fs/nilfs2/sufile.c

   1 /*
   2  * sufile.c - NILFS segment usage file.
   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  * Revised by Ryusuke Konishi.
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/fs.h>
  22 #include <linux/string.h>
  23 #include <linux/buffer_head.h>
  24 #include <linux/errno.h>
  25 #include "mdt.h"
  26 #include "sufile.h"
  27
  28 #include <trace/events/nilfs2.h>
  29
  30 /**
  31  * struct nilfs_sufile_info - on-memory private data of sufile
  32  * @mi: on-memory private data of metadata file
  33  * @ncleansegs: number of clean segments
  34  * @allocmin: lower limit of allocatable segment range
  35  * @allocmax: upper limit of allocatable segment range
  36  */
  37 struct nilfs_sufile_info {
  38         struct nilfs_mdt_info mi;
  39         unsigned long ncleansegs;/* number of clean segments */
  40         __u64 allocmin;         /* lower limit of allocatable segment range */
  41         __u64 allocmax;         /* upper limit of allocatable segment range */
  42 };
  43
  44 static inline struct nilfs_sufile_info *NILFS_SUI(struct inode *sufile)
  45 {
  46         return (struct nilfs_sufile_info *)NILFS_MDT(sufile);
  47 }
  48
  49 static inline unsigned long
  50 nilfs_sufile_segment_usages_per_block(const struct inode *sufile)
  51 {
  52         return NILFS_MDT(sufile)->mi_entries_per_block;
  53 }
  54
  55 static unsigned long
  56 nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum)
  57 {
  58         __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
  59
  60         do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  61         return (unsigned long)t;
  62 }
  63
  64 static unsigned long
  65 nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum)
  66 {
  67         __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
  68
  69         return do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  70 }
  71
  72 static unsigned long
  73 nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr,
  74                                      __u64 max)
  75 {
  76         return min_t(unsigned long,
  77                      nilfs_sufile_segment_usages_per_block(sufile) -
  78                      nilfs_sufile_get_offset(sufile, curr),
  79                      max - curr + 1);
  80 }
  81
  82 static struct nilfs_segment_usage *
  83 nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum,
  84                                      struct buffer_head *bh, void *kaddr)
  85 {
  86         return kaddr + bh_offset(bh) +
  87                 nilfs_sufile_get_offset(sufile, segnum) *
  88                 NILFS_MDT(sufile)->mi_entry_size;
  89 }
  90
  91 static inline int nilfs_sufile_get_header_block(struct inode *sufile,
  92                                                 struct buffer_head **bhp)
  93 {
  94         return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
  95 }
  96
  97 static inline int
  98 nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
  99                                      int create, struct buffer_head **bhp)
 100 {
 101         return nilfs_mdt_get_block(sufile,
 102                                    nilfs_sufile_get_blkoff(sufile, segnum),
 103                                    create, NULL, bhp);
 104 }
 105
 106 static int nilfs_sufile_delete_segment_usage_block(struct inode *sufile,
 107                                                    __u64 segnum)
 108 {
 109         return nilfs_mdt_delete_block(sufile,
 110                                       nilfs_sufile_get_blkoff(sufile, segnum));
 111 }
 112
 113 static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
 114                                      u64 ncleanadd, u64 ndirtyadd)
 115 {
 116         struct nilfs_sufile_header *header;
 117         void *kaddr;
 118
 119         kaddr = kmap_atomic(header_bh->b_page);
 120         header = kaddr + bh_offset(header_bh);
 121         le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
 122         le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
 123         kunmap_atomic(kaddr);
 124
 125         mark_buffer_dirty(header_bh);
 126 }
 127
 128 /**
 129  * nilfs_sufile_get_ncleansegs - return the number of clean segments
 130  * @sufile: inode of segment usage file
 131  */
 132 unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile)
 133 {
 134         return NILFS_SUI(sufile)->ncleansegs;
 135 }
 136
 137 /**
 138  * nilfs_sufile_updatev - modify multiple segment usages at a time
 139  * @sufile: inode of segment usage file
 140  * @segnumv: array of segment numbers
 141  * @nsegs: size of @segnumv array
 142  * @create: creation flag
 143  * @ndone: place to store number of modified segments on @segnumv
 144  * @dofunc: primitive operation for the update
 145  *
 146  * Description: nilfs_sufile_updatev() repeatedly calls @dofunc
 147  * against the given array of segments.  The @dofunc is called with
 148  * buffers of a header block and the sufile block in which the target
 149  * segment usage entry is contained.  If @ndone is given, the number
 150  * of successfully modified segments from the head is stored in the
 151  * place @ndone points to.
 152  *
 153  * Return Value: On success, zero is returned.  On error, one of the
 154  * following negative error codes is returned.
 155  *
 156  * %-EIO - I/O error.
 157  *
 158  * %-ENOMEM - Insufficient amount of memory available.
