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