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/quotaops.h>
  26 #include <linux/mount.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/kthread.h>
  29 #include <linux/posix_acl.h>
  30 #include <linux/buffer_head.h>
  31 #include <linux/exportfs.h>
  32 #include <linux/crc32.h>
  33 #include <asm/uaccess.h>
  34 #include <linux/seq_file.h>
  35
  36 #include "jfs_incore.h"
  37 #include "jfs_filsys.h"
  38 #include "jfs_inode.h"
  39 #include "jfs_metapage.h"
  40 #include "jfs_superblock.h"
  41 #include "jfs_dmap.h"
  42 #include "jfs_imap.h"
  43 #include "jfs_acl.h"
  44 #include "jfs_debug.h"
  45
  46 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
  47 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
  48 MODULE_LICENSE("GPL");
  49
  50 static struct kmem_cache * jfs_inode_cachep;
  51
  52 static const struct super_operations jfs_super_operations;
  53 static const struct export_operations jfs_export_operations;
  54 static struct file_system_type jfs_fs_type;
  55
  56 #define MAX_COMMIT_THREADS 64
  57 static int commit_threads = 0;
  58 module_param(commit_threads, int, 0);
  59 MODULE_PARM_DESC(commit_threads, "Number of commit threads");
  60
  61 static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
  62 struct task_struct *jfsIOthread;
  63 struct task_struct *jfsSyncThread;
  64
  65 #ifdef CONFIG_JFS_DEBUG
  66 int jfsloglevel = JFS_LOGLEVEL_WARN;
  67 module_param(jfsloglevel, int, 0644);
  68 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
  69 #endif
  70
  71 static void jfs_handle_error(struct super_block *sb)
  72 {
  73         struct jfs_sb_info *sbi = JFS_SBI(sb);
  74
  75         if (sb->s_flags & MS_RDONLY)
  76                 return;
  77
  78         updateSuper(sb, FM_DIRTY);
  79
  80         if (sbi->flag & JFS_ERR_PANIC)
  81                 panic("JFS (device %s): panic forced after error\n",
  82                         sb->s_id);
  83         else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
  84                 jfs_err("ERROR: (device %s): remounting filesystem "
  85                         "as read-only\n",
  86                         sb->s_id);
  87                 sb->s_flags |= MS_RDONLY;
  88         }
  89
  90         /* nothing is done for continue beyond marking the superblock dirty */
  91 }
  92
  93 void jfs_error(struct super_block *sb, const char * function, ...)
  94 {
  95         static char error_buf[256];
  96         va_list args;
  97
  98         va_start(args, function);
  99         vsnprintf(error_buf, sizeof(error_buf), function, args);
 100         va_end(args);
 101
 102         printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
 103
 104         jfs_handle_error(sb);
 105 }
 106
 107 static struct inode *jfs_alloc_inode(struct super_block *sb)
 108 {
 109         struct jfs_inode_info *jfs_inode;
 110
 111         jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
 112         if (!jfs_inode)
 113                 return NULL;
 114         return &jfs_inode->vfs_inode;
 115 }
 116
 117 static void jfs_destroy_inode(struct inode *inode)
 118 {
 119         struct jfs_inode_info *ji = JFS_IP(inode);
 120
 121         BUG_ON(!list_empty(&ji->anon_inode_list));
 122
 123         spin_lock_irq(&ji->ag_lock);
 124         if (ji->active_ag != -1) {
 125                 struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
 126                 atomic_dec(&bmap->db_active[ji->active_ag]);
 127                 ji->active_ag = -1;
 128         }
 129         spin_unlock_irq(&ji->ag_lock);
 130
 131 #ifdef CONFIG_JFS_POSIX_ACL
 132         if (ji->i_acl != JFS_ACL_NOT_CACHED) {
 133                 posix_acl_release(ji->i_acl);
 134                 ji->i_acl = JFS_ACL_NOT_CACHED;
 135         }
 136         if (ji->i_default_acl != JFS_ACL_NOT_CACHED) {
 137                 posix_acl_release(ji->i_default_acl);
 138                 ji->i_default_acl = JFS_ACL_NOT_CACHED;
 139         }
 140 #endif
 141
 142         kmem_cache_free(jfs_inode_cachep, ji);
 143 }
 144
 145 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 146 {
 147         struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
 148         s64 maxinodes;
 149         struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
 150
 151         jfs_info("In jfs_statfs");
 152         buf->f_type = JFS_SUPER_MAGIC;
 153         buf->f_bsize = sbi->bsize;
 154         buf->f_blocks = sbi->bmap->db_mapsize;
 155         buf->f_bfree = sbi->bmap->db_nfree;
 156         buf->f_bavail = sbi->bmap->db_nfree;
 157         /*
 158          * If we really return the number of allocated & free inodes, some
 159          * applications will fail because they won't see enough free inodes.
