SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 <linux/slab.h>
  34 #include <asm/uaccess.h>
  35 #include <linux/seq_file.h>
  36 #include <linux/smp_lock.h>
  37
  38 #include "jfs_incore.h"
  39 #include "jfs_filsys.h"
  40 #include "jfs_inode.h"
  41 #include "jfs_metapage.h"
  42 #include "jfs_superblock.h"
  43 #include "jfs_dmap.h"
  44 #include "jfs_imap.h"
  45 #include "jfs_acl.h"
  46 #include "jfs_debug.h"
  47
  48 MODULE_DESCRIPTION("The Journaled Filesystem (JFS)");
  49 MODULE_AUTHOR("Steve Best/Dave Kleikamp/Barry Arndt, IBM");
  50 MODULE_LICENSE("GPL");
  51
  52 static struct kmem_cache * jfs_inode_cachep;
  53
  54 static const struct super_operations jfs_super_operations;
  55 static const struct export_operations jfs_export_operations;
  56 static struct file_system_type jfs_fs_type;
  57
  58 #define MAX_COMMIT_THREADS 64
  59 static int commit_threads = 0;
  60 module_param(commit_threads, int, 0);
  61 MODULE_PARM_DESC(commit_threads, "Number of commit threads");
  62
  63 static struct task_struct *jfsCommitThread[MAX_COMMIT_THREADS];
  64 struct task_struct *jfsIOthread;
  65 struct task_struct *jfsSyncThread;
  66
  67 #ifdef CONFIG_JFS_DEBUG
  68 int jfsloglevel = JFS_LOGLEVEL_WARN;
  69 module_param(jfsloglevel, int, 0644);
  70 MODULE_PARM_DESC(jfsloglevel, "Specify JFS loglevel (0, 1 or 2)");
  71 #endif
  72
  73 static void jfs_handle_error(struct super_block *sb)
  74 {
  75         struct jfs_sb_info *sbi = JFS_SBI(sb);
  76
  77         if (sb->s_flags & MS_RDONLY)
  78                 return;
  79
  80         updateSuper(sb, FM_DIRTY);
  81
  82         if (sbi->flag & JFS_ERR_PANIC)
  83                 panic("JFS (device %s): panic forced after error\n",
  84                         sb->s_id);
  85         else if (sbi->flag & JFS_ERR_REMOUNT_RO) {
  86                 jfs_err("ERROR: (device %s): remounting filesystem "
  87                         "as read-only\n",
  88                         sb->s_id);
  89                 sb->s_flags |= MS_RDONLY;
  90         }
  91
  92         /* nothing is done for continue beyond marking the superblock dirty */
  93 }
  94
  95 void jfs_error(struct super_block *sb, const char * function, ...)
  96 {
  97         static char error_buf[256];
  98         va_list args;
  99
 100         va_start(args, function);
 101         vsnprintf(error_buf, sizeof(error_buf), function, args);
 102         va_end(args);
 103
 104         printk(KERN_ERR "ERROR: (device %s): %s\n", sb->s_id, error_buf);
 105
 106         jfs_handle_error(sb);
 107 }
 108
 109 static struct inode *jfs_alloc_inode(struct super_block *sb)
 110 {
 111         struct jfs_inode_info *jfs_inode;
 112
 113         jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS);
 114         if (!jfs_inode)
 115                 return NULL;
 116         return &jfs_inode->vfs_inode;
 117 }
 118
 119 static void jfs_destroy_inode(struct inode *inode)
 120 {
 121         struct jfs_inode_info *ji = JFS_IP(inode);
 122
 123         BUG_ON(!list_empty(&ji->anon_inode_list));
 124
 125         spin_lock_irq(&ji->ag_lock);
 126         if (ji->active_ag != -1) {
 127                 struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
 128                 atomic_dec(&bmap->db_active[ji->active_ag]);
 129                 ji->active_ag = -1;
 130         }
 131         spin_unlock_irq(&ji->ag_lock);
 132         kmem_cache_free(jfs_inode_cachep, ji);
 133 }
 134
 135 static void jfs_clear_inode(struct inode *inode)
 136 {
 137         dquot_drop(inode);
 138 }
 139
 140 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 141 {
 142         struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
 143         s64 maxinodes;
 144         struct inomap *imap = JFS_IP(sbi->ipimap)->i_imap;
 145
 146         jfs_info("In jfs_statfs");
 147         buf->f_type = JFS_SUPER_MAGIC;
 148         buf->f_bsize = sbi->bsize;
 149         buf->f_blocks = sbi->bmap->db_mapsize;
 150         buf->f_bfree = sbi->bmap->db_nfree;
 151         buf->f_bavail = sbi->bmap->db_nfree;
 152         /*
 153          * If we really return the number of allocated & free inodes, some
 154          * applications will fail because they won't see enough free inodes.
