags = 0;
135 if (!XFS_RMAP_NON_INODE_OWNER(src->rm_owner)) {
136 dest->fmr_owner = src->rm_owner;
137 return 0;
138 }
139 dest->fmr_flags |= FMR_OF_SPECIAL_OWNER;
140
141 switch (src->rm_owner) {
142 case XFS_RMAP_OWN_FS:
143 dest->fmr_owner = XFS_FMR_OWN_FS;
144 break;
145 case XFS_RMAP_OWN_LOG:
146 dest->fmr_owner = XFS_FMR_OWN_LOG;
147 break;
148 case XFS_RMAP_OWN_AG:
149 dest->fmr_owner = XFS_FMR_OWN_AG;
150 break;
151 case XFS_RMAP_OWN_INOBT:
152 dest->fmr_owner = XFS_FMR_OWN_INOBT;
153 break;
154 case XFS_RMAP_OWN_INODES:
155 dest->fmr_owner = XFS_FMR_OWN_INODES;
156 break;
157 case XFS_RMAP_OWN_REFC:
158 dest->fmr_owner = XFS_FMR_OWN_REFC;
159 break;
160 case XFS_RMAP_OWN_COW:
161 dest->fmr_owner = XFS_FMR_OWN_COW;
162 break;
a1cae728
DW		 163 case XFS_RMAP_OWN_NULL: /* "free" */
164 dest->fmr_owner = XFS_FMR_OWN_FREE;
165 break;
e89c0413
DW		 166 default:
167 return -EFSCORRUPTED;
168 }
169 return 0;
170}
171
172/* getfsmap query state */
173struct xfs_getfsmap_info {
174 struct xfs_fsmap_head *head;
175 xfs_fsmap_format_t formatter; /* formatting fn */
176 void *format_arg; /* format buffer */
177 struct xfs_buf *agf_bp; /* AGF, for refcount queries */
178 xfs_daddr_t next_daddr; /* next daddr we expect */
179 u64 missing_owner; /* owner of holes */
180 u32 dev; /* device id */
181 xfs_agnumber_t agno; /* AG number, if applicable */
182 struct xfs_rmap_irec low; /* low rmap key */
183 struct xfs_rmap_irec high; /* high rmap key */
184 bool last; /* last extent? */
185};
186
187/* Associate a device with a getfsmap handler. */
188struct xfs_getfsmap_dev {
189 u32 dev;
190 int (*fn)(struct xfs_trans *tp,
191 struct xfs_fsmap *keys,
192 struct xfs_getfsmap_info *info);
193};
194
195/* Compare two getfsmap device handlers. */
196static int
197xfs_getfsmap_dev_compare(
198 const void *p1,
199 const void *p2)
200{
201 const struct xfs_getfsmap_dev *d1 = p1;
202 const struct xfs_getfsmap_dev *d2 = p2;
203
204 return d1->dev - d2->dev;
205}
206
207/* Decide if this mapping is shared. */
208STATIC int
209xfs_getfsmap_is_shared(
210 struct xfs_trans *tp,
211 struct xfs_getfsmap_info *info,
212 struct xfs_rmap_irec *rec,
213 bool *stat)
214{
215 struct xfs_mount *mp = tp->t_mountp;
216 struct xfs_btree_cur *cur;
217 xfs_agblock_t fbno;
218 xfs_extlen_t flen;
219 int error;
220
221 *stat = false;
222 if (!xfs_sb_version_hasreflink(&mp->m_sb))
223 return 0;
224 /* rt files will have agno set to NULLAGNUMBER */
225 if (info->agno == NULLAGNUMBER)
226 return 0;
227
228 /* Are there any shared blocks here? */
229 flen = 0;
230 cur = xfs_refcountbt_init_cursor(mp, tp, info->agf_bp,
231 info->agno, NULL);
232
233 error = xfs_refcount_find_shared(cur, rec->rm_startblock,
234 rec->rm_blockcount, &fbno, &flen, false);
235
236 xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
237 if (error)
238 return error;
239
240 *stat = flen > 0;
241 return 0;
242}
243
244/*
245 * Format a reverse mapping for getfsmap, having translated rm_startblock
246 * into the appropriate daddr units.
