1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2017 Oracle. All Rights Reserved.
4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
5 */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_mount.h"
13 #include "xfs_inode.h"
14 #include "xfs_trans.h"
15 #include "xfs_btree.h"
16 #include "xfs_rmap_btree.h"
17 #include "xfs_trace.h"
18 #include "xfs_rmap.h"
19 #include "xfs_alloc.h"
20 #include "xfs_bit.h"
21 #include <linux/fsmap.h>
22 #include "xfs_fsmap.h"
23 #include "xfs_refcount.h"
24 #include "xfs_refcount_btree.h"
25 #include "xfs_alloc_btree.h"
26 #include "xfs_rtbitmap.h"
27 #include "xfs_ag.h"
28
29 /* Convert an xfs_fsmap to an fsmap. */
30 static void
31 xfs_fsmap_from_internal(
32 struct fsmap *dest,
33 struct xfs_fsmap *src)
34 {
35 dest->fmr_device = src->fmr_device;
36 dest->fmr_flags = src->fmr_flags;
37 dest->fmr_physical = BBTOB(src->fmr_physical);
38 dest->fmr_owner = src->fmr_owner;
39 dest->fmr_offset = BBTOB(src->fmr_offset);
40 dest->fmr_length = BBTOB(src->fmr_length);
41 dest->fmr_reserved[0] = 0;
42 dest->fmr_reserved[1] = 0;
43 dest->fmr_reserved[2] = 0;
44 }
45
46 /* Convert an fsmap to an xfs_fsmap. */
47 void
48 xfs_fsmap_to_internal(
49 struct xfs_fsmap *dest,
50 struct fsmap *src)
51 {
52 dest->fmr_device = src->fmr_device;
53 dest->fmr_flags = src->fmr_flags;
54 dest->fmr_physical = BTOBBT(src->fmr_physical);
55 dest->fmr_owner = src->fmr_owner;
56 dest->fmr_offset = BTOBBT(src->fmr_offset);
57 dest->fmr_length = BTOBBT(src->fmr_length);
58 }
59
60 /* Convert an fsmap owner into an rmapbt owner. */
61 static int
62 xfs_fsmap_owner_to_rmap(
63 struct xfs_rmap_irec *dest,
64 const struct xfs_fsmap *src)
65 {
66 if (!(src->fmr_flags & FMR_OF_SPECIAL_OWNER)) {
67 dest->rm_owner = src->fmr_owner;
68 return 0;
69 }
70
71 switch (src->fmr_owner) {
72 case 0: /* "lowest owner id possible" */
73 case -1ULL: /* "highest owner id possible" */
74 dest->rm_owner = src->fmr_owner;
75 break;
76 case XFS_FMR_OWN_FREE:
77 dest->rm_owner = XFS_RMAP_OWN_NULL;
78 break;
79 case XFS_FMR_OWN_UNKNOWN:
80 dest->rm_owner = XFS_RMAP_OWN_UNKNOWN;
81 break;
82 case XFS_FMR_OWN_FS:
83 dest->rm_owner = XFS_RMAP_OWN_FS;
84 break;
85 case XFS_FMR_OWN_LOG:
86 dest->rm_owner = XFS_RMAP_OWN_LOG;
87 break;
88 case XFS_FMR_OWN_AG:
89 dest->rm_owner = XFS_RMAP_OWN_AG;
90 break;
91 case XFS_FMR_OWN_INOBT:
92 dest->rm_owner = XFS_RMAP_OWN_INOBT;
93 break;
94 case XFS_FMR_OWN_INODES:
95 dest->rm_owner = XFS_RMAP_OWN_INODES;
96 break;
97 case XFS_FMR_OWN_REFC:
98 dest->rm_owner = XFS_RMAP_OWN_REFC;
99 break;
100 case XFS_FMR_OWN_COW:
101 dest->rm_owner = XFS_RMAP_OWN_COW;
102 break;
103 case XFS_FMR_OWN_DEFECTIVE: /* not implemented */
104 /* fall through */
105 default:
106 return -EINVAL;
107 }
108 return 0;
109 }
110
111 /* Convert an rmapbt owner into an fsmap owner. */
112 static int
113 xfs_fsmap_owner_from_rmap(
114 struct xfs_fsmap *dest,
115 const struct xfs_rmap_irec *src)
116 {
117 dest->fmr_flags = 0;
118 if (!XFS_RMAP_NON_INODE_OWNER(src->rm_owner)) {
119 dest->fmr_owner = src->rm_owner;
120 return 0;
121 }
122 dest->fmr_flags |= FMR_OF_SPECIAL_OWNER;
123
124 switch (src->rm_owner) {
125 case XFS_RMAP_OWN_FS:
126 dest->fmr_owner = XFS_FMR_OWN_FS;
127 break;
128 case XFS_RMAP_OWN_LOG:
129 dest->fmr_owner = XFS_FMR_OWN_LOG;
130 break;
131 case XFS_RMAP_OWN_AG:
132 dest->fmr_owner = XFS_FMR_OWN_AG;
133 break;
134 case XFS_RMAP_OWN_INOBT:
135 dest->fmr_owner = XFS_FMR_OWN_INOBT;
136 break;
137 case XFS_RMAP_OWN_INODES:
138 dest->fmr_owner = XFS_FMR_OWN_INODES;
139 break;
140 case XFS_RMAP_OWN_REFC:
