linux/fs/fuse/inode.c
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   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#include <linux/pid_namespace.h>
  25
  26MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  27MODULE_DESCRIPTION("Filesystem in Userspace");
  28MODULE_LICENSE("GPL");
  29
  30static struct kmem_cache *fuse_inode_cachep;
  31struct list_head fuse_conn_list;
  32DEFINE_MUTEX(fuse_mutex);
  33
  34static int set_global_limit(const char *val, struct kernel_param *kp);
  35
  36unsigned max_user_bgreq;
  37module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
  38                  &max_user_bgreq, 0644);
  39__MODULE_PARM_TYPE(max_user_bgreq, "uint");
  40MODULE_PARM_DESC(max_user_bgreq,
  41 "Global limit for the maximum number of backgrounded requests an "
  42 "unprivileged user can set");
  43
  44unsigned max_user_congthresh;
  45module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
  46                  &max_user_congthresh, 0644);
  47__MODULE_PARM_TYPE(max_user_congthresh, "uint");
  48MODULE_PARM_DESC(max_user_congthresh,
  49 "Global limit for the maximum congestion threshold an "
  50 "unprivileged user can set");
  51
  52#define FUSE_SUPER_MAGIC 0x65735546
  53
  54#define FUSE_DEFAULT_BLKSIZE 512
  55
  56/** Maximum number of outstanding background requests */
  57#define FUSE_DEFAULT_MAX_BACKGROUND 12
  58
  59/** Congestion starts at 75% of maximum */
  60#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
  61
  62struct fuse_mount_data {
  63        int fd;
  64        unsigned rootmode;
  65        kuid_t user_id;
  66        kgid_t group_id;
  67        unsigned fd_present:1;
  68        unsigned rootmode_present:1;
  69        unsigned user_id_present:1;
  70        unsigned group_id_present:1;
  71        unsigned default_permissions:1;
  72        unsigned allow_other:1;
  73        unsigned max_read;
  74        unsigned blksize;
  75};
  76
  77struct fuse_forget_link *fuse_alloc_forget(void)
  78{
  79        return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
  80}
  81
  82static struct inode *fuse_alloc_inode(struct super_block *sb)
  83{
  84        struct inode *inode;
  85        struct fuse_inode *fi;
  86
  87        inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  88        if (!inode)
  89                return NULL;
  90
  91        fi = get_fuse_inode(inode);
  92        fi->i_time = 0;
  93        fi->nodeid = 0;
  94        fi->nlookup = 0;
  95        fi->attr_version = 0;
  96        fi->writectr = 0;
  97        fi->orig_ino = 0;
  98        fi->state = 0;
  99        INIT_LIST_HEAD(&fi->write_files);
 100        INIT_LIST_HEAD(&fi->queued_writes);
 101        INIT_LIST_HEAD(&fi->writepages);
 102        init_waitqueue_head(&fi->page_waitq);
 103        mutex_init(&fi->mutex);
 104        fi->forget = fuse_alloc_forget();
 105        if (!fi->forget) {
 106                kmem_cache_free(fuse_inode_cachep, inode);
 107                return NULL;
 108        }
 109
 110        return inode;
 111}
 112
 113static void fuse_i_callback(struct rcu_head *head)
 114{
 115        struct inode *inode = container_of(head, struct inode, i_rcu);
 116        kmem_cache_free(fuse_inode_cachep, inode);
 117}
 118
 119static void fuse_destroy_inode(struct inode *inode)
 120{
 121        struct fuse_inode *fi = get_fuse_inode(inode);
 122        BUG_ON(!list_empty(&fi->write_files));
 123        BUG_ON(!list_empty(&fi->queued_writes));
 124        mutex_destroy(&fi->mutex);
 125        kfree(fi->forget);
 126        call_rcu(&inode->i_rcu, fuse_i_callback);
 127}
 128
 129static void fuse_evict_inode(struct inode *inode)
 130{
 131        truncate_inode_pages_final(&inode->i_data);
 132        clear_inode(inode);
 133        if (inode->i_sb->s_flags & MS_ACTIVE) {
 134                struct fuse_conn *fc = get_fuse_conn(inode);
 135                struct fuse_inode *fi = get_fuse_inode(inode);
 136                fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
 137                fi->forget = NULL;
 138        }
 139}
 140
 141static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 142{
 143        sync_filesystem(sb);
 144        if (*flags & MS_MANDLOCK)
 145                return -EINVAL;
 146
 147        return 0;
 148}
 149
 150/*
 151 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
 152 * so that it will fit.
 153 */
 154static ino_t fuse_squash_ino(u64 ino64)
 155{
 156        ino_t ino = (ino_t) ino64;
 157        if (sizeof(ino_t) < sizeof(u64))
 158                ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
 159        return ino;
 160}
 161
 162void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 163                                   u64 attr_valid)
 164{
 165        struct fuse_conn *fc = get_fuse_conn(inode);
 166        struct fuse_inode *fi = get_fuse_inode(inode);
 167
 168        fi->attr_version = ++fc->attr_version;
 169        fi->i_time = attr_valid;
 170
 171        inode->i_ino     = fuse_squash_ino(attr->ino);
 172        inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 173        set_nlink(inode, attr->nlink);
 174        inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
 175        inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
 176        inode->i_blocks  = attr->blocks;
 177        inode->i_atime.tv_sec   = attr->atime;
 178        inode->i_atime.tv_nsec  = attr->atimensec;
 179        /* mtime from server may be stale due to local buffered write */
 180        if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
 181                inode->i_mtime.tv_sec   = attr->mtime;
 182                inode->i_mtime.tv_nsec  = attr->mtimensec;
 183                inode->i_ctime.tv_sec   = attr->ctime;
 184                inode->i_ctime.tv_nsec  = attr->ctimensec;
 185        }
 186
 187        if (attr->blksize != 0)
 188                inode->i_blkbits = ilog2(attr->blksize);
 189        else
 190                inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 191
 192        /*
 193         * Don't set the sticky bit in i_mode, unless we want the VFS
 194         * to check permissions.  This prevents failures due to the
 195         * check in may_delete().
