fs/fuse/dir.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2008  Miklos Szeredi <[email protected]>
   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/file.h>
  13 #include <linux/sched.h>
  14 #include <linux/namei.h>
  15 #include <linux/slab.h>
  16
  17 static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx)
  18 {
  19         struct fuse_conn *fc = get_fuse_conn(dir);
  20         struct fuse_inode *fi = get_fuse_inode(dir);
  21
  22         if (!fc->do_readdirplus)
  23                 return false;
  24         if (!fc->readdirplus_auto)
  25                 return true;
  26         if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
  27                 return true;
  28         if (ctx->pos == 0)
  29                 return true;
  30         return false;
  31 }
  32
  33 static void fuse_advise_use_readdirplus(struct inode *dir)
  34 {
  35         struct fuse_inode *fi = get_fuse_inode(dir);
  36
  37         set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
  38 }
  39
  40 #if BITS_PER_LONG >= 64
  41 static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
  42 {
  43         entry->d_time = time;
  44 }
  45
  46 static inline u64 fuse_dentry_time(struct dentry *entry)
  47 {
  48         return entry->d_time;
  49 }
  50 #else
  51 /*
  52  * On 32 bit archs store the high 32 bits of time in d_fsdata
  53  */
  54 static void fuse_dentry_settime(struct dentry *entry, u64 time)
  55 {
  56         entry->d_time = time;
  57         entry->d_fsdata = (void *) (unsigned long) (time >> 32);
  58 }
  59
  60 static u64 fuse_dentry_time(struct dentry *entry)
  61 {
  62         return (u64) entry->d_time +
  63                 ((u64) (unsigned long) entry->d_fsdata << 32);
  64 }
  65 #endif
  66
  67 /*
  68  * FUSE caches dentries and attributes with separate timeout.  The
  69  * time in jiffies until the dentry/attributes are valid is stored in
  70  * dentry->d_time and fuse_inode->i_time respectively.
  71  */
  72
  73 /*
  74  * Calculate the time in jiffies until a dentry/attributes are valid
  75  */
  76 static u64 time_to_jiffies(unsigned long sec, unsigned long nsec)
  77 {
  78         if (sec || nsec) {
  79                 struct timespec ts = {sec, nsec};
  80                 return get_jiffies_64() + timespec_to_jiffies(&ts);
  81         } else
  82                 return 0;
  83 }
  84
  85 /*
  86  * Set dentry and possibly attribute timeouts from the lookup/mk*
  87  * replies
  88  */
  89 static void fuse_change_entry_timeout(struct dentry *entry,
  90                                       struct fuse_entry_out *o)
  91 {
  92         fuse_dentry_settime(entry,
  93                 time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
  94 }
  95
  96 static u64 attr_timeout(struct fuse_attr_out *o)
  97 {
  98         return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
  99 }
 100
 101 static u64 entry_attr_timeout(struct fuse_entry_out *o)
 102 {
 103         return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
 104 }
 105
 106 /*
 107  * Mark the attributes as stale, so that at the next call to
 108  * ->getattr() they will be fetched from userspace
 109  */
 110 void fuse_invalidate_attr(struct inode *inode)
 111 {
 112         get_fuse_inode(inode)->i_time = 0;
 113 }
 114
 115 /**
 116  * Mark the attributes as stale due to an atime change.  Avoid the invalidate if
 117  * atime is not used.
 118  */
 119 void fuse_invalidate_atime(struct inode *inode)
 120 {
 121         if (!IS_RDONLY(inode))
 122                 fuse_invalidate_attr(inode);
 123 }
 124
 125 /*
 126  * Just mark the entry as stale, so that a next attempt to look it up
 127  * will result in a new lookup call to userspace
 128  *
 129  * This is called when a dentry is about to become negative and the
 130  * timeout is unknown (unlink, rmdir, rename and in some cases
 131  * lookup)
 132  */
 133 void fuse_invalidate_entry_cache(struct dentry *entry)
 134 {
 135         fuse_dentry_settime(entry, 0);
 136 }
 137
 138 /*
 139  * Same as fuse_invalidate_entry_cache(), but also try to remove the
 140  * dentry from the hash
 141  */
 142 static void fuse_invalidate_entry(struct dentry *entry)
 143 {
 144         d_invalidate(entry);
 145         fuse_invalidate_entry_cache(entry);
 146 }
 147
 148 static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_req *req,
 149                              u64 nodeid, struct qstr *name,
 150                              struct fuse_entry_out *outarg)
 151 {
 152         memset(outarg, 0, sizeof(struct fuse_entry_out));
 153         req->in.h.opcode = FUSE_LOOKUP;
 154         req->in.h.nodeid = nodeid;
 155         req->in.numargs = 1;
 156         req->in.args[0].size = name->len + 1;
 157         req->in.args[0].value = name->name;
 158         req->out.numargs = 1;
 159         if (fc->minor < 9)
 160                 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
 161         else
 162                 req->out.args[0].size = sizeof(struct fuse_entry_out);
 163         req->out.args[0].value = outarg;
 164 }
 165
 166 u64 fuse_get_attr_version(struct fuse_conn *fc)
 167 {
 168         u64 curr_version;
 169
 170         /*
 171          * The spin lock isn't actually needed on 64bit archs, but we
 172          * don't yet care too much about such optimizations.
 173          */
 174         spin_lock(&fc->lock);
 175         curr_version = fc->attr_version;
 176         spin_unlock(&fc->lock);
 177
 178         return curr_version;
 179 }
 180
 181 /*
 182  * Check whether the dentry is still valid
 183  *
 184  * If the entry validity timeout has expired and the dentry is
 185  * positive, try to redo the lookup.  If the lookup results in a
 186  * different inode, then let the VFS invalidate the dentry and redo
 187  * the lookup once more.  If the lookup results in the same inode,
 188  * then refresh the attributes, timeouts and mark the dentry valid.
 189  */
 190 static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 191 {
 192         struct inode *inode;
 193         struct dentry *parent;
 194         struct fuse_conn *fc;
 195         struct fuse_inode *fi;
 196         int ret;
 197
 198         inode = ACCESS_ONCE(entry->d_inode);
 199         if (inode && is_bad_inode(inode))
 200                 goto invalid;
 201         else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
 202                  (flags & LOOKUP_REVAL)) {
 203                 int err;
 204                 struct fuse_entry_out outarg;
 205                 struct fuse_req *req;
 206                 struct fuse_forget_link *forget;
 207                 u64 attr_version;
 208
 209                 /* For negative dentries, always do a fresh lookup */
 210                 if (!inode)
 211                         goto invalid;
 212
 213                 ret = -ECHILD;
 214                 if (flags & LOOKUP_RCU)
 215                         goto out;
 216
 217                 fc = get_fuse_conn(inode);
 218                 req = fuse_get_req_nopages(fc);
 219                 ret = PTR_ERR(req);
 220                 if (IS_ERR(req))
 221                         goto out;
 222
 223                 forget = fuse_alloc_forget();
 224                 if (!forget) {
 225                         fuse_put_request(fc, req);
 226                         ret = -ENOMEM;
 227                         goto out;
 228                 }
 229
 230                 attr_version = fuse_get_attr_version(fc);
 231
 232                 parent = dget_parent(entry);
 233                 fuse_lookup_init(fc, req, get_node_id(parent->d_inode),
 234                                  &entry->d_name, &outarg);
 235                 fuse_request_send(fc, req);
 236                 dput(parent);
 237                 err = req->out.h.error;
 238                 fuse_put_request(fc, req);
 239                 /* Zero nodeid is same as -ENOENT */
 240                 if (!err && !outarg.nodeid)
 241                         err = -ENOENT;
 242                 if (!err) {
 243                         fi = get_fuse_inode(inode);
 244                         if (outarg.nodeid != get_node_id(inode)) {
 245                                 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
 246                                 goto invalid;
 247                         }
 248                         spin_lock(&fc->lock);
 249                         fi->nlookup++;
 250                         spin_unlock(&fc->lock);
 251                 }
 252                 kfree(forget);
 253                 if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
 254                         goto invalid;
 255
 256                 fuse_change_attributes(inode, &outarg.attr,
 257                                        entry_attr_timeout(&outarg),
 258                                        attr_version);
 259                 fuse_change_entry_timeout(entry, &outarg);
 260         } else if (inode) {
 261                 fi = get_fuse_inode(inode);
 262                 if (flags & LOOKUP_RCU) {
 263                         if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state))
 264                                 return -ECHILD;
 265                 } else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) {
 266                         parent = dget_parent(entry);
 267                         fuse_advise_use_readdirplus(parent->d_inode);
 268                         dput(parent);
 269                 }
 270         }
 271         ret = 1;
 272 out:
 273         return ret;
 274
 275 invalid:
 276         ret = 0;
 277
 278         if (!(flags & LOOKUP_RCU) && check_submounts_and_drop(entry) != 0)
 279                 ret = 1;
 280         goto out;
 281 }
 282
 283 static int invalid_nodeid(u64 nodeid)
 284 {
 285         return !nodeid || nodeid == FUSE_ROOT_ID;
 286 }
 287
 288 const struct dentry_operations fuse_dentry_operations = {
 289         .d_revalidate   = fuse_dentry_revalidate,
