fs/nilfs2/direct.c

   1 /*
   2  * direct.c - NILFS direct block pointer.
   3  *
   4  * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Koji Sato <koji@osrg.net>.
  21  */
  22
  23 #include <linux/errno.h>
  24 #include "nilfs.h"
  25 #include "page.h"
  26 #include "direct.h"
  27 #include "alloc.h"
  28
  29 static inline __le64 *nilfs_direct_dptrs(const struct nilfs_direct *direct)
  30 {
  31         return (__le64 *)
  32                 ((struct nilfs_direct_node *)direct->d_bmap.b_u.u_data + 1);
  33 }
  34
  35 static inline __u64
  36 nilfs_direct_get_ptr(const struct nilfs_direct *direct, __u64 key)
  37 {
  38         return nilfs_bmap_dptr_to_ptr(*(nilfs_direct_dptrs(direct) + key));
  39 }
  40
  41 static inline void nilfs_direct_set_ptr(struct nilfs_direct *direct,
  42                                         __u64 key, __u64 ptr)
  43 {
  44         *(nilfs_direct_dptrs(direct) + key) = nilfs_bmap_ptr_to_dptr(ptr);
  45 }
  46
  47 static int nilfs_direct_lookup(const struct nilfs_bmap *bmap,
  48                                __u64 key, int level, __u64 *ptrp)
  49 {
  50         struct nilfs_direct *direct;
  51         __u64 ptr;
  52
  53         direct = (struct nilfs_direct *)bmap;
  54         if ((key > NILFS_DIRECT_KEY_MAX) ||
  55             (level != 1) ||     /* XXX: use macro for level 1 */
  56             ((ptr = nilfs_direct_get_ptr(direct, key)) ==
  57              NILFS_BMAP_INVALID_PTR))
  58                 return -ENOENT;
  59
  60         if (ptrp != NULL)
  61                 *ptrp = ptr;
  62         return 0;
  63 }
  64
  65 static __u64
  66 nilfs_direct_find_target_v(const struct nilfs_direct *direct, __u64 key)
  67 {
  68         __u64 ptr;
  69
  70         ptr = nilfs_bmap_find_target_seq(&direct->d_bmap, key);
  71         if (ptr != NILFS_BMAP_INVALID_PTR)
  72                 /* sequential access */
  73                 return ptr;
  74         else
  75                 /* block group */
  76                 return nilfs_bmap_find_target_in_group(&direct->d_bmap);
  77 }
  78
  79 static void nilfs_direct_set_target_v(struct nilfs_direct *direct,
  80                                       __u64 key, __u64 ptr)
  81 {
  82         direct->d_bmap.b_last_allocated_key = key;
  83         direct->d_bmap.b_last_allocated_ptr = ptr;
  84 }
  85
  86 static int nilfs_direct_prepare_insert(struct nilfs_direct *direct,
  87                                        __u64 key,
  88                                        union nilfs_bmap_ptr_req *req,
  89                                        struct nilfs_bmap_stats *stats)
  90 {
  91         int ret;
  92
  93         if (direct->d_ops->dop_find_target != NULL)
  94                 req->bpr_ptr = direct->d_ops->dop_find_target(direct, key);
  95         ret = direct->d_bmap.b_pops->bpop_prepare_alloc_ptr(&direct->d_bmap,
  96                                                                req);
  97         if (ret < 0)
  98                 return ret;
  99
 100         stats->bs_nblocks = 1;
 101         return 0;
 102 }
 103
 104 static void nilfs_direct_commit_insert(struct nilfs_direct *direct,
 105                                        union nilfs_bmap_ptr_req *req,
 106                                        __u64 key, __u64 ptr)
 107 {
 108         struct buffer_head *bh;
 109
 110         /* ptr must be a pointer to a buffer head. */
 111         bh = (struct buffer_head *)((unsigned long)ptr);
 112         set_buffer_nilfs_volatile(bh);
 113
 114         if (direct->d_bmap.b_pops->bpop_commit_alloc_ptr != NULL)
 115                 direct->d_bmap.b_pops->bpop_commit_alloc_ptr(
 116                         &direct->d_bmap, req);
