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 > 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         /*
 266          * Until this is fixed only page-sized or smaller data blocks work.
 267          */
 268         if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
 269                 xfs_warn(mp,
 270                 "File system with blocksize %d bytes. "
 271                 "Only pagesize (%ld) or less will currently work.",
 272                                 sbp->sb_blocksize, PAGE_SIZE);
 273                 return -ENOSYS;
 274         }
 275
 276         /*
 277          * Currently only very few inode sizes are supported.
 278          */
 279         switch (sbp->sb_inodesize) {
 280         case 256:
 281         case 512:
 282         case 1024:
 283         case 2048:
 284                 break;
 285         default:
 286                 xfs_warn(mp, "inode size of %d bytes not supported",
 287                                 sbp->sb_inodesize);
 288                 return -ENOSYS;
 289         }
 290
 291         if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
 292             xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
 293                 xfs_warn(mp,
 294                 "file system too large to be mounted on this system.");
 295                 return -EFBIG;
 296         }
 297
 298         if (check_inprogress && sbp->sb_inprogress) {
 299                 xfs_warn(mp, "Offline file system operation in progress!");
 300                 return -EFSCORRUPTED;
 301         }
 302         return 0;
 303 }
 304
 305 void
 306 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
 307 {
 308         /*
 309          * older mkfs doesn't initialize quota inodes to NULLFSINO. This
 310          * leads to in-core values having two different values for a quota
 311          * inode to be invalid: 0 and NULLFSINO. Change it to a single value
 312          * NULLFSINO.
 313          *
 314          * Note that this change affect only the in-core values. These
 315          * values are not written back to disk unless any quota information
 316          * is written to the disk. Even in that case, sb_pquotino field is
 317          * not written to disk unless the superblock supports pquotino.
 318          */
 319         if (sbp->sb_uquotino == 0)
 320                 sbp->sb_uquotino = NULLFSINO;
 321         if (sbp->sb_gquotino == 0)
 322                 sbp->sb_gquotino = NULLFSINO;
 323         if (sbp->sb_pquotino == 0)
 324                 sbp->sb_pquotino = NULLFSINO;
 325
 326         /*
 327          * We need to do these manipilations only if we are working
 328          * with an older version of on-disk superblock.
 329          */
 330         if (xfs_sb_version_has_pquotino(sbp))
 331                 return;
 332
 333         if (sbp->sb_qflags & XFS_OQUOTA_ENFD)
 334                 sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
 335                                         XFS_PQUOTA_ENFD : XFS_GQUOTA_ENFD;
 336         if (sbp->sb_qflags & XFS_OQUOTA_CHKD)
 337                 sbp->sb_qflags |= (sbp->sb_qflags & XFS_PQUOTA_ACCT) ?
 338                                         XFS_PQUOTA_CHKD : XFS_GQUOTA_CHKD;
 339         sbp->sb_qflags &= ~(XFS_OQUOTA_ENFD | XFS_OQUOTA_CHKD);
 340
 341         if (sbp->sb_qflags & XFS_PQUOTA_ACCT)  {
 342                 /*
 343                  * In older version of superblock, on-disk superblock only
 344                  * has sb_gquotino, and in-core superblock has both sb_gquotino
 345                  * and sb_pquotino. But, only one of them is supported at any
 346                  * point of time. So, if PQUOTA is set in disk superblock,
 347                  * copy over sb_gquotino to sb_pquotino.
