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