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_defer.h"
  28 #include "xfs_inode.h"
  29 #include "xfs_ialloc.h"
  30 #include "xfs_alloc.h"
  31 #include "xfs_error.h"
  32 #include "xfs_trace.h"
  33 #include "xfs_cksum.h"
  34 #include "xfs_trans.h"
  35 #include "xfs_buf_item.h"
  36 #include "xfs_bmap_btree.h"
  37 #include "xfs_alloc_btree.h"
  38 #include "xfs_ialloc_btree.h"
  39 #include "xfs_log.h"
  40 #include "xfs_rmap_btree.h"
  41 #include "xfs_bmap.h"
  42 #include "xfs_refcount_btree.h"
  43
  44 /*
  45  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
  46  */
  47
  48 /*
  49  * Reference counting access wrappers to the perag structures.
  50  * Because we never free per-ag structures, the only thing we
  51  * have to protect against changes is the tree structure itself.
  52  */
  53 struct xfs_perag *
  54 xfs_perag_get(
  55         struct xfs_mount        *mp,
  56         xfs_agnumber_t          agno)
  57 {
  58         struct xfs_perag        *pag;
  59         int                     ref = 0;
  60
  61         rcu_read_lock();
  62         pag = radix_tree_lookup(&mp->m_perag_tree, agno);
  63         if (pag) {
  64                 ASSERT(atomic_read(&pag->pag_ref) >= 0);
  65                 ref = atomic_inc_return(&pag->pag_ref);
  66         }
  67         rcu_read_unlock();
  68         trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
  69         return pag;
  70 }
  71
  72 /*
  73  * search from @first to find the next perag with the given tag set.
  74  */
  75 struct xfs_perag *
  76 xfs_perag_get_tag(
  77         struct xfs_mount        *mp,
  78         xfs_agnumber_t          first,
  79         int                     tag)
  80 {
  81         struct xfs_perag        *pag;
  82         int                     found;
  83         int                     ref;
  84
  85         rcu_read_lock();
  86         found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
  87                                         (void **)&pag, first, 1, tag);
  88         if (found <= 0) {
  89                 rcu_read_unlock();
  90                 return NULL;
  91         }
  92         ref = atomic_inc_return(&pag->pag_ref);
  93         rcu_read_unlock();
  94         trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
  95         return pag;
  96 }
  97
  98 void
  99 xfs_perag_put(
 100         struct xfs_perag        *pag)
 101 {
 102         int     ref;
 103
 104         ASSERT(atomic_read(&pag->pag_ref) > 0);
 105         ref = atomic_dec_return(&pag->pag_ref);
 106         trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
 107 }
 108
 109 /*
 110  * Check the validity of the SB found.
 111  */
 112 STATIC int
 113 xfs_mount_validate_sb(
 114         xfs_mount_t     *mp,
 115         xfs_sb_t        *sbp,
 116         bool            check_inprogress,
 117         bool            check_version)
 118 {
 119         if (sbp->sb_magicnum != XFS_SB_MAGIC) {
 120                 xfs_warn(mp, "bad magic number");
 121                 return -EWRONGFS;
 122         }
 123
 124
 125         if (!xfs_sb_good_version(sbp)) {
 126                 xfs_warn(mp, "bad version");
 127                 return -EWRONGFS;
 128         }
 129
 130         /*
 131          * Version 5 superblock feature mask validation. Reject combinations the
 132          * kernel cannot support up front before checking anything else. For
 133          * write validation, we don't need to check feature masks.
