fs/fuse/inode.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU GPL.
   6   See the file COPYING.
   7 */
   8
   9 #include "fuse_i.h"
  10
  11 #include <linux/pagemap.h>
  12 #include <linux/slab.h>
  13 #include <linux/file.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/moduleparam.h>
  18 #include <linux/parser.h>
  19 #include <linux/statfs.h>
  20 #include <linux/random.h>
  21 #include <linux/sched.h>
  22 #include <linux/exportfs.h>
  23 #include <linux/posix_acl.h>
  24
  25 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  26 MODULE_DESCRIPTION("Filesystem in Userspace");
  27 MODULE_LICENSE("GPL");
  28
  29 static struct kmem_cache *fuse_inode_cachep;
  30 struct list_head fuse_conn_list;
  31 DEFINE_MUTEX(fuse_mutex);
  32
  33 static int set_global_limit(const char *val, struct kernel_param *kp);
  34
  35 unsigned max_user_bgreq;
  36 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
  37                   &max_user_bgreq, 0644);
  38 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
  39 MODULE_PARM_DESC(max_user_bgreq,
  40  "Global limit for the maximum number of backgrounded requests an "
  41  "unprivileged user can set");
  42
  43 unsigned max_user_congthresh;
  44 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
  45                   &max_user_congthresh, 0644);
  46 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
  47 MODULE_PARM_DESC(max_user_congthresh,
  48  "Global limit for the maximum congestion threshold an "
  49  "unprivileged user can set");
  50
  51 #define FUSE_SUPER_MAGIC 0x65735546
  52
  53 #define FUSE_DEFAULT_BLKSIZE 512
  54
  55 /** Maximum number of outstanding background requests */
  56 #define FUSE_DEFAULT_MAX_BACKGROUND 12
  57
  58 /** Congestion starts at 75% of maximum */
  59 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
  60
  61 struct fuse_mount_data {
  62         int fd;
  63         unsigned rootmode;
  64         kuid_t user_id;
  65         kgid_t group_id;
  66         unsigned fd_present:1;
  67         unsigned rootmode_present:1;
  68         unsigned user_id_present:1;
  69         unsigned group_id_present:1;
  70         unsigned default_permissions:1;
  71         unsigned allow_other:1;
  72         unsigned max_read;
  73         unsigned blksize;
  74 };
  75
  76 struct fuse_forget_link *fuse_alloc_forget(void)
  77 {
  78         return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
  79 }
  80
  81 static struct inode *fuse_alloc_inode(struct super_block *sb)
  82 {
  83         struct inode *inode;
  84         struct fuse_inode *fi;
  85
  86         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  87         if (!inode)
  88                 return NULL;
  89
  90         fi = get_fuse_inode(inode);
  91         fi->i_time = 0;
  92         fi->nodeid = 0;
  93         fi->nlookup = 0;
  94         fi->attr_version = 0;
  95         fi->writectr = 0;
  96         fi->orig_ino = 0;
  97         fi->state = 0;
  98         INIT_LIST_HEAD(&fi->write_files);
  99         INIT_LIST_HEAD(&fi->queued_writes);
 100         INIT_LIST_HEAD(&fi->writepages);
 101         init_waitqueue_head(&fi->page_waitq);
 102         mutex_init(&fi->mutex);
 103         fi->forget = fuse_alloc_forget();
 104         if (!fi->forget) {
 105                 kmem_cache_free(fuse_inode_cachep, inode);
 106                 return NULL;
 107         }
 108
 109         return inode;
 110 }
 111
 112 static void fuse_i_callback(struct rcu_head *head)
 113 {
 114         struct inode *inode = container_of(head, struct inode, i_rcu);
 115         kmem_cache_free(fuse_inode_cachep, inode);
 116 }
 117
 118 static void fuse_destroy_inode(struct inode *inode)
 119 {
 120         struct fuse_inode *fi = get_fuse_inode(inode);
 121         BUG_ON(!list_empty(&fi->write_files));
 122         BUG_ON(!list_empty(&fi->queued_writes));
 123         mutex_destroy(&fi->mutex);
 124         kfree(fi->forget);
 125         call_rcu(&inode->i_rcu, fuse_i_callback);
 126 }
 127
 128 static void fuse_evict_inode(struct inode *inode)
 129 {
 130         truncate_inode_pages_final(&inode->i_data);
 131         clear_inode(inode);
 132         if (inode->i_sb->s_flags & MS_ACTIVE) {
 133                 struct fuse_conn *fc = get_fuse_conn(inode);
 134                 struct fuse_inode *fi = get_fuse_inode(inode);
 135                 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
 136                 fi->forget = NULL;
 137         }
 138 }
 139
 140 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 141 {
 142         sync_filesystem(sb);
 143         if (*flags & MS_MANDLOCK)
 144                 return -EINVAL;
 145
 146         return 0;
 147 }
 148
 149 /*
 150  * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
 151  * so that it will fit.
 152  */
 153 static ino_t fuse_squash_ino(u64 ino64)
 154 {
 155         ino_t ino = (ino_t) ino64;
 156         if (sizeof(ino_t) < sizeof(u64))
 157                 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
 158         return ino;
 159 }
 160
 161 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 162                                    u64 attr_valid)
 163 {
 164         struct fuse_conn *fc = get_fuse_conn(inode);
 165         struct fuse_inode *fi = get_fuse_inode(inode);
 166
 167         fi->attr_version = ++fc->attr_version;
 168         fi->i_time = attr_valid;
 169
 170         inode->i_ino     = fuse_squash_ino(attr->ino);
 171         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 172         set_nlink(inode, attr->nlink);
 173         inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
 174         inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
 175         inode->i_blocks  = attr->blocks;
 176         inode->i_atime.tv_sec   = attr->atime;
 177         inode->i_atime.tv_nsec  = attr->atimensec;
 178         /* mtime from server may be stale due to local buffered write */
 179         if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
 180                 inode->i_mtime.tv_sec   = attr->mtime;
 181                 inode->i_mtime.tv_nsec  = attr->mtimensec;
 182                 inode->i_ctime.tv_sec   = attr->ctime;
 183                 inode->i_ctime.tv_nsec  = attr->ctimensec;
 184         }
 185
 186         if (attr->blksize != 0)
 187                 inode->i_blkbits = ilog2(attr->blksize);
 188         else
 189                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 190
 191         /*
 192          * Don't set the sticky bit in i_mode, unless we want the VFS
 193          * to check permissions.  This prevents failures due to the
 194          * check in may_delete().
