fs/xfs/scrub/rtsummary.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <djwong@kernel.org>
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_trans_resv.h"
  11 #include "xfs_mount.h"
  12 #include "xfs_btree.h"
  13 #include "xfs_inode.h"
  14 #include "xfs_log_format.h"
  15 #include "xfs_trans.h"
  16 #include "xfs_rtbitmap.h"
  17 #include "xfs_bit.h"
  18 #include "xfs_bmap.h"
  19 #include "xfs_sb.h"
  20 #include "xfs_exchmaps.h"
  21 #include "xfs_rtgroup.h"
  22 #include "scrub/scrub.h"
  23 #include "scrub/common.h"
  24 #include "scrub/trace.h"
  25 #include "scrub/xfile.h"
  26 #include "scrub/repair.h"
  27 #include "scrub/tempexch.h"
  28 #include "scrub/rtsummary.h"
  29
  30 /*
  31  * Realtime Summary
  32  * ================
  33  *
  34  * We check the realtime summary by scanning the realtime bitmap file to create
  35  * a new summary file incore, and then we compare the computed version against
  36  * the ondisk version.  We use the 'xfile' functionality to store this
  37  * (potentially large) amount of data in pageable memory.
  38  */
  39
  40 /* Set us up to check the rtsummary file. */
  41 int
  42 xchk_setup_rtsummary(
  43         struct xfs_scrub        *sc)
  44 {
  45         struct xfs_mount        *mp = sc->mp;
  46         char                    *descr;
  47         struct xchk_rtsummary   *rts;
  48         int                     error;
  49
  50         if (xchk_need_intent_drain(sc))
  51                 xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
  52
  53         rts = kvzalloc(struct_size(rts, words, mp->m_blockwsize),
  54                         XCHK_GFP_FLAGS);
  55         if (!rts)
  56                 return -ENOMEM;
  57         sc->buf = rts;
  58
  59         error = xchk_rtgroup_init(sc, sc->sm->sm_agno, &sc->sr);
  60         if (error)
  61                 return error;
  62
  63         if (xchk_could_repair(sc)) {
  64                 error = xrep_setup_rtsummary(sc, rts);
  65                 if (error)
  66                         return error;
  67         }
  68
  69         /*
  70          * Create an xfile to construct a new rtsummary file.  The xfile allows
  71          * us to avoid pinning kernel memory for this purpose.
  72          */
  73         descr = xchk_xfile_descr(sc, "realtime summary file");
  74         error = xfile_create(descr, XFS_FSB_TO_B(mp, mp->m_rsumblocks),
  75                         &sc->xfile);
  76         kfree(descr);
  77         if (error)
  78                 return error;
  79
  80         error = xchk_trans_alloc(sc, rts->resblks);
  81         if (error)
  82                 return error;
  83
  84         error = xchk_install_live_inode(sc,
  85                         sc->sr.rtg->rtg_inodes[XFS_RTGI_SUMMARY]);
  86         if (error)
  87                 return error;
  88
  89         error = xchk_ino_dqattach(sc);
  90         if (error)
  91                 return error;
  92
  93         /*
  94          * Now that we've locked the rtbitmap and rtsummary, we can't race with
  95          * growfsrt trying to expand the summary or change the size of the rt
  96          * volume.  Hence it is safe to compute and check the geometry values.
  97          *
  98          * Note that there is no strict requirement for an exclusive lock on the
  99          * summary here, but to keep the locking APIs simple we lock both inodes
 100          * exclusively here.  If we ever start caring about running concurrent
 101          * fsmap with scrub this could be changed.
