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 int 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 int, maxblocks,
  83                           NILFS_DIRECT_KEY_MAX - key + 1);
  84         for (cnt = 1; cnt < maxblocks &&
  85                      (ptr2 = nilfs_direct_get_ptr(direct, key + cnt)) !=
  86                      NILFS_BMAP_INVALID_PTR;
  87              cnt++) {
  88                 if (dat) {
  89                         ret = nilfs_dat_translate(dat, ptr2, &blocknr);
  90                         if (ret < 0)
  91                                 return ret;
  92                         ptr2 = blocknr;
  93                 }
  94                 if (ptr2 != ptr + cnt)
  95                         break;
  96         }
  97         *ptrp = ptr;
  98         return cnt;
  99 }
 100
 101 static __u64
 102 nilfs_direct_find_target_v(const struct nilfs_bmap *direct, __u64 key)
 103 {
 104         __u64 ptr;
 105
 106         ptr = nilfs_bmap_find_target_seq(direct, key);
 107         if (ptr != NILFS_BMAP_INVALID_PTR)
 108                 /* sequential access */
 109                 return ptr;
 110
 111         /* block group */
 112         return nilfs_bmap_find_target_in_group(direct);
 113 }
 114
 115 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 116 {
 117         union nilfs_bmap_ptr_req req;
 118         struct inode *dat = NULL;
 119         struct buffer_head *bh;
 120         int ret;
 121
 122         if (key > NILFS_DIRECT_KEY_MAX)
 123                 return -ENOENT;
 124         if (nilfs_direct_get_ptr(bmap, key) != NILFS_BMAP_INVALID_PTR)
 125                 return -EEXIST;
 126
 127         if (NILFS_BMAP_USE_VBN(bmap)) {
 128                 req.bpr_ptr = nilfs_direct_find_target_v(bmap, key);
 129                 dat = nilfs_bmap_get_dat(bmap);
 130         }
 131         ret = nilfs_bmap_prepare_alloc_ptr(bmap, &req, dat);
 132         if (!ret) {
 133                 /* ptr must be a pointer to a buffer head. */
 134                 bh = (struct buffer_head *)((unsigned long)ptr);
 135                 set_buffer_nilfs_volatile(bh);
 136
 137                 nilfs_bmap_commit_alloc_ptr(bmap, &req, dat);
 138                 nilfs_direct_set_ptr(bmap, key, req.bpr_ptr);
 139
 140                 if (!nilfs_bmap_dirty(bmap))
 141                         nilfs_bmap_set_dirty(bmap);
 142
 143                 if (NILFS_BMAP_USE_VBN(bmap))
 144                         nilfs_bmap_set_target_v(bmap, key, req.bpr_ptr);
 145
 146                 nilfs_inode_add_blocks(bmap->b_inode, 1);
 147         }
 148         return ret;
 149 }
 150
 151 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 152 {
 153         union nilfs_bmap_ptr_req req;
 154         struct inode *dat;
 155         int ret;
 156
 157         if (key > NILFS_DIRECT_KEY_MAX ||
 158             nilfs_direct_get_ptr(bmap, key) == NILFS_BMAP_INVALID_PTR)
 159                 return -ENOENT;
 160
 161         dat = NILFS_BMAP_USE_VBN(bmap) ? nilfs_bmap_get_dat(bmap) : NULL;
 162         req.bpr_ptr = nilfs_direct_get_ptr(bmap, key);
 163
 164         ret = nilfs_bmap_prepare_end_ptr(bmap, &req, dat);
 165         if (!ret) {
 166                 nilfs_bmap_commit_end_ptr(bmap, &req, dat);
 167                 nilfs_direct_set_ptr(bmap, key, NILFS_BMAP_INVALID_PTR);
 168                 nilfs_inode_sub_blocks(bmap->b_inode, 1);
 169         }
 170         return ret;
 171 }
 172
 173 static int nilfs_direct_seek_key(const struct nilfs_bmap *direct, __u64 start,
 174                                  __u64 *keyp)
 175 {
 176         __u64 key;
 177
 178         for (key = start; key <= NILFS_DIRECT_KEY_MAX; key++) {
 179                 if (nilfs_direct_get_ptr(direct, key) !=
 180                     NILFS_BMAP_INVALID_PTR) {
 181                         *keyp = key;
 182                         return 0;
