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;
  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_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 129 {
 130         struct nilfs_direct *direct = (struct nilfs_direct *)bmap;
 131         union nilfs_bmap_ptr_req req;
 132         struct inode *dat = NULL;
 133         struct buffer_head *bh;
 134         int ret;
 135
 136         if (key > NILFS_DIRECT_KEY_MAX)
 137                 return -ENOENT;
 138         if (nilfs_direct_get_ptr(direct, key) != NILFS_BMAP_INVALID_PTR)
 139                 return -EEXIST;
 140
 141         if (NILFS_BMAP_USE_VBN(bmap)) {
 142                 req.bpr_ptr = nilfs_direct_find_target_v(direct, key);
 143                 dat = nilfs_bmap_get_dat(bmap);
 144         }
 145         ret = nilfs_bmap_prepare_alloc_ptr(bmap, &req, dat);
 146         if (!ret) {
 147                 /* ptr must be a pointer to a buffer head. */
 148                 bh = (struct buffer_head *)((unsigned long)ptr);
 149                 set_buffer_nilfs_volatile(bh);
 150
 151                 nilfs_bmap_commit_alloc_ptr(bmap, &req, dat);
 152                 nilfs_direct_set_ptr(direct, key, req.bpr_ptr);
 153
 154                 if (!nilfs_bmap_dirty(bmap))
 155                         nilfs_bmap_set_dirty(bmap);
 156
 157                 if (NILFS_BMAP_USE_VBN(bmap))
 158                         nilfs_direct_set_target_v(direct, key, req.bpr_ptr);
 159
 160                 nilfs_bmap_add_blocks(bmap, 1);
 161         }
 162         return ret;
 163 }
 164
 165 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 166 {
 167         struct nilfs_direct *direct = (struct nilfs_direct *)bmap;
 168         union nilfs_bmap_ptr_req req;
 169         struct inode *dat;
 170         int ret;
 171
 172         if (key > NILFS_DIRECT_KEY_MAX ||
 173             nilfs_direct_get_ptr(direct, key) == NILFS_BMAP_INVALID_PTR)
 174                 return -ENOENT;
 175
 176         dat = NILFS_BMAP_USE_VBN(bmap) ? nilfs_bmap_get_dat(bmap) : NULL;
 177         req.bpr_ptr = nilfs_direct_get_ptr(direct, key);
 178
 179         ret = nilfs_bmap_prepare_end_ptr(bmap, &req, dat);
 180         if (!ret) {
 181                 nilfs_bmap_commit_end_ptr(bmap, &req, dat);
 182                 nilfs_direct_set_ptr(direct, key, NILFS_BMAP_INVALID_PTR);
 183                 nilfs_bmap_sub_blocks(bmap, 1);
 184         }
 185         return ret;
 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(const struct nilfs_bmap *bmap,
 272                                   struct buffer_head *bh)
 273 {
 274         struct nilfs_direct *direct = (struct nilfs_direct *)bmap;
 275         struct nilfs_palloc_req oldreq, newreq;
 276         struct inode *dat;
 277         __u64 key;
 278         __u64 ptr;
 279         int ret;
 280
 281         if (!NILFS_BMAP_USE_VBN(bmap))
 282                 return 0;
 283
 284         dat = nilfs_bmap_get_dat(bmap);
 285         key = nilfs_bmap_data_get_key(bmap, bh);
 286         ptr = nilfs_direct_get_ptr(direct, key);
 287         if (!buffer_nilfs_volatile(bh)) {
 288                 oldreq.pr_entry_nr = ptr;
 289                 newreq.pr_entry_nr = ptr;
 290                 ret = nilfs_dat_prepare_update(dat, &oldreq, &newreq);
 291                 if (ret < 0)
 292                         return ret;
 293                 nilfs_dat_commit_update(dat, &oldreq, &newreq,
 294                                         bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 295                 set_buffer_nilfs_volatile(bh);
 296                 nilfs_direct_set_ptr(direct, key, newreq.pr_entry_nr);
 297         } else
 298                 ret = nilfs_dat_mark_dirty(dat, ptr);
 299
 300         return ret;
 301 }
 302
 303 static int nilfs_direct_assign_v(struct nilfs_direct *direct,
 304                                  __u64 key, __u64 ptr,
 305                                  struct buffer_head **bh,
 306                                  sector_t blocknr,
 307                                  union nilfs_binfo *binfo)
 308 {
 309         struct inode *dat = nilfs_bmap_get_dat(&direct->d_bmap);
 310         union nilfs_bmap_ptr_req req;
 311         int ret;
 312
 313         req.bpr_ptr = ptr;
 314         ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
 315         if (!ret) {
 316                 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
 317                 binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
 318                 binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 319         }
 320         return ret;
 321 }
 322
 323 static int nilfs_direct_assign_p(struct nilfs_direct *direct,
 324                                  __u64 key, __u64 ptr,
 325                                  struct buffer_head **bh,
 326                                  sector_t blocknr,
 327                                  union nilfs_binfo *binfo)
 328 {
 329         nilfs_direct_set_ptr(direct, key, blocknr);
 330
 331         binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
 332         binfo->bi_dat.bi_level = 0;
 333
 334         return 0;
 335 }
 336
 337 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
 338                                struct buffer_head **bh,
 339                                sector_t blocknr,
 340                                union nilfs_binfo *binfo)
 341 {
 342         struct nilfs_direct *direct;
 343         __u64 key;
 344         __u64 ptr;
 345
 346         direct = (struct nilfs_direct *)bmap;
 347         key = nilfs_bmap_data_get_key(bmap, *bh);
 348         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
 349                 printk(KERN_CRIT "%s: invalid key: %llu\n", __func__,
 350                        (unsigned long long)key);
 351                 return -EINVAL;
 352         }
 353         ptr = nilfs_direct_get_ptr(direct, key);
 354         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
 355                 printk(KERN_CRIT "%s: invalid pointer: %llu\n", __func__,
 356                        (unsigned long long)ptr);
 357                 return -EINVAL;
 358         }
 359
 360         return NILFS_BMAP_USE_VBN(bmap) ?
 361                 nilfs_direct_assign_v(direct, key, ptr, bh, blocknr, binfo) :
 362                 nilfs_direct_assign_p(direct, key, ptr, bh, blocknr, binfo);
 363 }
 364
 365 static const struct nilfs_bmap_operations nilfs_direct_ops = {
 366         .bop_lookup             =       nilfs_direct_lookup,
 367         .bop_lookup_contig      =       nilfs_direct_lookup_contig,
 368         .bop_insert             =       nilfs_direct_insert,
 369         .bop_delete             =       nilfs_direct_delete,
 370         .bop_clear              =       NULL,
 371
 372         .bop_propagate          =       nilfs_direct_propagate,
 373
 374         .bop_lookup_dirty_buffers       =       NULL,
 375
 376         .bop_assign             =       nilfs_direct_assign,
 377         .bop_mark               =       NULL,
 378
 379         .bop_last_key           =       nilfs_direct_last_key,
 380         .bop_check_insert       =       nilfs_direct_check_insert,
 381         .bop_check_delete       =       NULL,
 382         .bop_gather_data        =       nilfs_direct_gather_data,
 383 };
 384
 385
 386 int nilfs_direct_init(struct nilfs_bmap *bmap)
 387 {
 388         bmap->b_ops = &nilfs_direct_ops;
 389         return 0;
 390 }