 134          */
 135         if (check_version && XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) {
 136                 if (xfs_sb_has_compat_feature(sbp,
 137                                         XFS_SB_FEAT_COMPAT_UNKNOWN)) {
 138                         xfs_warn(mp,
 139 "Superblock has unknown compatible features (0x%x) enabled.",
 140                                 (sbp->sb_features_compat &
 141                                                 XFS_SB_FEAT_COMPAT_UNKNOWN));
 142                         xfs_warn(mp,
 143 "Using a more recent kernel is recommended.");
 144                 }
 145
 146                 if (xfs_sb_has_ro_compat_feature(sbp,
 147                                         XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) {
 148                         xfs_alert(mp,
 149 "Superblock has unknown read-only compatible features (0x%x) enabled.",
 150                                 (sbp->sb_features_ro_compat &
 151                                                 XFS_SB_FEAT_RO_COMPAT_UNKNOWN));
 152                         if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
 153                                 xfs_warn(mp,
 154 "Attempted to mount read-only compatible filesystem read-write.");
 155                                 xfs_warn(mp,
 156 "Filesystem can only be safely mounted read only.");
 157
 158                                 return -EINVAL;
 159                         }
 160                 }
 161                 if (xfs_sb_has_incompat_feature(sbp,
 162                                         XFS_SB_FEAT_INCOMPAT_UNKNOWN)) {
 163                         xfs_warn(mp,
 164 "Superblock has unknown incompatible features (0x%x) enabled.",
 165                                 (sbp->sb_features_incompat &
 166                                                 XFS_SB_FEAT_INCOMPAT_UNKNOWN));
 167                         xfs_warn(mp,
 168 "Filesystem can not be safely mounted by this kernel.");
 169                         return -EINVAL;
 170                 }
 171         } else if (xfs_sb_version_hascrc(sbp)) {
 172                 /*
 173                  * We can't read verify the sb LSN because the read verifier is
 174                  * called before the log is allocated and processed. We know the
 175                  * log is set up before write verifier (!check_version) calls,
 176                  * so just check it here.
 177                  */
 178                 if (!xfs_log_check_lsn(mp, sbp->sb_lsn))
 179                         return -EFSCORRUPTED;
 180         }
 181
 182         if (xfs_sb_version_has_pquotino(sbp)) {
 183                 if (sbp->sb_qflags & (XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD)) {
 184                         xfs_notice(mp,
 185                            "Version 5 of Super block has XFS_OQUOTA bits.");
 186                         return -EFSCORRUPTED;
 187                 }
 188         } else if (sbp->sb_qflags & (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD |
 189                                 XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD)) {
 190                         xfs_notice(mp,
 191 "Superblock earlier than Version 5 has XFS_[PQ]UOTA_{ENFD|CHKD} bits.");
 192                         return -EFSCORRUPTED;
 193         }
 194
 195         /*
 196          * Full inode chunks must be aligned to inode chunk size when
 197          * sparse inodes are enabled to support the sparse chunk
 198          * allocation algorithm and prevent overlapping inode records.
 199          */
 200         if (xfs_sb_version_hassparseinodes(sbp)) {
 201                 uint32_t        align;
 202
 203                 align = XFS_INODES_PER_CHUNK * sbp->sb_inodesize
 204                                 >> sbp->sb_blocklog;
 205                 if (sbp->sb_inoalignmt != align) {
 206                         xfs_warn(mp,
 207 "Inode block alignment (%u) must match chunk size (%u) for sparse inodes.",
 208                                  sbp->sb_inoalignmt, align);
 209                         return -EINVAL;
 210                 }
 211         }
 212
 213         if (unlikely(
 214             sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
 215                 xfs_warn(mp,
 216                 "filesystem is marked as having an external log; "
 217                 "specify logdev on the mount command line.");
 218                 return -EINVAL;
 219         }
 220
 221         if (unlikely(
 222             sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
 223                 xfs_warn(mp,
 224                 "filesystem is marked as having an internal log; "
 225                 "do not specify logdev on the mount command line.");
 226                 return -EINVAL;
 227         }
 228
 229         /*
 230          * More sanity checking.  Most of these were stolen directly from
 231          * xfs_repair.
