ldiskfs/kernel_patches/patches/rhel7.6/ext4-prealloc.patch

   1 commit d8d8fd9192a54c7b8caef8cca9b7a1eb5e5e3298
   2 Author: Alex Zhuravlev <alex.zhuravlev@sun.com>
   3 AuthorDate: Thu Oct 23 10:02:19 2008 +0000
   4
   5 Subject: ext4: support for tunable preallocation window
   6 Add support for tunable preallocation window and new tunables
   7 for large/small requests.
   8
   9 Bugzilla-ID: b=12800
  10 Signed-off-by: Alex Zhuravlev <alex.zhuravlev@sun.com>
  11 Reviewed-by: Kalpak Shah <kalpak@clusterfs.com>
  12 Reviewed-by: Andreas Dilger <andreas.dilger@sun.com>
  13
  14 Index: linux-stage/fs/ext4/ext4.h
  15 ===================================================================
  16 --- linux-stage.orig/fs/ext4/ext4.h
  17 +++ linux-stage/fs/ext4/ext4.h
  18 @@ -1242,6 +1242,8 @@ struct ext4_super_block {
  19  #define EXT4_MF_MNTDIR_SAMPLED 0x0001
  20  #define EXT4_MF_FS_ABORTED     0x0002  /* Fatal error detected */
  21
  22 +#define EXT4_MAX_PREALLOC_TABLE        64
  23 +
  24  /*
  25   * fourth extended-fs super-block data in memory
  26   */
  27 @@ -1331,11 +1333,13 @@ struct ext4_sb_info {
  28
  29         /* tunables */
  30         unsigned long s_stripe;
  31 -       unsigned int s_mb_stream_request;
  32 +       unsigned long s_mb_small_req;
  33 +       unsigned long s_mb_large_req;
  34         unsigned int s_mb_max_to_scan;
  35         unsigned int s_mb_min_to_scan;
  36         unsigned int s_mb_stats;
  37         unsigned int s_mb_order2_reqs;
  38 +       unsigned long *s_mb_prealloc_table;
  39         unsigned int s_mb_group_prealloc;
  40         unsigned int s_max_dir_size_kb;
  41         /* where last allocation was done - for stream allocation */
  42 Index: linux-stage/fs/ext4/mballoc.c
  43 ===================================================================
  44 --- linux-stage.orig/fs/ext4/mballoc.c
  45 +++ linux-stage/fs/ext4/mballoc.c
  46 @@ -2303,6 +2303,102 @@ static const struct seq_operations ext4_
  47         .show   = ext4_mb_seq_groups_show,
  48  };
  49
  50 +#define EXT4_MB_PREALLOC_TABLE          "prealloc_table"
  51 +
  52 +static int ext4_mb_check_and_update_prealloc(struct ext4_sb_info *sbi,
  53 +                                                char *str, size_t cnt,
  54 +                                                int update)
  55 +{
  56 +       unsigned long value;
  57 +       unsigned long prev = 0;
  58 +       char *cur;
  59 +       char *next;
  60 +       char *end;
  61 +       int num = 0;
  62 +
  63 +       cur = str;
  64 +       end = str + cnt;
  65 +       while (cur < end) {
  66 +               while ((cur < end) && (*cur == ' ')) cur++;
  67 +               value = simple_strtol(cur, &next, 0);
  68 +               if (value == 0)
  69 +                       break;
  70 +               if (cur == next)
  71 +                       return -EINVAL;
  72 +
  73 +               cur = next;
  74 +
  75 +               if (value > (sbi->s_blocks_per_group - 1 - 1 - sbi->s_itb_per_group))
  76 +                       return -EINVAL;
  77 +
  78 +               /* they should add values in order */
  79 +               if (value <= prev)
  80 +                       return -EINVAL;
  81 +
  82 +               if (update)
  83 +                       sbi->s_mb_prealloc_table[num] = value;
  84 +
  85 +               prev = value;
  86 +               num++;
  87 +       }
  88 +
  89 +       if (num > EXT4_MAX_PREALLOC_TABLE - 1)
  90 +               return -EOVERFLOW;
  91 +
  92 +       if (update)
  93 +               sbi->s_mb_prealloc_table[num] = 0;
  94 +
  95 +       return 0;
  96 +}
  97 +
  98 +static ssize_t ext4_mb_prealloc_table_proc_write(struct file *file,
  99 +                                            const char __user *buf,
 100 +                                            size_t cnt, loff_t *pos)
 101 +{
 102 +       struct ext4_sb_info *sbi = EXT4_SB(PDE_DATA(file_inode(file)));
 103 +       char str[128];
 104 +       int rc;
 105 +
 106 +       if (cnt >= sizeof(str))
 107 +               return -EINVAL;
 108 +       if (copy_from_user(str, buf, cnt))
 109 +               return -EFAULT;
 110 +
 111 +       rc = ext4_mb_check_and_update_prealloc(sbi, str, cnt, 0);
 112 +       if (rc)
 113 +               return rc;
 114 +
 115 +       rc = ext4_mb_check_and_update_prealloc(sbi, str, cnt, 1);
 116 +       return rc ? rc : cnt;
