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