e2fsck/pass4.c

   1 /*
   2  * pass4.c -- pass #4 of e2fsck: Check reference counts
   3  *
   4  * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  *
  11  * Pass 4 frees the following data structures:
  12  *      - A bitmap of which inodes are in bad blocks.   (inode_bb_map)
  13  *      - A bitmap of which inodes are imagic inodes.   (inode_imagic_map)
  14  *      - Ref counts for ea_inodes.                     (ea_inode_refs)
  15  */
  16
  17 #include "config.h"
  18 #include "e2fsck.h"
  19 #include "problem.h"
  20 #include <ext2fs/ext2_ext_attr.h>
  21
  22 /*
  23  * This routine is called when an inode is not connected to the
  24  * directory tree.
  25  *
  26  * This subroutine returns 1 then the caller shouldn't bother with the
  27  * rest of the pass 4 tests.
  28  */
  29 static int disconnect_inode(e2fsck_t ctx, ext2_ino_t i,
  30                             struct ext2_inode_large *inode)
  31 {
  32         ext2_filsys fs = ctx->fs;
  33         struct problem_context  pctx;
  34         __u32 eamagic = 0;
  35         int extra_size = 0;
  36
  37         e2fsck_read_inode_full(ctx, i, EXT2_INODE(inode),
  38                                EXT2_INODE_SIZE(fs->super),
  39                                "pass4: disconnect_inode");
  40         if (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE)
  41                 extra_size = inode->i_extra_isize;
  42
  43         clear_problem_context(&pctx);
  44         pctx.ino = i;
  45         pctx.inode = EXT2_INODE(inode);
  46
  47         if (EXT2_INODE_SIZE(fs->super) -EXT2_GOOD_OLD_INODE_SIZE -extra_size >0)
  48                 eamagic = *(__u32 *)(((char *)inode) +EXT2_GOOD_OLD_INODE_SIZE +
  49                                      extra_size);
  50         /*
  51          * Offer to delete any zero-length files that does not have
  52          * blocks.  If there is an EA block, it might have useful
  53          * information, so we won't prompt to delete it, but let it be
  54          * reconnected to lost+found.
  55          */
  56         if (!inode->i_blocks && eamagic != EXT2_EXT_ATTR_MAGIC &&
  57             (LINUX_S_ISREG(inode->i_mode) || LINUX_S_ISDIR(inode->i_mode))) {
  58                 if (fix_problem(ctx, PR_4_ZERO_LEN_INODE, &pctx)) {
  59                         e2fsck_clear_inode(ctx, i, EXT2_INODE(inode), 0,
  60                                            "disconnect_inode");
  61                         /*
  62                          * Fix up the bitmaps...
  63                          */
  64                         e2fsck_read_bitmaps(ctx);
  65                         ext2fs_inode_alloc_stats2(fs, i, -1,
  66                                                   LINUX_S_ISDIR(inode->i_mode));
  67                         quota_data_inodes(ctx->qctx, inode, i, -1);
  68                         return 0;
  69                 }
  70         }
  71
  72         /*
  73          * Prompt to reconnect.
  74          */
  75         if (fix_problem(ctx, PR_4_UNATTACHED_INODE, &pctx)) {
  76                 if (e2fsck_reconnect_file(ctx, i))
  77                         ext2fs_unmark_valid(fs);
  78         } else {
  79                 /*
  80                  * If we don't attach the inode, then skip the
  81                  * i_links_test since there's no point in trying to
  82                  * force i_links_count to zero.
  83                  */
  84                 ext2fs_unmark_valid(fs);
  85                 return 1;
  86         }
  87         return 0;
  88 }
  89
  90 static void check_ea_inode(e2fsck_t ctx, ext2_ino_t i,
  91                            struct ext2_inode_large *inode, __u16 *link_counted)
  92 {
  93         __u64 actual_refs = 0;
  94         __u64 ref_count;
  95
  96         /*
  97          * This function is called when link_counted is zero. So this may not
  98          * be an xattr inode at all. Return immediately if EA_INODE flag is not
  99          * set.