 290 };
 291
 292 int fuse_valid_type(int m)
 293 {
 294         return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
 295                 S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
 296 }
 297
 298 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 299                      struct fuse_entry_out *outarg, struct inode **inode)
 300 {
 301         struct fuse_conn *fc = get_fuse_conn_super(sb);
 302         struct fuse_req *req;
 303         struct fuse_forget_link *forget;
 304         u64 attr_version;
 305         int err;
 306
 307         *inode = NULL;
 308         err = -ENAMETOOLONG;
 309         if (name->len > FUSE_NAME_MAX)
 310                 goto out;
 311
 312         req = fuse_get_req_nopages(fc);
 313         err = PTR_ERR(req);
 314         if (IS_ERR(req))
 315                 goto out;
 316
 317         forget = fuse_alloc_forget();
 318         err = -ENOMEM;
 319         if (!forget) {
 320                 fuse_put_request(fc, req);
 321                 goto out;
 322         }
 323
 324         attr_version = fuse_get_attr_version(fc);
 325
 326         fuse_lookup_init(fc, req, nodeid, name, outarg);
 327         fuse_request_send(fc, req);
 328         err = req->out.h.error;
 329         fuse_put_request(fc, req);
 330         /* Zero nodeid is same as -ENOENT, but with valid timeout */
 331         if (err || !outarg->nodeid)
 332                 goto out_put_forget;
 333
 334         err = -EIO;
 335         if (!outarg->nodeid)
 336                 goto out_put_forget;
 337         if (!fuse_valid_type(outarg->attr.mode))
 338                 goto out_put_forget;
 339
 340         *inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
 341                            &outarg->attr, entry_attr_timeout(outarg),
 342                            attr_version);
 343         err = -ENOMEM;
 344         if (!*inode) {
 345                 fuse_queue_forget(fc, forget, outarg->nodeid, 1);
 346                 goto out;
 347         }
 348         err = 0;
 349
 350  out_put_forget:
 351         kfree(forget);
 352  out:
 353         return err;
 354 }
 355
 356 static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
 357                                   unsigned int flags)
 358 {
 359         int err;
 360         struct fuse_entry_out outarg;
 361         struct inode *inode;
 362         struct dentry *newent;
 363         bool outarg_valid = true;
 364
 365         err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
 366                                &outarg, &inode);
 367         if (err == -ENOENT) {
 368                 outarg_valid = false;
 369                 err = 0;
 370         }
 371         if (err)
 372                 goto out_err;
 373
 374         err = -EIO;
 375         if (inode && get_node_id(inode) == FUSE_ROOT_ID)
 376                 goto out_iput;
 377
 378         newent = d_materialise_unique(entry, inode);
 379         err = PTR_ERR(newent);
 380         if (IS_ERR(newent))
 381                 goto out_err;
 382
 383         entry = newent ? newent : entry;
 384         if (outarg_valid)
 385                 fuse_change_entry_timeout(entry, &outarg);
 386         else
 387                 fuse_invalidate_entry_cache(entry);
 388
 389         fuse_advise_use_readdirplus(dir);
 390         return newent;
 391
 392  out_iput:
 393         iput(inode);
 394  out_err:
 395         return ERR_PTR(err);
 396 }
 397
 398 /*
 399  * Atomic create+open operation
 400  *
 401  * If the filesystem doesn't support this, then fall back to separate
 402  * 'mknod' + 'open' requests.
 403  */
 404 static int fuse_create_open(struct inode *dir, struct dentry *entry,
 405                             struct file *file, unsigned flags,
 406                             umode_t mode, int *opened)
 407 {
 408         int err;
 409         struct inode *inode;
 410         struct fuse_conn *fc = get_fuse_conn(dir);
 411         struct fuse_req *req;
 412         struct fuse_forget_link *forget;
 413         struct fuse_create_in inarg;
 414         struct fuse_open_out outopen;
 415         struct fuse_entry_out outentry;
 416         struct fuse_file *ff;
 417
 418         /* Userspace expects S_IFREG in create mode */
 419         BUG_ON((mode & S_IFMT) != S_IFREG);
 420
 421         forget = fuse_alloc_forget();
 422         err = -ENOMEM;
 423         if (!forget)
 424                 goto out_err;
 425
 426         req = fuse_get_req_nopages(fc);
 427         err = PTR_ERR(req);
 428         if (IS_ERR(req))
 429                 goto out_put_forget_req;
 430
 431         err = -ENOMEM;
 432         ff = fuse_file_alloc(fc);
 433         if (!ff)
 434                 goto out_put_request;
 435
 436         if (!fc->dont_mask)
 437                 mode &= ~current_umask();
 438
 439         flags &= ~O_NOCTTY;
 440         memset(&inarg, 0, sizeof(inarg));
 441         memset(&outentry, 0, sizeof(outentry));
 442         inarg.flags = flags;
 443         inarg.mode = mode;
 444         inarg.umask = current_umask();
 445         req->in.h.opcode = FUSE_CREATE;
 446         req->in.h.nodeid = get_node_id(dir);
 447         req->in.numargs = 2;
 448         req->in.args[0].size = fc->minor < 12 ? sizeof(struct fuse_open_in) :
 449                                                 sizeof(inarg);
 450         req->in.args[0].value = &inarg;
 451         req->in.args[1].size = entry->d_name.len + 1;
 452         req->in.args[1].value = entry->d_name.name;
 453         req->out.numargs = 2;
 454         if (fc->minor < 9)
 455                 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
 456         else
 457                 req->out.args[0].size = sizeof(outentry);
 458         req->out.args[0].value = &outentry;
 459         req->out.args[1].size = sizeof(outopen);
 460         req->out.args[1].value = &outopen;
 461         fuse_request_send(fc, req);
 462         err = req->out.h.error;
 463         if (err)
 464                 goto out_free_ff;
 465
 466         err = -EIO;
 467         if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
 468                 goto out_free_ff;
 469
 470         fuse_put_request(fc, req);
 471         ff->fh = outopen.fh;
 472         ff->nodeid = outentry.nodeid;
 473         ff->open_flags = outopen.open_flags;
 474         inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
 475                           &outentry.attr, entry_attr_timeout(&outentry), 0);
 476         if (!inode) {
 477                 flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
 478                 fuse_sync_release(ff, flags);
 479                 fuse_queue_forget(fc, forget, outentry.nodeid, 1);
 480                 err = -ENOMEM;
 481                 goto out_err;
 482         }
 483         kfree(forget);
 484         d_instantiate(entry, inode);
 485         fuse_change_entry_timeout(entry, &outentry);
 486         fuse_invalidate_attr(dir);
 487         err = finish_open(file, entry, generic_file_open, opened);
 488         if (err) {
 489                 fuse_sync_release(ff, flags);
 490         } else {
 491                 file->private_data = fuse_file_get(ff);
 492                 fuse_finish_open(inode, file);
 493         }
 494         return err;
 495
 496 out_free_ff:
 497         fuse_file_free(ff);
 498 out_put_request:
 499         fuse_put_request(fc, req);
 500 out_put_forget_req:
 501         kfree(forget);
 502 out_err:
 503         return err;
 504 }
 505
 506 static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t);
 507 static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
 508                             struct file *file, unsigned flags,
 509                             umode_t mode, int *opened)
 510 {
 511         int err;
 512         struct fuse_conn *fc = get_fuse_conn(dir);
 513         struct dentry *res = NULL;
 514
 515         if (d_unhashed(entry)) {
 516                 res = fuse_lookup(dir, entry, 0);
 517                 if (IS_ERR(res))
 518                         return PTR_ERR(res);
 519
 520                 if (res)
 521                         entry = res;
 522         }
 523
 524         if (!(flags & O_CREAT) || entry->d_inode)
 525                 goto no_open;
 526
 527         /* Only creates */
 528         *opened |= FILE_CREATED;
 529
 530         if (fc->no_create)
 531                 goto mknod;
 532
 533         err = fuse_create_open(dir, entry, file, flags, mode, opened);
 534         if (err == -ENOSYS) {
 535                 fc->no_create = 1;
 536                 goto mknod;
 537         }
 538 out_dput:
 539         dput(res);
 540         return err;
 541
 542 mknod:
 543         err = fuse_mknod(dir, entry, mode, 0);
 544         if (err)
 545                 goto out_dput;
 546 no_open:
 547         return finish_no_open(file, res);
 548 }
 549
 550 /*
 551  * Code shared between mknod, mkdir, symlink and link
 552  */
 553 static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
 554                             struct inode *dir, struct dentry *entry,
 555                             umode_t mode)
 556 {
 557         struct fuse_entry_out outarg;
 558         struct inode *inode;
 559         int err;
 560         struct fuse_forget_link *forget;
 561
 562         forget = fuse_alloc_forget();
 563         if (!forget) {
 564                 fuse_put_request(fc, req);
 565                 return -ENOMEM;
 566         }
 567
 568         memset(&outarg, 0, sizeof(outarg));
 569         req->in.h.nodeid = get_node_id(dir);
 570         req->out.numargs = 1;
 571         if (fc->minor < 9)
 572                 req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
 573         else
 574                 req->out.args[0].size = sizeof(outarg);
 575         req->out.args[0].value = &outarg;
 576         fuse_request_send(fc, req);
 577         err = req->out.h.error;
 578         fuse_put_request(fc, req);
 579         if (err)
 580                 goto out_put_forget_req;