 160          * We'll try to calculate some guess as to how may inodes we can
 161          * really allocate
 162          *
 163          * buf->f_files = atomic_read(&imap->im_numinos);
 164          * buf->f_ffree = atomic_read(&imap->im_numfree);
 165          */
 166         maxinodes = min((s64) atomic_read(&imap->im_numinos) +
 167                         ((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
 168                          << L2INOSPEREXT), (s64) 0xffffffffLL);
 169         buf->f_files = maxinodes;
 170         buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
 171                                     atomic_read(&imap->im_numfree));
 172         buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
 173         buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
 174                                         sizeof(sbi->uuid)/2);
 175
 176         buf->f_namelen = JFS_NAME_MAX;
 177         return 0;
 178 }
 179
 180 static void jfs_put_super(struct super_block *sb)
 181 {
 182         struct jfs_sb_info *sbi = JFS_SBI(sb);
 183         int rc;
 184
 185         jfs_info("In jfs_put_super");
 186         rc = jfs_umount(sb);
 187         if (rc)
 188                 jfs_err("jfs_umount failed with return code %d", rc);
 189         if (sbi->nls_tab)
 190                 unload_nls(sbi->nls_tab);
 191         sbi->nls_tab = NULL;
 192
 193         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 194         iput(sbi->direct_inode);
 195         sbi->direct_inode = NULL;
 196
 197         kfree(sbi);
 198 }
 199
 200 enum {
 201         Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
 202         Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
 203         Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
 204 };
 205
 206 static const match_table_t tokens = {
 207         {Opt_integrity, "integrity"},
 208         {Opt_nointegrity, "nointegrity"},
 209         {Opt_iocharset, "iocharset=%s"},
 210         {Opt_resize, "resize=%u"},
 211         {Opt_resize_nosize, "resize"},
 212         {Opt_errors, "errors=%s"},
 213         {Opt_ignore, "noquota"},
 214         {Opt_ignore, "quota"},
 215         {Opt_usrquota, "usrquota"},
 216         {Opt_grpquota, "grpquota"},
 217         {Opt_uid, "uid=%u"},
 218         {Opt_gid, "gid=%u"},
 219         {Opt_umask, "umask=%u"},
 220         {Opt_err, NULL}
 221 };
 222
 223 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
 224                          int *flag)
 225 {
 226         void *nls_map = (void *)-1;     /* -1: no change;  NULL: none */
 227         char *p;
 228         struct jfs_sb_info *sbi = JFS_SBI(sb);
 229
 230         *newLVSize = 0;
 231
 232         if (!options)
 233                 return 1;
 234
 235         while ((p = strsep(&options, ",")) != NULL) {
 236                 substring_t args[MAX_OPT_ARGS];
 237                 int token;
 238                 if (!*p)
 239                         continue;
 240
 241                 token = match_token(p, tokens, args);
 242                 switch (token) {
 243                 case Opt_integrity:
 244                         *flag &= ~JFS_NOINTEGRITY;
 245                         break;
 246                 case Opt_nointegrity:
 247                         *flag |= JFS_NOINTEGRITY;
 248                         break;
 249                 case Opt_ignore:
 250                         /* Silently ignore the quota options */
 251                         /* Don't do anything ;-) */
 252                         break;
 253                 case Opt_iocharset:
 254                         if (nls_map && nls_map != (void *) -1)
 255                                 unload_nls(nls_map);
 256                         if (!strcmp(args[0].from, "none"))
 257                                 nls_map = NULL;
 258                         else {
 259                                 nls_map = load_nls(args[0].from);
 260                                 if (!nls_map) {