 117         nilfs_direct_set_ptr(direct, key, req->bpr_ptr);
 118
 119         if (!nilfs_bmap_dirty(&direct->d_bmap))
 120                 nilfs_bmap_set_dirty(&direct->d_bmap);
 121
 122         if (direct->d_ops->dop_set_target != NULL)
 123                 direct->d_ops->dop_set_target(direct, key, req->bpr_ptr);
 124 }
 125
 126 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 127 {
 128         struct nilfs_direct *direct;
 129         union nilfs_bmap_ptr_req req;
 130         struct nilfs_bmap_stats stats;
 131         int ret;
 132
 133         direct = (struct nilfs_direct *)bmap;
 134         if (key > NILFS_DIRECT_KEY_MAX)
 135                 return -ENOENT;
 136         if (nilfs_direct_get_ptr(direct, key) != NILFS_BMAP_INVALID_PTR)
 137                 return -EEXIST;
 138
 139         ret = nilfs_direct_prepare_insert(direct, key, &req, &stats);
 140         if (ret < 0)
 141                 return ret;
 142         nilfs_direct_commit_insert(direct, &req, key, ptr);
 143         nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
 144
 145         return 0;
 146 }
 147
 148 static int nilfs_direct_prepare_delete(struct nilfs_direct *direct,
 149                                        union nilfs_bmap_ptr_req *req,
 150                                        __u64 key,
 151                                        struct nilfs_bmap_stats *stats)
 152 {
 153         int ret;
 154
 155         if (direct->d_bmap.b_pops->bpop_prepare_end_ptr != NULL) {
 156                 req->bpr_ptr = nilfs_direct_get_ptr(direct, key);
 157                 ret = direct->d_bmap.b_pops->bpop_prepare_end_ptr(
 158                         &direct->d_bmap, req);
 159                 if (ret < 0)
 160                         return ret;
 161         }
 162
 163         stats->bs_nblocks = 1;
 164         return 0;
 165 }
 166
 167 static void nilfs_direct_commit_delete(struct nilfs_direct *direct,
 168                                        union nilfs_bmap_ptr_req *req,
 169                                        __u64 key)
 170 {
 171         if (direct->d_bmap.b_pops->bpop_commit_end_ptr != NULL)
 172                 direct->d_bmap.b_pops->bpop_commit_end_ptr(
 173                         &direct->d_bmap, req);
 174         nilfs_direct_set_ptr(direct, key, NILFS_BMAP_INVALID_PTR);
 175 }
 176
 177 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 178 {
 179         struct nilfs_direct *direct;
 180         union nilfs_bmap_ptr_req req;
 181         struct nilfs_bmap_stats stats;
 182         int ret;
 183
 184         direct = (struct nilfs_direct *)bmap;
 185         if ((key > NILFS_DIRECT_KEY_MAX) ||
 186             nilfs_direct_get_ptr(direct, key) == NILFS_BMAP_INVALID_PTR)
 187                 return -ENOENT;
 188
 189         ret = nilfs_direct_prepare_delete(direct, &req, key, &stats);
 190         if (ret < 0)
 191                 return ret;
 192         nilfs_direct_commit_delete(direct, &req, key);
 193         nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
 194
 195         return 0;
 196 }
 197
 198 static int nilfs_direct_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
 199 {
 200         struct nilfs_direct *direct;
 201         __u64 key, lastkey;
 202
 203         direct = (struct nilfs_direct *)bmap;
 204         lastkey = NILFS_DIRECT_KEY_MAX + 1;
 205         for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
 206                 if (nilfs_direct_get_ptr(direct, key) !=
 207                     NILFS_BMAP_INVALID_PTR)
 208                         lastkey = key;
 209
 210         if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
 211                 return -ENOENT;
 212
 213         BUG_ON(keyp == NULL);