 348                  */
 349                 sbp->sb_pquotino = sbp->sb_gquotino;
 350                 sbp->sb_gquotino = NULLFSINO;
 351         }
 352 }
 353
 354 static void
 355 __xfs_sb_from_disk(
 356         struct xfs_sb   *to,
 357         xfs_dsb_t       *from,
 358         bool            convert_xquota)
 359 {
 360         to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
 361         to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
 362         to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
 363         to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
 364         to->sb_rextents = be64_to_cpu(from->sb_rextents);
 365         memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
 366         to->sb_logstart = be64_to_cpu(from->sb_logstart);
 367         to->sb_rootino = be64_to_cpu(from->sb_rootino);
 368         to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
 369         to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
 370         to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
 371         to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
 372         to->sb_agcount = be32_to_cpu(from->sb_agcount);
 373         to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
 374         to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
 375         to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
 376         to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
 377         to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
 378         to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
 379         memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
 380         to->sb_blocklog = from->sb_blocklog;
 381         to->sb_sectlog = from->sb_sectlog;
 382         to->sb_inodelog = from->sb_inodelog;
 383         to->sb_inopblog = from->sb_inopblog;
 384         to->sb_agblklog = from->sb_agblklog;
 385         to->sb_rextslog = from->sb_rextslog;
 386         to->sb_inprogress = from->sb_inprogress;
 387         to->sb_imax_pct = from->sb_imax_pct;
 388         to->sb_icount = be64_to_cpu(from->sb_icount);
 389         to->sb_ifree = be64_to_cpu(from->sb_ifree);
 390         to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
 391         to->sb_frextents = be64_to_cpu(from->sb_frextents);
 392         to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
 393         to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
 394         to->sb_qflags = be16_to_cpu(from->sb_qflags);
 395         to->sb_flags = from->sb_flags;
 396         to->sb_shared_vn = from->sb_shared_vn;
 397         to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
 398         to->sb_unit = be32_to_cpu(from->sb_unit);
 399         to->sb_width = be32_to_cpu(from->sb_width);
 400         to->sb_dirblklog = from->sb_dirblklog;
 401         to->sb_logsectlog = from->sb_logsectlog;
 402         to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
 403         to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
 404         to->sb_features2 = be32_to_cpu(from->sb_features2);
 405         to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
 406         to->sb_features_compat = be32_to_cpu(from->sb_features_compat);
 407         to->sb_features_ro_compat = be32_to_cpu(from->sb_features_ro_compat);
 408         to->sb_features_incompat = be32_to_cpu(from->sb_features_incompat);
 409         to->sb_features_log_incompat =
 410                                 be32_to_cpu(from->sb_features_log_incompat);
 411         /* crc is only used on disk, not in memory; just init to 0 here. */
 412         to->sb_crc = 0;
 413         to->sb_spino_align = be32_to_cpu(from->sb_spino_align);
 414         to->sb_pquotino = be64_to_cpu(from->sb_pquotino);
 415         to->sb_lsn = be64_to_cpu(from->sb_lsn);
 416         /*
 417          * sb_meta_uuid is only on disk if it differs from sb_uuid and the
 418          * feature flag is set; if not set we keep it only in memory.
 419          */
 420         if (xfs_sb_version_hasmetauuid(to))
 421                 uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
 422         else
 423                 uuid_copy(&to->sb_meta_uuid, &from->sb_uuid);
 424         /* Convert on-disk flags to in-memory flags? */
 425         if (convert_xquota)
 426                 xfs_sb_quota_from_disk(to);
 427 }
 428
 429 void
 430 xfs_sb_from_disk(
 431         struct xfs_sb   *to,
 432         xfs_dsb_t       *from)
 433 {
 434         __xfs_sb_from_disk(to, from, true);
 435 }
 436
 437 static void
 438 xfs_sb_quota_to_disk(
 439         struct xfs_dsb  *to,
 440         struct xfs_sb   *from)
 441 {
 442         __uint16_t      qflags = from->sb_qflags;
 443
 444         to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
 445         if (xfs_sb_version_has_pquotino(from)) {
 446                 to->sb_qflags = cpu_to_be16(from->sb_qflags);
 447                 to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
 448                 to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
 449                 return;
 450         }
 451
 452         /*
 453          * The in-core version of sb_qflags do not have XFS_OQUOTA_*
 454          * flags, whereas the on-disk version does.  So, convert incore
 455          * XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
 456          */
 457         qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
 458                         XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
 459
 460         if (from->sb_qflags &
 461                         (XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
 462                 qflags |= XFS_OQUOTA_ENFD;
 463         if (from->sb_qflags &
 464                         (XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
 465                 qflags |= XFS_OQUOTA_CHKD;
 466         to->sb_qflags = cpu_to_be16(qflags);
 467
 468         /*
 469          * GQUOTINO and PQUOTINO cannot be used together in versions
 470          * of superblock that do not have pquotino. from->sb_flags
 471          * tells us which quota is active and should be copied to
 472          * disk. If neither are active, we should NULL the inode.
