fs/jfs/super.c

   1 /*
   2  *   Copyright (C) International Business Machines Corp., 2000-2004
   3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
   4  *
   5  *   This program is free software;  you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  13  *   the GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program;  if not, write to the Free Software
  17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  */
  19
  20 #include <linux/fs.h>
  21 #include <linux/module.h>
  22 #include <linux/parser.h>
  23 #include <linux/completion.h>
  24 #include <linux/vfs.h>
  25 #include <linux/mount.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/kthread.h>
  28 #include <linux/posix_acl.h>
  29 #include <linux/buffer_head.h>
  30 #include <asm/uaccess.h>
  31 #include <linux/seq_file.h>
  32
  33 #include "jfs_incore.h"
  34 #include "jfs_filsys.h"
  35 #include "jfs_inode.h"
  36 #include "jfs_metapage.h"
  37 #include "jfs_superblock.h"
  38 #include "jfs_dmap.h"
  39 #include "jfs_imap.h"
  40 #include "jfs_acl.h"
  41 #include "jfs_debug.h"
  42
  43 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
  44 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
  45 MODULE_LICENSE("GPL");
  46
  47 static kmem_cache_t * jfs_inode_cachep;
  48
  49 static struct super_operations jfs_super_operations;
  50 static struct export_operations jfs_export_operations;
  51 static struct file_system_type jfs_fs_type;
  52
  53 #define MAX_COMMIT_THREADS 64
  54 static int commit_threads = 0;
  55 module_param(commit_threads, int, 0);
  56 MODULE_PARM_DESC(commit_threads, "Number of commit threads");
  57
  58 static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
  59 struct task_struct *jfsIOthread;
  60 struct task_struct *jfsSyncThread;
  61
  62 #ifdef CONFIG_JFS_DEBUG
  63 int jfsloglevel = JFS_LOGLEVEL_WARN;
  64 module_param(jfsloglevel, int, 0644);
  65 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
  66 #endif
  67
  68 static void jfs_handle_error(struct super_block *sb)
  69 {
  70         struct jfs_sb_info *sbi = JFS_SBI(sb);
  71
  72         if (sb->s_flags & MS_RDONLY)
  73                 return;
  74
  75         updateSuper(sb, FM_DIRTY);
  76
  77         if (sbi->flag & JFS_ERR_PANIC)
  78                 panic("JFS (device %s): panic forced after error\n",
  79                         sb->s_id);
  80         else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
  81                 jfs_err("ERROR: (device %s): remounting filesystem "
  82                         "as read-only\n",
  83                         sb->s_id);
  84                 sb->s_flags |= MS_RDONLY;
  85         }
  86
  87         /* nothing is done for continue beyond marking the superblock dirty */
  88 }
  89
  90 void jfs_error(struct super_block *sb, const char * function, ...)
