lustre/obdfs/super.c

   1 /*
   2  * OBDFS Super operations
   3  *
   4  * Copryright (C) 1996 Peter J. Braam <braam@stelias.com>
   5  * Copryright (C) 1999 Stelias Computing Inc. <braam@stelias.com>
   6  * Copryright (C) 1999 Seagate Technology Inc.
   7  * Copryright (C) 2001 Mountain View Data, Inc.
   8  *
   9  */
  10
  11 #define EXPORT_SYMTAB
  12
  13 #include <linux/config.h>
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/mm.h>
  17 #include <linux/string.h>
  18 #include <linux/stat.h>
  19 #include <linux/errno.h>
  20 #include <linux/locks.h>
  21 #include <linux/unistd.h>
  22
  23 #include <asm/system.h>
  24 #include <asm/uaccess.h>
  25
  26 #include <linux/fs.h>
  27 #include <linux/stat.h>
  28 #include <asm/uaccess.h>
  29 #include <linux/vmalloc.h>
  30 #include <asm/segment.h>
  31
  32 #include <linux/obd_support.h>
  33 #include <linux/obd_class.h>
  34 #include <linux/obdfs.h>
  35
  36 struct list_head obdfs_super_list;
  37 struct address_space_operations obdfs_aops;
  38 struct super_operations obdfs_super_operations;
  39 long obdfs_cache_count = 0;
  40 long obdfs_mutex_start = 0;
  41 long obd_memory = 0;
  42
  43 static char *obdfs_read_opt(const char *opt, char *data)
  44 {
  45         char *value;
  46         char *retval;
  47
  48         CDEBUG(D_INFO, "option: %s, data %s\n", opt, data);
  49         if ( strncmp(opt, data, strlen(opt)) )
  50                 return NULL;
  51
  52         if ( (value = strchr(data, '=')) == NULL )
  53                 return NULL;
  54
  55         value++;
  56         OBD_ALLOC(retval, char *, strlen(value) + 1);
  57         if ( !retval ) {
  58                 printk(KERN_ALERT __FUNCTION__ ": out of memory!\n");
  59                 return NULL;
  60         }
  61
  62         memcpy(retval, value, strlen(value)+1);
  63         CDEBUG(D_PSDEV, "Assigned option: %s, value %s\n", opt, retval);
  64         return retval;
  65 }
  66
  67 static void obdfs_options(char *options, char **dev, char **vers)
  68 {
  69         char *this_char;
  70
  71         if (!options)
  72                 return;
  73
  74         for (this_char = strtok (options, ",");
  75              this_char != NULL;
  76              this_char = strtok (NULL, ",")) {
  77                 CDEBUG(D_INFO, "this_char %s\n", this_char);
  78                 if ( (!*dev && (*dev = obdfs_read_opt("device", this_char)))||
  79                      (!*vers && (*vers = obdfs_read_opt("version", this_char))) )
  80                         continue;
  81
  82         }
  83 }
  84
  85 static int obdfs_getdev(char *devpath, int *dev)
  86 {
  87         struct dentry *dentry;
  88         kdev_t devno;
  89         struct nameidata nd;
  90         int error = 0;
  91
  92         ENTRY;
  93         if (path_init(devpath, LOOKUP_POSITIVE, &nd))
  94                 error = path_walk(devpath, &nd);
  95         if (error)
  96                 return error;
  97
  98         dentry = nd.dentry;
  99         if (!S_ISCHR(dentry->d_inode->i_mode))
 100                 return -ENODEV;
 101
 102         devno = dentry->d_inode->i_rdev;
 103         if ( MAJOR(devno) != OBD_PSDEV_MAJOR )
 104                 return -ENODEV;
 105
 106         if ( MINOR(devno) >= MAX_OBD_DEVICES )
 107                 return -ENODEV;
 108
 109         *dev = devno;
 110         return 0;
 111 }
 112
 113
 114 static struct super_block * obdfs_read_super(struct super_block *sb,