 159  *
 160  * %-ENOENT - Given segment usage is in hole block (may be returned if
 161  *            @create is zero)
 162  *
 163  * %-EINVAL - Invalid segment usage number
 164  */
 165 int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
 166                          int create, size_t *ndone,
 167                          void (*dofunc)(struct inode *, __u64,
 168                                         struct buffer_head *,
 169                                         struct buffer_head *))
 170 {
 171         struct buffer_head *header_bh, *bh;
 172         unsigned long blkoff, prev_blkoff;
 173         __u64 *seg;
 174         size_t nerr = 0, n = 0;
 175         int ret = 0;
 176
 177         if (unlikely(nsegs == 0))
 178                 goto out;
 179
 180         down_write(&NILFS_MDT(sufile)->mi_sem);
 181         for (seg = segnumv; seg < segnumv + nsegs; seg++) {
 182                 if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
 183                         nilfs_msg(sufile->i_sb, KERN_WARNING,
 184                                   "%s: invalid segment number: %llu",
 185                                   __func__, (unsigned long long)*seg);
 186                         nerr++;
 187                 }
 188         }
 189         if (nerr > 0) {
 190                 ret = -EINVAL;
 191                 goto out_sem;
 192         }
 193
 194         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 195         if (ret < 0)
 196                 goto out_sem;
 197
 198         seg = segnumv;
 199         blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 200         ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 201         if (ret < 0)
 202                 goto out_header;
 203
 204         for (;;) {
 205                 dofunc(sufile, *seg, header_bh, bh);
 206
 207                 if (++seg >= segnumv + nsegs)
 208                         break;
 209                 prev_blkoff = blkoff;
 210                 blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 211                 if (blkoff == prev_blkoff)
 212                         continue;
 213
 214                 /* get different block */
 215                 brelse(bh);
 216                 ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 217                 if (unlikely(ret < 0))
 218                         goto out_header;
 219         }
 220         brelse(bh);
 221
 222  out_header:
 223         n = seg - segnumv;
 224         brelse(header_bh);
 225  out_sem:
 226         up_write(&NILFS_MDT(sufile)->mi_sem);
 227  out:
 228         if (ndone)
 229                 *ndone = n;
 230         return ret;
 231 }
 232
 233 int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
 234                         void (*dofunc)(struct inode *, __u64,
 235                                        struct buffer_head *,
 236                                        struct buffer_head *))
 237 {
 238         struct buffer_head *header_bh, *bh;
 239         int ret;
 240
 241         if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
 242                 nilfs_msg(sufile->i_sb, KERN_WARNING,
 243                           "%s: invalid segment number: %llu",
 244                           __func__, (unsigned long long)segnum);
 245                 return -EINVAL;
 246         }
 247         down_write(&NILFS_MDT(sufile)->mi_sem);
 248
 249         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 250         if (ret < 0)
 251                 goto out_sem;
 252
 253         ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
 254         if (!ret) {
 255                 dofunc(sufile, segnum, header_bh, bh);
 256                 brelse(bh);
 257         }
 258         brelse(header_bh);
 259
 260  out_sem:
 261         up_write(&NILFS_MDT(sufile)->mi_sem);
 262         return ret;
 263 }
 264
 265 /**
 266  * nilfs_sufile_set_alloc_range - limit range of segment to be allocated
 267  * @sufile: inode of segment usage file
 268  * @start: minimum segment number of allocatable region (inclusive)
 269  * @end: maximum segment number of allocatable region (inclusive)
 270  *
 271  * Return Value: On success, 0 is returned.  On error, one of the
 272  * following negative error codes is returned.
 273  *
 274  * %-ERANGE - invalid segment region
 275  */
 276 int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
 277 {
 278         struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 279         __u64 nsegs;
 280         int ret = -ERANGE;
 281
 282         down_write(&NILFS_MDT(sufile)->mi_sem);
 283         nsegs = nilfs_sufile_get_nsegments(sufile);
 284
 285         if (start <= end && end < nsegs) {
 286                 sui->allocmin = start;
 287                 sui->allocmax = end;
 288                 ret = 0;
 289         }
 290         up_write(&NILFS_MDT(sufile)->mi_sem);
 291         return ret;
 292 }
 293
 294 /**
 295  * nilfs_sufile_alloc - allocate a segment
 296  * @sufile: inode of segment usage file
 297  * @segnump: pointer to segment number
 298  *
 299  * Description: nilfs_sufile_alloc() allocates a clean segment.
 300  *
 301  * Return Value: On success, 0 is returned and the segment number of the
 302  * allocated segment is stored in the place pointed by @segnump. On error, one
 303  * of the following negative error codes is returned.
 304  *
 305  * %-EIO - I/O error.
 306  *
 307  * %-ENOMEM - Insufficient amount of memory available.
 308  *
 309  * %-ENOSPC - No clean segment left.
 310  */
 311 int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 312 {
 313         struct buffer_head *header_bh, *su_bh;
 314         struct nilfs_sufile_header *header;
 315         struct nilfs_segment_usage *su;
 316         struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 317         size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 318         __u64 segnum, maxsegnum, last_alloc;
 319         void *kaddr;
 320         unsigned long nsegments, nsus, cnt;
 321         int ret, j;
 322
 323         down_write(&NILFS_MDT(sufile)->mi_sem);
 324
 325         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 326         if (ret < 0)
 327                 goto out_sem;
 328         kaddr = kmap_atomic(header_bh->b_page);
 329         header = kaddr + bh_offset(header_bh);
 330         last_alloc = le64_to_cpu(header->sh_last_alloc);
 331         kunmap_atomic(kaddr);
 332
 333         nsegments = nilfs_sufile_get_nsegments(sufile);
 334         maxsegnum = sui->allocmax;
 335         segnum = last_alloc + 1;
 336         if (segnum < sui->allocmin || segnum > sui->allocmax)
 337                 segnum = sui->allocmin;
 338
 339         for (cnt = 0; cnt < nsegments; cnt += nsus) {
 340                 if (segnum > maxsegnum) {
 341                         if (cnt < sui->allocmax - sui->allocmin + 1) {
 342                                 /*
 343                                  * wrap around in the limited region.