 117 +}
 118 +
 119 +static int mb_prealloc_table_seq_show(struct seq_file *m, void *v)
 120 +{
 121 +       struct ext4_sb_info *sbi = EXT4_SB(m->private);
 122 +       int i;
 123 +
 124 +       for (i = 0; i < EXT4_MAX_PREALLOC_TABLE &&
 125 +                       sbi->s_mb_prealloc_table[i] != 0; i++)
 126 +               seq_printf(m, "%ld ", sbi->s_mb_prealloc_table[i]);
 127 +       seq_printf(m, "\n");
 128 +
 129 +       return 0;
 130 +}
 131 +
 132 +static int mb_prealloc_table_seq_open(struct inode *inode, struct file *file)
 133 +{
 134 +       return single_open(file, mb_prealloc_table_seq_show, PDE_DATA(inode));
 135 +}
 136 +
 137 +static const struct file_operations ext4_mb_prealloc_seq_fops = {
 138 +       .owner   = THIS_MODULE,
 139 +       .open    = mb_prealloc_table_seq_open,
 140 +       .read    = seq_read,
 141 +       .llseek  = seq_lseek,
 142 +       .release = single_release,
 143 +       .write   = ext4_mb_prealloc_table_proc_write,
 144 +};
 145 +
 146  static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
 147  {
 148         struct super_block *sb = PDE_DATA(inode);
 149 @@ -2552,7 +2648,7 @@ static int ext4_groupinfo_create_slab(si
 150  int ext4_mb_init(struct super_block *sb)
 151  {
 152         struct ext4_sb_info *sbi = EXT4_SB(sb);
 153 -       unsigned i, j;
 154 +       unsigned i, j, k, l;
 155         unsigned offset, offset_incr;
 156         unsigned max;
 157         int ret;
 158 @@ -2599,7 +2695,6 @@ int ext4_mb_init(struct super_block *sb)
 159         sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
 160         sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
 161         sbi->s_mb_stats = MB_DEFAULT_STATS;
 162 -       sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
 163         sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
 164         /*
 165          * The default group preallocation is 512, which for 4k block
 166 @@ -2623,9 +2718,29 @@ int ext4_mb_init(struct super_block *sb)
 167          * RAID stripe size so that preallocations don't fragment
 168          * the stripes.
 169          */
 170 -       if (sbi->s_stripe > 1) {
 171 -               sbi->s_mb_group_prealloc = roundup(
 172 -                       sbi->s_mb_group_prealloc, sbi->s_stripe);
 173 +
 174 +       /* Allocate table once */
 175 +       sbi->s_mb_prealloc_table = kzalloc(
 176 +               EXT4_MAX_PREALLOC_TABLE * sizeof(unsigned long), GFP_NOFS);
 177 +       if (sbi->s_mb_prealloc_table == NULL) {
 178 +               ret = -ENOMEM;
 179 +               goto out;
 180 +       }
 181 +
 182 +       if (sbi->s_stripe == 0) {
 183 +               for (k = 0, l = 4; k <= 9; ++k, l *= 2)
 184 +                       sbi->s_mb_prealloc_table[k] = l;
 185 +
 186 +               sbi->s_mb_small_req = 256;
 187 +               sbi->s_mb_large_req = 1024;
 188 +               sbi->s_mb_group_prealloc = 512;
 189 +       } else {
 190 +               for (k = 0, l = sbi->s_stripe; k <= 2; ++k, l *= 2)
 191 +                       sbi->s_mb_prealloc_table[k] = l;
 192 +
 193 +               sbi->s_mb_small_req = sbi->s_stripe;
 194 +               sbi->s_mb_large_req = sbi->s_stripe * 8;
 195 +               sbi->s_mb_group_prealloc = sbi->s_stripe * 4;
 196         }
 197
 198         sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
 199 @@ -2647,9 +2762,13 @@ int ext4_mb_init(struct super_block *sb)
 200         if (ret != 0)
 201                 goto out_free_locality_groups;
 202
 203 -       if (sbi->s_proc)
 204 +       if (sbi->s_proc) {
 205                 proc_create_data("mb_groups", S_IRUGO, sbi->s_proc,
 206                                  &ext4_mb_seq_groups_fops, sb);
 207 +               proc_create_data(EXT4_MB_PREALLOC_TABLE, S_IFREG | S_IRUGO |
 208 +                                S_IWUSR, sbi->s_proc,
 209 +                                &ext4_mb_prealloc_seq_fops, sb);
 210 +       }
 211
 212         return 0;
 213
 214 @@ -2657,6 +2776,7 @@ out_free_locality_groups:
 215         free_percpu(sbi->s_locality_groups);
 216         sbi->s_locality_groups = NULL;
 217  out:
 218 +       kfree(sbi->s_mb_prealloc_table);
 219         kfree(sbi->s_mb_offsets);
 220         sbi->s_mb_offsets = NULL;
 221         kfree(sbi->s_mb_maxs);
 222 @@ -2691,8 +2811,10 @@ int ext4_mb_release(struct super_block *
 223         struct ext4_sb_info *sbi = EXT4_SB(sb);