247 */
248STATIC int
249xfs_getfsmap_helper(
250 struct xfs_trans *tp,
251 struct xfs_getfsmap_info *info,
252 struct xfs_rmap_irec *rec,
253 xfs_daddr_t rec_daddr)
254{
255 struct xfs_fsmap fmr;
256 struct xfs_mount *mp = tp->t_mountp;
257 bool shared;
258 int error;
259
260 if (fatal_signal_pending(current))
261 return -EINTR;
262
263 /*
264 * Filter out records that start before our startpoint, if the
265 * caller requested that.
266 */
267 if (xfs_rmap_compare(rec, &info->low) < 0) {
268 rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount);
269 if (info->next_daddr < rec_daddr)
270 info->next_daddr = rec_daddr;
271 return XFS_BTREE_QUERY_RANGE_CONTINUE;
272 }
273
274 /* Are we just counting mappings? */
275 if (info->head->fmh_count == 0) {
276 if (rec_daddr > info->next_daddr)
277 info->head->fmh_entries++;
278
279 if (info->last)
280 return XFS_BTREE_QUERY_RANGE_CONTINUE;
281
282 info->head->fmh_entries++;
283
284 rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount);
285 if (info->next_daddr < rec_daddr)
286 info->next_daddr = rec_daddr;
287 return XFS_BTREE_QUERY_RANGE_CONTINUE;
288 }
289
290 /*
291 * If the record starts past the last physical block we saw,
292 * then we've found a gap. Report the gap as being owned by
293 * whatever the caller specified is the missing owner.
294 */
295 if (rec_daddr > info->next_daddr) {
296 if (info->head->fmh_entries >= info->head->fmh_count)
297 return XFS_BTREE_QUERY_RANGE_ABORT;
298
299 fmr.fmr_device = info->dev;
300 fmr.fmr_physical = info->next_daddr;
301 fmr.fmr_owner = info->missing_owner;
302 fmr.fmr_offset = 0;
303 fmr.fmr_length = rec_daddr - info->next_daddr;
304 fmr.fmr_flags = FMR_OF_SPECIAL_OWNER;
305 error = info->formatter(&fmr, info->format_arg);
306 if (error)
307 return error;
308 info->head->fmh_entries++;
309 }
310
311 if (info->last)
312 goto out;
313
314 /* Fill out the extent we found */
315 if (info->head->fmh_entries >= info->head->fmh_count)
316 return XFS_BTREE_QUERY_RANGE_ABORT;
317
318 trace_xfs_fsmap_mapping(mp, info->dev, info->agno, rec);
319
320 fmr.fmr_device = info->dev;
321 fmr.fmr_physical = rec_daddr;
322 error = xfs_fsmap_owner_from_rmap(&fmr, rec);
323 if (error)
324 return error;
325 fmr.fmr_offset = XFS_FSB_TO_BB(mp, rec->rm_offset);
326 fmr.fmr_length = XFS_FSB_TO_BB(mp, rec->rm_blockcount);
327 if (rec->rm_flags & XFS_RMAP_UNWRITTEN)
328 fmr.fmr_flags |= FMR_OF_PREALLOC;
329 if (rec->rm_flags & XFS_RMAP_ATTR_FORK)
330 fmr.fmr_flags |= FMR_OF_ATTR_FORK;
331 if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
332 fmr.fmr_flags |= FMR_OF_EXTENT_MAP;
333 if (fmr.fmr_flags == 0) {
334 error = xfs_getfsmap_is_shared(tp, info, rec, &shared);
335 if (error)
336 return error;
337 if (shared)
338 fmr.fmr_flags |= FMR_OF_SHARED;
339 }
340 error = info->formatter(&fmr, info->format_arg);
341 if (error)
342 return error;