 232          */
 233         if (unlikely(
 234             sbp->sb_agcount <= 0                                        ||
 235             sbp->sb_sectsize < XFS_MIN_SECTORSIZE                       ||
 236             sbp->sb_sectsize > XFS_MAX_SECTORSIZE                       ||
 237             sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG                    ||
 238             sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG                    ||
 239             sbp->sb_sectsize != (1 << sbp->sb_sectlog)                  ||
 240             sbp->sb_blocksize < XFS_MIN_BLOCKSIZE                       ||
 241             sbp->sb_blocksize > XFS_MAX_BLOCKSIZE                       ||
 242             sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG                    ||
 243             sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG                    ||
 244             sbp->sb_blocksize != (1 << sbp->sb_blocklog)                ||
 245             sbp->sb_dirblklog + sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
 246             sbp->sb_inodesize < XFS_DINODE_MIN_SIZE                     ||
 247             sbp->sb_inodesize > XFS_DINODE_MAX_SIZE                     ||
 248             sbp->sb_inodelog < XFS_DINODE_MIN_LOG                       ||
 249             sbp->sb_inodelog > XFS_DINODE_MAX_LOG                       ||
 250             sbp->sb_inodesize != (1 << sbp->sb_inodelog)                ||
 251             sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE                    ||
 252             sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
 253             (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)   ||
 254             (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)  ||
 255             (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)  ||
 256             (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */)    ||
 257             sbp->sb_dblocks == 0                                        ||
 258             sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp)                      ||
 259             sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp)                      ||
 260             sbp->sb_shared_vn != 0)) {
 261                 xfs_notice(mp, "SB sanity check failed");
 262                 return -EFSCORRUPTED;
 263         }
 264
 265         if (xfs_sb_version_hascrc(&mp->m_sb) &&
 266             sbp->sb_blocksize < XFS_MIN_CRC_BLOCKSIZE) {
 267                 xfs_notice(mp, "v5 SB sanity check failed");
 268                 return -EFSCORRUPTED;
 269         }
 270
 271         /*
 272          * Until this is fixed only page-sized or smaller data blocks work.
 273          */
 274         if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
 275                 xfs_warn(mp,
 276                 "File system with blocksize %d bytes. "
 277                 "Only pagesize (%ld) or less will currently work.",
 278                                 sbp->sb_blocksize, PAGE_SIZE);
 279                 return -ENOSYS;
 280         }
 281
 282         /*
 283          * Currently only very few inode sizes are supported.
 284          */
 285         switch (sbp->sb_inodesize) {
 286         case 256:
 287         case 512:
 288         case 1024:
 289         case 2048:
 290                 break;
 291         default:
 292                 xfs_warn(mp, "inode size of %d bytes not supported",
 293                                 sbp->sb_inodesize);
 294                 return -ENOSYS;
 295         }
 296
 297         if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
 298             xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
 299                 xfs_warn(mp,
 300                 "file system too large to be mounted on this system.");
 301                 return -EFBIG;
 302         }
 303
 304         if (check_inprogress && sbp->sb_inprogress) {
 305                 xfs_warn(mp, "Offline file system operation in progress!");
 306                 return -EFSCORRUPTED;
 307         }
 308         return 0;
 309 }
 310
 311 void
 312 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
 313 {
 314         /*
 315          * older mkfs doesn't initialize quota inodes to NULLFSINO. This
 316          * leads to in-core values having two different values for a quota
 317          * inode to be invalid: 0 and NULLFSINO. Change it to a single value
 318          * NULLFSINO.
 319          *
 320          * Note that this change affect only the in-core values. These
 321          * values are not written back to disk unless any quota information
 322          * is written to the disk. Even in that case, sb_pquotino field is
 323          * not written to disk unless the superblock supports pquotino.
 324          */
 325         if (sbp->sb_uquotino == 0)
 326                 sbp->sb_uquotino = NULLFSINO;
 327         if (sbp->sb_gquotino == 0)
 328                 sbp->sb_gquotino = NULLFSINO;
 329         if (sbp->sb_pquotino == 0)
 330                 sbp->sb_pquotino = NULLFSINO;
 331
 332         /*
 333          * We need to do these manipilations only if we are working
 334          * with an older version of on-disk superblock.