 581
 582         err = -EIO;
 583         if (invalid_nodeid(outarg.nodeid))
 584                 goto out_put_forget_req;
 585
 586         if ((outarg.attr.mode ^ mode) & S_IFMT)
 587                 goto out_put_forget_req;
 588
 589         inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
 590                           &outarg.attr, entry_attr_timeout(&outarg), 0);
 591         if (!inode) {
 592                 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
 593                 return -ENOMEM;
 594         }
 595         kfree(forget);
 596
 597         err = d_instantiate_no_diralias(entry, inode);
 598         if (err)
 599                 return err;
 600
 601         fuse_change_entry_timeout(entry, &outarg);
 602         fuse_invalidate_attr(dir);
 603         return 0;
 604
 605  out_put_forget_req:
 606         kfree(forget);
 607         return err;
 608 }
 609
 610 static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode,
 611                       dev_t rdev)
 612 {
 613         struct fuse_mknod_in inarg;
 614         struct fuse_conn *fc = get_fuse_conn(dir);
 615         struct fuse_req *req = fuse_get_req_nopages(fc);
 616         if (IS_ERR(req))
 617                 return PTR_ERR(req);
 618
 619         if (!fc->dont_mask)
 620                 mode &= ~current_umask();
 621
 622         memset(&inarg, 0, sizeof(inarg));
 623         inarg.mode = mode;
 624         inarg.rdev = new_encode_dev(rdev);
 625         inarg.umask = current_umask();
 626         req->in.h.opcode = FUSE_MKNOD;
 627         req->in.numargs = 2;
 628         req->in.args[0].size = fc->minor < 12 ? FUSE_COMPAT_MKNOD_IN_SIZE :
 629                                                 sizeof(inarg);
 630         req->in.args[0].value = &inarg;
 631         req->in.args[1].size = entry->d_name.len + 1;
 632         req->in.args[1].value = entry->d_name.name;
 633         return create_new_entry(fc, req, dir, entry, mode);
 634 }
 635
 636 static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,
 637                        bool excl)
 638 {
 639         return fuse_mknod(dir, entry, mode, 0);
 640 }
 641
 642 static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode)
 643 {
 644         struct fuse_mkdir_in inarg;
 645         struct fuse_conn *fc = get_fuse_conn(dir);
 646         struct fuse_req *req = fuse_get_req_nopages(fc);
 647         if (IS_ERR(req))
 648                 return PTR_ERR(req);
 649
 650         if (!fc->dont_mask)
 651                 mode &= ~current_umask();
 652
 653         memset(&inarg, 0, sizeof(inarg));
 654         inarg.mode = mode;
 655         inarg.umask = current_umask();
 656         req->in.h.opcode = FUSE_MKDIR;
 657         req->in.numargs = 2;
 658         req->in.args[0].size = sizeof(inarg);
 659         req->in.args[0].value = &inarg;
 660         req->in.args[1].size = entry->d_name.len + 1;
 661         req->in.args[1].value = entry->d_name.name;
 662         return create_new_entry(fc, req, dir, entry, S_IFDIR);
 663 }
 664
 665 static int fuse_symlink(struct inode *dir, struct dentry *entry,
 666                         const char *link)
 667 {
 668         struct fuse_conn *fc = get_fuse_conn(dir);
 669         unsigned len = strlen(link) + 1;
 670         struct fuse_req *req = fuse_get_req_nopages(fc);
 671         if (IS_ERR(req))
 672                 return PTR_ERR(req);
 673
 674         req->in.h.opcode = FUSE_SYMLINK;
 675         req->in.numargs = 2;
 676         req->in.args[0].size = entry->d_name.len + 1;
 677         req->in.args[0].value = entry->d_name.name;
 678         req->in.args[1].size = len;
 679         req->in.args[1].value = link;
 680         return create_new_entry(fc, req, dir, entry, S_IFLNK);
 681 }
 682
 683 static inline void fuse_update_ctime(struct inode *inode)
 684 {
 685         if (!IS_NOCMTIME(inode)) {
 686                 inode->i_ctime = current_fs_time(inode->i_sb);
 687                 mark_inode_dirty_sync(inode);
 688         }
 689 }
 690
 691 static int fuse_unlink(struct inode *dir, struct dentry *entry)
 692 {
 693         int err;
 694         struct fuse_conn *fc = get_fuse_conn(dir);
 695         struct fuse_req *req = fuse_get_req_nopages(fc);
 696         if (IS_ERR(req))
 697                 return PTR_ERR(req);
 698
 699         req->in.h.opcode = FUSE_UNLINK;
 700         req->in.h.nodeid = get_node_id(dir);
 701         req->in.numargs = 1;
 702         req->in.args[0].size = entry->d_name.len + 1;
 703         req->in.args[0].value = entry->d_name.name;
 704         fuse_request_send(fc, req);
 705         err = req->out.h.error;
 706         fuse_put_request(fc, req);
 707         if (!err) {
 708                 struct inode *inode = entry->d_inode;
 709                 struct fuse_inode *fi = get_fuse_inode(inode);
 710
 711                 spin_lock(&fc->lock);
 712                 fi->attr_version = ++fc->attr_version;
 713                 /*
 714                  * If i_nlink == 0 then unlink doesn't make sense, yet this can
 715                  * happen if userspace filesystem is careless.  It would be
 716                  * difficult to enforce correct nlink usage so just ignore this
 717                  * condition here
 718                  */
 719                 if (inode->i_nlink > 0)
 720                         drop_nlink(inode);
 721                 spin_unlock(&fc->lock);
 722                 fuse_invalidate_attr(inode);
 723                 fuse_invalidate_attr(dir);
 724                 fuse_invalidate_entry_cache(entry);
 725                 fuse_update_ctime(inode);
 726         } else if (err == -EINTR)
 727                 fuse_invalidate_entry(entry);
 728         return err;
 729 }
 730
 731 static int fuse_rmdir(struct inode *dir, struct dentry *entry)
 732 {
 733         int err;
 734         struct fuse_conn *fc = get_fuse_conn(dir);
 735         struct fuse_req *req = fuse_get_req_nopages(fc);
 736         if (IS_ERR(req))
 737                 return PTR_ERR(req);
 738
 739         req->in.h.opcode = FUSE_RMDIR;
 740         req->in.h.nodeid = get_node_id(dir);
 741         req->in.numargs = 1;
 742         req->in.args[0].size = entry->d_name.len + 1;
 743         req->in.args[0].value = entry->d_name.name;
 744         fuse_request_send(fc, req);
 745         err = req->out.h.error;
 746         fuse_put_request(fc, req);
 747         if (!err) {
 748                 clear_nlink(entry->d_inode);
 749                 fuse_invalidate_attr(dir);
 750                 fuse_invalidate_entry_cache(entry);
 751         } else if (err == -EINTR)
 752                 fuse_invalidate_entry(entry);
 753         return err;
 754 }
 755
 756 static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
 757                               struct inode *newdir, struct dentry *newent,
 758                               unsigned int flags, int opcode, size_t argsize)
 759 {
 760         int err;
 761         struct fuse_rename2_in inarg;
 762         struct fuse_conn *fc = get_fuse_conn(olddir);
 763         struct fuse_req *req;
 764
 765         req = fuse_get_req_nopages(fc);
 766         if (IS_ERR(req))
 767                 return PTR_ERR(req);
 768
 769         memset(&inarg, 0, argsize);
 770         inarg.newdir = get_node_id(newdir);
 771         inarg.flags = flags;
 772         req->in.h.opcode = opcode;
 773         req->in.h.nodeid = get_node_id(olddir);
 774         req->in.numargs = 3;
 775         req->in.args[0].size = argsize;
 776         req->in.args[0].value = &inarg;
 777         req->in.args[1].size = oldent->d_name.len + 1;
 778         req->in.args[1].value = oldent->d_name.name;
 779         req->in.args[2].size = newent->d_name.len + 1;
 780         req->in.args[2].value = newent->d_name.name;
 781         fuse_request_send(fc, req);
 782         err = req->out.h.error;
 783         fuse_put_request(fc, req);
 784         if (!err) {
 785                 /* ctime changes */
 786                 fuse_invalidate_attr(oldent->d_inode);
 787                 fuse_update_ctime(oldent->d_inode);
 788
 789                 if (flags & RENAME_EXCHANGE) {
 790                         fuse_invalidate_attr(newent->d_inode);
 791                         fuse_update_ctime(newent->d_inode);
 792                 }
 793
 794                 fuse_invalidate_attr(olddir);
 795                 if (olddir != newdir)
 796                         fuse_invalidate_attr(newdir);
 797
 798                 /* newent will end up negative */
 799                 if (!(flags & RENAME_EXCHANGE) && newent->d_inode) {
 800                         fuse_invalidate_attr(newent->d_inode);
 801                         fuse_invalidate_entry_cache(newent);
 802                         fuse_update_ctime(newent->d_inode);
 803                 }
 804         } else if (err == -EINTR) {
 805                 /* If request was interrupted, DEITY only knows if the
 806                    rename actually took place.  If the invalidation
 807                    fails (e.g. some process has CWD under the renamed
 808                    directory), then there can be inconsistency between
 809                    the dcache and the real filesystem.  Tough luck. */
 810                 fuse_invalidate_entry(oldent);
 811                 if (newent->d_inode)
 812                         fuse_invalidate_entry(newent);
 813         }
 814
 815         return err;
 816 }
 817
 818 static int fuse_rename2(struct inode *olddir, struct dentry *oldent,
 819                         struct inode *newdir, struct dentry *newent,
 820                         unsigned int flags)
 821 {
 822         struct fuse_conn *fc = get_fuse_conn(olddir);
 823         int err;
 824
 825         if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
 826                 return -EINVAL;
 827
 828         if (flags) {
 829                 if (fc->no_rename2 || fc->minor < 23)
 830                         return -EINVAL;
 831