 214         *keyp = lastkey;
 215
 216         return 0;
 217 }
 218
 219 static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
 220 {
 221         return key > NILFS_DIRECT_KEY_MAX;
 222 }
 223
 224 static int nilfs_direct_gather_data(struct nilfs_bmap *bmap,
 225                                     __u64 *keys, __u64 *ptrs, int nitems)
 226 {
 227         struct nilfs_direct *direct;
 228         __u64 key;
 229         __u64 ptr;
 230         int n;
 231
 232         direct = (struct nilfs_direct *)bmap;
 233         if (nitems > NILFS_DIRECT_NBLOCKS)
 234                 nitems = NILFS_DIRECT_NBLOCKS;
 235         n = 0;
 236         for (key = 0; key < nitems; key++) {
 237                 ptr = nilfs_direct_get_ptr(direct, key);
 238                 if (ptr != NILFS_BMAP_INVALID_PTR) {
 239                         keys[n] = key;
 240                         ptrs[n] = ptr;
 241                         n++;
 242                 }
 243         }
 244         return n;
 245 }
 246
 247 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
 248                                     __u64 key, __u64 *keys, __u64 *ptrs,
 249                                     int n, __u64 low, __u64 high)
 250 {
 251         struct nilfs_direct *direct;
 252         __le64 *dptrs;
 253         int ret, i, j;
 254
 255         /* no need to allocate any resource for conversion */
 256
 257         /* delete */
 258         ret = bmap->b_ops->bop_delete(bmap, key);
 259         if (ret < 0)
 260                 return ret;
 261
 262         /* free resources */
 263         if (bmap->b_ops->bop_clear != NULL)
 264                 bmap->b_ops->bop_clear(bmap);
 265
 266         /* convert */
 267         direct = (struct nilfs_direct *)bmap;
 268         dptrs = nilfs_direct_dptrs(direct);
 269         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
 270                 if ((j < n) && (i == keys[j])) {
 271                         dptrs[i] = (i != key) ?
 272                                 nilfs_bmap_ptr_to_dptr(ptrs[j]) :
 273                                 NILFS_BMAP_INVALID_PTR;
 274                         j++;
 275                 } else
 276                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
 277         }
 278
 279         nilfs_direct_init(bmap, low, high);
 280
 281         return 0;
 282 }
 283
 284 static int nilfs_direct_propagate_v(struct nilfs_direct *direct,
 285                                     struct buffer_head *bh)
 286 {
 287         union nilfs_bmap_ptr_req oldreq, newreq;
 288         __u64 key;
 289         __u64 ptr;
 290         int ret;
 291
 292         key = nilfs_bmap_data_get_key(&direct->d_bmap, bh);
 293         ptr = nilfs_direct_get_ptr(direct, key);
 294         if (!buffer_nilfs_volatile(bh)) {
 295                 oldreq.bpr_ptr = ptr;
 296                 newreq.bpr_ptr = ptr;
 297                 ret = nilfs_bmap_prepare_update(&direct->d_bmap, &oldreq,
 298                                                 &newreq);
 299                 if (ret < 0)
 300                         return ret;
 301                 nilfs_bmap_commit_update(&direct->d_bmap, &oldreq, &newreq);
 302                 set_buffer_nilfs_volatile(bh);
 303                 nilfs_direct_set_ptr(direct, key, newreq.bpr_ptr);
 304         } else
 305                 ret = nilfs_bmap_mark_dirty(&direct->d_bmap, ptr);
 306
 307         return ret;
 308 }
 309
 310 static int nilfs_direct_propagate(const struct nilfs_bmap *bmap,
 311                                   struct buffer_head *bh)
 312 {
 313         struct nilfs_direct *direct;
 314
 315         direct = (struct nilfs_direct *)bmap;
 316         return (direct->d_ops->dop_propagate != NULL) ?