 195          */
 196         fi->orig_i_mode = inode->i_mode;
 197         if (!fc->default_permissions)
 198                 inode->i_mode &= ~S_ISVTX;
 199
 200         fi->orig_ino = attr->ino;
 201 }
 202
 203 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 204                             u64 attr_valid, u64 attr_version)
 205 {
 206         struct fuse_conn *fc = get_fuse_conn(inode);
 207         struct fuse_inode *fi = get_fuse_inode(inode);
 208         bool is_wb = fc->writeback_cache;
 209         loff_t oldsize;
 210         struct timespec old_mtime;
 211
 212         spin_lock(&fc->lock);
 213         if ((attr_version != 0 && fi->attr_version > attr_version) ||
 214             test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
 215                 spin_unlock(&fc->lock);
 216                 return;
 217         }
 218
 219         old_mtime = inode->i_mtime;
 220         fuse_change_attributes_common(inode, attr, attr_valid);
 221
 222         oldsize = inode->i_size;
 223         /*
 224          * In case of writeback_cache enabled, the cached writes beyond EOF
 225          * extend local i_size without keeping userspace server in sync. So,
 226          * attr->size coming from server can be stale. We cannot trust it.
 227          */
 228         if (!is_wb || !S_ISREG(inode->i_mode))
 229                 i_size_write(inode, attr->size);
 230         spin_unlock(&fc->lock);
 231
 232         if (!is_wb && S_ISREG(inode->i_mode)) {
 233                 bool inval = false;
 234
 235                 if (oldsize != attr->size) {
 236                         truncate_pagecache(inode, attr->size);
 237                         inval = true;
 238                 } else if (fc->auto_inval_data) {
 239                         struct timespec new_mtime = {
 240                                 .tv_sec = attr->mtime,
 241                                 .tv_nsec = attr->mtimensec,
 242                         };
 243
 244                         /*
 245                          * Auto inval mode also checks and invalidates if mtime
 246                          * has changed.
 247                          */
 248                         if (!timespec_equal(&old_mtime, &new_mtime))
 249                                 inval = true;
 250                 }
 251
 252                 if (inval)
 253                         invalidate_inode_pages2(inode->i_mapping);
 254         }
 255 }
 256
 257 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 258 {
 259         inode->i_mode = attr->mode & S_IFMT;
 260         inode->i_size = attr->size;
 261         inode->i_mtime.tv_sec  = attr->mtime;
 262         inode->i_mtime.tv_nsec = attr->mtimensec;
 263         inode->i_ctime.tv_sec  = attr->ctime;
 264         inode->i_ctime.tv_nsec = attr->ctimensec;
 265         if (S_ISREG(inode->i_mode)) {
 266                 fuse_init_common(inode);
 267                 fuse_init_file_inode(inode);
 268         } else if (S_ISDIR(inode->i_mode))
 269                 fuse_init_dir(inode);
 270         else if (S_ISLNK(inode->i_mode))
 271                 fuse_init_symlink(inode);
 272         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 273                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 274                 fuse_init_common(inode);
 275                 init_special_inode(inode, inode->i_mode,
 276                                    new_decode_dev(attr->rdev));
 277         } else
 278                 BUG();
 279 }
 280
 281 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 282 {
 283         u64 nodeid = *(u64 *) _nodeidp;
 284         if (get_node_id(inode) == nodeid)
 285                 return 1;
 286         else
 287                 return 0;
 288 }
 289
 290 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 291 {
 292         u64 nodeid = *(u64 *) _nodeidp;
 293         get_fuse_inode(inode)->nodeid = nodeid;
 294         return 0;
 295 }
 296
 297 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 298                         int generation, struct fuse_attr *attr,
 299                         u64 attr_valid, u64 attr_version)
 300 {
 301         struct inode *inode;
 302         struct fuse_inode *fi;
 303         struct fuse_conn *fc = get_fuse_conn_super(sb);
 304
 305  retry:
 306         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 307         if (!inode)
 308                 return NULL;
 309
 310         if ((inode->i_state & I_NEW)) {
 311                 inode->i_flags |= S_NOATIME;
 312                 if (!fc->writeback_cache || !S_ISREG(attr->mode))
 313                         inode->i_flags |= S_NOCMTIME;
 314                 inode->i_generation = generation;
 315                 fuse_init_inode(inode, attr);
 316                 unlock_new_inode(inode);
 317         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 318                 /* Inode has changed type, any I/O on the old should fail */
 319                 make_bad_inode(inode);
 320                 iput(inode);
 321                 goto retry;
 322         }
 323
 324         fi = get_fuse_inode(inode);
 325         spin_lock(&fc->lock);
 326         fi->nlookup++;
 327         spin_unlock(&fc->lock);
 328         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 329
 330         return inode;
 331 }
 332
 333 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 334                              loff_t offset, loff_t len)
 335 {
 336         struct inode *inode;
 337         pgoff_t pg_start;
 338         pgoff_t pg_end;
 339
 340         inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
 341         if (!inode)
 342                 return -ENOENT;
 343
 344         fuse_invalidate_attr(inode);
 345         forget_all_cached_acls(inode);
 346         if (offset >= 0) {
 347                 pg_start = offset >> PAGE_SHIFT;
 348                 if (len <= 0)
 349                         pg_end = -1;
 350                 else
 351                         pg_end = (offset + len - 1) >> PAGE_SHIFT;
