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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#include "xfs_rtgroup.h"
29
30/* Convert an xfs_fsmap to an fsmap. */
31static void
32xfs_fsmap_from_internal(
33 struct fsmap *dest,
34 struct xfs_fsmap *src)
35{
36 dest->fmr_device = src->fmr_device;
37 dest->fmr_flags = src->fmr_flags;
38 dest->fmr_physical = BBTOB(src->fmr_physical);
39 dest->fmr_owner = src->fmr_owner;
40 dest->fmr_offset = BBTOB(src->fmr_offset);
41 dest->fmr_length = BBTOB(src->fmr_length);
42 dest->fmr_reserved[0] = 0;
43 dest->fmr_reserved[1] = 0;
44 dest->fmr_reserved[2] = 0;
45}
46
47/* Convert an fsmap to an xfs_fsmap. */
48static void
49xfs_fsmap_to_internal(
50 struct xfs_fsmap *dest,
51 struct fsmap *src)
52{
53 dest->fmr_device = src->fmr_device;
54 dest->fmr_flags = src->fmr_flags;
55 dest->fmr_physical = BTOBBT(src->fmr_physical);
56 dest->fmr_owner = src->fmr_owner;
57 dest->fmr_offset = BTOBBT(src->fmr_offset);
58 dest->fmr_length = BTOBBT(src->fmr_length);
59}
60
61/* Convert an fsmap owner into an rmapbt owner. */
62static int
63xfs_fsmap_owner_to_rmap(
64 struct xfs_rmap_irec *dest,
65 const struct xfs_fsmap *src)
66{
67 if (!(src->fmr_flags & FMR_OF_SPECIAL_OWNER)) {
68 dest->rm_owner = src->fmr_owner;
69 return 0;
70 }
71
72 switch (src->fmr_owner) {
73 case 0: /* "lowest owner id possible" */
74 case -1ULL: /* "highest owner id possible" */
75 dest->rm_owner = src->fmr_owner;
76 break;
77 case XFS_FMR_OWN_FREE:
78 dest->rm_owner = XFS_RMAP_OWN_NULL;
79 break;
80 case XFS_FMR_OWN_UNKNOWN:
81 dest->rm_owner = XFS_RMAP_OWN_UNKNOWN;
82 break;
83 case XFS_FMR_OWN_FS:
84 dest->rm_owner = XFS_RMAP_OWN_FS;
85 break;
86 case XFS_FMR_OWN_LOG:
87 dest->rm_owner = XFS_RMAP_OWN_LOG;
88 break;
89 case XFS_FMR_OWN_AG:
90 dest->rm_owner = XFS_RMAP_OWN_AG;
91 break;
92 case XFS_FMR_OWN_INOBT:
93 dest->rm_owner = XFS_RMAP_OWN_INOBT;
94 break;
95 case XFS_FMR_OWN_INODES:
96 dest->rm_owner = XFS_RMAP_OWN_INODES;
97 break;
98 case XFS_FMR_OWN_REFC:
99 dest->rm_owner = XFS_RMAP_OWN_REFC;
100 break;
101 case XFS_FMR_OWN_COW:
102 dest->rm_owner = XFS_RMAP_OWN_COW;
103 break;
104 case XFS_FMR_OWN_DEFECTIVE: /* not implemented */
105 /* fall through */
106 default:
107 return -EINVAL;
108 }
109 return 0;
110}
111
112/* Convert an rmapbt owner into an fsmap owner. */
113static int
114xfs_fsmap_owner_from_frec(
115 struct xfs_fsmap *dest,
116 const struct xfs_fsmap_irec *frec)
117{
118 dest->fmr_flags = 0;
119 if (!XFS_RMAP_NON_INODE_OWNER(frec->owner)) {
120 dest->fmr_owner = frec->owner;
121 return 0;
122 }
123 dest->fmr_flags |= FMR_OF_SPECIAL_OWNER;
124
125 switch (frec->owner) {
126 case XFS_RMAP_OWN_FS:
127 dest->fmr_owner = XFS_FMR_OWN_FS;
128 break;
129 case XFS_RMAP_OWN_LOG:
130 dest->fmr_owner = XFS_FMR_OWN_LOG;
131 break;
132 case XFS_RMAP_OWN_AG:
133 dest->fmr_owner = XFS_FMR_OWN_AG;
134 break;
135 case XFS_RMAP_OWN_INOBT:
136 dest->fmr_owner = XFS_FMR_OWN_INOBT;
137 break;
138 case XFS_RMAP_OWN_INODES:
139 dest->fmr_owner = XFS_FMR_OWN_INODES;
140 break;
141 case XFS_RMAP_OWN_REFC:
142 dest->fmr_owner = XFS_FMR_OWN_REFC;
143 break;
144 case XFS_RMAP_OWN_COW:
145 dest->fmr_owner = XFS_FMR_OWN_COW;
146 break;
147 case XFS_RMAP_OWN_NULL: /* "free" */
148 dest->fmr_owner = XFS_FMR_OWN_FREE;
149 break;
150 default:
151 ASSERT(0);
152 return -EFSCORRUPTED;
153 }
154 return 0;
155}
156
157/* getfsmap query state */
158struct xfs_getfsmap_info {
159 struct xfs_fsmap_head *head;
160 struct fsmap *fsmap_recs; /* mapping records */
161 struct xfs_buf *agf_bp; /* AGF, for refcount queries */
162 struct xfs_group *group; /* group info, if applicable */
163 xfs_daddr_t next_daddr; /* next daddr we expect */
164 /* daddr of low fsmap key when we're using the rtbitmap */
165 xfs_daddr_t low_daddr;
166 /* daddr of high fsmap key, or the last daddr on the device */
167 xfs_daddr_t end_daddr;
168 u64 missing_owner; /* owner of holes */
169 u32 dev; /* device id */
170 /*
171 * Low rmap key for the query. If low.rm_blockcount is nonzero, this
172 * is the second (or later) call to retrieve the recordset in pieces.
