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_bmap *direct)
  31 {
  32         return (__le64 *)
  33                 ((struct nilfs_direct_node *)direct->b_u.u_data + 1);
  34 }
  35
  36 static inline __u64
  37 nilfs_direct_get_ptr(const struct nilfs_bmap *direct, __u64 key)
  38 {
  39         return le64_to_cpu(*(nilfs_direct_dptrs(direct) + key));
  40 }
  41
  42 static inline void nilfs_direct_set_ptr(struct nilfs_bmap *direct,
  43                                         __u64 key, __u64 ptr)
  44 {
  45         *(nilfs_direct_dptrs(direct) + key) = cpu_to_le64(ptr);
  46 }
  47
  48 static int nilfs_direct_lookup(const struct nilfs_bmap *direct,
  49                                __u64 key, int level, __u64 *ptrp)
  50 {
  51         __u64 ptr;
  52
  53         if (key > NILFS_DIRECT_KEY_MAX || level != 1)
  54                 return -ENOENT;
  55         ptr = nilfs_direct_get_ptr(direct, key);
  56         if (ptr == NILFS_BMAP_INVALID_PTR)
  57                 return -ENOENT;
  58
  59         *ptrp = ptr;
  60         return 0;
  61 }
  62
  63 static int nilfs_direct_lookup_contig(const struct nilfs_bmap *direct,
  64                                       __u64 key, __u64 *ptrp,
  65                                       unsigned maxblocks)
  66 {
  67         struct inode *dat = NULL;
  68         __u64 ptr, ptr2;
  69         sector_t blocknr;
  70         int ret, cnt;
  71
  72         if (key > NILFS_DIRECT_KEY_MAX)
  73                 return -ENOENT;
  74         ptr = nilfs_direct_get_ptr(direct, key);
  75         if (ptr == NILFS_BMAP_INVALID_PTR)
  76                 return -ENOENT;
  77
  78         if (NILFS_BMAP_USE_VBN(direct)) {
  79                 dat = nilfs_bmap_get_dat(direct);
  80                 ret = nilfs_dat_translate(dat, ptr, &blocknr);
  81                 if (ret < 0)
  82                         return ret;
  83                 ptr = blocknr;
  84         }
  85
  86         maxblocks = min_t(unsigned, maxblocks, NILFS_DIRECT_KEY_MAX - key + 1);
  87         for (cnt = 1; cnt < maxblocks &&
  88                      (ptr2 = nilfs_direct_get_ptr(direct, key + cnt)) !=
  89                      NILFS_BMAP_INVALID_PTR;
  90              cnt++) {
  91                 if (dat) {
  92                         ret = nilfs_dat_translate(dat, ptr2, &blocknr);
  93                         if (ret < 0)
  94                                 return ret;
  95                         ptr2 = blocknr;
  96                 }
  97                 if (ptr2 != ptr + cnt)
  98                         break;
  99         }
 100         *ptrp = ptr;
 101         return cnt;
 102 }
 103
 104 static __u64
 105 nilfs_direct_find_target_v(const struct nilfs_bmap *direct, __u64 key)
 106 {
 107         __u64 ptr;
 108
 109         ptr = nilfs_bmap_find_target_seq(direct, key);
 110         if (ptr != NILFS_BMAP_INVALID_PTR)
 111                 /* sequential access */
 112                 return ptr;
 113         else
 114                 /* block group */
 115                 return nilfs_bmap_find_target_in_group(direct);
 116 }
 117
 118 static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 119 {
 120         union nilfs_bmap_ptr_req req;
 121         struct inode *dat = NULL;
 122         struct buffer_head *bh;
 123         int ret;
 124
 125         if (key > NILFS_DIRECT_KEY_MAX)
 126                 return -ENOENT;
 127         if (nilfs_direct_get_ptr(bmap, key) != NILFS_BMAP_INVALID_PTR)
 128                 return -EEXIST;
 129
 130         if (NILFS_BMAP_USE_VBN(bmap)) {
 131                 req.bpr_ptr = nilfs_direct_find_target_v(bmap, key);
 132                 dat = nilfs_bmap_get_dat(bmap);
 133         }