 473          *
 474          * In all cases, the separate pquotino must remain 0 because it
 475          * it beyond the "end" of the valid non-pquotino superblock.
 476          */
 477         if (from->sb_qflags & XFS_GQUOTA_ACCT)
 478                 to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
 479         else if (from->sb_qflags & XFS_PQUOTA_ACCT)
 480                 to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
 481         else {
 482                 /*
 483                  * We can't rely on just the fields being logged to tell us
 484                  * that it is safe to write NULLFSINO - we should only do that
 485                  * if quotas are not actually enabled. Hence only write
 486                  * NULLFSINO if both in-core quota inodes are NULL.
 487                  */
 488                 if (from->sb_gquotino == NULLFSINO &&
 489                     from->sb_pquotino == NULLFSINO)
 490                         to->sb_gquotino = cpu_to_be64(NULLFSINO);
 491         }
 492
 493         to->sb_pquotino = 0;
 494 }
 495
 496 void
 497 xfs_sb_to_disk(
 498         struct xfs_dsb  *to,
 499         struct xfs_sb   *from)
 500 {
 501         xfs_sb_quota_to_disk(to, from);
 502
 503         to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
 504         to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
 505         to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
 506         to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
 507         to->sb_rextents = cpu_to_be64(from->sb_rextents);
 508         memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
 509         to->sb_logstart = cpu_to_be64(from->sb_logstart);
 510         to->sb_rootino = cpu_to_be64(from->sb_rootino);
 511         to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
 512         to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
 513         to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
 514         to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
 515         to->sb_agcount = cpu_to_be32(from->sb_agcount);
 516         to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
 517         to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
 518         to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
 519         to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
 520         to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
 521         to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
 522         memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
 523         to->sb_blocklog = from->sb_blocklog;
 524         to->sb_sectlog = from->sb_sectlog;
 525         to->sb_inodelog = from->sb_inodelog;
 526         to->sb_inopblog = from->sb_inopblog;
 527         to->sb_agblklog = from->sb_agblklog;
 528         to->sb_rextslog = from->sb_rextslog;
 529         to->sb_inprogress = from->sb_inprogress;
 530         to->sb_imax_pct = from->sb_imax_pct;
 531         to->sb_icount = cpu_to_be64(from->sb_icount);
 532         to->sb_ifree = cpu_to_be64(from->sb_ifree);
 533         to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
 534         to->sb_frextents = cpu_to_be64(from->sb_frextents);
 535
 536         to->sb_flags = from->sb_flags;
 537         to->sb_shared_vn = from->sb_shared_vn;
 538         to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
 539         to->sb_unit = cpu_to_be32(from->sb_unit);
 540         to->sb_width = cpu_to_be32(from->sb_width);
 541         to->sb_dirblklog = from->sb_dirblklog;
 542         to->sb_logsectlog = from->sb_logsectlog;
 543         to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
 544         to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
 545
 546         /*
 547          * We need to ensure that bad_features2 always matches features2.
 548          * Hence we enforce that here rather than having to remember to do it
 549          * everywhere else that updates features2.
