fs/xfs/xfs_fsmap.c

   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_rtalloc.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 = 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. */
 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         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. */
 180 struct 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. */
 188 static int
 189 xfs_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. */
 200 STATIC int
 201 xfs_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
 235 static inline void
 236 xfs_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
 249 static inline bool
 250 xfs_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  */
 267 STATIC int
 268 xfs_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);
 366 out:
 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 */
 374 STATIC int
 375 xfs_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 */
 392 STATIC int
 393 xfs_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 */
 416 static void
 417 xfs_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. */
 431 STATIC int
 432 xfs_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 */
 474 STATIC int
 475 xfs_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 = rec->ar_startext * mp->m_sb.sb_rextsize;
 487         rec_daddr = XFS_FSB_TO_BB(mp, rtbno);
 488         irec.rm_startblock = rtbno;
 489
 490         rtbno = rec->ar_extcount * mp->m_sb.sb_rextsize;
 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. */
 502 STATIC int
 503 xfs_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, mp->m_sb.sb_rextents * mp->m_sb.sb_rextsize);
 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 = start_rtb;
 543         ahigh.ar_startext = end_rtb;
 544         do_div(alow.ar_startext, mp->m_sb.sb_rextsize);
 545         if (do_div(ahigh.ar_startext, mp->m_sb.sb_rextsize))
 546                 ahigh.ar_startext++;
 547         error = xfs_rtalloc_query_range(mp, tp, &alow, &ahigh,
 548                         xfs_getfsmap_rtdev_rtbitmap_helper, info);
 549         if (error)
 550                 goto err;
 551
 552         /*
 553          * Report any gaps at the end of the rtbitmap by simulating a null
 554          * rmap starting at the block after the end of the query range.
 555          */
 556         info->last = true;
 557         ahigh.ar_startext = min(mp->m_sb.sb_rextents, ahigh.ar_startext);
 558
 559         error = xfs_getfsmap_rtdev_rtbitmap_helper(mp, tp, &ahigh, info);
 560         if (error)
 561                 goto err;
 562 err:
 563         xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
 564         return error;
 565 }
 566 #endif /* CONFIG_XFS_RT */
 567
 568 static inline bool
 569 rmap_not_shareable(struct xfs_mount *mp, const struct xfs_rmap_irec *r)
 570 {
 571         if (!xfs_has_reflink(mp))
 572                 return true;
 573         if (XFS_RMAP_NON_INODE_OWNER(r->rm_owner))
 574                 return true;
 575         if (r->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK |
 576                            XFS_RMAP_UNWRITTEN))
 577                 return true;
 578         return false;
 579 }
 580
 581 /* Execute a getfsmap query against the regular data device. */
 582 STATIC int
 583 __xfs_getfsmap_datadev(
 584         struct xfs_trans                *tp,
 585         const struct xfs_fsmap          *keys,
 586         struct xfs_getfsmap_info        *info,
 587         int                             (*query_fn)(struct xfs_trans *,
 588                                                     struct xfs_getfsmap_info *,
 589                                                     struct xfs_btree_cur **,
 590                                                     void *),
 591         void                            *priv)
 592 {
 593         struct xfs_mount                *mp = tp->t_mountp;
 594         struct xfs_perag                *pag;
 595         struct xfs_btree_cur            *bt_cur = NULL;
 596         xfs_fsblock_t                   start_fsb;
 597         xfs_fsblock_t                   end_fsb;
 598         xfs_agnumber_t                  start_ag;
 599         xfs_agnumber_t                  end_ag;
 600         uint64_t                        eofs;
 601         int                             error = 0;
 602
 603         eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
 604         if (keys[0].fmr_physical >= eofs)
 605                 return 0;
 606         start_fsb = XFS_DADDR_TO_FSB(mp, keys[0].fmr_physical);
 607         end_fsb = XFS_DADDR_TO_FSB(mp, min(eofs - 1, keys[1].fmr_physical));
 608
 609         /*
 610          * Convert the fsmap low/high keys to AG based keys.  Initialize
 611          * low to the fsmap low key and max out the high key to the end
 612          * of the AG.
