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  * Written by Koji Sato.
  17  */
  18
  19 #include <linux/errno.h>
  20 #include "nilfs.h"
  21 #include "page.h"
  22 #include "direct.h"
  23 #include "alloc.h"
  24 #include "dat.h"
  25
  26 static inline __le64 *nilfs_direct_dptrs(const struct nilfs_bmap *direct)
  27 {
  28         return (__le64 *)
  29                 ((struct nilfs_direct_node *)direct->b_u.u_data + 1);
  30 }
  31
  32 static inline __u64
  33 nilfs_direct_get_ptr(const struct nilfs_bmap *direct, __u64 key)
  34 {
  35         return le64_to_cpu(*(nilfs_direct_dptrs(direct) + key));
  36 }
  37
  38 static inline void nilfs_direct_set_ptr(struct nilfs_bmap *direct,
  39                                         __u64 key, __u64 ptr)
  40 {
  41         *(nilfs_direct_dptrs(direct) + key) = cpu_to_le64(ptr);
  42 }
  43
  44 static int nilfs_direct_lookup(const struct nilfs_bmap *direct,
  45                                __u64 key, int level, __u64 *ptrp)
  46 {
  47         __u64 ptr;
  48
  49         if (key > NILFS_DIRECT_KEY_MAX || level != 1)
  50                 return -ENOENT;
  51         ptr = nilfs_direct_get_ptr(direct, key);
  52         if (ptr == NILFS_BMAP_INVALID_PTR)
  53                 return -ENOENT;
  54
  55         *ptrp = ptr;
  56         return 0;
  57 }
  58
  59 static int nilfs_direct_lookup_contig(const struct nilfs_bmap *direct,
  60                                       __u64 key, __u64 *ptrp,
  61                                       unsigned maxblocks)
  62 {
  63         struct inode *dat = NULL;
  64         __u64 ptr, ptr2;
  65         sector_t blocknr;
  66         int ret, cnt;
  67
  68         if (key > NILFS_DIRECT_KEY_MAX)
  69                 return -ENOENT;
  70         ptr = nilfs_direct_get_ptr(direct, key);
  71         if (ptr == NILFS_BMAP_INVALID_PTR)
  72                 return -ENOENT;
  73
  74         if (NILFS_BMAP_USE_VBN(direct)) {
  75                 dat = nilfs_bmap_get_dat(direct);
  76                 ret = nilfs_dat_translate(dat, ptr, &blocknr);
  77                 if (ret < 0)
  78                         return ret;
  79                 ptr = blocknr;
  80         }
  81
  82         maxblocks = min_t(unsigned, maxblocks, NILFS_DIRECT_KEY_MAX - key + 1);
  83         for (cnt = 1; cnt < maxblocks &&
  84                      (ptr2 = nilfs_direct_get_ptr(direct, key + cnt)) !=
  85                      NILFS_BMAP_INVALID_PTR;
  86              cnt++) {
  87                 if (dat) {
  88                         ret = nilfs_dat_translate(dat, ptr2, &blocknr);
  89                         if (ret < 0)
  90                                 return ret;
  91                         ptr2 = blocknr;
  92                 }
  93                 if (ptr2 != ptr + cnt)
  94                         break;
  95         }
  96         *ptrp = ptr;
  97         return cnt;
  98 }
  99
 100 static __u64
 101 nilfs_direct_find_target_v(const struct nilfs_bmap *direct, __u64 key)
 102 {
 103         __u64 ptr;
 104
 105         ptr = nilfs_bmap_find_target_seq(direct, key);
 106         if (ptr != NILFS_BMAP_INVALID_PTR)
 107                 /* sequential access */
 108                 return ptr;
 109         else
 110                 /* block group */
 111                 return nilfs_bmap_find_target_in_group(direct);
 112 }
 113
 114 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 115 {
 116         union nilfs_bmap_ptr_req req;
 117         struct inode *dat = NULL;
 118         struct buffer_head *bh;
 119         int ret;
 120
 121         if (key > NILFS_DIRECT_KEY_MAX)
 122                 return -ENOENT;
 123         if (nilfs_direct_get_ptr(bmap, key) != NILFS_BMAP_INVALID_PTR)
 124                 return -EEXIST;
 125
 126         if (NILFS_BMAP_USE_VBN(bmap)) {
 127                 req.bpr_ptr = nilfs_direct_find_target_v(bmap, key);
 128                 dat = nilfs_bmap_get_dat(bmap);
 129         }
 130         ret = nilfs_bmap_prepare_alloc_ptr(bmap, &req, dat);
 131         if (!ret) {
 132                 /* ptr must be a pointer to a buffer head. */
 133                 bh = (struct buffer_head *)((unsigned long)ptr);