 550          */
 551         from->sb_bad_features2 = from->sb_features2;
 552         to->sb_features2 = cpu_to_be32(from->sb_features2);
 553         to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
 554
 555         if (xfs_sb_version_hascrc(from)) {
 556                 to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
 557                 to->sb_features_ro_compat =
 558                                 cpu_to_be32(from->sb_features_ro_compat);
 559                 to->sb_features_incompat =
 560                                 cpu_to_be32(from->sb_features_incompat);
 561                 to->sb_features_log_incompat =
 562                                 cpu_to_be32(from->sb_features_log_incompat);
 563                 to->sb_spino_align = cpu_to_be32(from->sb_spino_align);
 564                 to->sb_lsn = cpu_to_be64(from->sb_lsn);
 565                 if (xfs_sb_version_hasmetauuid(from))
 566                         uuid_copy(&to->sb_meta_uuid, &from->sb_meta_uuid);
 567         }
 568 }
 569
 570 static int
 571 xfs_sb_verify(
 572         struct xfs_buf  *bp,
 573         bool            check_version)
 574 {
 575         struct xfs_mount *mp = bp->b_target->bt_mount;
 576         struct xfs_sb   sb;
 577
 578         /*
 579          * Use call variant which doesn't convert quota flags from disk
 580          * format, because xfs_mount_validate_sb checks the on-disk flags.
 581          */
 582         __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
 583
 584         /*
 585          * Only check the in progress field for the primary superblock as
 586          * mkfs.xfs doesn't clear it from secondary superblocks.
 587          */
 588         return xfs_mount_validate_sb(mp, &sb,
 589                                      bp->b_maps[0].bm_bn == XFS_SB_DADDR,
 590                                      check_version);
 591 }
 592
 593 /*
 594  * If the superblock has the CRC feature bit set or the CRC field is non-null,
 595  * check that the CRC is valid.  We check the CRC field is non-null because a
 596  * single bit error could clear the feature bit and unused parts of the
 597  * superblock are supposed to be zero. Hence a non-null crc field indicates that
 598  * we've potentially lost a feature bit and we should check it anyway.
 599  *
 600  * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
 601  * last field in V4 secondary superblocks.  So for secondary superblocks,
 602  * we are more forgiving, and ignore CRC failures if the primary doesn't
 603  * indicate that the fs version is V5.
 604  */
 605 static void
 606 xfs_sb_read_verify(
 607         struct xfs_buf  *bp)
 608 {
 609         struct xfs_mount *mp = bp->b_target->bt_mount;
 610         struct xfs_dsb  *dsb = XFS_BUF_TO_SBP(bp);
 611         int             error;
 612
 613         /*
 614          * open code the version check to avoid needing to convert the entire
 615          * superblock from disk order just to check the version number
 616          */
 617         if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC) &&
 618             (((be16_to_cpu(dsb->sb_versionnum) & XFS_SB_VERSION_NUMBITS) ==
 619                                                 XFS_SB_VERSION_5) ||
 620              dsb->sb_crc != 0)) {
 621
 622                 if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
 623                         /* Only fail bad secondaries on a known V5 filesystem */
 624                         if (bp->b_bn == XFS_SB_DADDR ||
 625                             xfs_sb_version_hascrc(&mp->m_sb)) {
 626                                 error = -EFSBADCRC;
 627                                 goto out_error;
 628                         }
 629                 }
 630         }
 631         error = xfs_sb_verify(bp, true);
 632
 633 out_error:
 634         if (error) {
 635                 xfs_buf_ioerror(bp, error);
 636                 if (error == -EFSCORRUPTED || error == -EFSBADCRC)
 637                         xfs_verifier_error(bp);
 638         }
 639 }
 640
 641 /*
 642  * We may be probed for a filesystem match, so we may not want to emit
 643  * messages when the superblock buffer is not actually an XFS superblock.
 644  * If we find an XFS superblock, then run a normal, noisy mount because we are
 645  * really going to mount it and want to know about errors.
