SAFE public projects git trees. - safe/jmp/linux-2.6/blob - fs/fuse/inode.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2006  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/parser.h>
  18 #include <linux/statfs.h>
  19 #include <linux/random.h>
  20 #include <linux/sched.h>
  21
  22 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  23 MODULE_DESCRIPTION("Filesystem in Userspace");
  24 MODULE_LICENSE("GPL");
  25
  26 static struct kmem_cache *fuse_inode_cachep;
  27 struct list_head fuse_conn_list;
  28 DEFINE_MUTEX(fuse_mutex);
  29
  30 #define FUSE_SUPER_MAGIC 0x65735546
  31
  32 struct fuse_mount_data {
  33         int fd;
  34         unsigned rootmode;
  35         unsigned user_id;
  36         unsigned group_id;
  37         unsigned fd_present : 1;
  38         unsigned rootmode_present : 1;
  39         unsigned user_id_present : 1;
  40         unsigned group_id_present : 1;
  41         unsigned flags;
  42         unsigned max_read;
  43         unsigned blksize;
  44 };
  45
  46 static struct inode *fuse_alloc_inode(struct super_block *sb)
  47 {
  48         struct inode *inode;
  49         struct fuse_inode *fi;
  50
  51         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  52         if (!inode)
  53                 return NULL;
  54
  55         fi = get_fuse_inode(inode);
  56         fi->i_time = 0;
  57         fi->nodeid = 0;
  58         fi->nlookup = 0;
  59         fi->attr_version = 0;
  60         INIT_LIST_HEAD(&fi->write_files);
  61         fi->forget_req = fuse_request_alloc();
  62         if (!fi->forget_req) {
  63                 kmem_cache_free(fuse_inode_cachep, inode);
  64                 return NULL;
  65         }
  66
  67         return inode;
  68 }
  69
  70 static void fuse_destroy_inode(struct inode *inode)
  71 {
  72         struct fuse_inode *fi = get_fuse_inode(inode);
  73         BUG_ON(!list_empty(&fi->write_files));
  74         if (fi->forget_req)
  75                 fuse_request_free(fi->forget_req);
  76         kmem_cache_free(fuse_inode_cachep, inode);
  77 }
  78
  79 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
  80                       unsigned long nodeid, u64 nlookup)
  81 {
  82         struct fuse_forget_in *inarg = &req->misc.forget_in;
  83         inarg->nlookup = nlookup;
  84         req->in.h.opcode = FUSE_FORGET;
  85         req->in.h.nodeid = nodeid;
  86         req->in.numargs = 1;
  87         req->in.args[0].size = sizeof(struct fuse_forget_in);
  88         req->in.args[0].value = inarg;
  89         request_send_noreply(fc, req);
  90 }
  91
  92 static void fuse_clear_inode(struct inode *inode)
  93 {
  94         if (inode->i_sb->s_flags & MS_ACTIVE) {
  95                 struct fuse_conn *fc = get_fuse_conn(inode);
  96                 struct fuse_inode *fi = get_fuse_inode(inode);
  97                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
  98                 fi->forget_req = NULL;
  99         }
 100 }
 101
 102 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 103 {
 104         if (*flags & MS_MANDLOCK)
 105                 return -EINVAL;
 106
 107         return 0;
 108 }
 109
 110 static void fuse_truncate(struct address_space *mapping, loff_t offset)
 111 {
 112         /* See vmtruncate() */
 113         unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
 114         truncate_inode_pages(mapping, offset);
 115         unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
 116 }
 117
 118
 119 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 120                             u64 attr_valid, u64 attr_version)
 121 {
 122         struct fuse_conn *fc = get_fuse_conn(inode);
 123         struct fuse_inode *fi = get_fuse_inode(inode);
 124         loff_t oldsize;
 125
 126         spin_lock(&fc->lock);
 127         if (attr_version != 0 && fi->attr_version > attr_version) {
 128                 spin_unlock(&fc->lock);
 129                 return;
 130         }
 131         fi->attr_version = ++fc->attr_version;
 132         fi->i_time = attr_valid;
 133
 134         inode->i_ino     = attr->ino;
 135         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 136         inode->i_nlink   = attr->nlink;
 137         inode->i_uid     = attr->uid;
 138         inode->i_gid     = attr->gid;
 139         inode->i_blocks  = attr->blocks;
 140         inode->i_atime.tv_sec   = attr->atime;
 141         inode->i_atime.tv_nsec  = attr->atimensec;
 142         inode->i_mtime.tv_sec   = attr->mtime;
 143         inode->i_mtime.tv_nsec  = attr->mtimensec;
 144         inode->i_ctime.tv_sec   = attr->ctime;
 145         inode->i_ctime.tv_nsec  = attr->ctimensec;
 146
 147         if (attr->blksize != 0)
 148                 inode->i_blkbits = ilog2(attr->blksize);
 149         else
 150                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 151
 152         /*
 153          * Don't set the sticky bit in i_mode, unless we want the VFS
 154          * to check permissions.  This prevents failures due to the
 155          * check in may_delete().
