git.oblomov.eu Git - 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 #include "dat.h"
  29
  30 static inline __le64 *nilfs_direct_dptrs(const struct nilfs_direct *direct)
  31 {
  32         return (__le64 *)
  33                 ((struct nilfs_direct_node *)direct->d_bmap.b_u.u_data + 1);
  34 }
  35
  36 static inline __u64
  37 nilfs_direct_get_ptr(const struct nilfs_direct *direct, __u64 key)
  38 {
  39         return nilfs_bmap_dptr_to_ptr(*(nilfs_direct_dptrs(direct) + key));
  40 }
  41
  42 static inline void nilfs_direct_set_ptr(struct nilfs_direct *direct,
  43                                         __u64 key, __u64 ptr)
  44 {
  45         *(nilfs_direct_dptrs(direct) + key) = nilfs_bmap_ptr_to_dptr(ptr);
  46 }
  47
  48 static int nilfs_direct_lookup(const struct nilfs_bmap *bmap,
  49                                __u64 key, int level, __u64 *ptrp)
  50 {
  51         struct nilfs_direct *direct;
  52         __u64 ptr;
  53
  54         direct = (struct nilfs_direct *)bmap;
  55         if ((key > NILFS_DIRECT_KEY_MAX) ||
  56             (level != 1) ||     /* XXX: use macro for level 1 */
  57             ((ptr = nilfs_direct_get_ptr(direct, key)) ==
  58              NILFS_BMAP_INVALID_PTR))
  59                 return -ENOENT;
  60
  61         if (ptrp != NULL)
  62                 *ptrp = ptr;
  63         return 0;
  64 }
  65
  66 static int nilfs_direct_lookup_contig(const struct nilfs_bmap *bmap,
  67                                       __u64 key, __u64 *ptrp,
  68                                       unsigned maxblocks)
  69 {
  70         struct nilfs_direct *direct = (struct nilfs_direct *)bmap;
  71         struct inode *dat = NULL;
  72         __u64 ptr, ptr2;
  73         sector_t blocknr;
  74         int ret, cnt;
  75
  76         if (key > NILFS_DIRECT_KEY_MAX ||
  77             (ptr = nilfs_direct_get_ptr(direct, key)) ==
  78             NILFS_BMAP_INVALID_PTR)
  79                 return -ENOENT;
  80
  81         if (NILFS_BMAP_USE_VBN(bmap)) {
  82                 dat = nilfs_bmap_get_dat(bmap);
  83                 ret = nilfs_dat_translate(dat, ptr, &blocknr);
  84                 if (ret < 0)
  85                         return ret;
  86                 ptr = blocknr;
  87         }
  88
  89         maxblocks = min_t(unsigned, maxblocks, NILFS_DIRECT_KEY_MAX - key + 1);
  90         for (cnt = 1; cnt < maxblocks &&
  91                      (ptr2 = nilfs_direct_get_ptr(direct, key + cnt)) !=
  92                      NILFS_BMAP_INVALID_PTR;
  93              cnt++) {
  94                 if (dat) {
  95                         ret = nilfs_dat_translate(dat, ptr2, &blocknr);
  96                         if (ret < 0)
  97                                 return ret;
  98                         ptr2 = blocknr;
  99                 }
 100                 if (ptr2 != ptr + cnt)
 101                         break;
 102         }
 103         *ptrp = ptr;
 104         return cnt;
 105 }
 106
 107 static __u64
 108 nilfs_direct_find_target_v(const struct nilfs_direct *direct, __u64 key)
 109 {
 110         __u64 ptr;
 111
 112         ptr = nilfs_bmap_find_target_seq(&direct->d_bmap, key);
 113         if (ptr != NILFS_BMAP_INVALID_PTR)
 114                 /* sequential access */
 115                 return ptr;
 116         else
 117                 /* block group */
 118                 return nilfs_bmap_find_target_in_group(&direct->d_bmap);
 119 }
 120
 121 static void nilfs_direct_set_target_v(struct nilfs_direct *direct,
 122                                       __u64 key, __u64 ptr)
 123 {
 124         direct->d_bmap.b_last_allocated_key = key;
 125         direct->d_bmap.b_last_allocated_ptr = ptr;
 126 }
 127
 128 static int nilfs_direct_prepare_insert(struct nilfs_direct *direct,
 129                                        __u64 key,
 130                                        union nilfs_bmap_ptr_req *req,