 155          * We'll try to calculate some guess as to how may inodes we can
 156          * really allocate
 157          *
 158          * buf->f_files = atomic_read(&imap->im_numinos);
 159          * buf->f_ffree = atomic_read(&imap->im_numfree);
 160          */
 161         maxinodes = min((s64) atomic_read(&imap->im_numinos) +
 162                         ((sbi->bmap->db_nfree >> imap->im_l2nbperiext)
 163                          << L2INOSPEREXT), (s64) 0xffffffffLL);
 164         buf->f_files = maxinodes;
 165         buf->f_ffree = maxinodes - (atomic_read(&imap->im_numinos) -
 166                                     atomic_read(&imap->im_numfree));
 167         buf->f_fsid.val[0] = (u32)crc32_le(0, sbi->uuid, sizeof(sbi->uuid)/2);
 168         buf->f_fsid.val[1] = (u32)crc32_le(0, sbi->uuid + sizeof(sbi->uuid)/2,
 169                                         sizeof(sbi->uuid)/2);
 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
 182         lock_kernel();
 183
 184         rc = jfs_umount(sb);
 185         if (rc)
 186                 jfs_err("jfs_umount failed with return code %d", rc);
 187
 188         unload_nls(sbi->nls_tab);
 189
 190         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 191         iput(sbi->direct_inode);
 192
 193         kfree(sbi);
 194
 195         unlock_kernel();
 196 }
 197
 198 enum {
 199         Opt_integrity, Opt_nointegrity, Opt_iocharset, Opt_resize,
 200         Opt_resize_nosize, Opt_errors, Opt_ignore, Opt_err, Opt_quota,
 201         Opt_usrquota, Opt_grpquota, Opt_uid, Opt_gid, Opt_umask
 202 };
 203
 204 static const match_table_t tokens = {
 205         {Opt_integrity, "integrity"},
 206         {Opt_nointegrity, "nointegrity"},
 207         {Opt_iocharset, "iocharset=%s"},
 208         {Opt_resize, "resize=%u"},
 209         {Opt_resize_nosize, "resize"},
 210         {Opt_errors, "errors=%s"},
 211         {Opt_ignore, "noquota"},
 212         {Opt_ignore, "quota"},
 213         {Opt_usrquota, "usrquota"},
 214         {Opt_grpquota, "grpquota"},
 215         {Opt_uid, "uid=%u"},
 216         {Opt_gid, "gid=%u"},
 217         {Opt_umask, "umask=%u"},
 218         {Opt_err, NULL}
 219 };
 220
 221 static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
 222                          int *flag)
 223 {
 224         void *nls_map = (void *)-1;     /* -1: no change;  NULL: none */
 225         char *p;
 226         struct jfs_sb_info *sbi = JFS_SBI(sb);
 227
 228         *newLVSize = 0;
 229
 230         if (!options)
 231                 return 1;
 232
 233         while ((p = strsep(&options, ",")) != NULL) {
 234                 substring_t args[MAX_OPT_ARGS];
 235                 int token;
 236                 if (!*p)
 237                         continue;
 238
 239                 token = match_token(p, tokens, args);
 240                 switch (token) {
 241                 case Opt_integrity:
 242                         *flag &= ~JFS_NOINTEGRITY;
 243                         break;
 244                 case Opt_nointegrity:
 245                         *flag |= JFS_NOINTEGRITY;
 246                         break;
 247                 case Opt_ignore:
 248                         /* Silently ignore the quota options */
 249                         /* Don't do anything ;-) */
 250                         break;
 251                 case Opt_iocharset:
 252                         if (nls_map && nls_map != (void *) -1)
 253                                 unload_nls(nls_map);
 254                         if (!strcmp(args[0].from, "none"))
 255                                 nls_map = NULL;
 256                         else {
 257                                 nls_map = load_nls(args[0].from);
 258                                 if (!nls_map) {
 259                                         printk(KERN_ERR
 260                                                "JFS: charset not found\n");
 261                                         goto cleanup;