 344                                  * if allocation started from
 345                                  * sui->allocmin, this never happens.
 346                                  */
 347                                 segnum = sui->allocmin;
 348                                 maxsegnum = last_alloc;
 349                         } else if (segnum > sui->allocmin &&
 350                                    sui->allocmax + 1 < nsegments) {
 351                                 segnum = sui->allocmax + 1;
 352                                 maxsegnum = nsegments - 1;
 353                         } else if (sui->allocmin > 0)  {
 354                                 segnum = 0;
 355                                 maxsegnum = sui->allocmin - 1;
 356                         } else {
 357                                 break; /* never happens */
 358                         }
 359                 }
 360                 trace_nilfs2_segment_usage_check(sufile, segnum, cnt);
 361                 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
 362                                                            &su_bh);
 363                 if (ret < 0)
 364                         goto out_header;
 365                 kaddr = kmap_atomic(su_bh->b_page);
 366                 su = nilfs_sufile_block_get_segment_usage(
 367                         sufile, segnum, su_bh, kaddr);
 368
 369                 nsus = nilfs_sufile_segment_usages_in_block(
 370                         sufile, segnum, maxsegnum);
 371                 for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
 372                         if (!nilfs_segment_usage_clean(su))
 373                                 continue;
 374                         /* found a clean segment */
 375                         nilfs_segment_usage_set_dirty(su);
 376                         kunmap_atomic(kaddr);
 377
 378                         kaddr = kmap_atomic(header_bh->b_page);
 379                         header = kaddr + bh_offset(header_bh);
 380                         le64_add_cpu(&header->sh_ncleansegs, -1);
 381                         le64_add_cpu(&header->sh_ndirtysegs, 1);
 382                         header->sh_last_alloc = cpu_to_le64(segnum);
 383                         kunmap_atomic(kaddr);
 384
 385                         sui->ncleansegs--;
 386                         mark_buffer_dirty(header_bh);
 387                         mark_buffer_dirty(su_bh);
 388                         nilfs_mdt_mark_dirty(sufile);
 389                         brelse(su_bh);
 390                         *segnump = segnum;
 391
 392                         trace_nilfs2_segment_usage_allocated(sufile, segnum);
 393
 394                         goto out_header;
 395                 }
 396
 397                 kunmap_atomic(kaddr);
 398                 brelse(su_bh);
 399         }
 400
 401         /* no segments left */
 402         ret = -ENOSPC;
 403
 404  out_header:
 405         brelse(header_bh);
 406
 407  out_sem:
 408         up_write(&NILFS_MDT(sufile)->mi_sem);
 409         return ret;
 410 }
 411
 412 void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
 413                                  struct buffer_head *header_bh,
 414                                  struct buffer_head *su_bh)
 415 {
 416         struct nilfs_segment_usage *su;
 417         void *kaddr;
 418
 419         kaddr = kmap_atomic(su_bh->b_page);
 420         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 421         if (unlikely(!nilfs_segment_usage_clean(su))) {
 422                 nilfs_msg(sufile->i_sb, KERN_WARNING,
 423                           "%s: segment %llu must be clean", __func__,
 424                           (unsigned long long)segnum);
 425                 kunmap_atomic(kaddr);
 426                 return;
 427         }
 428         nilfs_segment_usage_set_dirty(su);
 429         kunmap_atomic(kaddr);
 430
 431         nilfs_sufile_mod_counter(header_bh, -1, 1);
 432         NILFS_SUI(sufile)->ncleansegs--;
 433
 434         mark_buffer_dirty(su_bh);
 435         nilfs_mdt_mark_dirty(sufile);
 436 }
 437
 438 void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
 439                            struct buffer_head *header_bh,
 440                            struct buffer_head *su_bh)
 441 {
 442         struct nilfs_segment_usage *su;
 443         void *kaddr;
 444         int clean, dirty;
 445
 446         kaddr = kmap_atomic(su_bh->b_page);
 447         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 448         if (su->su_flags == cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY)) &&
 449             su->su_nblocks == cpu_to_le32(0)) {
 450                 kunmap_atomic(kaddr);
 451                 return;
 452         }
 453         clean = nilfs_segment_usage_clean(su);
 454         dirty = nilfs_segment_usage_dirty(su);
 455
 456         /* make the segment garbage */
 457         su->su_lastmod = cpu_to_le64(0);
 458         su->su_nblocks = cpu_to_le32(0);
 459         su->su_flags = cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY));
 460         kunmap_atomic(kaddr);
 461
 462         nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
 463         NILFS_SUI(sufile)->ncleansegs -= clean;
 464
 465         mark_buffer_dirty(su_bh);
 466         nilfs_mdt_mark_dirty(sufile);
 467 }
 468
 469 void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
 470                           struct buffer_head *header_bh,
 471                           struct buffer_head *su_bh)
 472 {
 473         struct nilfs_segment_usage *su;
 474         void *kaddr;
 475         int sudirty;
 476
 477         kaddr = kmap_atomic(su_bh->b_page);
 478         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 479         if (nilfs_segment_usage_clean(su)) {
 480                 nilfs_msg(sufile->i_sb, KERN_WARNING,
 481                           "%s: segment %llu is already clean",
 482                           __func__, (unsigned long long)segnum);