141 dest->fmr_owner = XFS_FMR_OWN_REFC;
142 break;
143 case XFS_RMAP_OWN_COW:
144 dest->fmr_owner = XFS_FMR_OWN_COW;
145 break;
146 case XFS_RMAP_OWN_NULL: /* "free" */
147 dest->fmr_owner = XFS_FMR_OWN_FREE;
148 break;
149 default:
150 ASSERT(0);
151 return -EFSCORRUPTED;
152 }
153 return 0;
154 }
155
156 /* getfsmap query state */
157 struct xfs_getfsmap_info {
158 struct xfs_fsmap_head *head;
159 struct fsmap *fsmap_recs; /* mapping records */
160 struct xfs_buf *agf_bp; /* AGF, for refcount queries */
161 struct xfs_perag *pag; /* AG info, if applicable */
162 xfs_daddr_t next_daddr; /* next daddr we expect */
163 /* daddr of low fsmap key when we're using the rtbitmap */
164 xfs_daddr_t low_daddr;
165 xfs_daddr_t end_daddr; /* daddr of high fsmap key */
166 u64 missing_owner; /* owner of holes */
167 u32 dev; /* device id */
168 /*
169 * Low rmap key for the query. If low.rm_blockcount is nonzero, this
170 * is the second (or later) call to retrieve the recordset in pieces.
171 * xfs_getfsmap_rec_before_start will compare all records retrieved
172 * by the rmapbt query to filter out any records that start before
173 * the last record.
174 */
175 struct xfs_rmap_irec low;
176 struct xfs_rmap_irec high; /* high rmap key */
177 bool last; /* last extent? */
178 };
179
180 /* Associate a device with a getfsmap handler. */
181 struct xfs_getfsmap_dev {
182 u32 dev;
183 int (*fn)(struct xfs_trans *tp,
184 const struct xfs_fsmap *keys,
185 struct xfs_getfsmap_info *info);
186 sector_t nr_sectors;
187 };
188
189 /* Compare two getfsmap device handlers. */
190 static int
191 xfs_getfsmap_dev_compare(
192 const void *p1,
193 const void *p2)
194 {
195 const struct xfs_getfsmap_dev *d1 = p1;
196 const struct xfs_getfsmap_dev *d2 = p2;
197
198 return d1->dev - d2->dev;
199 }
200
201 /* Decide if this mapping is shared. */
202 STATIC int
203 xfs_getfsmap_is_shared(
204 struct xfs_trans *tp,
205 struct xfs_getfsmap_info *info,
206 const struct xfs_rmap_irec *rec,
207 bool *stat)
208 {
209 struct xfs_mount *mp = tp->t_mountp;
210 struct xfs_btree_cur *cur;
211 xfs_agblock_t fbno;
212 xfs_extlen_t flen;
213 int error;
214
215 *stat = false;
216 if (!xfs_has_reflink(mp))
217 return 0;
218 /* rt files will have no perag structure */
219 if (!info->pag)
220 return 0;
221
222 /* Are there any shared blocks here? */
223 flen = 0;
224 cur = xfs_refcountbt_init_cursor(mp, tp, info->agf_bp, info->pag);
225
226 error = xfs_refcount_find_shared(cur, rec->rm_startblock,
227 rec->rm_blockcount, &fbno, &flen, false);
228
229 xfs_btree_del_cursor(cur, error);
230 if (error)
231 return error;
232
233 *stat = flen > 0;
234 return 0;
235 }
236
237 static inline void
238 xfs_getfsmap_format(
239 struct xfs_mount *mp,
240 struct xfs_fsmap *xfm,
241 struct xfs_getfsmap_info *info)
242 {
243 struct fsmap *rec;
244
245 trace_xfs_getfsmap_mapping(mp, xfm);
246
247 rec = &info->fsmap_recs[info->head->fmh_entries++];
248 xfs_fsmap_from_internal(rec, xfm);
249 }
250
251 static inline bool
252 xfs_getfsmap_rec_before_start(
253 struct xfs_getfsmap_info *info,
254 const struct xfs_rmap_irec *rec,
255 xfs_daddr_t rec_daddr)
256 {
257 if (info->low_daddr != XFS_BUF_DADDR_NULL)
258 return rec_daddr < info->low_daddr;
259 if (info->low.rm_blockcount)
260 return xfs_rmap_compare(rec, &info->low) < 0;
261 return false;
262 }
263
264 /*
265 * Format a reverse mapping for getfsmap, having translated rm_startblock
266 * into the appropriate daddr units. Pass in a nonzero @len_daddr if the
267 * length could be larger than rm_blockcount in struct xfs_rmap_irec.