 352                 invalidate_inode_pages2_range(inode->i_mapping,
 353                                               pg_start, pg_end);
 354         }
 355         iput(inode);
 356         return 0;
 357 }
 358
 359 void fuse_lock_inode(struct inode *inode)
 360 {
 361         if (!get_fuse_conn(inode)->parallel_dirops)
 362                 mutex_lock(&get_fuse_inode(inode)->mutex);
 363 }
 364
 365 void fuse_unlock_inode(struct inode *inode)
 366 {
 367         if (!get_fuse_conn(inode)->parallel_dirops)
 368                 mutex_unlock(&get_fuse_inode(inode)->mutex);
 369 }
 370
 371 static void fuse_umount_begin(struct super_block *sb)
 372 {
 373         fuse_abort_conn(get_fuse_conn_super(sb));
 374 }
 375
 376 static void fuse_send_destroy(struct fuse_conn *fc)
 377 {
 378         struct fuse_req *req = fc->destroy_req;
 379         if (req && fc->conn_init) {
 380                 fc->destroy_req = NULL;
 381                 req->in.h.opcode = FUSE_DESTROY;
 382                 __set_bit(FR_FORCE, &req->flags);
 383                 __clear_bit(FR_BACKGROUND, &req->flags);
 384                 fuse_request_send(fc, req);
 385                 fuse_put_request(fc, req);
 386         }
 387 }
 388
 389 static void fuse_put_super(struct super_block *sb)
 390 {
 391         struct fuse_conn *fc = get_fuse_conn_super(sb);
 392
 393         fuse_send_destroy(fc);
 394
 395         fuse_abort_conn(fc);
 396         mutex_lock(&fuse_mutex);
 397         list_del(&fc->entry);
 398         fuse_ctl_remove_conn(fc);
 399         mutex_unlock(&fuse_mutex);
 400
 401         fuse_conn_put(fc);
 402 }
 403
 404 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 405 {
 406         stbuf->f_type    = FUSE_SUPER_MAGIC;
 407         stbuf->f_bsize   = attr->bsize;
 408         stbuf->f_frsize  = attr->frsize;
 409         stbuf->f_blocks  = attr->blocks;
 410         stbuf->f_bfree   = attr->bfree;
 411         stbuf->f_bavail  = attr->bavail;
 412         stbuf->f_files   = attr->files;
 413         stbuf->f_ffree   = attr->ffree;
 414         stbuf->f_namelen = attr->namelen;
 415         /* fsid is left zero */
 416 }
 417
 418 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 419 {
 420         struct super_block *sb = dentry->d_sb;
 421         struct fuse_conn *fc = get_fuse_conn_super(sb);
 422         FUSE_ARGS(args);
 423         struct fuse_statfs_out outarg;
 424         int err;
 425
 426         if (!fuse_allow_current_process(fc)) {
 427                 buf->f_type = FUSE_SUPER_MAGIC;
 428                 return 0;
 429         }
 430
 431         memset(&outarg, 0, sizeof(outarg));
 432         args.in.numargs = 0;
 433         args.in.h.opcode = FUSE_STATFS;
 434         args.in.h.nodeid = get_node_id(d_inode(dentry));
 435         args.out.numargs = 1;
 436         args.out.args[0].size = sizeof(outarg);
 437         args.out.args[0].value = &outarg;
 438         err = fuse_simple_request(fc, &args);
 439         if (!err)
 440                 convert_fuse_statfs(buf, &outarg.st);
 441         return err;
 442 }
 443
 444 enum {
 445         OPT_FD,
 446         OPT_ROOTMODE,
 447         OPT_USER_ID,
 448         OPT_GROUP_ID,
 449         OPT_DEFAULT_PERMISSIONS,
 450         OPT_ALLOW_OTHER,
 451         OPT_MAX_READ,
 452         OPT_BLKSIZE,
 453         OPT_ERR
 454 };
 455
 456 static const match_table_t tokens = {
 457         {OPT_FD,                        "fd=%u"},
 458         {OPT_ROOTMODE,                  "rootmode=%o"},
 459         {OPT_USER_ID,                   "user_id=%u"},
 460         {OPT_GROUP_ID,                  "group_id=%u"},
 461         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 462         {OPT_ALLOW_OTHER,               "allow_other"},
 463         {OPT_MAX_READ,                  "max_read=%u"},
 464         {OPT_BLKSIZE,                   "blksize=%u"},
 465         {OPT_ERR,                       NULL}
 466 };
 467
 468 static int fuse_match_uint(substring_t *s, unsigned int *res)
 469 {
 470         int err = -ENOMEM;
 471         char *buf = match_strdup(s);
 472         if (buf) {
 473                 err = kstrtouint(buf, 10, res);
 474                 kfree(buf);
 475         }
 476         return err;
 477 }
 478
 479 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 480 {
 481         char *p;
 482         memset(d, 0, sizeof(struct fuse_mount_data));
 483         d->max_read = ~0;
 484         d->blksize = FUSE_DEFAULT_BLKSIZE;
 485
 486         while ((p = strsep(&opt, ",")) != NULL) {
 487                 int token;
 488                 int value;
 489                 unsigned uv;
 490                 substring_t args[MAX_OPT_ARGS];
 491                 if (!*p)
 492                         continue;
 493
 494                 token = match_token(p, tokens, args);
 495                 switch (token) {
 496                 case OPT_FD:
 497                         if (match_int(&args[0], &value))
 498                                 return 0;
 499                         d->fd = value;
 500                         d->fd_present = 1;
 501                         break;
 502
 503                 case OPT_ROOTMODE:
 504                         if (match_octal(&args[0], &value))
 505                                 return 0;
 506                         if (!fuse_valid_type(value))
 507                                 return 0;
 508                         d->rootmode = value;
 509                         d->rootmode_present = 1;
 510                         break;
 511
 512                 case OPT_USER_ID:
 513                         if (fuse_match_uint(&args[0], &uv))
 514                                 return 0;
 515                         d->user_id = make_kuid(current_user_ns(), uv);
 516                         if (!uid_valid(d->user_id))
 517                                 return 0;
 518                         d->user_id_present = 1;
 519                         break;
 520
 521                 case OPT_GROUP_ID:
 522                         if (fuse_match_uint(&args[0], &uv))
 523                                 return 0;
