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
 187         lock_kernel();
 188
 189         rc = jfs_umount(sb);
 190         if (rc)
 191                 jfs_err("jfs_umount failed with return code %d", rc);
 192         if (sbi->nls_tab)
 193                 unload_nls(sbi->nls_tab);
 194         sbi->nls_tab = NULL;
 195
 196         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 197         iput(sbi->direct_inode);
 198         sbi->direct_inode = NULL;
 199
 200         kfree(sbi);
 201
 202         unlock_kernel();
 203 }
 204
 205 enum {
 206         Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
 207         Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
 208         Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
 209 };
 210
 211 static const match_table_t tokens = {
 212         {Opt_integrity, "integrity"},
 213         {Opt_nointegrity, "nointegrity"},
 214         {Opt_iocharset, "iocharset=%s"},
 215         {Opt_resize, "resize=%u"},
 216         {Opt_resize_nosize, "resize"},
 217         {Opt_errors, "errors=%s"},
 218         {Opt_ignore, "noquota"},
 219         {Opt_ignore, "quota"},
 220         {Opt_usrquota, "usrquota"},
 221         {Opt_grpquota, "grpquota"},
 222         {Opt_uid, "uid=%u"},
 223         {Opt_gid, "gid=%u"},
 224         {Opt_umask, "umask=%u"},
 225         {Opt_err, NULL}
 226 };
 227
 228 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
 229                          int *flag)
 230 {
 231         void *nls_map = (void *)-1;     /* -1: no change;  NULL: none */
 232         char *p;
 233         struct jfs_sb_info *sbi = JFS_SBI(sb);
 234
 235         *newLVSize = 0;
 236
 237         if (!options)
 238                 return 1;
 239
 240         while ((p = strsep(&options, ",")) != NULL) {
 241                 substring_t args[MAX_OPT_ARGS];
 242                 int token;
 243                 if (!*p)
 244                         continue;
 245
 246                 token = match_token(p, tokens, args);
 247                 switch (token) {
 248                 case Opt_integrity:
 249                         *flag &= ~JFS_NOINTEGRITY;
 250                         break;
 251                 case Opt_nointegrity:
 252                         *flag |= JFS_NOINTEGRITY;
 253                         break;
 254                 case Opt_ignore:
 255                         /* Silently ignore the quota options */
 256                         /* Don't do anything ;-) */
 257                         break;
 258                 case Opt_iocharset:
 259                         if (nls_map && nls_map != (void *) -1)
 260                                 unload_nls(nls_map);
 261                         if (!strcmp(args[0].from, "none"))
 262                                 nls_map = NULL;
 263                         else {
 264                                 nls_map = load_nls(args[0].from);
 265                                 if (!nls_map) {
 266                                         printk(KERN_ERR
 267                                                "JFS: charset not found\n");
 268                                         goto cleanup;
 269                                 }
 270                         }
 271                         break;
 272                 case Opt_resize:
 273                 {
 274                         char *resize = args[0].from;
 275                         *newLVSize = simple_strtoull(resize, &resize, 0);
 276                         break;
 277                 }
 278                 case Opt_resize_nosize:
 279                 {
 280                         *newLVSize = sb->s_bdev->bd_inode->i_size >>
 281                                 sb->s_blocksize_bits;
 282                         if (*newLVSize == 0)
 283                                 printk(KERN_ERR
 284                                        "JFS: Cannot determine volume size\n");
 285                         break;
 286                 }
 287                 case Opt_errors:
 288                 {
 289                         char *errors = args[0].from;
 290                         if (!errors || !*errors)
 291                                 goto cleanup;
 292                         if (!strcmp(errors, "continue")) {
 293                                 *flag &= ~JFS_ERR_REMOUNT_RO;
