ldiskfs/kernel_patches/patches/rhel8.7/ext4-mballoc-extra-checks.patch

   1 Index: linux-4.18.0-80.1.2.el8_0/fs/ext4/ext4.h
   2 ===================================================================
   3 --- linux-4.18.0-80.1.2.el8_0.orig/fs/ext4/ext4.h
   4 +++ linux-4.18.0-80.1.2.el8_0/fs/ext4/ext4.h
   5 @@ -2881,6 +2881,7 @@ struct ext4_group_info {
   6         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
   7         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
   8         struct          list_head bb_prealloc_list;
   9 +       unsigned long   bb_prealloc_nr;
  10  #ifdef DOUBLE_CHECK
  11         void            *bb_bitmap;
  12  #endif
  13 Index: kernel-4.18.0-423.el8/fs/ext4/mballoc.c
  14 ===================================================================
  15 --- kernel-4.18.0-423.el8.orig/fs/ext4/mballoc.c
  16 +++ kernel-4.18.0-423.el8/fs/ext4/mballoc.c
  17 @@ -345,7 +345,7 @@ static const char * const ext4_groupinfo
  18         "ext4_groupinfo_64k", "ext4_groupinfo_128k"
  19  };
  20
  21 -static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
  22 +static int ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
  23                                         ext4_group_t group);
  24  static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
  25                                                 ext4_group_t group);
  26 @@ -769,7 +769,7 @@ mb_set_largest_free_order(struct super_b
  27  }
  28
  29  static noinline_for_stack
  30 -void ext4_mb_generate_buddy(struct super_block *sb,
  31 +int ext4_mb_generate_buddy(struct super_block *sb,
  32                                 void *buddy, void *bitmap, ext4_group_t group)
  33  {
  34         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
  35 @@ -813,6 +813,7 @@ void ext4_mb_generate_buddy(struct super
  36                 grp->bb_free = free;
  37                 ext4_mark_group_bitmap_corrupted(sb, group,
  38                                         EXT4_GROUP_INFO_BBITMAP_CORRUPT);
  39 +               return -EIO;
  40         }
  41         mb_set_largest_free_order(sb, grp);
  42
  43 @@ -823,6 +824,8 @@ void ext4_mb_generate_buddy(struct super
  44         sbi->s_mb_buddies_generated++;
  45         sbi->s_mb_generation_time += period;
  46         spin_unlock(&sbi->s_bal_lock);
  47 +
  48 +       return 0;
  49  }
  50
  51  static void mb_regenerate_buddy(struct ext4_buddy *e4b)
  52 @@ -943,7 +946,7 @@ static int ext4_mb_init_cache(struct pag
  53         }
  54
  55         first_block = page->index * blocks_per_page;
  56 -       for (i = 0; i < blocks_per_page; i++) {
  57 +       for (i = 0; i < blocks_per_page && err == 0; i++) {
  58                 group = (first_block + i) >> 1;
  59                 if (group >= ngroups)
  60                         break;
  61 @@ -987,7 +990,7 @@ static int ext4_mb_init_cache(struct pag
  62                         ext4_lock_group(sb, group);
  63                         /* init the buddy */
  64                         memset(data, 0xff, blocksize);
  65 -                       ext4_mb_generate_buddy(sb, data, incore, group);
  66 +                       err = ext4_mb_generate_buddy(sb, data, incore, group);
  67                         ext4_unlock_group(sb, group);
  68                         incore = NULL;
  69                 } else {
  70 @@ -1002,7 +1005,7 @@ static int ext4_mb_init_cache(struct pag
  71                         memcpy(data, bitmap, blocksize);
  72
  73                         /* mark all preallocated blks used in in-core bitmap */
  74 -                       ext4_mb_generate_from_pa(sb, data, group);
  75 +                       err = ext4_mb_generate_from_pa(sb, data, group);
  76                         ext4_mb_generate_from_freelist(sb, data, group);
  77                         ext4_unlock_group(sb, group);
  78
  79 @@ -1012,7 +1015,8 @@ static int ext4_mb_init_cache(struct pag
  80                         incore = data;
  81                 }
  82         }
  83 -       SetPageUptodate(page);
  84 +       if (likely(err == 0))
  85 +               SetPageUptodate(page);
  86
  87  out:
  88         if (bh) {
  89 @@ -2388,9 +2392,11 @@ static void *ext4_mb_seq_groups_next(str
  90  static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
  91  {
  92         struct super_block *sb = PDE_DATA(file_inode(seq->file));
  93 +       struct ext4_group_desc *gdp;
  94         ext4_group_t group = (ext4_group_t) ((unsigned long) v);
  95         int i;
  96         int err, buddy_loaded = 0;