 156          */
 157         fi->orig_i_mode = inode->i_mode;
 158         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
 159                 inode->i_mode &= ~S_ISVTX;
 160
 161         oldsize = inode->i_size;
 162         i_size_write(inode, attr->size);
 163         spin_unlock(&fc->lock);
 164
 165         if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
 166                 if (attr->size < oldsize)
 167                         fuse_truncate(inode->i_mapping, attr->size);
 168                 invalidate_inode_pages2(inode->i_mapping);
 169         }
 170 }
 171
 172 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 173 {
 174         inode->i_mode = attr->mode & S_IFMT;
 175         inode->i_size = attr->size;
 176         if (S_ISREG(inode->i_mode)) {
 177                 fuse_init_common(inode);
 178                 fuse_init_file_inode(inode);
 179         } else if (S_ISDIR(inode->i_mode))
 180                 fuse_init_dir(inode);
 181         else if (S_ISLNK(inode->i_mode))
 182                 fuse_init_symlink(inode);
 183         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 184                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 185                 fuse_init_common(inode);
 186                 init_special_inode(inode, inode->i_mode,
 187                                    new_decode_dev(attr->rdev));
 188         } else
 189                 BUG();
 190 }
 191
 192 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 193 {
 194         unsigned long nodeid = *(unsigned long *) _nodeidp;
 195         if (get_node_id(inode) == nodeid)
 196                 return 1;
 197         else
 198                 return 0;
 199 }
 200
 201 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 202 {
 203         unsigned long nodeid = *(unsigned long *) _nodeidp;
 204         get_fuse_inode(inode)->nodeid = nodeid;
 205         return 0;
 206 }
 207
 208 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 209                         int generation, struct fuse_attr *attr,
 210                         u64 attr_valid, u64 attr_version)
 211 {
 212         struct inode *inode;
 213         struct fuse_inode *fi;
 214         struct fuse_conn *fc = get_fuse_conn_super(sb);
 215
 216  retry:
 217         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 218         if (!inode)
 219                 return NULL;
 220
 221         if ((inode->i_state & I_NEW)) {
 222                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 223                 inode->i_generation = generation;
 224                 inode->i_data.backing_dev_info = &fc->bdi;
 225                 fuse_init_inode(inode, attr);
 226                 unlock_new_inode(inode);
 227         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 228                 /* Inode has changed type, any I/O on the old should fail */
 229                 make_bad_inode(inode);
 230                 iput(inode);
 231                 goto retry;
 232         }
 233
 234         fi = get_fuse_inode(inode);
 235         spin_lock(&fc->lock);
 236         fi->nlookup ++;
 237         spin_unlock(&fc->lock);
 238         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 239
 240         return inode;
 241 }
 242
 243 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
 244 {
 245         if (flags & MNT_FORCE)
 246                 fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
 247 }
 248
 249 static void fuse_send_destroy(struct fuse_conn *fc)
 250 {
 251         struct fuse_req *req = fc->destroy_req;
 252         if (req && fc->conn_init) {
 253                 fc->destroy_req = NULL;
 254                 req->in.h.opcode = FUSE_DESTROY;
 255                 req->force = 1;
 256                 request_send(fc, req);
 257                 fuse_put_request(fc, req);
 258         }
 259 }
 260
 261 static void fuse_put_super(struct super_block *sb)
 262 {
 263         struct fuse_conn *fc = get_fuse_conn_super(sb);
 264
 265         fuse_send_destroy(fc);