 294                                 *flag &= ~JFS_ERR_PANIC;
 295                                 *flag |= JFS_ERR_CONTINUE;
 296                         } else if (!strcmp(errors, "remount-ro")) {
 297                                 *flag &= ~JFS_ERR_CONTINUE;
 298                                 *flag &= ~JFS_ERR_PANIC;
 299                                 *flag |= JFS_ERR_REMOUNT_RO;
 300                         } else if (!strcmp(errors, "panic")) {
 301                                 *flag &= ~JFS_ERR_CONTINUE;
 302                                 *flag &= ~JFS_ERR_REMOUNT_RO;
 303                                 *flag |= JFS_ERR_PANIC;
 304                         } else {
 305                                 printk(KERN_ERR
 306                                        "JFS: %s is an invalid error handler\n",
 307                                        errors);
 308                                 goto cleanup;
 309                         }
 310                         break;
 311                 }
 312
 313 #ifdef CONFIG_QUOTA
 314                 case Opt_quota:
 315                 case Opt_usrquota:
 316                         *flag |= JFS_USRQUOTA;
 317                         break;
 318                 case Opt_grpquota:
 319                         *flag |= JFS_GRPQUOTA;
 320                         break;
 321 #else
 322                 case Opt_usrquota:
 323                 case Opt_grpquota:
 324                 case Opt_quota:
 325                         printk(KERN_ERR
 326                                "JFS: quota operations not supported\n");
 327                         break;
 328 #endif
 329                 case Opt_uid:
 330                 {
 331                         char *uid = args[0].from;
 332                         sbi->uid = simple_strtoul(uid, &uid, 0);
 333                         break;
 334                 }
 335                 case Opt_gid:
 336                 {
 337                         char *gid = args[0].from;
 338                         sbi->gid = simple_strtoul(gid, &gid, 0);
 339                         break;
 340                 }
 341                 case Opt_umask:
 342                 {
 343                         char *umask = args[0].from;
 344                         sbi->umask = simple_strtoul(umask, &umask, 8);
 345                         if (sbi->umask & ~0777) {
 346                                 printk(KERN_ERR
 347                                        "JFS: Invalid value of umask\n");
 348                                 goto cleanup;
 349                         }
 350                         break;
 351                 }
 352                 default:
 353                         printk("jfs: Unrecognized mount option \"%s\" "
 354                                         " or missing value\n", p);
 355                         goto cleanup;
 356                 }
 357         }
 358
 359         if (nls_map != (void *) -1) {
 360                 /* Discard old (if remount) */
 361                 if (sbi->nls_tab)
 362                         unload_nls(sbi->nls_tab);
 363                 sbi->nls_tab = nls_map;
 364         }
 365         return 1;
 366
 367 cleanup:
 368         if (nls_map && nls_map != (void *) -1)
 369                 unload_nls(nls_map);
 370         return 0;
 371 }
 372
 373 static int jfs_remount(struct super_block *sb, int *flags, char *data)
 374 {
 375         s64 newLVSize = 0;
 376         int rc = 0;
 377         int flag = JFS_SBI(sb)->flag;
 378
 379         if (!parse_options(data, sb, &newLVSize, &flag)) {
 380                 return -EINVAL;
 381         }
 382         if (newLVSize) {
 383                 if (sb->s_flags & MS_RDONLY) {
 384                         printk(KERN_ERR
 385                   "JFS: resize requires volume to be mounted read-write\n");
 386                         return -EROFS;
 387                 }
 388                 rc = jfs_extendfs(sb, newLVSize, 0);
 389                 if (rc)
 390                         return rc;
 391         }
 392
 393         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
 394                 /*
 395                  * Invalidate any previously read metadata.  fsck may have
 396                  * changed the on-disk data since we mounted r/o
 397                  */
 398                 truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