343 info->head->fmh_entries++;
344
345out:
346 rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount);
347 if (info->next_daddr < rec_daddr)
348 info->next_daddr = rec_daddr;
349 return XFS_BTREE_QUERY_RANGE_CONTINUE;
350}
351
352/* Transform a rmapbt irec into a fsmap */
353STATIC int
354xfs_getfsmap_datadev_helper(
355 struct xfs_btree_cur *cur,
356 struct xfs_rmap_irec *rec,
357 void *priv)
358{
359 struct xfs_mount *mp = cur->bc_mp;
360 struct xfs_getfsmap_info *info = priv;
361 xfs_fsblock_t fsb;
362 xfs_daddr_t rec_daddr;
363
364 fsb = XFS_AGB_TO_FSB(mp, cur->bc_private.a.agno, rec->rm_startblock);
365 rec_daddr = XFS_FSB_TO_DADDR(mp, fsb);
366
367 return xfs_getfsmap_helper(cur->bc_tp, info, rec, rec_daddr);
368}
369
4c934c7d
DW		 370/* Transform a rtbitmap "record" into a fsmap */
371STATIC int
372xfs_getfsmap_rtdev_rtbitmap_helper(
373 struct xfs_trans *tp,
374 struct xfs_rtalloc_rec *rec,
375 void *priv)
376{
377 struct xfs_mount *mp = tp->t_mountp;
378 struct xfs_getfsmap_info *info = priv;
379 struct xfs_rmap_irec irec;
380 xfs_daddr_t rec_daddr;
381
382 rec_daddr = XFS_FSB_TO_BB(mp, rec->ar_startblock);
383
384 irec.rm_startblock = rec->ar_startblock;
385 irec.rm_blockcount = rec->ar_blockcount;
386 irec.rm_owner = XFS_RMAP_OWN_NULL; /* "free" */
387 irec.rm_offset = 0;
388 irec.rm_flags = 0;
389
390 return xfs_getfsmap_helper(tp, info, &irec, rec_daddr);
391}
392
a1cae728
DW		 393/* Transform a bnobt irec into a fsmap */
394STATIC int
395xfs_getfsmap_datadev_bnobt_helper(
396 struct xfs_btree_cur *cur,
397 struct xfs_alloc_rec_incore *rec,
398 void *priv)
399{
400 struct xfs_mount *mp = cur->bc_mp;
401 struct xfs_getfsmap_info *info = priv;
402 struct xfs_rmap_irec irec;
403 xfs_daddr_t rec_daddr;
404
405 rec_daddr = XFS_AGB_TO_DADDR(mp, cur->bc_private.a.agno,
406 rec->ar_startblock);
407
408 irec.rm_startblock = rec->ar_startblock;
409 irec.rm_blockcount = rec->ar_blockcount;
410 irec.rm_owner = XFS_RMAP_OWN_NULL; /* "free" */
411 irec.rm_offset = 0;
412 irec.rm_flags = 0;
413
414 return xfs_getfsmap_helper(cur->bc_tp, info, &irec, rec_daddr);
415}
416
e89c0413
DW		 417/* Set rmap flags based on the getfsmap flags */
418static void
419xfs_getfsmap_set_irec_flags(
420 struct xfs_rmap_irec *irec,
421 struct xfs_fsmap *fmr)
422{
423 irec->rm_flags = 0;
424 if (fmr->fmr_flags & FMR_OF_ATTR_FORK)
425 irec->rm_flags |= XFS_RMAP_ATTR_FORK;
426 if (fmr->fmr_flags & FMR_OF_EXTENT_MAP)
427 irec->rm_flags |= XFS_RMAP_BMBT_BLOCK;
428 if (fmr->fmr_flags & FMR_OF_PREALLOC)
429 irec->rm_flags |= XFS_RMAP_UNWRITTEN;
430}
431
432/* Execute a getfsmap query against the log device. */
433STATIC int
434xfs_getfsmap_logdev(
435 struct xfs_trans *tp,
436 struct xfs_fsmap *keys,
437 struct xfs_getfsmap_info *info)
438{
439 struct xfs_mount *mp = tp->t_mountp;
440 struct xfs_rmap_irec rmap;
441 int error;
442
443 /* Set up search keys */