 196         */
 197        fi->orig_i_mode = inode->i_mode;
 198        if (!fc->default_permissions)
 199                inode->i_mode &= ~S_ISVTX;
 200
 201        fi->orig_ino = attr->ino;
 202}
 203
 204void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 205                            u64 attr_valid, u64 attr_version)
 206{
 207        struct fuse_conn *fc = get_fuse_conn(inode);
 208        struct fuse_inode *fi = get_fuse_inode(inode);
 209        bool is_wb = fc->writeback_cache;
 210        loff_t oldsize;
 211        struct timespec old_mtime;
 212
 213        spin_lock(&fc->lock);
 214        if ((attr_version != 0 && fi->attr_version > attr_version) ||
 215            test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
 216                spin_unlock(&fc->lock);
 217                return;
 218        }
 219
 220        old_mtime = inode->i_mtime;
 221        fuse_change_attributes_common(inode, attr, attr_valid);
 222
 223        oldsize = inode->i_size;
 224        /*
 225         * In case of writeback_cache enabled, the cached writes beyond EOF
 226         * extend local i_size without keeping userspace server in sync. So,
 227         * attr->size coming from server can be stale. We cannot trust it.
 228         */
 229        if (!is_wb || !S_ISREG(inode->i_mode))
 230                i_size_write(inode, attr->size);
 231        spin_unlock(&fc->lock);
 232
 233        if (!is_wb && S_ISREG(inode->i_mode)) {
 234                bool inval = false;
 235
 236                if (oldsize != attr->size) {
 237                        truncate_pagecache(inode, attr->size);
 238                        inval = true;
 239                } else if (fc->auto_inval_data) {
 240                        struct timespec new_mtime = {
 241                                .tv_sec = attr->mtime,
 242                                .tv_nsec = attr->mtimensec,
 243                        };
 244
 245                        /*
 246                         * Auto inval mode also checks and invalidates if mtime
 247                         * has changed.
 248                         */
 249                        if (!timespec_equal(&old_mtime, &new_mtime))
 250                                inval = true;
 251                }
 252
 253                if (inval)
 254                        invalidate_inode_pages2(inode->i_mapping);
 255        }
 256}
 257
 258static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 259{
 260        inode->i_mode = attr->mode & S_IFMT;
 261        inode->i_size = attr->size;
 262        inode->i_mtime.tv_sec  = attr->mtime;
 263        inode->i_mtime.tv_nsec = attr->mtimensec;
 264        inode->i_ctime.tv_sec  = attr->ctime;
 265        inode->i_ctime.tv_nsec = attr->ctimensec;
 266        if (S_ISREG(inode->i_mode)) {
 267                fuse_init_common(inode);
 268                fuse_init_file_inode(inode);
 269        } else if (S_ISDIR(inode->i_mode))
 270                fuse_init_dir(inode);
 271        else if (S_ISLNK(inode->i_mode))
 272                fuse_init_symlink(inode);
 273        else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 274                 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 275                fuse_init_common(inode);
 276                init_special_inode(inode, inode->i_mode,
 277                                   new_decode_dev(attr->rdev));
 278        } else
 279                BUG();
 280}
 281
 282int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 283{
 284        u64 nodeid = *(u64 *) _nodeidp;
 285        if (get_node_id(inode) == nodeid)
 286                return 1;
 287        else
 288                return 0;
 289}
 290
 291static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 292{
 293        u64 nodeid = *(u64 *) _nodeidp;
 294        get_fuse_inode(inode)->nodeid = nodeid;
 295        return 0;
 296}
 297
 298struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 299                        int generation, struct fuse_attr *attr,
 300                        u64 attr_valid, u64 attr_version)
 301{
 302        struct inode *inode;
 303        struct fuse_inode *fi;
 304        struct fuse_conn *fc = get_fuse_conn_super(sb);
 305
 306 retry:
 307        inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 308        if (!inode)
 309                return NULL;
 310
 311        if ((inode->i_state & I_NEW)) {
 312                inode->i_flags |= S_NOATIME;
 313                if (!fc->writeback_cache || !S_ISREG(attr->mode))
 314                        inode->i_flags |= S_NOCMTIME;
 315                inode->i_generation = generation;
 316                fuse_init_inode(inode, attr);
 317                unlock_new_inode(inode);
 318        } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 319                /* Inode has changed type, any I/O on the old should fail */
 320                make_bad_inode(inode);
 321                iput(inode);
 322                goto retry;
 323        }
 324
 325        fi = get_fuse_inode(inode);
 326        spin_lock(&fc->lock);
 327        fi->nlookup++;
 328        spin_unlock(&fc->lock);
 329        fuse_change_attributes(inode, attr, attr_valid, attr_version);
 330
 331        return inode;
 332}
 333
 334int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 335                             loff_t offset, loff_t len)
 336{
 337        struct inode *inode;
 338        pgoff_t pg_start;
 339        pgoff_t pg_end;
 340
 341        inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
 342        if (!inode)
 343                return -ENOENT;
 344
 345        fuse_invalidate_attr(inode);
 346        forget_all_cached_acls(inode);
 347        if (offset >= 0) {
 348                pg_start = offset >> PAGE_SHIFT;
 349                if (len <= 0)
 350                        pg_end = -1;
 351                else
 352                        pg_end = (offset + len - 1) >> PAGE_SHIFT;
 353                invalidate_inode_pages2_range(inode->i_mapping,