 131                                        struct nilfs_bmap_stats *stats)
 132 {
 133         int ret;
 134
 135         if (NILFS_BMAP_USE_VBN(&direct->d_bmap))
 136                 req->bpr_ptr = nilfs_direct_find_target_v(direct, key);
 137         ret = nilfs_bmap_prepare_alloc_ptr(&direct->d_bmap, req);
 138         if (ret < 0)
 139                 return ret;
 140
 141         stats->bs_nblocks = 1;
 142         return 0;
 143 }
 144
 145 static void nilfs_direct_commit_insert(struct nilfs_direct *direct,
 146                                        union nilfs_bmap_ptr_req *req,
 147                                        __u64 key, __u64 ptr)
 148 {
 149         struct buffer_head *bh;
 150
 151         /* ptr must be a pointer to a buffer head. */
 152         bh = (struct buffer_head *)((unsigned long)ptr);
 153         set_buffer_nilfs_volatile(bh);
 154
 155         nilfs_bmap_commit_alloc_ptr(&direct->d_bmap, req);
 156         nilfs_direct_set_ptr(direct, key, req->bpr_ptr);
 157
 158         if (!nilfs_bmap_dirty(&direct->d_bmap))
 159                 nilfs_bmap_set_dirty(&direct->d_bmap);
 160
 161         if (NILFS_BMAP_USE_VBN(&direct->d_bmap))
 162                 nilfs_direct_set_target_v(direct, key, req->bpr_ptr);
 163 }
 164
 165 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 166 {
 167         struct nilfs_direct *direct;
 168         union nilfs_bmap_ptr_req req;
 169         struct nilfs_bmap_stats stats;
 170         int ret;
 171
 172         direct = (struct nilfs_direct *)bmap;
 173         if (key > NILFS_DIRECT_KEY_MAX)
 174                 return -ENOENT;
 175         if (nilfs_direct_get_ptr(direct, key) != NILFS_BMAP_INVALID_PTR)
 176                 return -EEXIST;
 177
 178         ret = nilfs_direct_prepare_insert(direct, key, &req, &stats);
 179         if (ret < 0)
 180                 return ret;
 181         nilfs_direct_commit_insert(direct, &req, key, ptr);
 182         nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
 183
 184         return 0;
 185 }
 186
 187 static int nilfs_direct_prepare_delete(struct nilfs_direct *direct,
 188                                        union nilfs_bmap_ptr_req *req,
 189                                        __u64 key,
 190                                        struct nilfs_bmap_stats *stats)
 191 {
 192         int ret;
 193
 194         req->bpr_ptr = nilfs_direct_get_ptr(direct, key);
 195         ret = nilfs_bmap_prepare_end_ptr(&direct->d_bmap, req);
 196         if (!ret)
 197                 stats->bs_nblocks = 1;
 198         return ret;
 199 }
 200
 201 static void nilfs_direct_commit_delete(struct nilfs_direct *direct,
 202                                        union nilfs_bmap_ptr_req *req,
 203                                        __u64 key)
 204 {
 205         nilfs_bmap_commit_end_ptr(&direct->d_bmap, req);
 206         nilfs_direct_set_ptr(direct, key, NILFS_BMAP_INVALID_PTR);
 207 }
 208
 209 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 210 {
 211         struct nilfs_direct *direct;
 212         union nilfs_bmap_ptr_req req;
 213         struct nilfs_bmap_stats stats;
 214         int ret;
 215
 216         direct = (struct nilfs_direct *)bmap;
 217         if ((key > NILFS_DIRECT_KEY_MAX) ||
 218             nilfs_direct_get_ptr(direct, key) == NILFS_BMAP_INVALID_PTR)
 219                 return -ENOENT;
 220
 221         ret = nilfs_direct_prepare_delete(direct, &req, key, &stats);
 222         if (ret < 0)
 223                 return ret;
 224         nilfs_direct_commit_delete(direct, &req, key);
 225         nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
 226
 227         return 0;
 228 }
 229
 230 static int nilfs_direct_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
 231 {
 232         struct nilfs_direct *direct;
 233         __u64 key, lastkey;
 234
 235         direct = (struct nilfs_direct *)bmap;
 236         lastkey = NILFS_DIRECT_KEY_MAX + 1;