 134                 set_buffer_nilfs_volatile(bh);
 135
 136                 nilfs_bmap_commit_alloc_ptr(bmap, &req, dat);
 137                 nilfs_direct_set_ptr(bmap, key, req.bpr_ptr);
 138
 139                 if (!nilfs_bmap_dirty(bmap))
 140                         nilfs_bmap_set_dirty(bmap);
 141
 142                 if (NILFS_BMAP_USE_VBN(bmap))
 143                         nilfs_bmap_set_target_v(bmap, key, req.bpr_ptr);
 144
 145                 nilfs_inode_add_blocks(bmap->b_inode, 1);
 146         }
 147         return ret;
 148 }
 149
 150 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 151 {
 152         union nilfs_bmap_ptr_req req;
 153         struct inode *dat;
 154         int ret;
 155
 156         if (key > NILFS_DIRECT_KEY_MAX ||
 157             nilfs_direct_get_ptr(bmap, key) == NILFS_BMAP_INVALID_PTR)
 158                 return -ENOENT;
 159
 160         dat = NILFS_BMAP_USE_VBN(bmap) ? nilfs_bmap_get_dat(bmap) : NULL;
 161         req.bpr_ptr = nilfs_direct_get_ptr(bmap, key);
 162
 163         ret = nilfs_bmap_prepare_end_ptr(bmap, &req, dat);
 164         if (!ret) {
 165                 nilfs_bmap_commit_end_ptr(bmap, &req, dat);
 166                 nilfs_direct_set_ptr(bmap, key, NILFS_BMAP_INVALID_PTR);
 167                 nilfs_inode_sub_blocks(bmap->b_inode, 1);
 168         }
 169         return ret;
 170 }
 171
 172 static int nilfs_direct_seek_key(const struct nilfs_bmap *direct, __u64 start,
 173                                  __u64 *keyp)
 174 {
 175         __u64 key;
 176
 177         for (key = start; key <= NILFS_DIRECT_KEY_MAX; key++) {
 178                 if (nilfs_direct_get_ptr(direct, key) !=
 179                     NILFS_BMAP_INVALID_PTR) {
 180                         *keyp = key;
 181                         return 0;
 182                 }
 183         }
 184         return -ENOENT;
 185 }
 186
 187 static int nilfs_direct_last_key(const struct nilfs_bmap *direct, __u64 *keyp)
 188 {
 189         __u64 key, lastkey;
 190
 191         lastkey = NILFS_DIRECT_KEY_MAX + 1;
 192         for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
 193                 if (nilfs_direct_get_ptr(direct, key) !=
 194                     NILFS_BMAP_INVALID_PTR)
 195                         lastkey = key;
 196
 197         if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
 198                 return -ENOENT;
 199
 200         *keyp = lastkey;
 201
 202         return 0;
 203 }
 204
 205 static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
 206 {
 207         return key > NILFS_DIRECT_KEY_MAX;
 208 }
 209
 210 static int nilfs_direct_gather_data(struct nilfs_bmap *direct,
 211                                     __u64 *keys, __u64 *ptrs, int nitems)
 212 {
 213         __u64 key;
 214         __u64 ptr;
 215         int n;
 216
 217         if (nitems > NILFS_DIRECT_NBLOCKS)
 218                 nitems = NILFS_DIRECT_NBLOCKS;
 219         n = 0;
 220         for (key = 0; key < nitems; key++) {
 221                 ptr = nilfs_direct_get_ptr(direct, key);
 222                 if (ptr != NILFS_BMAP_INVALID_PTR) {
 223                         keys[n] = key;
 224                         ptrs[n] = ptr;
 225                         n++;
 226                 }
 227         }
 228         return n;
 229 }
 230
 231 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
 232                                     __u64 key, __u64 *keys, __u64 *ptrs, int n)
 233 {
 234         __le64 *dptrs;
 235         int ret, i, j;
 236
 237         /* no need to allocate any resource for conversion */
 238
 239         /* delete */
 240         ret = bmap->b_ops->bop_delete(bmap, key);
 241         if (ret < 0)
 242                 return ret;
 243
 244         /* free resources */
 245         if (bmap->b_ops->bop_clear != NULL)
 246                 bmap->b_ops->bop_clear(bmap);
 247
 248         /* convert */
 249         dptrs = nilfs_direct_dptrs(bmap);
 250         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
 251                 if ((j < n) && (i == keys[j])) {
 252                         dptrs[i] = (i != key) ?
