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