 102          */
 103         xchk_rtgroup_lock(&sc->sr, XFS_RTGLOCK_BITMAP);
 104         if (mp->m_sb.sb_rblocks) {
 105                 rts->rextents = xfs_blen_to_rtbxlen(mp, mp->m_sb.sb_rblocks);
 106                 rts->rbmblocks = xfs_rtbitmap_blockcount(mp);
 107                 rts->rsumblocks =
 108                         xfs_rtsummary_blockcount(mp, &rts->rsumlevels);
 109         }
 110
 111         return 0;
 112 }
 113
 114 /* Helper functions to record suminfo words in an xfile. */
 115
 116 static inline int
 117 xfsum_load(
 118         struct xfs_scrub        *sc,
 119         xfs_rtsumoff_t          sumoff,
 120         union xfs_suminfo_raw   *rawinfo)
 121 {
 122         return xfile_load(sc->xfile, rawinfo,
 123                         sizeof(union xfs_suminfo_raw),
 124                         sumoff << XFS_WORDLOG);
 125 }
 126
 127 static inline int
 128 xfsum_store(
 129         struct xfs_scrub        *sc,
 130         xfs_rtsumoff_t          sumoff,
 131         const union xfs_suminfo_raw rawinfo)
 132 {
 133         return xfile_store(sc->xfile, &rawinfo,
 134                         sizeof(union xfs_suminfo_raw),
 135                         sumoff << XFS_WORDLOG);
 136 }
 137
 138 inline int
 139 xfsum_copyout(
 140         struct xfs_scrub        *sc,
 141         xfs_rtsumoff_t          sumoff,
 142         union xfs_suminfo_raw   *rawinfo,
 143         unsigned int            nr_words)
 144 {
 145         return xfile_load(sc->xfile, rawinfo, nr_words << XFS_WORDLOG,
 146                         sumoff << XFS_WORDLOG);
 147 }
 148
 149 static inline xfs_suminfo_t
 150 xchk_rtsum_inc(
 151         struct xfs_mount        *mp,
 152         union xfs_suminfo_raw   *v)
 153 {
 154         if (xfs_has_rtgroups(mp)) {
 155                 be32_add_cpu(&v->rtg, 1);
 156                 return be32_to_cpu(v->rtg);
 157         }
 158
 159         v->old += 1;
 160         return v->old;
 161 }
 162
 163 /* Update the summary file to reflect the free extent that we've accumulated. */
 164 STATIC int
 165 xchk_rtsum_record_free(
 166         struct xfs_rtgroup              *rtg,
 167         struct xfs_trans                *tp,
 168         const struct xfs_rtalloc_rec    *rec,
 169         void                            *priv)
 170 {
 171         struct xfs_mount                *mp = rtg_mount(rtg);
 172         struct xfs_scrub                *sc = priv;
 173         xfs_fileoff_t                   rbmoff;
 174         xfs_rtblock_t                   rtbno;
 175         xfs_filblks_t                   rtlen;
 176         xfs_rtsumoff_t                  offs;
 177         unsigned int                    lenlog;
 178         union xfs_suminfo_raw           v;
 179         xfs_suminfo_t                   value;
 180         int                             error = 0;
 181
 182         if (xchk_should_terminate(sc, &error))
 183                 return error;
 184
 185         /* Compute the relevant location in the rtsum file. */
 186         rbmoff = xfs_rtx_to_rbmblock(mp, rec->ar_startext);
 187         lenlog = xfs_highbit64(rec->ar_extcount);
 188         offs = xfs_rtsumoffs(mp, lenlog, rbmoff);
 189
 190         rtbno = xfs_rtx_to_rtb(rtg, rec->ar_startext);
 191         rtlen = xfs_rtxlen_to_extlen(mp, rec->ar_extcount);
 192
 193         if (!xfs_verify_rtbext(mp, rtbno, rtlen)) {
 194                 xchk_ino_xref_set_corrupt(sc,
 195                                 rtg->rtg_inodes[XFS_RTGI_BITMAP]->i_ino);
 196                 return -EFSCORRUPTED;
 197         }
 198
 199         /* Bump the summary count. */
 200         error = xfsum_load(sc, offs, &v);
 201         if (error)
 202                 return error;
 203
 204         value = xchk_rtsum_inc(sc->mp, &v);
 205         trace_xchk_rtsum_record_free(mp, rec->ar_startext, rec->ar_extcount,
 206                         lenlog, offs, value);
 207
 208         return xfsum_store(sc, offs, v);
 209 }
 210
 211 /* Compute the realtime summary from the realtime bitmap. */
 212 STATIC int
 213 xchk_rtsum_compute(
 214         struct xfs_scrub        *sc)
 215 {
 216         struct xfs_mount        *mp = sc->mp;
 217         struct xfs_rtgroup      *rtg = sc->sr.rtg;
 218
 219         /* If the bitmap size doesn't match the computed size, bail. */
 220         if (XFS_FSB_TO_B(mp, xfs_rtbitmap_blockcount(mp)) !=
 221             rtg->rtg_inodes[XFS_RTGI_BITMAP]->i_disk_size)
 222                 return -EFSCORRUPTED;
 223
 224         return xfs_rtalloc_query_all(rtg, sc->tp, xchk_rtsum_record_free, sc);
 225 }
 226
 227 /* Compare the rtsummary file against the one we computed. */
 228 STATIC int
 229 xchk_rtsum_compare(
 230         struct xfs_scrub        *sc)
 231 {
 232         struct xfs_bmbt_irec    map;
 233         struct xfs_iext_cursor  icur;
 234
 235         struct xfs_mount        *mp = sc->mp;
 236         struct xfs_inode        *ip = sc->ip;
 237         struct xchk_rtsummary   *rts = sc->buf;
 238         xfs_fileoff_t           off = 0;
 239         xfs_fileoff_t           endoff;
 240         xfs_rtsumoff_t          sumoff = 0;
 241         int                     error = 0;
 242
 243         rts->args.mp = mp;
 244         rts->args.tp = sc->tp;