 134         ret = nilfs_bmap_prepare_alloc_ptr(bmap, &req, dat);
 135         if (!ret) {
 136                 /* ptr must be a pointer to a buffer head. */
 137                 bh = (struct buffer_head *)((unsigned long)ptr);
 138                 set_buffer_nilfs_volatile(bh);
 139
 140                 nilfs_bmap_commit_alloc_ptr(bmap, &req, dat);
 141                 nilfs_direct_set_ptr(bmap, key, req.bpr_ptr);
 142
 143                 if (!nilfs_bmap_dirty(bmap))
 144                         nilfs_bmap_set_dirty(bmap);
 145
 146                 if (NILFS_BMAP_USE_VBN(bmap))
 147                         nilfs_bmap_set_target_v(bmap, key, req.bpr_ptr);
 148
 149                 nilfs_inode_add_blocks(bmap->b_inode, 1);
 150         }
 151         return ret;
 152 }
 153
 154 static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
 155 {
 156         union nilfs_bmap_ptr_req req;
 157         struct inode *dat;
 158         int ret;
 159
 160         if (key > NILFS_DIRECT_KEY_MAX ||
 161             nilfs_direct_get_ptr(bmap, key) == NILFS_BMAP_INVALID_PTR)
 162                 return -ENOENT;
 163
 164         dat = NILFS_BMAP_USE_VBN(bmap) ? nilfs_bmap_get_dat(bmap) : NULL;
 165         req.bpr_ptr = nilfs_direct_get_ptr(bmap, key);
 166
 167         ret = nilfs_bmap_prepare_end_ptr(bmap, &req, dat);
 168         if (!ret) {
 169                 nilfs_bmap_commit_end_ptr(bmap, &req, dat);
 170                 nilfs_direct_set_ptr(bmap, key, NILFS_BMAP_INVALID_PTR);
 171                 nilfs_inode_sub_blocks(bmap->b_inode, 1);
 172         }
 173         return ret;
 174 }
 175
 176 static int nilfs_direct_seek_key(const struct nilfs_bmap *direct, __u64 start,
 177                                  __u64 *keyp)
 178 {
 179         __u64 key;
 180
 181         for (key = start; key <= NILFS_DIRECT_KEY_MAX; key++) {
 182                 if (nilfs_direct_get_ptr(direct, key) !=
 183                     NILFS_BMAP_INVALID_PTR) {
 184                         *keyp = key;
 185                         return 0;
 186                 }
 187         }
 188         return -ENOENT;
 189 }
 190
 191 static int nilfs_direct_last_key(const struct nilfs_bmap *direct, __u64 *keyp)
 192 {
 193         __u64 key, lastkey;
 194
 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 *direct,
 215                                     __u64 *keys, __u64 *ptrs, int nitems)
 216 {
 217         __u64 key;
 218         __u64 ptr;
 219         int n;
 220
 221         if (nitems > NILFS_DIRECT_NBLOCKS)
 222                 nitems = NILFS_DIRECT_NBLOCKS;
 223         n = 0;
 224         for (key = 0; key < nitems; key++) {
 225                 ptr = nilfs_direct_get_ptr(direct, key);
 226                 if (ptr != NILFS_BMAP_INVALID_PTR) {
 227                         keys[n] = key;
 228                         ptrs[n] = ptr;
 229                         n++;
 230                 }
 231         }
 232         return n;
 233 }
 234
 235 int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
 236                                     __u64 key, __u64 *keys, __u64 *ptrs, int n)
 237 {
 238         __le64 *dptrs;
 239         int ret, i, j;
 240
 241         /* no need to allocate any resource for conversion */
 242
 243         /* delete */
 244         ret = bmap->b_ops->bop_delete(bmap, key);
 245         if (ret < 0)
 246                 return ret;
 247
 248         /* free resources */
 249         if (bmap->b_ops->bop_clear != NULL)
 250                 bmap->b_ops->bop_clear(bmap);
 251
 252         /* convert */
 253         dptrs = nilfs_direct_dptrs(bmap);
 254         for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
 255                 if ((j < n) && (i == keys[j])) {
 256                         dptrs[i] = (i != key) ?