444 info->low.rm_startblock = XFS_BB_TO_FSBT(mp, keys[0].fmr_physical);
445 info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset);
446 error = xfs_fsmap_owner_to_rmap(&info->low, keys);
447 if (error)
448 return error;
449 info->low.rm_blockcount = 0;
450 xfs_getfsmap_set_irec_flags(&info->low, &keys[0]);
451
452 error = xfs_fsmap_owner_to_rmap(&info->high, keys + 1);
453 if (error)
454 return error;
455 info->high.rm_startblock = -1U;
456 info->high.rm_owner = ULLONG_MAX;
457 info->high.rm_offset = ULLONG_MAX;
458 info->high.rm_blockcount = 0;
459 info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS;
460 info->missing_owner = XFS_FMR_OWN_FREE;
461
462 trace_xfs_fsmap_low_key(mp, info->dev, info->agno, &info->low);
463 trace_xfs_fsmap_high_key(mp, info->dev, info->agno, &info->high);
464
465 if (keys[0].fmr_physical > 0)
466 return 0;
467
468 /* Fabricate an rmap entry for the external log device. */
469 rmap.rm_startblock = 0;
470 rmap.rm_blockcount = mp->m_sb.sb_logblocks;
471 rmap.rm_owner = XFS_RMAP_OWN_LOG;
472 rmap.rm_offset = 0;
473 rmap.rm_flags = 0;
474
475 return xfs_getfsmap_helper(tp, info, &rmap, 0);
476}
477
4c934c7d
DW		 478/* Execute a getfsmap query against the realtime device. */
479STATIC int
480__xfs_getfsmap_rtdev(
481 struct xfs_trans *tp,
482 struct xfs_fsmap *keys,
483 int (*query_fn)(struct xfs_trans *,
484 struct xfs_getfsmap_info *),
485 struct xfs_getfsmap_info *info)
486{
487 struct xfs_mount *mp = tp->t_mountp;
488 xfs_fsblock_t start_fsb;
489 xfs_fsblock_t end_fsb;
490 xfs_daddr_t eofs;
491 int error = 0;
492
493 eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
494 if (keys[0].fmr_physical >= eofs)
495 return 0;
496 if (keys[1].fmr_physical >= eofs)
497 keys[1].fmr_physical = eofs - 1;
498 start_fsb = XFS_BB_TO_FSBT(mp, keys[0].fmr_physical);
499 end_fsb = XFS_BB_TO_FSB(mp, keys[1].fmr_physical);
500
501 /* Set up search keys */
502 info->low.rm_startblock = start_fsb;
503 error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]);
504 if (error)
505 return error;
506 info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset);
507 info->low.rm_blockcount = 0;
508 xfs_getfsmap_set_irec_flags(&info->low, &keys[0]);
509
510 info->high.rm_startblock = end_fsb;
511 error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]);
512 if (error)
513 return error;
514 info->high.rm_offset = XFS_BB_TO_FSBT(mp, keys[1].fmr_offset);
515 info->high.rm_blockcount = 0;
516 xfs_getfsmap_set_irec_flags(&info->high, &keys[1]);
517
518 trace_xfs_fsmap_low_key(mp, info->dev, info->agno, &info->low);
519 trace_xfs_fsmap_high_key(mp, info->dev, info->agno, &info->high);
520
521 return query_fn(tp, info);
522}
523
524/* Actually query the realtime bitmap. */
525STATIC int
526xfs_getfsmap_rtdev_rtbitmap_query(
527 struct xfs_trans *tp,
528 struct xfs_getfsmap_info *info)
529{
530 struct xfs_rtalloc_rec alow;