173 * xfs_getfsmap_rec_before_start will compare all records retrieved
174 * by the rmapbt query to filter out any records that start before
175 * the last record.
176 */
177 struct xfs_rmap_irec low;
178 struct xfs_rmap_irec high; /* high rmap key */
179 bool last; /* last extent? */
180};
181
182/* Associate a device with a getfsmap handler. */
183struct xfs_getfsmap_dev {
184 u32 dev;
185 int (*fn)(struct xfs_trans *tp,
186 const struct xfs_fsmap *keys,
187 struct xfs_getfsmap_info *info);
188 sector_t nr_sectors;
189};
190
191/* Compare two getfsmap device handlers. */
192static int
193xfs_getfsmap_dev_compare(
194 const void *p1,
195 const void *p2)
196{
197 const struct xfs_getfsmap_dev *d1 = p1;
198 const struct xfs_getfsmap_dev *d2 = p2;
199
200 return d1->dev - d2->dev;
201}
202
203/* Decide if this mapping is shared. */
204STATIC int
205xfs_getfsmap_is_shared(
206 struct xfs_trans *tp,
207 struct xfs_getfsmap_info *info,
208 const struct xfs_fsmap_irec *frec,
209 bool *stat)
210{
211 struct xfs_mount *mp = tp->t_mountp;
212 struct xfs_btree_cur *cur;
213 xfs_agblock_t fbno;
214 xfs_extlen_t flen;
215 int error;
216
217 *stat = false;
218 if (!xfs_has_reflink(mp))
219 return 0;
220 /* rt files will have no perag structure */
221 if (!info->group)
222 return 0;
223
224 /* Are there any shared blocks here? */
225 flen = 0;
226 cur = xfs_refcountbt_init_cursor(mp, tp, info->agf_bp,
227 to_perag(info->group));
228
229 error = xfs_refcount_find_shared(cur, frec->rec_key,
230 XFS_BB_TO_FSBT(mp, frec->len_daddr), &fbno, &flen,
231 false);
232
233 xfs_btree_del_cursor(cur, error);
234 if (error)
235 return error;
236
237 *stat = flen > 0;
238 return 0;
239}
240
241static inline void
242xfs_getfsmap_format(
243 struct xfs_mount *mp,
244 struct xfs_fsmap *xfm,
245 struct xfs_getfsmap_info *info)
246{
247 struct fsmap *rec;
248
249 trace_xfs_getfsmap_mapping(mp, xfm);
250
251 rec = &info->fsmap_recs[info->head->fmh_entries++];
252 xfs_fsmap_from_internal(rec, xfm);
253}
254
255static inline bool
256xfs_getfsmap_frec_before_start(
257 struct xfs_getfsmap_info *info,
258 const struct xfs_fsmap_irec *frec)
259{
260 if (info->low_daddr != XFS_BUF_DADDR_NULL)
261 return frec->start_daddr < info->low_daddr;
262 if (info->low.rm_blockcount) {
263 struct xfs_rmap_irec rec = {
264 .rm_startblock = frec->rec_key,
265 .rm_owner = frec->owner,
266 .rm_flags = frec->rm_flags,
267 };
268
269 return xfs_rmap_compare(&rec, &info->low) < 0;
270 }
271
272 return false;
273}
274
275/*
276 * Format a reverse mapping for getfsmap, having translated rm_startblock
277 * into the appropriate daddr units. Pass in a nonzero @len_daddr if the
278 * length could be larger than rm_blockcount in struct xfs_rmap_irec.
279 */
280STATIC int
281xfs_getfsmap_helper(
282 struct xfs_trans *tp,
283 struct xfs_getfsmap_info *info,
284 const struct xfs_fsmap_irec *frec)
285{
286 struct xfs_fsmap fmr;
287 struct xfs_mount *mp = tp->t_mountp;
288 bool shared;
289 int error = 0;
290
291 if (fatal_signal_pending(current))
292 return -EINTR;
293
294 /*
295 * Filter out records that start before our startpoint, if the
296 * caller requested that.