 646  */
 647 static void
 648 xfs_sb_quiet_read_verify(
 649         struct xfs_buf  *bp)
 650 {
 651         struct xfs_dsb  *dsb = XFS_BUF_TO_SBP(bp);
 652
 653         if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
 654                 /* XFS filesystem, verify noisily! */
 655                 xfs_sb_read_verify(bp);
 656                 return;
 657         }
 658         /* quietly fail */
 659         xfs_buf_ioerror(bp, -EWRONGFS);
 660 }
 661
 662 static void
 663 xfs_sb_write_verify(
 664         struct xfs_buf          *bp)
 665 {
 666         struct xfs_mount        *mp = bp->b_target->bt_mount;
 667         struct xfs_buf_log_item *bip = bp->b_fspriv;
 668         int                     error;
 669
 670         error = xfs_sb_verify(bp, false);
 671         if (error) {
 672                 xfs_buf_ioerror(bp, error);
 673                 xfs_verifier_error(bp);
 674                 return;
 675         }
 676
 677         if (!xfs_sb_version_hascrc(&mp->m_sb))
 678                 return;
 679
 680         if (bip)
 681                 XFS_BUF_TO_SBP(bp)->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
 682
 683         xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
 684 }
 685
 686 const struct xfs_buf_ops xfs_sb_buf_ops = {
 687         .name = "xfs_sb",
 688         .verify_read = xfs_sb_read_verify,
 689         .verify_write = xfs_sb_write_verify,
 690 };
 691
 692 const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
 693         .name = "xfs_sb_quiet",
 694         .verify_read = xfs_sb_quiet_read_verify,
 695         .verify_write = xfs_sb_write_verify,
 696 };
 697
 698 /*
 699  * xfs_mount_common
 700  *
 701  * Mount initialization code establishing various mount
 702  * fields from the superblock associated with the given
 703  * mount structure
 704  */
 705 void
 706 xfs_sb_mount_common(
 707         struct xfs_mount *mp,
 708         struct xfs_sb   *sbp)
 709 {
 710         mp->m_agfrotor = mp->m_agirotor = 0;
 711         spin_lock_init(&mp->m_agirotor_lock);
 712         mp->m_maxagi = mp->m_sb.sb_agcount;
 713         mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
 714         mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
 715         mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
 716         mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
 717         mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
 718         mp->m_blockmask = sbp->sb_blocksize - 1;
 719         mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
 720         mp->m_blockwmask = mp->m_blockwsize - 1;
 721
 722         mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
 723         mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
 724         mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
 725         mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
 726
 727         mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
 728         mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
 729         mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
 730         mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
 731
 732         mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
 733         mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
 734         mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
 735         mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
 736
 737         mp->m_rmap_mxr[0] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, 1);
 738         mp->m_rmap_mxr[1] = xfs_rmapbt_maxrecs(mp, sbp->sb_blocksize, 0);
 739         mp->m_rmap_mnr[0] = mp->m_rmap_mxr[0] / 2;
 740         mp->m_rmap_mnr[1] = mp->m_rmap_mxr[1] / 2;
 741
 742         mp->m_refc_mxr[0] = xfs_refcountbt_maxrecs(mp, sbp->sb_blocksize,
 743                         true);
 744         mp->m_refc_mxr[1] = xfs_refcountbt_maxrecs(mp, sbp->sb_blocksize,
 745                         false);
 746         mp->m_refc_mnr[0] = mp->m_refc_mxr[0] / 2;
 747         mp->m_refc_mnr[1] = mp->m_refc_mxr[1] / 2;
 748
 749         mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
 750         mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
 751                                         sbp->sb_inopblock);
 752         mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
 753
 754         if (sbp->sb_spino_align)
 755                 mp->m_ialloc_min_blks = sbp->sb_spino_align;
 756         else
 757                 mp->m_ialloc_min_blks = mp->m_ialloc_blks;
 758         mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
 759         mp->m_ag_max_usable = xfs_alloc_ag_max_usable(mp);
 760 }
 761
 762 /*
 763  * xfs_initialize_perag_data
 764  *
 765  * Read in each per-ag structure so we can count up the number of
 766  * allocated inodes, free inodes and used filesystem blocks as this
 767  * information is no longer persistent in the superblock. Once we have
 768  * this information, write it into the in-core superblock structure.