268 */
269 STATIC int
270 xfs_getfsmap_helper(
271 struct xfs_trans *tp,
272 struct xfs_getfsmap_info *info,
273 const struct xfs_rmap_irec *rec,
274 xfs_daddr_t rec_daddr,
275 xfs_daddr_t len_daddr)
276 {
277 struct xfs_fsmap fmr;
278 struct xfs_mount *mp = tp->t_mountp;
279 bool shared;
280 int error;
281
282 if (fatal_signal_pending(current))
283 return -EINTR;
284
285 if (len_daddr == 0)
286 len_daddr = XFS_FSB_TO_BB(mp, rec->rm_blockcount);
287
288 /*
289 * Filter out records that start before our startpoint, if the
290 * caller requested that.
291 */
292 if (xfs_getfsmap_rec_before_start(info, rec, rec_daddr)) {
293 rec_daddr += len_daddr;
294 if (info->next_daddr < rec_daddr)
295 info->next_daddr = rec_daddr;
296 return 0;
297 }
298
299 /*
300 * For an info->last query, we're looking for a gap between the last
301 * mapping emitted and the high key specified by userspace. If the
302 * user's query spans less than 1 fsblock, then info->high and
303 * info->low will have the same rm_startblock, which causes rec_daddr
304 * and next_daddr to be the same. Therefore, use the end_daddr that
305 * we calculated from userspace's high key to synthesize the record.
306 * Note that if the btree query found a mapping, there won't be a gap.
307 */
308 if (info->last && info->end_daddr != XFS_BUF_DADDR_NULL)
309 rec_daddr = info->end_daddr;
310
311 /* Are we just counting mappings? */
312 if (info->head->fmh_count == 0) {
313 if (info->head->fmh_entries == UINT_MAX)
314 return -ECANCELED;
315
316 if (rec_daddr > info->next_daddr)
317 info->head->fmh_entries++;
318
319 if (info->last)
320 return 0;
321
322 info->head->fmh_entries++;
323
324 rec_daddr += len_daddr;
325 if (info->next_daddr < rec_daddr)
326 info->next_daddr = rec_daddr;
327 return 0;
328 }
329
330 /*
331 * If the record starts past the last physical block we saw,
332 * then we've found a gap. Report the gap as being owned by
333 * whatever the caller specified is the missing owner.
334 */
335 if (rec_daddr > info->next_daddr) {
336 if (info->head->fmh_entries >= info->head->fmh_count)
337 return -ECANCELED;
338
339 fmr.fmr_device = info->dev;
340 fmr.fmr_physical = info->next_daddr;
341 fmr.fmr_owner = info->missing_owner;
342 fmr.fmr_offset = 0;
343 fmr.fmr_length = rec_daddr - info->next_daddr;
344 fmr.fmr_flags = FMR_OF_SPECIAL_OWNER;
345 xfs_getfsmap_format(mp, &fmr, info);
346 }
347
348 if (info->last)
349 goto out;
350
351 /* Fill out the extent we found */
352 if (info->head->fmh_entries >= info->head->fmh_count)
353 return -ECANCELED;
354
355 trace_xfs_fsmap_mapping(mp, info->dev,
356 info->pag ? info->pag->pag_agno : NULLAGNUMBER, rec);
357
358 fmr.fmr_device = info->dev;
359 fmr.fmr_physical = rec_daddr;
360 error = xfs_fsmap_owner_from_rmap(&fmr, rec);
361 if (error)
362 return error;
363 fmr.fmr_offset = XFS_FSB_TO_BB(mp, rec->rm_offset);
364 fmr.fmr_length = len_daddr;
365 if (rec->rm_flags & XFS_RMAP_UNWRITTEN)
366 fmr.fmr_flags |= FMR_OF_PREALLOC;
367 if (rec->rm_flags & XFS_RMAP_ATTR_FORK)
368 fmr.fmr_flags |= FMR_OF_ATTR_FORK;
369 if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
370 fmr.fmr_flags |= FMR_OF_EXTENT_MAP;
371 if (fmr.fmr_flags == 0) {
372 error = xfs_getfsmap_is_shared(tp, info, rec, &shared);
373 if (error)
374 return error;
375 if (shared)
376 fmr.fmr_flags |= FMR_OF_SHARED;
377 }
378
379 xfs_getfsmap_format(mp, &fmr, info);
380 out:
381 rec_daddr += len_daddr;
382 if (info->next_daddr < rec_daddr)
383 info->next_daddr = rec_daddr;
384 return 0;
385 }
386
387 /* Transform a rmapbt irec into a fsmap */
388 STATIC int
389 xfs_getfsmap_datadev_helper(
