fs/exofs/super.c

   1 /*
   2  * Copyright (C) 2005, 2006
   3  * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
   4  * Copyright (C) 2005, 2006
   5  * International Business Machines
   6  * Copyright (C) 2008, 2009
   7  * Boaz Harrosh <bharrosh@panasas.com>
   8  *
   9  * Copyrights for code taken from ext2:
  10  *     Copyright (C) 1992, 1993, 1994, 1995
  11  *     Remy Card (card@masi.ibp.fr)
  12  *     Laboratoire MASI - Institut Blaise Pascal
  13  *     Universite Pierre et Marie Curie (Paris VI)
  14  *     from
  15  *     linux/fs/minix/inode.c
  16  *     Copyright (C) 1991, 1992  Linus Torvalds
  17  *
  18  * This file is part of exofs.
  19  *
  20  * exofs is free software; you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation.  Since it is based on ext2, and the only
  23  * valid version of GPL for the Linux kernel is version 2, the only valid
  24  * version of GPL for exofs is version 2.
  25  *
  26  * exofs is distributed in the hope that it will be useful,
  27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29  * GNU General Public License for more details.
  30  *
  31  * You should have received a copy of the GNU General Public License
  32  * along with exofs; if not, write to the Free Software
  33  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  34  */
  35
  36 #include <linux/string.h>
  37 #include <linux/parser.h>
  38 #include <linux/vfs.h>
  39 #include <linux/random.h>
  40 #include <linux/exportfs.h>
  41
  42 #include "exofs.h"
  43
  44 /******************************************************************************
  45  * MOUNT OPTIONS
  46  *****************************************************************************/
  47
  48 /*
  49  * struct to hold what we get from mount options
  50  */
  51 struct exofs_mountopt {
  52         const char *dev_name;
  53         uint64_t pid;
  54         int timeout;
  55 };
  56
  57 /*
  58  * exofs-specific mount-time options.
  59  */
  60 enum { Opt_pid, Opt_to, Opt_mkfs, Opt_format, Opt_err };
  61
  62 /*
  63  * Our mount-time options.  These should ideally be 64-bit unsigned, but the
  64  * kernel's parsing functions do not currently support that.  32-bit should be
  65  * sufficient for most applications now.
  66  */
  67 static match_table_t tokens = {
  68         {Opt_pid, "pid=%u"},
  69         {Opt_to, "to=%u"},
  70         {Opt_err, NULL}
  71 };
  72
  73 /*
  74  * The main option parsing method.  Also makes sure that all of the mandatory
  75  * mount options were set.
  76  */
  77 static int parse_options(char *options, struct exofs_mountopt *opts)
  78 {
  79         char *p;
  80         substring_t args[MAX_OPT_ARGS];
  81         int option;
  82         bool s_pid = false;
  83
  84         EXOFS_DBGMSG("parse_options %s\n", options);
  85         /* defaults */
  86         memset(opts, 0, sizeof(*opts));
  87         opts->timeout = BLK_DEFAULT_SG_TIMEOUT;
  88
  89         while ((p = strsep(&options, ",")) != NULL) {
  90                 int token;
  91                 char str[32];
  92
  93                 if (!*p)
  94                         continue;
  95
  96                 token = match_token(p, tokens, args);
  97                 switch (token) {
  98                 case Opt_pid:
  99                         if (0 == match_strlcpy(str, &args[0], sizeof(str)))
 100                                 return -EINVAL;
 101                         opts->pid = simple_strtoull(str, NULL, 0);
 102                         if (opts->pid < EXOFS_MIN_PID) {
 103                                 EXOFS_ERR("Partition ID must be >= %u",
 104                                           EXOFS_MIN_PID);
 105                                 return -EINVAL;
 106                         }
 107                         s_pid = 1;
 108                         break;
 109                 case Opt_to:
 110                         if (match_int(&args[0], &option))
 111                                 return -EINVAL;
 112                         if (option <= 0) {
 113                                 EXOFS_ERR("Timout must be > 0");
 114                                 return -EINVAL;
 115                         }
 116                         opts->timeout = option * HZ;
 117                         break;
 118                 }
 119         }
 120
 121         if (!s_pid) {
 122                 EXOFS_ERR("Need to specify the following options:\n");
 123                 EXOFS_ERR("    -o pid=pid_no_to_use\n");
 124                 return -EINVAL;
 125         }
 126
 127         return 0;
 128 }
 129
 130 /******************************************************************************
 131  * INODE CACHE
 132  *****************************************************************************/
 133
 134 /*
 135  * Our inode cache.  Isn't it pretty?