531 struct xfs_rtalloc_rec ahigh;
532 int error;
533
534 xfs_ilock(tp->t_mountp->m_rbmip, XFS_ILOCK_SHARED);
535
536 alow.ar_startblock = info->low.rm_startblock;
537 ahigh.ar_startblock = info->high.rm_startblock;
538 error = xfs_rtalloc_query_range(tp, &alow, &ahigh,
539 xfs_getfsmap_rtdev_rtbitmap_helper, info);
540 if (error)
541 goto err;
542
543 /* Report any gaps at the end of the rtbitmap */
544 info->last = true;
545 error = xfs_getfsmap_rtdev_rtbitmap_helper(tp, &ahigh, info);
546 if (error)
547 goto err;
548err:
549 xfs_iunlock(tp->t_mountp->m_rbmip, XFS_ILOCK_SHARED);
550 return error;
551}
552
553/* Execute a getfsmap query against the realtime device rtbitmap. */
554STATIC int
555xfs_getfsmap_rtdev_rtbitmap(
556 struct xfs_trans *tp,
557 struct xfs_fsmap *keys,
558 struct xfs_getfsmap_info *info)
559{
560 info->missing_owner = XFS_FMR_OWN_UNKNOWN;
561 return __xfs_getfsmap_rtdev(tp, keys, xfs_getfsmap_rtdev_rtbitmap_query,
562 info);
563}
564
e89c0413
DW		 565/* Execute a getfsmap query against the regular data device. */
566STATIC int
567__xfs_getfsmap_datadev(
568 struct xfs_trans *tp,
569 struct xfs_fsmap *keys,
570 struct xfs_getfsmap_info *info,
571 int (*query_fn)(struct xfs_trans *,
572 struct xfs_getfsmap_info *,
573 struct xfs_btree_cur **,
574 void *),
575 void *priv)
576{
577 struct xfs_mount *mp = tp->t_mountp;
578 struct xfs_btree_cur *bt_cur = NULL;
579 xfs_fsblock_t start_fsb;
580 xfs_fsblock_t end_fsb;
581 xfs_agnumber_t start_ag;
582 xfs_agnumber_t end_ag;
583 xfs_daddr_t eofs;
584 int error = 0;
585
586 eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
587 if (keys[0].fmr_physical >= eofs)
588 return 0;
589 if (keys[1].fmr_physical >= eofs)
590 keys[1].fmr_physical = eofs - 1;
591 start_fsb = XFS_DADDR_TO_FSB(mp, keys[0].fmr_physical);
592 end_fsb = XFS_DADDR_TO_FSB(mp, keys[1].fmr_physical);
593
594 /*
595 * Convert the fsmap low/high keys to AG based keys. Initialize
596 * low to the fsmap low key and max out the high key to the end
597 * of the AG.
598 */
599 info->low.rm_startblock = XFS_FSB_TO_AGBNO(mp, start_fsb);
600 info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset);
601 error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]);
602 if (error)
603 return error;
604 info->low.rm_blockcount = 0;
605 xfs_getfsmap_set_irec_flags(&info->low, &keys[0]);
606
607 info->high.rm_startblock = -1U;
608 info->high.rm_owner = ULLONG_MAX;
609 info->high.rm_offset = ULLONG_MAX;
610 info->high.rm_blockcount = 0;
611 info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS;
612
613 start_ag = XFS_FSB_TO_AGNO(mp, start_fsb);
614 end_ag = XFS_FSB_TO_AGNO(mp, end_fsb);
615
616 /* Query each AG */
617 for (info->agno = start_ag; info->agno <= end_ag; info->agno++) {
618 /*
619 * Set the AG high key from the fsmap high key if this
620 * is the last AG that we're querying.