 183                 }
 184         }
 185         return -ENOENT;
 186 }
 187
 188 static int nilfs_direct_last_key(const struct nilfs_bmap *direct, __u64 *keyp)
 189 {
 190         __u64 key, lastkey;
 191
 192         lastkey = NILFS_DIRECT_KEY_MAX + 1;
 193         for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
 194                 if (nilfs_direct_get_ptr(direct, key) !=
 195                     NILFS_BMAP_INVALID_PTR)
 196                         lastkey = key;
 197
 198         if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
 199                 return -ENOENT;
 200
 201         *keyp = lastkey;
 202
 203         return 0;
 204 }
 205
 206 static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
 207 {
 208         return key > NILFS_DIRECT_KEY_MAX;
 209 }
 210
 211 static int nilfs_direct_gather_data(struct nilfs_bmap *direct,
 212                                     __u64 *keys, __u64 *ptrs, int nitems)
 213 {
 214         __u64 key;
 215         __u64 ptr;
 216         int n;
 217
 218         if (nitems > NILFS_DIRECT_NBLOCKS)
 219                 nitems = NILFS_DIRECT_NBLOCKS;
 220         n = 0;
 221         for (key = 0; key < nitems; key++) {
 222                 ptr = nilfs_direct_get_ptr(direct, key);
 223                 if (ptr != NILFS_BMAP_INVALID_PTR) {
 224                         keys[n] = key;
 225                         ptrs[n] = ptr;
 226                         n++;
 227                 }
 228         }
 229         return n;
 230 }
 231
 232 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
 233                                     __u64 key, __u64 *keys, __u64 *ptrs, int n)
 234 {
 235         __le64 *dptrs;
 236         int ret, i, j;
 237
 238         /* no need to allocate any resource for conversion */
 239
 240         /* delete */
 241         ret = bmap->b_ops->bop_delete(bmap, key);
 242         if (ret < 0)
 243                 return ret;
 244
 245         /* free resources */
 246         if (bmap->b_ops->bop_clear != NULL)
 247                 bmap->b_ops->bop_clear(bmap);
 248
 249         /* convert */
 250         dptrs = nilfs_direct_dptrs(bmap);
 251         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
 252                 if ((j < n) && (i == keys[j])) {
 253                         dptrs[i] = (i != key) ?
 254                                 cpu_to_le64(ptrs[j]) :
 255                                 NILFS_BMAP_INVALID_PTR;
 256                         j++;
 257                 } else
 258                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
 259         }
 260
 261         nilfs_direct_init(bmap);
 262         return 0;
 263 }
 264
 265 static int nilfs_direct_propagate(struct nilfs_bmap *bmap,
 266                                   struct buffer_head *bh)
 267 {
 268         struct nilfs_palloc_req oldreq, newreq;
 269         struct inode *dat;
 270         __u64 key;
 271         __u64 ptr;
 272         int ret;
 273
 274         if (!NILFS_BMAP_USE_VBN(bmap))
 275                 return 0;
 276
 277         dat = nilfs_bmap_get_dat(bmap);
 278         key = nilfs_bmap_data_get_key(bmap, bh);
 279         ptr = nilfs_direct_get_ptr(bmap, key);
 280         if (!buffer_nilfs_volatile(bh)) {
 281                 oldreq.pr_entry_nr = ptr;
 282                 newreq.pr_entry_nr = ptr;
 283                 ret = nilfs_dat_prepare_update(dat, &oldreq, &newreq);
 284                 if (ret < 0)
 285                         return ret;
 286                 nilfs_dat_commit_update(dat, &oldreq, &newreq,
 287                                         bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 288                 set_buffer_nilfs_volatile(bh);
 289                 nilfs_direct_set_ptr(bmap, key, newreq.pr_entry_nr);
 290         } else
 291                 ret = nilfs_dat_mark_dirty(dat, ptr);