 262                                 }
 263                         }
 264                         break;
 265                 case Opt_resize:
 266                 {
 267                         char *resize = args[0].from;
 268                         *newLVSize = simple_strtoull(resize, &resize, 0);
 269                         break;
 270                 }
 271                 case Opt_resize_nosize:
 272                 {
 273                         *newLVSize = sb->s_bdev->bd_inode->i_size >>
 274                                 sb->s_blocksize_bits;
 275                         if (*newLVSize == 0)
 276                                 printk(KERN_ERR
 277                                        "JFS: Cannot determine volume size\n");
 278                         break;
 279                 }
 280                 case Opt_errors:
 281                 {
 282                         char *errors = args[0].from;
 283                         if (!errors || !*errors)
 284                                 goto cleanup;
 285                         if (!strcmp(errors, "continue")) {
 286                                 *flag &= ~JFS_ERR_REMOUNT_RO;
 287                                 *flag &= ~JFS_ERR_PANIC;
 288                                 *flag |= JFS_ERR_CONTINUE;
 289                         } else if (!strcmp(errors, "remount-ro")) {
 290                                 *flag &= ~JFS_ERR_CONTINUE;
 291                                 *flag &= ~JFS_ERR_PANIC;
 292                                 *flag |= JFS_ERR_REMOUNT_RO;
 293                         } else if (!strcmp(errors, "panic")) {
 294                                 *flag &= ~JFS_ERR_CONTINUE;
 295                                 *flag &= ~JFS_ERR_REMOUNT_RO;
 296                                 *flag |= JFS_ERR_PANIC;
 297                         } else {
 298                                 printk(KERN_ERR
 299                                        "JFS: %s is an invalid error handler\n",
 300                                        errors);
 301                                 goto cleanup;
 302                         }
 303                         break;
 304                 }
 305
 306 #ifdef CONFIG_QUOTA
 307                 case Opt_quota:
 308                 case Opt_usrquota:
 309                         *flag |= JFS_USRQUOTA;
 310                         break;
 311                 case Opt_grpquota:
 312                         *flag |= JFS_GRPQUOTA;
 313                         break;
 314 #else
 315                 case Opt_usrquota:
 316                 case Opt_grpquota:
 317                 case Opt_quota:
 318                         printk(KERN_ERR
 319                                "JFS: quota operations not supported\n");
 320                         break;
 321 #endif
 322                 case Opt_uid:
 323                 {
 324                         char *uid = args[0].from;
 325                         sbi->uid = simple_strtoul(uid, &uid, 0);
 326                         break;
 327                 }
 328                 case Opt_gid:
 329                 {
 330                         char *gid = args[0].from;
 331                         sbi->gid = simple_strtoul(gid, &gid, 0);
 332                         break;
 333                 }
 334                 case Opt_umask:
 335                 {
 336                         char *umask = args[0].from;
 337                         sbi->umask = simple_strtoul(umask, &umask, 8);
 338                         if (sbi->umask & ~0777) {
 339                                 printk(KERN_ERR
 340                                        "JFS: Invalid value of umask\n");
 341                                 goto cleanup;
 342                         }
 343                         break;
 344                 }
 345                 default:
 346                         printk("jfs: Unrecognized mount option \"%s\" "
 347                                         " or missing value\n", p);