 483                 kunmap_atomic(kaddr);
 484                 return;
 485         }
 486         WARN_ON(nilfs_segment_usage_error(su));
 487         WARN_ON(!nilfs_segment_usage_dirty(su));
 488
 489         sudirty = nilfs_segment_usage_dirty(su);
 490         nilfs_segment_usage_set_clean(su);
 491         kunmap_atomic(kaddr);
 492         mark_buffer_dirty(su_bh);
 493
 494         nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
 495         NILFS_SUI(sufile)->ncleansegs++;
 496
 497         nilfs_mdt_mark_dirty(sufile);
 498
 499         trace_nilfs2_segment_usage_freed(sufile, segnum);
 500 }
 501
 502 /**
 503  * nilfs_sufile_mark_dirty - mark the buffer having a segment usage dirty
 504  * @sufile: inode of segment usage file
 505  * @segnum: segment number
 506  */
 507 int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
 508 {
 509         struct buffer_head *bh;
 510         void *kaddr;
 511         struct nilfs_segment_usage *su;
 512         int ret;
 513
 514         down_write(&NILFS_MDT(sufile)->mi_sem);
 515         ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 516         if (!ret) {
 517                 mark_buffer_dirty(bh);
 518                 nilfs_mdt_mark_dirty(sufile);
 519                 kaddr = kmap_atomic(bh->b_page);
 520                 su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
 521                 nilfs_segment_usage_set_dirty(su);
 522                 kunmap_atomic(kaddr);
 523                 brelse(bh);
 524         }
 525         up_write(&NILFS_MDT(sufile)->mi_sem);
 526         return ret;
 527 }
 528
 529 /**
 530  * nilfs_sufile_set_segment_usage - set usage of a segment
 531  * @sufile: inode of segment usage file
 532  * @segnum: segment number
 533  * @nblocks: number of live blocks in the segment
 534  * @modtime: modification time (option)
 535  */
 536 int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
 537                                    unsigned long nblocks, time_t modtime)
 538 {
 539         struct buffer_head *bh;
 540         struct nilfs_segment_usage *su;
 541         void *kaddr;
 542         int ret;
 543
 544         down_write(&NILFS_MDT(sufile)->mi_sem);
 545         ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 546         if (ret < 0)
 547                 goto out_sem;
 548
 549         kaddr = kmap_atomic(bh->b_page);
 550         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
 551         WARN_ON(nilfs_segment_usage_error(su));
 552         if (modtime)
 553                 su->su_lastmod = cpu_to_le64(modtime);
 554         su->su_nblocks = cpu_to_le32(nblocks);
 555         kunmap_atomic(kaddr);
 556
 557         mark_buffer_dirty(bh);
 558         nilfs_mdt_mark_dirty(sufile);
 559         brelse(bh);
 560
 561  out_sem:
 562         up_write(&NILFS_MDT(sufile)->mi_sem);
 563         return ret;
 564 }
 565
 566 /**
 567  * nilfs_sufile_get_stat - get segment usage statistics
 568  * @sufile: inode of segment usage file
 569  * @stat: pointer to a structure of segment usage statistics
 570  *
 571  * Description: nilfs_sufile_get_stat() returns information about segment
 572  * usage.
 573  *
 574  * Return Value: On success, 0 is returned, and segment usage information is
 575  * stored in the place pointed by @stat. On error, one of the following
 576  * negative error codes is returned.
 577  *
 578  * %-EIO - I/O error.
 579  *
 580  * %-ENOMEM - Insufficient amount of memory available.
 581  */
 582 int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 583 {
 584         struct buffer_head *header_bh;
 585         struct nilfs_sufile_header *header;
 586         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 587         void *kaddr;
 588         int ret;
 589
 590         down_read(&NILFS_MDT(sufile)->mi_sem);
 591
 592         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 593         if (ret < 0)
 594                 goto out_sem;
 595
 596         kaddr = kmap_atomic(header_bh->b_page);
 597         header = kaddr + bh_offset(header_bh);
 598         sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
 599         sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
 600         sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
 601         sustat->ss_ctime = nilfs->ns_ctime;
 602         sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
 603         spin_lock(&nilfs->ns_last_segment_lock);
 604         sustat->ss_prot_seq = nilfs->ns_prot_seq;
 605         spin_unlock(&nilfs->ns_last_segment_lock);
 606         kunmap_atomic(kaddr);
 607         brelse(header_bh);
 608
 609  out_sem:
 610         up_read(&NILFS_MDT(sufile)->mi_sem);
 611         return ret;
 612 }
 613
 614 void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
 615                                struct buffer_head *header_bh,
 616                                struct buffer_head *su_bh)
 617 {
 618         struct nilfs_segment_usage *su;
 619         void *kaddr;
 620         int suclean;
 621
 622         kaddr = kmap_atomic(su_bh->b_page);
 623         su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 624         if (nilfs_segment_usage_error(su)) {
 625                 kunmap_atomic(kaddr);
 626                 return;
 627         }
 628         suclean = nilfs_segment_usage_clean(su);
 629         nilfs_segment_usage_set_error(su);
 630         kunmap_atomic(kaddr);
 631
 632         if (suclean) {
 633                 nilfs_sufile_mod_counter(header_bh, -1, 0);
 634                 NILFS_SUI(sufile)->ncleansegs--;
 635         }
 636         mark_buffer_dirty(su_bh);
 637         nilfs_mdt_mark_dirty(sufile);
 638 }
 639
 640 /**
 641   * nilfs_sufile_truncate_range - truncate range of segment array
 642   * @sufile: inode of segment usage file
 643   * @start: start segment number (inclusive)
 644   * @end: end segment number (inclusive)
 645   *
 646   * Return Value: On success, 0 is returned.  On error, one of the
 647   * following negative error codes is returned.