 399
 400                 JFS_SBI(sb)->flag = flag;
 401                 return jfs_mount_rw(sb, 1);
 402         }
 403         if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
 404                 rc = jfs_umount_rw(sb);
 405                 JFS_SBI(sb)->flag = flag;
 406                 return rc;
 407         }
 408         if ((JFS_SBI(sb)->flag & JFS_NOINTEGRITY) != (flag & JFS_NOINTEGRITY))
 409                 if (!(sb->s_flags & MS_RDONLY)) {
 410                         rc = jfs_umount_rw(sb);
 411                         if (rc)
 412                                 return rc;
 413                         JFS_SBI(sb)->flag = flag;
 414                         return jfs_mount_rw(sb, 1);
 415                 }
 416         JFS_SBI(sb)->flag = flag;
 417
 418         return 0;
 419 }
 420
 421 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 422 {
 423         struct jfs_sb_info *sbi;
 424         struct inode *inode;
 425         int rc;
 426         s64 newLVSize = 0;
 427         int flag, ret = -EINVAL;
 428
 429         jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
 430
 431         if (!new_valid_dev(sb->s_bdev->bd_dev))
 432                 return -EOVERFLOW;
 433
 434         sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
 435         if (!sbi)
 436                 return -ENOMEM;
 437         sb->s_fs_info = sbi;
 438         sbi->sb = sb;
 439         sbi->uid = sbi->gid = sbi->umask = -1;
 440
 441         /* initialize the mount flag and determine the default error handler */
 442         flag = JFS_ERR_REMOUNT_RO;
 443
 444         if (!parse_options((char *) data, sb, &newLVSize, &flag)) {
 445                 kfree(sbi);
 446                 return -EINVAL;
 447         }
 448         sbi->flag = flag;
 449
 450 #ifdef CONFIG_JFS_POSIX_ACL
 451         sb->s_flags |= MS_POSIXACL;
 452 #endif
 453
 454         if (newLVSize) {
 455                 printk(KERN_ERR "resize option for remount only\n");
 456                 return -EINVAL;
 457         }
 458
 459         /*
 460          * Initialize blocksize to 4K.
 461          */
 462         sb_set_blocksize(sb, PSIZE);
 463
 464         /*
 465          * Set method vectors.
 466          */
 467         sb->s_op = &jfs_super_operations;
 468         sb->s_export_op = &jfs_export_operations;
 469
 470         /*
 471          * Initialize direct-mapping inode/address-space
 472          */
 473         inode = new_inode(sb);
 474         if (inode == NULL) {
 475                 ret = -ENOMEM;
 476                 goto out_kfree;
 477         }
 478         inode->i_ino = 0;
 479         inode->i_nlink = 1;
 480         inode->i_size = sb->s_bdev->bd_inode->i_size;
 481         inode->i_mapping->a_ops = &jfs_metapage_aops;
 482         insert_inode_hash(inode);
 483         mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
 484
 485         sbi->direct_inode = inode;
 486
 487         rc = jfs_mount(sb);
 488         if (rc) {
 489                 if (!silent) {
 490                         jfs_err("jfs_mount failed w/return code = %d", rc);
 491                 }
 492                 goto out_mount_failed;
 493         }
 494         if (sb->s_flags & MS_RDONLY)
 495                 sbi->log = NULL;
 496         else {
 497                 rc = jfs_mount_rw(sb, 0);
 498                 if (rc) {
 499                         if (!silent) {
 500                                 jfs_err("jfs_mount_rw failed, return code = %d",
 501                                         rc);
 502                         }
 503                         goto out_no_rw;
 504                 }
 505         }
 506
 507         sb->s_magic = JFS_SUPER_MAGIC;
 508
 509         inode = jfs_iget(sb, ROOT_I);
 510         if (IS_ERR(inode)) {
 511                 ret = PTR_ERR(inode);
 512                 goto out_no_rw;
 513         }
 514         sb->s_root = d_alloc_root(inode);
 515         if (!sb->s_root)
 516                 goto out_no_root;
 517
 518         if (sbi->mntflag & JFS_OS2)
 519                 sb->s_root->d_op = &jfs_ci_dentry_operations;
 520
 521         /* logical blocks are represented by 40 bits in pxd_t, etc. */
 522         sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
 523 #if BITS_PER_LONG == 32
 524         /*
 525          * Page cache is indexed by long.