297 */
298 if (xfs_getfsmap_frec_before_start(info, frec))
299 goto out;
300
301 /* Are we just counting mappings? */
302 if (info->head->fmh_count == 0) {
303 if (info->head->fmh_entries == UINT_MAX)
304 return -ECANCELED;
305
306 if (frec->start_daddr > info->next_daddr)
307 info->head->fmh_entries++;
308
309 if (info->last)
310 return 0;
311
312 info->head->fmh_entries++;
313 goto out;
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 (frec->start_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 = frec->start_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->group ? info->group->xg_gno : NULLAGNUMBER,
343 frec);
344
345 fmr.fmr_device = info->dev;
346 fmr.fmr_physical = frec->start_daddr;
347 error = xfs_fsmap_owner_from_frec(&fmr, frec);
348 if (error)
349 return error;
350 fmr.fmr_offset = XFS_FSB_TO_BB(mp, frec->offset);
351 fmr.fmr_length = frec->len_daddr;
352 if (frec->rm_flags & XFS_RMAP_UNWRITTEN)
353 fmr.fmr_flags |= FMR_OF_PREALLOC;
354 if (frec->rm_flags & XFS_RMAP_ATTR_FORK)
355 fmr.fmr_flags |= FMR_OF_ATTR_FORK;
356 if (frec->rm_flags & XFS_RMAP_BMBT_BLOCK)
357 fmr.fmr_flags |= FMR_OF_EXTENT_MAP;
358 if (fmr.fmr_flags == 0) {
359 error = xfs_getfsmap_is_shared(tp, info, frec, &shared);
360 if (error)
361 return error;
362 if (shared)
363 fmr.fmr_flags |= FMR_OF_SHARED;
364 }
365
366 xfs_getfsmap_format(mp, &fmr, info);
367out:
368 info->next_daddr = max(info->next_daddr,
369 frec->start_daddr + frec->len_daddr);
370 return 0;
371}
372
373static inline int
374xfs_getfsmap_group_helper(
375 struct xfs_getfsmap_info *info,
376 struct xfs_trans *tp,
377 struct xfs_group *xg,
378 xfs_agblock_t startblock,
379 xfs_extlen_t blockcount,
380 struct xfs_fsmap_irec *frec)
381{
382 /*
383 * For an info->last query, we're looking for a gap between the last
384 * mapping emitted and the high key specified by userspace. If the
385 * user's query spans less than 1 fsblock, then info->high and
386 * info->low will have the same rm_startblock, which causes rec_daddr
387 * and next_daddr to be the same. Therefore, use the end_daddr that
388 * we calculated from userspace's high key to synthesize the record.
389 * Note that if the btree query found a mapping, there won't be a gap.
390 */
391 if (info->last)
392 frec->start_daddr = info->end_daddr + 1;
393 else
394 frec->start_daddr = xfs_gbno_to_daddr(xg, startblock);
395
396 frec->len_daddr = XFS_FSB_TO_BB(xg->xg_mount, blockcount);
397 return xfs_getfsmap_helper(tp, info, frec);
398}
399
400/* Transform a rmapbt irec into a fsmap */
401STATIC int
402xfs_getfsmap_rmapbt_helper(
403 struct xfs_btree_cur *cur,
404 const struct xfs_rmap_irec *rec,
405 void *priv)
406{
407 struct xfs_fsmap_irec frec = {
408 .owner = rec->rm_owner,
409 .offset = rec->rm_offset,
410 .rm_flags = rec->rm_flags,
411 .rec_key = rec->rm_startblock,
412 };
413 struct xfs_getfsmap_info *info = priv;
414
415 return xfs_getfsmap_group_helper(info, cur->bc_tp, cur->bc_group,
416 rec->rm_startblock, rec->rm_blockcount, &frec);
417}
418
419/* Transform a bnobt irec into a fsmap */
420STATIC int
421xfs_getfsmap_datadev_bnobt_helper(
422 struct xfs_btree_cur *cur,
423 const struct xfs_alloc_rec_incore *rec,
424 void *priv)
425{
426 struct xfs_fsmap_irec frec = {
427 .owner = XFS_RMAP_OWN_NULL, /* "free" */
428 .rec_key = rec->ar_startblock,
429 };
430 struct xfs_getfsmap_info *info = priv;
431
432 return xfs_getfsmap_group_helper(info, cur->bc_tp, cur->bc_group,
433 rec->ar_startblock, rec->ar_blockcount, &frec);
434}
435
436/* Set rmap flags based on the getfsmap flags */
437static void
438xfs_getfsmap_set_irec_flags(
439 struct xfs_rmap_irec *irec,
440 const struct xfs_fsmap *fmr)
441{
442 irec->rm_flags = 0;
443 if (fmr->fmr_flags & FMR_OF_ATTR_FORK)
444 irec->rm_flags |= XFS_RMAP_ATTR_FORK;
445 if (fmr->fmr_flags & FMR_OF_EXTENT_MAP)
446 irec->rm_flags |= XFS_RMAP_BMBT_BLOCK;
447 if (fmr->fmr_flags & FMR_OF_PREALLOC)
448 irec->rm_flags |= XFS_RMAP_UNWRITTEN;
449}
450
451static inline bool
452rmap_not_shareable(struct xfs_mount *mp, const struct xfs_rmap_irec *r)
453{
454 if (!xfs_has_reflink(mp))
455 return true;
456 if (XFS_RMAP_NON_INODE_OWNER(r->rm_owner))
457 return true;
458 if (r->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK |
459 XFS_RMAP_UNWRITTEN))
460 return true;
461 return false;
462}
463
464/* Execute a getfsmap query against the regular data device. */
465STATIC int
466__xfs_getfsmap_datadev(
467 struct xfs_trans *tp,
468 const struct xfs_fsmap *keys,
469 struct xfs_getfsmap_info *info,
470 int (*query_fn)(struct xfs_trans *,
471 struct xfs_getfsmap_info *,
472 struct xfs_btree_cur **,
473 void *),
474 void *priv)
475{
476 struct xfs_mount *mp = tp->t_mountp;
477 struct xfs_perag *pag = NULL;
478 struct xfs_btree_cur *bt_cur = NULL;
479 xfs_fsblock_t start_fsb;
480 xfs_fsblock_t end_fsb;
481 xfs_agnumber_t start_ag, end_ag;
482 uint64_t eofs;
483 int error = 0;
484
485 eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
486 if (keys[0].fmr_physical >= eofs)
487 return 0;
488 start_fsb = XFS_DADDR_TO_FSB(mp, keys[0].fmr_physical);
489 end_fsb = XFS_DADDR_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical));
490
491 /*
492 * Convert the fsmap low/high keys to AG based keys. Initialize
493 * low to the fsmap low key and max out the high key to the end
494 * of the AG.
