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 (NILFS_BMAP_USE_VBN(&direct->d_bmap))
  94                 req->bpr_ptr = nilfs_direct_find_target_v(direct, key);
  95         ret = nilfs_bmap_prepare_alloc_ptr(&direct->d_bmap, req);
  96         if (ret < 0)
  97                 return ret;
  98
  99         stats->bs_nblocks = 1;
 100         return 0;
 101 }
 102
 103 static void nilfs_direct_commit_insert(struct nilfs_direct *direct,
 104                                        union nilfs_bmap_ptr_req *req,
 105                                        __u64 key, __u64 ptr)
 106 {
 107         struct buffer_head *bh;
 108
 109         /* ptr must be a pointer to a buffer head. */
 110         bh = (struct buffer_head *)((unsigned long)ptr);
 111         set_buffer_nilfs_volatile(bh);
 112
 113         nilfs_bmap_commit_alloc_ptr(&direct->d_bmap, req);
 114         nilfs_direct_set_ptr(direct, key, req->bpr_ptr);
 115
 116         if (!nilfs_bmap_dirty(&direct->d_bmap))
 117                 nilfs_bmap_set_dirty(&direct->d_bmap);
 118
 119         if (NILFS_BMAP_USE_VBN(&direct->d_bmap))
 120                 nilfs_direct_set_target_v(direct, key, req->bpr_ptr);
 121 }
 122
 123 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 124 {
 125         struct nilfs_direct *direct;
 126         union nilfs_bmap_ptr_req req;
 127         struct nilfs_bmap_stats stats;
 128         int ret;
 129
 130         direct = (struct nilfs_direct *)bmap;
 131         if (key > NILFS_DIRECT_KEY_MAX)
 132                 return -ENOENT;
 133         if (nilfs_direct_get_ptr(direct, key) != NILFS_BMAP_INVALID_PTR)
 134                 return -EEXIST;
 135
 136         ret = nilfs_direct_prepare_insert(direct, key, &req, &stats);
 137         if (ret < 0)
 138                 return ret;
 139         nilfs_direct_commit_insert(direct, &req, key, ptr);
 140         nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
 141
 142         return 0;
 143 }
 144
 145 static int nilfs_direct_prepare_delete(struct nilfs_direct *direct,
 146                                        union nilfs_bmap_ptr_req *req,
 147                                        __u64 key,
 148                                        struct nilfs_bmap_stats *stats)
 149 {
 150         int ret;
 151
 152         req->bpr_ptr = nilfs_direct_get_ptr(direct, key);
 153         ret = nilfs_bmap_prepare_end_ptr(&direct->d_bmap, req);
 154         if (!ret)
 155                 stats->bs_nblocks = 1;
 156         return ret;
 157 }
 158
 159 static void nilfs_direct_commit_delete(struct nilfs_direct *direct,
 160                                        union nilfs_bmap_ptr_req *req,
 161                                        __u64 key)
 162 {
 163         nilfs_bmap_commit_end_ptr(&direct->d_bmap, req);
 164         nilfs_direct_set_ptr(direct, key, NILFS_BMAP_INVALID_PTR);
 165 }
 166
 167 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 168 {
 169         struct nilfs_direct *direct;
 170         union nilfs_bmap_ptr_req req;
 171         struct nilfs_bmap_stats stats;
 172         int ret;
 173
 174         direct = (struct nilfs_direct *)bmap;
 175         if ((key > NILFS_DIRECT_KEY_MAX) ||
 176             nilfs_direct_get_ptr(direct, key) == NILFS_BMAP_INVALID_PTR)
 177                 return -ENOENT;
 178
 179         ret = nilfs_direct_prepare_delete(direct, &req, key, &stats);
 180         if (ret < 0)
 181                 return ret;
 182         nilfs_direct_commit_delete(direct, &req, key);
 183         nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
 184
 185         return 0;
 186 }
 187
 188 static int nilfs_direct_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
 189 {
 190         struct nilfs_direct *direct;
 191         __u64 key, lastkey;
 192
 193         direct = (struct nilfs_direct *)bmap;
 194         lastkey = NILFS_DIRECT_KEY_MAX + 1;
 195         for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
 196                 if (nilfs_direct_get_ptr(direct, key) !=
 197                     NILFS_BMAP_INVALID_PTR)
 198                         lastkey = key;
 199
 200         if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
 201                 return -ENOENT;
 202
 203         *keyp = lastkey;
 204
 205         return 0;
 206 }
 207
 208 static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
 209 {
 210         return key > NILFS_DIRECT_KEY_MAX;
 211 }
 212
 213 static int nilfs_direct_gather_data(struct nilfs_bmap *bmap,
 214                                     __u64 *keys, __u64 *ptrs, int nitems)
 215 {
 216         struct nilfs_direct *direct;
 217         __u64 key;
 218         __u64 ptr;
 219         int n;
 220
 221         direct = (struct nilfs_direct *)bmap;
 222         if (nitems > NILFS_DIRECT_NBLOCKS)
 223                 nitems = NILFS_DIRECT_NBLOCKS;
 224         n = 0;
 225         for (key = 0; key < nitems; key++) {
 226                 ptr = nilfs_direct_get_ptr(direct, key);
 227                 if (ptr != NILFS_BMAP_INVALID_PTR) {
 228                         keys[n] = key;
 229                         ptrs[n] = ptr;
 230                         n++;
 231                 }
 232         }
 233         return n;
 234 }
 235
 236 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
 237                                     __u64 key, __u64 *keys, __u64 *ptrs, int n)
 238 {
 239         struct nilfs_direct *direct;
 240         __le64 *dptrs;
 241         int ret, i, j;
 242
 243         /* no need to allocate any resource for conversion */
 244
 245         /* delete */
 246         ret = bmap->b_ops->bop_delete(bmap, key);
 247         if (ret < 0)
 248                 return ret;
 249
 250         /* free resources */
 251         if (bmap->b_ops->bop_clear != NULL)
 252                 bmap->b_ops->bop_clear(bmap);
 253
 254         /* convert */
 255         direct = (struct nilfs_direct *)bmap;
 256         dptrs = nilfs_direct_dptrs(direct);
 257         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
 258                 if ((j < n) && (i == keys[j])) {
 259                         dptrs[i] = (i != key) ?