390 struct xfs_btree_cur *cur,
391 const struct xfs_rmap_irec *rec,
392 void *priv)
393 {
394 struct xfs_mount *mp = cur->bc_mp;
395 struct xfs_getfsmap_info *info = priv;
396 xfs_fsblock_t fsb;
397 xfs_daddr_t rec_daddr;
398
399 fsb = XFS_AGB_TO_FSB(mp, cur->bc_ag.pag->pag_agno, rec->rm_startblock);
400 rec_daddr = XFS_FSB_TO_DADDR(mp, fsb);
401
402 return xfs_getfsmap_helper(cur->bc_tp, info, rec, rec_daddr, 0);
403 }
404
405 /* Transform a bnobt irec into a fsmap */
406 STATIC int
407 xfs_getfsmap_datadev_bnobt_helper(
408 struct xfs_btree_cur *cur,
409 const struct xfs_alloc_rec_incore *rec,
410 void *priv)
411 {
412 struct xfs_mount *mp = cur->bc_mp;
413 struct xfs_getfsmap_info *info = priv;
414 struct xfs_rmap_irec irec;
415 xfs_daddr_t rec_daddr;
416
417 rec_daddr = XFS_AGB_TO_DADDR(mp, cur->bc_ag.pag->pag_agno,
418 rec->ar_startblock);
419
420 irec.rm_startblock = rec->ar_startblock;
421 irec.rm_blockcount = rec->ar_blockcount;
422 irec.rm_owner = XFS_RMAP_OWN_NULL; /* "free" */
423 irec.rm_offset = 0;
424 irec.rm_flags = 0;
425
426 return xfs_getfsmap_helper(cur->bc_tp, info, &irec, rec_daddr, 0);
427 }
428
429 /* Set rmap flags based on the getfsmap flags */
430 static void
431 xfs_getfsmap_set_irec_flags(
432 struct xfs_rmap_irec *irec,
433 const struct xfs_fsmap *fmr)
434 {
435 irec->rm_flags = 0;
436 if (fmr->fmr_flags & FMR_OF_ATTR_FORK)
437 irec->rm_flags |= XFS_RMAP_ATTR_FORK;
438 if (fmr->fmr_flags & FMR_OF_EXTENT_MAP)
439 irec->rm_flags |= XFS_RMAP_BMBT_BLOCK;
440 if (fmr->fmr_flags & FMR_OF_PREALLOC)
441 irec->rm_flags |= XFS_RMAP_UNWRITTEN;
442 }
443
444 /* Execute a getfsmap query against the log device. */
445 STATIC int
446 xfs_getfsmap_logdev(
447 struct xfs_trans *tp,
448 const struct xfs_fsmap *keys,
449 struct xfs_getfsmap_info *info)
450 {
451 struct xfs_mount *mp = tp->t_mountp;
452 struct xfs_rmap_irec rmap;
453 xfs_daddr_t rec_daddr, len_daddr;
454 xfs_fsblock_t start_fsb, end_fsb;
455 uint64_t eofs;
456
457 eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
458 if (keys[0].fmr_physical >= eofs)
459 return 0;
460 start_fsb = XFS_BB_TO_FSBT(mp,
461 keys[0].fmr_physical + keys[0].fmr_length);
462 end_fsb = XFS_BB_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical));
463
464 /* Adjust the low key if we are continuing from where we left off. */
465 if (keys[0].fmr_length > 0)
466 info->low_daddr = XFS_FSB_TO_BB(mp, start_fsb);
467
468 trace_xfs_fsmap_low_key_linear(mp, info->dev, start_fsb);
469 trace_xfs_fsmap_high_key_linear(mp, info->dev, end_fsb);
470
471 if (start_fsb > 0)
472 return 0;
473
474 /* Fabricate an rmap entry for the external log device. */
475 rmap.rm_startblock = 0;
476 rmap.rm_blockcount = mp->m_sb.sb_logblocks;
477 rmap.rm_owner = XFS_RMAP_OWN_LOG;
478 rmap.rm_offset = 0;
479 rmap.rm_flags = 0;
480
481 rec_daddr = XFS_FSB_TO_BB(mp, rmap.rm_startblock);
482 len_daddr = XFS_FSB_TO_BB(mp, rmap.rm_blockcount);
483 return xfs_getfsmap_helper(tp, info, &rmap, rec_daddr, len_daddr);
484 }
485
486 #ifdef CONFIG_XFS_RT
487 /* Transform a rtbitmap "record" into a fsmap */
488 STATIC int
489 xfs_getfsmap_rtdev_rtbitmap_helper(
490 struct xfs_mount *mp,
491 struct xfs_trans *tp,
492 const struct xfs_rtalloc_rec *rec,
493 void *priv)
494 {
495 struct xfs_getfsmap_info *info = priv;
496 struct xfs_rmap_irec irec;
497 xfs_rtblock_t rtbno;
498 xfs_daddr_t rec_daddr, len_daddr;
499
500 rtbno = xfs_rtx_to_rtb(mp, rec->ar_startext);
501 rec_daddr = XFS_FSB_TO_BB(mp, rtbno);
502 irec.rm_startblock = rtbno;
503
504 rtbno = xfs_rtx_to_rtb(mp, rec->ar_extcount);
505 len_daddr = XFS_FSB_TO_BB(mp, rtbno);
