libxfs/xfs_dquot_buf.c

   1 /*
   2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   3  * Copyright (c) 2013 Red Hat, Inc.
   4  * All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it would be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write the Free Software Foundation,
  17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19 #include "libxfs_priv.h"
  20 #include "xfs_fs.h"
  21 #include "xfs_shared.h"
  22 #include "xfs_format.h"
  23 #include "xfs_log_format.h"
  24 #include "xfs_trans_resv.h"
  25 #include "xfs_mount.h"
  26 #include "xfs_inode.h"
  27 #include "xfs_trans.h"
  28 #include "xfs_cksum.h"
  29 #include "xfs_trace.h"
  30 #include "xfs_quota_defs.h"
  31
  32 int
  33 xfs_calc_dquots_per_chunk(
  34         unsigned int            nbblks) /* basic block units */
  35 {
  36         ASSERT(nbblks > 0);
  37         return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
  38 }
  39
  40 /*
  41  * Do some primitive error checking on ondisk dquot data structures.
  42  *
  43  * The xfs_dqblk structure /contains/ the xfs_disk_dquot structure;
  44  * we verify them separately because at some points we have only the
  45  * smaller xfs_disk_dquot structure available.
  46  */
  47
  48 xfs_failaddr_t
  49 xfs_dquot_verify(
  50         struct xfs_mount *mp,
  51         xfs_disk_dquot_t *ddq,
  52         xfs_dqid_t       id,
  53         uint             type)    /* used only during quotacheck */
  54 {
  55         /*
  56          * We can encounter an uninitialized dquot buffer for 2 reasons:
  57          * 1. If we crash while deleting the quotainode(s), and those blks got
  58          *    used for user data. This is because we take the path of regular
  59          *    file deletion; however, the size field of quotainodes is never
  60          *    updated, so all the tricks that we play in itruncate_finish
  61          *    don't quite matter.
  62          *
  63          * 2. We don't play the quota buffers when there's a quotaoff logitem.
  64          *    But the allocation will be replayed so we'll end up with an
  65          *    uninitialized quota block.
  66          *
  67          * This is all fine; things are still consistent, and we haven't lost
  68          * any quota information. Just don't complain about bad dquot blks.
  69          */
  70         if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
  71                 return __this_address;
  72         if (ddq->d_version != XFS_DQUOT_VERSION)
  73                 return __this_address;
  74
  75         if (type && ddq->d_flags != type)
  76                 return __this_address;
  77         if (ddq->d_flags != XFS_DQ_USER &&
  78             ddq->d_flags != XFS_DQ_PROJ &&
  79             ddq->d_flags != XFS_DQ_GROUP)
  80                 return __this_address;
  81
  82         if (id != -1 && id != be32_to_cpu(ddq->d_id))
  83                 return __this_address;
  84
  85         if (!ddq->d_id)
  86                 return NULL;
  87
  88         if (ddq->d_blk_softlimit &&
  89             be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
  90             !ddq->d_btimer)
  91                 return __this_address;
  92
  93         if (ddq->d_ino_softlimit &&
  94             be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
  95             !ddq->d_itimer)
  96                 return __this_address;
  97
  98         if (ddq->d_rtb_softlimit &&
  99             be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
 100             !ddq->d_rtbtimer)
 101                 return __this_address;
 102
 103         return NULL;
 104 }
 105
 106 xfs_failaddr_t
 107 xfs_dqblk_verify(
 108         struct xfs_mount        *mp,
 109         struct xfs_dqblk        *dqb,
 110         xfs_dqid_t              id,
 111         uint                    type)   /* used only during quotacheck */
 112 {
 113         if (xfs_sb_version_hascrc(&mp->m_sb) &&
 114             !uuid_equal(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid))
 115                 return __this_address;
 116
 117         return xfs_dquot_verify(mp, &dqb->dd_diskdq, id, type);
 118 }
 119
 120 /*
 121  * Do some primitive error checking on ondisk dquot data structures.
 122  */
 123 int
 124 xfs_dqblk_repair(
 125         struct xfs_mount        *mp,
 126         struct xfs_dqblk        *dqb,
 127         xfs_dqid_t              id,
 128         uint                    type)
 129 {
 130         /*
 131          * Typically, a repair is only requested by quotacheck.
 132          */
 133         ASSERT(id != -1);
 134         memset(dqb, 0, sizeof(xfs_dqblk_t));
 135
 136         dqb->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 137         dqb->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 138         dqb->dd_diskdq.d_flags = type;
 139         dqb->dd_diskdq.d_id = cpu_to_be32(id);
 140
 141         if (xfs_sb_version_hascrc(&mp->m_sb)) {
 142                 uuid_copy(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid);
 143                 xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
 144                                  XFS_DQUOT_CRC_OFF);
 145         }
 146
 147         return 0;
 148 }
 149
 150 STATIC bool
 151 xfs_dquot_buf_verify_crc(
 152         struct xfs_mount        *mp,
 153         struct xfs_buf          *bp)
 154 {
 155         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 156         int                     ndquots;
 157         int                     i;
 158
 159         if (!xfs_sb_version_hascrc(&mp->m_sb))
 160                 return true;
 161
 162         /*
 163          * if we are in log recovery, the quota subsystem has not been
 164          * initialised so we have no quotainfo structure. In that case, we need
 165          * to manually calculate the number of dquots in the buffer.