 261                                         printk(KERN_ERR
 262                                                "JFS: charset not found\n");
 263                                         goto cleanup;
 264                                 }
 265                         }
 266                         break;
 267                 case Opt_resize:
 268                 {
 269                         char *resize = args[0].from;
 270                         *newLVSize = simple_strtoull(resize, &resize, 0);
 271                         break;
 272                 }
 273                 case Opt_resize_nosize:
 274                 {
 275                         *newLVSize = sb->s_bdev->bd_inode->i_size >>
 276                                 sb->s_blocksize_bits;
 277                         if (*newLVSize == 0)
 278                                 printk(KERN_ERR
 279                                        "JFS: Cannot determine volume size\n");
 280                         break;
 281                 }
 282                 case Opt_errors:
 283                 {
 284                         char *errors = args[0].from;
 285                         if (!errors || !*errors)
 286                                 goto cleanup;
 287                         if (!strcmp(errors, "continue")) {
 288                                 *flag &= ~JFS_ERR_REMOUNT_RO;
 289                                 *flag &= ~JFS_ERR_PANIC;
 290                                 *flag |= JFS_ERR_CONTINUE;
 291                         } else if (!strcmp(errors, "remount-ro")) {
 292                                 *flag &= ~JFS_ERR_CONTINUE;
 293                                 *flag &= ~JFS_ERR_PANIC;
 294                                 *flag |= JFS_ERR_REMOUNT_RO;
 295                         } else if (!strcmp(errors, "panic")) {
 296                                 *flag &= ~JFS_ERR_CONTINUE;
 297                                 *flag &= ~JFS_ERR_REMOUNT_RO;
 298                                 *flag |= JFS_ERR_PANIC;
 299                         } else {
 300                                 printk(KERN_ERR
 301                                        "JFS: %s is an invalid error handler\n",
 302                                        errors);
 303                                 goto cleanup;
 304                         }
 305                         break;
 306                 }
 307
 308 #ifdef CONFIG_QUOTA
 309                 case Opt_quota:
 310                 case Opt_usrquota:
 311                         *flag |= JFS_USRQUOTA;
 312                         break;
 313                 case Opt_grpquota:
 314                         *flag |= JFS_GRPQUOTA;
 315                         break;
 316 #else
 317                 case Opt_usrquota:
 318                 case Opt_grpquota:
 319                 case Opt_quota:
 320                         printk(KERN_ERR
 321                                "JFS: quota operations not supported\n");
 322                         break;
 323 #endif
 324                 case Opt_uid:
 325                 {
 326                         char *uid = args[0].from;
 327                         sbi->uid = simple_strtoul(uid, &uid, 0);
 328                         break;
 329                 }
 330                 case Opt_gid:
 331                 {
 332                         char *gid = args[0].from;
 333                         sbi->gid = simple_strtoul(gid, &gid, 0);
 334                         break;
 335                 }
 336                 case Opt_umask:
 337                 {
 338                         char *umask = args[0].from;
 339                         sbi->umask = simple_strtoul(umask, &umask, 8);
 340                         if (sbi->umask & ~0777) {
 341                                 printk(KERN_ERR
 342                                        "JFS: Invalid value of umask\n");
 343                                 goto cleanup;
 344                         }
 345                         break;