 354                                              pg_start, pg_end);
 355        }
 356        iput(inode);
 357        return 0;
 358}
 359
 360void fuse_lock_inode(struct inode *inode)
 361{
 362        if (!get_fuse_conn(inode)->parallel_dirops)
 363                mutex_lock(&get_fuse_inode(inode)->mutex);
 364}
 365
 366void fuse_unlock_inode(struct inode *inode)
 367{
 368        if (!get_fuse_conn(inode)->parallel_dirops)
 369                mutex_unlock(&get_fuse_inode(inode)->mutex);
 370}
 371
 372static void fuse_umount_begin(struct super_block *sb)
 373{
 374        fuse_abort_conn(get_fuse_conn_super(sb));
 375}
 376
 377static void fuse_send_destroy(struct fuse_conn *fc)
 378{
 379        struct fuse_req *req = fc->destroy_req;
 380        if (req && fc->conn_init) {
 381                fc->destroy_req = NULL;
 382                req->in.h.opcode = FUSE_DESTROY;
 383                __set_bit(FR_FORCE, &req->flags);
 384                __clear_bit(FR_BACKGROUND, &req->flags);
 385                fuse_request_send(fc, req);
 386                fuse_put_request(fc, req);
 387        }
 388}
 389
 390static void fuse_put_super(struct super_block *sb)
 391{
 392        struct fuse_conn *fc = get_fuse_conn_super(sb);
 393
 394        fuse_send_destroy(fc);
 395
 396        fuse_abort_conn(fc);
 397        mutex_lock(&fuse_mutex);
 398        list_del(&fc->entry);
 399        fuse_ctl_remove_conn(fc);
 400        mutex_unlock(&fuse_mutex);
 401
 402        fuse_conn_put(fc);
 403}
 404
 405static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 406{
 407        stbuf->f_type    = FUSE_SUPER_MAGIC;
 408        stbuf->f_bsize   = attr->bsize;
 409        stbuf->f_frsize  = attr->frsize;
 410        stbuf->f_blocks  = attr->blocks;
 411        stbuf->f_bfree   = attr->bfree;
 412        stbuf->f_bavail  = attr->bavail;
 413        stbuf->f_files   = attr->files;
 414        stbuf->f_ffree   = attr->ffree;
 415        stbuf->f_namelen = attr->namelen;
 416        /* fsid is left zero */
 417}
 418
 419static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 420{
 421        struct super_block *sb = dentry->d_sb;
 422        struct fuse_conn *fc = get_fuse_conn_super(sb);
 423        FUSE_ARGS(args);
 424        struct fuse_statfs_out outarg;
 425        int err;
 426
 427        if (!fuse_allow_current_process(fc)) {
 428                buf->f_type = FUSE_SUPER_MAGIC;
 429                return 0;
 430        }
 431
 432        memset(&outarg, 0, sizeof(outarg));
 433        args.in.numargs = 0;
 434        args.in.h.opcode = FUSE_STATFS;
 435        args.in.h.nodeid = get_node_id(d_inode(dentry));
 436        args.out.numargs = 1;
 437        args.out.args[0].size = sizeof(outarg);
 438        args.out.args[0].value = &outarg;
 439        err = fuse_simple_request(fc, &args);
 440        if (!err)
 441                convert_fuse_statfs(buf, &outarg.st);
 442        return err;
 443}
 444
 445enum {
 446        OPT_FD,
 447        OPT_ROOTMODE,
 448        OPT_USER_ID,
 449        OPT_GROUP_ID,
 450        OPT_DEFAULT_PERMISSIONS,
 451        OPT_ALLOW_OTHER,
 452        OPT_MAX_READ,
 453        OPT_BLKSIZE,
 454        OPT_ERR
 455};
 456
 457static const match_table_t tokens = {
 458        {OPT_FD,                        "fd=%u"},
 459        {OPT_ROOTMODE,                  "rootmode=%o"},
 460        {OPT_USER_ID,                   "user_id=%u"},
 461        {OPT_GROUP_ID,                  "group_id=%u"},
 462        {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 463        {OPT_ALLOW_OTHER,               "allow_other"},
 464        {OPT_MAX_READ,                  "max_read=%u"},
 465        {OPT_BLKSIZE,                   "blksize=%u"},
 466        {OPT_ERR,                       NULL}
 467};
 468
 469static int fuse_match_uint(substring_t *s, unsigned int *res)
 470{
 471        int err = -ENOMEM;
 472        char *buf = match_strdup(s);
 473        if (buf) {
 474                err = kstrtouint(buf, 10, res);
 475                kfree(buf);
 476        }
 477        return err;
 478}
 479
 480static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 481{
 482        char *p;
 483        memset(d, 0, sizeof(struct fuse_mount_data));
 484        d->max_read = ~0;
 485        d->blksize = FUSE_DEFAULT_BLKSIZE;
 486
 487        while ((p = strsep(&opt, ",")) != NULL) {
 488                int token;
 489                int value;
 490                unsigned uv;
 491                substring_t args[MAX_OPT_ARGS];
 492                if (!*p)
 493                        continue;
 494
 495                token = match_token(p, tokens, args);
 496                switch (token) {
 497                case OPT_FD:
 498                        if (match_int(&args[0], &value))
 499                                return 0;
 500                        d->fd = value;
 501                        d->fd_present = 1;
 502                        break;
 503
 504                case OPT_ROOTMODE:
 505                        if (match_octal(&args[0], &value))
 506                                return 0;
 507                        if (!fuse_valid_type(value))
 508                                return 0;
 509                        d->rootmode = value;
 510                        d->rootmode_present = 1;
 511                        break;
 512
 513                case OPT_USER_ID:
 514                        if (fuse_match_uint(&args[0], &uv))
 515                                return 0;
 516                        d->user_id = make_kuid(current_user_ns(), uv);
 517                        if (!uid_valid(d->user_id))
 518                                return 0;
 519                        d->user_id_present = 1;
 520                        break;
 521
 522                case OPT_GROUP_ID:
 523                        if (fuse_match_uint(&args[0], &uv))
 524                                return 0;
 525                        d->group_id = make_kgid(current_user_ns(), uv);
 526                        if (!gid_valid(d->group_id))
 527                                return 0;
