fs/xfs/libxfs/xfs_dquot_buf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   4  * Copyright (c) 2013 Red Hat, Inc.
   5  * All Rights Reserved.
   6  */
   7 #include "xfs.h"
   8 #include "xfs_fs.h"
   9 #include "xfs_shared.h"
  10 #include "xfs_format.h"
  11 #include "xfs_log_format.h"
  12 #include "xfs_trans_resv.h"
  13 #include "xfs_mount.h"
  14 #include "xfs_inode.h"
  15 #include "xfs_quota.h"
  16 #include "xfs_trans.h"
  17 #include "xfs_qm.h"
  18 #include "xfs_error.h"
  19 #include "xfs_cksum.h"
  20 #include "xfs_trace.h"
  21
  22 int
  23 xfs_calc_dquots_per_chunk(
  24         unsigned int            nbblks) /* basic block units */
  25 {
  26         ASSERT(nbblks > 0);
  27         return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
  28 }
  29
  30 /*
  31  * Do some primitive error checking on ondisk dquot data structures.
  32  *
  33  * The xfs_dqblk structure /contains/ the xfs_disk_dquot structure;
  34  * we verify them separately because at some points we have only the
  35  * smaller xfs_disk_dquot structure available.
  36  */
  37
  38 xfs_failaddr_t
  39 xfs_dquot_verify(
  40         struct xfs_mount *mp,
  41         xfs_disk_dquot_t *ddq,
  42         xfs_dqid_t       id,
  43         uint             type)    /* used only during quotacheck */
  44 {
  45         /*
  46          * We can encounter an uninitialized dquot buffer for 2 reasons:
  47          * 1. If we crash while deleting the quotainode(s), and those blks got
  48          *    used for user data. This is because we take the path of regular
  49          *    file deletion; however, the size field of quotainodes is never
  50          *    updated, so all the tricks that we play in itruncate_finish
  51          *    don't quite matter.
  52          *
  53          * 2. We don't play the quota buffers when there's a quotaoff logitem.
  54          *    But the allocation will be replayed so we'll end up with an
  55          *    uninitialized quota block.
  56          *
  57          * This is all fine; things are still consistent, and we haven't lost
  58          * any quota information. Just don't complain about bad dquot blks.
  59          */
  60         if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
  61                 return __this_address;
  62         if (ddq->d_version != XFS_DQUOT_VERSION)
  63                 return __this_address;
  64
  65         if (type && ddq->d_flags != type)
  66                 return __this_address;
  67         if (ddq->d_flags != XFS_DQ_USER &&
  68             ddq->d_flags != XFS_DQ_PROJ &&
  69             ddq->d_flags != XFS_DQ_GROUP)
  70                 return __this_address;
  71
  72         if (id != -1 && id != be32_to_cpu(ddq->d_id))
  73                 return __this_address;
  74
  75         if (!ddq->d_id)
  76                 return NULL;
  77
  78         if (ddq->d_blk_softlimit &&
  79             be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
  80             !ddq->d_btimer)
  81                 return __this_address;
  82
  83         if (ddq->d_ino_softlimit &&
  84             be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
  85             !ddq->d_itimer)
  86                 return __this_address;
  87
  88         if (ddq->d_rtb_softlimit &&
  89             be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
  90             !ddq->d_rtbtimer)
  91                 return __this_address;
  92
  93         return NULL;
  94 }
  95
  96 xfs_failaddr_t
  97 xfs_dqblk_verify(
  98         struct xfs_mount        *mp,
  99         struct xfs_dqblk        *dqb,
 100         xfs_dqid_t              id,
 101         uint                    type)   /* used only during quotacheck */
 102 {
 103         if (xfs_sb_version_hascrc(&mp->m_sb) &&
 104             !uuid_equal(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid))
 105                 return __this_address;
 106
 107         return xfs_dquot_verify(mp, &dqb->dd_diskdq, id, type);
 108 }
 109
 110 /*
 111  * Do some primitive error checking on ondisk dquot data structures.
 112  */
 113 int
 114 xfs_dqblk_repair(
 115         struct xfs_mount        *mp,
 116         struct xfs_dqblk        *dqb,
 117         xfs_dqid_t              id,
 118         uint                    type)
 119 {
 120         /*
 121          * Typically, a repair is only requested by quotacheck.
 122          */
 123         ASSERT(id != -1);
 124         memset(dqb, 0, sizeof(xfs_dqblk_t));
 125
 126         dqb->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 127         dqb->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 128         dqb->dd_diskdq.d_flags = type;
 129         dqb->dd_diskdq.d_id = cpu_to_be32(id);
 130
 131         if (xfs_sb_version_hascrc(&mp->m_sb)) {
 132                 uuid_copy(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid);
 133                 xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
 134                                  XFS_DQUOT_CRC_OFF);
 135         }
 136
 137         return 0;
 138 }
 139
 140 STATIC bool
 141 xfs_dquot_buf_verify_crc(
 142         struct xfs_mount        *mp,
 143         struct xfs_buf          *bp,
 144         bool                    readahead)
 145 {
 146         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 147         int                     ndquots;
 148         int                     i;
 149
 150         if (!xfs_sb_version_hascrc(&mp->m_sb))
 151                 return true;
 152
 153         /*
 154          * if we are in log recovery, the quota subsystem has not been
 155          * initialised so we have no quotainfo structure. In that case, we need
 156          * to manually calculate the number of dquots in the buffer.