 224         struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
 225
 226 -       if (sbi->s_proc)
 227 +       if (sbi->s_proc) {
 228                 remove_proc_entry("mb_groups", sbi->s_proc);
 229 +               remove_proc_entry(EXT4_MB_PREALLOC_TABLE, sbi->s_proc);
 230 +       }
 231
 232         if (sbi->s_group_info) {
 233                 for (i = 0; i < ngroups; i++) {
 234 @@ -2700,6 +2740,7 @@ int ext4_mb_release(struct super_block *sb)
 235                 kvfree(group_info);
 236                 rcu_read_unlock();
 237         }
 238 +       kfree(sbi->s_mb_prealloc_table);
 239         kfree(sbi->s_mb_offsets);
 240         kfree(sbi->s_mb_maxs);
 241         iput(sbi->s_buddy_cache);
 242 @@ -2877,7 +2999,6 @@ ext4_mb_mark_diskspace_used(struct ext4_
 243         int err, len;
 244
 245         BUG_ON(ac->ac_status != AC_STATUS_FOUND);
 246 -       BUG_ON(ac->ac_b_ex.fe_len <= 0);
 247
 248         sb = ac->ac_sb;
 249         sbi = EXT4_SB(sb);
 250 @@ -3004,13 +3125,14 @@ ext4_mb_normalize_request(struct ext4_al
 251                                 struct ext4_allocation_request *ar)
 252  {
 253         struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
 254 -       int bsbits, max;
 255 +       int bsbits, i, wind;
 256         ext4_lblk_t end;
 257 -       loff_t size, start_off;
 258 +       loff_t size;
 259         loff_t orig_size __maybe_unused;
 260         ext4_lblk_t start;
 261         struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
 262         struct ext4_prealloc_space *pa;
 263 +       unsigned long value, last_non_zero;
 264
 265         /* do normalize only data requests, metadata requests
 266            do not need preallocation */
 267 @@ -3039,51 +3161,46 @@ ext4_mb_normalize_request(struct ext4_al
 268         size = size << bsbits;
 269         if (size < i_size_read(ac->ac_inode))
 270                 size = i_size_read(ac->ac_inode);
 271 -       orig_size = size;
 272 +       size = (size + ac->ac_sb->s_blocksize - 1) >> bsbits;
 273
 274 -       /* max size of free chunks */
 275 -       max = 2 << bsbits;
 276 +       start = wind = 0;
 277 +       value = last_non_zero = 0;
 278
 279 -#define NRL_CHECK_SIZE(req, size, max, chunk_size)     \
 280 -               (req <= (size) || max <= (chunk_size))
 281 +       /* let's choose preallocation window depending on file size */
 282 +       for (i = 0; i < EXT4_MAX_PREALLOC_TABLE; i++) {
 283 +               value = sbi->s_mb_prealloc_table[i];
 284 +               if (value == 0)
 285 +                       break;
 286 +               else
 287 +                       last_non_zero = value;
 288
 289 -       /* first, try to predict filesize */
 290 -       /* XXX: should this table be tunable? */
 291 -       start_off = 0;
 292 -       if (size <= 16 * 1024) {
 293 -               size = 16 * 1024;
 294 -       } else if (size <= 32 * 1024) {
 295 -               size = 32 * 1024;
 296 -       } else if (size <= 64 * 1024) {
 297 -               size = 64 * 1024;
 298 -       } else if (size <= 128 * 1024) {
 299 -               size = 128 * 1024;
 300 -       } else if (size <= 256 * 1024) {
 301 -               size = 256 * 1024;
 302 -       } else if (size <= 512 * 1024) {
 303 -               size = 512 * 1024;
 304 -       } else if (size <= 1024 * 1024) {
 305 -               size = 1024 * 1024;
 306 -       } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
 307 -               start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
 308 -                                               (21 - bsbits)) << 21;
 309 -               size = 2 * 1024 * 1024;
 310 -       } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
 311 -               start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
 312 -                                                       (22 - bsbits)) << 22;
 313 -               size = 4 * 1024 * 1024;
 314 -       } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
 315 -                                       (8<<20)>>bsbits, max, 8 * 1024)) {
 316 -               start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
 317 -                                                       (23 - bsbits)) << 23;
 318 -               size = 8 * 1024 * 1024;
 319 +               if (size <= value) {
 320 +                       wind = value;
 321 +                       break;
