fs/xfs/libxfs/xfs_sb.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_shared.h"
  21 #include "xfs_format.h"
  22 #include "xfs_log_format.h"
  23 #include "xfs_trans_resv.h"
  24 #include "xfs_bit.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_mount.h"
  27 #include "xfs_inode.h"
  28 #include "xfs_ialloc.h"
  29 #include "xfs_alloc.h"
  30 #include "xfs_error.h"
  31 #include "xfs_trace.h"
  32 #include "xfs_cksum.h"
  33 #include "xfs_trans.h"
  34 #include "xfs_buf_item.h"
  35 #include "xfs_bmap_btree.h"
  36 #include "xfs_alloc_btree.h"
  37 #include "xfs_ialloc_btree.h"
  38 #include "xfs_log.h"
  39
  40 /*
  41  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
  42  */
  43
  44 /*
  45  * Reference counting access wrappers to the perag structures.
  46  * Because we never free per-ag structures, the only thing we
  47  * have to protect against changes is the tree structure itself.
  48  */
  49 struct xfs_perag *
  50 xfs_perag_get(
  51         struct xfs_mount        *mp,
  52         xfs_agnumber_t          agno)
  53 {
  54         struct xfs_perag        *pag;
  55         int                     ref = 0;
  56
  57         rcu_read_lock();
  58         pag = radix_tree_lookup(&mp->m_perag_tree, agno);
  59         if (pag) {
  60                 ASSERT(atomic_read(&pag->pag_ref) >= 0);
  61                 ref = atomic_inc_return(&pag->pag_ref);
  62         }
  63         rcu_read_unlock();
  64         trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
  65         return pag;
  66 }
  67
  68 /*
  69  * search from @first to find the next perag with the given tag set.
  70  */
  71 struct xfs_perag *
  72 xfs_perag_get_tag(
  73         struct xfs_mount        *mp,
  74         xfs_agnumber_t          first,
  75         int                     tag)
  76 {
  77         struct xfs_perag        *pag;
  78         int                     found;
  79         int                     ref;
  80
  81         rcu_read_lock();
  82         found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
  83                                         (void **)&pag, first, 1, tag);
  84         if (found <= 0) {
  85                 rcu_read_unlock();
  86                 return NULL;
  87         }
  88         ref = atomic_inc_return(&pag->pag_ref);
  89         rcu_read_unlock();
  90         trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
  91         return pag;
  92 }
  93
  94 void
  95 xfs_perag_put(
  96         struct xfs_perag        *pag)
  97 {
  98         int     ref;
  99
 100         ASSERT(atomic_read(&pag->pag_ref) > 0);
 101         ref = atomic_dec_return(&pag->pag_ref);
 102         trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
 103 }
 104
 105 /*
 106  * Check the validity of the SB found.
 107  */
 108 STATIC int
 109 xfs_mount_validate_sb(
 110         xfs_mount_t     *mp,
 111         xfs_sb_t        *sbp,
 112         bool            check_inprogress,
 113         bool            check_version)
 114 {
 115         if (sbp->sb_magicnum != XFS_SB_MAGIC) {
 116                 xfs_warn(mp, "bad magic number");
 117                 return -EWRONGFS;
 118         }
 119
 120
 121         if (!xfs_sb_good_version(sbp)) {
 122                 xfs_warn(mp, "bad version");
 123                 return -EWRONGFS;
 124         }
 125
 126         /*
 127          * Version 5 superblock feature mask validation. Reject combinations the
 128          * kernel cannot support up front before checking anything else. For
 129          * write validation, we don't need to check feature masks.