 266         spin_lock(&fc->lock);
 267         fc->connected = 0;
 268         fc->blocked = 0;
 269         spin_unlock(&fc->lock);
 270         /* Flush all readers on this fs */
 271         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 272         wake_up_all(&fc->waitq);
 273         wake_up_all(&fc->blocked_waitq);
 274         wake_up_all(&fc->reserved_req_waitq);
 275         mutex_lock(&fuse_mutex);
 276         list_del(&fc->entry);
 277         fuse_ctl_remove_conn(fc);
 278         mutex_unlock(&fuse_mutex);
 279         fuse_conn_put(fc);
 280 }
 281
 282 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 283 {
 284         stbuf->f_type    = FUSE_SUPER_MAGIC;
 285         stbuf->f_bsize   = attr->bsize;
 286         stbuf->f_frsize  = attr->frsize;
 287         stbuf->f_blocks  = attr->blocks;
 288         stbuf->f_bfree   = attr->bfree;
 289         stbuf->f_bavail  = attr->bavail;
 290         stbuf->f_files   = attr->files;
 291         stbuf->f_ffree   = attr->ffree;
 292         stbuf->f_namelen = attr->namelen;
 293         /* fsid is left zero */
 294 }
 295
 296 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 297 {
 298         struct super_block *sb = dentry->d_sb;
 299         struct fuse_conn *fc = get_fuse_conn_super(sb);
 300         struct fuse_req *req;
 301         struct fuse_statfs_out outarg;
 302         int err;
 303
 304         if (!fuse_allow_task(fc, current)) {
 305                 buf->f_type = FUSE_SUPER_MAGIC;
 306                 return 0;
 307         }
 308
 309         req = fuse_get_req(fc);
 310         if (IS_ERR(req))
 311                 return PTR_ERR(req);
 312
 313         memset(&outarg, 0, sizeof(outarg));
 314         req->in.numargs = 0;
 315         req->in.h.opcode = FUSE_STATFS;
 316         req->in.h.nodeid = get_node_id(dentry->d_inode);
 317         req->out.numargs = 1;
 318         req->out.args[0].size =
 319                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 320         req->out.args[0].value = &outarg;
 321         request_send(fc, req);
 322         err = req->out.h.error;
 323         if (!err)
 324                 convert_fuse_statfs(buf, &outarg.st);
 325         fuse_put_request(fc, req);
 326         return err;
 327 }
 328
 329 enum {
 330         OPT_FD,
 331         OPT_ROOTMODE,
 332         OPT_USER_ID,
 333         OPT_GROUP_ID,
 334         OPT_DEFAULT_PERMISSIONS,
 335         OPT_ALLOW_OTHER,
 336         OPT_MAX_READ,
 337         OPT_BLKSIZE,
 338         OPT_ERR
 339 };
 340
 341 static match_table_t tokens = {
 342         {OPT_FD,                        "fd=%u"},
 343         {OPT_ROOTMODE,                  "rootmode=%o"},
 344         {OPT_USER_ID,                   "user_id=%u"},
 345         {OPT_GROUP_ID,                  "group_id=%u"},
 346         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 347         {OPT_ALLOW_OTHER,               "allow_other"},
 348         {OPT_MAX_READ,                  "max_read=%u"},
 349         {OPT_BLKSIZE,                   "blksize=%u"},
 350         {OPT_ERR,                       NULL}
 351 };
 352
 353 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 354 {
 355         char *p;
 356         memset(d, 0, sizeof(struct fuse_mount_data));
 357         d->max_read = ~0;
 358         d->blksize = 512;
 359
 360         while ((p = strsep(&opt, ",")) != NULL) {
 361                 int token;
 362                 int value;
 363                 substring_t args[MAX_OPT_ARGS];
 364                 if (!*p)
 365                         continue;
 366
 367                 token = match_token(p, tokens, args);
 368                 switch (token) {
 369                 case OPT_FD:
 370                         if (match_int(&args[0], &value))
 371                                 return 0;
 372                         d->fd = value;
 373                         d->fd_present = 1;
 374                         break;
 375
 376                 case OPT_ROOTMODE:
 377                         if (match_octal(&args[0], &value))