 769  */
 770 int
 771 xfs_initialize_perag_data(
 772         struct xfs_mount *mp,
 773         xfs_agnumber_t  agcount)
 774 {
 775         xfs_agnumber_t  index;
 776         xfs_perag_t     *pag;
 777         xfs_sb_t        *sbp = &mp->m_sb;
 778         uint64_t        ifree = 0;
 779         uint64_t        ialloc = 0;
 780         uint64_t        bfree = 0;
 781         uint64_t        bfreelst = 0;
 782         uint64_t        btree = 0;
 783         int             error;
 784
 785         for (index = 0; index < agcount; index++) {
 786                 /*
 787                  * read the agf, then the agi. This gets us
 788                  * all the information we need and populates the
 789                  * per-ag structures for us.
 790                  */
 791                 error = xfs_alloc_pagf_init(mp, NULL, index, 0);
 792                 if (error)
 793                         return error;
 794
 795                 error = xfs_ialloc_pagi_init(mp, NULL, index);
 796                 if (error)
 797                         return error;
 798                 pag = xfs_perag_get(mp, index);
 799                 ifree += pag->pagi_freecount;
 800                 ialloc += pag->pagi_count;
 801                 bfree += pag->pagf_freeblks;
 802                 bfreelst += pag->pagf_flcount;
 803                 btree += pag->pagf_btreeblks;
 804                 xfs_perag_put(pag);
 805         }
 806
 807         /* Overwrite incore superblock counters with just-read data */
 808         spin_lock(&mp->m_sb_lock);
 809         sbp->sb_ifree = ifree;
 810         sbp->sb_icount = ialloc;
 811         sbp->sb_fdblocks = bfree + bfreelst + btree;
 812         spin_unlock(&mp->m_sb_lock);
 813
 814         xfs_reinit_percpu_counters(mp);
 815
 816         return 0;
 817 }
 818
 819 /*
 820  * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
 821  * into the superblock buffer to be logged.  It does not provide the higher
 822  * level of locking that is needed to protect the in-core superblock from
 823  * concurrent access.
 824  */
 825 void
 826 xfs_log_sb(
 827         struct xfs_trans        *tp)
 828 {
 829         struct xfs_mount        *mp = tp->t_mountp;
 830         struct xfs_buf          *bp = xfs_trans_getsb(tp, mp, 0);
 831
 832         mp->m_sb.sb_icount = percpu_counter_sum(&mp->m_icount);
 833         mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree);
 834         mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
 835
 836         xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
 837         xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
 838         xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
 839 }
 840
 841 /*
 842  * xfs_sync_sb
 843  *
 844  * Sync the superblock to disk.
 845  *
 846  * Note that the caller is responsible for checking the frozen state of the
 847  * filesystem. This procedure uses the non-blocking transaction allocator and
 848  * thus will allow modifications to a frozen fs. This is required because this
 849  * code can be called during the process of freezing where use of the high-level
 850  * allocator would deadlock.
 851  */
 852 int
 853 xfs_sync_sb(
 854         struct xfs_mount        *mp,
 855         bool                    wait)
 856 {
 857         struct xfs_trans        *tp;
 858         int                     error;
 859
 860         error = xfs_trans_alloc(mp, &M_RES(mp)->tr_sb, 0, 0,
 861                         XFS_TRANS_NO_WRITECOUNT, &tp);
 862         if (error)
 863                 return error;
 864
 865         xfs_log_sb(tp);
 866         if (wait)
 867                 xfs_trans_set_sync(tp);
 868         return xfs_trans_commit(tp);
 869 }