 613          */
 614         info->low.rm_offset = XFS_BB_TO_FSBT(mp, keys[0].fmr_offset);
 615         error = xfs_fsmap_owner_to_rmap(&info->low, &keys[0]);
 616         if (error)
 617                 return error;
 618         info->low.rm_blockcount = XFS_BB_TO_FSBT(mp, keys[0].fmr_length);
 619         xfs_getfsmap_set_irec_flags(&info->low, &keys[0]);
 620
 621         /* Adjust the low key if we are continuing from where we left off. */
 622         if (info->low.rm_blockcount == 0) {
 623                 /* No previous record from which to continue */
 624         } else if (rmap_not_shareable(mp, &info->low)) {
 625                 /* Last record seen was an unshareable extent */
 626                 info->low.rm_owner = 0;
 627                 info->low.rm_offset = 0;
 628
 629                 start_fsb += info->low.rm_blockcount;
 630                 if (XFS_FSB_TO_DADDR(mp, start_fsb) >= eofs)
 631                         return 0;
 632         } else {
 633                 /* Last record seen was a shareable file data extent */
 634                 info->low.rm_offset += info->low.rm_blockcount;
 635         }
 636         info->low.rm_startblock = XFS_FSB_TO_AGBNO(mp, start_fsb);
 637
 638         info->high.rm_startblock = -1U;
 639         info->high.rm_owner = ULLONG_MAX;
 640         info->high.rm_offset = ULLONG_MAX;
 641         info->high.rm_blockcount = 0;
 642         info->high.rm_flags = XFS_RMAP_KEY_FLAGS | XFS_RMAP_REC_FLAGS;
 643
 644         start_ag = XFS_FSB_TO_AGNO(mp, start_fsb);
 645         end_ag = XFS_FSB_TO_AGNO(mp, end_fsb);
 646
 647         for_each_perag_range(mp, start_ag, end_ag, pag) {
 648                 /*
 649                  * Set the AG high key from the fsmap high key if this
 650                  * is the last AG that we're querying.
 651                  */
 652                 info->pag = pag;
 653                 if (pag->pag_agno == end_ag) {
 654                         info->high.rm_startblock = XFS_FSB_TO_AGBNO(mp,
 655                                         end_fsb);
 656                         info->high.rm_offset = XFS_BB_TO_FSBT(mp,
 657                                         keys[1].fmr_offset);
 658                         error = xfs_fsmap_owner_to_rmap(&info->high, &keys[1]);
 659                         if (error)
 660                                 break;
 661                         xfs_getfsmap_set_irec_flags(&info->high, &keys[1]);
 662                 }
 663
 664                 if (bt_cur) {
 665                         xfs_btree_del_cursor(bt_cur, XFS_BTREE_NOERROR);
 666                         bt_cur = NULL;
 667                         xfs_trans_brelse(tp, info->agf_bp);
 668                         info->agf_bp = NULL;
 669                 }
 670
 671                 error = xfs_alloc_read_agf(pag, tp, 0, &info->agf_bp);
 672                 if (error)
 673                         break;
 674
 675                 trace_xfs_fsmap_low_key(mp, info->dev, pag->pag_agno,
 676                                 &info->low);
 677                 trace_xfs_fsmap_high_key(mp, info->dev, pag->pag_agno,
 678                                 &info->high);
 679
 680                 error = query_fn(tp, info, &bt_cur, priv);
 681                 if (error)
 682                         break;
 683
 684                 /*
 685                  * Set the AG low key to the start of the AG prior to
 686                  * moving on to the next AG.
 687                  */
 688                 if (pag->pag_agno == start_ag)
 689                         memset(&info->low, 0, sizeof(info->low));
 690
 691                 /*
 692                  * If this is the last AG, report any gap at the end of it
 693                  * before we drop the reference to the perag when the loop
 694                  * terminates.