 237         for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
 238                 if (nilfs_direct_get_ptr(direct, key) !=
 239                     NILFS_BMAP_INVALID_PTR)
 240                         lastkey = key;
 241
 242         if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
 243                 return -ENOENT;
 244
 245         *keyp = lastkey;
 246
 247         return 0;
 248 }
 249
 250 static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
 251 {
 252         return key > NILFS_DIRECT_KEY_MAX;
 253 }
 254
 255 static int nilfs_direct_gather_data(struct nilfs_bmap *bmap,
 256                                     __u64 *keys, __u64 *ptrs, int nitems)
 257 {
 258         struct nilfs_direct *direct;
 259         __u64 key;
 260         __u64 ptr;
 261         int n;
 262
 263         direct = (struct nilfs_direct *)bmap;
 264         if (nitems > NILFS_DIRECT_NBLOCKS)
 265                 nitems = NILFS_DIRECT_NBLOCKS;
 266         n = 0;
 267         for (key = 0; key < nitems; key++) {
 268                 ptr = nilfs_direct_get_ptr(direct, key);
 269                 if (ptr != NILFS_BMAP_INVALID_PTR) {
 270                         keys[n] = key;
 271                         ptrs[n] = ptr;
 272                         n++;
 273                 }
 274         }
 275         return n;
 276 }
 277
 278 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
 279                                     __u64 key, __u64 *keys, __u64 *ptrs, int n)
 280 {
 281         struct nilfs_direct *direct;
 282         __le64 *dptrs;
 283         int ret, i, j;
 284
 285         /* no need to allocate any resource for conversion */
 286
 287         /* delete */
 288         ret = bmap->b_ops->bop_delete(bmap, key);
 289         if (ret < 0)
 290                 return ret;
 291
 292         /* free resources */
 293         if (bmap->b_ops->bop_clear != NULL)
 294                 bmap->b_ops->bop_clear(bmap);
 295
 296         /* convert */
 297         direct = (struct nilfs_direct *)bmap;
 298         dptrs = nilfs_direct_dptrs(direct);
 299         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
 300                 if ((j < n) && (i == keys[j])) {
 301                         dptrs[i] = (i != key) ?
 302                                 nilfs_bmap_ptr_to_dptr(ptrs[j]) :
 303                                 NILFS_BMAP_INVALID_PTR;
 304                         j++;
 305                 } else
 306                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
 307         }
 308
 309         nilfs_direct_init(bmap);
 310         return 0;
 311 }
 312
 313 static int nilfs_direct_propagate_v(struct nilfs_direct *direct,
 314                                     struct buffer_head *bh)
 315 {
 316         union nilfs_bmap_ptr_req oldreq, newreq;
 317         __u64 key;
 318         __u64 ptr;
 319         int ret;
 320
 321         key = nilfs_bmap_data_get_key(&direct->d_bmap, bh);
 322         ptr = nilfs_direct_get_ptr(direct, key);
 323         if (!buffer_nilfs_volatile(bh)) {
 324                 oldreq.bpr_ptr = ptr;
 325                 newreq.bpr_ptr = ptr;
 326                 ret = nilfs_bmap_prepare_update_v(&direct->d_bmap, &oldreq,
 327                                                   &newreq);
 328                 if (ret < 0)
 329                         return ret;
 330                 nilfs_bmap_commit_update_v(&direct->d_bmap, &oldreq, &newreq);
 331                 set_buffer_nilfs_volatile(bh);
 332                 nilfs_direct_set_ptr(direct, key, newreq.bpr_ptr);
 333         } else
 334                 ret = nilfs_bmap_mark_dirty(&direct->d_bmap, ptr);
 335
 336         return ret;
 337 }
 338
 339 static int nilfs_direct_propagate(const struct nilfs_bmap *bmap,
 340                                   struct buffer_head *bh)
 341 {
 342         struct nilfs_direct *direct = (struct nilfs_direct *)bmap;
 343
 344         return NILFS_BMAP_USE_VBN(bmap) ?