495 */
496 info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset);
497 error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]);
498 if (error)
499 return error;
500 info->low.rm_blockcount = XFS_BB_TO_FSBT(mp, keys[0].fmr_length);
501 xfs_getfsmap_set_irec_flags(&info->low, &keys[0]);
502
503 /* Adjust the low key if we are continuing from where we left off. */
504 if (info->low.rm_blockcount == 0) {
505 /* No previous record from which to continue */
506 } else if (rmap_not_shareable(mp, &info->low)) {
507 /* Last record seen was an unshareable extent */
508 info->low.rm_owner = 0;
509 info->low.rm_offset = 0;
510
511 start_fsb += info->low.rm_blockcount;
512 if (XFS_FSB_TO_DADDR(mp, start_fsb) >= eofs)
513 return 0;
514 } else {
515 /* Last record seen was a shareable file data extent */
516 info->low.rm_offset += info->low.rm_blockcount;
517 }
518 info->low.rm_startblock = XFS_FSB_TO_AGBNO(mp, start_fsb);
519
520 info->high.rm_startblock = -1U;
521 info->high.rm_owner = ULLONG_MAX;
522 info->high.rm_offset = ULLONG_MAX;
523 info->high.rm_blockcount = 0;
524 info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS;
525
526 start_ag = XFS_FSB_TO_AGNO(mp, start_fsb);
527 end_ag = XFS_FSB_TO_AGNO(mp, end_fsb);
528
529 while ((pag = xfs_perag_next_range(mp, pag, start_ag, end_ag))) {
530 /*
531 * Set the AG high key from the fsmap high key if this
532 * is the last AG that we're querying.
533 */
534 info->group = pag_group(pag);
535 if (pag_agno(pag) == end_ag) {
536 info->high.rm_startblock = XFS_FSB_TO_AGBNO(mp,
537 end_fsb);
538 info->high.rm_offset = XFS_BB_TO_FSBT(mp,
539 keys[1].fmr_offset);
540 error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]);
541 if (error)
542 break;
543 xfs_getfsmap_set_irec_flags(&info->high, &keys[1]);
544 }
545
546 if (bt_cur) {
547 xfs_btree_del_cursor(bt_cur, XFS_BTREE_NOERROR);
548 bt_cur = NULL;
549 xfs_trans_brelse(tp, info->agf_bp);
550 info->agf_bp = NULL;
551 }
552
553 error = xfs_alloc_read_agf(pag, tp, 0, &info->agf_bp);
554 if (error)
555 break;
556
557 trace_xfs_fsmap_low_group_key(mp, info->dev, pag_agno(pag),
558 &info->low);
559 trace_xfs_fsmap_high_group_key(mp, info->dev, pag_agno(pag),
560 &info->high);
561
562 error = query_fn(tp, info, &bt_cur, priv);
563 if (error)
564 break;
565
566 /*
567 * Set the AG low key to the start of the AG prior to
568 * moving on to the next AG.
569 */
570 if (pag_agno(pag) == start_ag)
571 memset(&info->low, 0, sizeof(info->low));
572
573 /*
574 * If this is the last AG, report any gap at the end of it
575 * before we drop the reference to the perag when the loop
576 * terminates.
577 */
578 if (pag_agno(pag) == end_ag) {
579 info->last = true;
580 error = query_fn(tp, info, &bt_cur, priv);
581 if (error)
582 break;
583 }
584 info->group = NULL;
585 }
586
587 if (bt_cur)
588 xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR :
589 XFS_BTREE_NOERROR);
590 if (info->agf_bp) {
591 xfs_trans_brelse(tp, info->agf_bp);
592 info->agf_bp = NULL;
593 }
594 if (info->group) {
595 xfs_perag_rele(pag);
596 info->group = NULL;
597 } else if (pag) {
598 /* loop termination case */
599 xfs_perag_rele(pag);
600 }
601
602 return error;
603}
604
605/* Actually query the rmap btree. */
606STATIC int
607xfs_getfsmap_datadev_rmapbt_query(
608 struct xfs_trans *tp,
609 struct xfs_getfsmap_info *info,
610 struct xfs_btree_cur **curpp,
611 void *priv)
612{
613 /* Report any gap at the end of the last AG. */
614 if (info->last)
615 return xfs_getfsmap_rmapbt_helper(*curpp, &info->high, info);
616
617 /* Allocate cursor for this AG and query_range it. */
618 *curpp = xfs_rmapbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
619 to_perag(info->group));
620 return xfs_rmap_query_range(*curpp, &info->low, &info->high,
621 xfs_getfsmap_rmapbt_helper, info);
622}
623
624/* Execute a getfsmap query against the regular data device rmapbt. */
625STATIC int
626xfs_getfsmap_datadev_rmapbt(
627 struct xfs_trans *tp,
628 const struct xfs_fsmap *keys,
629 struct xfs_getfsmap_info *info)
630{
631 info->missing_owner = XFS_FMR_OWN_FREE;
632 return __xfs_getfsmap_datadev(tp, keys, info,
633 xfs_getfsmap_datadev_rmapbt_query, NULL);
634}
635
636/* Actually query the bno btree. */
637STATIC int
638xfs_getfsmap_datadev_bnobt_query(
639 struct xfs_trans *tp,
640 struct xfs_getfsmap_info *info,
641 struct xfs_btree_cur **curpp,
642 void *priv)
643{
644 struct xfs_alloc_rec_incore *key = priv;
645
646 /* Report any gap at the end of the last AG. */
647 if (info->last)
648 return xfs_getfsmap_datadev_bnobt_helper(*curpp, &key[1], info);
649
650 /* Allocate cursor for this AG and query_range it. */
651 *curpp = xfs_bnobt_init_cursor(tp->t_mountp, tp, info->agf_bp,
652 to_perag(info->group));
653 key->ar_startblock = info->low.rm_startblock;
654 key[1].ar_startblock = info->high.rm_startblock;
655 return xfs_alloc_query_range(*curpp, key, &key[1],