 100          */
 101         e2fsck_read_inode_full(ctx, i, EXT2_INODE(inode),
 102                                EXT2_INODE_SIZE(ctx->fs->super),
 103                                "pass4: check_ea_inode");
 104         if (!(inode->i_flags & EXT4_EA_INODE_FL))
 105                 return;
 106
 107         if (ctx->ea_inode_refs)
 108                 ea_refcount_fetch(ctx->ea_inode_refs, i, &actual_refs);
 109         if (!actual_refs)
 110                 return;
 111
 112         /*
 113          * There are some attribute references, link_counted is now considered
 114          * to be 1.
 115          */
 116         *link_counted = 1;
 117
 118         ref_count = ext2fs_get_ea_inode_ref(EXT2_INODE(inode));
 119
 120         /* Old Lustre-style xattr inodes do not have a stored refcount.
 121          * However, their i_ctime and i_atime should be the same.
 122          */
 123         if (ref_count != actual_refs && inode->i_ctime != inode->i_atime) {
 124                 struct problem_context pctx;
 125
 126                 clear_problem_context(&pctx);
 127                 pctx.ino = i;
 128                 pctx.num = ref_count;
 129                 pctx.num2 = actual_refs;
 130                 if (fix_problem(ctx, PR_4_EA_INODE_REF_COUNT, &pctx)) {
 131                         ext2fs_set_ea_inode_ref(EXT2_INODE(inode), actual_refs);
 132                         e2fsck_write_inode(ctx, i, EXT2_INODE(inode), "pass4");
 133                 }
 134         }
 135 }
 136
 137 void e2fsck_pass4(e2fsck_t ctx)
 138 {
 139         ext2_filsys fs = ctx->fs;
 140         ext2_ino_t      i;
 141         struct ext2_inode_large *inode;
 142         int inode_size = EXT2_INODE_SIZE(fs->super);
 143 #ifdef RESOURCE_TRACK
 144         struct resource_track   rtrack;
 145 #endif
 146         struct problem_context  pctx;
 147         __u16   link_count, link_counted;
 148         int dir_nlink_fs;
 149         char    *buf = 0;
 150         dgrp_t  group, maxgroup;
 151
 152         init_resource_track(&rtrack, ctx->fs->io);
 153
 154 #ifdef MTRACE
 155         mtrace_print("Pass 4");
 156 #endif
 157         /*
 158          * Since pass4 is mostly CPU bound, start readahead of bitmaps
 159          * ahead of pass 5 if we haven't already loaded them.
 160          */
 161         if (ctx->readahead_kb &&
 162             (fs->block_map == NULL || fs->inode_map == NULL))
 163                 e2fsck_readahead(fs, E2FSCK_READA_BBITMAP |
 164                                      E2FSCK_READA_IBITMAP,
 165                                  0, fs->group_desc_count);
 166
 167         clear_problem_context(&pctx);
 168
 169         if (!(ctx->options & E2F_OPT_PREEN))
 170                 fix_problem(ctx, PR_4_PASS_HEADER, &pctx);
 171
 172         dir_nlink_fs = ext2fs_has_feature_dir_nlink(fs->super);
 173
 174         group = 0;
 175         maxgroup = fs->group_desc_count;
 176         if (ctx->progress)
 177                 if ((ctx->progress)(ctx, 4, 0, maxgroup))
 178                         return;
 179
 180         inode = e2fsck_allocate_memory(ctx, inode_size, "scratch inode");
 181
 182         /* Protect loop from wrap-around if s_inodes_count maxed */
 183         for (i=1; i <= fs->super->s_inodes_count && i > 0; i++) {
 184                 int isdir;
 185
 186                 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
 187                         goto errout;
 188                 if ((i % fs->super->s_inodes_per_group) == 0) {
 189                         group++;
 190                         if (ctx->progress)
 191                                 if ((ctx->progress)(ctx, 4, group, maxgroup))
 192                                         goto errout;
 193                 }
 194                 if (i == quota_type2inum(PRJQUOTA, ctx->fs->super) ||
 195                     i == EXT2_BAD_INO ||
 196                     (i > EXT2_ROOT_INO && i < EXT2_FIRST_INODE(fs->super)))
 197                         continue;
 198                 if (!(ext2fs_test_inode_bitmap2(ctx->inode_used_map, i)) ||
 199                     (ctx->inode_imagic_map &&
 200                      ext2fs_test_inode_bitmap2(ctx->inode_imagic_map, i)) ||
 201                     (ctx->inode_bb_map &&
 202                      ext2fs_test_inode_bitmap2(ctx->inode_bb_map, i)))
 203                         continue;
 204                 ext2fs_icount_fetch(ctx->inode_link_info, i, &link_count);
 205                 ext2fs_icount_fetch(ctx->inode_count, i, &link_counted);
 206
 207                 if (link_counted == 0) {
 208                         /*
 209                          * link_counted is expected to be 0 for an ea_inode.