  97 +       int free = 0;
  98         struct ext4_buddy e4b;
  99         struct ext4_group_info *grinfo;
 100         unsigned char blocksize_bits = min_t(unsigned char,
 101 @@ -2403,7 +2409,7 @@ static int ext4_mb_seq_groups_show(struc
 102
 103         group--;
 104         if (group == 0)
 105 -               seq_puts(seq, "#group: free  frags first ["
 106 +               seq_puts(seq, "#group: bfree gfree frags first pa    ["
 107                               " 2^0   2^1   2^2   2^3   2^4   2^5   2^6  "
 108                               " 2^7   2^8   2^9   2^10  2^11  2^12  2^13  ]\n");
 109
 110 @@ -2421,13 +2427,19 @@ static int ext4_mb_seq_groups_show(struc
 111                 buddy_loaded = 1;
 112         }
 113
 114 +       gdp = ext4_get_group_desc(sb, group, NULL);
 115 +       if (gdp != NULL)
 116 +               free = ext4_free_group_clusters(sb, gdp);
 117 +
 118         memcpy(&sg, ext4_get_group_info(sb, group), i);
 119
 120         if (buddy_loaded)
 121                 ext4_mb_unload_buddy(&e4b);
 122
 123 -       seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
 124 -                       sg.info.bb_fragments, sg.info.bb_first_free);
 125 +       seq_printf(seq, "#%-5lu: %-5u %-5u %-5u %-5u %-5lu [",
 126 +                       (long unsigned int)group, sg.info.bb_free, free,
 127 +                       sg.info.bb_fragments, sg.info.bb_first_free,
 128 +                       sg.info.bb_prealloc_nr);
 129         for (i = 0; i <= 13; i++)
 130                 seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ?
 131                                 sg.info.bb_counters[i] : 0);
 132 @@ -3743,22 +3755,71 @@ static void ext4_mb_generate_from_freeli
 133  }
 134
 135  /*
 136 + * check free blocks in bitmap match free block in group descriptor
 137 + * do this before taking preallocated blocks into account to be able
 138 + * to detect on-disk corruptions. The group lock should be hold by the
 139 + * caller.
 140 + */
 141 +int ext4_mb_check_ondisk_bitmap(struct super_block *sb, void *bitmap,
 142 +                               struct ext4_group_desc *gdp, int group)
 143 +{
 144 +       unsigned short max = EXT4_CLUSTERS_PER_GROUP(sb);
 145 +       unsigned short i, first, free = 0;
 146 +       unsigned short free_in_gdp = ext4_free_group_clusters(sb, gdp);
 147 +
 148 +       if (free_in_gdp == 0 && gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
 149 +               return 0;
 150 +
 151 +       i = mb_find_next_zero_bit(bitmap, max, 0);
 152 +
 153 +       while (i < max) {
 154 +               first = i;
 155 +               i = mb_find_next_bit(bitmap, max, i);
 156 +               if (i > max)
 157 +                       i = max;
 158 +               free += i - first;
 159 +               if (i < max)
 160 +                       i = mb_find_next_zero_bit(bitmap, max, i);
 161 +       }
 162 +
 163 +       if (free != free_in_gdp) {
 164 +               ext4_error(sb, "on-disk bitmap for group %d"
 165 +                       "corrupted: %u blocks free in bitmap, %u - in gd\n",
 166 +                       group, free, free_in_gdp);
 167 +               return -EIO;
 168 +       }
 169 +       return 0;
 170 +}
 171 +
 172 +/*
 173   * the function goes through all preallocation in this group and marks them
 174   * used in in-core bitmap. buddy must be generated from this bitmap
 175   * Need to be called with ext4 group lock held
 176   */
 177  static noinline_for_stack
 178 -void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
 179 +int ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
 180                                         ext4_group_t group)
 181  {
 182         struct ext4_group_info *grp = ext4_get_group_info(sb, group);
 183         struct ext4_prealloc_space *pa;
 184 +       struct ext4_group_desc *gdp;
 185         struct list_head *cur;
 186         ext4_group_t groupnr;
 187         ext4_grpblk_t start;
 188         int preallocated = 0;
 189 +       int skip = 0, count = 0;
 190 +       int err;
 191         int len;
 192
 193 +       gdp = ext4_get_group_desc(sb, group, NULL);
 194 +       if (gdp == NULL)
 195 +               return -EIO;
 196 +
 197 +       /* before applying preallocations, check bitmap consistency */
 198 +       err = ext4_mb_check_ondisk_bitmap(sb, bitmap, gdp, group);
 199 +       if (err)
 200 +               return err;
 201 +
 202         /* all form of preallocation discards first load group,
 203          * so the only competing code is preallocation use.