 115                                             void *data, int silent)
 116 {
 117         struct inode *root = 0;
 118         struct obdfs_sb_info *sbi = (struct obdfs_sb_info *)(&sb->u.generic_sbp);
 119         struct obd_device *obddev;
 120         char *device = NULL;
 121         char *version = NULL;
 122         int devno;
 123         int err;
 124         unsigned long blocksize;
 125         unsigned long blocksize_bits;
 126         unsigned long root_ino;
 127         int scratch;
 128
 129
 130         ENTRY;
 131         MOD_INC_USE_COUNT;
 132
 133         memset(sbi, 0, sizeof(*sbi));
 134
 135         CDEBUG(D_INFO, "\n");
 136         obdfs_options(data, &device, &version);
 137         if ( !device ) {
 138                 printk(__FUNCTION__ ": no device\n");
 139                 EXIT;
 140                 goto ERR;
 141         }
 142
 143         CDEBUG(D_INFO, "\n");
 144         if ( (err = obdfs_getdev(device, &devno)) ) {
 145                 printk("Cannot get devno of %s, error %d\n", device, err);
 146                 EXIT;
 147                 goto ERR;;
 148         }
 149
 150         CDEBUG(D_INFO, "\n");
 151         if ( MAJOR(devno) != OBD_PSDEV_MAJOR ) {
 152                 printk(__FUNCTION__ ": wrong major number %d!\n", MAJOR(devno));
 153                 EXIT;
 154                 goto ERR;
 155         }
 156
 157         CDEBUG(D_INFO, "\n");
 158         if ( MINOR(devno) >= MAX_OBD_DEVICES ) {
 159                 printk(__FUNCTION__ ": minor of %s too high (%d)\n",
 160                        device, MINOR(devno));
 161                 EXIT;
 162                 goto ERR;
 163         }
 164
 165         CDEBUG(D_INFO, "\n");
 166         obddev = &obd_dev[MINOR(devno)];
 167
 168         CDEBUG(D_INFO, "\n");
 169         if ( ! (obddev->obd_flags & OBD_ATTACHED) ||
 170              ! (obddev->obd_flags & OBD_SET_UP) ){
 171                 printk("device %s not attached or not set up (%d)\n",
 172                        device, MINOR(devno));
 173                 EXIT;
 174                 goto ERR;;
 175         }
 176
 177         CDEBUG(D_INFO, "\n");
 178         sbi->osi_obd = obddev;
 179         sbi->osi_ops = sbi->osi_obd->obd_type->typ_ops;
 180
 181         sbi->osi_conn.oc_dev = obddev;
 182         err = sbi->osi_ops->o_connect(&sbi->osi_conn);
 183         if ( err ) {
 184                 printk("OBDFS: cannot connect to %s\n", device);
 185                 EXIT;
 186                 goto ERR;
 187         }
 188
 189         CDEBUG(D_INFO, "\n");
 190         /* list of dirty inodes, and a mutex to hold while modifying it */
 191         INIT_LIST_HEAD(&sbi->osi_inodes);
 192         sema_init(&sbi->osi_list_mutex, 1);
 193
 194         CDEBUG(D_INFO, "\n");
 195         sbi->osi_super = sb;
 196
 197         CDEBUG(D_INFO, "\n");
 198         err = sbi->osi_ops->o_get_info(&sbi->osi_conn, strlen("blocksize"),
 199                                        "blocksize", &scratch,
 200                                        (void *)&blocksize);
 201         if ( err ) {
 202                 printk("getinfo call to drive failed (blocksize)\n");
 203                 EXIT;
 204                 goto ERR;
 205         }
 206
 207         CDEBUG(D_INFO, "\n");
 208         err = sbi->osi_ops->o_get_info(&sbi->osi_conn, strlen("blocksize_bits"),
 209                                        "blocksize_bits", &scratch,