 136  */
 137 static struct kmem_cache *exofs_inode_cachep;
 138
 139 /*
 140  * Allocate an inode in the cache
 141  */
 142 static struct inode *exofs_alloc_inode(struct super_block *sb)
 143 {
 144         struct exofs_i_info *oi;
 145
 146         oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL);
 147         if (!oi)
 148                 return NULL;
 149
 150         oi->vfs_inode.i_version = 1;
 151         return &oi->vfs_inode;
 152 }
 153
 154 /*
 155  * Remove an inode from the cache
 156  */
 157 static void exofs_destroy_inode(struct inode *inode)
 158 {
 159         kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
 160 }
 161
 162 /*
 163  * Initialize the inode
 164  */
 165 static void exofs_init_once(void *foo)
 166 {
 167         struct exofs_i_info *oi = foo;
 168
 169         inode_init_once(&oi->vfs_inode);
 170 }
 171
 172 /*
 173  * Create and initialize the inode cache
 174  */
 175 static int init_inodecache(void)
 176 {
 177         exofs_inode_cachep = kmem_cache_create("exofs_inode_cache",
 178                                 sizeof(struct exofs_i_info), 0,
 179                                 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
 180                                 exofs_init_once);
 181         if (exofs_inode_cachep == NULL)
 182                 return -ENOMEM;
 183         return 0;
 184 }
 185
 186 /*
 187  * Destroy the inode cache
 188  */
 189 static void destroy_inodecache(void)
 190 {
 191         kmem_cache_destroy(exofs_inode_cachep);
 192 }
 193
 194 /******************************************************************************
 195  * SUPERBLOCK FUNCTIONS
 196  *****************************************************************************/
 197 static const struct super_operations exofs_sops;
 198 static const struct export_operations exofs_export_ops;
 199
 200 /*
 201  * Write the superblock to the OSD
 202  */
 203 static void exofs_write_super(struct super_block *sb)
 204 {
 205         struct exofs_sb_info *sbi;
 206         struct exofs_fscb *fscb;
 207         struct osd_request *or;
 208         struct osd_obj_id obj;
 209         int ret;
 210
 211         fscb = kzalloc(sizeof(struct exofs_fscb), GFP_KERNEL);
 212         if (!fscb) {
 213                 EXOFS_ERR("exofs_write_super: memory allocation failed.\n");
 214                 return;
 215         }
 216
 217         lock_super(sb);
 218         lock_kernel();
 219         sbi = sb->s_fs_info;
 220         fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
 221         fscb->s_numfiles = cpu_to_le32(sbi->s_numfiles);
 222         fscb->s_magic = cpu_to_le16(sb->s_magic);
 223         fscb->s_newfs = 0;
 224
 225         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
 226         if (unlikely(!or)) {
 227                 EXOFS_ERR("exofs_write_super: osd_start_request failed.\n");
 228                 goto out;
 229         }
 230
 231         obj.partition = sbi->s_pid;
 232         obj.id = EXOFS_SUPER_ID;
 233         ret = osd_req_write_kern(or, &obj, 0, fscb, sizeof(*fscb));
 234         if (unlikely(ret)) {
 235                 EXOFS_ERR("exofs_write_super: osd_req_write_kern failed.\n");
 236                 goto out;
 237         }
 238
 239         ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
 240         if (unlikely(ret)) {
 241                 EXOFS_ERR("exofs_write_super: exofs_sync_op failed.\n");
 242                 goto out;
 243         }
 244         sb->s_dirt = 0;
 245
 246 out:
 247         if (or)
 248                 osd_end_request(or);
 249         unlock_kernel();
 250         unlock_super(sb);
 251         kfree(fscb);
 252 }
 253
 254 /*
 255  * This function is called when the vfs is freeing the superblock.  We just
 256  * need to free our own part.