 695                  */
 696                 if (pag->pag_agno == end_ag) {
 697                         info->last = true;
 698                         error = query_fn(tp, info, &bt_cur, priv);
 699                         if (error)
 700                                 break;
 701                 }
 702                 info->pag = NULL;
 703         }
 704
 705         if (bt_cur)
 706                 xfs_btree_del_cursor(bt_cur, error < 0 ? XFS_BTREE_ERROR :
 707                                                          XFS_BTREE_NOERROR);
 708         if (info->agf_bp) {
 709                 xfs_trans_brelse(tp, info->agf_bp);
 710                 info->agf_bp = NULL;
 711         }
 712         if (info->pag) {
 713                 xfs_perag_rele(info->pag);
 714                 info->pag = NULL;
 715         } else if (pag) {
 716                 /* loop termination case */
 717                 xfs_perag_rele(pag);
 718         }
 719
 720         return error;
 721 }
 722
 723 /* Actually query the rmap btree. */
 724 STATIC int
 725 xfs_getfsmap_datadev_rmapbt_query(
 726         struct xfs_trans                *tp,
 727         struct xfs_getfsmap_info        *info,
 728         struct xfs_btree_cur            **curpp,
 729         void                            *priv)
 730 {
 731         /* Report any gap at the end of the last AG. */
 732         if (info->last)
 733                 return xfs_getfsmap_datadev_helper(*curpp, &info->high, info);
 734
 735         /* Allocate cursor for this AG and query_range it. */
 736         *curpp = xfs_rmapbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
 737                         info->pag);
 738         return xfs_rmap_query_range(*curpp, &info->low, &info->high,
 739                         xfs_getfsmap_datadev_helper, info);
 740 }
 741
 742 /* Execute a getfsmap query against the regular data device rmapbt. */
 743 STATIC int
 744 xfs_getfsmap_datadev_rmapbt(
 745         struct xfs_trans                *tp,
 746         const struct xfs_fsmap          *keys,
 747         struct xfs_getfsmap_info        *info)
 748 {
 749         info->missing_owner = XFS_FMR_OWN_FREE;
 750         return __xfs_getfsmap_datadev(tp, keys, info,
 751                         xfs_getfsmap_datadev_rmapbt_query, NULL);
 752 }
 753
 754 /* Actually query the bno btree. */
 755 STATIC int
 756 xfs_getfsmap_datadev_bnobt_query(
 757         struct xfs_trans                *tp,
 758         struct xfs_getfsmap_info        *info,
 759         struct xfs_btree_cur            **curpp,
 760         void                            *priv)
 761 {
 762         struct xfs_alloc_rec_incore     *key = priv;
 763
 764         /* Report any gap at the end of the last AG. */
 765         if (info->last)
 766                 return xfs_getfsmap_datadev_bnobt_helper(*curpp, &key[1], info);
 767
 768         /* Allocate cursor for this AG and query_range it. */
 769         *curpp = xfs_allocbt_init_cursor(tp->t_mountp, tp, info->agf_bp,
 770                         info->pag, XFS_BTNUM_BNO);
 771         key->ar_startblock = info->low.rm_startblock;
 772         key[1].ar_startblock = info->high.rm_startblock;
 773         return xfs_alloc_query_range(*curpp, key, &key[1],
 774                         xfs_getfsmap_datadev_bnobt_helper, info);
 775 }
 776
 777 /* Execute a getfsmap query against the regular data device's bnobt. */
 778 STATIC int
 779 xfs_getfsmap_datadev_bnobt(
 780         struct xfs_trans                *tp,
 781         const struct xfs_fsmap          *keys,
 782         struct xfs_getfsmap_info        *info)
 783 {
 784         struct xfs_alloc_rec_incore     akeys[2];
 785
 786         memset(akeys, 0, sizeof(akeys));
 787         info->missing_owner = XFS_FMR_OWN_UNKNOWN;
 788         return __xfs_getfsmap_datadev(tp, keys, info,
 789                         xfs_getfsmap_datadev_bnobt_query, &akeys[0]);
 790 }
 791
 792 /* Do we recognize the device? */
 793 STATIC bool
 794 xfs_getfsmap_is_valid_device(
 795         struct xfs_mount        *mp,
 796         struct xfs_fsmap        *fm)
 797 {
 798         if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX ||
 799             fm->fmr_device == new_encode_dev(mp->m_ddev_targp->bt_dev))
 800                 return true;
 801         if (mp->m_logdev_targp &&
 802             fm->fmr_device == new_encode_dev(mp->m_logdev_targp->bt_dev))
 803                 return true;
 804         if (mp->m_rtdev_targp &&
 805             fm->fmr_device == new_encode_dev(mp->m_rtdev_targp->bt_dev))
 806                 return true;
 807         return false;
 808 }
 809
 810 /* Ensure that the low key is less than the high key. */
 811 STATIC bool
 812 xfs_getfsmap_check_keys(
 813         struct xfs_fsmap                *low_key,
 814         struct xfs_fsmap                *high_key)
 815 {
 816         if (low_key->fmr_flags & (FMR_OF_SPECIAL_OWNER | FMR_OF_EXTENT_MAP)) {
 817                 if (low_key->fmr_offset)
 818                         return false;
 819         }