 346                 }
 347                 default:
 348                         printk("jfs: Unrecognized mount option \"%s\" "
 349                                         " or missing value\n", p);
 350                         goto cleanup;
 351                 }
 352         }
 353
 354         if (nls_map != (void *) -1) {
 355                 /* Discard old (if remount) */
 356                 if (sbi->nls_tab)
 357                         unload_nls(sbi->nls_tab);
 358                 sbi->nls_tab = nls_map;
 359         }
 360         return 1;
 361
 362 cleanup:
 363         if (nls_map && nls_map != (void *) -1)
 364                 unload_nls(nls_map);
 365         return 0;
 366 }
 367
 368 static int jfs_remount(struct super_block *sb, int *flags, char *data)
 369 {
 370         s64 newLVSize = 0;
 371         int rc = 0;
 372         int flag = JFS_SBI(sb)->flag;
 373
 374         if (!parse_options(data, sb, &newLVSize, &flag)) {
 375                 return -EINVAL;
 376         }
 377         if (newLVSize) {
 378                 if (sb->s_flags & MS_RDONLY) {
 379                         printk(KERN_ERR
 380                   "JFS: resize requires volume to be mounted read-write\n");
 381                         return -EROFS;
 382                 }
 383                 rc = jfs_extendfs(sb, newLVSize, 0);
 384                 if (rc)
 385                         return rc;
 386         }
 387
 388         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
 389                 /*
 390                  * Invalidate any previously read metadata.  fsck may have
 391                  * changed the on-disk data since we mounted r/o
 392                  */
 393                 truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
 394
 395                 JFS_SBI(sb)->flag = flag;
 396                 return jfs_mount_rw(sb, 1);
 397         }
 398         if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
 399                 rc = jfs_umount_rw(sb);
 400                 JFS_SBI(sb)->flag = flag;
 401                 return rc;
 402         }
 403         if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
 404                 if (!(sb->s_flags & MS_RDONLY)) {
 405                         rc = jfs_umount_rw(sb);
 406                         if (rc)
 407                                 return rc;
 408                         JFS_SBI(sb)->flag = flag;
 409                         return jfs_mount_rw(sb, 1);
 410                 }
 411         JFS_SBI(sb)->flag = flag;
 412
 413         return 0;
 414 }
 415
 416 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 417 {
 418         struct jfs_sb_info *sbi;
 419         struct inode *inode;
 420         int rc;
 421         s64 newLVSize = 0;
 422         int flag, ret = -EINVAL;
 423
 424         jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
 425
 426         if (!new_valid_dev(sb->s_bdev->bd_dev))
 427                 return -EOVERFLOW;
 428
 429         sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
 430         if (!sbi)
 431                 return -ENOMEM;
 432         sb->s_fs_info = sbi;
 433         sbi->sb = sb;
 434         sbi->uid = sbi->gid = sbi->umask = -1;
 435
 436         /* initialize the mount flag and determine the default error handler */
 437         flag = JFS_ERR_REMOUNT_RO;
 438
 439         if (!parse_options((char *) data, sb, &newLVSize, &flag)) {
 440                 kfree(sbi);
 441                 return -EINVAL;
 442         }
 443         sbi->flag = flag;
 444
 445 #ifdef CONFIG_JFS_POSIX_ACL
 446         sb->s_flags |= MS_POSIXACL;
 447 #endif
 448
 449         if (newLVSize) {
 450                 printk(KERN_ERR "resize option for remount only\n");
 451                 return -EINVAL;
 452         }
 453
 454         /*
 455          * Initialize blocksize to 4K.
 456          */
 457         sb_set_blocksize(sb, PSIZE);
 458
 459         /*
 460          * Set method vectors.