 257  */
 258 static void exofs_put_super(struct super_block *sb)
 259 {
 260         int num_pend;
 261         struct exofs_sb_info *sbi = sb->s_fs_info;
 262
 263         lock_kernel();
 264
 265         if (sb->s_dirt)
 266                 exofs_write_super(sb);
 267
 268         /* make sure there are no pending commands */
 269         for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;
 270              num_pend = atomic_read(&sbi->s_curr_pending)) {
 271                 wait_queue_head_t wq;
 272                 init_waitqueue_head(&wq);
 273                 wait_event_timeout(wq,
 274                                   (atomic_read(&sbi->s_curr_pending) == 0),
 275                                   msecs_to_jiffies(100));
 276         }
 277
 278         osduld_put_device(sbi->s_dev);
 279         kfree(sb->s_fs_info);
 280         sb->s_fs_info = NULL;
 281
 282         unlock_kernel();
 283 }
 284
 285 /*
 286  * Read the superblock from the OSD and fill in the fields
 287  */
 288 static int exofs_fill_super(struct super_block *sb, void *data, int silent)
 289 {
 290         struct inode *root;
 291         struct exofs_mountopt *opts = data;
 292         struct exofs_sb_info *sbi;      /*extended info                  */
 293         struct exofs_fscb fscb;         /*on-disk superblock info        */
 294         struct osd_request *or = NULL;
 295         struct osd_obj_id obj;
 296         int ret;
 297
 298         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 299         if (!sbi)
 300                 return -ENOMEM;
 301         sb->s_fs_info = sbi;
 302
 303         /* use mount options to fill superblock */
 304         sbi->s_dev = osduld_path_lookup(opts->dev_name);
 305         if (IS_ERR(sbi->s_dev)) {
 306                 ret = PTR_ERR(sbi->s_dev);
 307                 sbi->s_dev = NULL;
 308                 goto free_sbi;
 309         }
 310
 311         sbi->s_pid = opts->pid;
 312         sbi->s_timeout = opts->timeout;
 313
 314         /* fill in some other data by hand */
 315         memset(sb->s_id, 0, sizeof(sb->s_id));
 316         strcpy(sb->s_id, "exofs");
 317         sb->s_blocksize = EXOFS_BLKSIZE;
 318         sb->s_blocksize_bits = EXOFS_BLKSHIFT;
 319         sb->s_maxbytes = MAX_LFS_FILESIZE;
 320         atomic_set(&sbi->s_curr_pending, 0);
 321         sb->s_bdev = NULL;
 322         sb->s_dev = 0;
 323
 324         /* read data from on-disk superblock object */
 325         obj.partition = sbi->s_pid;
 326         obj.id = EXOFS_SUPER_ID;
 327         exofs_make_credential(sbi->s_cred, &obj);
 328
 329         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
 330         if (unlikely(!or)) {
 331                 if (!silent)
 332                         EXOFS_ERR(
 333                                "exofs_fill_super: osd_start_request failed.\n");
 334                 ret = -ENOMEM;
 335                 goto free_sbi;
 336         }
 337         ret = osd_req_read_kern(or, &obj, 0, &fscb, sizeof(fscb));
 338         if (unlikely(ret)) {
 339                 if (!silent)
 340                         EXOFS_ERR(
 341                                "exofs_fill_super: osd_req_read_kern failed.\n");
 342                 ret = -ENOMEM;
 343                 goto free_sbi;
 344         }
 345
 346         ret = exofs_sync_op(or, sbi->s_timeout, sbi->s_cred);
 347         if (unlikely(ret)) {
 348                 if (!silent)
 349                         EXOFS_ERR("exofs_fill_super: exofs_sync_op failed.\n");
 350                 ret = -EIO;
 351                 goto free_sbi;
 352         }
 353
 354         sb->s_magic = le16_to_cpu(fscb.s_magic);
 355         sbi->s_nextid = le64_to_cpu(fscb.s_nextid);
 356         sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
 357
 358         /* make sure what we read from the object store is correct */
 359         if (sb->s_magic != EXOFS_SUPER_MAGIC) {
 360                 if (!silent)
 361                         EXOFS_ERR("ERROR: Bad magic value\n");
 362                 ret = -EINVAL;