 378                                 return 0;
 379                         if (!fuse_valid_type(value))
 380                                 return 0;
 381                         d->rootmode = value;
 382                         d->rootmode_present = 1;
 383                         break;
 384
 385                 case OPT_USER_ID:
 386                         if (match_int(&args[0], &value))
 387                                 return 0;
 388                         d->user_id = value;
 389                         d->user_id_present = 1;
 390                         break;
 391
 392                 case OPT_GROUP_ID:
 393                         if (match_int(&args[0], &value))
 394                                 return 0;
 395                         d->group_id = value;
 396                         d->group_id_present = 1;
 397                         break;
 398
 399                 case OPT_DEFAULT_PERMISSIONS:
 400                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 401                         break;
 402
 403                 case OPT_ALLOW_OTHER:
 404                         d->flags |= FUSE_ALLOW_OTHER;
 405                         break;
 406
 407                 case OPT_MAX_READ:
 408                         if (match_int(&args[0], &value))
 409                                 return 0;
 410                         d->max_read = value;
 411                         break;
 412
 413                 case OPT_BLKSIZE:
 414                         if (!is_bdev || match_int(&args[0], &value))
 415                                 return 0;
 416                         d->blksize = value;
 417                         break;
 418
 419                 default:
 420                         return 0;
 421                 }
 422         }
 423
 424         if (!d->fd_present || !d->rootmode_present ||
 425             !d->user_id_present || !d->group_id_present)
 426                 return 0;
 427
 428         return 1;
 429 }
 430
 431 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 432 {
 433         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 434
 435         seq_printf(m, ",user_id=%u", fc->user_id);
 436         seq_printf(m, ",group_id=%u", fc->group_id);
 437         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 438                 seq_puts(m, ",default_permissions");
 439         if (fc->flags & FUSE_ALLOW_OTHER)
 440                 seq_puts(m, ",allow_other");
 441         if (fc->max_read != ~0)
 442                 seq_printf(m, ",max_read=%u", fc->max_read);
 443         return 0;
 444 }
 445
 446 static struct fuse_conn *new_conn(void)
 447 {
 448         struct fuse_conn *fc;
 449         int err;
 450
 451         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 452         if (fc) {
 453                 spin_lock_init(&fc->lock);
 454                 mutex_init(&fc->inst_mutex);
 455                 atomic_set(&fc->count, 1);
 456                 init_waitqueue_head(&fc->waitq);
 457                 init_waitqueue_head(&fc->blocked_waitq);
 458                 init_waitqueue_head(&fc->reserved_req_waitq);
 459                 INIT_LIST_HEAD(&fc->pending);
 460                 INIT_LIST_HEAD(&fc->processing);
 461                 INIT_LIST_HEAD(&fc->io);
 462                 INIT_LIST_HEAD(&fc->interrupts);
 463                 INIT_LIST_HEAD(&fc->bg_queue);
 464                 atomic_set(&fc->num_waiting, 0);
 465                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 466                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 467                 err = bdi_init(&fc->bdi);
 468                 if (err) {
 469                         kfree(fc);
 470                         fc = NULL;
 471                         goto out;
 472                 }
 473                 fc->reqctr = 0;
 474                 fc->blocked = 1;
 475                 fc->attr_version = 1;
 476                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 477         }
 478 out:
 479         return fc;
