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