506 irec.rm_blockcount = rtbno;
507
508 irec.rm_owner = XFS_RMAP_OWN_NULL; /* "free" */
509 irec.rm_offset = 0;
510 irec.rm_flags = 0;
511
512 return xfs_getfsmap_helper(tp, info, &irec, rec_daddr, len_daddr);
513 }
514
515 /* Execute a getfsmap query against the realtime device rtbitmap. */
516 STATIC int
517 xfs_getfsmap_rtdev_rtbitmap(
518 struct xfs_trans *tp,
519 const struct xfs_fsmap *keys,
520 struct xfs_getfsmap_info *info)
521 {
522
523 struct xfs_rtalloc_rec alow = { 0 };
524 struct xfs_rtalloc_rec ahigh = { 0 };
525 struct xfs_mount *mp = tp->t_mountp;
526 xfs_rtblock_t start_rtb;
527 xfs_rtblock_t end_rtb;
528 uint64_t eofs;
529 int error;
530
531 eofs = XFS_FSB_TO_BB(mp, xfs_rtx_to_rtb(mp, mp->m_sb.sb_rextents));
532 if (keys[0].fmr_physical >= eofs)
533 return 0;
534 start_rtb = XFS_BB_TO_FSBT(mp,
535 keys[0].fmr_physical + keys[0].fmr_length);
536 end_rtb = XFS_BB_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical));
537
538 info->missing_owner = XFS_FMR_OWN_UNKNOWN;
539
540 /* Adjust the low key if we are continuing from where we left off. */
541 if (keys[0].fmr_length > 0) {
542 info->low_daddr = XFS_FSB_TO_BB(mp, start_rtb);
543 if (info->low_daddr >= eofs)
544 return 0;
545 }
546
547 trace_xfs_fsmap_low_key_linear(mp, info->dev, start_rtb);
548 trace_xfs_fsmap_high_key_linear(mp, info->dev, end_rtb);
549
550 xfs_rtbitmap_lock_shared(mp, XFS_RBMLOCK_BITMAP);
551
552 /*
553 * Set up query parameters to return free rtextents covering the range
554 * we want.
555 */
556 alow.ar_startext = xfs_rtb_to_rtx(mp, start_rtb);
557 ahigh.ar_startext = xfs_rtb_to_rtxup(mp, end_rtb);
558 error = xfs_rtalloc_query_range(mp, tp, &alow, &ahigh,
559 xfs_getfsmap_rtdev_rtbitmap_helper, info);
560 if (error)
561 goto err;
562
563 /*
564 * Report any gaps at the end of the rtbitmap by simulating a null
565 * rmap starting at the block after the end of the query range.
566 */
567 info->last = true;
568 ahigh.ar_startext = min(mp->m_sb.sb_rextents, ahigh.ar_startext);
569
570 error = xfs_getfsmap_rtdev_rtbitmap_helper(mp, tp, &ahigh, info);
571 if (error)
572 goto err;
573 err:
574 xfs_rtbitmap_unlock_shared(mp, XFS_RBMLOCK_BITMAP);
575 return error;
576 }
577 #endif /* CONFIG_XFS_RT */
578
579 static inline bool
580 rmap_not_shareable(struct xfs_mount *mp, const struct xfs_rmap_irec *r)
581 {
582 if (!xfs_has_reflink(mp))
583 return true;
584 if (XFS_RMAP_NON_INODE_OWNER(r->rm_owner))
585 return true;
586 if (r->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK |
587 XFS_RMAP_UNWRITTEN))
588 return true;
589 return false;
590 }
591
592 /* Execute a getfsmap query against the regular data device. */
593 STATIC int
594 __xfs_getfsmap_datadev(
595 struct xfs_trans *tp,
596 const struct xfs_fsmap *keys,
597 struct xfs_getfsmap_info *info,
598 int (*query_fn)(struct xfs_trans *,
599 struct xfs_getfsmap_info *,
600 struct xfs_btree_cur **,
601 void *),
602 void *priv)
603 {
604 struct xfs_mount *mp = tp->t_mountp;
605 struct xfs_perag *pag;
606 struct xfs_btree_cur *bt_cur = NULL;
607 xfs_fsblock_t start_fsb;
608 xfs_fsblock_t end_fsb;
609 xfs_agnumber_t start_ag;
610 xfs_agnumber_t end_ag;
611 uint64_t eofs;
612 int error = 0;
613
614 eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
615 if (keys[0].fmr_physical >= eofs)
616 return 0;
617 start_fsb = XFS_DADDR_TO_FSB(mp, keys[0].fmr_physical);
618 end_fsb = XFS_DADDR_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical));
619
620 /*
621 * Convert the fsmap low/high keys to AG based keys. Initialize
622 * low to the fsmap low key and max out the high key to the end
623 * of the AG.