 253                                 cpu_to_le64(ptrs[j]) :
 254                                 NILFS_BMAP_INVALID_PTR;
 255                         j++;
 256                 } else
 257                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
 258         }
 259
 260         nilfs_direct_init(bmap);
 261         return 0;
 262 }
 263
 264 static int nilfs_direct_propagate(struct nilfs_bmap *bmap,
 265                                   struct buffer_head *bh)
 266 {
 267         struct nilfs_palloc_req oldreq, newreq;
 268         struct inode *dat;
 269         __u64 key;
 270         __u64 ptr;
 271         int ret;
 272
 273         if (!NILFS_BMAP_USE_VBN(bmap))
 274                 return 0;
 275
 276         dat = nilfs_bmap_get_dat(bmap);
 277         key = nilfs_bmap_data_get_key(bmap, bh);
 278         ptr = nilfs_direct_get_ptr(bmap, key);
 279         if (!buffer_nilfs_volatile(bh)) {
 280                 oldreq.pr_entry_nr = ptr;
 281                 newreq.pr_entry_nr = ptr;
 282                 ret = nilfs_dat_prepare_update(dat, &oldreq, &newreq);
 283                 if (ret < 0)
 284                         return ret;
 285                 nilfs_dat_commit_update(dat, &oldreq, &newreq,
 286                                         bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 287                 set_buffer_nilfs_volatile(bh);
 288                 nilfs_direct_set_ptr(bmap, key, newreq.pr_entry_nr);
 289         } else
 290                 ret = nilfs_dat_mark_dirty(dat, ptr);
 291
 292         return ret;
 293 }
 294
 295 static int nilfs_direct_assign_v(struct nilfs_bmap *direct,
 296                                  __u64 key, __u64 ptr,
 297                                  struct buffer_head **bh,
 298                                  sector_t blocknr,
 299                                  union nilfs_binfo *binfo)
 300 {
 301         struct inode *dat = nilfs_bmap_get_dat(direct);
 302         union nilfs_bmap_ptr_req req;
 303         int ret;
 304
 305         req.bpr_ptr = ptr;
 306         ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
 307         if (!ret) {
 308                 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
 309                 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
 310                 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
 311         }
 312         return ret;
 313 }
 314
 315 static int nilfs_direct_assign_p(struct nilfs_bmap *direct,
 316                                  __u64 key, __u64 ptr,
 317                                  struct buffer_head **bh,
 318                                  sector_t blocknr,
 319                                  union nilfs_binfo *binfo)
 320 {
 321         nilfs_direct_set_ptr(direct, key, blocknr);
 322
 323         binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
 324         binfo->bi_dat.bi_level = 0;
 325
 326         return 0;
 327 }
 328
 329 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
 330                                struct buffer_head **bh,
 331                                sector_t blocknr,
 332                                union nilfs_binfo *binfo)
 333 {
 334         __u64 key;
 335         __u64 ptr;
 336
 337         key = nilfs_bmap_data_get_key(bmap, *bh);
 338         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
 339                 printk(KERN_CRIT "%s: invalid key: %llu\n", __func__,
 340                        (unsigned long long)key);
 341                 return -EINVAL;
 342         }
 343         ptr = nilfs_direct_get_ptr(bmap, key);
 344         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
 345                 printk(KERN_CRIT "%s: invalid pointer: %llu\n", __func__,
 346                        (unsigned long long)ptr);
 347                 return -EINVAL;
 348         }
 349
 350         return NILFS_BMAP_USE_VBN(bmap) ?
 351                 nilfs_direct_assign_v(bmap, key, ptr, bh, blocknr, binfo) :
 352                 nilfs_direct_assign_p(bmap, key, ptr, bh, blocknr, binfo);
 353 }
 354
 355 static const struct nilfs_bmap_operations nilfs_direct_ops = {
 356         .bop_lookup             =       nilfs_direct_lookup,
 357         .bop_lookup_contig      =       nilfs_direct_lookup_contig,
 358         .bop_insert             =       nilfs_direct_insert,
 359         .bop_delete             =       nilfs_direct_delete,
 360         .bop_clear              =       NULL,
 361
 362         .bop_propagate          =       nilfs_direct_propagate,
 363
 364         .bop_lookup_dirty_buffers       =       NULL,
 365
 366         .bop_assign             =       nilfs_direct_assign,
 367         .bop_mark               =       NULL,
 368
 369         .bop_seek_key           =       nilfs_direct_seek_key,
 370         .bop_last_key           =       nilfs_direct_last_key,
 371
 372         .bop_check_insert       =       nilfs_direct_check_insert,
 373         .bop_check_delete       =       NULL,
 374         .bop_gather_data        =       nilfs_direct_gather_data,
 375 };
 376
 377
 378 int nilfs_direct_init(struct nilfs_bmap *bmap)
 379 {
 380         bmap->b_ops = &nilfs_direct_ops;
 381         return 0;
 382 }