 648   *
 649   * %-EIO - I/O error.
 650   *
 651   * %-ENOMEM - Insufficient amount of memory available.
 652   *
 653   * %-EINVAL - Invalid number of segments specified
 654   *
 655   * %-EBUSY - Dirty or active segments are present in the range
 656   */
 657 static int nilfs_sufile_truncate_range(struct inode *sufile,
 658                                        __u64 start, __u64 end)
 659 {
 660         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 661         struct buffer_head *header_bh;
 662         struct buffer_head *su_bh;
 663         struct nilfs_segment_usage *su, *su2;
 664         size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 665         unsigned long segusages_per_block;
 666         unsigned long nsegs, ncleaned;
 667         __u64 segnum;
 668         void *kaddr;
 669         ssize_t n, nc;
 670         int ret;
 671         int j;
 672
 673         nsegs = nilfs_sufile_get_nsegments(sufile);
 674
 675         ret = -EINVAL;
 676         if (start > end || start >= nsegs)
 677                 goto out;
 678
 679         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 680         if (ret < 0)
 681                 goto out;
 682
 683         segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 684         ncleaned = 0;
 685
 686         for (segnum = start; segnum <= end; segnum += n) {
 687                 n = min_t(unsigned long,
 688                           segusages_per_block -
 689                                   nilfs_sufile_get_offset(sufile, segnum),
 690                           end - segnum + 1);
 691                 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 692                                                            &su_bh);
 693                 if (ret < 0) {
 694                         if (ret != -ENOENT)
 695                                 goto out_header;
 696                         /* hole */
 697                         continue;
 698                 }
 699                 kaddr = kmap_atomic(su_bh->b_page);
 700                 su = nilfs_sufile_block_get_segment_usage(
 701                         sufile, segnum, su_bh, kaddr);
 702                 su2 = su;
 703                 for (j = 0; j < n; j++, su = (void *)su + susz) {
 704                         if ((le32_to_cpu(su->su_flags) &
 705                              ~BIT(NILFS_SEGMENT_USAGE_ERROR)) ||
 706                             nilfs_segment_is_active(nilfs, segnum + j)) {
 707                                 ret = -EBUSY;
 708                                 kunmap_atomic(kaddr);
 709                                 brelse(su_bh);
 710                                 goto out_header;
 711                         }
 712                 }
 713                 nc = 0;
 714                 for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
 715                         if (nilfs_segment_usage_error(su)) {
 716                                 nilfs_segment_usage_set_clean(su);
 717                                 nc++;
 718                         }
 719                 }
 720                 kunmap_atomic(kaddr);
 721                 if (nc > 0) {
 722                         mark_buffer_dirty(su_bh);
 723                         ncleaned += nc;
 724                 }
 725                 brelse(su_bh);
 726
 727                 if (n == segusages_per_block) {
 728                         /* make hole */
 729                         nilfs_sufile_delete_segment_usage_block(sufile, segnum);
 730                 }
 731         }
 732         ret = 0;
 733
 734 out_header:
 735         if (ncleaned > 0) {
 736                 NILFS_SUI(sufile)->ncleansegs += ncleaned;
 737                 nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
 738                 nilfs_mdt_mark_dirty(sufile);
 739         }
 740         brelse(header_bh);
 741 out:
 742         return ret;
 743 }
 744
 745 /**
 746  * nilfs_sufile_resize - resize segment array
 747  * @sufile: inode of segment usage file
 748  * @newnsegs: new number of segments
 749  *
 750  * Return Value: On success, 0 is returned.  On error, one of the
 751  * following negative error codes is returned.
 752  *
 753  * %-EIO - I/O error.
 754  *
 755  * %-ENOMEM - Insufficient amount of memory available.
 756  *
 757  * %-ENOSPC - Enough free space is not left for shrinking
 758  *
 759  * %-EBUSY - Dirty or active segments exist in the region to be truncated
 760  */
 761 int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
 762 {
 763         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 764         struct buffer_head *header_bh;
 765         struct nilfs_sufile_header *header;
 766         struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 767         void *kaddr;
 768         unsigned long nsegs, nrsvsegs;
 769         int ret = 0;
 770
 771         down_write(&NILFS_MDT(sufile)->mi_sem);
 772
 773         nsegs = nilfs_sufile_get_nsegments(sufile);
 774         if (nsegs == newnsegs)
 775                 goto out;
 776
 777         ret = -ENOSPC;
 778         nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
 779         if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
 780                 goto out;
 781
 782         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 783         if (ret < 0)
 784                 goto out;
 785
 786         if (newnsegs > nsegs) {
 787                 sui->ncleansegs += newnsegs - nsegs;
 788         } else /* newnsegs < nsegs */ {
 789                 ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
 790                 if (ret < 0)
 791                         goto out_header;
 792
 793                 sui->ncleansegs -= nsegs - newnsegs;
 794
 795                 /*
 796                  * If the sufile is successfully truncated, immediately adjust
 797                  * the segment allocation space while locking the semaphore
 798                  * "mi_sem" so that nilfs_sufile_alloc() never allocates
 799                  * segments in the truncated space.