  91 {
  92         static char error_buf[256];
  93         va_list args;
  94
  95         va_start(args, function);
  96         vsprintf(error_buf, function, args);
  97         va_end(args);
  98
  99         printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
 100
 101         jfs_handle_error(sb);
 102 }
 103
 104 static struct inode *jfs_alloc_inode(struct super_block *sb)
 105 {
 106         struct jfs_inode_info *jfs_inode;
 107
 108         jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
 109         if (!jfs_inode)
 110                 return NULL;
 111         return &jfs_inode->vfs_inode;
 112 }
 113
 114 static void jfs_destroy_inode(struct inode *inode)
 115 {
 116         struct jfs_inode_info *ji = JFS_IP(inode);
 117
 118         BUG_ON(!list_empty(&ji->anon_inode_list));
 119
 120         spin_lock_irq(&ji->ag_lock);
 121         if (ji->active_ag != -1) {
 122                 struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
 123                 atomic_dec(&bmap->db_active[ji->active_ag]);
 124                 ji->active_ag = -1;
 125         }
 126         spin_unlock_irq(&ji->ag_lock);
 127
 128 #ifdef CONFIG_JFS_POSIX_ACL
 129         if (ji->i_acl != JFS_ACL_NOT_CACHED) {
 130                 posix_acl_release(ji->i_acl);
 131                 ji->i_acl = JFS_ACL_NOT_CACHED;
 132         }
 133         if (ji->i_default_acl != JFS_ACL_NOT_CACHED) {
 134                 posix_acl_release(ji->i_default_acl);
 135                 ji->i_default_acl = JFS_ACL_NOT_CACHED;
 136         }
 137 #endif
 138
 139         kmem_cache_free(jfs_inode_cachep, ji);
 140 }
 141
 142 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 143 {
 144         struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
 145         s64 maxinodes;
 146         struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
 147
 148         jfs_info("In jfs_statfs");
 149         buf->f_type = JFS_SUPER_MAGIC;
 150         buf->f_bsize = sbi->bsize;
 151         buf->f_blocks = sbi->bmap->db_mapsize;
 152         buf->f_bfree = sbi->bmap->db_nfree;
 153         buf->f_bavail = sbi->bmap->db_nfree;
 154         /*
 155          * If we really return the number of allocated & free inodes, some
 156          * applications will fail because they won't see enough free inodes.
 157          * We'll try to calculate some guess as to how may inodes we can
 158          * really allocate
 159          *
 160          * buf->f_files = atomic_read(&imap->im_numinos);
 161          * buf->f_ffree = atomic_read(&imap->im_numfree);
 162          */
 163         maxinodes = min((s64) atomic_read(&imap->im_numinos) +
 164                         ((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
 165                          << L2INOSPEREXT), (s64) 0xffffffffLL);
 166         buf->f_files = maxinodes;
 167         buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
 168                                     atomic_read(&imap->im_numfree));
 169
 170         buf->f_namelen = JFS_NAME_MAX;
 171         return 0;
 172 }
 173
 174 static void jfs_put_super(struct super_block *sb)
 175 {
 176         struct jfs_sb_info *sbi = JFS_SBI(sb);
 177         int rc;
 178
 179         jfs_info("In jfs_put_super");
 180         rc = jfs_umount(sb);
 181         if (rc)
 182                 jfs_err("jfs_umount failed with return code %d", rc);
 183         if (sbi->nls_tab)
 184                 unload_nls(sbi->nls_tab);
 185         sbi->nls_tab = NULL;
 186
 187         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 188         iput(sbi->direct_inode);
 189         sbi->direct_inode = NULL;
 190
 191         kfree(sbi);
 192 }
 193
 194 enum {
 195         Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
 196         Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
 197         Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask,
 198         Opt_tagxid
 199 };
 200
 201 static match_table_t tokens = {
 202         {Opt_integrity, "integrity"},
 203         {Opt_nointegrity, "nointegrity"},
 204         {Opt_iocharset, "iocharset=%s"},
 205         {Opt_resize, "resize=%u"},
 206         {Opt_resize_nosize, "resize"},
 207         {Opt_errors, "errors=%s"},
 208         {Opt_tagxid, "tagxid"},
 209         {Opt_ignore, "noquota"},
 210         {Opt_ignore, "quota"},
 211         {Opt_usrquota, "usrquota"},
 212         {Opt_grpquota, "grpquota"},
 213         {Opt_uid, "uid=%u"},
 214         {Opt_gid, "gid=%u"},
 215         {Opt_umask, "umask=%u"},
 216         {Opt_err, NULL}
 217 };
 218
 219 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
 220                          int *flag)
 221 {
 222         void *nls_map = (void *)-1;     /* -1: no change;  NULL: none */
 223         char *p;
 224         struct jfs_sb_info *sbi = JFS_SBI(sb);
 225