 480 }
 481
 482 void fuse_conn_put(struct fuse_conn *fc)
 483 {
 484         if (atomic_dec_and_test(&fc->count)) {
 485                 if (fc->destroy_req)
 486                         fuse_request_free(fc->destroy_req);
 487                 mutex_destroy(&fc->inst_mutex);
 488                 bdi_destroy(&fc->bdi);
 489                 kfree(fc);
 490         }
 491 }
 492
 493 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 494 {
 495         atomic_inc(&fc->count);
 496         return fc;
 497 }
 498
 499 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 500 {
 501         struct fuse_attr attr;
 502         memset(&attr, 0, sizeof(attr));
 503
 504         attr.mode = mode;
 505         attr.ino = FUSE_ROOT_ID;
 506         attr.nlink = 1;
 507         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 508 }
 509
 510 static const struct super_operations fuse_super_operations = {
 511         .alloc_inode    = fuse_alloc_inode,
 512         .destroy_inode  = fuse_destroy_inode,
 513         .clear_inode    = fuse_clear_inode,
 514         .drop_inode     = generic_delete_inode,
 515         .remount_fs     = fuse_remount_fs,
 516         .put_super      = fuse_put_super,
 517         .umount_begin   = fuse_umount_begin,
 518         .statfs         = fuse_statfs,
 519         .show_options   = fuse_show_options,
 520 };
 521
 522 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 523 {
 524         struct fuse_init_out *arg = &req->misc.init_out;
 525
 526         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 527                 fc->conn_error = 1;
 528         else {
 529                 unsigned long ra_pages;
 530
 531                 if (arg->minor >= 6) {
 532                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 533                         if (arg->flags & FUSE_ASYNC_READ)
 534                                 fc->async_read = 1;
 535                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 536                                 fc->no_lock = 1;
 537                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 538                                 fc->atomic_o_trunc = 1;
 539                 } else {
 540                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 541                         fc->no_lock = 1;
 542                 }
 543
 544                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 545                 fc->minor = arg->minor;
 546                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 547                 fc->conn_init = 1;
 548         }
 549         fuse_put_request(fc, req);
 550         fc->blocked = 0;
 551         wake_up_all(&fc->blocked_waitq);
 552 }
 553
 554 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 555 {
 556         struct fuse_init_in *arg = &req->misc.init_in;
 557
 558         arg->major = FUSE_KERNEL_VERSION;
 559         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 560         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 561         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC;
 562         req->in.h.opcode = FUSE_INIT;
 563         req->in.numargs = 1;
 564         req->in.args[0].size = sizeof(*arg);
 565         req->in.args[0].value = arg;
 566         req->out.numargs = 1;
 567         /* Variable length arguement used for backward compatibility
 568            with interface version < 7.5.  Rest of init_out is zeroed
 569            by do_get_request(), so a short reply is not a problem */
 570         req->out.argvar = 1;
 571         req->out.args[0].size = sizeof(struct fuse_init_out);
 572         req->out.args[0].value = &req->misc.init_out;
 573         req->end = process_init_reply;
 574         request_send_background(fc, req);
 575 }
 576
 577 static u64 conn_id(void)
 578 {
 579         static u64 ctr = 1;
 580         return ctr++;
 581 }
 582
 583 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 584 {
 585         struct fuse_conn *fc;
 586         struct inode *root;