 800                  */
 801                 sui->allocmax = newnsegs - 1;
 802                 sui->allocmin = 0;
 803         }
 804
 805         kaddr = kmap_atomic(header_bh->b_page);
 806         header = kaddr + bh_offset(header_bh);
 807         header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
 808         kunmap_atomic(kaddr);
 809
 810         mark_buffer_dirty(header_bh);
 811         nilfs_mdt_mark_dirty(sufile);
 812         nilfs_set_nsegments(nilfs, newnsegs);
 813
 814 out_header:
 815         brelse(header_bh);
 816 out:
 817         up_write(&NILFS_MDT(sufile)->mi_sem);
 818         return ret;
 819 }
 820
 821 /**
 822  * nilfs_sufile_get_suinfo -
 823  * @sufile: inode of segment usage file
 824  * @segnum: segment number to start looking
 825  * @buf: array of suinfo
 826  * @sisz: byte size of suinfo
 827  * @nsi: size of suinfo array
 828  *
 829  * Description:
 830  *
 831  * Return Value: On success, 0 is returned and .... On error, one of the
 832  * following negative error codes is returned.
 833  *
 834  * %-EIO - I/O error.
 835  *
 836  * %-ENOMEM - Insufficient amount of memory available.
 837  */
 838 ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
 839                                 unsigned int sisz, size_t nsi)
 840 {
 841         struct buffer_head *su_bh;
 842         struct nilfs_segment_usage *su;
 843         struct nilfs_suinfo *si = buf;
 844         size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 845         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 846         void *kaddr;
 847         unsigned long nsegs, segusages_per_block;
 848         ssize_t n;
 849         int ret, i, j;
 850
 851         down_read(&NILFS_MDT(sufile)->mi_sem);
 852
 853         segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 854         nsegs = min_t(unsigned long,
 855                       nilfs_sufile_get_nsegments(sufile) - segnum,
 856                       nsi);
 857         for (i = 0; i < nsegs; i += n, segnum += n) {
 858                 n = min_t(unsigned long,
 859                           segusages_per_block -
 860                                   nilfs_sufile_get_offset(sufile, segnum),
 861                           nsegs - i);
 862                 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 863                                                            &su_bh);
 864                 if (ret < 0) {
 865                         if (ret != -ENOENT)
 866                                 goto out;
 867                         /* hole */
 868                         memset(si, 0, sisz * n);
 869                         si = (void *)si + sisz * n;
 870                         continue;
 871                 }
 872
 873                 kaddr = kmap_atomic(su_bh->b_page);
 874                 su = nilfs_sufile_block_get_segment_usage(
 875                         sufile, segnum, su_bh, kaddr);
 876                 for (j = 0; j < n;
 877                      j++, su = (void *)su + susz, si = (void *)si + sisz) {
 878                         si->sui_lastmod = le64_to_cpu(su->su_lastmod);
 879                         si->sui_nblocks = le32_to_cpu(su->su_nblocks);
 880                         si->sui_flags = le32_to_cpu(su->su_flags) &
 881                                 ~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 882                         if (nilfs_segment_is_active(nilfs, segnum + j))
 883                                 si->sui_flags |=
 884                                         BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 885                 }
 886                 kunmap_atomic(kaddr);
 887                 brelse(su_bh);
 888         }
 889         ret = nsegs;
 890
 891  out:
 892         up_read(&NILFS_MDT(sufile)->mi_sem);
 893         return ret;
 894 }
 895
 896 /**
 897  * nilfs_sufile_set_suinfo - sets segment usage info
 898  * @sufile: inode of segment usage file
 899  * @buf: array of suinfo_update
 900  * @supsz: byte size of suinfo_update
 901  * @nsup: size of suinfo_update array
 902  *
 903  * Description: Takes an array of nilfs_suinfo_update structs and updates
 904  * segment usage accordingly. Only the fields indicated by the sup_flags
 905  * are updated.
 906  *
 907  * Return Value: On success, 0 is returned. On error, one of the
 908  * following negative error codes is returned.
 909  *
 910  * %-EIO - I/O error.
 911  *
 912  * %-ENOMEM - Insufficient amount of memory available.