 335          */
 336         if (xfs_sb_version_has_pquotino(sbp))
 337                 return;
 338
 339         if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
 340                 sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
 341                                         XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
 342         if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
 343                 sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
 344                                         XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
 345         sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
 346
 347         if (sbp->sb_qflags & XFS_PQUOTA_ACCT &&
 348             sbp->sb_gquotino != NULLFSINO)  {
 349                 /*
 350                  * In older version of superblock, on-disk superblock only
 351                  * has sb_gquotino, and in-core superblock has both sb_gquotino
 352                  * and sb_pquotino. But, only one of them is supported at any
 353                  * point of time. So, if PQUOTA is set in disk superblock,
 354                  * copy over sb_gquotino to sb_pquotino.  The NULLFSINO test
 355                  * above is to make sure we don't do this twice and wipe them
 356                  * both out!
 357                  */
 358                 sbp->sb_pquotino = sbp->sb_gquotino;
 359                 sbp->sb_gquotino = NULLFSINO;
 360         }
 361 }
 362
 363 static void
 364 __xfs_sb_from_disk(
 365         struct xfs_sb   *to,
 366         xfs_dsb_t       *from,
 367         bool            convert_xquota)
 368 {
 369         to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
 370         to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
 371         to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
 372         to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
 373         to->sb_rextents = be64_to_cpu(from->sb_rextents);
 374         memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
 375         to->sb_logstart = be64_to_cpu(from->sb_logstart);
 376         to->sb_rootino = be64_to_cpu(from->sb_rootino);
 377         to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
 378         to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
 379         to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
 380         to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
 381         to->sb_agcount = be32_to_cpu(from->sb_agcount);
 382         to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
 383         to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
 384         to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
 385         to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
 386         to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
 387         to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
 388         memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
 389         to->sb_blocklog = from->sb_blocklog;
 390         to->sb_sectlog = from->sb_sectlog;
 391         to->sb_inodelog = from->sb_inodelog;
 392         to->sb_inopblog = from->sb_inopblog;
 393         to->sb_agblklog = from->sb_agblklog;
 394         to->sb_rextslog = from->sb_rextslog;
 395         to->sb_inprogress = from->sb_inprogress;
 396         to->sb_imax_pct = from->sb_imax_pct;
 397         to->sb_icount = be64_to_cpu(from->sb_icount);
 398         to->sb_ifree = be64_to_cpu(from->sb_ifree);
 399         to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
 400         to->sb_frextents = be64_to_cpu(from->sb_frextents);
 401         to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
 402         to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
 403         to->sb_qflags = be16_to_cpu(from->sb_qflags);
 404         to->sb_flags = from->sb_flags;
 405         to->sb_shared_vn = from->sb_shared_vn;
 406         to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
 407         to->sb_unit = be32_to_cpu(from->sb_unit);
 408         to->sb_width = be32_to_cpu(from->sb_width);
 409         to->sb_dirblklog = from->sb_dirblklog;
 410         to->sb_logsectlog = from->sb_logsectlog;
 411         to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
 412         to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
 413         to->sb_features2 = be32_to_cpu(from->sb_features2);
 414         to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
 415         to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
 416         to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
 417         to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
 418         to->sb_features_log_incompat =
 419                                 be32_to_cpu(from->sb_features_log_incompat);
 420         /* crc is only used on disk, not in memory; just init to 0 here. */
 421         to->sb_crc = 0;
 422         to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
 423         to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
 424         to->sb_lsn = be64_to_cpu(from->sb_lsn);
 425         /*
 426          * sb_meta_uuid is only on disk if it differs from sb_uuid and the
 427          * feature flag is set; if not set we keep it only in memory.