 292
 293         return ret;
 294 }
 295
 296 static int nilfs_direct_assign_v(struct nilfs_bmap *direct,
 297                                  __u64 key, __u64 ptr,
 298                                  struct buffer_head **bh,
 299                                  sector_t blocknr,
 300                                  union nilfs_binfo *binfo)
 301 {
 302         struct inode *dat = nilfs_bmap_get_dat(direct);
 303         union nilfs_bmap_ptr_req req;
 304         int ret;
 305
 306         req.bpr_ptr = ptr;
 307         ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
 308         if (!ret) {
 309                 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
 310                 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
 311                 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
 312         }
 313         return ret;
 314 }
 315
 316 static int nilfs_direct_assign_p(struct nilfs_bmap *direct,
 317                                  __u64 key, __u64 ptr,
 318                                  struct buffer_head **bh,
 319                                  sector_t blocknr,
 320                                  union nilfs_binfo *binfo)
 321 {
 322         nilfs_direct_set_ptr(direct, key, blocknr);
 323
 324         binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
 325         binfo->bi_dat.bi_level = 0;
 326
 327         return 0;
 328 }
 329
 330 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
 331                                struct buffer_head **bh,
 332                                sector_t blocknr,
 333                                union nilfs_binfo *binfo)
 334 {
 335         __u64 key;
 336         __u64 ptr;
 337
 338         key = nilfs_bmap_data_get_key(bmap, *bh);
 339         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
 340                 nilfs_msg(bmap->b_inode->i_sb, KERN_CRIT,
 341                           "%s (ino=%lu): invalid key: %llu", __func__,
 342                           bmap->b_inode->i_ino, (unsigned long long)key);
 343                 return -EINVAL;
 344         }
 345         ptr = nilfs_direct_get_ptr(bmap, key);
 346         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
 347                 nilfs_msg(bmap->b_inode->i_sb, KERN_CRIT,
 348                           "%s (ino=%lu): invalid pointer: %llu", __func__,
 349                           bmap->b_inode->i_ino, (unsigned long long)ptr);
 350                 return -EINVAL;
 351         }
 352
 353         return NILFS_BMAP_USE_VBN(bmap) ?
 354                 nilfs_direct_assign_v(bmap, key, ptr, bh, blocknr, binfo) :
 355                 nilfs_direct_assign_p(bmap, key, ptr, bh, blocknr, binfo);
 356 }
 357
 358 static const struct nilfs_bmap_operations nilfs_direct_ops = {
 359         .bop_lookup             =       nilfs_direct_lookup,
 360         .bop_lookup_contig      =       nilfs_direct_lookup_contig,
 361         .bop_insert             =       nilfs_direct_insert,
 362         .bop_delete             =       nilfs_direct_delete,
 363         .bop_clear              =       NULL,
 364
 365         .bop_propagate          =       nilfs_direct_propagate,
 366
 367         .bop_lookup_dirty_buffers       =       NULL,
 368
 369         .bop_assign             =       nilfs_direct_assign,
 370         .bop_mark               =       NULL,
 371
 372         .bop_seek_key           =       nilfs_direct_seek_key,
 373         .bop_last_key           =       nilfs_direct_last_key,
 374
 375         .bop_check_insert       =       nilfs_direct_check_insert,
 376         .bop_check_delete       =       NULL,
 377         .bop_gather_data        =       nilfs_direct_gather_data,
 378 };
 379
 380
 381 int nilfs_direct_init(struct nilfs_bmap *bmap)
 382 {
 383         bmap->b_ops = &nilfs_direct_ops;
 384         return 0;
 385 }