 226         *newLVSize = 0;
 227
 228         if (!options)
 229                 return 1;
 230
 231         while ((p = strsep(&options, ",")) != NULL) {
 232                 substring_t args[MAX_OPT_ARGS];
 233                 int token;
 234                 if (!*p)
 235                         continue;
 236
 237                 token = match_token(p, tokens, args);
 238                 switch (token) {
 239                 case Opt_integrity:
 240                         *flag &= ~JFS_NOINTEGRITY;
 241                         break;
 242                 case Opt_nointegrity:
 243                         *flag |= JFS_NOINTEGRITY;
 244                         break;
 245                 case Opt_ignore:
 246                         /* Silently ignore the quota options */
 247                         /* Don't do anything ;-) */
 248                         break;
 249                 case Opt_iocharset:
 250                         if (nls_map && nls_map != (void *) -1)
 251                                 unload_nls(nls_map);
 252                         if (!strcmp(args[0].from, "none"))
 253                                 nls_map = NULL;
 254                         else {
 255                                 nls_map = load_nls(args[0].from);
 256                                 if (!nls_map) {
 257                                         printk(KERN_ERR
 258                                                "JFS: charset not found\n");
 259                                         goto cleanup;
 260                                 }
 261                         }
 262                         break;
 263                 case Opt_resize:
 264                 {
 265                         char *resize = args[0].from;
 266                         *newLVSize = simple_strtoull(resize, &resize, 0);
 267                         break;
 268                 }
 269                 case Opt_resize_nosize:
 270                 {
 271                         *newLVSize = sb->s_bdev->bd_inode->i_size >>
 272                                 sb->s_blocksize_bits;
 273                         if (*newLVSize == 0)
 274                                 printk(KERN_ERR
 275                                        "JFS: Cannot determine volume size\n");
 276                         break;
 277                 }
 278                 case Opt_errors:
 279                 {
 280                         char *errors = args[0].from;
 281                         if (!errors || !*errors)
 282                                 goto cleanup;
 283                         if (!strcmp(errors, "continue")) {
 284                                 *flag &= ~JFS_ERR_REMOUNT_RO;
 285                                 *flag &= ~JFS_ERR_PANIC;
 286                                 *flag |= JFS_ERR_CONTINUE;
 287                         } else if (!strcmp(errors, "remount-ro")) {
 288                                 *flag &= ~JFS_ERR_CONTINUE;
 289                                 *flag &= ~JFS_ERR_PANIC;
 290                                 *flag |= JFS_ERR_REMOUNT_RO;
 291                         } else if (!strcmp(errors, "panic")) {
 292                                 *flag &= ~JFS_ERR_CONTINUE;
 293                                 *flag &= ~JFS_ERR_REMOUNT_RO;
 294                                 *flag |= JFS_ERR_PANIC;
 295                         } else {
 296                                 printk(KERN_ERR
 297                                        "JFS: %s is an invalid error handler\n",
 298                                        errors);
 299                                 goto cleanup;
 300                         }
 301                         break;
 302                 }
 303
 304 #ifdef CONFIG_QUOTA
 305                 case Opt_quota:
 306                 case Opt_usrquota:
 307                         *flag |= JFS_USRQUOTA;
 308                         break;
 309                 case Opt_grpquota:
 310                         *flag |= JFS_GRPQUOTA;
 311                         break;
 312 #else
 313                 case Opt_usrquota:
 314                 case Opt_grpquota:
 315                 case Opt_quota:
 316                         printk(KERN_ERR
 317                                "JFS: quota operations not supported\n");
 318                         break;
 319 #endif
 320                 case Opt_uid:
 321                 {
 322                         char *uid = args[0].from;
 323                         sbi->uid = simple_strtoul(uid, &uid, 0);
 324                         break;
 325                 }
 326                 case Opt_gid:
 327                 {
 328                         char *gid = args[0].from;
 329                         sbi->gid = simple_strtoul(gid, &gid, 0);
 330                         break;
 331                 }
 332                 case Opt_umask:
 333                 {
 334                         char *umask = args[0].from;
 335                         sbi->umask = simple_strtoul(umask, &umask, 8);
 336                         if (sbi->umask & ~0777) {
 337                                 printk(KERN_ERR
 338                                        "JFS: Invalid value of umask\n");
 339                                 goto cleanup;
 340                         }
 341                         break;
 342                 }
 343 #ifndef CONFIG_TAGGING_NONE
 344                 case Opt_tagxid:
 345                         *flag |= JFS_TAGXID;
 346                         break;
 347 #endif
 348                 default:
 349                         printk("jfs: Unrecognized mount option \"%s\" "
 350                                         " or missing value\n", p);
 351                         goto cleanup;
 352                 }
 353         }
 354
 355         if (nls_map != (void *) -1) {
 356                 /* Discard old (if remount) */
 357                 if (sbi->nls_tab)
 358                         unload_nls(sbi->nls_tab);
 359                 sbi->nls_tab = nls_map;
 360         }
 361         return 1;
 362
 363 cleanup:
 364         if (nls_map && nls_map != (void *) -1)
 365                 unload_nls(nls_map);
 366         return 0;
 367 }
 368
 369 static int jfs_remount(struct super_block *sb, int *flags, char *data)
 370 {
 371         s64 newLVSize = 0;
 372         int rc = 0;
 373         int flag = JFS_SBI(sb)->flag;
 374
 375         if (!parse_options(data, sb, &newLVSize, &flag)) {
 376                 return -EINVAL;
 377         }
 378
 379         if ((flag & JFS_TAGXID) && !(sb->s_flags & MS_TAGXID)) {
 380                 printk(KERN_ERR "JFS: %s: tagxid not permitted on remount.\n",
 381                         sb->s_id);
 382                 return -EINVAL;
 383         }
 384
 385         if (newLVSize) {
 386                 if (sb->s_flags & MS_RDONLY) {
 387                         printk(KERN_ERR
 388                   "JFS: resize requires volume to be mounted read-write\n");
 389                         return -EROFS;
 390                 }
 391                 rc = jfs_extendfs(sb, newLVSize, 0);
 392                 if (rc)
 393                         return rc;
 394         }
 395
 396         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
 397                 /*
 398                  * Invalidate any previously read metadata.  fsck may have
 399                  * changed the on-disk data since we mounted r/o
 400                  */
 401                 truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
 402
 403                 JFS_SBI(sb)->flag = flag;
 404                 return jfs_mount_rw(sb, 1);
 405         }
 406         if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
 407                 rc = jfs_umount_rw(sb);
 408                 JFS_SBI(sb)->flag = flag;
 409                 return rc;
 410         }
 411         if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
 412                 if (!(sb->s_flags & MS_RDONLY)) {
 413                         rc = jfs_umount_rw(sb);
 414                         if (rc)
 415                                 return rc;
 416                         JFS_SBI(sb)->flag = flag;
 417                         return jfs_mount_rw(sb, 1);
 418                 }
 419         JFS_SBI(sb)->flag = flag;
 420
 421         return 0;
 422 }
 423
 424 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 425 {
 426         struct jfs_sb_info *sbi;
 427         struct inode *inode;
 428         int rc;
 429         s64 newLVSize = 0;
 430         int flag;
 431
 432         jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
 433
 434         if (!new_valid_dev(sb->s_bdev->bd_dev))
 435                 return -EOVERFLOW;
 436
 437         sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
 438         if (!sbi)
 439                 return -ENOSPC;
 440         sb->s_fs_info = sbi;
 441         sbi->sb = sb;
 442         sbi->uid = sbi->gid = sbi->umask = -1;
 443
 444         /* initialize the mount flag and determine the default error handler */
 445         flag = JFS_ERR_REMOUNT_RO;
 446
 447         if (!parse_options((char *) data, sb, &newLVSize, &flag)) {
 448                 kfree(sbi);
 449                 return -EINVAL;
 450         }
 451         sbi->flag = flag;
 452
 453 #ifdef CONFIG_JFS_POSIX_ACL
 454         sb->s_flags |= MS_POSIXACL;
 455 #endif
 456         /* map mount option tagxid */
 457         if (sbi->flag & JFS_TAGXID)
 458                 sb->s_flags |= MS_TAGXID;
 459
 460         if (newLVSize) {
 461                 printk(KERN_ERR "resize option for remount only\n");
 462                 return -EINVAL;
 463         }
 464
 465         /*
 466          * Initialize blocksize to 4K.