 130          */
 131         if (check_version && XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) {
 132                 if (xfs_sb_has_compat_feature(sbp,
 133                                         XFS_SB_FEAT_COMPAT_UNKNOWN)) {
 134                         xfs_warn(mp,
 135 "Superblock has unknown compatible features (0x%x) enabled.",
 136                                 (sbp->sb_features_compat &
 137                                                 XFS_SB_FEAT_COMPAT_UNKNOWN));
 138                         xfs_warn(mp,
 139 "Using a more recent kernel is recommended.");
 140                 }
 141
 142                 if (xfs_sb_has_ro_compat_feature(sbp,
 143                                         XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
 144                         xfs_alert(mp,
 145 "Superblock has unknown read-only compatible features (0x%x) enabled.",
 146                                 (sbp->sb_features_ro_compat &
 147                                                 XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
 148                         if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
 149                                 xfs_warn(mp,
 150 "Attempted to mount read-only compatible filesystem read-write.");
 151                                 xfs_warn(mp,
 152 "Filesystem can only be safely mounted read only.");
 153
 154                                 return -EINVAL;
 155                         }
 156                 }
 157                 if (xfs_sb_has_incompat_feature(sbp,
 158                                         XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
 159                         xfs_warn(mp,
 160 "Superblock has unknown incompatible features (0x%x) enabled.",
 161                                 (sbp->sb_features_incompat &
 162                                                 XFS_SB_FEAT_INCOMPAT_UNKNOWN));
 163                         xfs_warn(mp,
 164 "Filesystem can not be safely mounted by this kernel.");
 165                         return -EINVAL;
 166                 }
 167         } else if (xfs_sb_version_hascrc(sbp)) {
 168                 /*
 169                  * We can't read verify the sb LSN because the read verifier is
 170                  * called before the log is allocated and processed. We know the
 171                  * log is set up before write verifier (!check_version) calls,
 172                  * so just check it here.
 173                  */
 174                 if (!xfs_log_check_lsn(mp, sbp->sb_lsn))
 175                         return -EFSCORRUPTED;
 176         }
 177
 178         if (xfs_sb_version_has_pquotino(sbp)) {
 179                 if (sbp->sb_qflags & (XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD)) {
 180                         xfs_notice(mp,
 181                            "Version 5 of Super block has XFS_OQUOTA bits.");
 182                         return -EFSCORRUPTED;
 183                 }
 184         } else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
 185                                 XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
 186                         xfs_notice(mp,
 187 "Superblock earlier than Version 5 has XFS_[PQ]UOTA_{ENFD|CHKD} bits.");
 188                         return -EFSCORRUPTED;
 189         }
 190
 191         /*
 192          * Full inode chunks must be aligned to inode chunk size when
 193          * sparse inodes are enabled to support the sparse chunk
 194          * allocation algorithm and prevent overlapping inode records.
 195          */
 196         if (xfs_sb_version_hassparseinodes(sbp)) {
 197                 uint32_t        align;
 198
 199                 align = XFS_INODES_PER_CHUNK * sbp->sb_inodesize
 200                                 >> sbp->sb_blocklog;
 201                 if (sbp->sb_inoalignmt != align) {
 202                         xfs_warn(mp,
 203 "Inode block alignment (%u) must match chunk size (%u) for sparse inodes.",
 204                                  sbp->sb_inoalignmt, align);
 205                         return -EINVAL;
 206                 }
 207         }
 208
 209         if (unlikely(
 210             sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
 211                 xfs_warn(mp,
 212                 "filesystem is marked as having an external log; "
 213                 "specify logdev on the mount command line.");
 214                 return -EINVAL;
 215         }
 216
 217         if (unlikely(
 218             sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
 219                 xfs_warn(mp,
 220                 "filesystem is marked as having an internal log; "
 221                 "do not specify logdev on the mount command line.");
 222                 return -EINVAL;
 223         }
 224
 225         /*
 226          * More sanity checking.  Most of these were stolen directly from
 227          * xfs_repair.
 228          */
 229         if (unlikely(
 230             sbp->sb_agcount <= 0                                        ||
 231             sbp->sb_sectsize < XFS_MIN_SECTORSIZE                       ||
 232             sbp->sb_sectsize > XFS_MAX_SECTORSIZE                       ||
 233             sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG                    ||
 234             sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG                    ||
 235             sbp->sb_sectsize != (1 << sbp->sb_sectlog)                  ||
 236             sbp->sb_blocksize < XFS_MIN_BLOCKSIZE                       ||
 237             sbp->sb_blocksize > XFS_MAX_BLOCKSIZE                       ||
 238             sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG                    ||
 239             sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG                    ||
 240             sbp->sb_blocksize != (1 << sbp->sb_blocklog)                ||
 241             sbp->sb_dirblklog > XFS_MAX_BLOCKSIZE_LOG                   ||
 242             sbp->sb_inodesize < XFS_DINODE_MIN_SIZE                     ||
 243             sbp->sb_inodesize > XFS_DINODE_MAX_SIZE                     ||
 244             sbp->sb_inodelog < XFS_DINODE_MIN_LOG                       ||
 245             sbp->sb_inodelog > XFS_DINODE_MAX_LOG                       ||
 246             sbp->sb_inodesize != (1 << sbp->sb_inodelog)                ||
 247             sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE                    ||
 248             sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
 249             (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)   ||
 250             (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)  ||
 251             (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)  ||
 252             (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)    ||
 253             sbp->sb_dblocks == 0                                        ||
 254             sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)                      ||
 255             sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)                      ||
 256             sbp->sb_shared_vn != 0)) {
 257                 xfs_notice(mp, "SB sanity check failed");
 258                 return -EFSCORRUPTED;
 259         }
 260
 261         /*
 262          * Until this is fixed only page-sized or smaller data blocks work.