 363                 goto free_sbi;
 364         }
 365
 366         /* start generation numbers from a random point */
 367         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 368         spin_lock_init(&sbi->s_next_gen_lock);
 369
 370         /* set up operation vectors */
 371         sb->s_op = &exofs_sops;
 372         sb->s_export_op = &exofs_export_ops;
 373         root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF);
 374         if (IS_ERR(root)) {
 375                 EXOFS_ERR("ERROR: exofs_iget failed\n");
 376                 ret = PTR_ERR(root);
 377                 goto free_sbi;
 378         }
 379         sb->s_root = d_alloc_root(root);
 380         if (!sb->s_root) {
 381                 iput(root);
 382                 EXOFS_ERR("ERROR: get root inode failed\n");
 383                 ret = -ENOMEM;
 384                 goto free_sbi;
 385         }
 386
 387         if (!S_ISDIR(root->i_mode)) {
 388                 dput(sb->s_root);
 389                 sb->s_root = NULL;
 390                 EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n",
 391                        root->i_mode);
 392                 ret = -EINVAL;
 393                 goto free_sbi;
 394         }
 395
 396         ret = 0;
 397 out:
 398         if (or)
 399                 osd_end_request(or);
 400         return ret;
 401
 402 free_sbi:
 403         osduld_put_device(sbi->s_dev); /* NULL safe */
 404         kfree(sbi);
 405         goto out;
 406 }
 407
 408 /*
 409  * Set up the superblock (calls exofs_fill_super eventually)
 410  */
 411 static int exofs_get_sb(struct file_system_type *type,
 412                           int flags, const char *dev_name,
 413                           void *data, struct vfsmount *mnt)
 414 {
 415         struct exofs_mountopt opts;
 416         int ret;
 417
 418         ret = parse_options(data, &opts);
 419         if (ret)
 420                 return ret;
 421
 422         opts.dev_name = dev_name;
 423         return get_sb_nodev(type, flags, &opts, exofs_fill_super, mnt);
 424 }
 425
 426 /*
 427  * Return information about the file system state in the buffer.  This is used
 428  * by the 'df' command, for example.
 429  */
 430 static int exofs_statfs(struct dentry *dentry, struct kstatfs *buf)
 431 {
 432         struct super_block *sb = dentry->d_sb;
 433         struct exofs_sb_info *sbi = sb->s_fs_info;
 434         struct osd_obj_id obj = {sbi->s_pid, 0};
 435         struct osd_attr attrs[] = {
 436                 ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS,
 437                         OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)),
 438                 ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION,
 439                         OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)),
 440         };
 441         uint64_t capacity = ULLONG_MAX;
 442         uint64_t used = ULLONG_MAX;
 443         struct osd_request *or;
 444         uint8_t cred_a[OSD_CAP_LEN];
 445         int ret;
 446
 447         /* get used/capacity attributes */
 448         exofs_make_credential(cred_a, &obj);
 449
 450         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
 451         if (unlikely(!or)) {
 452                 EXOFS_DBGMSG("exofs_statfs: osd_start_request failed.\n");
 453                 return -ENOMEM;
 454         }
 455
 456         osd_req_get_attributes(or, &obj);
 457         osd_req_add_get_attr_list(or, attrs, ARRAY_SIZE(attrs));
 458         ret = exofs_sync_op(or, sbi->s_timeout, cred_a);
 459         if (unlikely(ret))
 460                 goto out;
 461
 462         ret = extract_attr_from_req(or, &attrs[0]);
 463         if (likely(!ret))
 464                 capacity = get_unaligned_be64(attrs[0].val_ptr);
 465         else
 466                 EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n");
 467
 468         ret = extract_attr_from_req(or, &attrs[1]);
 469         if (likely(!ret))
 470                 used = get_unaligned_be64(attrs[1].val_ptr);
 471         else