 528                        d->group_id_present = 1;
 529                        break;
 530
 531                case OPT_DEFAULT_PERMISSIONS:
 532                        d->default_permissions = 1;
 533                        break;
 534
 535                case OPT_ALLOW_OTHER:
 536                        d->allow_other = 1;
 537                        break;
 538
 539                case OPT_MAX_READ:
 540                        if (match_int(&args[0], &value))
 541                                return 0;
 542                        d->max_read = value;
 543                        break;
 544
 545                case OPT_BLKSIZE:
 546                        if (!is_bdev || match_int(&args[0], &value))
 547                                return 0;
 548                        d->blksize = value;
 549                        break;
 550
 551                default:
 552                        return 0;
 553                }
 554        }
 555
 556        if (!d->fd_present || !d->rootmode_present ||
 557            !d->user_id_present || !d->group_id_present)
 558                return 0;
 559
 560        return 1;
 561}
 562
 563static int fuse_show_options(struct seq_file *m, struct dentry *root)
 564{
 565        struct super_block *sb = root->d_sb;
 566        struct fuse_conn *fc = get_fuse_conn_super(sb);
 567
 568        seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
 569        seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
 570        if (fc->default_permissions)
 571                seq_puts(m, ",default_permissions");
 572        if (fc->allow_other)
 573                seq_puts(m, ",allow_other");
 574        if (fc->max_read != ~0)
 575                seq_printf(m, ",max_read=%u", fc->max_read);
 576        if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 577                seq_printf(m, ",blksize=%lu", sb->s_blocksize);
 578        return 0;
 579}
 580
 581static void fuse_iqueue_init(struct fuse_iqueue *fiq)
 582{
 583        memset(fiq, 0, sizeof(struct fuse_iqueue));
 584        init_waitqueue_head(&fiq->waitq);
 585        INIT_LIST_HEAD(&fiq->pending);
 586        INIT_LIST_HEAD(&fiq->interrupts);
 587        fiq->forget_list_tail = &fiq->forget_list_head;
 588        fiq->connected = 1;
 589}
 590
 591static void fuse_pqueue_init(struct fuse_pqueue *fpq)
 592{
 593        memset(fpq, 0, sizeof(struct fuse_pqueue));
 594        spin_lock_init(&fpq->lock);
 595        INIT_LIST_HEAD(&fpq->processing);
 596        INIT_LIST_HEAD(&fpq->io);
 597        fpq->connected = 1;
 598}
 599
 600void fuse_conn_init(struct fuse_conn *fc)
 601{
 602        memset(fc, 0, sizeof(*fc));
 603        spin_lock_init(&fc->lock);
 604        init_rwsem(&fc->killsb);
 605        refcount_set(&fc->count, 1);
 606        atomic_set(&fc->dev_count, 1);
 607        init_waitqueue_head(&fc->blocked_waitq);
 608        init_waitqueue_head(&fc->reserved_req_waitq);
 609        fuse_iqueue_init(&fc->iq);
 610        INIT_LIST_HEAD(&fc->bg_queue);
 611        INIT_LIST_HEAD(&fc->entry);
 612        INIT_LIST_HEAD(&fc->devices);
 613        atomic_set(&fc->num_waiting, 0);
 614        fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
 615        fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 616        fc->khctr = 0;
 617        fc->polled_files = RB_ROOT;
 618        fc->blocked = 0;
 619        fc->initialized = 0;
 620        fc->connected = 1;
 621        fc->attr_version = 1;
 622        get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 623        fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
 624}
 625EXPORT_SYMBOL_GPL(fuse_conn_init);
 626
 627void fuse_conn_put(struct fuse_conn *fc)
 628{
 629        if (refcount_dec_and_test(&fc->count)) {
 630                if (fc->destroy_req)
 631                        fuse_request_free(fc->destroy_req);
 632                put_pid_ns(fc->pid_ns);
 633                fc->release(fc);
 634        }
 635}
 636EXPORT_SYMBOL_GPL(fuse_conn_put);
 637
 638struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 639{
 640        refcount_inc(&fc->count);
 641        return fc;
 642}
 643EXPORT_SYMBOL_GPL(fuse_conn_get);
 644
 645static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 646{
 647        struct fuse_attr attr;
 648        memset(&attr, 0, sizeof(attr));
 649
 650        attr.mode = mode;
 651        attr.ino = FUSE_ROOT_ID;
 652        attr.nlink = 1;
 653        return fuse_iget(sb, 1, 0, &attr, 0, 0);
 654}
 655
 656struct fuse_inode_handle {
 657        u64 nodeid;
 658        u32 generation;
 659};
 660
 661static struct dentry *fuse_get_dentry(struct super_block *sb,
 662                                      struct fuse_inode_handle *handle)
 663{
 664        struct fuse_conn *fc = get_fuse_conn_super(sb);
 665        struct inode *inode;
 666        struct dentry *entry;
 667        int err = -ESTALE;
 668
 669        if (handle->nodeid == 0)
 670                goto out_err;
 671
 672        inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
 673        if (!inode) {
 674                struct fuse_entry_out outarg;
 675                const struct qstr name = QSTR_INIT(".", 1);
 676
 677                if (!fc->export_support)
 678                        goto out_err;
 679
 680                err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
 681                                       &inode);
 682                if (err && err != -ENOENT)
 683                        goto out_err;
 684                if (err || !inode) {
 685                        err = -ESTALE;
 686                        goto out_err;
 687                }
 688                err = -EIO;
 689                if (get_node_id(inode) != handle->nodeid)
 690                        goto out_iput;
 691        }
 692        err = -ESTALE;
 693        if (inode->i_generation != handle->generation)
 694                goto out_iput;
 695
 696        entry = d_obtain_alias(inode);
 697        if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