 322 +               }
 323 +       }
 324 +
 325 +       if (wind == 0) {
 326 +               if (last_non_zero != 0) {
 327 +                       __u64 tstart, tend;
 328 +                       /* file is quite large, we now preallocate with
 329 +                       * the biggest configured window with regart to
 330 +                       * logical offset */
 331 +                       wind = last_non_zero;
 332 +                       tstart = ac->ac_o_ex.fe_logical;
 333 +                       do_div(tstart, wind);
 334 +                       start = tstart * wind;
 335 +                       tend = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len - 1;
 336 +                       do_div(tend, wind);
 337 +                       tend = tend * wind + wind;
 338 +                       size = tend - start;
 339 +               }
 340         } else {
 341 -               start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
 342 -               size      = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
 343 -                                             ac->ac_o_ex.fe_len) << bsbits;
 344 +               size = wind;
 345         }
 346 -       size = size >> bsbits;
 347 -       start = start_off >> bsbits;
 348 +
 349 +
 350 +       orig_size = size;
 351
 352         /* don't cover already allocated blocks in selected range */
 353         if (ar->pleft && start <= ar->lleft) {
 354 @@ -3165,7 +3282,6 @@ ext4_mb_normalize_request(struct ext4_al
 355                          (unsigned long) ac->ac_o_ex.fe_logical);
 356                 BUG();
 357         }
 358 -       BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
 359
 360         /* now prepare goal request */
 361
 362 @@ -4130,11 +4246,19 @@ static void ext4_mb_group_or_file(struct
 363
 364         /* don't use group allocation for large files */
 365         size = max(size, isize);
 366 -       if (size > sbi->s_mb_stream_request) {
 367 +       if ((ac->ac_o_ex.fe_len >= sbi->s_mb_small_req) ||
 368 +           (size >= sbi->s_mb_large_req)) {
 369                 ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
 370                 return;
 371         }
 372
 373 +       /*
 374 +        * request is so large that we don't care about
 375 +        * streaming - it overweights any possible seek
 376 +        */
 377 +       if (ac->ac_o_ex.fe_len >= sbi->s_mb_large_req)
 378 +               return;
 379 +
 380         BUG_ON(ac->ac_lg != NULL);
 381         /*
 382          * locality group prealloc space are per cpu. The reason for having
 383 Index: linux-stage/fs/ext4/super.c
 384 ===================================================================
 385 --- linux-stage.orig/fs/ext4/super.c
 386 +++ linux-stage/fs/ext4/super.c
 387 @@ -2708,7 +2708,8 @@ EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats
 388  EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
 389  EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
 390  EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
 391 -EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
 392 +EXT4_RW_ATTR_SBI_UI(mb_small_req, s_mb_small_req);
 393 +EXT4_RW_ATTR_SBI_UI(mb_large_req, s_mb_large_req);
 394  EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
 395  EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
 396  EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
 397 @@ -2734,7 +2735,8 @@ static struct attribute *ext4_attrs[] =
 398         ATTR_LIST(mb_max_to_scan),
 399         ATTR_LIST(mb_min_to_scan),
 400         ATTR_LIST(mb_order2_req),
 401 -       ATTR_LIST(mb_stream_req),
 402 +       ATTR_LIST(mb_small_req),
 403 +       ATTR_LIST(mb_large_req),
 404         ATTR_LIST(mb_group_prealloc),
 405         ATTR_LIST(max_writeback_mb_bump),
 406         ATTR_LIST(extent_max_zeroout_kb),
 407 Index: linux-stage/fs/ext4/inode.c
 408 ===================================================================
 409 --- linux-stage.orig/fs/ext4/inode.c
 410 +++ linux-stage/fs/ext4/inode.c
 411 @@ -2457,6 +2457,9 @@ static int ext4_writepages(struct addres
 412                 ext4_journal_stop(handle);
 413         }
 414
 415 +       if (wbc->nr_to_write < sbi->s_mb_small_req)
 416 +               wbc->nr_to_write = sbi->s_mb_small_req;
 417 +
 418         if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 419                 range_whole = 1;
 420