 467          */
 468         sb_set_blocksize(sb, PSIZE);
 469
 470         /*
 471          * Set method vectors.
 472          */
 473         sb->s_op = &jfs_super_operations;
 474         sb->s_export_op = &jfs_export_operations;
 475
 476         /*
 477          * Initialize direct-mapping inode/address-space
 478          */
 479         inode = new_inode(sb);
 480         if (inode == NULL)
 481                 goto out_kfree;
 482         inode->i_ino = 0;
 483         inode->i_nlink = 1;
 484         inode->i_size = sb->s_bdev->bd_inode->i_size;
 485         inode->i_mapping->a_ops = &jfs_metapage_aops;
 486         insert_inode_hash(inode);
 487         mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
 488
 489         sbi->direct_inode = inode;
 490
 491         rc = jfs_mount(sb);
 492         if (rc) {
 493                 if (!silent) {
 494                         jfs_err("jfs_mount failed w/return code = %d", rc);
 495                 }
 496                 goto out_mount_failed;
 497         }
 498         if (sb->s_flags & MS_RDONLY)
 499                 sbi->log = NULL;
 500         else {
 501                 rc = jfs_mount_rw(sb, 0);
 502                 if (rc) {
 503                         if (!silent) {
 504                                 jfs_err("jfs_mount_rw failed, return code = %d",
 505                                         rc);
 506                         }
 507                         goto out_no_rw;
 508                 }
 509         }
 510
 511         sb->s_magic = JFS_SUPER_MAGIC;
 512
 513         inode = iget(sb, ROOT_I);
 514         if (!inode || is_bad_inode(inode))
 515                 goto out_no_root;
 516         sb->s_root = d_alloc_root(inode);
 517         if (!sb->s_root)
 518                 goto out_no_root;
 519
 520         if (sbi->mntflag & JFS_OS2)
 521                 sb->s_root->d_op = &jfs_ci_dentry_operations;
 522
 523         /* logical blocks are represented by 40 bits in pxd_t, etc. */
 524         sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
 525 #if BITS_PER_LONG == 32
 526         /*
 527          * Page cache is indexed by long.
 528          * I would use MAX_LFS_FILESIZE, but it's only half as big
 529          */
 530         sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, sb->s_maxbytes);
 531 #endif
 532         sb->s_time_gran = 1;
 533         return 0;
 534
 535 out_no_root:
 536         jfs_err("jfs_read_super: get root inode failed");
 537         if (inode)
 538                 iput(inode);
 539
 540 out_no_rw:
 541         rc = jfs_umount(sb);
 542         if (rc) {
 543                 jfs_err("jfs_umount failed with return code %d", rc);
 544         }
 545 out_mount_failed:
 546         filemap_write_and_wait(sbi->direct_inode->i_mapping);
 547         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 548         make_bad_inode(sbi->direct_inode);
 549         iput(sbi->direct_inode);
 550         sbi->direct_inode = NULL;
 551 out_kfree:
 552         if (sbi->nls_tab)
 553                 unload_nls(sbi->nls_tab);
 554         kfree(sbi);
 555         return -EINVAL;
 556 }
 557
 558 static void jfs_write_super_lockfs(struct super_block *sb)
 559 {
 560         struct jfs_sb_info *sbi = JFS_SBI(sb);