 428          */
 429         if (xfs_sb_version_hasmetauuid(to))
 430                 uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
 431         else
 432                 uuid_copy(&to->sb_meta_uuid, &from->sb_uuid);
 433         /* Convert on-disk flags to in-memory flags? */
 434         if (convert_xquota)
 435                 xfs_sb_quota_from_disk(to);
 436 }
 437
 438 void
 439 xfs_sb_from_disk(
 440         struct xfs_sb   *to,
 441         xfs_dsb_t       *from)
 442 {
 443         __xfs_sb_from_disk(to, from, true);
 444 }
 445
 446 static void
 447 xfs_sb_quota_to_disk(
 448         struct xfs_dsb  *to,
 449         struct xfs_sb   *from)
 450 {
 451         __uint16_t      qflags = from->sb_qflags;
 452
 453         to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
 454         if (xfs_sb_version_has_pquotino(from)) {
 455                 to->sb_qflags = cpu_to_be16(from->sb_qflags);
 456                 to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
 457                 to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
 458                 return;
 459         }
 460
 461         /*
 462          * The in-core version of sb_qflags do not have XFS_OQUOTA_*
 463          * flags, whereas the on-disk version does.  So, convert incore
 464          * XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
 465          */
 466         qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
 467                         XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
 468
 469         if (from->sb_qflags &
 470                         (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
 471                 qflags |= XFS_OQUOTA_ENFD;
 472         if (from->sb_qflags &
 473                         (XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
 474                 qflags |= XFS_OQUOTA_CHKD;
 475         to->sb_qflags = cpu_to_be16(qflags);
 476
 477         /*
 478          * GQUOTINO and PQUOTINO cannot be used together in versions
 479          * of superblock that do not have pquotino. from->sb_flags
 480          * tells us which quota is active and should be copied to
 481          * disk. If neither are active, we should NULL the inode.
 482          *
 483          * In all cases, the separate pquotino must remain 0 because it
 484          * it beyond the "end" of the valid non-pquotino superblock.
 485          */
 486         if (from->sb_qflags & XFS_GQUOTA_ACCT)
 487                 to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
 488         else if (from->sb_qflags & XFS_PQUOTA_ACCT)
 489                 to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
 490         else {
 491                 /*
 492                  * We can't rely on just the fields being logged to tell us
 493                  * that it is safe to write NULLFSINO - we should only do that
 494                  * if quotas are not actually enabled. Hence only write
 495                  * NULLFSINO if both in-core quota inodes are NULL.
 496                  */
 497                 if (from->sb_gquotino == NULLFSINO &&
 498                     from->sb_pquotino == NULLFSINO)
 499                         to->sb_gquotino = cpu_to_be64(NULLFSINO);
 500         }
 501
 502         to->sb_pquotino = 0;
 503 }
 504
 505 void
 506 xfs_sb_to_disk(
 507         struct xfs_dsb  *to,
 508         struct xfs_sb   *from)
 509 {
 510         xfs_sb_quota_to_disk(to, from);
 511
 512         to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
 513         to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
 514         to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
 515         to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
 516         to->sb_rextents = cpu_to_be64(from->sb_rextents);
 517         memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
 518         to->sb_logstart = cpu_to_be64(from->sb_logstart);
 519         to->sb_rootino = cpu_to_be64(from->sb_rootino);
 520         to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
 521         to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
 522         to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
 523         to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
 524         to->sb_agcount = cpu_to_be32(from->sb_agcount);
 525         to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
 526         to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
 527         to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
 528         to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
 529         to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
 530         to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
 531         memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
 532         to->sb_blocklog = from->sb_blocklog;
 533         to->sb_sectlog = from->sb_sectlog;
 534         to->sb_inodelog = from->sb_inodelog;
 535         to->sb_inopblog = from->sb_inopblog;
 536         to->sb_agblklog = from->sb_agblklog;
 537         to->sb_rextslog = from->sb_rextslog;
 538         to->sb_inprogress = from->sb_inprogress;
 539         to->sb_imax_pct = from->sb_imax_pct;
 540         to->sb_icount = cpu_to_be64(from->sb_icount);
 541         to->sb_ifree = cpu_to_be64(from->sb_ifree);
 542         to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
 543         to->sb_frextents = cpu_to_be64(from->sb_frextents);
 544
 545         to->sb_flags = from->sb_flags;
 546         to->sb_shared_vn = from->sb_shared_vn;
 547         to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
 548         to->sb_unit = cpu_to_be32(from->sb_unit);
 549         to->sb_width = cpu_to_be32(from->sb_width);
 550         to->sb_dirblklog = from->sb_dirblklog;
 551         to->sb_logsectlog = from->sb_logsectlog;
 552         to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
 553         to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
 554
 555         /*
 556          * We need to ensure that bad_features2 always matches features2.