 526          * I would use MAX_LFS_FILESIZE, but it's only half as big
 527          */
 528         sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, sb->s_maxbytes);
 529 #endif
 530         sb->s_time_gran = 1;
 531         return 0;
 532
 533 out_no_root:
 534         jfs_err("jfs_read_super: get root dentry failed");
 535         iput(inode);
 536
 537 out_no_rw:
 538         rc = jfs_umount(sb);
 539         if (rc) {
 540                 jfs_err("jfs_umount failed with return code %d", rc);
 541         }
 542 out_mount_failed:
 543         filemap_write_and_wait(sbi->direct_inode->i_mapping);
 544         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 545         make_bad_inode(sbi->direct_inode);
 546         iput(sbi->direct_inode);
 547         sbi->direct_inode = NULL;
 548 out_kfree:
 549         if (sbi->nls_tab)
 550                 unload_nls(sbi->nls_tab);
 551         kfree(sbi);
 552         return ret;
 553 }
 554
 555 static int jfs_freeze(struct super_block *sb)
 556 {
 557         struct jfs_sb_info *sbi = JFS_SBI(sb);
 558         struct jfs_log *log = sbi->log;
 559
 560         if (!(sb->s_flags & MS_RDONLY)) {
 561                 txQuiesce(sb);
 562                 lmLogShutdown(log);
 563                 updateSuper(sb, FM_CLEAN);
 564         }
 565         return 0;
 566 }
 567
 568 static int jfs_unfreeze(struct super_block *sb)
 569 {
 570         struct jfs_sb_info *sbi = JFS_SBI(sb);
 571         struct jfs_log *log = sbi->log;
 572         int rc = 0;
 573
 574         if (!(sb->s_flags & MS_RDONLY)) {
 575                 updateSuper(sb, FM_MOUNT);
 576                 if ((rc = lmLogInit(log)))
 577                         jfs_err("jfs_unlock failed with return code %d", rc);
 578                 else
 579                         txResume(sb);
 580         }
 581         return 0;
 582 }
 583
 584 static int jfs_get_sb(struct file_system_type *fs_type,
 585         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 586 {
 587         return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
 588                            mnt);
 589 }
 590
 591 static int jfs_sync_fs(struct super_block *sb, int wait)
 592 {
 593         struct jfs_log *log = JFS_SBI(sb)->log;
 594
 595         /* log == NULL indicates read-only mount */
 596         if (log) {
 597                 jfs_flush_journal(log, wait);
 598                 jfs_syncpt(log, 0);
 599         }
 600
 601         return 0;
 602 }
 603
 604 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 605 {
 606         struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
 607
 608         if (sbi->uid != -1)
 609                 seq_printf(seq, ",uid=%d", sbi->uid);
 610         if (sbi->gid != -1)
 611                 seq_printf(seq, ",gid=%d", sbi->gid);
 612         if (sbi->umask != -1)
 613                 seq_printf(seq, ",umask=%03o", sbi->umask);
 614         if (sbi->flag & JFS_NOINTEGRITY)
 615                 seq_puts(seq, ",nointegrity");
 616         if (sbi->nls_tab)
 617                 seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
 618         if (sbi->flag & JFS_ERR_CONTINUE)
 619                 seq_printf(seq, ",errors=continue");
 620         if (sbi->flag & JFS_ERR_PANIC)
 621                 seq_printf(seq, ",errors=panic");
 622
 623 #ifdef CONFIG_QUOTA
 624         if (sbi->flag & JFS_USRQUOTA)
 625                 seq_puts(seq, ",usrquota");
 626
 627         if (sbi->flag & JFS_GRPQUOTA)
 628                 seq_puts(seq, ",grpquota");
 629 #endif
 630
 631         return 0;
 632 }
 633
 634 #ifdef CONFIG_QUOTA
 635
 636 /* Read data from quotafile - avoid pagecache and such because we cannot afford
 637  * acquiring the locks... As quota files are never truncated and quota code
 638  * itself serializes the operations (and noone else should touch the files)
 639  * we don't have to be afraid of races */
 640 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
 641                               size_t len, loff_t off)
 642 {
 643         struct inode *inode = sb_dqopt(sb)->files[type];
 644         sector_t blk = off >> sb->s_blocksize_bits;
 645         int err = 0;
 646         int offset = off & (sb->s_blocksize - 1);
 647         int tocopy;
 648         size_t toread;
 649         struct buffer_head tmp_bh;
 650         struct buffer_head *bh;
 651         loff_t i_size = i_size_read(inode);
 652
 653         if (off > i_size)
 654                 return 0;
 655         if (off+len > i_size)
 656                 len = i_size-off;
 657         toread = len;
 658         while (toread > 0) {
 659                 tocopy = sb->s_blocksize - offset < toread ?