 698                fuse_invalidate_entry_cache(entry);
 699
 700        return entry;
 701
 702 out_iput:
 703        iput(inode);
 704 out_err:
 705        return ERR_PTR(err);
 706}
 707
 708static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 709                           struct inode *parent)
 710{
 711        int len = parent ? 6 : 3;
 712        u64 nodeid;
 713        u32 generation;
 714
 715        if (*max_len < len) {
 716                *max_len = len;
 717                return  FILEID_INVALID;
 718        }
 719
 720        nodeid = get_fuse_inode(inode)->nodeid;
 721        generation = inode->i_generation;
 722
 723        fh[0] = (u32)(nodeid >> 32);
 724        fh[1] = (u32)(nodeid & 0xffffffff);
 725        fh[2] = generation;
 726
 727        if (parent) {
 728                nodeid = get_fuse_inode(parent)->nodeid;
 729                generation = parent->i_generation;
 730
 731                fh[3] = (u32)(nodeid >> 32);
 732                fh[4] = (u32)(nodeid & 0xffffffff);
 733                fh[5] = generation;
 734        }
 735
 736        *max_len = len;
 737        return parent ? 0x82 : 0x81;
 738}
 739
 740static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
 741                struct fid *fid, int fh_len, int fh_type)
 742{
 743        struct fuse_inode_handle handle;
 744
 745        if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
 746                return NULL;
 747
 748        handle.nodeid = (u64) fid->raw[0] << 32;
 749        handle.nodeid |= (u64) fid->raw[1];
 750        handle.generation = fid->raw[2];
 751        return fuse_get_dentry(sb, &handle);
 752}
 753
 754static struct dentry *fuse_fh_to_parent(struct super_block *sb,
 755                struct fid *fid, int fh_len, int fh_type)
 756{
 757        struct fuse_inode_handle parent;
 758
 759        if (fh_type != 0x82 || fh_len < 6)
 760                return NULL;
 761
 762        parent.nodeid = (u64) fid->raw[3] << 32;
 763        parent.nodeid |= (u64) fid->raw[4];
 764        parent.generation = fid->raw[5];
 765        return fuse_get_dentry(sb, &parent);
 766}
 767
 768static struct dentry *fuse_get_parent(struct dentry *child)
 769{
 770        struct inode *child_inode = d_inode(child);
 771        struct fuse_conn *fc = get_fuse_conn(child_inode);
 772        struct inode *inode;
 773        struct dentry *parent;
 774        struct fuse_entry_out outarg;
 775        const struct qstr name = QSTR_INIT("..", 2);
 776        int err;
 777
 778        if (!fc->export_support)
 779                return ERR_PTR(-ESTALE);
 780
 781        err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 782                               &name, &outarg, &inode);
 783        if (err) {
 784                if (err == -ENOENT)
 785                        return ERR_PTR(-ESTALE);
 786                return ERR_PTR(err);
 787        }
 788
 789        parent = d_obtain_alias(inode);
 790        if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
 791                fuse_invalidate_entry_cache(parent);
 792
 793        return parent;
 794}
 795
 796static const struct export_operations fuse_export_operations = {
 797        .fh_to_dentry   = fuse_fh_to_dentry,
 798        .fh_to_parent   = fuse_fh_to_parent,
 799        .encode_fh      = fuse_encode_fh,
 800        .get_parent     = fuse_get_parent,
 801};
 802
 803static const struct super_operations fuse_super_operations = {
 804        .alloc_inode    = fuse_alloc_inode,
 805        .destroy_inode  = fuse_destroy_inode,
 806        .evict_inode    = fuse_evict_inode,
 807        .write_inode    = fuse_write_inode,
 808        .drop_inode     = generic_delete_inode,
 809        .remount_fs     = fuse_remount_fs,
 810        .put_super      = fuse_put_super,
 811        .umount_begin   = fuse_umount_begin,
 812        .statfs         = fuse_statfs,
 813        .show_options   = fuse_show_options,
 814};
 815
 816static void sanitize_global_limit(unsigned *limit)
 817{
 818        if (*limit == 0)
 819                *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
 820                         sizeof(struct fuse_req);
 821
 822        if (*limit >= 1 << 16)
 823                *limit = (1 << 16) - 1;
 824}
 825
 826static int set_global_limit(const char *val, struct kernel_param *kp)
 827{
 828        int rv;
 829
 830        rv = param_set_uint(val, kp);
 831        if (rv)
 832                return rv;
 833
 834        sanitize_global_limit((unsigned *)kp->arg);
 835
 836        return 0;
 837}
 838
 839static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
 840{
 841        int cap_sys_admin = capable(CAP_SYS_ADMIN);
 842
 843        if (arg->minor < 13)
 844                return;
 845
 846        sanitize_global_limit(&max_user_bgreq);
 847        sanitize_global_limit(&max_user_congthresh);
 848
 849        if (arg->max_background) {
 850                fc->max_background = arg->max_background;
 851
 852                if (!cap_sys_admin && fc->max_background > max_user_bgreq)
 853                        fc->max_background = max_user_bgreq;
 854        }
 855        if (arg->congestion_threshold) {
 856                fc->congestion_threshold = arg->congestion_threshold;
 857
 858                if (!cap_sys_admin &&
 859                    fc->congestion_threshold > max_user_congthresh)
 860                        fc->congestion_threshold = max_user_congthresh;
 861        }
 862}
 863
 864static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 865{
 866        struct fuse_init_out *arg = &req->misc.init_out;
 867
 868        if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 869                fc->conn_error = 1;
 870        else {
 871                unsigned long ra_pages;
 872
 873                process_init_limits(fc, arg);
 874
 875                if (arg->minor >= 6) {
 876                        ra_pages = arg->max_readahead / PAGE_SIZE;
 877                        if (arg->flags & FUSE_ASYNC_READ)
 878                                fc->async_read = 1;