 157          */
 158         if (mp->m_quotainfo)
 159                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 160         else
 161                 ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
 162
 163         for (i = 0; i < ndquots; i++, d++) {
 164                 if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
 165                                  XFS_DQUOT_CRC_OFF)) {
 166                         if (!readahead)
 167                                 xfs_buf_verifier_error(bp, -EFSBADCRC, __func__,
 168                                         d, sizeof(*d), __this_address);
 169                         return false;
 170                 }
 171         }
 172         return true;
 173 }
 174
 175 STATIC xfs_failaddr_t
 176 xfs_dquot_buf_verify(
 177         struct xfs_mount        *mp,
 178         struct xfs_buf          *bp,
 179         bool                    readahead)
 180 {
 181         struct xfs_dqblk        *dqb = bp->b_addr;
 182         xfs_failaddr_t          fa;
 183         xfs_dqid_t              id = 0;
 184         int                     ndquots;
 185         int                     i;
 186
 187         /*
 188          * if we are in log recovery, the quota subsystem has not been
 189          * initialised so we have no quotainfo structure. In that case, we need
 190          * to manually calculate the number of dquots in the buffer.
 191          */
 192         if (mp->m_quotainfo)
 193                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 194         else
 195                 ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
 196
 197         /*
 198          * On the first read of the buffer, verify that each dquot is valid.
 199          * We don't know what the id of the dquot is supposed to be, just that
 200          * they should be increasing monotonically within the buffer. If the
 201          * first id is corrupt, then it will fail on the second dquot in the
 202          * buffer so corruptions could point to the wrong dquot in this case.
 203          */
 204         for (i = 0; i < ndquots; i++) {
 205                 struct xfs_disk_dquot   *ddq;
 206
 207                 ddq = &dqb[i].dd_diskdq;
 208
 209                 if (i == 0)
 210                         id = be32_to_cpu(ddq->d_id);
 211
 212                 fa = xfs_dqblk_verify(mp, &dqb[i], id + i, 0);
 213                 if (fa) {
 214                         if (!readahead)
 215                                 xfs_buf_verifier_error(bp, -EFSCORRUPTED,
 216                                         __func__, &dqb[i],
 217                                         sizeof(struct xfs_dqblk), fa);
 218                         return fa;
 219                 }
 220         }
 221
 222         return NULL;
 223 }
 224
 225 static xfs_failaddr_t
 226 xfs_dquot_buf_verify_struct(
 227         struct xfs_buf          *bp)
 228 {
 229         struct xfs_mount        *mp = bp->b_target->bt_mount;
 230
 231         return xfs_dquot_buf_verify(mp, bp, false);
 232 }
 233
 234 static void
 235 xfs_dquot_buf_read_verify(
 236         struct xfs_buf          *bp)
 237 {
 238         struct xfs_mount        *mp = bp->b_target->bt_mount;
 239
 240         if (!xfs_dquot_buf_verify_crc(mp, bp, false))
 241                 return;
 242         xfs_dquot_buf_verify(mp, bp, false);
 243 }
 244
 245 /*
 246  * readahead errors are silent and simply leave the buffer as !done so a real
 247  * read will then be run with the xfs_dquot_buf_ops verifier. See
 248  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
 249  * reporting the failure.
 250  */
 251 static void
 252 xfs_dquot_buf_readahead_verify(
 253         struct xfs_buf  *bp)
 254 {
 255         struct xfs_mount        *mp = bp->b_target->bt_mount;
 256
 257         if (!xfs_dquot_buf_verify_crc(mp, bp, true) ||
 258             xfs_dquot_buf_verify(mp, bp, true) != NULL) {
 259                 xfs_buf_ioerror(bp, -EIO);
 260                 bp->b_flags &= ~XBF_DONE;
 261         }
 262 }
 263
 264 /*
 265  * we don't calculate the CRC here as that is done when the dquot is flushed to
 266  * the buffer after the update is done. This ensures that the dquot in the
 267  * buffer always has an up-to-date CRC value.
 268  */
 269 static void
 270 xfs_dquot_buf_write_verify(
 271         struct xfs_buf          *bp)
 272 {
 273         struct xfs_mount        *mp = bp->b_target->bt_mount;
 274
 275         xfs_dquot_buf_verify(mp, bp, false);
 276 }
 277
 278 const struct xfs_buf_ops xfs_dquot_buf_ops = {
 279         .name = "xfs_dquot",
 280         .verify_read = xfs_dquot_buf_read_verify,
 281         .verify_write = xfs_dquot_buf_write_verify,
 282         .verify_struct = xfs_dquot_buf_verify_struct,
 283 };
 284
 285 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
 286         .name = "xfs_dquot_ra",
 287         .verify_read = xfs_dquot_buf_readahead_verify,
 288         .verify_write = xfs_dquot_buf_write_verify,
 289 };