SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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         direct->d_bmap.b_pops->bpop_commit_alloc_ptr(&direct->d_bmap, req);
 115         nilfs_direct_set_ptr(direct, key, req->bpr_ptr);
 116
 117         if (!nilfs_bmap_dirty(&direct->d_bmap))
 118                 nilfs_bmap_set_dirty(&direct->d_bmap);
 119
 120         if (direct->d_ops->dop_set_target != NULL)
 121                 direct->d_ops->dop_set_target(direct, key, req->bpr_ptr);
 122 }
 123
 124 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 125 {
 126         struct nilfs_direct *direct;
 127         union nilfs_bmap_ptr_req req;
 128         struct nilfs_bmap_stats stats;
 129         int ret;
 130
 131         direct = (struct nilfs_direct *)bmap;
 132         if (key > NILFS_DIRECT_KEY_MAX)
 133                 return -ENOENT;
 134         if (nilfs_direct_get_ptr(direct, key) != NILFS_BMAP_INVALID_PTR)
 135                 return -EEXIST;
 136
 137         ret = nilfs_direct_prepare_insert(direct, key, &req, &stats);
 138         if (ret < 0)
 139                 return ret;
 140         nilfs_direct_commit_insert(direct, &req, key, ptr);
 141         nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
 142
 143         return 0;
 144 }
 145
 146 static int nilfs_direct_prepare_delete(struct nilfs_direct *direct,
 147                                        union nilfs_bmap_ptr_req *req,
 148                                        __u64 key,
 149                                        struct nilfs_bmap_stats *stats)
 150 {
 151         int ret;
 152
 153         if (direct->d_bmap.b_pops->bpop_prepare_end_ptr != NULL) {
 154                 req->bpr_ptr = nilfs_direct_get_ptr(direct, key);
 155                 ret = direct->d_bmap.b_pops->bpop_prepare_end_ptr(
 156                         &direct->d_bmap, req);
 157                 if (ret < 0)
 158                         return ret;
 159         }
 160
 161         stats->bs_nblocks = 1;
 162         return 0;
 163 }
 164
 165 static void nilfs_direct_commit_delete(struct nilfs_direct *direct,
 166                                        union nilfs_bmap_ptr_req *req,
 167                                        __u64 key)
 168 {
 169         if (direct->d_bmap.b_pops->bpop_commit_end_ptr != NULL)
 170                 direct->d_bmap.b_pops->bpop_commit_end_ptr(
 171                         &direct->d_bmap, req);
 172         nilfs_direct_set_ptr(direct, key, NILFS_BMAP_INVALID_PTR);
 173 }
 174
 175 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 176 {
 177         struct nilfs_direct *direct;
 178         union nilfs_bmap_ptr_req req;
 179         struct nilfs_bmap_stats stats;
 180         int ret;
 181
 182         direct = (struct nilfs_direct *)bmap;
 183         if ((key > NILFS_DIRECT_KEY_MAX) ||
 184             nilfs_direct_get_ptr(direct, key) == NILFS_BMAP_INVALID_PTR)
 185                 return -ENOENT;
 186
 187         ret = nilfs_direct_prepare_delete(direct, &req, key, &stats);
 188         if (ret < 0)
 189                 return ret;
 190         nilfs_direct_commit_delete(direct, &req, key);
 191         nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
 192
 193         return 0;
 194 }
 195
 196 static int nilfs_direct_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
 197 {
 198         struct nilfs_direct *direct;
 199         __u64 key, lastkey;
 200
 201         direct = (struct nilfs_direct *)bmap;
 202         lastkey = NILFS_DIRECT_KEY_MAX + 1;
 203         for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
 204                 if (nilfs_direct_get_ptr(direct, key) !=
 205                     NILFS_BMAP_INVALID_PTR)
 206                         lastkey = key;
 207
 208         if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
 209                 return -ENOENT;
 210
 211         *keyp = lastkey;
 212
 213         return 0;
 214 }
 215
 216 static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
 217 {
 218         return key > NILFS_DIRECT_KEY_MAX;
 219 }
 220
 221 static int nilfs_direct_gather_data(struct nilfs_bmap *bmap,
 222                                     __u64 *keys, __u64 *ptrs, int nitems)
 223 {
 224         struct nilfs_direct *direct;
 225         __u64 key;
 226         __u64 ptr;
 227         int n;
 228
 229         direct = (struct nilfs_direct *)bmap;
 230         if (nitems > NILFS_DIRECT_NBLOCKS)
 231                 nitems = NILFS_DIRECT_NBLOCKS;
 232         n = 0;
 233         for (key = 0; key < nitems; key++) {
 234                 ptr = nilfs_direct_get_ptr(direct, key);
 235                 if (ptr != NILFS_BMAP_INVALID_PTR) {
 236                         keys[n] = key;
 237                         ptrs[n] = ptr;
 238                         n++;
 239                 }
 240         }
 241         return n;
 242 }
 243
 244 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
 245                                     __u64 key, __u64 *keys, __u64 *ptrs, int n)
 246 {
 247         struct nilfs_direct *direct;
 248         __le64 *dptrs;
 249         int ret, i, j;
 250
 251         /* no need to allocate any resource for conversion */
 252
 253         /* delete */
 254         ret = bmap->b_ops->bop_delete(bmap, key);
 255         if (ret < 0)
 256                 return ret;
 257
 258         /* free resources */
 259         if (bmap->b_ops->bop_clear != NULL)
 260                 bmap->b_ops->bop_clear(bmap);
 261
 262         /* convert */
 263         direct = (struct nilfs_direct *)bmap;
 264         dptrs = nilfs_direct_dptrs(direct);
 265         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
 266                 if ((j < n) && (i == keys[j])) {
 267                         dptrs[i] = (i != key) ?