656 xfs_getfsmap_datadev_bnobt_helper, info);
657}
658
659/* Execute a getfsmap query against the regular data device's bnobt. */
660STATIC int
661xfs_getfsmap_datadev_bnobt(
662 struct xfs_trans *tp,
663 const struct xfs_fsmap *keys,
664 struct xfs_getfsmap_info *info)
665{
666 struct xfs_alloc_rec_incore akeys[2];
667
668 memset(akeys, 0, sizeof(akeys));
669 info->missing_owner = XFS_FMR_OWN_UNKNOWN;
670 return __xfs_getfsmap_datadev(tp, keys, info,
671 xfs_getfsmap_datadev_bnobt_query, &akeys[0]);
672}
673
674/* Execute a getfsmap query against the log device. */
675STATIC int
676xfs_getfsmap_logdev(
677 struct xfs_trans *tp,
678 const struct xfs_fsmap *keys,
679 struct xfs_getfsmap_info *info)
680{
681 struct xfs_fsmap_irec frec = {
682 .start_daddr = 0,
683 .rec_key = 0,
684 .owner = XFS_RMAP_OWN_LOG,
685 };
686 struct xfs_mount *mp = tp->t_mountp;
687 xfs_fsblock_t start_fsb, end_fsb;
688 uint64_t eofs;
689
690 eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
691 if (keys[0].fmr_physical >= eofs)
692 return 0;
693 start_fsb = XFS_BB_TO_FSBT(mp,
694 keys[0].fmr_physical + keys[0].fmr_length);
695 end_fsb = XFS_BB_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical));
696
697 /* Adjust the low key if we are continuing from where we left off. */
698 if (keys[0].fmr_length > 0)
699 info->low_daddr = XFS_FSB_TO_BB(mp, start_fsb);
700
701 trace_xfs_fsmap_low_linear_key(mp, info->dev, start_fsb);
702 trace_xfs_fsmap_high_linear_key(mp, info->dev, end_fsb);
703
704 if (start_fsb > 0)
705 return 0;
706
707 /* Fabricate an rmap entry for the external log device. */
708 frec.len_daddr = XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
709 return xfs_getfsmap_helper(tp, info, &frec);
710}
711
712#ifdef CONFIG_XFS_RT
713/* Transform a rtbitmap "record" into a fsmap */
714STATIC int
715xfs_getfsmap_rtdev_rtbitmap_helper(
716 struct xfs_rtgroup *rtg,
717 struct xfs_trans *tp,
718 const struct xfs_rtalloc_rec *rec,
719 void *priv)
720{
721 struct xfs_fsmap_irec frec = {
722 .owner = XFS_RMAP_OWN_NULL, /* "free" */
723 };
724 struct xfs_mount *mp = rtg_mount(rtg);
725 struct xfs_getfsmap_info *info = priv;
726 xfs_rtblock_t start_rtb =
727 xfs_rtx_to_rtb(rtg, rec->ar_startext);
728 uint64_t rtbcount =
729 xfs_rtbxlen_to_blen(mp, rec->ar_extcount);
730
731 /*
732 * For an info->last query, we're looking for a gap between the last
733 * mapping emitted and the high key specified by userspace. If the
734 * user's query spans less than 1 fsblock, then info->high and
735 * info->low will have the same rm_startblock, which causes rec_daddr
736 * and next_daddr to be the same. Therefore, use the end_daddr that
737 * we calculated from userspace's high key to synthesize the record.
738 * Note that if the btree query found a mapping, there won't be a gap.
739 */
740 if (info->last)
741 frec.start_daddr = info->end_daddr + 1;
742 else
743 frec.start_daddr = xfs_rtb_to_daddr(mp, start_rtb);
744
745 frec.len_daddr = XFS_FSB_TO_BB(mp, rtbcount);
746 return xfs_getfsmap_helper(tp, info, &frec);
747}
748
749/* Execute a getfsmap query against the realtime device rtbitmap. */
750STATIC int
751xfs_getfsmap_rtdev_rtbitmap(
752 struct xfs_trans *tp,
753 const struct xfs_fsmap *keys,
754 struct xfs_getfsmap_info *info)
755{
756 struct xfs_mount *mp = tp->t_mountp;
757 xfs_rtblock_t start_rtbno, end_rtbno;
758 xfs_rtxnum_t start_rtx, end_rtx;
759 xfs_rgnumber_t start_rgno, end_rgno;
760 struct xfs_rtgroup *rtg = NULL;
761 uint64_t eofs;
762 int error;
763
764 eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
765 if (keys[0].fmr_physical >= eofs)
766 return 0;
767
768 info->missing_owner = XFS_FMR_OWN_UNKNOWN;
769
770 /* Adjust the low key if we are continuing from where we left off. */
771 start_rtbno = xfs_daddr_to_rtb(mp,
772 keys[0].fmr_physical + keys[0].fmr_length);
773 if (keys[0].fmr_length > 0) {
774 info->low_daddr = xfs_rtb_to_daddr(mp, start_rtbno);
775 if (info->low_daddr >= eofs)
776 return 0;
777 }
778 start_rtx = xfs_rtb_to_rtx(mp, start_rtbno);
779 start_rgno = xfs_rtb_to_rgno(mp, start_rtbno);
780
781 end_rtbno = xfs_daddr_to_rtb(mp, min(eofs - 1, keys[1].fmr_physical));
782 end_rgno = xfs_rtb_to_rgno(mp, end_rtbno);
783
784 trace_xfs_fsmap_low_linear_key(mp, info->dev, start_rtbno);
785 trace_xfs_fsmap_high_linear_key(mp, info->dev, end_rtbno);
786
787 end_rtx = -1ULL;
788
789 while ((rtg = xfs_rtgroup_next_range(mp, rtg, start_rgno, end_rgno))) {
790 if (rtg_rgno(rtg) == end_rgno)
791 end_rtx = xfs_rtb_to_rtx(mp,
792 end_rtbno + mp->m_sb.sb_rextsize - 1);
793
794 info->group = rtg_group(rtg);
795 xfs_rtgroup_lock(rtg, XFS_RTGLOCK_BITMAP_SHARED);
796 error = xfs_rtalloc_query_range(rtg, tp, start_rtx, end_rtx,
797 xfs_getfsmap_rtdev_rtbitmap_helper, info);
798 if (error)
799 break;
800
801 /*
802 * Report any gaps at the end of the rtbitmap by simulating a
803 * zero-length free extent starting at the rtx after the end
804 * of the query range.