 820         if (high_key->fmr_flags != -1U &&
 821             (high_key->fmr_flags & (FMR_OF_SPECIAL_OWNER |
 822                                     FMR_OF_EXTENT_MAP))) {
 823                 if (high_key->fmr_offset && high_key->fmr_offset != -1ULL)
 824                         return false;
 825         }
 826         if (high_key->fmr_length && high_key->fmr_length != -1ULL)
 827                 return false;
 828
 829         if (low_key->fmr_device > high_key->fmr_device)
 830                 return false;
 831         if (low_key->fmr_device < high_key->fmr_device)
 832                 return true;
 833
 834         if (low_key->fmr_physical > high_key->fmr_physical)
 835                 return false;
 836         if (low_key->fmr_physical < high_key->fmr_physical)
 837                 return true;
 838
 839         if (low_key->fmr_owner > high_key->fmr_owner)
 840                 return false;
 841         if (low_key->fmr_owner < high_key->fmr_owner)
 842                 return true;
 843
 844         if (low_key->fmr_offset > high_key->fmr_offset)
 845                 return false;
 846         if (low_key->fmr_offset < high_key->fmr_offset)
 847                 return true;
 848
 849         return false;
 850 }
 851
 852 /*
 853  * There are only two devices if we didn't configure RT devices at build time.
 854  */
 855 #ifdef CONFIG_XFS_RT
 856 #define XFS_GETFSMAP_DEVS       3
 857 #else
 858 #define XFS_GETFSMAP_DEVS       2
 859 #endif /* CONFIG_XFS_RT */
 860
 861 /*
 862  * Get filesystem's extents as described in head, and format for output. Fills
 863  * in the supplied records array until there are no more reverse mappings to
 864  * return or head.fmh_entries == head.fmh_count.  In the second case, this
 865  * function returns -ECANCELED to indicate that more records would have been
 866  * returned.
 867  *
 868  * Key to Confusion
 869  * ----------------
 870  * There are multiple levels of keys and counters at work here:
 871  * xfs_fsmap_head.fmh_keys      -- low and high fsmap keys passed in;
 872  *                                 these reflect fs-wide sector addrs.
 873  * dkeys                        -- fmh_keys used to query each device;
 874  *                                 these are fmh_keys but w/ the low key
 875  *                                 bumped up by fmr_length.
 876  * xfs_getfsmap_info.next_daddr -- next disk addr we expect to see; this
 877  *                                 is how we detect gaps in the fsmap
 878                                    records and report them.
 879  * xfs_getfsmap_info.low/high   -- per-AG low/high keys computed from
 880  *                                 dkeys; used to query the metadata.
 881  */
 882 int
 883 xfs_getfsmap(
 884         struct xfs_mount                *mp,
 885         struct xfs_fsmap_head           *head,
 886         struct fsmap                    *fsmap_recs)
 887 {
 888         struct xfs_trans                *tp = NULL;
 889         struct xfs_fsmap                dkeys[2];       /* per-dev keys */
 890         struct xfs_getfsmap_dev         handlers[XFS_GETFSMAP_DEVS];
 891         struct xfs_getfsmap_info        info = { NULL };
 892         bool                            use_rmap;
 893         int                             i;
 894         int                             error = 0;
 895
 896         if (head->fmh_iflags & ~FMH_IF_VALID)
 897                 return -EINVAL;
 898         if (!xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[0]) ||
 899             !xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[1]))
 900                 return -EINVAL;
 901         if (!xfs_getfsmap_check_keys(&head->fmh_keys[0], &head->fmh_keys[1]))
 902                 return -EINVAL;
 903
 904         use_rmap = xfs_has_rmapbt(mp) &&
 905                    has_capability_noaudit(current, CAP_SYS_ADMIN);
 906         head->fmh_entries = 0;
 907
 908         /* Set up our device handlers. */
 909         memset(handlers, 0, sizeof(handlers));
 910         handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev);
 911         if (use_rmap)
 912                 handlers[0].fn = xfs_getfsmap_datadev_rmapbt;
 913         else
 914                 handlers[0].fn = xfs_getfsmap_datadev_bnobt;
 915         if (mp->m_logdev_targp != mp->m_ddev_targp) {
 916                 handlers[1].dev = new_encode_dev(mp->m_logdev_targp->bt_dev);
 917                 handlers[1].fn = xfs_getfsmap_logdev;
 918         }
 919 #ifdef CONFIG_XFS_RT
 920         if (mp->m_rtdev_targp) {
 921                 handlers[2].dev = new_encode_dev(mp->m_rtdev_targp->bt_dev);
 922                 handlers[2].fn = xfs_getfsmap_rtdev_rtbitmap;
 923         }
 924 #endif /* CONFIG_XFS_RT */
 925
 926         xfs_sort(handlers, XFS_GETFSMAP_DEVS, sizeof(struct xfs_getfsmap_dev),
 927                         xfs_getfsmap_dev_compare);
 928
 929         /*
 930          * To continue where we left off, we allow userspace to use the
 931          * last mapping from a previous call as the low key of the next.