 913  *
 914  * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
 915  */
 916 ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
 917                                 unsigned int supsz, size_t nsup)
 918 {
 919         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 920         struct buffer_head *header_bh, *bh;
 921         struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
 922         struct nilfs_segment_usage *su;
 923         void *kaddr;
 924         unsigned long blkoff, prev_blkoff;
 925         int cleansi, cleansu, dirtysi, dirtysu;
 926         long ncleaned = 0, ndirtied = 0;
 927         int ret = 0;
 928
 929         if (unlikely(nsup == 0))
 930                 return ret;
 931
 932         for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
 933                 if (sup->sup_segnum >= nilfs->ns_nsegments
 934                         || (sup->sup_flags &
 935                                 (~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
 936                         || (nilfs_suinfo_update_nblocks(sup) &&
 937                                 sup->sup_sui.sui_nblocks >
 938                                 nilfs->ns_blocks_per_segment))
 939                         return -EINVAL;
 940         }
 941
 942         down_write(&NILFS_MDT(sufile)->mi_sem);
 943
 944         ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 945         if (ret < 0)
 946                 goto out_sem;
 947
 948         sup = buf;
 949         blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 950         ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 951         if (ret < 0)
 952                 goto out_header;
 953
 954         for (;;) {
 955                 kaddr = kmap_atomic(bh->b_page);
 956                 su = nilfs_sufile_block_get_segment_usage(
 957                         sufile, sup->sup_segnum, bh, kaddr);
 958
 959                 if (nilfs_suinfo_update_lastmod(sup))
 960                         su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
 961
 962                 if (nilfs_suinfo_update_nblocks(sup))
 963                         su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
 964
 965                 if (nilfs_suinfo_update_flags(sup)) {
 966                         /*
 967                          * Active flag is a virtual flag projected by running
 968                          * nilfs kernel code - drop it not to write it to
 969                          * disk.
 970                          */
 971                         sup->sup_sui.sui_flags &=
 972                                         ~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 973
 974                         cleansi = nilfs_suinfo_clean(&sup->sup_sui);
 975                         cleansu = nilfs_segment_usage_clean(su);
 976                         dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
 977                         dirtysu = nilfs_segment_usage_dirty(su);
 978
 979                         if (cleansi && !cleansu)
 980                                 ++ncleaned;
 981                         else if (!cleansi && cleansu)
 982                                 --ncleaned;
 983
 984                         if (dirtysi && !dirtysu)
 985                                 ++ndirtied;
 986                         else if (!dirtysi && dirtysu)
 987                                 --ndirtied;
 988
 989                         su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
 990                 }
 991
 992                 kunmap_atomic(kaddr);
 993
 994                 sup = (void *)sup + supsz;
 995                 if (sup >= supend)
 996                         break;
 997
 998                 prev_blkoff = blkoff;
 999                 blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
1000                 if (blkoff == prev_blkoff)
1001                         continue;
1002
1003                 /* get different block */
1004                 mark_buffer_dirty(bh);
1005                 put_bh(bh);
1006                 ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
1007                 if (unlikely(ret < 0))
1008                         goto out_mark;
1009         }
1010         mark_buffer_dirty(bh);
1011         put_bh(bh);
1012
1013  out_mark:
1014         if (ncleaned || ndirtied) {
1015                 nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
1016                                 (u64)ndirtied);
1017                 NILFS_SUI(sufile)->ncleansegs += ncleaned;
1018         }
1019         nilfs_mdt_mark_dirty(sufile);
1020  out_header:
1021         put_bh(header_bh);
1022  out_sem:
1023         up_write(&NILFS_MDT(sufile)->mi_sem);
1024         return ret;
1025 }
1026
1027 /**
1028  * nilfs_sufile_trim_fs() - trim ioctl handle function
1029  * @sufile: inode of segment usage file
1030  * @range: fstrim_range structure
1031  *
1032  * start:       First Byte to trim
1033  * len:         number of Bytes to trim from start
1034  * minlen:      minimum extent length in Bytes
1035  *
1036  * Decription: nilfs_sufile_trim_fs goes through all segments containing bytes
1037  * from start to start+len. start is rounded up to the next block boundary
1038  * and start+len is rounded down. For each clean segment blkdev_issue_discard
1039  * function is invoked.
1040  *
1041  * Return Value: On success, 0 is returned or negative error code, otherwise.
1042  */
1043 int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range)
1044 {
1045         struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
1046         struct buffer_head *su_bh;
1047         struct nilfs_segment_usage *su;
1048         void *kaddr;
1049         size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size;
1050         sector_t seg_start, seg_end, start_block, end_block;
1051         sector_t start = 0, nblocks = 0;
1052         u64 segnum, segnum_end, minlen, len, max_blocks, ndiscarded = 0;
1053         int ret = 0;
1054         unsigned int sects_per_block;
1055
1056         sects_per_block = (1 << nilfs->ns_blocksize_bits) /
1057                         bdev_logical_block_size(nilfs->ns_bdev);
1058         len = range->len >> nilfs->ns_blocksize_bits;
1059         minlen = range->minlen >> nilfs->ns_blocksize_bits;
1060         max_blocks = ((u64)nilfs->ns_nsegments * nilfs->ns_blocks_per_segment);
1061
1062         if (!len || range->start >= max_blocks << nilfs->ns_blocksize_bits)
1063                 return -EINVAL;
1064
1065         start_block = (range->start + nilfs->ns_blocksize - 1) >>
1066                         nilfs->ns_blocksize_bits;
1067
1068         /*
1069          * range->len can be very large (actually, it is set to
1070          * ULLONG_MAX by default) - truncate upper end of the range
1071          * carefully so as not to overflow.