 879                        if (!(arg->flags & FUSE_POSIX_LOCKS))
 880                                fc->no_lock = 1;
 881                        if (arg->minor >= 17) {
 882                                if (!(arg->flags & FUSE_FLOCK_LOCKS))
 883                                        fc->no_flock = 1;
 884                        } else {
 885                                if (!(arg->flags & FUSE_POSIX_LOCKS))
 886                                        fc->no_flock = 1;
 887                        }
 888                        if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 889                                fc->atomic_o_trunc = 1;
 890                        if (arg->minor >= 9) {
 891                                /* LOOKUP has dependency on proto version */
 892                                if (arg->flags & FUSE_EXPORT_SUPPORT)
 893                                        fc->export_support = 1;
 894                        }
 895                        if (arg->flags & FUSE_BIG_WRITES)
 896                                fc->big_writes = 1;
 897                        if (arg->flags & FUSE_DONT_MASK)
 898                                fc->dont_mask = 1;
 899                        if (arg->flags & FUSE_AUTO_INVAL_DATA)
 900                                fc->auto_inval_data = 1;
 901                        if (arg->flags & FUSE_DO_READDIRPLUS) {
 902                                fc->do_readdirplus = 1;
 903                                if (arg->flags & FUSE_READDIRPLUS_AUTO)
 904                                        fc->readdirplus_auto = 1;
 905                        }
 906                        if (arg->flags & FUSE_ASYNC_DIO)
 907                                fc->async_dio = 1;
 908                        if (arg->flags & FUSE_WRITEBACK_CACHE)
 909                                fc->writeback_cache = 1;
 910                        if (arg->flags & FUSE_PARALLEL_DIROPS)
 911                                fc->parallel_dirops = 1;
 912                        if (arg->flags & FUSE_HANDLE_KILLPRIV)
 913                                fc->handle_killpriv = 1;
 914                        if (arg->time_gran && arg->time_gran <= 1000000000)
 915                                fc->sb->s_time_gran = arg->time_gran;
 916                        if ((arg->flags & FUSE_POSIX_ACL)) {
 917                                fc->default_permissions = 1;
 918                                fc->posix_acl = 1;
 919                                fc->sb->s_xattr = fuse_acl_xattr_handlers;
 920                        }
 921                } else {
 922                        ra_pages = fc->max_read / PAGE_SIZE;
 923                        fc->no_lock = 1;
 924                        fc->no_flock = 1;
 925                }
 926
 927                fc->sb->s_bdi->ra_pages =
 928                                min(fc->sb->s_bdi->ra_pages, ra_pages);
 929                fc->minor = arg->minor;
 930                fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 931                fc->max_write = max_t(unsigned, 4096, fc->max_write);
 932                fc->conn_init = 1;
 933        }
 934        fuse_set_initialized(fc);
 935        wake_up_all(&fc->blocked_waitq);
 936}
 937
 938static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 939{
 940        struct fuse_init_in *arg = &req->misc.init_in;
 941
 942        arg->major = FUSE_KERNEL_VERSION;
 943        arg->minor = FUSE_KERNEL_MINOR_VERSION;
 944        arg->max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE;
 945        arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 946                FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
 947                FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
 948                FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 949                FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 950                FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
 951                FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL;
 952        req->in.h.opcode = FUSE_INIT;
 953        req->in.numargs = 1;
 954        req->in.args[0].size = sizeof(*arg);
 955        req->in.args[0].value = arg;
 956        req->out.numargs = 1;
 957        /* Variable length argument used for backward compatibility
 958           with interface version < 7.5.  Rest of init_out is zeroed
 959           by do_get_request(), so a short reply is not a problem */
 960        req->out.argvar = 1;
 961        req->out.args[0].size = sizeof(struct fuse_init_out);
 962        req->out.args[0].value = &req->misc.init_out;
 963        req->end = process_init_reply;
 964        fuse_request_send_background(fc, req);
 965}
 966
 967static void fuse_free_conn(struct fuse_conn *fc)
 968{
 969        WARN_ON(!list_empty(&fc->devices));
 970        kfree_rcu(fc, rcu);
 971}
 972
 973static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 974{
 975        int err;
 976        char *suffix = "";
 977
 978        if (sb->s_bdev) {
 979                suffix = "-fuseblk";
 980                /*
 981                 * sb->s_bdi points to blkdev's bdi however we want to redirect
 982                 * it to our private bdi...
 983                 */
 984                bdi_put(sb->s_bdi);
 985                sb->s_bdi = &noop_backing_dev_info;
 986        }
 987        err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
 988                                   MINOR(fc->dev), suffix);
 989        if (err)
 990                return err;
 991
 992        sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
 993        /* fuse does it's own writeback accounting */
 994        sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 995
 996        /*
 997         * For a single fuse filesystem use max 1% of dirty +
 998         * writeback threshold.
 999         *
1000         * This gives about 1M of write buffer for memory maps on a
1001         * machine with 1G and 10% dirty_ratio, which should be more
1002         * than enough.