 557          * Hence we enforce that here rather than having to remember to do it
 558          * everywhere else that updates features2.
 559          */
 560         from->sb_bad_features2 = from->sb_features2;
 561         to->sb_features2 = cpu_to_be32(from->sb_features2);
 562         to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
 563
 564         if (xfs_sb_version_hascrc(from)) {
 565                 to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
 566                 to->sb_features_ro_compat =
 567                                 cpu_to_be32(from->sb_features_ro_compat);
 568                 to->sb_features_incompat =
 569                                 cpu_to_be32(from->sb_features_incompat);
 570                 to->sb_features_log_incompat =
 571                                 cpu_to_be32(from->sb_features_log_incompat);
 572                 to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
 573                 to->sb_lsn = cpu_to_be64(from->sb_lsn);
 574                 if (xfs_sb_version_hasmetauuid(from))
 575                         uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
 576         }
 577 }
 578
 579 static int
 580 xfs_sb_verify(
 581         struct xfs_buf  *bp,
 582         bool            check_version)
 583 {
 584         struct xfs_mount *mp = bp->b_target->bt_mount;
 585         struct xfs_sb   sb;
 586
 587         /*
 588          * Use call variant which doesn't convert quota flags from disk
 589          * format, because xfs_mount_validate_sb checks the on-disk flags.
 590          */
 591         __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
 592
 593         /*
 594          * Only check the in progress field for the primary superblock as
 595          * mkfs.xfs doesn't clear it from secondary superblocks.
 596          */
 597         return xfs_mount_validate_sb(mp, &sb,
 598                                      bp->b_maps[0].bm_bn == XFS_SB_DADDR,
 599                                      check_version);
 600 }
 601
 602 /*
 603  * If the superblock has the CRC feature bit set or the CRC field is non-null,
 604  * check that the CRC is valid.  We check the CRC field is non-null because a
 605  * single bit error could clear the feature bit and unused parts of the
 606  * superblock are supposed to be zero. Hence a non-null crc field indicates that
 607  * we've potentially lost a feature bit and we should check it anyway.
 608  *
 609  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
 610  * last field in V4 secondary superblocks.  So for secondary superblocks,
 611  * we are more forgiving, and ignore CRC failures if the primary doesn't
 612  * indicate that the fs version is V5.
 613  */
 614 static void
 615 xfs_sb_read_verify(
 616         struct xfs_buf  *bp)
 617 {
 618         struct xfs_mount *mp = bp->b_target->bt_mount;
 619         struct xfs_dsb  *dsb = XFS_BUF_TO_SBP(bp);
 620         int             error;
 621
 622         /*
 623          * open code the version check to avoid needing to convert the entire
 624          * superblock from disk order just to check the version number
 625          */
 626         if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
 627             (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
 628                                                 XFS_SB_VERSION_5) ||
 629              dsb->sb_crc != 0)) {
 630
 631                 if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
 632                         /* Only fail bad secondaries on a known V5 filesystem */
 633                         if (bp->b_bn == XFS_SB_DADDR ||
 634                             xfs_sb_version_hascrc(&mp->m_sb)) {
 635                                 error = -EFSBADCRC;
 636                                 goto out_error;
 637                         }
 638                 }
 639         }
 640         error = xfs_sb_verify(bp, true);
 641
 642 out_error:
 643         if (error) {
 644                 xfs_buf_ioerror(bp, error);
 645                 if (error == -EFSCORRUPTED || error == -EFSBADCRC)
 646                         xfs_verifier_error(bp);
 647         }
 648 }
 649
 650 /*
 651  * We may be probed for a filesystem match, so we may not want to emit
 652  * messages when the superblock buffer is not actually an XFS superblock.
