root/fs/xfs/libxfs/xfs_dquot_buf.c

DEFINITIONS

1. xfs_calc_dquots_per_chunk
2. xfs_dquot_verify
3. xfs_dqblk_verify
4. xfs_dqblk_repair
5. xfs_dquot_buf_verify_crc
6. xfs_dquot_buf_verify
7. xfs_dquot_buf_verify_struct
8. xfs_dquot_buf_read_verify
9. xfs_dquot_buf_readahead_verify
10. xfs_dquot_buf_write_verify

   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 
  20 int
  21 xfs_calc_dquots_per_chunk(
  22         unsigned int            nbblks) /* basic block units */
  23 {
  24         ASSERT(nbblks > 0);
  25         return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
  26 }
  27 
  28 /*
  29  * Do some primitive error checking on ondisk dquot data structures.
  30  *
  31  * The xfs_dqblk structure /contains/ the xfs_disk_dquot structure;
  32  * we verify them separately because at some points we have only the
  33  * smaller xfs_disk_dquot structure available.
  34  */
  35 
  36 xfs_failaddr_t
  37 xfs_dquot_verify(
  38         struct xfs_mount *mp,
  39         xfs_disk_dquot_t *ddq,
  40         xfs_dqid_t       id,
  41         uint             type)    /* used only during quotacheck */
  42 {
  43         /*
  44          * We can encounter an uninitialized dquot buffer for 2 reasons:
  45          * 1. If we crash while deleting the quotainode(s), and those blks got
  46          *    used for user data. This is because we take the path of regular
  47          *    file deletion; however, the size field of quotainodes is never
  48          *    updated, so all the tricks that we play in itruncate_finish
  49          *    don't quite matter.
  50          *
  51          * 2. We don't play the quota buffers when there's a quotaoff logitem.
  52          *    But the allocation will be replayed so we'll end up with an
  53          *    uninitialized quota block.
  54          *
  55          * This is all fine; things are still consistent, and we haven't lost
  56          * any quota information. Just don't complain about bad dquot blks.
  57          */
  58         if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
  59                 return __this_address;
  60         if (ddq->d_version != XFS_DQUOT_VERSION)
  61                 return __this_address;
  62 
  63         if (type && ddq->d_flags != type)
  64                 return __this_address;
  65         if (ddq->d_flags != XFS_DQ_USER &&
  66             ddq->d_flags != XFS_DQ_PROJ &&
  67             ddq->d_flags != XFS_DQ_GROUP)
  68                 return __this_address;
  69 
  70         if (id != -1 && id != be32_to_cpu(ddq->d_id))
  71                 return __this_address;
  72 
  73         if (!ddq->d_id)
  74                 return NULL;
  75 
  76         if (ddq->d_blk_softlimit &&
  77             be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
  78             !ddq->d_btimer)
  79                 return __this_address;
  80 
  81         if (ddq->d_ino_softlimit &&
  82             be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
  83             !ddq->d_itimer)
  84                 return __this_address;
  85 
  86         if (ddq->d_rtb_softlimit &&
  87             be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
  88             !ddq->d_rtbtimer)
  89                 return __this_address;
  90 
  91         return NULL;
  92 }
  93 
  94 xfs_failaddr_t
  95 xfs_dqblk_verify(
  96         struct xfs_mount        *mp,
  97         struct xfs_dqblk        *dqb,
  98         xfs_dqid_t              id,
  99         uint                    type)   /* used only during quotacheck */
 100 {
 101         if (xfs_sb_version_hascrc(&mp->m_sb) &&
 102             !uuid_equal(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid))
 103                 return __this_address;
 104 
 105         return xfs_dquot_verify(mp, &dqb->dd_diskdq, id, type);
 106 }
 107 
 108 /*
 109  * Do some primitive error checking on ondisk dquot data structures.
 110  */
 111 void
 112 xfs_dqblk_repair(
 113         struct xfs_mount        *mp,
 114         struct xfs_dqblk        *dqb,
 115         xfs_dqid_t              id,
 116         uint                    type)
 117 {
 118         /*
 119          * Typically, a repair is only requested by quotacheck.
 120          */
 121         ASSERT(id != -1);
 122         memset(dqb, 0, sizeof(xfs_dqblk_t));
 123 
 124         dqb->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 125         dqb->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 126         dqb->dd_diskdq.d_flags = type;
 127         dqb->dd_diskdq.d_id = cpu_to_be32(id);
 128 
 129         if (xfs_sb_version_hascrc(&mp->m_sb)) {
 130                 uuid_copy(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid);
 131                 xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
 132                                  XFS_DQUOT_CRC_OFF);
 133         }
 134 }
 135 
 136 STATIC bool
 137 xfs_dquot_buf_verify_crc(
 138         struct xfs_mount        *mp,
 139         struct xfs_buf          *bp,
 140         bool                    readahead)
 141 {
 142         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 143         int                     ndquots;
 144         int                     i;
 145 
 146         if (!xfs_sb_version_hascrc(&mp->m_sb))
 147                 return true;
 148 
 149         /*
 150          * if we are in log recovery, the quota subsystem has not been