621 */
622 if (info->agno == end_ag) {
623 info->high.rm_startblock = XFS_FSB_TO_AGBNO(mp,
624 end_fsb);
625 info->high.rm_offset = XFS_BB_TO_FSBT(mp,
626 keys[1].fmr_offset);
627 error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]);
628 if (error)
629 goto err;
630 xfs_getfsmap_set_irec_flags(&info->high, &keys[1]);
631 }
632
633 if (bt_cur) {
634 xfs_btree_del_cursor(bt_cur, XFS_BTREE_NOERROR);
635 bt_cur = NULL;
636 xfs_trans_brelse(tp, info->agf_bp);
637 info->agf_bp = NULL;
638 }
639
640 error = xfs_alloc_read_agf(mp, tp, info->agno, 0,
641 &info->agf_bp);
642 if (error)
643 goto err;
644
645 trace_xfs_fsmap_low_key(mp, info->dev, info->agno, &info->low);
646 trace_xfs_fsmap_high_key(mp, info->dev, info->agno,
647 &info->high);
648
649 error = query_fn(tp, info, &bt_cur, priv);
650 if (error)
651 goto err;
652
653 /*
654 * Set the AG low key to the start of the AG prior to
655 * moving on to the next AG.
656 */
657 if (info->agno == start_ag) {
658 info->low.rm_startblock = 0;
659 info->low.rm_owner = 0;
660 info->low.rm_offset = 0;
661 info->low.rm_flags = 0;
662 }
663 }
664
665 /* Report any gap at the end of the AG */
666 info->last = true;
667 error = query_fn(tp, info, &bt_cur, priv);
668 if (error)
669 goto err;
670
671err:
672 if (bt_cur)
673 xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR :
674 XFS_BTREE_NOERROR);
675 if (info->agf_bp) {
676 xfs_trans_brelse(tp, info->agf_bp);
677 info->agf_bp = NULL;
678 }
679
680 return error;
681}
682
683/* Actually query the rmap btree. */
684STATIC int
685xfs_getfsmap_datadev_rmapbt_query(
686 struct xfs_trans *tp,
687 struct xfs_getfsmap_info *info,
688 struct xfs_btree_cur **curpp,
689 void *priv)
690{
691 /* Report any gap at the end of the last AG. */
692 if (info->last)
693 return xfs_getfsmap_datadev_helper(*curpp, &info->high, info);
694
695 /* Allocate cursor for this AG and query_range it. */
696 *curpp = xfs_rmapbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
697 info->agno);
698 return xfs_rmap_query_range(*curpp, &info->low, &info->high,
699 xfs_getfsmap_datadev_helper, info);
700}
701
702/* Execute a getfsmap query against the regular data device rmapbt. */
703STATIC int
704xfs_getfsmap_datadev_rmapbt(
705 struct xfs_trans *tp,
706 struct xfs_fsmap *keys,
707 struct xfs_getfsmap_info *info)
708{
709 info->missing_owner = XFS_FMR_OWN_FREE;
710 return __xfs_getfsmap_datadev(tp, keys, info,
711 xfs_getfsmap_datadev_rmapbt_query, NULL);
712}
713
a1cae728
DW		 714/* Actually query the bno btree. */
715STATIC int
716xfs_getfsmap_datadev_bnobt_query(
717 struct xfs_trans *tp,
718 struct xfs_getfsmap_info *info,
719 struct xfs_btree_cur **curpp,
720 void *priv)
721{
722 struct xfs_alloc_rec_incore *key = priv;
723
724 /* Report any gap at the end of the last AG. */
725 if (info->last)
726 return xfs_getfsmap_datadev_bnobt_helper(*curpp, &key[1], info);
727
728 /* Allocate cursor for this AG and query_range it. */
729 *curpp = xfs_allocbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
730 info->agno, XFS_BTNUM_BNO);
731 key->ar_startblock = info->low.rm_startblock;
732 key[1].ar_startblock = info->high.rm_startblock;
733 return xfs_alloc_query_range(*curpp, key, &key[1],
734 xfs_getfsmap_datadev_bnobt_helper, info);
735}
736
737/* Execute a getfsmap query against the regular data device's bnobt. */
738STATIC int
739xfs_getfsmap_datadev_bnobt(
740 struct xfs_trans *tp,
741 struct xfs_fsmap *keys,
742 struct xfs_getfsmap_info *info)
743{
744 struct xfs_alloc_rec_incore akeys[2];
745
746 info->missing_owner = XFS_FMR_OWN_UNKNOWN;
747 return __xfs_getfsmap_datadev(tp, keys, info,
748 xfs_getfsmap_datadev_bnobt_query, &akeys[0]);
749}
750
e89c0413
DW		 751/* Do we recognize the device? */
752STATIC bool
753xfs_getfsmap_is_valid_device(
754 struct xfs_mount *mp,