 832                 err = fuse_rename_common(olddir, oldent, newdir, newent, flags,
 833                                          FUSE_RENAME2,
 834                                          sizeof(struct fuse_rename2_in));
 835                 if (err == -ENOSYS) {
 836                         fc->no_rename2 = 1;
 837                         err = -EINVAL;
 838                 }
 839         } else {
 840                 err = fuse_rename_common(olddir, oldent, newdir, newent, 0,
 841                                          FUSE_RENAME,
 842                                          sizeof(struct fuse_rename_in));
 843         }
 844
 845         return err;
 846 }
 847
 848 static int fuse_rename(struct inode *olddir, struct dentry *oldent,
 849                        struct inode *newdir, struct dentry *newent)
 850 {
 851         return fuse_rename2(olddir, oldent, newdir, newent, 0);
 852 }
 853
 854 static int fuse_link(struct dentry *entry, struct inode *newdir,
 855                      struct dentry *newent)
 856 {
 857         int err;
 858         struct fuse_link_in inarg;
 859         struct inode *inode = entry->d_inode;
 860         struct fuse_conn *fc = get_fuse_conn(inode);
 861         struct fuse_req *req = fuse_get_req_nopages(fc);
 862         if (IS_ERR(req))
 863                 return PTR_ERR(req);
 864
 865         memset(&inarg, 0, sizeof(inarg));
 866         inarg.oldnodeid = get_node_id(inode);
 867         req->in.h.opcode = FUSE_LINK;
 868         req->in.numargs = 2;
 869         req->in.args[0].size = sizeof(inarg);
 870         req->in.args[0].value = &inarg;
 871         req->in.args[1].size = newent->d_name.len + 1;
 872         req->in.args[1].value = newent->d_name.name;
 873         err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
 874         /* Contrary to "normal" filesystems it can happen that link
 875            makes two "logical" inodes point to the same "physical"
 876            inode.  We invalidate the attributes of the old one, so it
 877            will reflect changes in the backing inode (link count,
 878            etc.)
 879         */
 880         if (!err) {
 881                 struct fuse_inode *fi = get_fuse_inode(inode);
 882
 883                 spin_lock(&fc->lock);
 884                 fi->attr_version = ++fc->attr_version;
 885                 inc_nlink(inode);
 886                 spin_unlock(&fc->lock);
 887                 fuse_invalidate_attr(inode);
 888                 fuse_update_ctime(inode);
 889         } else if (err == -EINTR) {
 890                 fuse_invalidate_attr(inode);
 891         }
 892         return err;
 893 }
 894
 895 static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
 896                           struct kstat *stat)
 897 {
 898         unsigned int blkbits;
 899         struct fuse_conn *fc = get_fuse_conn(inode);
 900
 901         /* see the comment in fuse_change_attributes() */
 902         if (fc->writeback_cache && S_ISREG(inode->i_mode)) {
 903                 attr->size = i_size_read(inode);
 904                 attr->mtime = inode->i_mtime.tv_sec;
 905                 attr->mtimensec = inode->i_mtime.tv_nsec;
 906                 attr->ctime = inode->i_ctime.tv_sec;
 907                 attr->ctimensec = inode->i_ctime.tv_nsec;
 908         }
 909
 910         stat->dev = inode->i_sb->s_dev;
 911         stat->ino = attr->ino;
 912         stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 913         stat->nlink = attr->nlink;
 914         stat->uid = make_kuid(&init_user_ns, attr->uid);
 915         stat->gid = make_kgid(&init_user_ns, attr->gid);
 916         stat->rdev = inode->i_rdev;
 917         stat->atime.tv_sec = attr->atime;
 918         stat->atime.tv_nsec = attr->atimensec;
 919         stat->mtime.tv_sec = attr->mtime;
 920         stat->mtime.tv_nsec = attr->mtimensec;
 921         stat->ctime.tv_sec = attr->ctime;
 922         stat->ctime.tv_nsec = attr->ctimensec;
 923         stat->size = attr->size;
 924         stat->blocks = attr->blocks;
 925
 926         if (attr->blksize != 0)
 927                 blkbits = ilog2(attr->blksize);
 928         else
 929                 blkbits = inode->i_sb->s_blocksize_bits;
 930
 931         stat->blksize = 1 << blkbits;
 932 }
 933
 934 static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
 935                            struct file *file)
 936 {
 937         int err;
 938         struct fuse_getattr_in inarg;
 939         struct fuse_attr_out outarg;
 940         struct fuse_conn *fc = get_fuse_conn(inode);
 941         struct fuse_req *req;
 942         u64 attr_version;
 943
 944         req = fuse_get_req_nopages(fc);
 945         if (IS_ERR(req))
 946                 return PTR_ERR(req);
 947
 948         attr_version = fuse_get_attr_version(fc);
 949
 950         memset(&inarg, 0, sizeof(inarg));
 951         memset(&outarg, 0, sizeof(outarg));
 952         /* Directories have separate file-handle space */
 953         if (file && S_ISREG(inode->i_mode)) {
 954                 struct fuse_file *ff = file->private_data;
 955
 956                 inarg.getattr_flags |= FUSE_GETATTR_FH;
 957                 inarg.fh = ff->fh;
 958         }
 959         req->in.h.opcode = FUSE_GETATTR;
 960         req->in.h.nodeid = get_node_id(inode);
 961         req->in.numargs = 1;
 962         req->in.args[0].size = sizeof(inarg);
 963         req->in.args[0].value = &inarg;
 964         req->out.numargs = 1;
 965         if (fc->minor < 9)
 966                 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
 967         else
 968                 req->out.args[0].size = sizeof(outarg);
 969         req->out.args[0].value = &outarg;
 970         fuse_request_send(fc, req);
 971         err = req->out.h.error;
 972         fuse_put_request(fc, req);
 973         if (!err) {
 974                 if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
 975                         make_bad_inode(inode);
 976                         err = -EIO;
 977                 } else {
 978                         fuse_change_attributes(inode, &outarg.attr,
 979                                                attr_timeout(&outarg),
 980                                                attr_version);
 981                         if (stat)
 982                                 fuse_fillattr(inode, &outarg.attr, stat);
 983                 }
 984         }
 985         return err;
 986 }
 987
 988 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 989                            struct file *file, bool *refreshed)
 990 {
 991         struct fuse_inode *fi = get_fuse_inode(inode);
 992         int err;
 993         bool r;
 994
 995         if (time_before64(fi->i_time, get_jiffies_64())) {
 996                 r = true;
 997                 err = fuse_do_getattr(inode, stat, file);
 998         } else {
 999                 r = false;
1000                 err = 0;
1001                 if (stat) {
1002                         generic_fillattr(inode, stat);
1003                         stat->mode = fi->orig_i_mode;
1004                         stat->ino = fi->orig_ino;
1005                 }
1006         }
1007
1008         if (refreshed != NULL)
1009                 *refreshed = r;
1010
1011         return err;
1012 }
1013
1014 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
1015                              u64 child_nodeid, struct qstr *name)
1016 {
1017         int err = -ENOTDIR;
1018         struct inode *parent;
1019         struct dentry *dir;
1020         struct dentry *entry;
1021
1022         parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
1023         if (!parent)
1024                 return -ENOENT;
1025
1026         mutex_lock(&parent->i_mutex);
1027         if (!S_ISDIR(parent->i_mode))
1028                 goto unlock;
1029
1030         err = -ENOENT;
1031         dir = d_find_alias(parent);
1032         if (!dir)
1033                 goto unlock;
1034
1035         entry = d_lookup(dir, name);
1036         dput(dir);
1037         if (!entry)
1038                 goto unlock;
1039
1040         fuse_invalidate_attr(parent);
1041         fuse_invalidate_entry(entry);
1042
1043         if (child_nodeid != 0 && entry->d_inode) {
1044                 mutex_lock(&entry->d_inode->i_mutex);
1045                 if (get_node_id(entry->d_inode) != child_nodeid) {
1046                         err = -ENOENT;
1047                         goto badentry;
1048                 }
1049                 if (d_mountpoint(entry)) {
1050                         err = -EBUSY;
1051                         goto badentry;
1052                 }
1053                 if (S_ISDIR(entry->d_inode->i_mode)) {
1054                         shrink_dcache_parent(entry);
1055                         if (!simple_empty(entry)) {
1056                                 err = -ENOTEMPTY;
1057                                 goto badentry;
1058                         }
1059                         entry->d_inode->i_flags |= S_DEAD;
1060                 }
1061                 dont_mount(entry);
1062                 clear_nlink(entry->d_inode);
1063                 err = 0;
1064  badentry:
1065                 mutex_unlock(&entry->d_inode->i_mutex);
1066                 if (!err)
1067                         d_delete(entry);
1068         } else {
1069                 err = 0;
1070         }
1071         dput(entry);
1072
1073  unlock:
1074         mutex_unlock(&parent->i_mutex);
1075         iput(parent);
1076         return err;
1077 }
1078
1079 /*
1080  * Calling into a user-controlled filesystem gives the filesystem
1081  * daemon ptrace-like capabilities over the current process.  This
1082  * means, that the filesystem daemon is able to record the exact
1083  * filesystem operations performed, and can also control the behavior
1084  * of the requester process in otherwise impossible ways.  For example
1085  * it can delay the operation for arbitrary length of time allowing
1086  * DoS against the requester.