 524                         d->group_id = make_kgid(current_user_ns(), uv);
 525                         if (!gid_valid(d->group_id))
 526                                 return 0;
 527                         d->group_id_present = 1;
 528                         break;
 529
 530                 case OPT_DEFAULT_PERMISSIONS:
 531                         d->default_permissions = 1;
 532                         break;
 533
 534                 case OPT_ALLOW_OTHER:
 535                         d->allow_other = 1;
 536                         break;
 537
 538                 case OPT_MAX_READ:
 539                         if (match_int(&args[0], &value))
 540                                 return 0;
 541                         d->max_read = value;
 542                         break;
 543
 544                 case OPT_BLKSIZE:
 545                         if (!is_bdev || match_int(&args[0], &value))
 546                                 return 0;
 547                         d->blksize = value;
 548                         break;
 549
 550                 default:
 551                         return 0;
 552                 }
 553         }
 554
 555         if (!d->fd_present || !d->rootmode_present ||
 556             !d->user_id_present || !d->group_id_present)
 557                 return 0;
 558
 559         return 1;
 560 }
 561
 562 static int fuse_show_options(struct seq_file *m, struct dentry *root)
 563 {
 564         struct super_block *sb = root->d_sb;
 565         struct fuse_conn *fc = get_fuse_conn_super(sb);
 566
 567         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
 568         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
 569         if (fc->default_permissions)
 570                 seq_puts(m, ",default_permissions");
 571         if (fc->allow_other)
 572                 seq_puts(m, ",allow_other");
 573         if (fc->max_read != ~0)
 574                 seq_printf(m, ",max_read=%u", fc->max_read);
 575         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 576                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
 577         return 0;
 578 }
 579
 580 static void fuse_iqueue_init(struct fuse_iqueue *fiq)
 581 {
 582         memset(fiq, 0, sizeof(struct fuse_iqueue));
 583         init_waitqueue_head(&fiq->waitq);
 584         INIT_LIST_HEAD(&fiq->pending);
 585         INIT_LIST_HEAD(&fiq->interrupts);
 586         fiq->forget_list_tail = &fiq->forget_list_head;
 587         fiq->connected = 1;
 588 }
 589
 590 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
 591 {
 592         memset(fpq, 0, sizeof(struct fuse_pqueue));
 593         spin_lock_init(&fpq->lock);
 594         INIT_LIST_HEAD(&fpq->processing);
 595         INIT_LIST_HEAD(&fpq->io);
 596         fpq->connected = 1;
 597 }
 598
 599 void fuse_conn_init(struct fuse_conn *fc)
 600 {
 601         memset(fc, 0, sizeof(*fc));
 602         spin_lock_init(&fc->lock);
 603         init_rwsem(&fc->killsb);
 604         atomic_set(&fc->count, 1);
 605         atomic_set(&fc->dev_count, 1);
 606         init_waitqueue_head(&fc->blocked_waitq);
 607         init_waitqueue_head(&fc->reserved_req_waitq);
 608         fuse_iqueue_init(&fc->iq);
 609         INIT_LIST_HEAD(&fc->bg_queue);
 610         INIT_LIST_HEAD(&fc->entry);
 611         INIT_LIST_HEAD(&fc->devices);
 612         atomic_set(&fc->num_waiting, 0);
 613         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
 614         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 615         fc->khctr = 0;
 616         fc->polled_files = RB_ROOT;
 617         fc->blocked = 0;
 618         fc->initialized = 0;
 619         fc->connected = 1;
 620         fc->attr_version = 1;
 621         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 622 }
 623 EXPORT_SYMBOL_GPL(fuse_conn_init);
 624
 625 void fuse_conn_put(struct fuse_conn *fc)
 626 {
 627         if (atomic_dec_and_test(&fc->count)) {
 628                 if (fc->destroy_req)
 629                         fuse_request_free(fc->destroy_req);
 630                 fc->release(fc);
 631         }
 632 }
 633 EXPORT_SYMBOL_GPL(fuse_conn_put);
 634
 635 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 636 {
 637         atomic_inc(&fc->count);
 638         return fc;
 639 }
 640 EXPORT_SYMBOL_GPL(fuse_conn_get);
 641
 642 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 643 {
 644         struct fuse_attr attr;
 645         memset(&attr, 0, sizeof(attr));
 646
 647         attr.mode = mode;
 648         attr.ino = FUSE_ROOT_ID;
 649         attr.nlink = 1;
 650         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 651 }
 652
 653 struct fuse_inode_handle {
 654         u64 nodeid;
 655         u32 generation;
 656 };
 657
 658 static struct dentry *fuse_get_dentry(struct super_block *sb,
 659                                       struct fuse_inode_handle *handle)
 660 {
 661         struct fuse_conn *fc = get_fuse_conn_super(sb);
 662         struct inode *inode;
 663         struct dentry *entry;
 664         int err = -ESTALE;
 665
 666         if (handle->nodeid == 0)
 667                 goto out_err;
 668
 669         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
 670         if (!inode) {
 671                 struct fuse_entry_out outarg;
 672                 const struct qstr name = QSTR_INIT(".", 1);
 673
 674                 if (!fc->export_support)
 675                         goto out_err;
 676
 677                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
 678                                        &inode);
 679                 if (err && err != -ENOENT)
 680                         goto out_err;
 681                 if (err || !inode) {
 682                         err = -ESTALE;
 683                         goto out_err;
 684                 }
 685                 err = -EIO;
 686                 if (get_node_id(inode) != handle->nodeid)
 687                         goto out_iput;
 688         }
 689         err = -ESTALE;
 690         if (inode->i_generation != handle->generation)