 348                         goto cleanup;
 349                 }
 350         }
 351
 352         if (nls_map != (void *) -1) {
 353                 /* Discard old (if remount) */
 354                 unload_nls(sbi->nls_tab);
 355                 sbi->nls_tab = nls_map;
 356         }
 357         return 1;
 358
 359 cleanup:
 360         if (nls_map && nls_map != (void *) -1)
 361                 unload_nls(nls_map);
 362         return 0;
 363 }
 364
 365 static int jfs_remount(struct super_block *sb, int *flags, char *data)
 366 {
 367         s64 newLVSize = 0;
 368         int rc = 0;
 369         int flag = JFS_SBI(sb)->flag;
 370         int ret;
 371
 372         if (!parse_options(data, sb, &newLVSize, &flag)) {
 373                 return -EINVAL;
 374         }
 375         lock_kernel();
 376         if (newLVSize) {
 377                 if (sb->s_flags & MS_RDONLY) {
 378                         printk(KERN_ERR
 379                   "JFS: resize requires volume to be mounted read-write\n");
 380                         unlock_kernel();
 381                         return -EROFS;
 382                 }
 383                 rc = jfs_extendfs(sb, newLVSize, 0);
 384                 if (rc) {
 385                         unlock_kernel();
 386                         return rc;
 387                 }
 388         }
 389
 390         if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
 391                 /*
 392                  * Invalidate any previously read metadata.  fsck may have
 393                  * changed the on-disk data since we mounted r/o
 394                  */
 395                 truncate_inode_pages(JFS_SBI(sb)->direct_inode->i_mapping, 0);
 396
 397                 JFS_SBI(sb)->flag = flag;
 398                 ret = jfs_mount_rw(sb, 1);
 399                 unlock_kernel();
 400                 return ret;
 401         }
 402         if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY)) {
 403                 rc = jfs_umount_rw(sb);
 404                 JFS_SBI(sb)->flag = flag;
 405                 unlock_kernel();
 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                                 unlock_kernel();
 413                                 return rc;
 414                         }
 415                         JFS_SBI(sb)->flag = flag;
 416                         ret = jfs_mount_rw(sb, 1);
 417                         unlock_kernel();
 418                         return ret;
 419                 }
 420         JFS_SBI(sb)->flag = flag;
 421
 422         unlock_kernel();
 423         return 0;
 424 }
 425
 426 static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 427 {
 428         struct jfs_sb_info *sbi;
 429         struct inode *inode;
 430         int rc;
 431         s64 newLVSize = 0;
 432         int flag, ret = -EINVAL;
 433
 434         jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags);
 435
 436         if (!new_valid_dev(sb->s_bdev->bd_dev))
 437                 return -EOVERFLOW;
 438
 439         sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL);
 440         if (!sbi)
 441                 return -ENOMEM;
 442         sb->s_fs_info = sbi;
 443         sbi->sb = sb;
 444         sbi->uid = sbi->gid = sbi->umask = -1;
 445
 446         /* initialize the mount flag and determine the default error handler */
 447         flag = JFS_ERR_REMOUNT_RO;
 448
 449         if (!parse_options((char *) data, sb, &newLVSize, &flag)) {
 450                 kfree(sbi);
 451                 return -EINVAL;
 452         }
 453         sbi->flag = flag;
 454
 455 #ifdef CONFIG_JFS_POSIX_ACL
 456         sb->s_flags |= MS_POSIXACL;
 457 #endif
 458
 459         if (newLVSize) {
 460                 printk(KERN_ERR "resize option for remount only\n");
 461                 return -EINVAL;
 462         }
 463
 464         /*
 465          * Initialize blocksize to 4K.
 466          */
 467         sb_set_blocksize(sb, PSIZE);
 468
 469         /*
 470          * Set method vectors.
