fs/nilfs2/dat.c

   1 /*
   2  * dat.c - NILFS disk address translation.
   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/types.h>
  24 #include <linux/buffer_head.h>
  25 #include <linux/string.h>
  26 #include <linux/errno.h>
  27 #include "nilfs.h"
  28 #include "mdt.h"
  29 #include "alloc.h"
  30 #include "dat.h"
  31
  32
  33 #define NILFS_CNO_MIN   ((__u64)1)
  34 #define NILFS_CNO_MAX   (~(__u64)0)
  35
  36 /**
  37  * struct nilfs_dat_info - on-memory private data of DAT file
  38  * @mi: on-memory private data of metadata file
  39  * @palloc_cache: persistent object allocator cache of DAT file
  40  * @shadow: shadow map of DAT file
  41  */
  42 struct nilfs_dat_info {
  43         struct nilfs_mdt_info mi;
  44         struct nilfs_palloc_cache palloc_cache;
  45         struct nilfs_shadow_map shadow;
  46 };
  47
  48 static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
  49 {
  50         return (struct nilfs_dat_info *)NILFS_MDT(dat);
  51 }
  52
  53 static int nilfs_dat_prepare_entry(struct inode *dat,
  54                                    struct nilfs_palloc_req *req, int create)
  55 {
  56         return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
  57                                             create, &req->pr_entry_bh);
  58 }
  59
  60 static void nilfs_dat_commit_entry(struct inode *dat,
  61                                    struct nilfs_palloc_req *req)
  62 {
  63         mark_buffer_dirty(req->pr_entry_bh);
  64         nilfs_mdt_mark_dirty(dat);
  65         brelse(req->pr_entry_bh);
  66 }
  67
  68 static void nilfs_dat_abort_entry(struct inode *dat,
  69                                   struct nilfs_palloc_req *req)
  70 {
  71         brelse(req->pr_entry_bh);
  72 }
  73
  74 int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
  75 {
  76         int ret;
  77
  78         ret = nilfs_palloc_prepare_alloc_entry(dat, req);
  79         if (ret < 0)
  80                 return ret;
  81
  82         ret = nilfs_dat_prepare_entry(dat, req, 1);
  83         if (ret < 0)
  84                 nilfs_palloc_abort_alloc_entry(dat, req);
  85
  86         return ret;
  87 }
  88
  89 void nilfs_dat_commit_alloc(struct inode *dat, struct nilfs_palloc_req *req)
  90 {
  91         struct nilfs_dat_entry *entry;
  92         void *kaddr;
  93
  94         kaddr = kmap_atomic(req->pr_entry_bh->b_page);
  95         entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
  96                                              req->pr_entry_bh, kaddr);
  97         entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
  98         entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
  99         entry->de_blocknr = cpu_to_le64(0);
 100         kunmap_atomic(kaddr);
 101
 102         nilfs_palloc_commit_alloc_entry(dat, req);
 103         nilfs_dat_commit_entry(dat, req);
 104 }
 105
 106 void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 107 {
 108         nilfs_dat_abort_entry(dat, req);
 109         nilfs_palloc_abort_alloc_entry(dat, req);
 110 }
 111
 112 static void nilfs_dat_commit_free(struct inode *dat,
 113                                   struct nilfs_palloc_req *req)
 114 {
 115         struct nilfs_dat_entry *entry;
 116         void *kaddr;
 117
 118         kaddr = kmap_atomic(req->pr_entry_bh->b_page);
 119         entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 120                                              req->pr_entry_bh, kaddr);
 121         entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
 122         entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
 123         entry->de_blocknr = cpu_to_le64(0);
 124         kunmap_atomic(kaddr);
 125
 126         nilfs_dat_commit_entry(dat, req);
 127         nilfs_palloc_commit_free_entry(dat, req);
 128 }
 129
 130 int nilfs_dat_prepare_start(struct inode *dat, struct nilfs_palloc_req *req)
 131 {
 132         int ret;
 133
 134         ret = nilfs_dat_prepare_entry(dat, req, 0);
 135         WARN_ON(ret == -ENOENT);
 136         return ret;
 137 }
 138
 139 void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
 140                             sector_t blocknr)
 141 {
 142         struct nilfs_dat_entry *entry;
 143         void *kaddr;
 144
 145         kaddr = kmap_atomic(req->pr_entry_bh->b_page);