805 */
806 if (rtg_rgno(rtg) == end_rgno) {
807 struct xfs_rtalloc_rec ahigh = {
808 .ar_startext = min(end_rtx + 1,
809 rtg->rtg_extents),
810 };
811
812 info->last = true;
813 error = xfs_getfsmap_rtdev_rtbitmap_helper(rtg, tp,
814 &ahigh, info);
815 if (error)
816 break;
817 }
818
819 xfs_rtgroup_unlock(rtg, XFS_RTGLOCK_BITMAP_SHARED);
820 info->group = NULL;
821 start_rtx = 0;
822 }
823
824 /* loop termination case */
825 if (rtg) {
826 if (info->group) {
827 xfs_rtgroup_unlock(rtg, XFS_RTGLOCK_BITMAP_SHARED);
828 info->group = NULL;
829 }
830 xfs_rtgroup_rele(rtg);
831 }
832
833 return error;
834}
835#endif /* CONFIG_XFS_RT */
836
837/* Do we recognize the device? */
838STATIC bool
839xfs_getfsmap_is_valid_device(
840 struct xfs_mount *mp,
841 struct xfs_fsmap *fm)
842{
843 if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX ||
844 fm->fmr_device == new_encode_dev(mp->m_ddev_targp->bt_dev))
845 return true;
846 if (mp->m_logdev_targp &&
847 fm->fmr_device == new_encode_dev(mp->m_logdev_targp->bt_dev))
848 return true;
849 if (mp->m_rtdev_targp &&
850 fm->fmr_device == new_encode_dev(mp->m_rtdev_targp->bt_dev))
851 return true;
852 return false;
853}
854
855/* Ensure that the low key is less than the high key. */
856STATIC bool
857xfs_getfsmap_check_keys(
858 struct xfs_fsmap *low_key,
859 struct xfs_fsmap *high_key)
860{
861 if (low_key->fmr_flags & (FMR_OF_SPECIAL_OWNER | FMR_OF_EXTENT_MAP)) {
862 if (low_key->fmr_offset)
863 return false;
864 }
865 if (high_key->fmr_flags != -1U &&
866 (high_key->fmr_flags & (FMR_OF_SPECIAL_OWNER |
867 FMR_OF_EXTENT_MAP))) {
868 if (high_key->fmr_offset && high_key->fmr_offset != -1ULL)
869 return false;
870 }
871 if (high_key->fmr_length && high_key->fmr_length != -1ULL)
872 return false;
873
874 if (low_key->fmr_device > high_key->fmr_device)
875 return false;
876 if (low_key->fmr_device < high_key->fmr_device)
877 return true;
878
879 if (low_key->fmr_physical > high_key->fmr_physical)
880 return false;
881 if (low_key->fmr_physical < high_key->fmr_physical)
882 return true;
883
884 if (low_key->fmr_owner > high_key->fmr_owner)
885 return false;
886 if (low_key->fmr_owner < high_key->fmr_owner)
887 return true;
888
889 if (low_key->fmr_offset > high_key->fmr_offset)
890 return false;
891 if (low_key->fmr_offset < high_key->fmr_offset)
892 return true;
893
894 return false;
895}
896
897/*
898 * There are only two devices if we didn't configure RT devices at build time.
899 */
900#ifdef CONFIG_XFS_RT
901#define XFS_GETFSMAP_DEVS 3
902#else
903#define XFS_GETFSMAP_DEVS 2
904#endif /* CONFIG_XFS_RT */
905
906/*
907 * Get filesystem's extents as described in head, and format for output. Fills
908 * in the supplied records array until there are no more reverse mappings to
909 * return or head.fmh_entries == head.fmh_count. In the second case, this
910 * function returns -ECANCELED to indicate that more records would have been
911 * returned.
912 *
913 * Key to Confusion
914 * ----------------
915 * There are multiple levels of keys and counters at work here:
916 * xfs_fsmap_head.fmh_keys -- low and high fsmap keys passed in;
917 * these reflect fs-wide sector addrs.
918 * dkeys -- fmh_keys used to query each device;
919 * these are fmh_keys but w/ the low key
920 * bumped up by fmr_length.
921 * xfs_getfsmap_info.next_daddr -- next disk addr we expect to see; this
922 * is how we detect gaps in the fsmap
923 records and report them.