 471          */
 472         sb->s_op = &jfs_super_operations;
 473         sb->s_export_op = &jfs_export_operations;
 474
 475         /*
 476          * Initialize direct-mapping inode/address-space
 477          */
 478         inode = new_inode(sb);
 479         if (inode == NULL) {
 480                 ret = -ENOMEM;
 481                 goto out_kfree;
 482         }
 483         inode->i_ino = 0;
 484         inode->i_nlink = 1;
 485         inode->i_size = sb->s_bdev->bd_inode->i_size;
 486         inode->i_mapping->a_ops = &jfs_metapage_aops;
 487         insert_inode_hash(inode);
 488         mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
 489
 490         sbi->direct_inode = inode;
 491
 492         rc = jfs_mount(sb);
 493         if (rc) {
 494                 if (!silent) {
 495                         jfs_err("jfs_mount failed w/return code = %d", rc);
 496                 }
 497                 goto out_mount_failed;
 498         }
 499         if (sb->s_flags & MS_RDONLY)
 500                 sbi->log = NULL;
 501         else {
 502                 rc = jfs_mount_rw(sb, 0);
 503                 if (rc) {
 504                         if (!silent) {
 505                                 jfs_err("jfs_mount_rw failed, return code = %d",
 506                                         rc);
 507                         }
 508                         goto out_no_rw;
 509                 }
 510         }
 511
 512         sb->s_magic = JFS_SUPER_MAGIC;
 513
 514         inode = jfs_iget(sb, ROOT_I);
 515         if (IS_ERR(inode)) {
 516                 ret = PTR_ERR(inode);
 517                 goto out_no_rw;
 518         }
 519         sb->s_root = d_alloc_root(inode);
 520         if (!sb->s_root)
 521                 goto out_no_root;
 522
 523         if (sbi->mntflag & JFS_OS2)
 524                 sb->s_root->d_op = &jfs_ci_dentry_operations;
 525
 526         /* logical blocks are represented by 40 bits in pxd_t, etc. */
 527         sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
 528 #if BITS_PER_LONG == 32
 529         /*
 530          * Page cache is indexed by long.
 531          * I would use MAX_LFS_FILESIZE, but it's only half as big
 532          */
 533         sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes);
 534 #endif
 535         sb->s_time_gran = 1;
 536         return 0;
 537
 538 out_no_root:
 539         jfs_err("jfs_read_super: get root dentry failed");
 540         iput(inode);
 541
 542 out_no_rw:
 543         rc = jfs_umount(sb);
 544         if (rc) {
 545                 jfs_err("jfs_umount failed with return code %d", rc);
 546         }
 547 out_mount_failed:
 548         filemap_write_and_wait(sbi->direct_inode->i_mapping);
 549         truncate_inode_pages(sbi->direct_inode->i_mapping, 0);
 550         make_bad_inode(sbi->direct_inode);
 551         iput(sbi->direct_inode);
 552         sbi->direct_inode = NULL;
 553 out_kfree:
 554         if (sbi->nls_tab)
 555                 unload_nls(sbi->nls_tab);
 556         kfree(sbi);
 557         return ret;
 558 }
 559
 560 static int jfs_freeze(struct super_block *sb)
 561 {
 562         struct jfs_sb_info *sbi = JFS_SBI(sb);
 563         struct jfs_log *log = sbi->log;
 564
 565         if (!(sb->s_flags & MS_RDONLY)) {
 566                 txQuiesce(sb);
 567                 lmLogShutdown(log);
 568                 updateSuper(sb, FM_CLEAN);
 569         }
 570         return 0;
 571 }
 572
 573 static int jfs_unfreeze(struct super_block *sb)
 574 {
 575         struct jfs_sb_info *sbi = JFS_SBI(sb);
 576         struct jfs_log *log = sbi->log;
 577         int rc = 0;
 578
 579         if (!(sb->s_flags & MS_RDONLY)) {
 580                 updateSuper(sb, FM_MOUNT);
 581                 if ((rc = lmLogInit(log)))
 582                         jfs_err("jfs_unlock failed with return code %d", rc);
 583                 else
 584                         txResume(sb);
 585         }
 586         return 0;
 587 }
 588
 589 static int jfs_get_sb(struct file_system_type *fs_type,
 590         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 591 {
 592         return get_sb_bdev(fs_type, flags, dev_name, data, jfs_fill_super,