 146         entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 147                                              req->pr_entry_bh, kaddr);
 148         entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
 149         entry->de_blocknr = cpu_to_le64(blocknr);
 150         kunmap_atomic(kaddr);
 151
 152         nilfs_dat_commit_entry(dat, req);
 153 }
 154
 155 int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)
 156 {
 157         struct nilfs_dat_entry *entry;
 158         sector_t blocknr;
 159         void *kaddr;
 160         int ret;
 161
 162         ret = nilfs_dat_prepare_entry(dat, req, 0);
 163         if (ret < 0) {
 164                 WARN_ON(ret == -ENOENT);
 165                 return ret;
 166         }
 167
 168         kaddr = kmap_atomic(req->pr_entry_bh->b_page);
 169         entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 170                                              req->pr_entry_bh, kaddr);
 171         blocknr = le64_to_cpu(entry->de_blocknr);
 172         kunmap_atomic(kaddr);
 173
 174         if (blocknr == 0) {
 175                 ret = nilfs_palloc_prepare_free_entry(dat, req);
 176                 if (ret < 0) {
 177                         nilfs_dat_abort_entry(dat, req);
 178                         return ret;
 179                 }
 180         }
 181
 182         return 0;
 183 }
 184
 185 void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
 186                           int dead)
 187 {
 188         struct nilfs_dat_entry *entry;
 189         __u64 start, end;
 190         sector_t blocknr;
 191         void *kaddr;
 192
 193         kaddr = kmap_atomic(req->pr_entry_bh->b_page);
 194         entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 195                                              req->pr_entry_bh, kaddr);
 196         end = start = le64_to_cpu(entry->de_start);
 197         if (!dead) {
 198                 end = nilfs_mdt_cno(dat);
 199                 WARN_ON(start > end);
 200         }
 201         entry->de_end = cpu_to_le64(end);
 202         blocknr = le64_to_cpu(entry->de_blocknr);
 203         kunmap_atomic(kaddr);
 204
 205         if (blocknr == 0)
 206                 nilfs_dat_commit_free(dat, req);
 207         else
 208                 nilfs_dat_commit_entry(dat, req);
 209 }
 210
 211 void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
 212 {
 213         struct nilfs_dat_entry *entry;
 214         __u64 start;
 215         sector_t blocknr;
 216         void *kaddr;
 217
 218         kaddr = kmap_atomic(req->pr_entry_bh->b_page);
 219         entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 220                                              req->pr_entry_bh, kaddr);
 221         start = le64_to_cpu(entry->de_start);
 222         blocknr = le64_to_cpu(entry->de_blocknr);
 223         kunmap_atomic(kaddr);
 224
 225         if (start == nilfs_mdt_cno(dat) && blocknr == 0)
 226                 nilfs_palloc_abort_free_entry(dat, req);
 227         nilfs_dat_abort_entry(dat, req);
 228 }
 229
 230 int nilfs_dat_prepare_update(struct inode *dat,
 231                              struct nilfs_palloc_req *oldreq,
 232                              struct nilfs_palloc_req *newreq)
 233 {
 234         int ret;
 235
 236         ret = nilfs_dat_prepare_end(dat, oldreq);
 237         if (!ret) {
 238                 ret = nilfs_dat_prepare_alloc(dat, newreq);
 239                 if (ret < 0)
 240                         nilfs_dat_abort_end(dat, oldreq);
 241         }
 242         return ret;
 243 }
 244
 245 void nilfs_dat_commit_update(struct inode *dat,
 246                              struct nilfs_palloc_req *oldreq,
 247                              struct nilfs_palloc_req *newreq, int dead)
 248 {
 249         nilfs_dat_commit_end(dat, oldreq, dead);
 250         nilfs_dat_commit_alloc(dat, newreq);
 251 }
 252
 253 void nilfs_dat_abort_update(struct inode *dat,
 254                             struct nilfs_palloc_req *oldreq,
 255                             struct nilfs_palloc_req *newreq)
 256 {
 257         nilfs_dat_abort_end(dat, oldreq);
 258         nilfs_dat_abort_alloc(dat, newreq);
 259 }
 260
 261 /**
 262  * nilfs_dat_mark_dirty -
 263  * @dat: DAT file inode
 264  * @vblocknr: virtual block number
 265  *
 266  * Description:
 267  *
 268  * Return Value: On success, 0 is returned. On error, one of the following
 269  * negative error codes is returned.