1003         *
1004         * Privileged users can raise it by writing to
1005         *
1006         *    /sys/class/bdi/<bdi>/max_ratio
1007         */
1008        bdi_set_max_ratio(sb->s_bdi, 1);
1009
1010        return 0;
1011}
1012
1013struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
1014{
1015        struct fuse_dev *fud;
1016
1017        fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1018        if (fud) {
1019                fud->fc = fuse_conn_get(fc);
1020                fuse_pqueue_init(&fud->pq);
1021
1022                spin_lock(&fc->lock);
1023                list_add_tail(&fud->entry, &fc->devices);
1024                spin_unlock(&fc->lock);
1025        }
1026
1027        return fud;
1028}
1029EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1030
1031void fuse_dev_free(struct fuse_dev *fud)
1032{
1033        struct fuse_conn *fc = fud->fc;
1034
1035        if (fc) {
1036                spin_lock(&fc->lock);
1037                list_del(&fud->entry);
1038                spin_unlock(&fc->lock);
1039
1040                fuse_conn_put(fc);
1041        }
1042        kfree(fud);
1043}
1044EXPORT_SYMBOL_GPL(fuse_dev_free);
1045
1046static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1047{
1048        struct fuse_dev *fud;
1049        struct fuse_conn *fc;
1050        struct inode *root;
1051        struct fuse_mount_data d;
1052        struct file *file;
1053        struct dentry *root_dentry;
1054        struct fuse_req *init_req;
1055        int err;
1056        int is_bdev = sb->s_bdev != NULL;
1057
1058        err = -EINVAL;
1059        if (sb->s_flags & MS_MANDLOCK)
1060                goto err;
1061
1062        sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1063
1064        if (!parse_fuse_opt(data, &d, is_bdev))
1065                goto err;
1066
1067        if (is_bdev) {
1068#ifdef CONFIG_BLOCK
1069                err = -EINVAL;
1070                if (!sb_set_blocksize(sb, d.blksize))
1071                        goto err;
1072#endif
1073        } else {
1074                sb->s_blocksize = PAGE_SIZE;
1075                sb->s_blocksize_bits = PAGE_SHIFT;
1076        }
1077        sb->s_magic = FUSE_SUPER_MAGIC;
1078        sb->s_op = &fuse_super_operations;
1079        sb->s_xattr = fuse_xattr_handlers;
1080        sb->s_maxbytes = MAX_LFS_FILESIZE;
1081        sb->s_time_gran = 1;
1082        sb->s_export_op = &fuse_export_operations;
1083
1084        file = fget(d.fd);
1085        err = -EINVAL;
1086        if (!file)
1087                goto err;
1088
1089        if ((file->f_op != &fuse_dev_operations) ||
1090            (file->f_cred->user_ns != &init_user_ns))
1091                goto err_fput;
1092
1093        fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1094        err = -ENOMEM;
1095        if (!fc)
1096                goto err_fput;
1097
1098        fuse_conn_init(fc);
1099        fc->release = fuse_free_conn;
1100
1101        fud = fuse_dev_alloc(fc);
1102        if (!fud)
1103                goto err_put_conn;
1104
1105        fc->dev = sb->s_dev;
1106        fc->sb = sb;
1107        err = fuse_bdi_init(fc, sb);
1108        if (err)
1109                goto err_dev_free;
1110
1111        /* Handle umasking inside the fuse code */
1112        if (sb->s_flags & MS_POSIXACL)
1113                fc->dont_mask = 1;
1114        sb->s_flags |= MS_POSIXACL;
1115
1116        fc->default_permissions = d.default_permissions;
1117        fc->allow_other = d.allow_other;
1118        fc->user_id = d.user_id;
1119        fc->group_id = d.group_id;
1120        fc->max_read = max_t(unsigned, 4096, d.max_read);
1121
1122        /* Used by get_root_inode() */
1123        sb->s_fs_info = fc;
1124
1125        err = -ENOMEM;
1126        root = fuse_get_root_inode(sb, d.rootmode);
1127        sb->s_d_op = &fuse_root_dentry_operations;
1128        root_dentry = d_make_root(root);
1129        if (!root_dentry)
1130                goto err_dev_free;
1131        /* Root dentry doesn't have .d_revalidate */
1132        sb->s_d_op = &fuse_dentry_operations;
1133
1134        init_req = fuse_request_alloc(0);
1135        if (!init_req)
1136                goto err_put_root;
1137        __set_bit(FR_BACKGROUND, &init_req->flags);
1138
1139        if (is_bdev) {
1140                fc->destroy_req = fuse_request_alloc(0);
1141                if (!fc->destroy_req)
1142                        goto err_free_init_req;
1143        }
1144
1145        mutex_lock(&fuse_mutex);
1146        err = -EINVAL;
1147        if (file->private_data)
1148                goto err_unlock;
1149
1150        err = fuse_ctl_add_conn(fc);
1151        if (err)
1152                goto err_unlock;
1153
1154        list_add_tail(&fc->entry, &fuse_conn_list);
1155        sb->s_root = root_dentry;
1156        file->private_data = fud;
1157        mutex_unlock(&fuse_mutex);
1158        /*
1159         * atomic_dec_and_test() in fput() provides the necessary
1160         * memory barrier for file->private_data to be visible on all
1161         * CPUs after this
1162         */
1163        fput(file);
1164
1165        fuse_send_init(fc, init_req);
1166
1167        return 0;
1168
1169 err_unlock:
1170        mutex_unlock(&fuse_mutex);
1171 err_free_init_req:
1172        fuse_request_free(init_req);
1173 err_put_root:
1174        dput(root_dentry);
1175 err_dev_free:
1176        fuse_dev_free(fud);
1177 err_put_conn:
1178        fuse_conn_put(fc);
1179 err_fput:
1180        fput(file);
1181 err:
1182        return err;
1183}
1184
1185static struct dentry *fuse_mount(struct file_system_type *fs_type,