1087  *
1088  * For this reason only those processes can call into the filesystem,
1089  * for which the owner of the mount has ptrace privilege.  This
1090  * excludes processes started by other users, suid or sgid processes.
1091  */
1092 int fuse_allow_current_process(struct fuse_conn *fc)
1093 {
1094         const struct cred *cred;
1095
1096         if (fc->flags & FUSE_ALLOW_OTHER)
1097                 return 1;
1098
1099         cred = current_cred();
1100         if (uid_eq(cred->euid, fc->user_id) &&
1101             uid_eq(cred->suid, fc->user_id) &&
1102             uid_eq(cred->uid,  fc->user_id) &&
1103             gid_eq(cred->egid, fc->group_id) &&
1104             gid_eq(cred->sgid, fc->group_id) &&
1105             gid_eq(cred->gid,  fc->group_id))
1106                 return 1;
1107
1108         return 0;
1109 }
1110
1111 static int fuse_access(struct inode *inode, int mask)
1112 {
1113         struct fuse_conn *fc = get_fuse_conn(inode);
1114         struct fuse_req *req;
1115         struct fuse_access_in inarg;
1116         int err;
1117
1118         BUG_ON(mask & MAY_NOT_BLOCK);
1119
1120         if (fc->no_access)
1121                 return 0;
1122
1123         req = fuse_get_req_nopages(fc);
1124         if (IS_ERR(req))
1125                 return PTR_ERR(req);
1126
1127         memset(&inarg, 0, sizeof(inarg));
1128         inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
1129         req->in.h.opcode = FUSE_ACCESS;
1130         req->in.h.nodeid = get_node_id(inode);
1131         req->in.numargs = 1;
1132         req->in.args[0].size = sizeof(inarg);
1133         req->in.args[0].value = &inarg;
1134         fuse_request_send(fc, req);
1135         err = req->out.h.error;
1136         fuse_put_request(fc, req);
1137         if (err == -ENOSYS) {
1138                 fc->no_access = 1;
1139                 err = 0;
1140         }
1141         return err;
1142 }
1143
1144 static int fuse_perm_getattr(struct inode *inode, int mask)
1145 {
1146         if (mask & MAY_NOT_BLOCK)
1147                 return -ECHILD;
1148
1149         return fuse_do_getattr(inode, NULL, NULL);
1150 }
1151
1152 /*
1153  * Check permission.  The two basic access models of FUSE are:
1154  *
1155  * 1) Local access checking ('default_permissions' mount option) based
1156  * on file mode.  This is the plain old disk filesystem permission
1157  * modell.
1158  *
1159  * 2) "Remote" access checking, where server is responsible for
1160  * checking permission in each inode operation.  An exception to this
1161  * is if ->permission() was invoked from sys_access() in which case an
1162  * access request is sent.  Execute permission is still checked
1163  * locally based on file mode.
1164  */
1165 static int fuse_permission(struct inode *inode, int mask)
1166 {
1167         struct fuse_conn *fc = get_fuse_conn(inode);
1168         bool refreshed = false;
1169         int err = 0;
1170
1171         if (!fuse_allow_current_process(fc))
1172                 return -EACCES;
1173
1174         /*
1175          * If attributes are needed, refresh them before proceeding
1176          */
1177         if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) ||
1178             ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
1179                 struct fuse_inode *fi = get_fuse_inode(inode);
1180
1181                 if (time_before64(fi->i_time, get_jiffies_64())) {
1182                         refreshed = true;
1183
1184                         err = fuse_perm_getattr(inode, mask);
1185                         if (err)
1186                                 return err;
1187                 }
1188         }
1189
1190         if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
1191                 err = generic_permission(inode, mask);
1192
1193                 /* If permission is denied, try to refresh file
1194                    attributes.  This is also needed, because the root
1195                    node will at first have no permissions */
1196                 if (err == -EACCES && !refreshed) {
1197                         err = fuse_perm_getattr(inode, mask);
1198                         if (!err)
1199                                 err = generic_permission(inode, mask);
1200                 }
1201
1202                 /* Note: the opposite of the above test does not
1203                    exist.  So if permissions are revoked this won't be
1204                    noticed immediately, only after the attribute
1205                    timeout has expired */
1206         } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
1207                 err = fuse_access(inode, mask);
1208         } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
1209                 if (!(inode->i_mode & S_IXUGO)) {
1210                         if (refreshed)
1211                                 return -EACCES;
1212
1213                         err = fuse_perm_getattr(inode, mask);
1214                         if (!err && !(inode->i_mode & S_IXUGO))
1215                                 return -EACCES;
1216                 }
1217         }
1218         return err;
1219 }
1220
1221 static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
1222                          struct dir_context *ctx)
1223 {
1224         while (nbytes >= FUSE_NAME_OFFSET) {
1225                 struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
1226                 size_t reclen = FUSE_DIRENT_SIZE(dirent);
1227                 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
1228                         return -EIO;
1229                 if (reclen > nbytes)
1230                         break;
1231                 if (memchr(dirent->name, '/', dirent->namelen) != NULL)
1232                         return -EIO;
1233
1234                 if (!dir_emit(ctx, dirent->name, dirent->namelen,
1235                                dirent->ino, dirent->type))
1236                         break;
1237
1238                 buf += reclen;
1239                 nbytes -= reclen;
1240                 ctx->pos = dirent->off;
1241         }
1242
1243         return 0;
1244 }
1245
1246 static int fuse_direntplus_link(struct file *file,
1247                                 struct fuse_direntplus *direntplus,
1248                                 u64 attr_version)
1249 {
1250         int err;
1251         struct fuse_entry_out *o = &direntplus->entry_out;
1252         struct fuse_dirent *dirent = &direntplus->dirent;
1253         struct dentry *parent = file->f_path.dentry;
1254         struct qstr name = QSTR_INIT(dirent->name, dirent->namelen);
1255         struct dentry *dentry;
1256         struct dentry *alias;
1257         struct inode *dir = parent->d_inode;
1258         struct fuse_conn *fc;
1259         struct inode *inode;
1260
1261         if (!o->nodeid) {
1262                 /*
1263                  * Unlike in the case of fuse_lookup, zero nodeid does not mean
1264                  * ENOENT. Instead, it only means the userspace filesystem did
1265                  * not want to return attributes/handle for this entry.
1266                  *
1267                  * So do nothing.
1268                  */
1269                 return 0;
1270         }
1271
1272         if (name.name[0] == '.') {
1273                 /*
1274                  * We could potentially refresh the attributes of the directory
1275                  * and its parent?