 270  *
 271  * %-EIO - I/O error.
 272  *
 273  * %-ENOMEM - Insufficient amount of memory available.
 274  */
 275 int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
 276 {
 277         struct nilfs_palloc_req req;
 278         int ret;
 279
 280         req.pr_entry_nr = vblocknr;
 281         ret = nilfs_dat_prepare_entry(dat, &req, 0);
 282         if (ret == 0)
 283                 nilfs_dat_commit_entry(dat, &req);
 284         return ret;
 285 }
 286
 287 /**
 288  * nilfs_dat_freev - free virtual block numbers
 289  * @dat: DAT file inode
 290  * @vblocknrs: array of virtual block numbers
 291  * @nitems: number of virtual block numbers
 292  *
 293  * Description: nilfs_dat_freev() frees the virtual block numbers specified by
 294  * @vblocknrs and @nitems.
 295  *
 296  * Return Value: On success, 0 is returned. On error, one of the following
 297  * negative error codes is returned.
 298  *
 299  * %-EIO - I/O error.
 300  *
 301  * %-ENOMEM - Insufficient amount of memory available.
 302  *
 303  * %-ENOENT - The virtual block number have not been allocated.
 304  */
 305 int nilfs_dat_freev(struct inode *dat, __u64 *vblocknrs, size_t nitems)
 306 {
 307         return nilfs_palloc_freev(dat, vblocknrs, nitems);
 308 }
 309
 310 /**
 311  * nilfs_dat_move - change a block number
 312  * @dat: DAT file inode
 313  * @vblocknr: virtual block number
 314  * @blocknr: block number
 315  *
 316  * Description: nilfs_dat_move() changes the block number associated with
 317  * @vblocknr to @blocknr.
 318  *
 319  * Return Value: On success, 0 is returned. On error, one of the following
 320  * negative error codes is returned.
 321  *
 322  * %-EIO - I/O error.
 323  *
 324  * %-ENOMEM - Insufficient amount of memory available.
 325  */
 326 int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
 327 {
 328         struct buffer_head *entry_bh;
 329         struct nilfs_dat_entry *entry;
 330         void *kaddr;
 331         int ret;
 332
 333         ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
 334         if (ret < 0)
 335                 return ret;
 336
 337         /*
 338          * The given disk block number (blocknr) is not yet written to
 339          * the device at this point.
 340          *
 341          * To prevent nilfs_dat_translate() from returning the
 342          * uncommitted block number, this makes a copy of the entry
 343          * buffer and redirects nilfs_dat_translate() to the copy.
 344          */
 345         if (!buffer_nilfs_redirected(entry_bh)) {
 346                 ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
 347                 if (ret) {
 348                         brelse(entry_bh);
 349                         return ret;
 350                 }
 351         }
 352
 353         kaddr = kmap_atomic(entry_bh->b_page);
 354         entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
 355         if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
 356                 printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
 357                        (unsigned long long)vblocknr,
 358                        (unsigned long long)le64_to_cpu(entry->de_start),
 359                        (unsigned long long)le64_to_cpu(entry->de_end));
 360                 kunmap_atomic(kaddr);
 361                 brelse(entry_bh);
 362                 return -EINVAL;
 363         }
 364         WARN_ON(blocknr == 0);
 365         entry->de_blocknr = cpu_to_le64(blocknr);
 366         kunmap_atomic(kaddr);
 367
 368         mark_buffer_dirty(entry_bh);
 369         nilfs_mdt_mark_dirty(dat);
 370
 371         brelse(entry_bh);
 372
 373         return 0;
 374 }
 375
 376 /**
 377  * nilfs_dat_translate - translate a virtual block number to a block number
 378  * @dat: DAT file inode
 379  * @vblocknr: virtual block number
 380  * @blocknrp: pointer to a block number
 381  *
 382  * Description: nilfs_dat_translate() maps the virtual block number @vblocknr
 383  * to the corresponding block number.
 384  *
 385  * Return Value: On success, 0 is returned and the block number associated
 386  * with @vblocknr is stored in the place pointed by @blocknrp. On error, one
 387  * of the following negative error codes is returned.
 388  *
 389  * %-EIO - I/O error.
 390  *
 391  * %-ENOMEM - Insufficient amount of memory available.
 392  *
 393  * %-ENOENT - A block number associated with @vblocknr does not exist.