755 struct xfs_fsmap *fm)
756{
757 if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX ||
758 fm->fmr_device == new_encode_dev(mp->m_ddev_targp->bt_dev))
759 return true;
760 if (mp->m_logdev_targp &&
761 fm->fmr_device == new_encode_dev(mp->m_logdev_targp->bt_dev))
762 return true;
4c934c7d
DW		 763 if (mp->m_rtdev_targp &&
764 fm->fmr_device == new_encode_dev(mp->m_rtdev_targp->bt_dev))
765 return true;
e89c0413
DW		 766 return false;
767}
768
769/* Ensure that the low key is less than the high key. */
770STATIC bool
771xfs_getfsmap_check_keys(
772 struct xfs_fsmap *low_key,
773 struct xfs_fsmap *high_key)
774{
775 if (low_key->fmr_device > high_key->fmr_device)
776 return false;
777 if (low_key->fmr_device < high_key->fmr_device)
778 return true;
779
780 if (low_key->fmr_physical > high_key->fmr_physical)
781 return false;
782 if (low_key->fmr_physical < high_key->fmr_physical)
783 return true;
784
785 if (low_key->fmr_owner > high_key->fmr_owner)
786 return false;
787 if (low_key->fmr_owner < high_key->fmr_owner)
788 return true;
789
790 if (low_key->fmr_offset > high_key->fmr_offset)
791 return false;
792 if (low_key->fmr_offset < high_key->fmr_offset)
793 return true;
794
795 return false;
796}
797
4c934c7d 798#define XFS_GETFSMAP_DEVS 3
e89c0413
DW		 799/*
800 * Get filesystem's extents as described in head, and format for
801 * output. Calls formatter to fill the user's buffer until all
802 * extents are mapped, until the passed-in head->fmh_count slots have
803 * been filled, or until the formatter short-circuits the loop, if it
804 * is tracking filled-in extents on its own.
805 *
806 * Key to Confusion
807 * ----------------
808 * There are multiple levels of keys and counters at work here:
809 * xfs_fsmap_head.fmh_keys -- low and high fsmap keys passed in;
810 * these reflect fs-wide sector addrs.
811 * dkeys -- fmh_keys used to query each device;
812 * these are fmh_keys but w/ the low key
813 * bumped up by fmr_length.
814 * xfs_getfsmap_info.next_daddr -- next disk addr we expect to see; this
815 * is how we detect gaps in the fsmap
816 records and report them.
817 * xfs_getfsmap_info.low/high -- per-AG low/high keys computed from
818 * dkeys; used to query the metadata.
819 */
820int
821xfs_getfsmap(
822 struct xfs_mount *mp,
823 struct xfs_fsmap_head *head,
824 xfs_fsmap_format_t formatter,
825 void *arg)
826{
827 struct xfs_trans *tp = NULL;
828 struct xfs_fsmap dkeys[2]; /* per-dev keys */
829 struct xfs_getfsmap_dev handlers[XFS_GETFSMAP_DEVS];
830 struct xfs_getfsmap_info info = {0};
831 int i;
832 int error = 0;
833
e89c0413
DW		 834 if (head->fmh_iflags & ~FMH_IF_VALID)
835 return -EINVAL;
836 if (!xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[0]) ||
837 !xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[1]))
838 return -EINVAL;
839
840 head->fmh_entries = 0;
841
842 /* Set up our device handlers. */
843 memset(handlers, 0, sizeof(handlers));
844 handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev);
a1cae728
DW		 845 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
846 handlers[0].fn = xfs_getfsmap_datadev_rmapbt;
847 else
848 handlers[0].fn = xfs_getfsmap_datadev_bnobt;
e89c0413
DW		 849 if (mp->m_logdev_targp != mp->m_ddev_targp) {
850 handlers[1].dev = new_encode_dev(mp->m_logdev_targp->bt_dev);
851 handlers[1].fn = xfs_getfsmap_logdev;
852 }
4c934c7d
DW		 853 if (mp->m_rtdev_targp) {
854 handlers[2].dev = new_encode_dev(mp->m_rtdev_targp->bt_dev);
855 handlers[2].fn = xfs_getfsmap_rtdev_rtbitmap;
856 }
e89c0413
DW		 857
858 xfs_sort(handlers, XFS_GETFSMAP_DEVS, sizeof(struct xfs_getfsmap_dev),
859 xfs_getfsmap_dev_compare);
860
861 /*
862 * To continue where we left off, we allow userspace to use the
863 * last mapping from a previous call as the low key of the next.