 210                                        (void *)&blocksize_bits);
 211         if ( err ) {
 212                 printk("getinfo call to drive failed (blocksize_bits)\n");
 213                 EXIT;
 214                 goto ERR;
 215         }
 216
 217         CDEBUG(D_INFO, "\n");
 218         err = sbi->osi_ops->o_get_info(&sbi->osi_conn, strlen("root_ino"),
 219                                        "root_ino", &scratch, (void *)&root_ino);
 220         if ( err ) {
 221                 printk("getinfo call to drive failed (root_ino)\n");
 222                 EXIT;
 223                 goto ERR;
 224         }
 225
 226         CDEBUG(D_INFO, "\n");
 227         sb->s_blocksize = blocksize;
 228         sb->s_blocksize_bits = (unsigned char)blocksize_bits;
 229         sb->s_magic = OBDFS_SUPER_MAGIC;
 230         sb->s_op = &obdfs_super_operations;
 231
 232         /* XXX how to get "sb->s_flags |= MS_RDONLY" here for snapshots? */
 233
 234         /* make root inode */
 235         CDEBUG(D_INFO, "\n");
 236         root = iget(sb, root_ino);
 237         if (!root || is_bad_inode(root)) {
 238             printk("OBDFS: bad iget for root\n");
 239             sb->s_dev = 0;
 240             err = -ENOENT;
 241             EXIT;
 242             goto ERR;
 243         }
 244
 245         CDEBUG(D_INFO, "obdfs_read_super: sbdev %d, rootino: %ld, dev %s, "
 246                "minor: %d, blocksize: %ld, blocksize bits %ld\n",
 247                sb->s_dev, root->i_ino, device, MINOR(devno),
 248                blocksize, blocksize_bits);
 249         sb->s_root = d_alloc_root(root);
 250         list_add(&sbi->osi_list, &obdfs_super_list);
 251         OBD_FREE(device, strlen(device) + 1);
 252         if (version)
 253                 OBD_FREE(version, strlen(version) + 1);
 254         EXIT;
 255         return sb;
 256
 257 ERR:
 258         MOD_DEC_USE_COUNT;
 259         if (device)
 260                 OBD_FREE(device, strlen(device) + 1);
 261         if (version)
 262                 OBD_FREE(version, strlen(version) + 1);
 263         if (sbi) {
 264                 sbi->osi_super = NULL;
 265         }
 266         if (root) {
 267                 iput(root);
 268         }
 269         sb->s_dev = 0;
 270         return NULL;
 271 } /* obdfs_read_super */
 272
 273
 274 static void obdfs_put_super(struct super_block *sb)
 275 {
 276         struct obdfs_sb_info *sbi;
 277
 278         ENTRY;
 279         sb->s_dev = 0;
 280
 281         sbi = (struct obdfs_sb_info *) &sb->u.generic_sbp;
 282         obdfs_flush_reqs(&sbi->osi_inodes, ~0UL);
 283
 284         OPS(sb,disconnect)(ID(sb));
 285         list_del(&sbi->osi_list);
 286         memset(sbi, 0, sizeof(*sbi));
 287
 288         printk(KERN_INFO "OBDFS: Bye bye.\n");
 289
 290         MOD_DEC_USE_COUNT;
 291         EXIT;
 292 } /* obdfs_put_super */
 293
 294
 295 /* all filling in of inodes postponed until lookup */
 296 static void obdfs_read_inode(struct inode *inode)
 297 {
 298         struct obdo *oa;
 299         ENTRY;
 300         oa = obdo_fromid(IID(inode), inode->i_ino,
 301                          OBD_MD_FLNOTOBD | OBD_MD_FLBLOCKS);
 302         if ( IS_ERR(oa) ) {
 303                 printk(__FUNCTION__ ": obdo_fromid failed\n");
 304                 EXIT;
 305                 return /* PTR_ERR(oa) */;
 306         }
 307
 308         ODEBUG(oa);
 309         obdfs_to_inode(inode, oa);