924 * xfs_getfsmap_info.low/high -- per-AG low/high keys computed from
925 * dkeys; used to query the metadata.
926 */
927STATIC int
928xfs_getfsmap(
929 struct xfs_mount *mp,
930 struct xfs_fsmap_head *head,
931 struct fsmap *fsmap_recs)
932{
933 struct xfs_trans *tp = NULL;
934 struct xfs_fsmap dkeys[2]; /* per-dev keys */
935 struct xfs_getfsmap_dev handlers[XFS_GETFSMAP_DEVS];
936 struct xfs_getfsmap_info info = {
937 .fsmap_recs = fsmap_recs,
938 .head = head,
939 };
940 bool use_rmap;
941 int i;
942 int error = 0;
943
944 if (head->fmh_iflags & ~FMH_IF_VALID)
945 return -EINVAL;
946 if (!xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[0]) ||
947 !xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[1]))
948 return -EINVAL;
949 if (!xfs_getfsmap_check_keys(&head->fmh_keys[0], &head->fmh_keys[1]))
950 return -EINVAL;
951
952 use_rmap = xfs_has_rmapbt(mp) &&
953 has_capability_noaudit(current, CAP_SYS_ADMIN);
954 head->fmh_entries = 0;
955
956 /* Set up our device handlers. */
957 memset(handlers, 0, sizeof(handlers));
958 handlers[0].nr_sectors = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
959 handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev);
960 if (use_rmap)
961 handlers[0].fn = xfs_getfsmap_datadev_rmapbt;
962 else
963 handlers[0].fn = xfs_getfsmap_datadev_bnobt;
964 if (mp->m_logdev_targp != mp->m_ddev_targp) {
965 handlers[1].nr_sectors = XFS_FSB_TO_BB(mp,
966 mp->m_sb.sb_logblocks);
967 handlers[1].dev = new_encode_dev(mp->m_logdev_targp->bt_dev);
968 handlers[1].fn = xfs_getfsmap_logdev;
969 }
970#ifdef CONFIG_XFS_RT
971 if (mp->m_rtdev_targp) {
972 handlers[2].nr_sectors = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
973 handlers[2].dev = new_encode_dev(mp->m_rtdev_targp->bt_dev);
974 handlers[2].fn = xfs_getfsmap_rtdev_rtbitmap;
975 }
976#endif /* CONFIG_XFS_RT */
977
978 xfs_sort(handlers, XFS_GETFSMAP_DEVS, sizeof(struct xfs_getfsmap_dev),
979 xfs_getfsmap_dev_compare);
980
981 /*
982 * To continue where we left off, we allow userspace to use the
983 * last mapping from a previous call as the low key of the next.
984 * This is identified by a non-zero length in the low key. We
985 * have to increment the low key in this scenario to ensure we
986 * don't return the same mapping again, and instead return the
987 * very next mapping.
988 *
989 * If the low key mapping refers to file data, the same physical
990 * blocks could be mapped to several other files/offsets.
991 * According to rmapbt record ordering, the minimal next
992 * possible record for the block range is the next starting
993 * offset in the same inode. Therefore, each fsmap backend bumps
994 * the file offset to continue the search appropriately. For
995 * all other low key mapping types (attr blocks, metadata), each
996 * fsmap backend bumps the physical offset as there can be no
997 * other mapping for the same physical block range.
998 */
999 dkeys[0] = head->fmh_keys[0];
1000 memset(&dkeys[1], 0xFF, sizeof(struct xfs_fsmap));
1001
1002 info.next_daddr = head->fmh_keys[0].fmr_physical +
1003 head->fmh_keys[0].fmr_length;
1004
1005 /* For each device we support... */
1006 for (i = 0; i < XFS_GETFSMAP_DEVS; i++) {
1007 /* Is this device within the range the user asked for? */
1008 if (!handlers[i].fn)
1009 continue;
1010 if (head->fmh_keys[0].fmr_device > handlers[i].dev)
1011 continue;
1012 if (head->fmh_keys[1].fmr_device < handlers[i].dev)
1013 break;
1014
1015 /*
1016 * If this device number matches the high key, we have to pass
1017 * the high key to the handler to limit the query results, and
1018 * set the end_daddr so that we can synthesize records at the
1019 * end of the query range or device.
1020 */
1021 if (handlers[i].dev == head->fmh_keys[1].fmr_device) {
1022 dkeys[1] = head->fmh_keys[1];
1023 info.end_daddr = min(handlers[i].nr_sectors - 1,
1024 dkeys[1].fmr_physical);
1025 } else {
1026 info.end_daddr = handlers[i].nr_sectors - 1;
1027 }
1028
1029 /*
1030 * If the device number exceeds the low key, zero out the low
1031 * key so that we get everything from the beginning.
1032 */
1033 if (handlers[i].dev > head->fmh_keys[0].fmr_device)
1034 memset(&dkeys[0], 0, sizeof(struct xfs_fsmap));
1035
1036 /*
1037 * Grab an empty transaction so that we can use its recursive
1038 * buffer locking abilities to detect cycles in the rmapbt
1039 * without deadlocking.