864 * This is identified by a non-zero length in the low key. We
865 * have to increment the low key in this scenario to ensure we
866 * don't return the same mapping again, and instead return the
867 * very next mapping.
868 *
869 * If the low key mapping refers to file data, the same physical
870 * blocks could be mapped to several other files/offsets.
871 * According to rmapbt record ordering, the minimal next
872 * possible record for the block range is the next starting
873 * offset in the same inode. Therefore, bump the file offset to
874 * continue the search appropriately. For all other low key
875 * mapping types (attr blocks, metadata), bump the physical
876 * offset as there can be no other mapping for the same physical
877 * block range.
878 */
879 dkeys[0] = head->fmh_keys[0];
880 if (dkeys[0].fmr_flags & (FMR_OF_SPECIAL_OWNER | FMR_OF_EXTENT_MAP)) {
881 dkeys[0].fmr_physical += dkeys[0].fmr_length;
882 dkeys[0].fmr_owner = 0;
883 if (dkeys[0].fmr_offset)
884 return -EINVAL;
885 } else
886 dkeys[0].fmr_offset += dkeys[0].fmr_length;
887 dkeys[0].fmr_length = 0;
888 memset(&dkeys[1], 0xFF, sizeof(struct xfs_fsmap));
889
890 if (!xfs_getfsmap_check_keys(dkeys, &head->fmh_keys[1]))
891 return -EINVAL;
892
893 info.next_daddr = head->fmh_keys[0].fmr_physical +
894 head->fmh_keys[0].fmr_length;
895 info.formatter = formatter;
896 info.format_arg = arg;
897 info.head = head;
898
899 /* For each device we support... */
900 for (i = 0; i < XFS_GETFSMAP_DEVS; i++) {
901 /* Is this device within the range the user asked for? */
902 if (!handlers[i].fn)
903 continue;
904 if (head->fmh_keys[0].fmr_device > handlers[i].dev)
905 continue;
906 if (head->fmh_keys[1].fmr_device < handlers[i].dev)
907 break;
908
909 /*
910 * If this device number matches the high key, we have
911 * to pass the high key to the handler to limit the
912 * query results. If the device number exceeds the
913 * low key, zero out the low key so that we get
914 * everything from the beginning.
915 */
916 if (handlers[i].dev == head->fmh_keys[1].fmr_device)
917 dkeys[1] = head->fmh_keys[1];
918 if (handlers[i].dev > head->fmh_keys[0].fmr_device)
919 memset(&dkeys[0], 0, sizeof(struct xfs_fsmap));
920
921 error = xfs_trans_alloc_empty(mp, &tp);
922 if (error)
923 break;
924
925 info.dev = handlers[i].dev;
926 info.last = false;
927 info.agno = NULLAGNUMBER;
928 error = handlers[i].fn(tp, dkeys, &info);
929 if (error)
930 break;
931 xfs_trans_cancel(tp);
932 tp = NULL;
933 info.next_daddr = 0;
934 }
935
936 if (tp)
937 xfs_trans_cancel(tp);
938 head->fmh_oflags = FMH_OF_DEV_T;
939 return error;
940}
Linux 6.x block layer and io_uring tree(s)