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