 561         struct jfs_log *log = sbi->log;
 562
 563         if (!(sb->s_flags & MS_RDONLY)) {
 564                 txQuiesce(sb);
 565                 lmLogShutdown(log);
 566                 updateSuper(sb, FM_CLEAN);
 567         }
 568 }
 569
 570 static void jfs_unlockfs(struct super_block *sb)
 571 {
 572         struct jfs_sb_info *sbi = JFS_SBI(sb);
 573         struct jfs_log *log = sbi->log;
 574         int rc = 0;
 575
 576         if (!(sb->s_flags & MS_RDONLY)) {
 577                 updateSuper(sb, FM_MOUNT);
 578                 if ((rc = lmLogInit(log)))
 579                         jfs_err("jfs_unlock failed with return code %d", rc);
 580                 else
 581                         txResume(sb);
 582         }
 583 }
 584
 585 static int jfs_get_sb(struct file_system_type *fs_type,
 586         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 587 {
 588         return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
 589                            mnt);
 590 }
 591
 592 static int jfs_sync_fs(struct super_block *sb, int wait)
 593 {
 594         struct jfs_log *log = JFS_SBI(sb)->log;
 595
 596         /* log == NULL indicates read-only mount */
 597         if (log) {
 598                 jfs_flush_journal(log, wait);
 599                 jfs_syncpt(log, 0);
 600         }
 601
 602         return 0;
 603 }
 604
 605 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 606 {
 607         struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
 608
 609         if (sbi->uid != -1)
 610                 seq_printf(seq, ",uid=%d", sbi->uid);
 611         if (sbi->gid != -1)
 612                 seq_printf(seq, ",gid=%d", sbi->gid);
 613         if (sbi->umask != -1)
 614                 seq_printf(seq, ",umask=%03o", sbi->umask);
 615         if (sbi->flag & JFS_NOINTEGRITY)
 616                 seq_puts(seq, ",nointegrity");
 617
 618 #ifdef CONFIG_QUOTA
 619         if (sbi->flag & JFS_USRQUOTA)
 620                 seq_puts(seq, ",usrquota");
 621
 622         if (sbi->flag & JFS_GRPQUOTA)
 623                 seq_puts(seq, ",grpquota");
 624 #endif
 625
 626         return 0;
 627 }
 628
 629 #ifdef CONFIG_QUOTA
 630
 631 /* Read data from quotafile - avoid pagecache and such because we cannot afford
 632  * acquiring the locks... As quota files are never truncated and quota code
 633  * itself serializes the operations (and noone else should touch the files)
 634  * we don't have to be afraid of races */
 635 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
 636                               size_t len, loff_t off)
 637 {
 638         struct inode *inode = sb_dqopt(sb)->files[type];
 639         sector_t blk = off >> sb->s_blocksize_bits;
 640         int err = 0;
 641         int offset = off & (sb->s_blocksize - 1);
 642         int tocopy;
 643         size_t toread;
 644         struct buffer_head tmp_bh;
 645         struct buffer_head *bh;
 646         loff_t i_size = i_size_read(inode);
 647
 648         if (off > i_size)
 649                 return 0;
 650         if (off+len > i_size)
 651                 len = i_size-off;
 652         toread = len;
 653         while (toread > 0) {
 654                 tocopy = sb->s_blocksize - offset < toread ?