 345                 nilfs_direct_propagate_v(direct, bh) : 0;
 346 }
 347
 348 static int nilfs_direct_assign_v(struct nilfs_direct *direct,
 349                                  __u64 key, __u64 ptr,
 350                                  struct buffer_head **bh,
 351                                  sector_t blocknr,
 352                                  union nilfs_binfo *binfo)
 353 {
 354         union nilfs_bmap_ptr_req req;
 355         int ret;
 356
 357         req.bpr_ptr = ptr;
 358         ret = nilfs_bmap_start_v(&direct->d_bmap, &req, blocknr);
 359         if (unlikely(ret < 0))
 360                 return ret;
 361
 362         binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
 363         binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 364
 365         return 0;
 366 }
 367
 368 static int nilfs_direct_assign_p(struct nilfs_direct *direct,
 369                                  __u64 key, __u64 ptr,
 370                                  struct buffer_head **bh,
 371                                  sector_t blocknr,
 372                                  union nilfs_binfo *binfo)
 373 {
 374         nilfs_direct_set_ptr(direct, key, blocknr);
 375
 376         binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 377         binfo->bi_dat.bi_level = 0;
 378
 379         return 0;
 380 }
 381
 382 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
 383                                struct buffer_head **bh,
 384                                sector_t blocknr,
 385                                union nilfs_binfo *binfo)
 386 {
 387         struct nilfs_direct *direct;
 388         __u64 key;
 389         __u64 ptr;
 390
 391         direct = (struct nilfs_direct *)bmap;
 392         key = nilfs_bmap_data_get_key(bmap, *bh);
 393         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
 394                 printk(KERN_CRIT "%s: invalid key: %llu\n", __func__,
 395                        (unsigned long long)key);
 396                 return -EINVAL;
 397         }
 398         ptr = nilfs_direct_get_ptr(direct, key);
 399         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
 400                 printk(KERN_CRIT "%s: invalid pointer: %llu\n", __func__,
 401                        (unsigned long long)ptr);
 402                 return -EINVAL;
 403         }
 404
 405         return NILFS_BMAP_USE_VBN(bmap) ?
 406                 nilfs_direct_assign_v(direct, key, ptr, bh, blocknr, binfo) :
 407                 nilfs_direct_assign_p(direct, key, ptr, bh, blocknr, binfo);
 408 }
 409
 410 static const struct nilfs_bmap_operations nilfs_direct_ops = {
 411         .bop_lookup             =       nilfs_direct_lookup,
 412         .bop_lookup_contig      =       nilfs_direct_lookup_contig,
 413         .bop_insert             =       nilfs_direct_insert,
 414         .bop_delete             =       nilfs_direct_delete,
 415         .bop_clear              =       NULL,
 416
 417         .bop_propagate          =       nilfs_direct_propagate,
 418
 419         .bop_lookup_dirty_buffers       =       NULL,
 420
 421         .bop_assign             =       nilfs_direct_assign,
 422         .bop_mark               =       NULL,
 423
 424         .bop_last_key           =       nilfs_direct_last_key,
 425         .bop_check_insert       =       nilfs_direct_check_insert,
 426         .bop_check_delete       =       NULL,
 427         .bop_gather_data        =       nilfs_direct_gather_data,
 428 };
 429
 430
 431 int nilfs_direct_init(struct nilfs_bmap *bmap)
 432 {
 433         bmap->b_ops = &nilfs_direct_ops;
 434         return 0;
 435 }