 932          * This is identified by a non-zero length in the low key. We
 933          * have to increment the low key in this scenario to ensure we
 934          * don't return the same mapping again, and instead return the
 935          * very next mapping.
 936          *
 937          * If the low key mapping refers to file data, the same physical
 938          * blocks could be mapped to several other files/offsets.
 939          * According to rmapbt record ordering, the minimal next
 940          * possible record for the block range is the next starting
 941          * offset in the same inode. Therefore, each fsmap backend bumps
 942          * the file offset to continue the search appropriately.  For
 943          * all other low key mapping types (attr blocks, metadata), each
 944          * fsmap backend bumps the physical offset as there can be no
 945          * other mapping for the same physical block range.
 946          */
 947         dkeys[0] = head->fmh_keys[0];
 948         memset(&dkeys[1], 0xFF, sizeof(struct xfs_fsmap));
 949
 950         info.next_daddr = head->fmh_keys[0].fmr_physical +
 951                           head->fmh_keys[0].fmr_length;
 952         info.fsmap_recs = fsmap_recs;
 953         info.head = head;
 954
 955         /* For each device we support... */
 956         for (i = 0; i < XFS_GETFSMAP_DEVS; i++) {
 957                 /* Is this device within the range the user asked for? */
 958                 if (!handlers[i].fn)
 959                         continue;
 960                 if (head->fmh_keys[0].fmr_device > handlers[i].dev)
 961                         continue;
 962                 if (head->fmh_keys[1].fmr_device < handlers[i].dev)
 963                         break;
 964
 965                 /*
 966                  * If this device number matches the high key, we have
 967                  * to pass the high key to the handler to limit the
 968                  * query results.  If the device number exceeds the
 969                  * low key, zero out the low key so that we get
 970                  * everything from the beginning.
 971                  */
 972                 if (handlers[i].dev == head->fmh_keys[1].fmr_device)
 973                         dkeys[1] = head->fmh_keys[1];
 974                 if (handlers[i].dev > head->fmh_keys[0].fmr_device)
 975                         memset(&dkeys[0], 0, sizeof(struct xfs_fsmap));
 976
 977                 /*
 978                  * Grab an empty transaction so that we can use its recursive
 979                  * buffer locking abilities to detect cycles in the rmapbt
 980                  * without deadlocking.
 981                  */
 982                 error = xfs_trans_alloc_empty(mp, &tp);
 983                 if (error)
 984                         break;
 985
 986                 info.dev = handlers[i].dev;
 987                 info.last = false;
 988                 info.pag = NULL;
 989                 info.low_daddr = -1ULL;
 990                 info.low.rm_blockcount = 0;
 991                 error = handlers[i].fn(tp, dkeys, &info);
 992                 if (error)
 993                         break;
 994                 xfs_trans_cancel(tp);
 995                 tp = NULL;
 996                 info.next_daddr = 0;
 997         }
 998
 999         if (tp)
1000                 xfs_trans_cancel(tp);
1001         head->fmh_oflags = FMH_OF_DEV_T;
1002         return error;
1003 }