 655                                 sb->s_blocksize - offset : toread;
 656
 657                 tmp_bh.b_state = 0;
 658                 tmp_bh.b_size = 1 << inode->i_blkbits;
 659                 err = jfs_get_block(inode, blk, &tmp_bh, 0);
 660                 if (err)
 661                         return err;
 662                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
 663                         memset(data, 0, tocopy);
 664                 else {
 665                         bh = sb_bread(sb, tmp_bh.b_blocknr);
 666                         if (!bh)
 667                                 return -EIO;
 668                         memcpy(data, bh->b_data+offset, tocopy);
 669                         brelse(bh);
 670                 }
 671                 offset = 0;
 672                 toread -= tocopy;
 673                 data += tocopy;
 674                 blk++;
 675         }
 676         return len;
 677 }
 678
 679 /* Write to quotafile */
 680 static ssize_t jfs_quota_write(struct super_block *sb, int type,
 681                                const char *data, size_t len, loff_t off)
 682 {
 683         struct inode *inode = sb_dqopt(sb)->files[type];
 684         sector_t blk = off >> sb->s_blocksize_bits;
 685         int err = 0;
 686         int offset = off & (sb->s_blocksize - 1);
 687         int tocopy;
 688         size_t towrite = len;
 689         struct buffer_head tmp_bh;
 690         struct buffer_head *bh;
 691
 692         mutex_lock(&inode->i_mutex);
 693         while (towrite > 0) {
 694                 tocopy = sb->s_blocksize - offset < towrite ?
 695                                 sb->s_blocksize - offset : towrite;
 696
 697                 tmp_bh.b_state = 0;
 698                 tmp_bh.b_size = 1 << inode->i_blkbits;
 699                 err = jfs_get_block(inode, blk, &tmp_bh, 1);
 700                 if (err)
 701                         goto out;
 702                 if (offset || tocopy != sb->s_blocksize)
 703                         bh = sb_bread(sb, tmp_bh.b_blocknr);
 704                 else
 705                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
 706                 if (!bh) {
 707                         err = -EIO;
 708                         goto out;
 709                 }
 710                 lock_buffer(bh);
 711                 memcpy(bh->b_data+offset, data, tocopy);
 712                 flush_dcache_page(bh->b_page);
 713                 set_buffer_uptodate(bh);
 714                 mark_buffer_dirty(bh);
 715                 unlock_buffer(bh);
 716                 brelse(bh);
 717                 offset = 0;
 718                 towrite -= tocopy;
 719                 data += tocopy;
 720                 blk++;
 721         }
 722 out:
 723         if (len == towrite)
 724                 return err;
 725         if (inode->i_size < off+len-towrite)
 726                 i_size_write(inode, off+len-towrite);
 727         inode->i_version++;
 728         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 729         mark_inode_dirty(inode);
 730         mutex_unlock(&inode->i_mutex);
 731         return len - towrite;
 732 }
 733
 734 #endif
 735
 736 static struct super_operations jfs_super_operations = {
 737         .alloc_inode    = jfs_alloc_inode,
 738         .destroy_inode  = jfs_destroy_inode,
 739         .read_inode     = jfs_read_inode,
 740         .dirty_inode    = jfs_dirty_inode,
 741         .write_inode    = jfs_write_inode,
 742         .delete_inode   = jfs_delete_inode,
 743         .put_super      = jfs_put_super,
 744         .sync_fs        = jfs_sync_fs,
 745         .write_super_lockfs = jfs_write_super_lockfs,
 746         .unlockfs       = jfs_unlockfs,
 747         .statfs         = jfs_statfs,
 748         .remount_fs     = jfs_remount,
 749         .show_options   = jfs_show_options,
 750 #ifdef CONFIG_QUOTA
 751         .quota_read     = jfs_quota_read,
 752         .quota_write    = jfs_quota_write,
 753 #endif
 754 };
 755
 756 static struct export_operations jfs_export_operations = {
 757         .get_parent     = jfs_get_parent,
 758 };
 759
 760 static struct file_system_type jfs_fs_type = {
 761         .owner          = THIS_MODULE,
 762         .name           = "jfs",
 763         .get_sb         = jfs_get_sb,
 764         .kill_sb        = kill_block_super,