624 */
625 info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset);
626 error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]);
627 if (error)
628 return error;
629 info->low.rm_blockcount = XFS_BB_TO_FSBT(mp, keys[0].fmr_length);
630 xfs_getfsmap_set_irec_flags(&info->low, &keys[0]);
631
632 /* Adjust the low key if we are continuing from where we left off. */
633 if (info->low.rm_blockcount == 0) {
634 /* No previous record from which to continue */
635 } else if (rmap_not_shareable(mp, &info->low)) {
636 /* Last record seen was an unshareable extent */
637 info->low.rm_owner = 0;
638 info->low.rm_offset = 0;
639
640 start_fsb += info->low.rm_blockcount;
641 if (XFS_FSB_TO_DADDR(mp, start_fsb) >= eofs)
642 return 0;
643 } else {
644 /* Last record seen was a shareable file data extent */
645 info->low.rm_offset += info->low.rm_blockcount;
646 }
647 info->low.rm_startblock = XFS_FSB_TO_AGBNO(mp, start_fsb);
648
649 info->high.rm_startblock = -1U;
650 info->high.rm_owner = ULLONG_MAX;
651 info->high.rm_offset = ULLONG_MAX;
652 info->high.rm_blockcount = 0;
653 info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS;
654
655 start_ag = XFS_FSB_TO_AGNO(mp, start_fsb);
656 end_ag = XFS_FSB_TO_AGNO(mp, end_fsb);
657
658 for_each_perag_range(mp, start_ag, end_ag, pag) {
659 /*
660 * Set the AG high key from the fsmap high key if this
661 * is the last AG that we're querying.
662 */
663 info->pag = pag;
664 if (pag->pag_agno == end_ag) {
665 info->high.rm_startblock = XFS_FSB_TO_AGBNO(mp,
666 end_fsb);
667 info->high.rm_offset = XFS_BB_TO_FSBT(mp,
668 keys[1].fmr_offset);
669 error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]);
670 if (error)
671 break;
672 xfs_getfsmap_set_irec_flags(&info->high, &keys[1]);
673 }
674
675 if (bt_cur) {
676 xfs_btree_del_cursor(bt_cur, XFS_BTREE_NOERROR);
677 bt_cur = NULL;
678 xfs_trans_brelse(tp, info->agf_bp);
679 info->agf_bp = NULL;
680 }
681
682 error = xfs_alloc_read_agf(pag, tp, 0, &info->agf_bp);
683 if (error)
684 break;
685
686 trace_xfs_fsmap_low_key(mp, info->dev, pag->pag_agno,
687 &info->low);
688 trace_xfs_fsmap_high_key(mp, info->dev, pag->pag_agno,
689 &info->high);
690
691 error = query_fn(tp, info, &bt_cur, priv);
692 if (error)
693 break;
694
695 /*
696 * Set the AG low key to the start of the AG prior to
697 * moving on to the next AG.
698 */
699 if (pag->pag_agno == start_ag)
700 memset(&info->low, 0, sizeof(info->low));
701
702 /*
703 * If this is the last AG, report any gap at the end of it
704 * before we drop the reference to the perag when the loop
705 * terminates.
706 */
707 if (pag->pag_agno == end_ag) {
708 info->last = true;
709 error = query_fn(tp, info, &bt_cur, priv);
710 if (error)
711 break;
712 }
713 info->pag = NULL;
714 }
715
716 if (bt_cur)
717 xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR :
718 XFS_BTREE_NOERROR);
719 if (info->agf_bp) {
720 xfs_trans_brelse(tp, info->agf_bp);
721 info->agf_bp = NULL;
722 }
723 if (info->pag) {
724 xfs_perag_rele(info->pag);
725 info->pag = NULL;
726 } else if (pag) {
727 /* loop termination case */
728 xfs_perag_rele(pag);
729 }
730
731 return error;
732 }
733
734 /* Actually query the rmap btree. */
735 STATIC int
736 xfs_getfsmap_datadev_rmapbt_query(
737 struct xfs_trans *tp,
738 struct xfs_getfsmap_info *info,
739 struct xfs_btree_cur **curpp,
740 void *priv)
741 {
742 /* Report any gap at the end of the last AG. */
743 if (info->last)
744 return xfs_getfsmap_datadev_helper(*curpp, &info->high, info);
745
746 /* Allocate cursor for this AG and query_range it. */
747 *curpp = xfs_rmapbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
748 info->pag);
749 return xfs_rmap_query_range(*curpp, &info->low, &info->high,
750 xfs_getfsmap_datadev_helper, info);
751 }
752
753 /* Execute a getfsmap query against the regular data device rmapbt. */
754 STATIC int
755 xfs_getfsmap_datadev_rmapbt(
756 struct xfs_trans *tp,
757 const struct xfs_fsmap *keys,
758 struct xfs_getfsmap_info *info)
759 {
760 info->missing_owner = XFS_FMR_OWN_FREE;
761 return __xfs_getfsmap_datadev(tp, keys, info,
762 xfs_getfsmap_datadev_rmapbt_query, NULL);
763 }
764