1186                       int flags, const char *dev_name,
1187                       void *raw_data)
1188{
1189        return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1190}
1191
1192static void fuse_kill_sb_anon(struct super_block *sb)
1193{
1194        struct fuse_conn *fc = get_fuse_conn_super(sb);
1195
1196        if (fc) {
1197                down_write(&fc->killsb);
1198                fc->sb = NULL;
1199                up_write(&fc->killsb);
1200        }
1201
1202        kill_anon_super(sb);
1203}
1204
1205static struct file_system_type fuse_fs_type = {
1206        .owner          = THIS_MODULE,
1207        .name           = "fuse",
1208        .fs_flags       = FS_HAS_SUBTYPE,
1209        .mount          = fuse_mount,
1210        .kill_sb        = fuse_kill_sb_anon,
1211};
1212MODULE_ALIAS_FS("fuse");
1213
1214#ifdef CONFIG_BLOCK
1215static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1216                           int flags, const char *dev_name,
1217                           void *raw_data)
1218{
1219        return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1220}
1221
1222static void fuse_kill_sb_blk(struct super_block *sb)
1223{
1224        struct fuse_conn *fc = get_fuse_conn_super(sb);
1225
1226        if (fc) {
1227                down_write(&fc->killsb);
1228                fc->sb = NULL;
1229                up_write(&fc->killsb);
1230        }
1231
1232        kill_block_super(sb);
1233}
1234
1235static struct file_system_type fuseblk_fs_type = {
1236        .owner          = THIS_MODULE,
1237        .name           = "fuseblk",
1238        .mount          = fuse_mount_blk,
1239        .kill_sb        = fuse_kill_sb_blk,
1240        .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1241};
1242MODULE_ALIAS_FS("fuseblk");
1243
1244static inline int register_fuseblk(void)
1245{
1246        return register_filesystem(&fuseblk_fs_type);
1247}
1248
1249static inline void unregister_fuseblk(void)
1250{
1251        unregister_filesystem(&fuseblk_fs_type);
1252}
1253#else
1254static inline int register_fuseblk(void)
1255{
1256        return 0;
1257}
1258
1259static inline void unregister_fuseblk(void)
1260{
1261}
1262#endif
1263
1264static void fuse_inode_init_once(void *foo)
1265{
1266        struct inode *inode = foo;
1267
1268        inode_init_once(inode);
1269}
1270
1271static int __init fuse_fs_init(void)
1272{
1273        int err;
1274
1275        fuse_inode_cachep = kmem_cache_create("fuse_inode",
1276                                              sizeof(struct fuse_inode), 0,
1277                                              SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
1278                                              fuse_inode_init_once);
1279        err = -ENOMEM;
1280        if (!fuse_inode_cachep)
1281                goto out;
1282
1283        err = register_fuseblk();
1284        if (err)
1285                goto out2;
1286
1287        err = register_filesystem(&fuse_fs_type);
1288        if (err)
1289                goto out3;
1290
1291        return 0;
1292
1293 out3:
1294        unregister_fuseblk();
1295 out2:
1296        kmem_cache_destroy(fuse_inode_cachep);
1297 out:
1298        return err;
1299}
1300
1301static void fuse_fs_cleanup(void)
1302{
1303        unregister_filesystem(&fuse_fs_type);
1304        unregister_fuseblk();
1305
1306        /*
1307         * Make sure all delayed rcu free inodes are flushed before we
1308         * destroy cache.
1309         */
1310        rcu_barrier();
1311        kmem_cache_destroy(fuse_inode_cachep);
1312}
1313
1314static struct kobject *fuse_kobj;
1315
1316static int fuse_sysfs_init(void)
1317{
1318        int err;
1319
1320        fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1321        if (!fuse_kobj) {
1322                err = -ENOMEM;
1323                goto out_err;
1324        }
1325
1326        err = sysfs_create_mount_point(fuse_kobj, "connections");
1327        if (err)
1328                goto out_fuse_unregister;
1329
1330        return 0;
1331
1332 out_fuse_unregister:
1333        kobject_put(fuse_kobj);
1334 out_err:
1335        return err;
1336}
1337
1338static void fuse_sysfs_cleanup(void)
1339{
1340        sysfs_remove_mount_point(fuse_kobj, "connections");
1341        kobject_put(fuse_kobj);
1342}
1343
1344static int __init fuse_init(void)
1345{
1346        int res;
1347
1348        printk(KERN_INFO "fuse init (API version %i.%i)\n",
1349               FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1350
1351        INIT_LIST_HEAD(&fuse_conn_list);
1352        res = fuse_fs_init();
1353        if (res)
1354                goto err;
1355
1356        res = fuse_dev_init();
1357        if (res)
1358                goto err_fs_cleanup;
1359
1360        res = fuse_sysfs_init();
1361        if (res)
1362                goto err_dev_cleanup;
1363
1364        res = fuse_ctl_init();
1365        if (res)
1366                goto err_sysfs_cleanup;
1367
1368        sanitize_global_limit(&max_user_bgreq);
1369        sanitize_global_limit(&max_user_congthresh);
1370
1371        return 0;
1372
1373 err_sysfs_cleanup:
1374        fuse_sysfs_cleanup();
1375 err_dev_cleanup:
1376        fuse_dev_cleanup();
1377 err_fs_cleanup:
1378        fuse_fs_cleanup();
1379 err:
1380        return res;
1381}
1382
1383static void __exit fuse_exit(void)
1384{
1385        printk(KERN_DEBUG "fuse exit\n");
1386
1387        fuse_ctl_cleanup();
1388        fuse_sysfs_cleanup();
1389        fuse_fs_cleanup();
1390        fuse_dev_cleanup();
1391}
1392
1393module_init(fuse_init);
1394module_exit(fuse_exit);
1395