 691                 goto out_iput;
 692
 693         entry = d_obtain_alias(inode);
 694         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
 695                 fuse_invalidate_entry_cache(entry);
 696
 697         return entry;
 698
 699  out_iput:
 700         iput(inode);
 701  out_err:
 702         return ERR_PTR(err);
 703 }
 704
 705 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 706                            struct inode *parent)
 707 {
 708         int len = parent ? 6 : 3;
 709         u64 nodeid;
 710         u32 generation;
 711
 712         if (*max_len < len) {
 713                 *max_len = len;
 714                 return  FILEID_INVALID;
 715         }
 716
 717         nodeid = get_fuse_inode(inode)->nodeid;
 718         generation = inode->i_generation;
 719
 720         fh[0] = (u32)(nodeid >> 32);
 721         fh[1] = (u32)(nodeid & 0xffffffff);
 722         fh[2] = generation;
 723
 724         if (parent) {
 725                 nodeid = get_fuse_inode(parent)->nodeid;
 726                 generation = parent->i_generation;
 727
 728                 fh[3] = (u32)(nodeid >> 32);
 729                 fh[4] = (u32)(nodeid & 0xffffffff);
 730                 fh[5] = generation;
 731         }
 732
 733         *max_len = len;
 734         return parent ? 0x82 : 0x81;
 735 }
 736
 737 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
 738                 struct fid *fid, int fh_len, int fh_type)
 739 {
 740         struct fuse_inode_handle handle;
 741
 742         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
 743                 return NULL;
 744
 745         handle.nodeid = (u64) fid->raw[0] << 32;
 746         handle.nodeid |= (u64) fid->raw[1];
 747         handle.generation = fid->raw[2];
 748         return fuse_get_dentry(sb, &handle);
 749 }
 750
 751 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
 752                 struct fid *fid, int fh_len, int fh_type)
 753 {
 754         struct fuse_inode_handle parent;
 755
 756         if (fh_type != 0x82 || fh_len < 6)
 757                 return NULL;
 758
 759         parent.nodeid = (u64) fid->raw[3] << 32;
 760         parent.nodeid |= (u64) fid->raw[4];
 761         parent.generation = fid->raw[5];
 762         return fuse_get_dentry(sb, &parent);
 763 }
 764
 765 static struct dentry *fuse_get_parent(struct dentry *child)
 766 {
 767         struct inode *child_inode = d_inode(child);
 768         struct fuse_conn *fc = get_fuse_conn(child_inode);
 769         struct inode *inode;
 770         struct dentry *parent;
 771         struct fuse_entry_out outarg;
 772         const struct qstr name = QSTR_INIT("..", 2);
 773         int err;
 774
 775         if (!fc->export_support)
 776                 return ERR_PTR(-ESTALE);
 777
 778         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 779                                &name, &outarg, &inode);
 780         if (err) {
 781                 if (err == -ENOENT)
 782                         return ERR_PTR(-ESTALE);
 783                 return ERR_PTR(err);
 784         }
 785
 786         parent = d_obtain_alias(inode);
 787         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
 788                 fuse_invalidate_entry_cache(parent);
 789
 790         return parent;
 791 }
 792
 793 static const struct export_operations fuse_export_operations = {
 794         .fh_to_dentry   = fuse_fh_to_dentry,
 795         .fh_to_parent   = fuse_fh_to_parent,
 796         .encode_fh      = fuse_encode_fh,
 797         .get_parent     = fuse_get_parent,
 798 };
 799
 800 static const struct super_operations fuse_super_operations = {
 801         .alloc_inode    = fuse_alloc_inode,
 802         .destroy_inode  = fuse_destroy_inode,
 803         .evict_inode    = fuse_evict_inode,
 804         .write_inode    = fuse_write_inode,
 805         .drop_inode     = generic_delete_inode,
 806         .remount_fs     = fuse_remount_fs,
 807         .put_super      = fuse_put_super,
 808         .umount_begin   = fuse_umount_begin,
 809         .statfs         = fuse_statfs,
 810         .show_options   = fuse_show_options,
 811 };
 812
 813 static void sanitize_global_limit(unsigned *limit)
 814 {
 815         if (*limit == 0)
 816                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
 817                          sizeof(struct fuse_req);
 818
 819         if (*limit >= 1 << 16)
 820                 *limit = (1 << 16) - 1;
 821 }
 822
 823 static int set_global_limit(const char *val, struct kernel_param *kp)
 824 {
 825         int rv;
 826
 827         rv = param_set_uint(val, kp);
 828         if (rv)
 829                 return rv;
 830
 831         sanitize_global_limit((unsigned *)kp->arg);
 832
 833         return 0;
 834 }
 835
 836 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
 837 {
 838         int cap_sys_admin = capable(CAP_SYS_ADMIN);
 839
 840         if (arg->minor < 13)
 841                 return;
 842
 843         sanitize_global_limit(&max_user_bgreq);
 844         sanitize_global_limit(&max_user_congthresh);
 845
 846         if (arg->max_background) {
 847                 fc->max_background = arg->max_background;
 848
 849                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
 850                         fc->max_background = max_user_bgreq;
 851         }
 852         if (arg->congestion_threshold) {
 853                 fc->congestion_threshold = arg->congestion_threshold;
 854
 855                 if (!cap_sys_admin &&
 856                     fc->congestion_threshold > max_user_congthresh)
 857                         fc->congestion_threshold = max_user_congthresh;
 858         }
 859 }
 860
 861 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 862 {
 863         struct fuse_init_out *arg = &req->misc.init_out;
 864
 865         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 866                 fc->conn_error = 1;
 867         else {
 868                 unsigned long ra_pages;
 869
 870                 process_init_limits(fc, arg);
 871