 653  * If we find an XFS superblock, then run a normal, noisy mount because we are
 654  * really going to mount it and want to know about errors.
 655  */
 656 static void
 657 xfs_sb_quiet_read_verify(
 658         struct xfs_buf  *bp)
 659 {
 660         struct xfs_dsb  *dsb = XFS_BUF_TO_SBP(bp);
 661
 662         if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
 663                 /* XFS filesystem, verify noisily! */
 664                 xfs_sb_read_verify(bp);
 665                 return;
 666         }
 667         /* quietly fail */
 668         xfs_buf_ioerror(bp, -EWRONGFS);
 669 }
 670
 671 static void
 672 xfs_sb_write_verify(
 673         struct xfs_buf          *bp)
 674 {
 675         struct xfs_mount        *mp = bp->b_target->bt_mount;
 676         struct xfs_buf_log_item *bip = bp->b_fspriv;
 677         int                     error;
 678
 679         error = xfs_sb_verify(bp, false);
 680         if (error) {
 681                 xfs_buf_ioerror(bp, error);
 682                 xfs_verifier_error(bp);
 683                 return;
 684         }
 685
 686         if (!xfs_sb_version_hascrc(&mp->m_sb))
 687                 return;
 688
 689         if (bip)
 690                 XFS_BUF_TO_SBP(bp)->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
 691
 692         xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
 693 }
 694
 695 const struct xfs_buf_ops xfs_sb_buf_ops = {
 696         .name = "xfs_sb",
 697         .verify_read = xfs_sb_read_verify,
 698         .verify_write = xfs_sb_write_verify,
 699 };
 700
 701 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
 702         .name = "xfs_sb_quiet",
 703         .verify_read = xfs_sb_quiet_read_verify,
 704         .verify_write = xfs_sb_write_verify,
 705 };
 706
 707 /*
 708  * xfs_mount_common
 709  *
 710  * Mount initialization code establishing various mount
 711  * fields from the superblock associated with the given
 712  * mount structure
 713  */
 714 void
 715 xfs_sb_mount_common(
 716         struct xfs_mount *mp,
 717         struct xfs_sb   *sbp)
 718 {
 719         mp->m_agfrotor = mp->m_agirotor = 0;
 720         spin_lock_init(&mp->m_agirotor_lock);
 721         mp->m_maxagi = mp->m_sb.sb_agcount;
 722         mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
 723         mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
 724         mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
 725         mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
 726         mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
 727         mp->m_blockmask = sbp->sb_blocksize - 1;
 728         mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
 729         mp->m_blockwmask = mp->m_blockwsize - 1;
 730
 731         mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
 732         mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
 733         mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
 734         mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
 735
 736         mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
 737         mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
 738         mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
 739         mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
 740
 741         mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
 742         mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
 743         mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
 744         mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
 745
 746         mp->m_rmap_mxr[0] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, 1);
 747         mp->m_rmap_mxr[1] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, 0);
 748         mp->m_rmap_mnr[0] = mp->m_rmap_mxr[0] / 2;
 749         mp->m_rmap_mnr[1] = mp->m_rmap_mxr[1] / 2;
 750
 751         mp->m_refc_mxr[0] = xfs_refcountbt_maxrecs(mp, sbp->sb_blocksize,
 752                         true);
 753         mp->m_refc_mxr[1] = xfs_refcountbt_maxrecs(mp, sbp->sb_blocksize,
 754                         false);
 755         mp->m_refc_mnr[0] = mp->m_refc_mxr[0] / 2;
 756         mp->m_refc_mnr[1] = mp->m_refc_mxr[1] / 2;
 757
 758         mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
 759         mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
 760                                         sbp->sb_inopblock);
 761         mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
 762
 763         if (sbp->sb_spino_align)
 764                 mp->m_ialloc_min_blks = sbp->sb_spino_align;
 765         else
 766                 mp->m_ialloc_min_blks = mp->m_ialloc_blks;
 767         mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
 768         mp->m_ag_max_usable = xfs_alloc_ag_max_usable(mp);
 769 }
 770
 771 /*
 772  * xfs_initialize_perag_data
 773  *
 774  * Read in each per-ag structure so we can count up the number of
 775  * allocated inodes, free inodes and used filesystem blocks as this
 776  * information is no longer persistent in the superblock. Once we have
 777  * this information, write it into the in-core superblock structure.