 245         rts->args.rtg = sc->sr.rtg;
 246
 247         /* Mappings may not cross or lie beyond EOF. */
 248         endoff = XFS_B_TO_FSB(mp, ip->i_disk_size);
 249         if (xfs_iext_lookup_extent(ip, &ip->i_df, endoff, &icur, &map)) {
 250                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, endoff);
 251                 return 0;
 252         }
 253
 254         while (off < endoff) {
 255                 int             nmap = 1;
 256
 257                 if (xchk_should_terminate(sc, &error))
 258                         return error;
 259                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 260                         return 0;
 261
 262                 /* Make sure we have a written extent. */
 263                 error = xfs_bmapi_read(ip, off, endoff - off, &map, &nmap,
 264                                 XFS_DATA_FORK);
 265                 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
 266                         return error;
 267
 268                 if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) {
 269                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
 270                         return 0;
 271                 }
 272
 273                 off += map.br_blockcount;
 274         }
 275
 276         for (off = 0; off < endoff; off++) {
 277                 union xfs_suminfo_raw   *ondisk_info;
 278
 279                 /* Read a block's worth of ondisk rtsummary file. */
 280                 error = xfs_rtsummary_read_buf(&rts->args, off);
 281                 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
 282                         return error;
 283
 284                 /* Read a block's worth of computed rtsummary file. */
 285                 error = xfsum_copyout(sc, sumoff, rts->words, mp->m_blockwsize);
 286                 if (error) {
 287                         xfs_rtbuf_cache_relse(&rts->args);
 288                         return error;
 289                 }
 290
 291                 ondisk_info = xfs_rsumblock_infoptr(&rts->args, 0);
 292                 if (memcmp(ondisk_info, rts->words,
 293                                         mp->m_blockwsize << XFS_WORDLOG) != 0) {
 294                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
 295                         xfs_rtbuf_cache_relse(&rts->args);
 296                         return error;
 297                 }
 298
 299                 xfs_rtbuf_cache_relse(&rts->args);
 300                 sumoff += mp->m_blockwsize;
 301         }
 302
 303         return 0;
 304 }
 305
 306 /* Scrub the realtime summary. */
 307 int
 308 xchk_rtsummary(
 309         struct xfs_scrub        *sc)
 310 {
 311         struct xfs_mount        *mp = sc->mp;
 312         struct xfs_rtgroup      *rtg = sc->sr.rtg;
 313         struct xfs_inode        *rbmip = rtg->rtg_inodes[XFS_RTGI_BITMAP];
 314         struct xfs_inode        *rsumip = rtg->rtg_inodes[XFS_RTGI_SUMMARY];
 315         struct xchk_rtsummary   *rts = sc->buf;
 316         int                     error;
 317
 318         /* Is sb_rextents correct? */
 319         if (mp->m_sb.sb_rextents != rts->rextents) {
 320                 xchk_ino_set_corrupt(sc, rbmip->i_ino);
 321                 return 0;
 322         }
 323
 324         /* Is m_rsumlevels correct? */
 325         if (mp->m_rsumlevels != rts->rsumlevels) {
 326                 xchk_ino_set_corrupt(sc, rsumip->i_ino);
 327                 return 0;
 328         }
 329
 330         /* Is m_rsumsize correct? */
 331         if (mp->m_rsumblocks != rts->rsumblocks) {
 332                 xchk_ino_set_corrupt(sc, rsumip->i_ino);
 333                 return 0;
 334         }
 335
 336         /* The summary file length must be aligned to an fsblock. */
 337         if (rsumip->i_disk_size & mp->m_blockmask) {
 338                 xchk_ino_set_corrupt(sc, rsumip->i_ino);
 339                 return 0;
 340         }
 341
 342         /*
 343          * Is the summary file itself large enough to handle the rt volume?
 344          * growfsrt expands the summary file before updating sb_rextents, so
 345          * the file can be larger than rsumsize.
 346          */
 347         if (rsumip->i_disk_size < XFS_FSB_TO_B(mp, rts->rsumblocks)) {
 348                 xchk_ino_set_corrupt(sc, rsumip->i_ino);
 349                 return 0;
 350         }
 351
 352         /* Invoke the fork scrubber. */
 353         error = xchk_metadata_inode_forks(sc);
 354         if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
 355                 return error;
 356
 357         /* Construct the new summary file from the rtbitmap. */
 358         error = xchk_rtsum_compute(sc);
 359         if (error == -EFSCORRUPTED) {
 360                 /*
 361                  * EFSCORRUPTED means the rtbitmap is corrupt, which is an xref
 362                  * error since we're checking the summary file.
 363                  */
 364                 xchk_ino_set_corrupt(sc, rbmip->i_ino);
 365                 return 0;
 366         }
 367         if (error)
 368                 return error;
 369
 370         /* Does the computed summary file match the actual rtsummary file? */
 371         return xchk_rtsum_compare(sc);
 372 }