 310         INIT_LIST_HEAD(obdfs_iplist(inode)); /* list of dirty pages on inode */
 311         INIT_LIST_HEAD(obdfs_islist(inode)); /* list of inodes in superblock */
 312
 313         obdo_free(oa);
 314         /* OIDEBUG(inode); */
 315
 316         if (S_ISREG(inode->i_mode)) {
 317                 inode->i_op = &obdfs_file_inode_operations;
 318                 inode->i_fop = &obdfs_file_operations;
 319                 inode->i_mapping->a_ops = &obdfs_aops;
 320                 EXIT;
 321         } else if (S_ISDIR(inode->i_mode)) {
 322                 inode->i_op = &obdfs_dir_inode_operations;
 323                 inode->i_fop = &obdfs_dir_operations;
 324                 EXIT;
 325         } else if (S_ISLNK(inode->i_mode)) {
 326                 if (inode->i_blocks) {
 327                         inode->i_op = &obdfs_symlink_inode_operations;
 328                         inode->i_mapping->a_ops = &obdfs_aops;
 329                 }else {
 330                         inode->i_op = &obdfs_fast_symlink_inode_operations;
 331                 }
 332                 EXIT;
 333         } else {
 334                 init_special_inode(inode, inode->i_mode,
 335                                    ((int *)obdfs_i2info(inode)->oi_inline)[0]);
 336         }
 337
 338         return;
 339 }
 340
 341 static void obdfs_write_inode(struct inode *inode, int wait)
 342 {
 343         struct obdo *oa;
 344         int err;
 345
 346         ENTRY;
 347         if (IOPS(inode, setattr) == NULL) {
 348                 printk(KERN_ERR __FUNCTION__ ": no setattr method!\n");
 349                 EXIT;
 350                 return;
 351         }
 352         oa = obdo_alloc();
 353         if ( !oa ) {
 354                 printk(__FUNCTION__ ": obdo_alloc failed\n");
 355                 EXIT;
 356                 return;
 357         }
 358
 359         oa->o_valid = OBD_MD_FLNOTOBD;
 360         obdfs_from_inode(oa, inode);
 361         err = IOPS(inode, setattr)(IID(inode), oa);
 362
 363         if ( err )
 364                 printk(__FUNCTION__ ": obd_setattr fails (%d)\n", err);
 365
 366         EXIT;
 367         obdo_free(oa);
 368 } /* obdfs_write_inode */
 369
 370
 371 /* This routine is called from iput() (for each unlink on the inode).
 372  * We can't put this call into delete_inode() since that is called only
 373  * when i_count == 0, and we need to keep a reference on the inode while
 374  * it is in the page cache, which means i_count > 0.  Catch 22.
 375  */
 376 static void obdfs_put_inode(struct inode *inode)
 377 {
 378         ENTRY;
 379         if (inode->i_nlink) {
 380                 EXIT;
 381                 return;
 382         }
 383
 384         obdfs_dequeue_pages(inode);
 385         EXIT;
 386 } /* obdfs_put_inode */
 387
 388
 389 static void obdfs_delete_inode(struct inode *inode)
 390 {
 391         struct obdo *oa;
 392         int err;
 393
 394         ENTRY;
 395         if (IOPS(inode, destroy) == NULL) {
 396                 printk(KERN_ERR __FUNCTION__ ": no destroy method!\n");
 397                 EXIT;
 398                 return;
 399         }
 400
 401         oa = obdo_alloc();
 402         if ( !oa ) {
 403                 printk(__FUNCTION__ ": obdo_alloc failed\n");
 404                 EXIT;
 405                 return;
 406         }
 407         oa->o_valid = OBD_MD_FLNOTOBD;
 408         obdfs_from_inode(oa, inode);
 409
 410         ODEBUG(oa);