 394  */
 395 int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
 396 {
 397         struct buffer_head *entry_bh, *bh;
 398         struct nilfs_dat_entry *entry;
 399         sector_t blocknr;
 400         void *kaddr;
 401         int ret;
 402
 403         ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
 404         if (ret < 0)
 405                 return ret;
 406
 407         if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
 408                 bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
 409                 if (bh) {
 410                         WARN_ON(!buffer_uptodate(bh));
 411                         brelse(entry_bh);
 412                         entry_bh = bh;
 413                 }
 414         }
 415
 416         kaddr = kmap_atomic(entry_bh->b_page);
 417         entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
 418         blocknr = le64_to_cpu(entry->de_blocknr);
 419         if (blocknr == 0) {
 420                 ret = -ENOENT;
 421                 goto out;
 422         }
 423         *blocknrp = blocknr;
 424
 425  out:
 426         kunmap_atomic(kaddr);
 427         brelse(entry_bh);
 428         return ret;
 429 }
 430
 431 ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned visz,
 432                             size_t nvi)
 433 {
 434         struct buffer_head *entry_bh;
 435         struct nilfs_dat_entry *entry;
 436         struct nilfs_vinfo *vinfo = buf;
 437         __u64 first, last;
 438         void *kaddr;
 439         unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
 440         int i, j, n, ret;
 441
 442         for (i = 0; i < nvi; i += n) {
 443                 ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
 444                                                    0, &entry_bh);
 445                 if (ret < 0)
 446                         return ret;
 447                 kaddr = kmap_atomic(entry_bh->b_page);
 448                 /* last virtual block number in this block */
 449                 first = vinfo->vi_vblocknr;
 450                 do_div(first, entries_per_block);
 451                 first *= entries_per_block;
 452                 last = first + entries_per_block - 1;
 453                 for (j = i, n = 0;
 454                      j < nvi && vinfo->vi_vblocknr >= first &&
 455                              vinfo->vi_vblocknr <= last;
 456                      j++, n++, vinfo = (void *)vinfo + visz) {
 457                         entry = nilfs_palloc_block_get_entry(
 458                                 dat, vinfo->vi_vblocknr, entry_bh, kaddr);
 459                         vinfo->vi_start = le64_to_cpu(entry->de_start);
 460                         vinfo->vi_end = le64_to_cpu(entry->de_end);
 461                         vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
 462                 }
 463                 kunmap_atomic(kaddr);
 464                 brelse(entry_bh);
 465         }
 466
 467         return nvi;
 468 }
 469
 470 /**
 471  * nilfs_dat_read - read or get dat inode
 472  * @sb: super block instance
 473  * @entry_size: size of a dat entry
 474  * @raw_inode: on-disk dat inode
 475  * @inodep: buffer to store the inode
 476  */
 477 int nilfs_dat_read(struct super_block *sb, size_t entry_size,
 478                    struct nilfs_inode *raw_inode, struct inode **inodep)
 479 {
 480         static struct lock_class_key dat_lock_key;
 481         struct inode *dat;
 482         struct nilfs_dat_info *di;
 483         int err;
 484
 485         if (entry_size > sb->s_blocksize) {
 486                 printk(KERN_ERR
 487                        "NILFS: too large DAT entry size: %zu bytes.\n",
 488                        entry_size);
 489                 return -EINVAL;
 490         } else if (entry_size < NILFS_MIN_DAT_ENTRY_SIZE) {
 491                 printk(KERN_ERR
 492                        "NILFS: too small DAT entry size: %zu bytes.\n",
 493                        entry_size);
 494                 return -EINVAL;
 495         }
 496
 497         dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
 498         if (unlikely(!dat))
 499                 return -ENOMEM;
 500         if (!(dat->i_state & I_NEW))
 501                 goto out;
 502
 503         err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
 504         if (err)
 505                 goto failed;
 506
 507         err = nilfs_palloc_init_blockgroup(dat, entry_size);
 508         if (err)
 509                 goto failed;
 510
 511         di = NILFS_DAT_I(dat);
 512         lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
 513         nilfs_palloc_setup_cache(dat, &di->palloc_cache);
 514         nilfs_mdt_setup_shadow_map(dat, &di->shadow);
 515
 516         err = nilfs_read_inode_common(dat, raw_inode);
 517         if (err)
 518                 goto failed;
 519
 520         unlock_new_inode(dat);
 521  out:
 522         *inodep = dat;
 523         return 0;
 524  failed:
 525         iget_failed(dat);
 526         return err;
 527 }