1072          */
1073         if (max_blocks - start_block < len)
1074                 end_block = max_blocks - 1;
1075         else
1076                 end_block = start_block + len - 1;
1077
1078         segnum = nilfs_get_segnum_of_block(nilfs, start_block);
1079         segnum_end = nilfs_get_segnum_of_block(nilfs, end_block);
1080
1081         down_read(&NILFS_MDT(sufile)->mi_sem);
1082
1083         while (segnum <= segnum_end) {
1084                 n = nilfs_sufile_segment_usages_in_block(sufile, segnum,
1085                                 segnum_end);
1086
1087                 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
1088                                                            &su_bh);
1089                 if (ret < 0) {
1090                         if (ret != -ENOENT)
1091                                 goto out_sem;
1092                         /* hole */
1093                         segnum += n;
1094                         continue;
1095                 }
1096
1097                 kaddr = kmap_atomic(su_bh->b_page);
1098                 su = nilfs_sufile_block_get_segment_usage(sufile, segnum,
1099                                 su_bh, kaddr);
1100                 for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) {
1101                         if (!nilfs_segment_usage_clean(su))
1102                                 continue;
1103
1104                         nilfs_get_segment_range(nilfs, segnum, &seg_start,
1105                                                 &seg_end);
1106
1107                         if (!nblocks) {
1108                                 /* start new extent */
1109                                 start = seg_start;
1110                                 nblocks = seg_end - seg_start + 1;
1111                                 continue;
1112                         }
1113
1114                         if (start + nblocks == seg_start) {
1115                                 /* add to previous extent */
1116                                 nblocks += seg_end - seg_start + 1;
1117                                 continue;
1118                         }
1119
1120                         /* discard previous extent */
1121                         if (start < start_block) {
1122                                 nblocks -= start_block - start;
1123                                 start = start_block;
1124                         }
1125
1126                         if (nblocks >= minlen) {
1127                                 kunmap_atomic(kaddr);
1128
1129                                 ret = blkdev_issue_discard(nilfs->ns_bdev,
1130                                                 start * sects_per_block,
1131                                                 nblocks * sects_per_block,
1132                                                 GFP_NOFS, 0);
1133                                 if (ret < 0) {
1134                                         put_bh(su_bh);
1135                                         goto out_sem;
1136                                 }
1137
1138                                 ndiscarded += nblocks;
1139                                 kaddr = kmap_atomic(su_bh->b_page);
1140                                 su = nilfs_sufile_block_get_segment_usage(
1141                                         sufile, segnum, su_bh, kaddr);
1142                         }
1143
1144                         /* start new extent */
1145                         start = seg_start;
1146                         nblocks = seg_end - seg_start + 1;
1147                 }
1148                 kunmap_atomic(kaddr);
1149                 put_bh(su_bh);
1150         }
1151
1152
1153         if (nblocks) {
1154                 /* discard last extent */
1155                 if (start < start_block) {
1156                         nblocks -= start_block - start;
1157                         start = start_block;
1158                 }
1159                 if (start + nblocks > end_block + 1)
1160                         nblocks = end_block - start + 1;
1161
1162                 if (nblocks >= minlen) {
1163                         ret = blkdev_issue_discard(nilfs->ns_bdev,
1164                                         start * sects_per_block,
1165                                         nblocks * sects_per_block,
1166                                         GFP_NOFS, 0);
1167                         if (!ret)
1168                                 ndiscarded += nblocks;
1169                 }
1170         }
1171
1172 out_sem:
1173         up_read(&NILFS_MDT(sufile)->mi_sem);
1174
1175         range->len = ndiscarded << nilfs->ns_blocksize_bits;
1176         return ret;
1177 }
1178
1179 /**
1180  * nilfs_sufile_read - read or get sufile inode
1181  * @sb: super block instance
1182  * @susize: size of a segment usage entry
1183  * @raw_inode: on-disk sufile inode
1184  * @inodep: buffer to store the inode
1185  */
1186 int nilfs_sufile_read(struct super_block *sb, size_t susize,
1187                       struct nilfs_inode *raw_inode, struct inode **inodep)
1188 {
1189         struct inode *sufile;
1190         struct nilfs_sufile_info *sui;
1191         struct buffer_head *header_bh;
1192         struct nilfs_sufile_header *header;
1193         void *kaddr;
1194         int err;
1195
1196         if (susize > sb->s_blocksize) {
1197                 nilfs_msg(sb, KERN_ERR,
1198                           "too large segment usage size: %zu bytes", susize);
1199                 return -EINVAL;
1200         } else if (susize < NILFS_MIN_SEGMENT_USAGE_SIZE) {
1201                 nilfs_msg(sb, KERN_ERR,
1202                           "too small segment usage size: %zu bytes", susize);
1203                 return -EINVAL;
1204         }
1205
1206         sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
1207         if (unlikely(!sufile))
1208                 return -ENOMEM;
1209         if (!(sufile->i_state & I_NEW))
1210                 goto out;
1211
1212         err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
1213         if (err)
1214                 goto failed;
1215
1216         nilfs_mdt_set_entry_size(sufile, susize,
1217                                  sizeof(struct nilfs_sufile_header));
1218
1219         err = nilfs_read_inode_common(sufile, raw_inode);
1220         if (err)
1221                 goto failed;
1222
1223         err = nilfs_sufile_get_header_block(sufile, &header_bh);
1224         if (err)
1225                 goto failed;
1226
1227         sui = NILFS_SUI(sufile);
1228         kaddr = kmap_atomic(header_bh->b_page);
1229         header = kaddr + bh_offset(header_bh);
1230         sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
1231         kunmap_atomic(kaddr);
1232         brelse(header_bh);
1233
1234         sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
1235         sui->allocmin = 0;
1236
1237         unlock_new_inode(sufile);
1238  out:
1239         *inodep = sufile;
1240         return 0;
1241  failed:
1242         iget_failed(sufile);
1243         return err;
1244 }