 872                 if (arg->minor >= 6) {
 873                         ra_pages = arg->max_readahead / PAGE_SIZE;
 874                         if (arg->flags & FUSE_ASYNC_READ)
 875                                 fc->async_read = 1;
 876                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 877                                 fc->no_lock = 1;
 878                         if (arg->minor >= 17) {
 879                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
 880                                         fc->no_flock = 1;
 881                         } else {
 882                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
 883                                         fc->no_flock = 1;
 884                         }
 885                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 886                                 fc->atomic_o_trunc = 1;
 887                         if (arg->minor >= 9) {
 888                                 /* LOOKUP has dependency on proto version */
 889                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
 890                                         fc->export_support = 1;
 891                         }
 892                         if (arg->flags & FUSE_BIG_WRITES)
 893                                 fc->big_writes = 1;
 894                         if (arg->flags & FUSE_DONT_MASK)
 895                                 fc->dont_mask = 1;
 896                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
 897                                 fc->auto_inval_data = 1;
 898                         if (arg->flags & FUSE_DO_READDIRPLUS) {
 899                                 fc->do_readdirplus = 1;
 900                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
 901                                         fc->readdirplus_auto = 1;
 902                         }
 903                         if (arg->flags & FUSE_ASYNC_DIO)
 904                                 fc->async_dio = 1;
 905                         if (arg->flags & FUSE_WRITEBACK_CACHE)
 906                                 fc->writeback_cache = 1;
 907                         if (arg->flags & FUSE_PARALLEL_DIROPS)
 908                                 fc->parallel_dirops = 1;
 909                         if (arg->flags & FUSE_HANDLE_KILLPRIV)
 910                                 fc->handle_killpriv = 1;
 911                         if (arg->time_gran && arg->time_gran <= 1000000000)
 912                                 fc->sb->s_time_gran = arg->time_gran;
 913                         if ((arg->flags & FUSE_POSIX_ACL)) {
 914                                 fc->default_permissions = 1;
 915                                 fc->posix_acl = 1;
 916                                 fc->sb->s_xattr = fuse_acl_xattr_handlers;
 917                         }
 918                 } else {
 919                         ra_pages = fc->max_read / PAGE_SIZE;
 920                         fc->no_lock = 1;
 921                         fc->no_flock = 1;
 922                 }
 923
 924                 fc->sb->s_bdi->ra_pages =
 925                                 min(fc->sb->s_bdi->ra_pages, ra_pages);
 926                 fc->minor = arg->minor;
 927                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 928                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
 929                 fc->conn_init = 1;
 930         }
 931         fuse_set_initialized(fc);
 932         wake_up_all(&fc->blocked_waitq);
 933 }
 934
 935 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 936 {
 937         struct fuse_init_in *arg = &req->misc.init_in;
 938
 939         arg->major = FUSE_KERNEL_VERSION;
 940         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 941         arg->max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE;
 942         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 943                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
 944                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
 945                 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 946                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 947                 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
 948                 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL;
 949         req->in.h.opcode = FUSE_INIT;
 950         req->in.numargs = 1;
 951         req->in.args[0].size = sizeof(*arg);
 952         req->in.args[0].value = arg;
 953         req->out.numargs = 1;
 954         /* Variable length argument used for backward compatibility
 955            with interface version < 7.5.  Rest of init_out is zeroed
 956            by do_get_request(), so a short reply is not a problem */
 957         req->out.argvar = 1;
 958         req->out.args[0].size = sizeof(struct fuse_init_out);
 959         req->out.args[0].value = &req->misc.init_out;
 960         req->end = process_init_reply;
 961         fuse_request_send_background(fc, req);
 962 }
 963
 964 static void fuse_free_conn(struct fuse_conn *fc)
 965 {
 966         WARN_ON(!list_empty(&fc->devices));
 967         kfree_rcu(fc, rcu);
 968 }
 969
 970 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 971 {
 972         int err;
 973         char *suffix = "";
 974
 975         if (sb->s_bdev)
 976                 suffix = "-fuseblk";
 977         err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
 978                                    MINOR(fc->dev), suffix);
 979         if (err)
 980                 return err;
 981
 982         sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
 983         /* fuse does it's own writeback accounting */
 984         sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 985
 986         /*
 987          * For a single fuse filesystem use max 1% of dirty +
 988          * writeback threshold.
 989          *
 990          * This gives about 1M of write buffer for memory maps on a
 991          * machine with 1G and 10% dirty_ratio, which should be more
 992          * than enough.