 593                            mnt);
 594 }
 595
 596 static int jfs_sync_fs(struct super_block *sb, int wait)
 597 {
 598         struct jfs_log *log = JFS_SBI(sb)->log;
 599
 600         /* log == NULL indicates read-only mount */
 601         if (log) {
 602                 jfs_flush_journal(log, wait);
 603                 jfs_syncpt(log, 0);
 604         }
 605
 606         return 0;
 607 }
 608
 609 static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 610 {
 611         struct jfs_sb_info *sbi = JFS_SBI(vfs->mnt_sb);
 612
 613         if (sbi->uid != -1)
 614                 seq_printf(seq, ",uid=%d", sbi->uid);
 615         if (sbi->gid != -1)
 616                 seq_printf(seq, ",gid=%d", sbi->gid);
 617         if (sbi->umask != -1)
 618                 seq_printf(seq, ",umask=%03o", sbi->umask);
 619         if (sbi->flag & JFS_NOINTEGRITY)
 620                 seq_puts(seq, ",nointegrity");
 621         if (sbi->nls_tab)
 622                 seq_printf(seq, ",iocharset=%s", sbi->nls_tab->charset);
 623         if (sbi->flag & JFS_ERR_CONTINUE)
 624                 seq_printf(seq, ",errors=continue");
 625         if (sbi->flag & JFS_ERR_PANIC)
 626                 seq_printf(seq, ",errors=panic");
 627
 628 #ifdef CONFIG_QUOTA
 629         if (sbi->flag & JFS_USRQUOTA)
 630                 seq_puts(seq, ",usrquota");
 631
 632         if (sbi->flag & JFS_GRPQUOTA)
 633                 seq_puts(seq, ",grpquota");
 634 #endif
 635
 636         return 0;
 637 }
 638
 639 #ifdef CONFIG_QUOTA
 640
 641 /* Read data from quotafile - avoid pagecache and such because we cannot afford
 642  * acquiring the locks... As quota files are never truncated and quota code
 643  * itself serializes the operations (and noone else should touch the files)
 644  * we don't have to be afraid of races */
 645 static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
 646                               size_t len, loff_t off)
 647 {
 648         struct inode *inode = sb_dqopt(sb)->files[type];
 649         sector_t blk = off >> sb->s_blocksize_bits;
 650         int err = 0;
 651         int offset = off & (sb->s_blocksize - 1);
 652         int tocopy;
 653         size_t toread;
 654         struct buffer_head tmp_bh;
 655         struct buffer_head *bh;
 656         loff_t i_size = i_size_read(inode);
 657
 658         if (off > i_size)
 659                 return 0;
 660         if (off+len > i_size)
 661                 len = i_size-off;
 662         toread = len;
 663         while (toread > 0) {
 664                 tocopy = sb->s_blocksize - offset < toread ?
 665                                 sb->s_blocksize - offset : toread;
 666
 667                 tmp_bh.b_state = 0;
 668                 tmp_bh.b_size = 1 << inode->i_blkbits;
 669                 err = jfs_get_block(inode, blk, &tmp_bh, 0);
 670                 if (err)
 671                         return err;
 672                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
 673                         memset(data, 0, tocopy);
 674                 else {
 675                         bh = sb_bread(sb, tmp_bh.b_blocknr);
 676                         if (!bh)
 677                                 return -EIO;
 678                         memcpy(data, bh->b_data+offset, tocopy);
 679                         brelse(bh);
 680                 }
 681                 offset = 0;
 682                 toread -= tocopy;
 683                 data += tocopy;
 684                 blk++;
 685         }
 686         return len;
 687 }
 688
 689 /* Write to quotafile */
 690 static ssize_t jfs_quota_write(struct super_block *sb, int type,
 691                                const char *data, size_t len, loff_t off)
 692 {
 693         struct inode *inode = sb_dqopt(sb)->files[type];
 694         sector_t blk = off >> sb->s_blocksize_bits;
 695         int err = 0;
 696         int offset = off & (sb->s_blocksize - 1);
 697         int tocopy;
 698         size_t towrite = len;
 699         struct buffer_head tmp_bh;
 700         struct buffer_head *bh;
 701
 702         mutex_lock(&inode->i_mutex);
 703         while (towrite > 0) {
 704                 tocopy = sb->s_blocksize - offset < towrite ?