1276                  */
1277                 if (name.len == 1)
1278                         return 0;
1279                 if (name.name[1] == '.' && name.len == 2)
1280                         return 0;
1281         }
1282
1283         if (invalid_nodeid(o->nodeid))
1284                 return -EIO;
1285         if (!fuse_valid_type(o->attr.mode))
1286                 return -EIO;
1287
1288         fc = get_fuse_conn(dir);
1289
1290         name.hash = full_name_hash(name.name, name.len);
1291         dentry = d_lookup(parent, &name);
1292         if (dentry) {
1293                 inode = dentry->d_inode;
1294                 if (!inode) {
1295                         d_drop(dentry);
1296                 } else if (get_node_id(inode) != o->nodeid ||
1297                            ((o->attr.mode ^ inode->i_mode) & S_IFMT)) {
1298                         err = d_invalidate(dentry);
1299                         if (err)
1300                                 goto out;
1301                 } else if (is_bad_inode(inode)) {
1302                         err = -EIO;
1303                         goto out;
1304                 } else {
1305                         struct fuse_inode *fi;
1306                         fi = get_fuse_inode(inode);
1307                         spin_lock(&fc->lock);
1308                         fi->nlookup++;
1309                         spin_unlock(&fc->lock);
1310
1311                         fuse_change_attributes(inode, &o->attr,
1312                                                entry_attr_timeout(o),
1313                                                attr_version);
1314
1315                         /*
1316                          * The other branch to 'found' comes via fuse_iget()
1317                          * which bumps nlookup inside
1318                          */
1319                         goto found;
1320                 }
1321                 dput(dentry);
1322         }
1323
1324         dentry = d_alloc(parent, &name);
1325         err = -ENOMEM;
1326         if (!dentry)
1327                 goto out;
1328
1329         inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
1330                           &o->attr, entry_attr_timeout(o), attr_version);
1331         if (!inode)
1332                 goto out;
1333
1334         alias = d_materialise_unique(dentry, inode);
1335         err = PTR_ERR(alias);
1336         if (IS_ERR(alias))
1337                 goto out;
1338
1339         if (alias) {
1340                 dput(dentry);
1341                 dentry = alias;
1342         }
1343
1344 found:
1345         if (fc->readdirplus_auto)
1346                 set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);
1347         fuse_change_entry_timeout(dentry, o);
1348
1349         err = 0;
1350 out:
1351         dput(dentry);
1352         return err;
1353 }
1354
1355 static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
1356                              struct dir_context *ctx, u64 attr_version)
1357 {
1358         struct fuse_direntplus *direntplus;
1359         struct fuse_dirent *dirent;
1360         size_t reclen;
1361         int over = 0;
1362         int ret;
1363
1364         while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) {
1365                 direntplus = (struct fuse_direntplus *) buf;
1366                 dirent = &direntplus->dirent;
1367                 reclen = FUSE_DIRENTPLUS_SIZE(direntplus);
1368
1369                 if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
1370                         return -EIO;
1371                 if (reclen > nbytes)
1372                         break;
1373                 if (memchr(dirent->name, '/', dirent->namelen) != NULL)
1374                         return -EIO;
1375
1376                 if (!over) {
1377                         /* We fill entries into dstbuf only as much as
1378                            it can hold. But we still continue iterating
1379                            over remaining entries to link them. If not,
1380                            we need to send a FORGET for each of those
1381                            which we did not link.
1382                         */
1383                         over = !dir_emit(ctx, dirent->name, dirent->namelen,
1384                                        dirent->ino, dirent->type);
1385                         ctx->pos = dirent->off;
1386                 }
1387
1388                 buf += reclen;
1389                 nbytes -= reclen;
1390
1391                 ret = fuse_direntplus_link(file, direntplus, attr_version);
1392                 if (ret)
1393                         fuse_force_forget(file, direntplus->entry_out.nodeid);
1394         }
1395
1396         return 0;
1397 }
1398
1399 static int fuse_readdir(struct file *file, struct dir_context *ctx)
1400 {
1401         int plus, err;
1402         size_t nbytes;
1403         struct page *page;
1404         struct inode *inode = file_inode(file);
1405         struct fuse_conn *fc = get_fuse_conn(inode);
1406         struct fuse_req *req;
1407         u64 attr_version = 0;
1408
1409         if (is_bad_inode(inode))
1410                 return -EIO;
1411
1412         req = fuse_get_req(fc, 1);
1413         if (IS_ERR(req))
1414                 return PTR_ERR(req);
1415
1416         page = alloc_page(GFP_KERNEL);
1417         if (!page) {
1418                 fuse_put_request(fc, req);
1419                 return -ENOMEM;
1420         }
1421
1422         plus = fuse_use_readdirplus(inode, ctx);
1423         req->out.argpages = 1;
1424         req->num_pages = 1;
1425         req->pages[0] = page;
1426         req->page_descs[0].length = PAGE_SIZE;
1427         if (plus) {
1428                 attr_version = fuse_get_attr_version(fc);
1429                 fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
1430                                FUSE_READDIRPLUS);
1431         } else {
1432                 fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
1433                                FUSE_READDIR);
1434         }
1435         fuse_request_send(fc, req);
1436         nbytes = req->out.args[0].size;
1437         err = req->out.h.error;
1438         fuse_put_request(fc, req);
1439         if (!err) {
1440                 if (plus) {
1441                         err = parse_dirplusfile(page_address(page), nbytes,
1442                                                 file, ctx,
1443                                                 attr_version);
1444                 } else {
1445                         err = parse_dirfile(page_address(page), nbytes, file,
1446                                             ctx);
1447                 }
1448         }
1449
1450         __free_page(page);
1451         fuse_invalidate_atime(inode);
1452         return err;
1453 }
1454
1455 static char *read_link(struct dentry *dentry)
1456 {
1457         struct inode *inode = dentry->d_inode;
1458         struct fuse_conn *fc = get_fuse_conn(inode);
1459         struct fuse_req *req = fuse_get_req_nopages(fc);
1460         char *link;
1461
1462         if (IS_ERR(req))
1463                 return ERR_CAST(req);
1464
1465         link = (char *) __get_free_page(GFP_KERNEL);
1466         if (!link) {
1467                 link = ERR_PTR(-ENOMEM);
1468                 goto out;
1469         }
1470         req->in.h.opcode = FUSE_READLINK;
1471         req->in.h.nodeid = get_node_id(inode);
1472         req->out.argvar = 1;
1473         req->out.numargs = 1;
1474         req->out.args[0].size = PAGE_SIZE - 1;
1475         req->out.args[0].value = link;
1476         fuse_request_send(fc, req);
1477         if (req->out.h.error) {
1478                 free_page((unsigned long) link);
1479                 link = ERR_PTR(req->out.h.error);
1480         } else
1481                 link[req->out.args[0].size] = '\0';
1482  out:
1483         fuse_put_request(fc, req);
1484         fuse_invalidate_atime(inode);
1485         return link;
1486 }
1487
1488 static void free_link(char *link)
1489 {
1490         if (!IS_ERR(link))
1491                 free_page((unsigned long) link);
1492 }
1493
1494 static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
1495 {
1496         nd_set_link(nd, read_link(dentry));
1497         return NULL;
1498 }
1499
1500 static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
1501 {
1502         free_link(nd_get_link(nd));
1503 }
1504
1505 static int fuse_dir_open(struct inode *inode, struct file *file)
1506 {
1507         return fuse_open_common(inode, file, true);
1508 }
1509
1510 static int fuse_dir_release(struct inode *inode, struct file *file)
1511 {
1512         fuse_release_common(file, FUSE_RELEASEDIR);
1513
1514         return 0;
1515 }
1516
1517 static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end,
1518                           int datasync)
1519 {
1520         return fuse_fsync_common(file, start, end, datasync, 1);
1521 }
1522
1523 static long fuse_dir_ioctl(struct file *file, unsigned int cmd,
1524                             unsigned long arg)
1525 {
1526         struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1527
1528         /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */
1529         if (fc->minor < 18)
1530                 return -ENOTTY;
1531
1532         return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR);
1533 }
1534
1535 static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd,
1536                                    unsigned long arg)
1537 {
1538         struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
1539
1540         if (fc->minor < 18)
1541                 return -ENOTTY;
1542
1543         return fuse_ioctl_common(file, cmd, arg,
1544                                  FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR);
1545 }
1546
1547 static bool update_mtime(unsigned ivalid, bool trust_local_mtime)
1548 {
1549         /* Always update if mtime is explicitly set  */
1550         if (ivalid & ATTR_MTIME_SET)
1551                 return true;
1552
1553         /* Or if kernel i_mtime is the official one */
1554         if (trust_local_mtime)
1555                 return true;
1556
1557         /* If it's an open(O_TRUNC) or an ftruncate(), don't update */
1558         if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
1559                 return false;
1560
1561         /* In all other cases update */
1562         return true;
1563 }
1564
1565 static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg,
1566                            bool trust_local_cmtime)
1567 {
1568         unsigned ivalid = iattr->ia_valid;
1569
1570         if (ivalid & ATTR_MODE)
1571                 arg->valid |= FATTR_MODE,   arg->mode = iattr->ia_mode;
1572         if (ivalid & ATTR_UID)
1573                 arg->valid |= FATTR_UID,    arg->uid = from_kuid(&init_user_ns, iattr->ia_uid);
1574         if (ivalid & ATTR_GID)
1575                 arg->valid |= FATTR_GID,    arg->gid = from_kgid(&init_user_ns, iattr->ia_gid);
1576         if (ivalid & ATTR_SIZE)
1577                 arg->valid |= FATTR_SIZE,   arg->size = iattr->ia_size;
1578         if (ivalid & ATTR_ATIME) {
1579                 arg->valid |= FATTR_ATIME;
1580                 arg->atime = iattr->ia_atime.tv_sec;
1581                 arg->atimensec = iattr->ia_atime.tv_nsec;
1582                 if (!(ivalid & ATTR_ATIME_SET))
1583                         arg->valid |= FATTR_ATIME_NOW;
1584         }
1585         if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_cmtime)) {
1586                 arg->valid |= FATTR_MTIME;
1587                 arg->mtime = iattr->ia_mtime.tv_sec;
1588                 arg->mtimensec = iattr->ia_mtime.tv_nsec;
1589                 if (!(ivalid & ATTR_MTIME_SET) && !trust_local_cmtime)
1590                         arg->valid |= FATTR_MTIME_NOW;
1591         }
1592         if ((ivalid & ATTR_CTIME) && trust_local_cmtime) {
1593                 arg->valid |= FATTR_CTIME;
1594                 arg->ctime = iattr->ia_ctime.tv_sec;
1595                 arg->ctimensec = iattr->ia_ctime.tv_nsec;
1596         }
1597 }
1598
1599 /*
1600  * Prevent concurrent writepages on inode
1601  *
1602  * This is done by adding a negative bias to the inode write counter
1603  * and waiting for all pending writes to finish.