 660                                 sb->s_blocksize - offset : toread;
 661
 662                 tmp_bh.b_state = 0;
 663                 tmp_bh.b_size = 1 << inode->i_blkbits;
 664                 err = jfs_get_block(inode, blk, &tmp_bh, 0);
 665                 if (err)
 666                         return err;
 667                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
 668                         memset(data, 0, tocopy);
 669                 else {
 670                         bh = sb_bread(sb, tmp_bh.b_blocknr);
 671                         if (!bh)
 672                                 return -EIO;
 673                         memcpy(data, bh->b_data+offset, tocopy);
 674                         brelse(bh);
 675                 }
 676                 offset = 0;
 677                 toread -= tocopy;
 678                 data += tocopy;
 679                 blk++;
 680         }
 681         return len;
 682 }
 683
 684 /* Write to quotafile */
 685 static ssize_t jfs_quota_write(struct super_block *sb, int type,
 686                                const char *data, size_t len, loff_t off)
 687 {
 688         struct inode *inode = sb_dqopt(sb)->files[type];
 689         sector_t blk = off >> sb->s_blocksize_bits;
 690         int err = 0;
 691         int offset = off & (sb->s_blocksize - 1);
 692         int tocopy;
 693         size_t towrite = len;
 694         struct buffer_head tmp_bh;
 695         struct buffer_head *bh;
 696
 697         mutex_lock(&inode->i_mutex);
 698         while (towrite > 0) {
 699                 tocopy = sb->s_blocksize - offset < towrite ?
 700                                 sb->s_blocksize - offset : towrite;
 701
 702                 tmp_bh.b_state = 0;
 703                 tmp_bh.b_size = 1 << inode->i_blkbits;
 704                 err = jfs_get_block(inode, blk, &tmp_bh, 1);
 705                 if (err)
 706                         goto out;
 707                 if (offset || tocopy != sb->s_blocksize)
 708                         bh = sb_bread(sb, tmp_bh.b_blocknr);
 709                 else
 710                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
 711                 if (!bh) {
 712                         err = -EIO;
 713                         goto out;
 714                 }
 715                 lock_buffer(bh);
 716                 memcpy(bh->b_data+offset, data, tocopy);
 717                 flush_dcache_page(bh->b_page);
 718                 set_buffer_uptodate(bh);
 719                 mark_buffer_dirty(bh);
 720                 unlock_buffer(bh);
 721                 brelse(bh);
 722                 offset = 0;
 723                 towrite -= tocopy;
 724                 data += tocopy;
 725                 blk++;
 726         }
 727 out:
 728         if (len == towrite) {
 729                 mutex_unlock(&inode->i_mutex);
 730                 return err;
 731         }
 732         if (inode->i_size < off+len-towrite)
 733                 i_size_write(inode, off+len-towrite);
 734         inode->i_version++;
 735         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 736         mark_inode_dirty(inode);
 737         mutex_unlock(&inode->i_mutex);
 738         return len - towrite;
 739 }
 740
 741 #endif
 742
 743 static const struct super_operations jfs_super_operations = {
 744         .alloc_inode    = jfs_alloc_inode,
 745         .destroy_inode  = jfs_destroy_inode,
 746         .dirty_inode    = jfs_dirty_inode,
 747         .write_inode    = jfs_write_inode,
 748         .delete_inode   = jfs_delete_inode,
 749         .put_super      = jfs_put_super,
 750         .sync_fs        = jfs_sync_fs,
 751         .freeze_fs      = jfs_freeze,
 752         .unfreeze_fs    = jfs_unfreeze,
 753         .statfs         = jfs_statfs,
 754         .remount_fs     = jfs_remount,
 755         .show_options   = jfs_show_options,
 756 #ifdef CONFIG_QUOTA
 757         .quota_read     = jfs_quota_read,
 758         .quota_write    = jfs_quota_write,
 759 #endif
 760 };
 761
 762 static const struct export_operations jfs_export_operations = {
 763         .fh_to_dentry   = jfs_fh_to_dentry,
 764         .fh_to_parent   = jfs_fh_to_parent,
 765         .get_parent     = jfs_get_parent,
 766 };
 767
 768 static struct file_system_type jfs_fs_type = {