 263          */
 264         if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
 265                 xfs_warn(mp,
 266                 "File system with blocksize %d bytes. "
 267                 "Only pagesize (%ld) or less will currently work.",
 268                                 sbp->sb_blocksize, PAGE_SIZE);
 269                 return -ENOSYS;
 270         }
 271
 272         /*
 273          * Currently only very few inode sizes are supported.
 274          */
 275         switch (sbp->sb_inodesize) {
 276         case 256:
 277         case 512:
 278         case 1024:
 279         case 2048:
 280                 break;
 281         default:
 282                 xfs_warn(mp, "inode size of %d bytes not supported",
 283                                 sbp->sb_inodesize);
 284                 return -ENOSYS;
 285         }
 286
 287         if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
 288             xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
 289                 xfs_warn(mp,
 290                 "file system too large to be mounted on this system.");
 291                 return -EFBIG;
 292         }
 293
 294         if (check_inprogress && sbp->sb_inprogress) {
 295                 xfs_warn(mp, "Offline file system operation in progress!");
 296                 return -EFSCORRUPTED;
 297         }
 298         return 0;
 299 }
 300
 301 void
 302 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
 303 {
 304         /*
 305          * older mkfs doesn't initialize quota inodes to NULLFSINO. This
 306          * leads to in-core values having two different values for a quota
 307          * inode to be invalid: 0 and NULLFSINO. Change it to a single value
 308          * NULLFSINO.
 309          *
 310          * Note that this change affect only the in-core values. These
 311          * values are not written back to disk unless any quota information
 312          * is written to the disk. Even in that case, sb_pquotino field is
 313          * not written to disk unless the superblock supports pquotino.
 314          */
 315         if (sbp->sb_uquotino == 0)
 316                 sbp->sb_uquotino = NULLFSINO;
 317         if (sbp->sb_gquotino == 0)
 318                 sbp->sb_gquotino = NULLFSINO;
 319         if (sbp->sb_pquotino == 0)
 320                 sbp->sb_pquotino = NULLFSINO;
 321
 322         /*
 323          * We need to do these manipilations only if we are working
 324          * with an older version of on-disk superblock.
 325          */
 326         if (xfs_sb_version_has_pquotino(sbp))
 327                 return;
 328
 329         if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
 330                 sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
 331                                         XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
 332         if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
 333                 sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
 334                                         XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
 335         sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
 336
 337         if (sbp->sb_qflags & XFS_PQUOTA_ACCT)  {
 338                 /*
 339                  * In older version of superblock, on-disk superblock only
 340                  * has sb_gquotino, and in-core superblock has both sb_gquotino
 341                  * and sb_pquotino. But, only one of them is supported at any
 342                  * point of time. So, if PQUOTA is set in disk superblock,
 343                  * copy over sb_gquotino to sb_pquotino.