765 /* Actually query the bno btree. */
766 STATIC int
767 xfs_getfsmap_datadev_bnobt_query(
768 struct xfs_trans *tp,
769 struct xfs_getfsmap_info *info,
770 struct xfs_btree_cur **curpp,
771 void *priv)
772 {
773 struct xfs_alloc_rec_incore *key = priv;
774
775 /* Report any gap at the end of the last AG. */
776 if (info->last)
777 return xfs_getfsmap_datadev_bnobt_helper(*curpp, &key[1], info);
778
779 /* Allocate cursor for this AG and query_range it. */
780 *curpp = xfs_bnobt_init_cursor(tp->t_mountp, tp, info->agf_bp,
781 info->pag);
782 key->ar_startblock = info->low.rm_startblock;
783 key[1].ar_startblock = info->high.rm_startblock;
784 return xfs_alloc_query_range(*curpp, key, &key[1],
785 xfs_getfsmap_datadev_bnobt_helper, info);
786 }
787
788 /* Execute a getfsmap query against the regular data device's bnobt. */
789 STATIC int
790 xfs_getfsmap_datadev_bnobt(
791 struct xfs_trans *tp,
792 const struct xfs_fsmap *keys,
793 struct xfs_getfsmap_info *info)
794 {
795 struct xfs_alloc_rec_incore akeys[2];
796
797 memset(akeys, 0, sizeof(akeys));
798 info->missing_owner = XFS_FMR_OWN_UNKNOWN;
799 return __xfs_getfsmap_datadev(tp, keys, info,
800 xfs_getfsmap_datadev_bnobt_query, &akeys[0]);
801 }
802
803 /* Do we recognize the device? */
804 STATIC bool
805 xfs_getfsmap_is_valid_device(
806 struct xfs_mount *mp,
807 struct xfs_fsmap *fm)
808 {
809 if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX ||
810 fm->fmr_device == new_encode_dev(mp->m_ddev_targp->bt_dev))
811 return true;
812 if (mp->m_logdev_targp &&
813 fm->fmr_device == new_encode_dev(mp->m_logdev_targp->bt_dev))
814 return true;
815 if (mp->m_rtdev_targp &&
816 fm->fmr_device == new_encode_dev(mp->m_rtdev_targp->bt_dev))
817 return true;
818 return false;
819 }
820
821 /* Ensure that the low key is less than the high key. */
822 STATIC bool
823 xfs_getfsmap_check_keys(
824 struct xfs_fsmap *low_key,
825 struct xfs_fsmap *high_key)
826 {
827 if (low_key->fmr_flags & (FMR_OF_SPECIAL_OWNER | FMR_OF_EXTENT_MAP)) {
828 if (low_key->fmr_offset)
829 return false;
830 }
831 if (high_key->fmr_flags != -1U &&
832 (high_key->fmr_flags & (FMR_OF_SPECIAL_OWNER |
833 FMR_OF_EXTENT_MAP))) {
834 if (high_key->fmr_offset && high_key->fmr_offset != -1ULL)
835 return false;
836 }
837 if (high_key->fmr_length && high_key->fmr_length != -1ULL)
838 return false;
839
840 if (low_key->fmr_device > high_key->fmr_device)
841 return false;
842 if (low_key->fmr_device < high_key->fmr_device)
843 return true;
844
845 if (low_key->fmr_physical > high_key->fmr_physical)
846 return false;
847 if (low_key->fmr_physical < high_key->fmr_physical)
848 return true;
849
850 if (low_key->fmr_owner > high_key->fmr_owner)
851 return false;
852 if (low_key->fmr_owner < high_key->fmr_owner)
853 return true;
854
855 if (low_key->fmr_offset > high_key->fmr_offset)
856 return false;
857 if (low_key->fmr_offset < high_key->fmr_offset)
858 return true;
859
860 return false;
861 }
862
863 /*
864 * There are only two devices if we didn't configure RT devices at build time.
865 */
866 #ifdef CONFIG_XFS_RT
867 #define XFS_GETFSMAP_DEVS 3
868 #else
869 #define XFS_GETFSMAP_DEVS 2
870 #endif /* CONFIG_XFS_RT */
871
872 /*
873 * Get filesystem's extents as described in head, and format for output. Fills
874 * in the supplied records array until there are no more reverse mappings to
875 * return or head.fmh_entries == head.fmh_count. In the second case, this
876 * function returns -ECANCELED to indicate that more records would have been
877 * returned.
878 *
879 * Key to Confusion
880 * ----------------
881 * There are multiple levels of keys and counters at work here:
882 * xfs_fsmap_head.fmh_keys -- low and high fsmap keys passed in;
883 * these reflect fs-wide sector addrs.
884 * dkeys -- fmh_keys used to query each device;
885 * these are fmh_keys but w/ the low key
886 * bumped up by fmr_length.
887 * xfs_getfsmap_info.next_daddr -- next disk addr we expect to see; this
888 * is how we detect gaps in the fsmap
889 records and report them.
890 * xfs_getfsmap_info.low/high -- per-AG low/high keys computed from
891 * dkeys; used to query the metadata.