 151          * initialised so we have no quotainfo structure. In that case, we need
 152          * to manually calculate the number of dquots in the buffer.
 153          */
 154         if (mp->m_quotainfo)
 155                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 156         else
 157                 ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
 158 
 159         for (i = 0; i < ndquots; i++, d++) {
 160                 if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
 161                                  XFS_DQUOT_CRC_OFF)) {
 162                         if (!readahead)
 163                                 xfs_buf_verifier_error(bp, -EFSBADCRC, __func__,
 164                                         d, sizeof(*d), __this_address);
 165                         return false;
 166                 }
 167         }
 168         return true;
 169 }
 170 
 171 STATIC xfs_failaddr_t
 172 xfs_dquot_buf_verify(
 173         struct xfs_mount        *mp,
 174         struct xfs_buf          *bp,
 175         bool                    readahead)
 176 {
 177         struct xfs_dqblk        *dqb = bp->b_addr;
 178         xfs_failaddr_t          fa;
 179         xfs_dqid_t              id = 0;
 180         int                     ndquots;
 181         int                     i;
 182 
 183         /*
 184          * if we are in log recovery, the quota subsystem has not been
 185          * initialised so we have no quotainfo structure. In that case, we need
 186          * to manually calculate the number of dquots in the buffer.
 187          */
 188         if (mp->m_quotainfo)
 189                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 190         else
 191                 ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
 192 
 193         /*
 194          * On the first read of the buffer, verify that each dquot is valid.
 195          * We don't know what the id of the dquot is supposed to be, just that
 196          * they should be increasing monotonically within the buffer. If the
 197          * first id is corrupt, then it will fail on the second dquot in the
 198          * buffer so corruptions could point to the wrong dquot in this case.
 199          */
 200         for (i = 0; i < ndquots; i++) {
 201                 struct xfs_disk_dquot   *ddq;
 202 
 203                 ddq = &dqb[i].dd_diskdq;
 204 
 205                 if (i == 0)
 206                         id = be32_to_cpu(ddq->d_id);
 207 
 208                 fa = xfs_dqblk_verify(mp, &dqb[i], id + i, 0);
 209                 if (fa) {
 210                         if (!readahead)
 211                                 xfs_buf_verifier_error(bp, -EFSCORRUPTED,
 212                                         __func__, &dqb[i],
 213                                         sizeof(struct xfs_dqblk), fa);
 214                         return fa;
 215                 }
 216         }
 217 
 218         return NULL;
 219 }
 220 
 221 static xfs_failaddr_t
 222 xfs_dquot_buf_verify_struct(
 223         struct xfs_buf          *bp)
 224 {
 225         struct xfs_mount        *mp = bp->b_mount;
 226 
 227         return xfs_dquot_buf_verify(mp, bp, false);
 228 }
 229 
 230 static void
 231 xfs_dquot_buf_read_verify(
 232         struct xfs_buf          *bp)
 233 {
 234         struct xfs_mount        *mp = bp->b_mount;
 235 
 236         if (!xfs_dquot_buf_verify_crc(mp, bp, false))
 237                 return;
 238         xfs_dquot_buf_verify(mp, bp, false);
 239 }
 240 
 241 /*
 242  * readahead errors are silent and simply leave the buffer as !done so a real
 243  * read will then be run with the xfs_dquot_buf_ops verifier. See
 244  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
 245  * reporting the failure.
 246  */
 247 static void
 248 xfs_dquot_buf_readahead_verify(
 249         struct xfs_buf  *bp)
 250 {
 251         struct xfs_mount        *mp = bp->b_mount;
 252 
 253         if (!xfs_dquot_buf_verify_crc(mp, bp, true) ||
 254             xfs_dquot_buf_verify(mp, bp, true) != NULL) {
 255                 xfs_buf_ioerror(bp, -EIO);
 256                 bp->b_flags &= ~XBF_DONE;
 257         }
 258 }
 259 
 260 /*
 261  * we don't calculate the CRC here as that is done when the dquot is flushed to
 262  * the buffer after the update is done. This ensures that the dquot in the
 263  * buffer always has an up-to-date CRC value.
 264  */
 265 static void
 266 xfs_dquot_buf_write_verify(
 267         struct xfs_buf          *bp)
 268 {
 269         struct xfs_mount        *mp = bp->b_mount;
 270 
 271         xfs_dquot_buf_verify(mp, bp, false);
 272 }
 273 
 274 const struct xfs_buf_ops xfs_dquot_buf_ops = {
 275         .name = "xfs_dquot",
 276         .magic16 = { cpu_to_be16(XFS_DQUOT_MAGIC),
 277                      cpu_to_be16(XFS_DQUOT_MAGIC) },
 278         .verify_read = xfs_dquot_buf_read_verify,
 279         .verify_write = xfs_dquot_buf_write_verify,
 280         .verify_struct = xfs_dquot_buf_verify_struct,
 281 };
 282 
 283 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
 284         .name = "xfs_dquot_ra",
 285         .magic16 = { cpu_to_be16(XFS_DQUOT_MAGIC),
 286                      cpu_to_be16(XFS_DQUOT_MAGIC) },
 287         .verify_read = xfs_dquot_buf_readahead_verify,
 288         .verify_write = xfs_dquot_buf_write_verify,
 289 };