 344                  */
 345                 sbp->sb_pquotino = sbp->sb_gquotino;
 346                 sbp->sb_gquotino = NULLFSINO;
 347         }
 348 }
 349
 350 static void
 351 __xfs_sb_from_disk(
 352         struct xfs_sb   *to,
 353         xfs_dsb_t       *from,
 354         bool            convert_xquota)
 355 {
 356         to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
 357         to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
 358         to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
 359         to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
 360         to->sb_rextents = be64_to_cpu(from->sb_rextents);
 361         memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
 362         to->sb_logstart = be64_to_cpu(from->sb_logstart);
 363         to->sb_rootino = be64_to_cpu(from->sb_rootino);
 364         to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
 365         to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
 366         to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
 367         to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
 368         to->sb_agcount = be32_to_cpu(from->sb_agcount);
 369         to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
 370         to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
 371         to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
 372         to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
 373         to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
 374         to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
 375         memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
 376         to->sb_blocklog = from->sb_blocklog;
 377         to->sb_sectlog = from->sb_sectlog;
 378         to->sb_inodelog = from->sb_inodelog;
 379         to->sb_inopblog = from->sb_inopblog;
 380         to->sb_agblklog = from->sb_agblklog;
 381         to->sb_rextslog = from->sb_rextslog;
 382         to->sb_inprogress = from->sb_inprogress;
 383         to->sb_imax_pct = from->sb_imax_pct;
 384         to->sb_icount = be64_to_cpu(from->sb_icount);
 385         to->sb_ifree = be64_to_cpu(from->sb_ifree);
 386         to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
 387         to->sb_frextents = be64_to_cpu(from->sb_frextents);
 388         to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
 389         to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
 390         to->sb_qflags = be16_to_cpu(from->sb_qflags);
 391         to->sb_flags = from->sb_flags;
 392         to->sb_shared_vn = from->sb_shared_vn;
 393         to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
 394         to->sb_unit = be32_to_cpu(from->sb_unit);
 395         to->sb_width = be32_to_cpu(from->sb_width);
 396         to->sb_dirblklog = from->sb_dirblklog;
 397         to->sb_logsectlog = from->sb_logsectlog;
 398         to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
 399         to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
 400         to->sb_features2 = be32_to_cpu(from->sb_features2);
 401         to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
 402         to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
 403         to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
 404         to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
 405         to->sb_features_log_incompat =
 406                                 be32_to_cpu(from->sb_features_log_incompat);
 407         /* crc is only used on disk, not in memory; just init to 0 here. */
 408         to->sb_crc = 0;
 409         to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
 410         to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
 411         to->sb_lsn = be64_to_cpu(from->sb_lsn);
 412         /*
 413          * sb_meta_uuid is only on disk if it differs from sb_uuid and the
 414          * feature flag is set; if not set we keep it only in memory.
 415          */
 416         if (xfs_sb_version_hasmetauuid(to))
 417                 uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
 418         else
 419                 uuid_copy(&to->sb_meta_uuid, &from->sb_uuid);
 420         /* Convert on-disk flags to in-memory flags? */
 421         if (convert_xquota)
 422                 xfs_sb_quota_from_disk(to);
 423 }
 424
 425 void
 426 xfs_sb_from_disk(
 427         struct xfs_sb   *to,
 428         xfs_dsb_t       *from)
 429 {
 430         __xfs_sb_from_disk(to, from, true);
 431 }
 432
 433 static void
 434 xfs_sb_quota_to_disk(
 435         struct xfs_dsb  *to,
 436         struct xfs_sb   *from)
 437 {
 438         __uint16_t      qflags = from->sb_qflags;
 439
 440         to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
 441         if (xfs_sb_version_has_pquotino(from)) {
 442                 to->sb_qflags = cpu_to_be16(from->sb_qflags);
 443                 to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
 444                 to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
 445                 return;
 446         }
 447
 448         /*
 449          * The in-core version of sb_qflags do not have XFS_OQUOTA_*
 450          * flags, whereas the on-disk version does.  So, convert incore
 451          * XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
 452          */
 453         qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
 454                         XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
 455
 456         if (from->sb_qflags &
 457                         (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
 458                 qflags |= XFS_OQUOTA_ENFD;
 459         if (from->sb_qflags &
 460                         (XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
 461                 qflags |= XFS_OQUOTA_CHKD;
 462         to->sb_qflags = cpu_to_be16(qflags);
 463
 464         /*
 465          * GQUOTINO and PQUOTINO cannot be used together in versions
 466          * of superblock that do not have pquotino. from->sb_flags
 467          * tells us which quota is active and should be copied to
 468          * disk. If neither are active, we should NULL the inode.
 469          *
 470          * In all cases, the separate pquotino must remain 0 because it
 471          * it beyond the "end" of the valid non-pquotino superblock.
 472          */
 473         if (from->sb_qflags & XFS_GQUOTA_ACCT)
 474                 to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
 475         else if (from->sb_qflags & XFS_PQUOTA_ACCT)
 476                 to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
 477         else {
 478                 /*
 479                  * We can't rely on just the fields being logged to tell us
 480                  * that it is safe to write NULLFSINO - we should only do that
 481                  * if quotas are not actually enabled. Hence only write
 482                  * NULLFSINO if both in-core quota inodes are NULL.