 260                                 nilfs_bmap_ptr_to_dptr(ptrs[j]) :
 261                                 NILFS_BMAP_INVALID_PTR;
 262                         j++;
 263                 } else
 264                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
 265         }
 266
 267         nilfs_direct_init(bmap);
 268         return 0;
 269 }
 270
 271 static int nilfs_direct_propagate_v(struct nilfs_direct *direct,
 272                                     struct buffer_head *bh)
 273 {
 274         union nilfs_bmap_ptr_req oldreq, newreq;
 275         __u64 key;
 276         __u64 ptr;
 277         int ret;
 278
 279         key = nilfs_bmap_data_get_key(&direct->d_bmap, bh);
 280         ptr = nilfs_direct_get_ptr(direct, key);
 281         if (!buffer_nilfs_volatile(bh)) {
 282                 oldreq.bpr_ptr = ptr;
 283                 newreq.bpr_ptr = ptr;
 284                 ret = nilfs_bmap_prepare_update_v(&direct->d_bmap, &oldreq,
 285                                                   &newreq);
 286                 if (ret < 0)
 287                         return ret;
 288                 nilfs_bmap_commit_update_v(&direct->d_bmap, &oldreq, &newreq);
 289                 set_buffer_nilfs_volatile(bh);
 290                 nilfs_direct_set_ptr(direct, key, newreq.bpr_ptr);
 291         } else
 292                 ret = nilfs_bmap_mark_dirty(&direct->d_bmap, ptr);
 293
 294         return ret;
 295 }
 296
 297 static int nilfs_direct_propagate(const struct nilfs_bmap *bmap,
 298                                   struct buffer_head *bh)
 299 {
 300         struct nilfs_direct *direct = (struct nilfs_direct *)bmap;
 301
 302         return NILFS_BMAP_USE_VBN(bmap) ?
 303                 nilfs_direct_propagate_v(direct, bh) : 0;
 304 }
 305
 306 static int nilfs_direct_assign_v(struct nilfs_direct *direct,
 307                                  __u64 key, __u64 ptr,
 308                                  struct buffer_head **bh,
 309                                  sector_t blocknr,
 310                                  union nilfs_binfo *binfo)
 311 {
 312         union nilfs_bmap_ptr_req req;
 313         int ret;
 314
 315         req.bpr_ptr = ptr;
 316         ret = nilfs_bmap_start_v(&direct->d_bmap, &req, blocknr);
 317         if (unlikely(ret < 0))
 318                 return ret;
 319
 320         binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
 321         binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 322
 323         return 0;
 324 }
 325
 326 static int nilfs_direct_assign_p(struct nilfs_direct *direct,
 327                                  __u64 key, __u64 ptr,
 328                                  struct buffer_head **bh,
 329                                  sector_t blocknr,
 330                                  union nilfs_binfo *binfo)
 331 {
 332         nilfs_direct_set_ptr(direct, key, blocknr);
 333
 334         binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 335         binfo->bi_dat.bi_level = 0;
 336
 337         return 0;
 338 }
 339
 340 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
 341                                struct buffer_head **bh,
 342                                sector_t blocknr,
 343                                union nilfs_binfo *binfo)
 344 {
 345         struct nilfs_direct *direct;
 346         __u64 key;
 347         __u64 ptr;
 348
 349         direct = (struct nilfs_direct *)bmap;
 350         key = nilfs_bmap_data_get_key(bmap, *bh);
 351         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
 352                 printk(KERN_CRIT "%s: invalid key: %llu\n", __func__,
 353                        (unsigned long long)key);
 354                 return -EINVAL;
 355         }
 356         ptr = nilfs_direct_get_ptr(direct, key);
 357         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
 358                 printk(KERN_CRIT "%s: invalid pointer: %llu\n", __func__,
 359                        (unsigned long long)ptr);
 360                 return -EINVAL;
 361         }
 362
 363         return NILFS_BMAP_USE_VBN(bmap) ?
 364                 nilfs_direct_assign_v(direct, key, ptr, bh, blocknr, binfo) :
 365                 nilfs_direct_assign_p(direct, key, ptr, bh, blocknr, binfo);
 366 }
 367
 368 static const struct nilfs_bmap_operations nilfs_direct_ops = {
 369         .bop_lookup             =       nilfs_direct_lookup,
 370         .bop_insert             =       nilfs_direct_insert,
 371         .bop_delete             =       nilfs_direct_delete,
 372         .bop_clear              =       NULL,
 373
 374         .bop_propagate          =       nilfs_direct_propagate,
 375
 376         .bop_lookup_dirty_buffers       =       NULL,
 377
 378         .bop_assign             =       nilfs_direct_assign,
 379         .bop_mark               =       NULL,
 380
 381         .bop_last_key           =       nilfs_direct_last_key,
 382         .bop_check_insert       =       nilfs_direct_check_insert,
 383         .bop_check_delete       =       NULL,
 384         .bop_gather_data        =       nilfs_direct_gather_data,
 385 };
 386
 387
 388 int nilfs_direct_init(struct nilfs_bmap *bmap)
 389 {
 390         bmap->b_ops = &nilfs_direct_ops;
 391         return 0;
 392 }