 472                 EXOFS_DBGMSG("exofs_statfs: get used-space failed.\n");
 473
 474         /* fill in the stats buffer */
 475         buf->f_type = EXOFS_SUPER_MAGIC;
 476         buf->f_bsize = EXOFS_BLKSIZE;
 477         buf->f_blocks = (capacity >> EXOFS_BLKSHIFT);
 478         buf->f_bfree = ((capacity - used) >> EXOFS_BLKSHIFT);
 479         buf->f_bavail = buf->f_bfree;
 480         buf->f_files = sbi->s_numfiles;
 481         buf->f_ffree = EXOFS_MAX_ID - sbi->s_numfiles;
 482         buf->f_namelen = EXOFS_NAME_LEN;
 483
 484 out:
 485         osd_end_request(or);
 486         return ret;
 487 }
 488
 489 static const struct super_operations exofs_sops = {
 490         .alloc_inode    = exofs_alloc_inode,
 491         .destroy_inode  = exofs_destroy_inode,
 492         .write_inode    = exofs_write_inode,
 493         .delete_inode   = exofs_delete_inode,
 494         .put_super      = exofs_put_super,
 495         .write_super    = exofs_write_super,
 496         .statfs         = exofs_statfs,
 497 };
 498
 499 /******************************************************************************
 500  * EXPORT OPERATIONS
 501  *****************************************************************************/
 502
 503 struct dentry *exofs_get_parent(struct dentry *child)
 504 {
 505         unsigned long ino = exofs_parent_ino(child);
 506
 507         if (!ino)
 508                 return NULL;
 509
 510         return d_obtain_alias(exofs_iget(child->d_inode->i_sb, ino));
 511 }
 512
 513 static struct inode *exofs_nfs_get_inode(struct super_block *sb,
 514                 u64 ino, u32 generation)
 515 {
 516         struct inode *inode;
 517
 518         inode = exofs_iget(sb, ino);
 519         if (IS_ERR(inode))
 520                 return ERR_CAST(inode);
 521         if (generation && inode->i_generation != generation) {
 522                 /* we didn't find the right inode.. */
 523                 iput(inode);
 524                 return ERR_PTR(-ESTALE);
 525         }
 526         return inode;
 527 }
 528
 529 static struct dentry *exofs_fh_to_dentry(struct super_block *sb,
 530                                 struct fid *fid, int fh_len, int fh_type)
 531 {
 532         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 533                                     exofs_nfs_get_inode);
 534 }
 535
 536 static struct dentry *exofs_fh_to_parent(struct super_block *sb,
 537                                 struct fid *fid, int fh_len, int fh_type)
 538 {
 539         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 540                                     exofs_nfs_get_inode);
 541 }
 542
 543 static const struct export_operations exofs_export_ops = {
 544         .fh_to_dentry = exofs_fh_to_dentry,
 545         .fh_to_parent = exofs_fh_to_parent,
 546         .get_parent = exofs_get_parent,
 547 };
 548
 549 /******************************************************************************
 550  * INSMOD/RMMOD
 551  *****************************************************************************/
 552
 553 /*
 554  * struct that describes this file system
 555  */
 556 static struct file_system_type exofs_type = {
 557         .owner          = THIS_MODULE,
 558         .name           = "exofs",
 559         .get_sb         = exofs_get_sb,
 560         .kill_sb        = generic_shutdown_super,
 561 };
 562
 563 static int __init init_exofs(void)
 564 {
 565         int err;
 566
 567         err = init_inodecache();
 568         if (err)
 569                 goto out;
 570
 571         err = register_filesystem(&exofs_type);
 572         if (err)
 573                 goto out_d;
 574
 575         return 0;
 576 out_d:
 577         destroy_inodecache();
 578 out:
 579         return err;
 580 }
 581
 582 static void __exit exit_exofs(void)
 583 {
 584         unregister_filesystem(&exofs_type);
 585         destroy_inodecache();
 586 }
 587
 588 MODULE_AUTHOR("Avishay Traeger <avishay@gmail.com>");
 589 MODULE_DESCRIPTION("exofs");
 590 MODULE_LICENSE("GPL");
 591
 592 module_init(init_exofs)
 593 module_exit(exit_exofs)