 483                  */
 484                 if (from->sb_gquotino == NULLFSINO &&
 485                     from->sb_pquotino == NULLFSINO)
 486                         to->sb_gquotino = cpu_to_be64(NULLFSINO);
 487         }
 488
 489         to->sb_pquotino = 0;
 490 }
 491
 492 void
 493 xfs_sb_to_disk(
 494         struct xfs_dsb  *to,
 495         struct xfs_sb   *from)
 496 {
 497         xfs_sb_quota_to_disk(to, from);
 498
 499         to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
 500         to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
 501         to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
 502         to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
 503         to->sb_rextents = cpu_to_be64(from->sb_rextents);
 504         memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
 505         to->sb_logstart = cpu_to_be64(from->sb_logstart);
 506         to->sb_rootino = cpu_to_be64(from->sb_rootino);
 507         to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
 508         to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
 509         to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
 510         to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
 511         to->sb_agcount = cpu_to_be32(from->sb_agcount);
 512         to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
 513         to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
 514         to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
 515         to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
 516         to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
 517         to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
 518         memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
 519         to->sb_blocklog = from->sb_blocklog;
 520         to->sb_sectlog = from->sb_sectlog;
 521         to->sb_inodelog = from->sb_inodelog;
 522         to->sb_inopblog = from->sb_inopblog;
 523         to->sb_agblklog = from->sb_agblklog;
 524         to->sb_rextslog = from->sb_rextslog;
 525         to->sb_inprogress = from->sb_inprogress;
 526         to->sb_imax_pct = from->sb_imax_pct;
 527         to->sb_icount = cpu_to_be64(from->sb_icount);
 528         to->sb_ifree = cpu_to_be64(from->sb_ifree);
 529         to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
 530         to->sb_frextents = cpu_to_be64(from->sb_frextents);
 531
 532         to->sb_flags = from->sb_flags;
 533         to->sb_shared_vn = from->sb_shared_vn;
 534         to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
 535         to->sb_unit = cpu_to_be32(from->sb_unit);
 536         to->sb_width = cpu_to_be32(from->sb_width);
 537         to->sb_dirblklog = from->sb_dirblklog;
 538         to->sb_logsectlog = from->sb_logsectlog;
 539         to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
 540         to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
 541
 542         /*
 543          * We need to ensure that bad_features2 always matches features2.
 544          * Hence we enforce that here rather than having to remember to do it
 545          * everywhere else that updates features2.
 546          */
 547         from->sb_bad_features2 = from->sb_features2;
 548         to->sb_features2 = cpu_to_be32(from->sb_features2);
 549         to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
 550
 551         if (xfs_sb_version_hascrc(from)) {
 552                 to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
 553                 to->sb_features_ro_compat =
 554                                 cpu_to_be32(from->sb_features_ro_compat);
 555                 to->sb_features_incompat =
 556                                 cpu_to_be32(from->sb_features_incompat);
 557                 to->sb_features_log_incompat =
 558                                 cpu_to_be32(from->sb_features_log_incompat);
 559                 to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
 560                 to->sb_lsn = cpu_to_be64(from->sb_lsn);
 561                 if (xfs_sb_version_hasmetauuid(from))
 562                         uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
 563         }
 564 }
 565
 566 static int
 567 xfs_sb_verify(
 568         struct xfs_buf  *bp,
 569         bool            check_version)
 570 {
 571         struct xfs_mount *mp = bp->b_target->bt_mount;
 572         struct xfs_sb   sb;
 573
 574         /*
 575          * Use call variant which doesn't convert quota flags from disk
 576          * format, because xfs_mount_validate_sb checks the on-disk flags.
 577          */
 578         __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
 579
 580         /*
 581          * Only check the in progress field for the primary superblock as
 582          * mkfs.xfs doesn't clear it from secondary superblocks.
 583          */
 584         return xfs_mount_validate_sb(mp, &sb,
 585                                      bp->b_maps[0].bm_bn == XFS_SB_DADDR,
 586                                      check_version);
 587 }
 588
 589 /*
 590  * If the superblock has the CRC feature bit set or the CRC field is non-null,
 591  * check that the CRC is valid.  We check the CRC field is non-null because a
 592  * single bit error could clear the feature bit and unused parts of the
 593  * superblock are supposed to be zero. Hence a non-null crc field indicates that
 594  * we've potentially lost a feature bit and we should check it anyway.