 765         .fs_flags       = FS_REQUIRES_DEV,
 766 };
 767
 768 static void init_once(void *foo, kmem_cache_t * cachep, unsigned long flags)
 769 {
 770         struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
 771
 772         if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
 773             SLAB_CTOR_CONSTRUCTOR) {
 774                 memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
 775                 INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
 776                 init_rwsem(&jfs_ip->rdwrlock);
 777                 mutex_init(&jfs_ip->commit_mutex);
 778                 init_rwsem(&jfs_ip->xattr_sem);
 779                 spin_lock_init(&jfs_ip->ag_lock);
 780                 jfs_ip->active_ag = -1;
 781 #ifdef CONFIG_JFS_POSIX_ACL
 782                 jfs_ip->i_acl = JFS_ACL_NOT_CACHED;
 783                 jfs_ip->i_default_acl = JFS_ACL_NOT_CACHED;
 784 #endif
 785                 inode_init_once(&jfs_ip->vfs_inode);
 786         }
 787 }
 788
 789 static int __init init_jfs_fs(void)
 790 {
 791         int i;
 792         int rc;
 793
 794         jfs_inode_cachep =
 795             kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
 796                             SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 797                             init_once, NULL);
 798         if (jfs_inode_cachep == NULL)
 799                 return -ENOMEM;
 800
 801         /*
 802          * Metapage initialization
 803          */
 804         rc = metapage_init();
 805         if (rc) {
 806                 jfs_err("metapage_init failed w/rc = %d", rc);
 807                 goto free_slab;
 808         }
 809
 810         /*
 811          * Transaction Manager initialization
 812          */
 813         rc = txInit();
 814         if (rc) {
 815                 jfs_err("txInit failed w/rc = %d", rc);
 816                 goto free_metapage;
 817         }
 818
 819         /*
 820          * I/O completion thread (endio)
 821          */
 822         jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
 823         if (IS_ERR(jfsIOthread)) {
 824                 rc = PTR_ERR(jfsIOthread);
 825                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 826                 goto end_txmngr;
 827         }
 828
 829         if (commit_threads < 1)
 830                 commit_threads = num_online_cpus();
 831         if (commit_threads > MAX_COMMIT_THREADS)
 832                 commit_threads = MAX_COMMIT_THREADS;
 833
 834         for (i = 0; i < commit_threads; i++) {
 835                 jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
 836                 if (IS_ERR(jfsCommitThread[i])) {
 837                         rc = PTR_ERR(jfsCommitThread[i]);
 838                         jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 839                         commit_threads = i;
 840                         goto kill_committask;
 841                 }
 842         }
 843
 844         jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
 845         if (IS_ERR(jfsSyncThread)) {
 846                 rc = PTR_ERR(jfsSyncThread);
 847                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 848                 goto kill_committask;
 849         }
 850
 851 #ifdef PROC_FS_JFS
 852         jfs_proc_init();
 853 #endif
 854
 855         return register_filesystem(&jfs_fs_type);
 856
 857 kill_committask:
 858         for (i = 0; i < commit_threads; i++)
 859                 kthread_stop(jfsCommitThread[i]);
 860         kthread_stop(jfsIOthread);
 861 end_txmngr:
 862         txExit();
 863 free_metapage:
 864         metapage_exit();
 865 free_slab:
 866         kmem_cache_destroy(jfs_inode_cachep);
 867         return rc;
 868 }
 869
 870 static void __exit exit_jfs_fs(void)
 871 {
 872         int i;
 873
 874         jfs_info("exit_jfs_fs called");
 875
 876         txExit();
 877         metapage_exit();
 878
 879         kthread_stop(jfsIOthread);
 880         for (i = 0; i < commit_threads; i++)
 881                 kthread_stop(jfsCommitThread[i]);
 882         kthread_stop(jfsSyncThread);
 883 #ifdef PROC_FS_JFS
 884         jfs_proc_clean();
 885 #endif
 886         unregister_filesystem(&jfs_fs_type);
 887         kmem_cache_destroy(jfs_inode_cachep);
 888 }
 889
 890 module_init(init_jfs_fs)
 891 module_exit(exit_jfs_fs)