 166          */
 167         if (mp->m_quotainfo)
 168                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 169         else
 170                 ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
 171
 172         for (i = 0; i < ndquots; i++, d++) {
 173                 if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
 174                                  XFS_DQUOT_CRC_OFF))
 175                         return false;
 176         }
 177         return true;
 178 }
 179
 180 STATIC xfs_failaddr_t
 181 xfs_dquot_buf_verify(
 182         struct xfs_mount        *mp,
 183         struct xfs_buf          *bp)
 184 {
 185         struct xfs_dqblk        *dqb = bp->b_addr;
 186         xfs_failaddr_t          fa;
 187         xfs_dqid_t              id = 0;
 188         int                     ndquots;
 189         int                     i;
 190
 191         /*
 192          * if we are in log recovery, the quota subsystem has not been
 193          * initialised so we have no quotainfo structure. In that case, we need
 194          * to manually calculate the number of dquots in the buffer.
 195          */
 196         if (mp->m_quotainfo)
 197                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 198         else
 199                 ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
 200
 201         /*
 202          * On the first read of the buffer, verify that each dquot is valid.
 203          * We don't know what the id of the dquot is supposed to be, just that
 204          * they should be increasing monotonically within the buffer. If the
 205          * first id is corrupt, then it will fail on the second dquot in the
 206          * buffer so corruptions could point to the wrong dquot in this case.
 207          */
 208         for (i = 0; i < ndquots; i++) {
 209                 struct xfs_disk_dquot   *ddq;
 210
 211                 ddq = &dqb[i].dd_diskdq;
 212
 213                 if (i == 0)
 214                         id = be32_to_cpu(ddq->d_id);
 215
 216                 fa = xfs_dqblk_verify(mp, &dqb[i], id + i, 0);
 217                 if (fa)
 218                         return fa;
 219         }
 220
 221         return NULL;
 222 }
 223
 224 static xfs_failaddr_t
 225 xfs_dquot_buf_verify_struct(
 226         struct xfs_buf          *bp)
 227 {
 228         struct xfs_mount        *mp = bp->b_target->bt_mount;
 229
 230         return xfs_dquot_buf_verify(mp, bp);
 231 }
 232
 233 static void
 234 xfs_dquot_buf_read_verify(
 235         struct xfs_buf          *bp)
 236 {
 237         struct xfs_mount        *mp = bp->b_target->bt_mount;
 238         xfs_failaddr_t          fa;
 239
 240         if (!xfs_dquot_buf_verify_crc(mp, bp))
 241                 xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 242         else {
 243                 fa = xfs_dquot_buf_verify(mp, bp);
 244                 if (fa)
 245                         xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
 246         }
 247 }
 248
 249 /*
 250  * readahead errors are silent and simply leave the buffer as !done so a real
 251  * read will then be run with the xfs_dquot_buf_ops verifier. See
 252  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
 253  * reporting the failure.
 254  */
 255 static void
 256 xfs_dquot_buf_readahead_verify(
 257         struct xfs_buf  *bp)
 258 {
 259         struct xfs_mount        *mp = bp->b_target->bt_mount;
 260
 261         if (!xfs_dquot_buf_verify_crc(mp, bp) ||
 262             xfs_dquot_buf_verify(mp, bp) != NULL) {
 263                 xfs_buf_ioerror(bp, -EIO);
 264                 bp->b_flags &= ~XBF_DONE;
 265         }
 266 }
 267
 268 /*
 269  * we don't calculate the CRC here as that is done when the dquot is flushed to
 270  * the buffer after the update is done. This ensures that the dquot in the
 271  * buffer always has an up-to-date CRC value.
 272  */
 273 static void
 274 xfs_dquot_buf_write_verify(
 275         struct xfs_buf          *bp)
 276 {
 277         struct xfs_mount        *mp = bp->b_target->bt_mount;
 278         xfs_failaddr_t          fa;
 279
 280         fa = xfs_dquot_buf_verify(mp, bp);
 281         if (fa)
 282                 xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
 283 }
 284
 285 const struct xfs_buf_ops xfs_dquot_buf_ops = {
 286         .name = "xfs_dquot",
 287         .verify_read = xfs_dquot_buf_read_verify,
 288         .verify_write = xfs_dquot_buf_write_verify,
 289         .verify_struct = xfs_dquot_buf_verify_struct,
 290 };
 291
 292 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
 293         .name = "xfs_dquot_ra",
 294         .verify_read = xfs_dquot_buf_readahead_verify,
 295         .verify_write = xfs_dquot_buf_write_verify,
 296 };