 587         struct fuse_mount_data d;
 588         struct file *file;
 589         struct dentry *root_dentry;
 590         struct fuse_req *init_req;
 591         int err;
 592         int is_bdev = sb->s_bdev != NULL;
 593
 594         if (sb->s_flags & MS_MANDLOCK)
 595                 return -EINVAL;
 596
 597         if (!parse_fuse_opt((char *) data, &d, is_bdev))
 598                 return -EINVAL;
 599
 600         if (is_bdev) {
 601 #ifdef CONFIG_BLOCK
 602                 if (!sb_set_blocksize(sb, d.blksize))
 603                         return -EINVAL;
 604 #endif
 605         } else {
 606                 sb->s_blocksize = PAGE_CACHE_SIZE;
 607                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 608         }
 609         sb->s_magic = FUSE_SUPER_MAGIC;
 610         sb->s_op = &fuse_super_operations;
 611         sb->s_maxbytes = MAX_LFS_FILESIZE;
 612
 613         file = fget(d.fd);
 614         if (!file)
 615                 return -EINVAL;
 616
 617         if (file->f_op != &fuse_dev_operations)
 618                 return -EINVAL;
 619
 620         fc = new_conn();
 621         if (!fc)
 622                 return -ENOMEM;
 623
 624         fc->flags = d.flags;
 625         fc->user_id = d.user_id;
 626         fc->group_id = d.group_id;
 627         fc->max_read = d.max_read;
 628
 629         /* Used by get_root_inode() */
 630         sb->s_fs_info = fc;
 631
 632         err = -ENOMEM;
 633         root = get_root_inode(sb, d.rootmode);
 634         if (!root)
 635                 goto err;
 636
 637         root_dentry = d_alloc_root(root);
 638         if (!root_dentry) {
 639                 iput(root);
 640                 goto err;
 641         }
 642
 643         init_req = fuse_request_alloc();
 644         if (!init_req)
 645                 goto err_put_root;
 646
 647         if (is_bdev) {
 648                 fc->destroy_req = fuse_request_alloc();
 649                 if (!fc->destroy_req)
 650                         goto err_put_root;
 651         }
 652
 653         mutex_lock(&fuse_mutex);
 654         err = -EINVAL;
 655         if (file->private_data)
 656                 goto err_unlock;
 657
 658         fc->id = conn_id();
 659         err = fuse_ctl_add_conn(fc);
 660         if (err)
 661                 goto err_unlock;
 662
 663         list_add_tail(&fc->entry, &fuse_conn_list);
 664         sb->s_root = root_dentry;
 665         fc->connected = 1;
 666         file->private_data = fuse_conn_get(fc);
 667         mutex_unlock(&fuse_mutex);
 668         /*
 669          * atomic_dec_and_test() in fput() provides the necessary
 670          * memory barrier for file->private_data to be visible on all
 671          * CPUs after this
 672          */
 673         fput(file);
 674
 675         fuse_send_init(fc, init_req);
 676
 677         return 0;
 678
 679  err_unlock:
 680         mutex_unlock(&fuse_mutex);
 681         fuse_request_free(init_req);
 682  err_put_root:
 683         dput(root_dentry);
 684  err:
 685         fput(file);
 686         fuse_conn_put(fc);
 687         return err;
 688 }
 689
 690 static int fuse_get_sb(struct file_system_type *fs_type,
 691                        int flags, const char *dev_name,
 692                        void *raw_data, struct vfsmount *mnt)
 693 {
 694         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 695 }
 696
 697 static struct file_system_type fuse_fs_type = {
 698         .owner          = THIS_MODULE,
 699         .name           = "fuse",
 700         .fs_flags       = FS_HAS_SUBTYPE,
 701         .get_sb         = fuse_get_sb,
 702         .kill_sb        = kill_anon_super,
 703 };
 704
 705 #ifdef CONFIG_BLOCK
 706 static int fuse_get_sb_blk(struct file_system_type *fs_type,
 707                            int flags, const char *dev_name,
 708                            void *raw_data, struct vfsmount *mnt)
 709 {
 710         return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
 711                            mnt);
 712 }
 713