 210                          * check_ea_inode() will update link_counted if
 211                          * necessary.
 212                          */
 213                         check_ea_inode(ctx, i, inode, &link_counted);
 214                 }
 215
 216                 if (link_counted == 0) {
 217                         if (!buf)
 218                                 buf = e2fsck_allocate_memory(ctx,
 219                                      fs->blocksize, "bad_inode buffer");
 220                         if (e2fsck_process_bad_inode(ctx, 0, i, buf))
 221                                 continue;
 222                         if (disconnect_inode(ctx, i, inode))
 223                                 continue;
 224                         ext2fs_icount_fetch(ctx->inode_link_info, i,
 225                                             &link_count);
 226                         ext2fs_icount_fetch(ctx->inode_count, i,
 227                                             &link_counted);
 228                 }
 229                 isdir = ext2fs_test_inode_bitmap2(ctx->inode_dir_map, i);
 230                 if (isdir && (link_counted > EXT2_LINK_MAX)) {
 231                         if (!dir_nlink_fs &&
 232                             fix_problem(ctx, PR_4_DIR_NLINK_FEATURE, &pctx)) {
 233                                 ext2fs_set_feature_dir_nlink(fs->super);
 234                                 ext2fs_mark_super_dirty(fs);
 235                                 dir_nlink_fs = 1;
 236                         }
 237                         link_counted = 1;
 238                 }
 239                 if (link_counted != link_count) {
 240                         e2fsck_read_inode_full(ctx, i, EXT2_INODE(inode),
 241                                                inode_size, "pass4");
 242                         pctx.ino = i;
 243                         pctx.inode = EXT2_INODE(inode);
 244                         if ((link_count != inode->i_links_count) && !isdir &&
 245                             (inode->i_links_count <= EXT2_LINK_MAX)) {
 246                                 pctx.num = link_count;
 247                                 fix_problem(ctx,
 248                                             PR_4_INCONSISTENT_COUNT, &pctx);
 249                         }
 250                         pctx.num = link_counted;
 251                         /* i_link_count was previously exceeded, but no longer
 252                          * is, fix this but don't consider it an error */
 253                         if ((isdir && link_counted > 1 &&
 254                              (inode->i_flags & EXT2_INDEX_FL) &&
 255                              link_count == 1 && !(ctx->options & E2F_OPT_NO)) ||
 256                             fix_problem(ctx, PR_4_BAD_REF_COUNT, &pctx)) {
 257                                 inode->i_links_count = link_counted;
 258                                 e2fsck_write_inode_full(ctx, i,
 259                                                         EXT2_INODE(inode),
 260                                                         inode_size, "pass4");
 261                         }
 262                 }
 263         }
 264         ext2fs_free_icount(ctx->inode_link_info); ctx->inode_link_info = 0;
 265         ext2fs_free_icount(ctx->inode_count); ctx->inode_count = 0;
 266         ext2fs_free_inode_bitmap(ctx->inode_bb_map);
 267         ctx->inode_bb_map = 0;
 268         ea_refcount_free(ctx->ea_inode_refs);
 269         ctx->ea_inode_refs = 0;
 270         ext2fs_free_inode_bitmap(ctx->inode_imagic_map);
 271         ctx->inode_imagic_map = 0;
 272 errout:
 273         if (buf)
 274                 ext2fs_free_mem(&buf);
 275
 276         ext2fs_free_mem(&inode);
 277         print_resource_track(ctx, _("Pass 4"), &rtrack, ctx->fs->io);
 278 }
 279