 993          *
 994          * Privileged users can raise it by writing to
 995          *
 996          *    /sys/class/bdi/<bdi>/max_ratio
 997          */
 998         bdi_set_max_ratio(sb->s_bdi, 1);
 999
1000         return 0;
1001 }
1002
1003 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
1004 {
1005         struct fuse_dev *fud;
1006
1007         fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1008         if (fud) {
1009                 fud->fc = fuse_conn_get(fc);
1010                 fuse_pqueue_init(&fud->pq);
1011
1012                 spin_lock(&fc->lock);
1013                 list_add_tail(&fud->entry, &fc->devices);
1014                 spin_unlock(&fc->lock);
1015         }
1016
1017         return fud;
1018 }
1019 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1020
1021 void fuse_dev_free(struct fuse_dev *fud)
1022 {
1023         struct fuse_conn *fc = fud->fc;
1024
1025         if (fc) {
1026                 spin_lock(&fc->lock);
1027                 list_del(&fud->entry);
1028                 spin_unlock(&fc->lock);
1029
1030                 fuse_conn_put(fc);
1031         }
1032         kfree(fud);
1033 }
1034 EXPORT_SYMBOL_GPL(fuse_dev_free);
1035
1036 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1037 {
1038         struct fuse_dev *fud;
1039         struct fuse_conn *fc;
1040         struct inode *root;
1041         struct fuse_mount_data d;
1042         struct file *file;
1043         struct dentry *root_dentry;
1044         struct fuse_req *init_req;
1045         int err;
1046         int is_bdev = sb->s_bdev != NULL;
1047
1048         err = -EINVAL;
1049         if (sb->s_flags & MS_MANDLOCK)
1050                 goto err;
1051
1052         sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1053
1054         if (!parse_fuse_opt(data, &d, is_bdev))
1055                 goto err;
1056
1057         if (is_bdev) {
1058 #ifdef CONFIG_BLOCK
1059                 err = -EINVAL;
1060                 if (!sb_set_blocksize(sb, d.blksize))
1061                         goto err;
1062 #endif
1063         } else {
1064                 sb->s_blocksize = PAGE_SIZE;
1065                 sb->s_blocksize_bits = PAGE_SHIFT;
1066         }
1067         sb->s_magic = FUSE_SUPER_MAGIC;
1068         sb->s_op = &fuse_super_operations;
1069         sb->s_xattr = fuse_xattr_handlers;
1070         sb->s_maxbytes = MAX_LFS_FILESIZE;
1071         sb->s_time_gran = 1;
1072         sb->s_export_op = &fuse_export_operations;
1073
1074         file = fget(d.fd);
1075         err = -EINVAL;
1076         if (!file)
1077                 goto err;
1078
1079         if ((file->f_op != &fuse_dev_operations) ||
1080             (file->f_cred->user_ns != &init_user_ns))
1081                 goto err_fput;
1082
1083         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1084         err = -ENOMEM;
1085         if (!fc)
1086                 goto err_fput;
1087
1088         fuse_conn_init(fc);
1089         fc->release = fuse_free_conn;
1090
1091         fud = fuse_dev_alloc(fc);
1092         if (!fud)
1093                 goto err_put_conn;
1094
1095         fc->dev = sb->s_dev;
1096         fc->sb = sb;
1097         err = fuse_bdi_init(fc, sb);
1098         if (err)
1099                 goto err_dev_free;
1100
1101         /* Handle umasking inside the fuse code */
1102         if (sb->s_flags & MS_POSIXACL)
1103                 fc->dont_mask = 1;
1104         sb->s_flags |= MS_POSIXACL;
1105
1106         fc->default_permissions = d.default_permissions;
1107         fc->allow_other = d.allow_other;
1108         fc->user_id = d.user_id;
1109         fc->group_id = d.group_id;
1110         fc->max_read = max_t(unsigned, 4096, d.max_read);
1111
1112         /* Used by get_root_inode() */
1113         sb->s_fs_info = fc;
1114
1115         err = -ENOMEM;
1116         root = fuse_get_root_inode(sb, d.rootmode);
1117         sb->s_d_op = &fuse_root_dentry_operations;
1118         root_dentry = d_make_root(root);
1119         if (!root_dentry)
1120                 goto err_dev_free;
1121         /* Root dentry doesn't have .d_revalidate */
1122         sb->s_d_op = &fuse_dentry_operations;
1123
1124         init_req = fuse_request_alloc(0);
1125         if (!init_req)
1126                 goto err_put_root;
1127         __set_bit(FR_BACKGROUND, &init_req->flags);
1128
1129         if (is_bdev) {
1130                 fc->destroy_req = fuse_request_alloc(0);
1131                 if (!fc->destroy_req)
1132                         goto err_free_init_req;
1133         }
1134
1135         mutex_lock(&fuse_mutex);
1136         err = -EINVAL;
1137         if (file->private_data)
1138                 goto err_unlock;
1139
1140         err = fuse_ctl_add_conn(fc);
1141         if (err)
1142                 goto err_unlock;
1143
1144         list_add_tail(&fc->entry, &fuse_conn_list);
1145         sb->s_root = root_dentry;
1146         file->private_data = fud;
1147         mutex_unlock(&fuse_mutex);
1148         /*
1149          * atomic_dec_and_test() in fput() provides the necessary
1150          * memory barrier for file->private_data to be visible on all
1151          * CPUs after this
1152          */
1153         fput(file);
1154
1155         fuse_send_init(fc, init_req);
1156
1157         return 0;
1158
1159  err_unlock:
1160         mutex_unlock(&fuse_mutex);
1161  err_free_init_req:
1162         fuse_request_free(init_req);
1163  err_put_root:
1164         dput(root_dentry);
1165  err_dev_free:
1166         fuse_dev_free(fud);
1167  err_put_conn:
1168         fuse_conn_put(fc);
1169  err_fput:
1170         fput(file);
1171  err:
1172         return err;
1173 }
1174
1175 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1176                        int flags, const char *dev_name,