1604  */
1605 void fuse_set_nowrite(struct inode *inode)
1606 {
1607         struct fuse_conn *fc = get_fuse_conn(inode);
1608         struct fuse_inode *fi = get_fuse_inode(inode);
1609
1610         BUG_ON(!mutex_is_locked(&inode->i_mutex));
1611
1612         spin_lock(&fc->lock);
1613         BUG_ON(fi->writectr < 0);
1614         fi->writectr += FUSE_NOWRITE;
1615         spin_unlock(&fc->lock);
1616         wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
1617 }
1618
1619 /*
1620  * Allow writepages on inode
1621  *
1622  * Remove the bias from the writecounter and send any queued
1623  * writepages.
1624  */
1625 static void __fuse_release_nowrite(struct inode *inode)
1626 {
1627         struct fuse_inode *fi = get_fuse_inode(inode);
1628
1629         BUG_ON(fi->writectr != FUSE_NOWRITE);
1630         fi->writectr = 0;
1631         fuse_flush_writepages(inode);
1632 }
1633
1634 void fuse_release_nowrite(struct inode *inode)
1635 {
1636         struct fuse_conn *fc = get_fuse_conn(inode);
1637
1638         spin_lock(&fc->lock);
1639         __fuse_release_nowrite(inode);
1640         spin_unlock(&fc->lock);
1641 }
1642
1643 static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_req *req,
1644                               struct inode *inode,
1645                               struct fuse_setattr_in *inarg_p,
1646                               struct fuse_attr_out *outarg_p)
1647 {
1648         req->in.h.opcode = FUSE_SETATTR;
1649         req->in.h.nodeid = get_node_id(inode);
1650         req->in.numargs = 1;
1651         req->in.args[0].size = sizeof(*inarg_p);
1652         req->in.args[0].value = inarg_p;
1653         req->out.numargs = 1;
1654         if (fc->minor < 9)
1655                 req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
1656         else
1657                 req->out.args[0].size = sizeof(*outarg_p);
1658         req->out.args[0].value = outarg_p;
1659 }
1660
1661 /*
1662  * Flush inode->i_mtime to the server
1663  */
1664 int fuse_flush_times(struct inode *inode, struct fuse_file *ff)
1665 {
1666         struct fuse_conn *fc = get_fuse_conn(inode);
1667         struct fuse_req *req;
1668         struct fuse_setattr_in inarg;
1669         struct fuse_attr_out outarg;
1670         int err;
1671
1672         req = fuse_get_req_nopages(fc);
1673         if (IS_ERR(req))
1674                 return PTR_ERR(req);
1675
1676         memset(&inarg, 0, sizeof(inarg));
1677         memset(&outarg, 0, sizeof(outarg));
1678
1679         inarg.valid = FATTR_MTIME;
1680         inarg.mtime = inode->i_mtime.tv_sec;
1681         inarg.mtimensec = inode->i_mtime.tv_nsec;
1682         if (fc->minor >= 23) {
1683                 inarg.valid |= FATTR_CTIME;
1684                 inarg.ctime = inode->i_ctime.tv_sec;
1685                 inarg.ctimensec = inode->i_ctime.tv_nsec;
1686         }
1687         if (ff) {
1688                 inarg.valid |= FATTR_FH;
1689                 inarg.fh = ff->fh;
1690         }
1691         fuse_setattr_fill(fc, req, inode, &inarg, &outarg);
1692         fuse_request_send(fc, req);
1693         err = req->out.h.error;
1694         fuse_put_request(fc, req);
1695
1696         return err;
1697 }
1698
1699 /*
1700  * Set attributes, and at the same time refresh them.
1701  *
1702  * Truncation is slightly complicated, because the 'truncate' request
1703  * may fail, in which case we don't want to touch the mapping.
1704  * vmtruncate() doesn't allow for this case, so do the rlimit checking
1705  * and the actual truncation by hand.
1706  */
1707 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
1708                     struct file *file)
1709 {
1710         struct fuse_conn *fc = get_fuse_conn(inode);
1711         struct fuse_inode *fi = get_fuse_inode(inode);
1712         struct fuse_req *req;
1713         struct fuse_setattr_in inarg;
1714         struct fuse_attr_out outarg;
1715         bool is_truncate = false;
1716         bool is_wb = fc->writeback_cache;
1717         loff_t oldsize;
1718         int err;
1719         bool trust_local_cmtime = is_wb && S_ISREG(inode->i_mode);
1720
1721         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
1722                 attr->ia_valid |= ATTR_FORCE;
1723
1724         err = inode_change_ok(inode, attr);
1725         if (err)
1726                 return err;
1727
1728         if (attr->ia_valid & ATTR_OPEN) {
1729                 if (fc->atomic_o_trunc)
1730                         return 0;
1731                 file = NULL;
1732         }
1733
1734         if (attr->ia_valid & ATTR_SIZE)
1735                 is_truncate = true;
1736
1737         req = fuse_get_req_nopages(fc);
1738         if (IS_ERR(req))
1739                 return PTR_ERR(req);
1740
1741         if (is_truncate) {
1742                 fuse_set_nowrite(inode);
1743                 set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1744                 if (trust_local_cmtime && attr->ia_size != inode->i_size)
1745                         attr->ia_valid |= ATTR_MTIME | ATTR_CTIME;
1746         }
1747
1748         memset(&inarg, 0, sizeof(inarg));
1749         memset(&outarg, 0, sizeof(outarg));
1750         iattr_to_fattr(attr, &inarg, trust_local_cmtime);
1751         if (file) {
1752                 struct fuse_file *ff = file->private_data;
1753                 inarg.valid |= FATTR_FH;
1754                 inarg.fh = ff->fh;
1755         }
1756         if (attr->ia_valid & ATTR_SIZE) {
1757                 /* For mandatory locking in truncate */
1758                 inarg.valid |= FATTR_LOCKOWNER;
1759                 inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
1760         }
1761         fuse_setattr_fill(fc, req, inode, &inarg, &outarg);
1762         fuse_request_send(fc, req);
1763         err = req->out.h.error;
1764         fuse_put_request(fc, req);
1765         if (err) {
1766                 if (err == -EINTR)
1767                         fuse_invalidate_attr(inode);
1768                 goto error;
1769         }
1770
1771         if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
1772                 make_bad_inode(inode);
1773                 err = -EIO;
1774                 goto error;
1775         }
1776
1777         spin_lock(&fc->lock);
1778         /* the kernel maintains i_mtime locally */
1779         if (trust_local_cmtime) {
1780                 if (attr->ia_valid & ATTR_MTIME)
1781                         inode->i_mtime = attr->ia_mtime;
1782                 if (attr->ia_valid & ATTR_CTIME)
1783                         inode->i_ctime = attr->ia_ctime;
1784                 /* FIXME: clear I_DIRTY_SYNC? */
1785         }
1786
1787         fuse_change_attributes_common(inode, &outarg.attr,
1788                                       attr_timeout(&outarg));
1789         oldsize = inode->i_size;
1790         /* see the comment in fuse_change_attributes() */
1791         if (!is_wb || is_truncate || !S_ISREG(inode->i_mode))
1792                 i_size_write(inode, outarg.attr.size);
1793
1794         if (is_truncate) {
1795                 /* NOTE: this may release/reacquire fc->lock */
1796                 __fuse_release_nowrite(inode);
1797         }
1798         spin_unlock(&fc->lock);
1799
1800         /*
1801          * Only call invalidate_inode_pages2() after removing
1802          * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
1803          */
1804         if ((is_truncate || !is_wb) &&
1805             S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
1806                 truncate_pagecache(inode, outarg.attr.size);
1807                 invalidate_inode_pages2(inode->i_mapping);
1808         }
1809
1810         clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1811         return 0;
1812
1813 error:
1814         if (is_truncate)
1815                 fuse_release_nowrite(inode);
1816
1817         clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
1818         return err;
1819 }
1820
1821 static int fuse_setattr(struct dentry *entry, struct iattr *attr)
1822 {
1823         struct inode *inode = entry->d_inode;
1824
1825         if (!fuse_allow_current_process(get_fuse_conn(inode)))
1826                 return -EACCES;
1827
1828         if (attr->ia_valid & ATTR_FILE)
1829                 return fuse_do_setattr(inode, attr, attr->ia_file);
1830         else
1831                 return fuse_do_setattr(inode, attr, NULL);
1832 }
1833
1834 static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
1835                         struct kstat *stat)
1836 {
1837         struct inode *inode = entry->d_inode;
1838         struct fuse_conn *fc = get_fuse_conn(inode);
1839
1840         if (!fuse_allow_current_process(fc))
1841                 return -EACCES;
1842
1843         return fuse_update_attributes(inode, stat, NULL, NULL);
1844 }
1845
1846 static int fuse_setxattr(struct dentry *entry, const char *name,
