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