 769         .owner          = THIS_MODULE,
 770         .name           = "jfs",
 771         .get_sb         = jfs_get_sb,
 772         .kill_sb        = kill_block_super,
 773         .fs_flags       = FS_REQUIRES_DEV,
 774 };
 775
 776 static void init_once(void *foo)
 777 {
 778         struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
 779
 780         memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
 781         INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
 782         init_rwsem(&jfs_ip->rdwrlock);
 783         mutex_init(&jfs_ip->commit_mutex);
 784         init_rwsem(&jfs_ip->xattr_sem);
 785         spin_lock_init(&jfs_ip->ag_lock);
 786         jfs_ip->active_ag = -1;
 787 #ifdef CONFIG_JFS_POSIX_ACL
 788         jfs_ip->i_acl = JFS_ACL_NOT_CACHED;
 789         jfs_ip->i_default_acl = JFS_ACL_NOT_CACHED;
 790 #endif
 791         inode_init_once(&jfs_ip->vfs_inode);
 792 }
 793
 794 static int __init init_jfs_fs(void)
 795 {
 796         int i;
 797         int rc;
 798
 799         jfs_inode_cachep =
 800             kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
 801                             SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 802                             init_once);
 803         if (jfs_inode_cachep == NULL)
 804                 return -ENOMEM;
 805
 806         /*
 807          * Metapage initialization
 808          */
 809         rc = metapage_init();
 810         if (rc) {
 811                 jfs_err("metapage_init failed w/rc = %d", rc);
 812                 goto free_slab;
 813         }
 814
 815         /*
 816          * Transaction Manager initialization
 817          */
 818         rc = txInit();
 819         if (rc) {
 820                 jfs_err("txInit failed w/rc = %d", rc);
 821                 goto free_metapage;
 822         }
 823
 824         /*
 825          * I/O completion thread (endio)
 826          */
 827         jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
 828         if (IS_ERR(jfsIOthread)) {
 829                 rc = PTR_ERR(jfsIOthread);
 830                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 831                 goto end_txmngr;
 832         }
 833
 834         if (commit_threads < 1)
 835                 commit_threads = num_online_cpus();
 836         if (commit_threads > MAX_COMMIT_THREADS)
 837                 commit_threads = MAX_COMMIT_THREADS;
 838
 839         for (i = 0; i < commit_threads; i++) {
 840                 jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
 841                 if (IS_ERR(jfsCommitThread[i])) {
 842                         rc = PTR_ERR(jfsCommitThread[i]);
 843                         jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 844                         commit_threads = i;
 845                         goto kill_committask;
 846                 }
 847         }
 848
 849         jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
 850         if (IS_ERR(jfsSyncThread)) {
 851                 rc = PTR_ERR(jfsSyncThread);
 852                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 853                 goto kill_committask;
 854         }
 855
 856 #ifdef PROC_FS_JFS
 857         jfs_proc_init();
 858 #endif
 859
 860         return register_filesystem(&jfs_fs_type);
 861
 862 kill_committask:
 863         for (i = 0; i < commit_threads; i++)
 864                 kthread_stop(jfsCommitThread[i]);
 865         kthread_stop(jfsIOthread);
 866 end_txmngr:
 867         txExit();
 868 free_metapage:
 869         metapage_exit();
 870 free_slab:
 871         kmem_cache_destroy(jfs_inode_cachep);
 872         return rc;
 873 }
 874
 875 static void __exit exit_jfs_fs(void)
 876 {
 877         int i;
 878
 879         jfs_info("exit_jfs_fs called");
 880
 881         txExit();
 882         metapage_exit();
 883
 884         kthread_stop(jfsIOthread);
 885         for (i = 0; i < commit_threads; i++)
 886                 kthread_stop(jfsCommitThread[i]);
 887         kthread_stop(jfsSyncThread);
 888 #ifdef PROC_FS_JFS
 889         jfs_proc_clean();
 890 #endif
 891         unregister_filesystem(&jfs_fs_type);
 892         kmem_cache_destroy(jfs_inode_cachep);
 893 }
 894
 895 module_init(init_jfs_fs)
 896 module_exit(exit_jfs_fs)