1847                          const void *value, size_t size, int flags)
1848 {
1849         struct inode *inode = entry->d_inode;
1850         struct fuse_conn *fc = get_fuse_conn(inode);
1851         struct fuse_req *req;
1852         struct fuse_setxattr_in inarg;
1853         int err;
1854
1855         if (fc->no_setxattr)
1856                 return -EOPNOTSUPP;
1857
1858         req = fuse_get_req_nopages(fc);
1859         if (IS_ERR(req))
1860                 return PTR_ERR(req);
1861
1862         memset(&inarg, 0, sizeof(inarg));
1863         inarg.size = size;
1864         inarg.flags = flags;
1865         req->in.h.opcode = FUSE_SETXATTR;
1866         req->in.h.nodeid = get_node_id(inode);
1867         req->in.numargs = 3;
1868         req->in.args[0].size = sizeof(inarg);
1869         req->in.args[0].value = &inarg;
1870         req->in.args[1].size = strlen(name) + 1;
1871         req->in.args[1].value = name;
1872         req->in.args[2].size = size;
1873         req->in.args[2].value = value;
1874         fuse_request_send(fc, req);
1875         err = req->out.h.error;
1876         fuse_put_request(fc, req);
1877         if (err == -ENOSYS) {
1878                 fc->no_setxattr = 1;
1879                 err = -EOPNOTSUPP;
1880         }
1881         if (!err) {
1882                 fuse_invalidate_attr(inode);
1883                 fuse_update_ctime(inode);
1884         }
1885         return err;
1886 }
1887
1888 static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
1889                              void *value, size_t size)
1890 {
1891         struct inode *inode = entry->d_inode;
1892         struct fuse_conn *fc = get_fuse_conn(inode);
1893         struct fuse_req *req;
1894         struct fuse_getxattr_in inarg;
1895         struct fuse_getxattr_out outarg;
1896         ssize_t ret;
1897
1898         if (fc->no_getxattr)
1899                 return -EOPNOTSUPP;
1900
1901         req = fuse_get_req_nopages(fc);
1902         if (IS_ERR(req))
1903                 return PTR_ERR(req);
1904
1905         memset(&inarg, 0, sizeof(inarg));
1906         inarg.size = size;
1907         req->in.h.opcode = FUSE_GETXATTR;
1908         req->in.h.nodeid = get_node_id(inode);
1909         req->in.numargs = 2;
1910         req->in.args[0].size = sizeof(inarg);
1911         req->in.args[0].value = &inarg;
1912         req->in.args[1].size = strlen(name) + 1;
1913         req->in.args[1].value = name;
1914         /* This is really two different operations rolled into one */
1915         req->out.numargs = 1;
1916         if (size) {
1917                 req->out.argvar = 1;
1918                 req->out.args[0].size = size;
1919                 req->out.args[0].value = value;
1920         } else {
1921                 req->out.args[0].size = sizeof(outarg);
1922                 req->out.args[0].value = &outarg;
1923         }
1924         fuse_request_send(fc, req);
1925         ret = req->out.h.error;
1926         if (!ret)
1927                 ret = size ? req->out.args[0].size : outarg.size;
1928         else {
1929                 if (ret == -ENOSYS) {
1930                         fc->no_getxattr = 1;
1931                         ret = -EOPNOTSUPP;
1932                 }
1933         }
1934         fuse_put_request(fc, req);
1935         return ret;
1936 }
1937
1938 static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
1939 {
1940         struct inode *inode = entry->d_inode;
1941         struct fuse_conn *fc = get_fuse_conn(inode);
1942         struct fuse_req *req;
1943         struct fuse_getxattr_in inarg;
1944         struct fuse_getxattr_out outarg;
1945         ssize_t ret;
1946
1947         if (!fuse_allow_current_process(fc))
1948                 return -EACCES;
1949
1950         if (fc->no_listxattr)
1951                 return -EOPNOTSUPP;
1952
1953         req = fuse_get_req_nopages(fc);
1954         if (IS_ERR(req))
1955                 return PTR_ERR(req);
1956
1957         memset(&inarg, 0, sizeof(inarg));
1958         inarg.size = size;
1959         req->in.h.opcode = FUSE_LISTXATTR;
1960         req->in.h.nodeid = get_node_id(inode);
1961         req->in.numargs = 1;
1962         req->in.args[0].size = sizeof(inarg);
1963         req->in.args[0].value = &inarg;
1964         /* This is really two different operations rolled into one */
1965         req->out.numargs = 1;
1966         if (size) {
1967                 req->out.argvar = 1;
1968                 req->out.args[0].size = size;
1969                 req->out.args[0].value = list;
1970         } else {
1971                 req->out.args[0].size = sizeof(outarg);
1972                 req->out.args[0].value = &outarg;
1973         }
1974         fuse_request_send(fc, req);
1975         ret = req->out.h.error;
1976         if (!ret)
1977                 ret = size ? req->out.args[0].size : outarg.size;
1978         else {
1979                 if (ret == -ENOSYS) {
1980                         fc->no_listxattr = 1;
1981                         ret = -EOPNOTSUPP;
1982                 }
1983         }
1984         fuse_put_request(fc, req);
1985         return ret;
1986 }
1987
1988 static int fuse_removexattr(struct dentry *entry, const char *name)
1989 {
1990         struct inode *inode = entry->d_inode;
1991         struct fuse_conn *fc = get_fuse_conn(inode);
1992         struct fuse_req *req;
1993         int err;
1994
1995         if (fc->no_removexattr)
1996                 return -EOPNOTSUPP;
1997
1998         req = fuse_get_req_nopages(fc);
1999         if (IS_ERR(req))
2000                 return PTR_ERR(req);
2001
2002         req->in.h.opcode = FUSE_REMOVEXATTR;
2003         req->in.h.nodeid = get_node_id(inode);
2004         req->in.numargs = 1;
2005         req->in.args[0].size = strlen(name) + 1;
2006         req->in.args[0].value = name;
2007         fuse_request_send(fc, req);
2008         err = req->out.h.error;
2009         fuse_put_request(fc, req);
2010         if (err == -ENOSYS) {
2011                 fc->no_removexattr = 1;
2012                 err = -EOPNOTSUPP;
2013         }
2014         if (!err) {
2015                 fuse_invalidate_attr(inode);
2016                 fuse_update_ctime(inode);
2017         }
2018         return err;
2019 }
2020
2021 static const struct inode_operations fuse_dir_inode_operations = {
2022         .lookup         = fuse_lookup,
2023         .mkdir          = fuse_mkdir,
2024         .symlink        = fuse_symlink,
2025         .unlink         = fuse_unlink,
2026         .rmdir          = fuse_rmdir,
2027         .rename         = fuse_rename,
2028         .rename2        = fuse_rename2,
2029         .link           = fuse_link,
2030         .setattr        = fuse_setattr,
2031         .create         = fuse_create,
2032         .atomic_open    = fuse_atomic_open,
2033         .mknod          = fuse_mknod,
2034         .permission     = fuse_permission,
2035         .getattr        = fuse_getattr,
2036         .setxattr       = fuse_setxattr,
2037         .getxattr       = fuse_getxattr,
2038         .listxattr      = fuse_listxattr,
2039         .removexattr    = fuse_removexattr,
2040 };
2041
2042 static const struct file_operations fuse_dir_operations = {
2043         .llseek         = generic_file_llseek,
2044         .read           = generic_read_dir,
2045         .iterate        = fuse_readdir,
2046         .open           = fuse_dir_open,
2047         .release        = fuse_dir_release,
2048         .fsync          = fuse_dir_fsync,
2049         .unlocked_ioctl = fuse_dir_ioctl,
2050         .compat_ioctl   = fuse_dir_compat_ioctl,
2051 };
2052
2053 static const struct inode_operations fuse_common_inode_operations = {
2054         .setattr        = fuse_setattr,
2055         .permission     = fuse_permission,
2056         .getattr        = fuse_getattr,
2057         .setxattr       = fuse_setxattr,
2058         .getxattr       = fuse_getxattr,
2059         .listxattr      = fuse_listxattr,
2060         .removexattr    = fuse_removexattr,
2061 };
2062
2063 static const struct inode_operations fuse_symlink_inode_operations = {
2064         .setattr        = fuse_setattr,
2065         .follow_link    = fuse_follow_link,
2066         .put_link       = fuse_put_link,
2067         .readlink       = generic_readlink,
2068         .getattr        = fuse_getattr,
2069         .setxattr       = fuse_setxattr,
2070         .getxattr       = fuse_getxattr,
2071         .listxattr      = fuse_listxattr,
2072         .removexattr    = fuse_removexattr,
2073 };
2074
2075 void fuse_init_common(struct inode *inode)
2076 {
2077         inode->i_op = &fuse_common_inode_operations;
2078 }
2079
2080 void fuse_init_dir(struct inode *inode)
2081 {
2082         inode->i_op = &fuse_dir_inode_operations;
2083         inode->i_fop = &fuse_dir_operations;
2084 }
2085
2086 void fuse_init_symlink(struct inode *inode)
2087 {
2088         inode->i_op = &fuse_symlink_inode_operations;
2089 }