1177                        void *raw_data)
1178 {
1179         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1180 }
1181
1182 static void fuse_kill_sb_anon(struct super_block *sb)
1183 {
1184         struct fuse_conn *fc = get_fuse_conn_super(sb);
1185
1186         if (fc) {
1187                 down_write(&fc->killsb);
1188                 fc->sb = NULL;
1189                 up_write(&fc->killsb);
1190         }
1191
1192         kill_anon_super(sb);
1193 }
1194
1195 static struct file_system_type fuse_fs_type = {
1196         .owner          = THIS_MODULE,
1197         .name           = "fuse",
1198         .fs_flags       = FS_HAS_SUBTYPE,
1199         .mount          = fuse_mount,
1200         .kill_sb        = fuse_kill_sb_anon,
1201 };
1202 MODULE_ALIAS_FS("fuse");
1203
1204 #ifdef CONFIG_BLOCK
1205 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1206                            int flags, const char *dev_name,
1207                            void *raw_data)
1208 {
1209         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1210 }
1211
1212 static void fuse_kill_sb_blk(struct super_block *sb)
1213 {
1214         struct fuse_conn *fc = get_fuse_conn_super(sb);
1215
1216         if (fc) {
1217                 down_write(&fc->killsb);
1218                 fc->sb = NULL;
1219                 up_write(&fc->killsb);
1220         }
1221
1222         kill_block_super(sb);
1223 }
1224
1225 static struct file_system_type fuseblk_fs_type = {
1226         .owner          = THIS_MODULE,
1227         .name           = "fuseblk",
1228         .mount          = fuse_mount_blk,
1229         .kill_sb        = fuse_kill_sb_blk,
1230         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1231 };
1232 MODULE_ALIAS_FS("fuseblk");
1233
1234 static inline int register_fuseblk(void)
1235 {
1236         return register_filesystem(&fuseblk_fs_type);
1237 }
1238
1239 static inline void unregister_fuseblk(void)
1240 {
1241         unregister_filesystem(&fuseblk_fs_type);
1242 }
1243 #else
1244 static inline int register_fuseblk(void)
1245 {
1246         return 0;
1247 }
1248
1249 static inline void unregister_fuseblk(void)
1250 {
1251 }
1252 #endif
1253
1254 static void fuse_inode_init_once(void *foo)
1255 {
1256         struct inode *inode = foo;
1257
1258         inode_init_once(inode);
1259 }
1260
1261 static int __init fuse_fs_init(void)
1262 {
1263         int err;
1264
1265         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1266                                               sizeof(struct fuse_inode), 0,
1267                                               SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
1268                                               fuse_inode_init_once);
1269         err = -ENOMEM;
1270         if (!fuse_inode_cachep)
1271                 goto out;
1272
1273         err = register_fuseblk();
1274         if (err)
1275                 goto out2;
1276
1277         err = register_filesystem(&fuse_fs_type);
1278         if (err)
1279                 goto out3;
1280
1281         return 0;
1282
1283  out3:
1284         unregister_fuseblk();
1285  out2:
1286         kmem_cache_destroy(fuse_inode_cachep);
1287  out:
1288         return err;
1289 }
1290
1291 static void fuse_fs_cleanup(void)
1292 {
1293         unregister_filesystem(&fuse_fs_type);
1294         unregister_fuseblk();
1295
1296         /*
1297          * Make sure all delayed rcu free inodes are flushed before we
1298          * destroy cache.
1299          */
1300         rcu_barrier();
1301         kmem_cache_destroy(fuse_inode_cachep);
1302 }
1303
1304 static struct kobject *fuse_kobj;
1305
1306 static int fuse_sysfs_init(void)
1307 {
1308         int err;
1309
1310         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1311         if (!fuse_kobj) {
1312                 err = -ENOMEM;
1313                 goto out_err;
1314         }
1315
1316         err = sysfs_create_mount_point(fuse_kobj, "connections");
1317         if (err)
1318                 goto out_fuse_unregister;
1319
1320         return 0;
1321
1322  out_fuse_unregister:
1323         kobject_put(fuse_kobj);
1324  out_err:
1325         return err;
1326 }
1327
1328 static void fuse_sysfs_cleanup(void)
1329 {
1330         sysfs_remove_mount_point(fuse_kobj, "connections");
1331         kobject_put(fuse_kobj);
1332 }
1333
1334 static int __init fuse_init(void)
1335 {
1336         int res;
1337
1338         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1339                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1340
1341         INIT_LIST_HEAD(&fuse_conn_list);
1342         res = fuse_fs_init();
1343         if (res)
1344                 goto err;
1345
1346         res = fuse_dev_init();
1347         if (res)
1348                 goto err_fs_cleanup;
1349
1350         res = fuse_sysfs_init();
1351         if (res)
1352                 goto err_dev_cleanup;
1353
1354         res = fuse_ctl_init();
1355         if (res)
1356                 goto err_sysfs_cleanup;
1357
1358         sanitize_global_limit(&max_user_bgreq);
1359         sanitize_global_limit(&max_user_congthresh);
1360
1361         return 0;
1362
1363  err_sysfs_cleanup:
1364         fuse_sysfs_cleanup();
1365  err_dev_cleanup:
1366         fuse_dev_cleanup();
1367  err_fs_cleanup:
1368         fuse_fs_cleanup();
1369  err:
1370         return res;
1371 }
1372
1373 static void __exit fuse_exit(void)
1374 {
1375         printk(KERN_DEBUG "fuse exit\n");
1376
1377         fuse_ctl_cleanup();
1378         fuse_sysfs_cleanup();
1379         fuse_fs_cleanup();
1380         fuse_dev_cleanup();
1381 }
1382
1383 module_init(fuse_init);
1384 module_exit(fuse_exit);