 595  *
 596  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
 597  * last field in V4 secondary superblocks.  So for secondary superblocks,
 598  * we are more forgiving, and ignore CRC failures if the primary doesn't
 599  * indicate that the fs version is V5.
 600  */
 601 static void
 602 xfs_sb_read_verify(
 603         struct xfs_buf  *bp)
 604 {
 605         struct xfs_mount *mp = bp->b_target->bt_mount;
 606         struct xfs_dsb  *dsb = XFS_BUF_TO_SBP(bp);
 607         int             error;
 608
 609         /*
 610          * open code the version check to avoid needing to convert the entire
 611          * superblock from disk order just to check the version number
 612          */
 613         if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
 614             (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
 615                                                 XFS_SB_VERSION_5) ||
 616              dsb->sb_crc != 0)) {
 617
 618                 if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
 619                         /* Only fail bad secondaries on a known V5 filesystem */
 620                         if (bp->b_bn == XFS_SB_DADDR ||
 621                             xfs_sb_version_hascrc(&mp->m_sb)) {
 622                                 error = -EFSBADCRC;
 623                                 goto out_error;
 624                         }
 625                 }
 626         }
 627         error = xfs_sb_verify(bp, true);
 628
 629 out_error:
 630         if (error) {
 631                 xfs_buf_ioerror(bp, error);
 632                 if (error == -EFSCORRUPTED || error == -EFSBADCRC)
 633                         xfs_verifier_error(bp);
 634         }
 635 }
 636
 637 /*
 638  * We may be probed for a filesystem match, so we may not want to emit
 639  * messages when the superblock buffer is not actually an XFS superblock.
 640  * If we find an XFS superblock, then run a normal, noisy mount because we are
 641  * really going to mount it and want to know about errors.
 642  */
 643 static void
 644 xfs_sb_quiet_read_verify(
 645         struct xfs_buf  *bp)
 646 {
 647         struct xfs_dsb  *dsb = XFS_BUF_TO_SBP(bp);
 648
 649         if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
 650                 /* XFS filesystem, verify noisily! */
 651                 xfs_sb_read_verify(bp);
 652                 return;
 653         }
 654         /* quietly fail */
 655         xfs_buf_ioerror(bp, -EWRONGFS);
 656 }
 657
 658 static void
 659 xfs_sb_write_verify(
 660         struct xfs_buf          *bp)
 661 {
 662         struct xfs_mount        *mp = bp->b_target->bt_mount;
 663         struct xfs_buf_log_item *bip = bp->b_fspriv;
 664         int                     error;
 665
 666         error = xfs_sb_verify(bp, false);
 667         if (error) {
 668                 xfs_buf_ioerror(bp, error);
 669                 xfs_verifier_error(bp);
 670                 return;
 671         }
 672
 673         if (!xfs_sb_version_hascrc(&mp->m_sb))
 674                 return;
 675
 676         if (bip)
 677                 XFS_BUF_TO_SBP(bp)->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
 678
 679         xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
 680 }
 681
 682 const struct xfs_buf_ops xfs_sb_buf_ops = {
 683         .name = "xfs_sb",
 684         .verify_read = xfs_sb_read_verify,
 685         .verify_write = xfs_sb_write_verify,
 686 };
 687
 688 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
 689         .name = "xfs_sb_quiet",
 690         .verify_read = xfs_sb_quiet_read_verify,
 691         .verify_write = xfs_sb_write_verify,
 692 };
 693
 694 /*
 695  * xfs_mount_common
 696  *
 697  * Mount initialization code establishing various mount
 698  * fields from the superblock associated with the given
 699  * mount structure
 700  */
 701 void
 702 xfs_sb_mount_common(
 703         struct xfs_mount *mp,
 704         struct xfs_sb   *sbp)
 705 {
 706         mp->m_agfrotor = mp->m_agirotor = 0;
 707         spin_lock_init(&mp->m_agirotor_lock);
 708         mp->m_maxagi = mp->m_sb.sb_agcount;
 709         mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
 710         mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
 711         mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
 712         mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
 713         mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
 714         mp->m_blockmask = sbp->sb_blocksize - 1;
 715         mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
 716         mp->m_blockwmask = mp->m_blockwsize - 1;
 717
 718         mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
 719         mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
 720         mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
 721         mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
 722
 723         mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
 724         mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
 725         mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
 726         mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
 727
 728         mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
 729         mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
 730         mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
 731         mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
 732
 733         mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
 734         mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
 735                                         sbp->sb_inopblock);
 736         mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
 737
 738         if (sbp->sb_spino_align)
 739                 mp->m_ialloc_min_blks = sbp->sb_spino_align;
 740         else
 741                 mp->m_ialloc_min_blks = mp->m_ialloc_blks;
 742 }
 743
 744 /*
 745  * xfs_initialize_perag_data
 746  *
 747  * Read in each per-ag structure so we can count up the number of
 748  * allocated inodes, free inodes and used filesystem blocks as this
 749  * information is no longer persistent in the superblock. Once we have
 750  * this information, write it into the in-core superblock structure.