 204          * we don't need any locking here
 205 @@ -3774,13 +3835,23 @@ void ext4_mb_generate_from_pa(struct sup
 206                                              &groupnr, &start);
 207                 len = pa->pa_len;
 208                 spin_unlock(&pa->pa_lock);
 209 -               if (unlikely(len == 0))
 210 +               if (unlikely(len == 0)) {
 211 +                       skip++;
 212                         continue;
 213 +               }
 214                 BUG_ON(groupnr != group);
 215                 ext4_set_bits(bitmap, start, len);
 216                 preallocated += len;
 217 +               count++;
 218         }
 219 +       if (count + skip != grp->bb_prealloc_nr) {
 220 +               ext4_error(sb, "lost preallocations: "
 221 +                          "count %d, bb_prealloc_nr %lu, skip %d\n",
 222 +                          count, grp->bb_prealloc_nr, skip);
 223 +               return -EIO;
 224 +       }
 225         mb_debug(sb, "preallocated %d for group %u\n", preallocated, group);
 226 +       return 0;
 227  }
 228
 229  static void ext4_mb_pa_callback(struct rcu_head *head)
 230 @@ -3844,6 +3915,7 @@ static void ext4_mb_put_pa(struct ext4_a
 231          */
 232         ext4_lock_group(sb, grp);
 233         list_del(&pa->pa_group_list);
 234 +       ext4_get_group_info(sb, grp)->bb_prealloc_nr--;
 235         ext4_unlock_group(sb, grp);
 236
 237         spin_lock(pa->pa_obj_lock);
 238 @@ -3935,6 +4007,7 @@ ext4_mb_new_inode_pa(struct ext4_allocat
 239         pa->pa_inode = ac->ac_inode;
 240
 241         list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
 242 +       grp->bb_prealloc_nr++;
 243
 244         spin_lock(pa->pa_obj_lock);
 245         list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
 246 @@ -3989,6 +4062,7 @@ ext4_mb_new_group_pa(struct ext4_allocat
 247         pa->pa_inode = NULL;
 248
 249         list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
 250 +       grp->bb_prealloc_nr++;
 251
 252         /*
 253          * We will later add the new pa to the right bucket
 254 @@ -4153,6 +4227,8 @@ ext4_mb_discard_group_preallocations(str
 255
 256                 spin_unlock(&pa->pa_lock);
 257
 258 +               BUG_ON(grp->bb_prealloc_nr == 0);
 259 +               grp->bb_prealloc_nr--;
 260                 list_del(&pa->pa_group_list);
 261                 list_add(&pa->u.pa_tmp_list, &list);
 262         }
 263 @@ -4272,7 +4348,7 @@ repeat:
 264                 if (err) {
 265                         ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
 266                                        err, group);
 267 -                       continue;
 268 +                       return;
 269                 }
 270
 271                 bitmap_bh = ext4_read_block_bitmap(sb, group);
 272 @@ -4285,6 +4361,8 @@ repeat:
 273                 }
 274
 275                 ext4_lock_group(sb, group);
 276 +               BUG_ON(e4b.bd_info->bb_prealloc_nr == 0);
 277 +               e4b.bd_info->bb_prealloc_nr--;
 278                 list_del(&pa->pa_group_list);
 279                 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
 280                 ext4_unlock_group(sb, group);
 281 @@ -4578,6 +4656,7 @@ ext4_mb_discard_lg_preallocations(struct
 282                 }
 283                 ext4_lock_group(sb, group);
 284                 list_del(&pa->pa_group_list);
 285 +               ext4_get_group_info(sb, group)->bb_prealloc_nr--;
 286                 ext4_mb_release_group_pa(&e4b, pa);
 287                 ext4_unlock_group(sb, group);
 288
 289 Index: linux-4.18.0-80.1.2.el8_0/fs/ext4/mballoc.h
 290 ===================================================================
 291 --- linux-4.18.0-80.1.2.el8_0.orig/fs/ext4/mballoc.h
 292 +++ linux-4.18.0-80.1.2.el8_0/fs/ext4/mballoc.h
 293 @@ -70,7 +70,7 @@ do {                                                                  \
 294  /*
 295   * for which requests use 2^N search using buddies
 296   */
 297 -#define MB_DEFAULT_ORDER2_REQS         2
 298 +#define MB_DEFAULT_ORDER2_REQS         8
 299
 300  /*
 301   * default group prealloc size 512 blocks