 714 static struct file_system_type fuseblk_fs_type = {
 715         .owner          = THIS_MODULE,
 716         .name           = "fuseblk",
 717         .get_sb         = fuse_get_sb_blk,
 718         .kill_sb        = kill_block_super,
 719         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
 720 };
 721
 722 static inline int register_fuseblk(void)
 723 {
 724         return register_filesystem(&fuseblk_fs_type);
 725 }
 726
 727 static inline void unregister_fuseblk(void)
 728 {
 729         unregister_filesystem(&fuseblk_fs_type);
 730 }
 731 #else
 732 static inline int register_fuseblk(void)
 733 {
 734         return 0;
 735 }
 736
 737 static inline void unregister_fuseblk(void)
 738 {
 739 }
 740 #endif
 741
 742 static void fuse_inode_init_once(struct kmem_cache *cachep, void *foo)
 743 {
 744         struct inode * inode = foo;
 745
 746         inode_init_once(inode);
 747 }
 748
 749 static int __init fuse_fs_init(void)
 750 {
 751         int err;
 752
 753         err = register_filesystem(&fuse_fs_type);
 754         if (err)
 755                 goto out;
 756
 757         err = register_fuseblk();
 758         if (err)
 759                 goto out_unreg;
 760
 761         fuse_inode_cachep = kmem_cache_create("fuse_inode",
 762                                               sizeof(struct fuse_inode),
 763                                               0, SLAB_HWCACHE_ALIGN,
 764                                               fuse_inode_init_once);
 765         err = -ENOMEM;
 766         if (!fuse_inode_cachep)
 767                 goto out_unreg2;
 768
 769         return 0;
 770
 771  out_unreg2:
 772         unregister_fuseblk();
 773  out_unreg:
 774         unregister_filesystem(&fuse_fs_type);
 775  out:
 776         return err;
 777 }
 778
 779 static void fuse_fs_cleanup(void)
 780 {
 781         unregister_filesystem(&fuse_fs_type);
 782         unregister_fuseblk();
 783         kmem_cache_destroy(fuse_inode_cachep);
 784 }
 785
 786 static struct kobject *fuse_kobj;
 787 static struct kobject *connections_kobj;
 788
 789 static int fuse_sysfs_init(void)
 790 {
 791         int err;
 792
 793         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
 794         if (!fuse_kobj) {
 795                 err = -ENOMEM;
 796                 goto out_err;
 797         }
 798
 799         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
 800         if (!connections_kobj) {
 801                 err = -ENOMEM;
 802                 goto out_fuse_unregister;
 803         }
 804
 805         return 0;
 806
 807  out_fuse_unregister:
 808         kobject_put(fuse_kobj);
 809  out_err:
 810         return err;
 811 }
 812
 813 static void fuse_sysfs_cleanup(void)
 814 {
 815         kobject_put(connections_kobj);
 816         kobject_put(fuse_kobj);
 817 }
 818
 819 static int __init fuse_init(void)
 820 {
 821         int res;
 822
 823         printk("fuse init (API version %i.%i)\n",
 824                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 825
 826         INIT_LIST_HEAD(&fuse_conn_list);
 827         res = fuse_fs_init();
 828         if (res)
 829                 goto err;
 830
 831         res = fuse_dev_init();
 832         if (res)
 833                 goto err_fs_cleanup;
 834
 835         res = fuse_sysfs_init();
 836         if (res)
 837                 goto err_dev_cleanup;
 838
 839         res = fuse_ctl_init();
 840         if (res)
 841                 goto err_sysfs_cleanup;
 842
 843         return 0;
 844
 845  err_sysfs_cleanup:
 846         fuse_sysfs_cleanup();
 847  err_dev_cleanup:
 848         fuse_dev_cleanup();
 849  err_fs_cleanup:
 850         fuse_fs_cleanup();
 851  err:
 852         return res;
 853 }
 854
 855 static void __exit fuse_exit(void)
 856 {
 857         printk(KERN_DEBUG "fuse exit\n");
 858
 859         fuse_ctl_cleanup();
 860         fuse_sysfs_cleanup();
 861         fuse_fs_cleanup();
 862         fuse_dev_cleanup();
 863 }
 864
 865 module_init(fuse_init);
 866 module_exit(fuse_exit);