 461          */
 462         sb->s_op = &jfs_super_operations;
 463         sb->s_export_op = &jfs_export_operations;
 464
 465         /*
 466          * Initialize direct-mapping inode/address-space
 467          */
 468         inode = new_inode(sb);
 469         if (inode == NULL) {
 470                 ret = -ENOMEM;
 471                 goto out_kfree;
 472         }
 473         inode->i_ino = 0;
 474         inode->i_nlink = 1;
 475         inode->i_size = sb->s_bdev->bd_inode->i_size;
 476         inode->i_mapping->a_ops = &jfs_metapage_aops;
 477         insert_inode_hash(inode);
 478         mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
 479
 480         sbi->direct_inode = inode;
 481
 482         rc = jfs_mount(sb);
 483         if (rc) {
 484                 if (!silent) {
 485                         jfs_err("jfs_mount failed w/return code = %d", rc);
 486                 }
 487                 goto out_mount_failed;
 488         }
 489         if (sb->s_flags & MS_RDONLY)
 490                 sbi->log = NULL;
 491         else {
 492                 rc = jfs_mount_rw(sb, 0);
 493                 if (rc) {
 494                         if (!silent) {
 495                                 jfs_err("jfs_mount_rw failed, return code = %d",
 496                                         rc);
 497                         }
 498                         goto out_no_rw;
 499                 }
 500         }
 501
 502         sb->s_magic = JFS_SUPER_MAGIC;
 503
 504         inode = jfs_iget(sb, ROOT_I);
 505         if (IS_ERR(inode)) {
 506                 ret = PTR_ERR(inode);
 507                 goto out_no_rw;
 508         }
 509         sb->s_root = d_alloc_root(inode);
 510         if (!sb->s_root)
 511                 goto out_no_root;
 512
 513         if (sbi->mntflag & JFS_OS2)
 514                 sb->s_root->d_op = &jfs_ci_dentry_operations;
 515
 516         /* logical blocks are represented by 40 bits in pxd_t, etc. */
 517         sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
 518 #if BITS_PER_LONG == 32
 519         /*
 520          * Page cache is indexed by long.
 521          * I would use MAX_LFS_FILESIZE, but it's only half as big
 522          */
 523         sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, sb->s_maxbytes);
 524 #endif
 525         sb->s_time_gran = 1;
 526         return 0;
 527
 528 out_no_root:
 529         jfs_err("jfs_read_super: get root dentry failed");
 530         iput(inode);
 531
 532 out_no_rw:
 533         rc = jfs_umount(sb);
 534         if (rc) {
 535                 jfs_err("jfs_umount failed with return code %d", rc);
 536         }
 537 out_mount_failed:
 538         filemap_write_and_wait(sbi->direct_inode->i_mapping);
 539         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 540         make_bad_inode(sbi->direct_inode);
 541         iput(sbi->direct_inode);
 542         sbi->direct_inode = NULL;
 543 out_kfree:
 544         if (sbi->nls_tab)
 545                 unload_nls(sbi->nls_tab);
 546         kfree(sbi);
 547         return ret;
 548 }
 549
 550 static int jfs_freeze(struct super_block *sb)
 551 {
 552         struct jfs_sb_info *sbi = JFS_SBI(sb);
 553         struct jfs_log *log = sbi->log;
 554
 555         if (!(sb->s_flags & MS_RDONLY)) {
 556                 txQuiesce(sb);
 557                 lmLogShutdown(log);
 558                 updateSuper(sb, FM_CLEAN);
 559         }
 560         return 0;
 561 }
 562
 563 static int jfs_unfreeze(struct super_block *sb)
 564 {
 565         struct jfs_sb_info *sbi = JFS_SBI(sb);
 566         struct jfs_log *log = sbi->log;
 567         int rc = 0;
 568
 569         if (!(sb->s_flags & MS_RDONLY)) {
 570                 updateSuper(sb, FM_MOUNT);
 571                 if ((rc = lmLogInit(log)))
 572                         jfs_err("jfs_unlock failed with return code %d", rc);
 573                 else
 574                         txResume(sb);
 575         }
 576         return 0;
 577 }
 578