 317                 direct->d_ops->dop_propagate(direct, bh) :
 318                 0;
 319 }
 320
 321 static int nilfs_direct_assign_v(struct nilfs_direct *direct,
 322                                  __u64 key, __u64 ptr,
 323                                  struct buffer_head **bh,
 324                                  sector_t blocknr,
 325                                  union nilfs_binfo *binfo)
 326 {
 327         union nilfs_bmap_ptr_req req;
 328         int ret;
 329
 330         req.bpr_ptr = ptr;
 331         ret = direct->d_bmap.b_pops->bpop_prepare_start_ptr(
 332                 &direct->d_bmap, &req);
 333         if (ret < 0)
 334                 return ret;
 335         direct->d_bmap.b_pops->bpop_commit_start_ptr(&direct->d_bmap,
 336                                                      &req, blocknr);
 337
 338         binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
 339         binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 340
 341         return 0;
 342 }
 343
 344 static int nilfs_direct_assign_p(struct nilfs_direct *direct,
 345                                  __u64 key, __u64 ptr,
 346                                  struct buffer_head **bh,
 347                                  sector_t blocknr,
 348                                  union nilfs_binfo *binfo)
 349 {
 350         nilfs_direct_set_ptr(direct, key, blocknr);
 351
 352         binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 353         binfo->bi_dat.bi_level = 0;
 354
 355         return 0;
 356 }
 357
 358 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
 359                                struct buffer_head **bh,
 360                                sector_t blocknr,
 361                                union nilfs_binfo *binfo)
 362 {
 363         struct nilfs_direct *direct;
 364         __u64 key;
 365         __u64 ptr;
 366
 367         direct = (struct nilfs_direct *)bmap;
 368         key = nilfs_bmap_data_get_key(bmap, *bh);
 369         BUG_ON(key > NILFS_DIRECT_KEY_MAX);
 370         ptr = nilfs_direct_get_ptr(direct, key);
 371         BUG_ON(ptr == NILFS_BMAP_INVALID_PTR);
 372
 373         return direct->d_ops->dop_assign(direct, key, ptr, bh,
 374                                          blocknr, binfo);
 375 }
 376
 377 static const struct nilfs_bmap_operations nilfs_direct_ops = {
 378         .bop_lookup             =       nilfs_direct_lookup,
 379         .bop_insert             =       nilfs_direct_insert,
 380         .bop_delete             =       nilfs_direct_delete,
 381         .bop_clear              =       NULL,
 382
 383         .bop_propagate          =       nilfs_direct_propagate,
 384
 385         .bop_lookup_dirty_buffers       =       NULL,
 386
 387         .bop_assign             =       nilfs_direct_assign,
 388         .bop_mark               =       NULL,
 389
 390         .bop_last_key           =       nilfs_direct_last_key,
 391         .bop_check_insert       =       nilfs_direct_check_insert,
 392         .bop_check_delete       =       NULL,
 393         .bop_gather_data        =       nilfs_direct_gather_data,
 394 };
 395
 396
 397 static const struct nilfs_direct_operations nilfs_direct_ops_v = {
 398         .dop_find_target        =       nilfs_direct_find_target_v,
 399         .dop_set_target         =       nilfs_direct_set_target_v,
 400         .dop_propagate          =       nilfs_direct_propagate_v,
 401         .dop_assign             =       nilfs_direct_assign_v,
 402 };
 403
 404 static const struct nilfs_direct_operations nilfs_direct_ops_p = {
 405         .dop_find_target        =       NULL,
 406         .dop_set_target         =       NULL,
 407         .dop_propagate          =       NULL,
 408         .dop_assign             =       nilfs_direct_assign_p,
 409 };
 410
 411 int nilfs_direct_init(struct nilfs_bmap *bmap, __u64 low, __u64 high)
 412 {
 413         struct nilfs_direct *direct;
 414
 415         direct = (struct nilfs_direct *)bmap;
 416         bmap->b_ops = &nilfs_direct_ops;
 417         bmap->b_low = low;
 418         bmap->b_high = high;
 419         switch (bmap->b_inode->i_ino) {
 420         case NILFS_DAT_INO:
 421                 direct->d_ops = &nilfs_direct_ops_p;
 422                 break;
 423         default:
 424                 direct->d_ops = &nilfs_direct_ops_v;
 425                 break;
 426         }
 427
 428         return 0;
 429 }