892 */
893 int
894 xfs_getfsmap(
895 struct xfs_mount *mp,
896 struct xfs_fsmap_head *head,
897 struct fsmap *fsmap_recs)
898 {
899 struct xfs_trans *tp = NULL;
900 struct xfs_fsmap dkeys[2]; /* per-dev keys */
901 struct xfs_getfsmap_dev handlers[XFS_GETFSMAP_DEVS];
902 struct xfs_getfsmap_info info = { NULL };
903 bool use_rmap;
904 int i;
905 int error = 0;
906
907 if (head->fmh_iflags & ~FMH_IF_VALID)
908 return -EINVAL;
909 if (!xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[0]) ||
910 !xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[1]))
911 return -EINVAL;
912 if (!xfs_getfsmap_check_keys(&head->fmh_keys[0], &head->fmh_keys[1]))
913 return -EINVAL;
914
915 use_rmap = xfs_has_rmapbt(mp) &&
916 has_capability_noaudit(current, CAP_SYS_ADMIN);
917 head->fmh_entries = 0;
918
919 /* Set up our device handlers. */
920 memset(handlers, 0, sizeof(handlers));
921 handlers[0].nr_sectors = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
922 handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev);
923 if (use_rmap)
924 handlers[0].fn = xfs_getfsmap_datadev_rmapbt;
925 else
926 handlers[0].fn = xfs_getfsmap_datadev_bnobt;
927 if (mp->m_logdev_targp != mp->m_ddev_targp) {
928 handlers[1].nr_sectors = XFS_FSB_TO_BB(mp,
929 mp->m_sb.sb_logblocks);
930 handlers[1].dev = new_encode_dev(mp->m_logdev_targp->bt_dev);
931 handlers[1].fn = xfs_getfsmap_logdev;
932 }
933 #ifdef CONFIG_XFS_RT
934 if (mp->m_rtdev_targp) {
935 handlers[2].nr_sectors = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
936 handlers[2].dev = new_encode_dev(mp->m_rtdev_targp->bt_dev);
937 handlers[2].fn = xfs_getfsmap_rtdev_rtbitmap;
938 }
939 #endif /* CONFIG_XFS_RT */
940
941 xfs_sort(handlers, XFS_GETFSMAP_DEVS, sizeof(struct xfs_getfsmap_dev),
942 xfs_getfsmap_dev_compare);
943
944 /*
945 * To continue where we left off, we allow userspace to use the
946 * last mapping from a previous call as the low key of the next.
947 * This is identified by a non-zero length in the low key. We
948 * have to increment the low key in this scenario to ensure we
949 * don't return the same mapping again, and instead return the
950 * very next mapping.
951 *
952 * If the low key mapping refers to file data, the same physical
953 * blocks could be mapped to several other files/offsets.
954 * According to rmapbt record ordering, the minimal next
955 * possible record for the block range is the next starting
956 * offset in the same inode. Therefore, each fsmap backend bumps
957 * the file offset to continue the search appropriately. For
958 * all other low key mapping types (attr blocks, metadata), each
959 * fsmap backend bumps the physical offset as there can be no
960 * other mapping for the same physical block range.
961 */
962 dkeys[0] = head->fmh_keys[0];
963 memset(&dkeys[1], 0xFF, sizeof(struct xfs_fsmap));
964
965 info.next_daddr = head->fmh_keys[0].fmr_physical +
966 head->fmh_keys[0].fmr_length;
967 info.end_daddr = XFS_BUF_DADDR_NULL;
968 info.fsmap_recs = fsmap_recs;
969 info.head = head;
970
971 /* For each device we support... */
972 for (i = 0; i < XFS_GETFSMAP_DEVS; i++) {
973 /* Is this device within the range the user asked for? */
974 if (!handlers[i].fn)
975 continue;
976 if (head->fmh_keys[0].fmr_device > handlers[i].dev)
977 continue;
978 if (head->fmh_keys[1].fmr_device < handlers[i].dev)
979 break;
980
981 /*
982 * If this device number matches the high key, we have
983 * to pass the high key to the handler to limit the
984 * query results. If the device number exceeds the
985 * low key, zero out the low key so that we get
986 * everything from the beginning.
987 */
988 if (handlers[i].dev == head->fmh_keys[1].fmr_device) {
989 dkeys[1] = head->fmh_keys[1];
990 info.end_daddr = min(handlers[i].nr_sectors - 1,
991 dkeys[1].fmr_physical);
992 }
993 if (handlers[i].dev > head->fmh_keys[0].fmr_device)
994 memset(&dkeys[0], 0, sizeof(struct xfs_fsmap));
995
996 /*
997 * Grab an empty transaction so that we can use its recursive
998 * buffer locking abilities to detect cycles in the rmapbt
999 * without deadlocking.
1000 */
1001 error = xfs_trans_alloc_empty(mp, &tp);
1002 if (error)
1003 break;
1004
1005 info.dev = handlers[i].dev;
1006 info.last = false;
1007 info.pag = NULL;
1008 info.low_daddr = XFS_BUF_DADDR_NULL;
1009 info.low.rm_blockcount = 0;
1010 error = handlers[i].fn(tp, dkeys, &info);
1011 if (error)
1012 break;
1013 xfs_trans_cancel(tp);
1014 tp = NULL;
1015 info.next_daddr = 0;
1016 }
1017
1018 if (tp)
1019 xfs_trans_cancel(tp);
1020 head->fmh_oflags = FMH_OF_DEV_T;
1021 return error;
1022 }
1023
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