 579 static int jfs_get_sb(struct file_system_type *fs_type,
 580         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 581 {
 582         return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
 583                            mnt);
 584 }
 585
 586 static int jfs_sync_fs(struct super_block *sb, int wait)
 587 {
 588         struct jfs_log *log = JFS_SBI(sb)->log;
 589
 590         /* log == NULL indicates read-only mount */
 591         if (log) {
 592                 jfs_flush_journal(log, wait);
 593                 jfs_syncpt(log, 0);
 594         }
 595
 596         return 0;
 597 }
 598
 599 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 600 {
 601         struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
 602
 603         if (sbi->uid != -1)
 604                 seq_printf(seq, ",uid=%d", sbi->uid);
 605         if (sbi->gid != -1)
 606                 seq_printf(seq, ",gid=%d", sbi->gid);
 607         if (sbi->umask != -1)
 608                 seq_printf(seq, ",umask=%03o", sbi->umask);
 609         if (sbi->flag & JFS_NOINTEGRITY)
 610                 seq_puts(seq, ",nointegrity");
 611         if (sbi->nls_tab)
 612                 seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
 613         if (sbi->flag & JFS_ERR_CONTINUE)
 614                 seq_printf(seq, ",errors=continue");
 615         if (sbi->flag & JFS_ERR_PANIC)
 616                 seq_printf(seq, ",errors=panic");
 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                 mutex_unlock(&inode->i_mutex);
 725                 return err;
 726         }
 727         if (inode->i_size < off+len-towrite)
 728                 i_size_write(inode, off+len-towrite);
 729         inode->i_version++;
 730         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 731         mark_inode_dirty(inode);
 732         mutex_unlock(&inode->i_mutex);
 733         return len - towrite;
 734 }
 735
 736 #endif
 737
 738 static const struct super_operations jfs_super_operations = {
 739         .alloc_inode    = jfs_alloc_inode,
 740         .destroy_inode  = jfs_destroy_inode,
 741         .dirty_inode    = jfs_dirty_inode,
 742         .write_inode    = jfs_write_inode,
 743         .delete_inode   = jfs_delete_inode,
 744         .put_super      = jfs_put_super,
 745         .sync_fs        = jfs_sync_fs,
 746         .freeze_fs      = jfs_freeze,
 747         .unfreeze_fs    = jfs_unfreeze,
 748         .statfs         = jfs_statfs,
 749         .remount_fs     = jfs_remount,
 750         .show_options   = jfs_show_options,
 751 #ifdef CONFIG_QUOTA
 752         .quota_read     = jfs_quota_read,
 753         .quota_write    = jfs_quota_write,
 754 #endif
 755 };
 756
 757 static const struct export_operations jfs_export_operations = {
 758         .fh_to_dentry   = jfs_fh_to_dentry,
 759         .fh_to_parent   = jfs_fh_to_parent,
 760         .get_parent     = jfs_get_parent,
 761 };
 762
 763 static struct file_system_type jfs_fs_type = {
 764         .owner          = THIS_MODULE,
 765         .name           = "jfs",
 766         .get_sb         = jfs_get_sb,
 767         .kill_sb        = kill_block_super,
 768         .fs_flags       = FS_REQUIRES_DEV,
 769 };
 770
 771 static void init_once(void *foo)
 772 {
 773         struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
 774
 775         memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
 776         INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
 777         init_rwsem(&jfs_ip->rdwrlock);
 778         mutex_init(&jfs_ip->commit_mutex);
 779         init_rwsem(&jfs_ip->xattr_sem);
 780         spin_lock_init(&jfs_ip->ag_lock);
 781         jfs_ip->active_ag = -1;
 782 #ifdef CONFIG_JFS_POSIX_ACL
 783         jfs_ip->i_acl = JFS_ACL_NOT_CACHED;
 784         jfs_ip->i_default_acl = JFS_ACL_NOT_CACHED;
 785 #endif
 786         inode_init_once(&jfs_ip->vfs_inode);
 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);
 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)