 705                                 sb->s_blocksize - offset : towrite;
 706
 707                 tmp_bh.b_state = 0;
 708                 tmp_bh.b_size = 1 << inode->i_blkbits;
 709                 err = jfs_get_block(inode, blk, &tmp_bh, 1);
 710                 if (err)
 711                         goto out;
 712                 if (offset || tocopy != sb->s_blocksize)
 713                         bh = sb_bread(sb, tmp_bh.b_blocknr);
 714                 else
 715                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
 716                 if (!bh) {
 717                         err = -EIO;
 718                         goto out;
 719                 }
 720                 lock_buffer(bh);
 721                 memcpy(bh->b_data+offset, data, tocopy);
 722                 flush_dcache_page(bh->b_page);
 723                 set_buffer_uptodate(bh);
 724                 mark_buffer_dirty(bh);
 725                 unlock_buffer(bh);
 726                 brelse(bh);
 727                 offset = 0;
 728                 towrite -= tocopy;
 729                 data += tocopy;
 730                 blk++;
 731         }
 732 out:
 733         if (len == towrite) {
 734                 mutex_unlock(&inode->i_mutex);
 735                 return err;
 736         }
 737         if (inode->i_size < off+len-towrite)
 738                 i_size_write(inode, off+len-towrite);
 739         inode->i_version++;
 740         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 741         mark_inode_dirty(inode);
 742         mutex_unlock(&inode->i_mutex);
 743         return len - towrite;
 744 }
 745
 746 #endif
 747
 748 static const struct super_operations jfs_super_operations = {
 749         .alloc_inode    = jfs_alloc_inode,
 750         .destroy_inode  = jfs_destroy_inode,
 751         .dirty_inode    = jfs_dirty_inode,
 752         .write_inode    = jfs_write_inode,
 753         .delete_inode   = jfs_delete_inode,
 754         .clear_inode    = jfs_clear_inode,
 755         .put_super      = jfs_put_super,
 756         .sync_fs        = jfs_sync_fs,
 757         .freeze_fs      = jfs_freeze,
 758         .unfreeze_fs    = jfs_unfreeze,
 759         .statfs         = jfs_statfs,
 760         .remount_fs     = jfs_remount,
 761         .show_options   = jfs_show_options,
 762 #ifdef CONFIG_QUOTA
 763         .quota_read     = jfs_quota_read,
 764         .quota_write    = jfs_quota_write,
 765 #endif
 766 };
 767
 768 static const struct export_operations jfs_export_operations = {
 769         .fh_to_dentry   = jfs_fh_to_dentry,
 770         .fh_to_parent   = jfs_fh_to_parent,
 771         .get_parent     = jfs_get_parent,
 772 };
 773
 774 static struct file_system_type jfs_fs_type = {
 775         .owner          = THIS_MODULE,
 776         .name           = "jfs",
 777         .get_sb         = jfs_get_sb,
 778         .kill_sb        = kill_block_super,
 779         .fs_flags       = FS_REQUIRES_DEV,
 780 };
 781
 782 static void init_once(void *foo)
 783 {
 784         struct jfs_inode_info *jfs_ip = (struct jfs_inode_info *) foo;
 785
 786         memset(jfs_ip, 0, sizeof(struct jfs_inode_info));
 787         INIT_LIST_HEAD(&jfs_ip->anon_inode_list);
 788         init_rwsem(&jfs_ip->rdwrlock);
 789         mutex_init(&jfs_ip->commit_mutex);
 790         init_rwsem(&jfs_ip->xattr_sem);
 791         spin_lock_init(&jfs_ip->ag_lock);
 792         jfs_ip->active_ag = -1;