 411         err = IOPS(inode, destroy)(IID(inode), oa);
 412         obdo_free(oa);
 413         clear_inode(inode);
 414         if (err) {
 415                 printk(__FUNCTION__ ": obd_destroy fails (%d)\n", err);
 416                 EXIT;
 417                 return;
 418         }
 419
 420         EXIT;
 421 } /* obdfs_delete_inode */
 422
 423
 424 int obdfs_notify_change(struct dentry *de, struct iattr *attr)
 425 {
 426         struct inode *inode = de->d_inode;
 427         struct obdo *oa;
 428         int err;
 429
 430         ENTRY;
 431         if (IOPS(inode, setattr) == NULL) {
 432                 printk(KERN_ERR __FUNCTION__ ": no setattr method!\n");
 433                 EXIT;
 434                 return -EIO;
 435         }
 436         oa = obdo_alloc();
 437         if ( !oa ) {
 438                 printk(__FUNCTION__ ": obdo_alloc failed\n");
 439                 return -ENOMEM;
 440         }
 441
 442         oa->o_id = inode->i_ino;
 443         obdo_from_iattr(oa, attr);
 444         err = IOPS(inode, setattr)(IID(inode), oa);
 445
 446         if ( err )
 447                 printk(__FUNCTION__ ": obd_setattr fails (%d)\n", err);
 448
 449         EXIT;
 450         obdo_free(oa);
 451         return err;
 452 } /* obdfs_notify_change */
 453
 454
 455 static int obdfs_statfs(struct super_block *sb, struct statfs *buf)
 456 {
 457         struct statfs tmp;
 458         int bufsize = sizeof(*buf);
 459         int err;
 460
 461         ENTRY;
 462
 463         err = OPS(sb,statfs)(ID(sb), &tmp);
 464         if ( err ) {
 465                 printk(__FUNCTION__ ": obd_statfs fails (%d)\n", err);
 466                 return err;
 467         }
 468         copy_to_user(buf, &tmp, (bufsize<sizeof(tmp)) ? bufsize : sizeof(tmp));
 469
 470         EXIT;
 471
 472         return err;
 473 }
 474
 475 /* exported operations */
 476 struct super_operations obdfs_super_operations =
 477 {
 478         read_inode: obdfs_read_inode,
 479         write_inode: obdfs_write_inode,
 480         put_inode: obdfs_put_inode,
 481         delete_inode: obdfs_delete_inode,
 482         put_super: obdfs_put_super,
 483         statfs: obdfs_statfs
 484 };
 485
 486 struct file_system_type obdfs_fs_type = {
 487    "obdfs", 0, obdfs_read_super, NULL
 488 };
 489
 490 int init_obdfs(void)
 491 {
 492         int err;
 493
 494         printk(KERN_INFO "OBDFS v0.1, braam@stelias.com\n");
 495
 496         obdfs_sysctl_init();
 497
 498         INIT_LIST_HEAD(&obdfs_super_list);
 499         err = obdfs_init_pgrqcache();
 500         if (err)
 501                 return err;
 502
 503         obdfs_flushd_init();
 504         return register_filesystem(&obdfs_fs_type);
 505 }
 506
 507 struct address_space_operations obdfs_aops = {
 508         readpage: obdfs_readpage,
 509         writepage: obdfs_writepage,
 510         sync_page: block_sync_page,
 511         prepare_write: obdfs_prepare_write,
 512         commit_write: obdfs_commit_write,
 513         bmap: NULL
 514 };
 515
 516
 517 #ifdef MODULE
 518 int init_module(void)
 519 {
 520         return init_obdfs();
 521 }
 522
 523 void cleanup_module(void)
 524 {
 525         ENTRY;
 526
 527         obdfs_flushd_cleanup();
 528         obdfs_sysctl_clean();
 529         obdfs_cleanup_pgrqcache();
 530         unregister_filesystem(&obdfs_fs_type);
 531         CDEBUG(D_MALLOC, "OBDFS mem used %ld\n", obd_memory);
 532         EXIT;
 533 }
 534
 535 #endif