 778  */
 779 int
 780 xfs_initialize_perag_data(
 781         struct xfs_mount *mp,
 782         xfs_agnumber_t  agcount)
 783 {
 784         xfs_agnumber_t  index;
 785         xfs_perag_t     *pag;
 786         xfs_sb_t        *sbp = &mp->m_sb;
 787         uint64_t        ifree = 0;
 788         uint64_t        ialloc = 0;
 789         uint64_t        bfree = 0;
 790         uint64_t        bfreelst = 0;
 791         uint64_t        btree = 0;
 792         int             error;
 793
 794         for (index = 0; index < agcount; index++) {
 795                 /*
 796                  * read the agf, then the agi. This gets us
 797                  * all the information we need and populates the
 798                  * per-ag structures for us.
 799                  */
 800                 error = xfs_alloc_pagf_init(mp, NULL, index, 0);
 801                 if (error)
 802                         return error;
 803
 804                 error = xfs_ialloc_pagi_init(mp, NULL, index);
 805                 if (error)
 806                         return error;
 807                 pag = xfs_perag_get(mp, index);
 808                 ifree += pag->pagi_freecount;
 809                 ialloc += pag->pagi_count;
 810                 bfree += pag->pagf_freeblks;
 811                 bfreelst += pag->pagf_flcount;
 812                 btree += pag->pagf_btreeblks;
 813                 xfs_perag_put(pag);
 814         }
 815
 816         /* Overwrite incore superblock counters with just-read data */
 817         spin_lock(&mp->m_sb_lock);
 818         sbp->sb_ifree = ifree;
 819         sbp->sb_icount = ialloc;
 820         sbp->sb_fdblocks = bfree + bfreelst + btree;
 821         spin_unlock(&mp->m_sb_lock);
 822
 823         xfs_reinit_percpu_counters(mp);
 824
 825         return 0;
 826 }
 827
 828 /*
 829  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
 830  * into the superblock buffer to be logged.  It does not provide the higher
 831  * level of locking that is needed to protect the in-core superblock from
 832  * concurrent access.
 833  */
 834 void
 835 xfs_log_sb(
 836         struct xfs_trans        *tp)
 837 {
 838         struct xfs_mount        *mp = tp->t_mountp;
 839         struct xfs_buf          *bp = xfs_trans_getsb(tp, mp, 0);
 840
 841         mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount);
 842         mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree);
 843         mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
 844
 845         xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
 846         xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
 847         xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
 848 }
 849
 850 /*
 851  * xfs_sync_sb
 852  *
 853  * Sync the superblock to disk.
 854  *
 855  * Note that the caller is responsible for checking the frozen state of the
 856  * filesystem. This procedure uses the non-blocking transaction allocator and
 857  * thus will allow modifications to a frozen fs. This is required because this
 858  * code can be called during the process of freezing where use of the high-level
 859  * allocator would deadlock.
 860  */
 861 int
 862 xfs_sync_sb(
 863         struct xfs_mount        *mp,
 864         bool                    wait)
 865 {
 866         struct xfs_trans        *tp;
 867         int                     error;
 868
 869         error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0,
 870                         XFS_TRANS_NO_WRITECOUNT, &tp);
 871         if (error)
 872                 return error;
 873
 874         xfs_log_sb(tp);
 875         if (wait)
 876                 xfs_trans_set_sync(tp);
 877         return xfs_trans_commit(tp);
 878 }