 268                                 nilfs_bmap_ptr_to_dptr(ptrs[j]) :
 269                                 NILFS_BMAP_INVALID_PTR;
 270                         j++;
 271                 } else
 272                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
 273         }
 274
 275         nilfs_direct_init(bmap);
 276         return 0;
 277 }
 278
 279 static int nilfs_direct_propagate_v(struct nilfs_direct *direct,
 280                                     struct buffer_head *bh)
 281 {
 282         union nilfs_bmap_ptr_req oldreq, newreq;
 283         __u64 key;
 284         __u64 ptr;
 285         int ret;
 286
 287         key = nilfs_bmap_data_get_key(&direct->d_bmap, bh);
 288         ptr = nilfs_direct_get_ptr(direct, key);
 289         if (!buffer_nilfs_volatile(bh)) {
 290                 oldreq.bpr_ptr = ptr;
 291                 newreq.bpr_ptr = ptr;
 292                 ret = nilfs_bmap_prepare_update(&direct->d_bmap, &oldreq,
 293                                                 &newreq);
 294                 if (ret < 0)
 295                         return ret;
 296                 nilfs_bmap_commit_update(&direct->d_bmap, &oldreq, &newreq);
 297                 set_buffer_nilfs_volatile(bh);
 298                 nilfs_direct_set_ptr(direct, key, newreq.bpr_ptr);
 299         } else
 300                 ret = nilfs_bmap_mark_dirty(&direct->d_bmap, ptr);
 301
 302         return ret;
 303 }
 304
 305 static int nilfs_direct_propagate(const struct nilfs_bmap *bmap,
 306                                   struct buffer_head *bh)
 307 {
 308         struct nilfs_direct *direct;
 309
 310         direct = (struct nilfs_direct *)bmap;
 311         return (direct->d_ops->dop_propagate != NULL) ?
 312                 direct->d_ops->dop_propagate(direct, bh) :
 313                 0;
 314 }
 315
 316 static int nilfs_direct_assign_v(struct nilfs_direct *direct,
 317                                  __u64 key, __u64 ptr,
 318                                  struct buffer_head **bh,
 319                                  sector_t blocknr,
 320                                  union nilfs_binfo *binfo)
 321 {
 322         union nilfs_bmap_ptr_req req;
 323         int ret;
 324
 325         req.bpr_ptr = ptr;
 326         ret = nilfs_bmap_start_v(&direct->d_bmap, &req, blocknr);
 327         if (unlikely(ret < 0))
 328                 return ret;
 329
 330         binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
 331         binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 332
 333         return 0;
 334 }
 335
 336 static int nilfs_direct_assign_p(struct nilfs_direct *direct,
 337                                  __u64 key, __u64 ptr,
 338                                  struct buffer_head **bh,
 339                                  sector_t blocknr,
 340                                  union nilfs_binfo *binfo)
 341 {
 342         nilfs_direct_set_ptr(direct, key, blocknr);
 343
 344         binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 345         binfo->bi_dat.bi_level = 0;
 346
 347         return 0;
 348 }
 349
 350 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
 351                                struct buffer_head **bh,
 352                                sector_t blocknr,
 353                                union nilfs_binfo *binfo)
 354 {
 355         struct nilfs_direct *direct;
 356         __u64 key;
 357         __u64 ptr;
 358
 359         direct = (struct nilfs_direct *)bmap;
 360         key = nilfs_bmap_data_get_key(bmap, *bh);
 361         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
 362                 printk(KERN_CRIT "%s: invalid key: %llu\n", __func__,
 363                        (unsigned long long)key);
 364                 return -EINVAL;
 365         }
 366         ptr = nilfs_direct_get_ptr(direct, key);
 367         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
 368                 printk(KERN_CRIT "%s: invalid pointer: %llu\n", __func__,
 369                        (unsigned long long)ptr);
 370                 return -EINVAL;
 371         }
 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)
 412 {
 413         struct nilfs_direct *direct = (struct nilfs_direct *)bmap;
 414
 415         bmap->b_ops = &nilfs_direct_ops;
 416         switch (bmap->b_inode->i_ino) {
 417         case NILFS_DAT_INO:
 418                 direct->d_ops = &nilfs_direct_ops_p;
 419                 break;
 420         default:
 421                 direct->d_ops = &nilfs_direct_ops_v;
 422                 break;
 423         }
 424
 425         return 0;
 426 }