 751  */
 752 int
 753 xfs_initialize_perag_data(
 754         struct xfs_mount *mp,
 755         xfs_agnumber_t  agcount)
 756 {
 757         xfs_agnumber_t  index;
 758         xfs_perag_t     *pag;
 759         xfs_sb_t        *sbp = &mp->m_sb;
 760         uint64_t        ifree = 0;
 761         uint64_t        ialloc = 0;
 762         uint64_t        bfree = 0;
 763         uint64_t        bfreelst = 0;
 764         uint64_t        btree = 0;
 765         int             error;
 766
 767         for (index = 0; index < agcount; index++) {
 768                 /*
 769                  * read the agf, then the agi. This gets us
 770                  * all the information we need and populates the
 771                  * per-ag structures for us.
 772                  */
 773                 error = xfs_alloc_pagf_init(mp, NULL, index, 0);
 774                 if (error)
 775                         return error;
 776
 777                 error = xfs_ialloc_pagi_init(mp, NULL, index);
 778                 if (error)
 779                         return error;
 780                 pag = xfs_perag_get(mp, index);
 781                 ifree += pag->pagi_freecount;
 782                 ialloc += pag->pagi_count;
 783                 bfree += pag->pagf_freeblks;
 784                 bfreelst += pag->pagf_flcount;
 785                 btree += pag->pagf_btreeblks;
 786                 xfs_perag_put(pag);
 787         }
 788
 789         /* Overwrite incore superblock counters with just-read data */
 790         spin_lock(&mp->m_sb_lock);
 791         sbp->sb_ifree = ifree;
 792         sbp->sb_icount = ialloc;
 793         sbp->sb_fdblocks = bfree + bfreelst + btree;
 794         spin_unlock(&mp->m_sb_lock);
 795
 796         xfs_reinit_percpu_counters(mp);
 797
 798         return 0;
 799 }
 800
 801 /*
 802  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
 803  * into the superblock buffer to be logged.  It does not provide the higher
 804  * level of locking that is needed to protect the in-core superblock from
 805  * concurrent access.
 806  */
 807 void
 808 xfs_log_sb(
 809         struct xfs_trans        *tp)
 810 {
 811         struct xfs_mount        *mp = tp->t_mountp;
 812         struct xfs_buf          *bp = xfs_trans_getsb(tp, mp, 0);
 813
 814         mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount);
 815         mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree);
 816         mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
 817
 818         xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
 819         xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
 820         xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
 821 }
 822
 823 /*
 824  * xfs_sync_sb
 825  *
 826  * Sync the superblock to disk.
 827  *
 828  * Note that the caller is responsible for checking the frozen state of the
 829  * filesystem. This procedure uses the non-blocking transaction allocator and
 830  * thus will allow modifications to a frozen fs. This is required because this
 831  * code can be called during the process of freezing where use of the high-level
 832  * allocator would deadlock.
 833  */
 834 int
 835 xfs_sync_sb(
 836         struct xfs_mount        *mp,
 837         bool                    wait)
 838 {
 839         struct xfs_trans        *tp;
 840         int                     error;
 841
 842         tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_CHANGE, KM_SLEEP);
 843         error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
 844         if (error) {
 845                 xfs_trans_cancel(tp);
 846                 return error;
 847         }
 848
 849         xfs_log_sb(tp);
 850         if (wait)
 851                 xfs_trans_set_sync(tp);
 852         return xfs_trans_commit(tp);
 853 }