1040 */
1041 error = xfs_trans_alloc_empty(mp, &tp);
1042 if (error)
1043 break;
1044
1045 info.dev = handlers[i].dev;
1046 info.last = false;
1047 info.group = NULL;
1048 info.low_daddr = XFS_BUF_DADDR_NULL;
1049 info.low.rm_blockcount = 0;
1050 error = handlers[i].fn(tp, dkeys, &info);
1051 if (error)
1052 break;
1053 xfs_trans_cancel(tp);
1054 tp = NULL;
1055 info.next_daddr = 0;
1056 }
1057
1058 if (tp)
1059 xfs_trans_cancel(tp);
1060 head->fmh_oflags = FMH_OF_DEV_T;
1061 return error;
1062}
1063
1064int
1065xfs_ioc_getfsmap(
1066 struct xfs_inode *ip,
1067 struct fsmap_head __user *arg)
1068{
1069 struct xfs_fsmap_head xhead = {0};
1070 struct fsmap_head head;
1071 struct fsmap *recs;
1072 unsigned int count;
1073 __u32 last_flags = 0;
1074 bool done = false;
1075 int error;
1076
1077 if (copy_from_user(&head, arg, sizeof(struct fsmap_head)))
1078 return -EFAULT;
1079 if (memchr_inv(head.fmh_reserved, 0, sizeof(head.fmh_reserved)) ||
1080 memchr_inv(head.fmh_keys[0].fmr_reserved, 0,
1081 sizeof(head.fmh_keys[0].fmr_reserved)) ||
1082 memchr_inv(head.fmh_keys[1].fmr_reserved, 0,
1083 sizeof(head.fmh_keys[1].fmr_reserved)))
1084 return -EINVAL;
1085
1086 /*
1087 * Use an internal memory buffer so that we don't have to copy fsmap
1088 * data to userspace while holding locks. Start by trying to allocate
1089 * up to 128k for the buffer, but fall back to a single page if needed.
1090 */
1091 count = min_t(unsigned int, head.fmh_count,
1092 131072 / sizeof(struct fsmap));
1093 recs = kvcalloc(count, sizeof(struct fsmap), GFP_KERNEL);
1094 if (!recs) {
1095 count = min_t(unsigned int, head.fmh_count,
1096 PAGE_SIZE / sizeof(struct fsmap));
1097 recs = kvcalloc(count, sizeof(struct fsmap), GFP_KERNEL);
1098 if (!recs)
1099 return -ENOMEM;
1100 }
1101
1102 xhead.fmh_iflags = head.fmh_iflags;
1103 xfs_fsmap_to_internal(&xhead.fmh_keys[0], &head.fmh_keys[0]);
1104 xfs_fsmap_to_internal(&xhead.fmh_keys[1], &head.fmh_keys[1]);
1105
1106 trace_xfs_getfsmap_low_key(ip->i_mount, &xhead.fmh_keys[0]);
1107 trace_xfs_getfsmap_high_key(ip->i_mount, &xhead.fmh_keys[1]);
1108
1109 head.fmh_entries = 0;
1110 do {
1111 struct fsmap __user *user_recs;
1112 struct fsmap *last_rec;
1113
1114 user_recs = &arg->fmh_recs[head.fmh_entries];
1115 xhead.fmh_entries = 0;
1116 xhead.fmh_count = min_t(unsigned int, count,
1117 head.fmh_count - head.fmh_entries);
1118
1119 /* Run query, record how many entries we got. */
1120 error = xfs_getfsmap(ip->i_mount, &xhead, recs);
1121 switch (error) {
1122 case 0:
1123 /*
1124 * There are no more records in the result set. Copy
1125 * whatever we got to userspace and break out.
1126 */
1127 done = true;
1128 break;
1129 case -ECANCELED:
1130 /*
1131 * The internal memory buffer is full. Copy whatever
1132 * records we got to userspace and go again if we have
1133 * not yet filled the userspace buffer.
1134 */
1135 error = 0;
1136 break;
1137 default:
1138 goto out_free;
1139 }
1140 head.fmh_entries += xhead.fmh_entries;
1141 head.fmh_oflags = xhead.fmh_oflags;
1142
1143 /*
1144 * If the caller wanted a record count or there aren't any
1145 * new records to return, we're done.
1146 */
1147 if (head.fmh_count == 0 || xhead.fmh_entries == 0)
1148 break;
1149
1150 /* Copy all the records we got out to userspace. */
1151 if (copy_to_user(user_recs, recs,
1152 xhead.fmh_entries * sizeof(struct fsmap))) {
1153 error = -EFAULT;
1154 goto out_free;
1155 }
1156
1157 /* Remember the last record flags we copied to userspace. */
1158 last_rec = &recs[xhead.fmh_entries - 1];
1159 last_flags = last_rec->fmr_flags;
1160
1161 /* Set up the low key for the next iteration. */
1162 xfs_fsmap_to_internal(&xhead.fmh_keys[0], last_rec);
1163 trace_xfs_getfsmap_low_key(ip->i_mount, &xhead.fmh_keys[0]);
1164 } while (!done && head.fmh_entries < head.fmh_count);
1165
1166 /*
1167 * If there are no more records in the query result set and we're not
1168 * in counting mode, mark the last record returned with the LAST flag.
1169 */
1170 if (done && head.fmh_count > 0 && head.fmh_entries > 0) {
1171 struct fsmap __user *user_rec;
1172
1173 last_flags |= FMR_OF_LAST;
1174 user_rec = &arg->fmh_recs[head.fmh_entries - 1];
1175
1176 if (copy_to_user(&user_rec->fmr_flags, &last_flags,
1177 sizeof(last_flags))) {
1178 error = -EFAULT;
1179 goto out_free;
1180 }
1181 }
1182
1183 /* copy back header */
1184 if (copy_to_user(arg, &head, sizeof(struct fsmap_head))) {
1185 error = -EFAULT;
1186 goto out_free;
1187 }
1188
1189out_free:
1190 kvfree(recs);
1191 return error;
1192}