 257                                 cpu_to_le64(ptrs[j]) :
 258                                 NILFS_BMAP_INVALID_PTR;
 259                         j++;
 260                 } else
 261                         dptrs[i] = NILFS_BMAP_INVALID_PTR;
 262         }
 263
 264         nilfs_direct_init(bmap);
 265         return 0;
 266 }
 267
 268 static int nilfs_direct_propagate(struct nilfs_bmap *bmap,
 269                                   struct buffer_head *bh)
 270 {
 271         struct nilfs_palloc_req oldreq, newreq;
 272         struct inode *dat;
 273         __u64 key;
 274         __u64 ptr;
 275         int ret;
 276
 277         if (!NILFS_BMAP_USE_VBN(bmap))
 278                 return 0;
 279
 280         dat = nilfs_bmap_get_dat(bmap);
 281         key = nilfs_bmap_data_get_key(bmap, bh);
 282         ptr = nilfs_direct_get_ptr(bmap, key);
 283         if (!buffer_nilfs_volatile(bh)) {
 284                 oldreq.pr_entry_nr = ptr;
 285                 newreq.pr_entry_nr = ptr;
 286                 ret = nilfs_dat_prepare_update(dat, &oldreq, &newreq);
 287                 if (ret < 0)
 288                         return ret;
 289                 nilfs_dat_commit_update(dat, &oldreq, &newreq,
 290                                         bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 291                 set_buffer_nilfs_volatile(bh);
 292                 nilfs_direct_set_ptr(bmap, key, newreq.pr_entry_nr);
 293         } else
 294                 ret = nilfs_dat_mark_dirty(dat, ptr);
 295
 296         return ret;
 297 }
 298
 299 static int nilfs_direct_assign_v(struct nilfs_bmap *direct,
 300                                  __u64 key, __u64 ptr,
 301                                  struct buffer_head **bh,
 302                                  sector_t blocknr,
 303                                  union nilfs_binfo *binfo)
 304 {
 305         struct inode *dat = nilfs_bmap_get_dat(direct);
 306         union nilfs_bmap_ptr_req req;
 307         int ret;
 308
 309         req.bpr_ptr = ptr;
 310         ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
 311         if (!ret) {
 312                 nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
 313                 binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
 314                 binfo->bi_v.bi_blkoff = cpu_to_le64(key);
 315         }
 316         return ret;
 317 }
 318
 319 static int nilfs_direct_assign_p(struct nilfs_bmap *direct,
 320                                  __u64 key, __u64 ptr,
 321                                  struct buffer_head **bh,
 322                                  sector_t blocknr,
 323                                  union nilfs_binfo *binfo)
 324 {
 325         nilfs_direct_set_ptr(direct, key, blocknr);
 326
 327         binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
 328         binfo->bi_dat.bi_level = 0;
 329
 330         return 0;
 331 }
 332
 333 static int nilfs_direct_assign(struct nilfs_bmap *bmap,
 334                                struct buffer_head **bh,
 335                                sector_t blocknr,
 336                                union nilfs_binfo *binfo)
 337 {
 338         __u64 key;
 339         __u64 ptr;
 340
 341         key = nilfs_bmap_data_get_key(bmap, *bh);
 342         if (unlikely(key > NILFS_DIRECT_KEY_MAX)) {
 343                 printk(KERN_CRIT "%s: invalid key: %llu\n", __func__,
 344                        (unsigned long long)key);
 345                 return -EINVAL;
 346         }
 347         ptr = nilfs_direct_get_ptr(bmap, key);
 348         if (unlikely(ptr == NILFS_BMAP_INVALID_PTR)) {
 349                 printk(KERN_CRIT "%s: invalid pointer: %llu\n", __func__,
 350                        (unsigned long long)ptr);
 351                 return -EINVAL;
 352         }
 353
 354         return NILFS_BMAP_USE_VBN(bmap) ?
 355                 nilfs_direct_assign_v(bmap, key, ptr, bh, blocknr, binfo) :
 356                 nilfs_direct_assign_p(bmap, key, ptr, bh, blocknr, binfo);
 357 }
 358
 359 static const struct nilfs_bmap_operations nilfs_direct_ops = {
 360         .bop_lookup             =       nilfs_direct_lookup,
 361         .bop_lookup_contig      =       nilfs_direct_lookup_contig,
 362         .bop_insert             =       nilfs_direct_insert,
 363         .bop_delete             =       nilfs_direct_delete,
 364         .bop_clear              =       NULL,
 365
 366         .bop_propagate          =       nilfs_direct_propagate,
 367
 368         .bop_lookup_dirty_buffers       =       NULL,
 369
 370         .bop_assign             =       nilfs_direct_assign,
 371         .bop_mark               =       NULL,
 372
 373         .bop_seek_key           =       nilfs_direct_seek_key,
 374         .bop_last_key           =       nilfs_direct_last_key,
 375
 376         .bop_check_insert       =       nilfs_direct_check_insert,
 377         .bop_check_delete       =       NULL,
 378         .bop_gather_data        =       nilfs_direct_gather_data,
 379 };
 380
 381
 382 int nilfs_direct_init(struct nilfs_bmap *bmap)
 383 {
 384         bmap->b_ops = &nilfs_direct_ops;
 385         return 0;
 386 }