 793         inode_init_once(&jfs_ip->vfs_inode);
 794 }
 795
 796 static int __init init_jfs_fs(void)
 797 {
 798         int i;
 799         int rc;
 800
 801         jfs_inode_cachep =
 802             kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0,
 803                             SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 804                             init_once);
 805         if (jfs_inode_cachep == NULL)
 806                 return -ENOMEM;
 807
 808         /*
 809          * Metapage initialization
 810          */
 811         rc = metapage_init();
 812         if (rc) {
 813                 jfs_err("metapage_init failed w/rc = %d", rc);
 814                 goto free_slab;
 815         }
 816
 817         /*
 818          * Transaction Manager initialization
 819          */
 820         rc = txInit();
 821         if (rc) {
 822                 jfs_err("txInit failed w/rc = %d", rc);
 823                 goto free_metapage;
 824         }
 825
 826         /*
 827          * I/O completion thread (endio)
 828          */
 829         jfsIOthread = kthread_run(jfsIOWait, NULL, "jfsIO");
 830         if (IS_ERR(jfsIOthread)) {
 831                 rc = PTR_ERR(jfsIOthread);
 832                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 833                 goto end_txmngr;
 834         }
 835
 836         if (commit_threads < 1)
 837                 commit_threads = num_online_cpus();
 838         if (commit_threads > MAX_COMMIT_THREADS)
 839                 commit_threads = MAX_COMMIT_THREADS;
 840
 841         for (i = 0; i < commit_threads; i++) {
 842                 jfsCommitThread[i] = kthread_run(jfs_lazycommit, NULL, "jfsCommit");
 843                 if (IS_ERR(jfsCommitThread[i])) {
 844                         rc = PTR_ERR(jfsCommitThread[i]);
 845                         jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 846                         commit_threads = i;
 847                         goto kill_committask;
 848                 }
 849         }
 850
 851         jfsSyncThread = kthread_run(jfs_sync, NULL, "jfsSync");
 852         if (IS_ERR(jfsSyncThread)) {
 853                 rc = PTR_ERR(jfsSyncThread);
 854                 jfs_err("init_jfs_fs: fork failed w/rc = %d", rc);
 855                 goto kill_committask;
 856         }
 857
 858 #ifdef PROC_FS_JFS
 859         jfs_proc_init();
 860 #endif
 861
 862         return register_filesystem(&jfs_fs_type);
 863
 864 kill_committask:
 865         for (i = 0; i < commit_threads; i++)
 866                 kthread_stop(jfsCommitThread[i]);
 867         kthread_stop(jfsIOthread);
 868 end_txmngr:
 869         txExit();
 870 free_metapage:
 871         metapage_exit();
 872 free_slab:
 873         kmem_cache_destroy(jfs_inode_cachep);
 874         return rc;
 875 }
 876
 877 static void __exit exit_jfs_fs(void)
 878 {
 879         int i;
 880
 881         jfs_info("exit_jfs_fs called");
 882
 883         txExit();
 884         metapage_exit();
 885
 886         kthread_stop(jfsIOthread);
 887         for (i = 0; i < commit_threads; i++)
 888                 kthread_stop(jfsCommitThread[i]);
 889         kthread_stop(jfsSyncThread);
 890 #ifdef PROC_FS_JFS
 891         jfs_proc_clean();
 892 #endif
 893         unregister_filesystem(&jfs_fs_type);
 894         kmem_cache_destroy(jfs_inode_cachep);
 895 }
 896
 897 module_init(init_jfs_fs)
 898 module_exit(exit_jfs_fs)