fs/fuse/file.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/kernel.h>
  14 #include <linux/sched.h>
  15
  16 static const struct file_operations fuse_direct_io_file_operations;
  17
  18 static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
  19                           struct fuse_open_out *outargp)
  20 {
  21         struct fuse_conn *fc = get_fuse_conn(inode);
  22         struct fuse_open_in inarg;
  23         struct fuse_req *req;
  24         int err;
  25
  26         req = fuse_get_req(fc);
  27         if (IS_ERR(req))
  28                 return PTR_ERR(req);
  29
  30         memset(&inarg, 0, sizeof(inarg));
  31         inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
  32         if (!fc->atomic_o_trunc)
  33                 inarg.flags &= ~O_TRUNC;
  34         req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
  35         req->in.h.nodeid = get_node_id(inode);
  36         req->in.numargs = 1;
  37         req->in.args[0].size = sizeof(inarg);
  38         req->in.args[0].value = &inarg;
  39         req->out.numargs = 1;
  40         req->out.args[0].size = sizeof(*outargp);
  41         req->out.args[0].value = outargp;
  42         request_send(fc, req);
  43         err = req->out.h.error;
  44         fuse_put_request(fc, req);
  45
  46         return err;
  47 }
  48
  49 struct fuse_file *fuse_file_alloc(void)
  50 {
  51         struct fuse_file *ff;
  52         ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
  53         if (ff) {
  54                 ff->reserved_req = fuse_request_alloc();
  55                 if (!ff->reserved_req) {
  56                         kfree(ff);
  57                         ff = NULL;
  58                 }
  59                 atomic_set(&ff->count, 0);
  60         }
  61         return ff;
  62 }
  63
  64 void fuse_file_free(struct fuse_file *ff)
  65 {
  66         fuse_request_free(ff->reserved_req);
  67         kfree(ff);
  68 }
  69
  70 static struct fuse_file *fuse_file_get(struct fuse_file *ff)
  71 {
  72         atomic_inc(&ff->count);
  73         return ff;
  74 }
  75
  76 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
  77 {
  78         dput(req->dentry);
  79         mntput(req->vfsmount);
  80         fuse_put_request(fc, req);
  81 }
  82
  83 static void fuse_file_put(struct fuse_file *ff)
  84 {
  85         if (atomic_dec_and_test(&ff->count)) {
  86                 struct fuse_req *req = ff->reserved_req;
  87                 struct fuse_conn *fc = get_fuse_conn(req->dentry->d_inode);
  88                 req->end = fuse_release_end;
  89                 request_send_background(fc, req);
  90                 kfree(ff);
  91         }
  92 }
  93
  94 void fuse_finish_open(struct inode *inode, struct file *file,
  95                       struct fuse_file *ff, struct fuse_open_out *outarg)
  96 {
  97         if (outarg->open_flags & FOPEN_DIRECT_IO)
  98                 file->f_op = &fuse_direct_io_file_operations;
  99         if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
 100                 invalidate_inode_pages2(inode->i_mapping);
 101         ff->fh = outarg->fh;
 102         file->private_data = fuse_file_get(ff);
 103 }
 104
 105 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
 106 {
 107         struct fuse_open_out outarg;
 108         struct fuse_file *ff;
 109         int err;
 110
 111         /* VFS checks this, but only _after_ ->open() */
 112         if (file->f_flags & O_DIRECT)
 113                 return -EINVAL;
 114
 115         err = generic_file_open(inode, file);
 116         if (err)
 117                 return err;
 118
 119         ff = fuse_file_alloc();
 120         if (!ff)
 121                 return -ENOMEM;
 122
 123         err = fuse_send_open(inode, file, isdir, &outarg);
 124         if (err)
 125                 fuse_file_free(ff);
 126         else {
 127                 if (isdir)
 128                         outarg.open_flags &= ~FOPEN_DIRECT_IO;
 129                 fuse_finish_open(inode, file, ff, &outarg);
 130         }
 131
 132         return err;
 133 }
 134
 135 void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
 136 {
 137         struct fuse_req *req = ff->reserved_req;
 138         struct fuse_release_in *inarg = &req->misc.release_in;
 139
 140         inarg->fh = ff->fh;
 141         inarg->flags = flags;
 142         req->in.h.opcode = opcode;
 143         req->in.h.nodeid = nodeid;
 144         req->in.numargs = 1;
 145         req->in.args[0].size = sizeof(struct fuse_release_in);
 146         req->in.args[0].value = inarg;
 147 }
 148
 149 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
 150 {
 151         struct fuse_file *ff = file->private_data;
 152         if (ff) {
 153                 fuse_release_fill(ff, get_node_id(inode), file->f_flags,
 154                                   isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
 155
 156                 /* Hold vfsmount and dentry until release is finished */
 157                 ff->reserved_req->vfsmount = mntget(file->f_path.mnt);
 158                 ff->reserved_req->dentry = dget(file->f_path.dentry);
 159                 /*
 160                  * Normally this will send the RELEASE request,
 161                  * however if some asynchronous READ or WRITE requests
 162                  * are outstanding, the sending will be delayed
 163                  */
 164                 fuse_file_put(ff);
 165         }
 166
 167         /* Return value is ignored by VFS */
 168         return 0;
 169 }
 170
 171 static int fuse_open(struct inode *inode, struct file *file)
 172 {
 173         return fuse_open_common(inode, file, 0);
 174 }
 175
 176 static int fuse_release(struct inode *inode, struct file *file)
 177 {
 178         return fuse_release_common(inode, file, 0);
 179 }
 180
 181 /*
 182  * Scramble the ID space with XTEA, so that the value of the files_struct
 183  * pointer is not exposed to userspace.
 184  */
 185 static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
 186 {
 187         u32 *k = fc->scramble_key;
 188         u64 v = (unsigned long) id;
 189         u32 v0 = v;
 190         u32 v1 = v >> 32;
 191         u32 sum = 0;
 192         int i;
 193
 194         for (i = 0; i < 32; i++) {
 195                 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
 196                 sum += 0x9E3779B9;
 197                 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
 198         }
 199
 200         return (u64) v0 + ((u64) v1 << 32);
 201 }
 202
 203 static int fuse_flush(struct file *file, fl_owner_t id)
 204 {
 205         struct inode *inode = file->f_path.dentry->d_inode;
 206         struct fuse_conn *fc = get_fuse_conn(inode);
 207         struct fuse_file *ff = file->private_data;
 208         struct fuse_req *req;
 209         struct fuse_flush_in inarg;
 210         int err;
 211
 212         if (is_bad_inode(inode))
 213                 return -EIO;
 214
 215         if (fc->no_flush)
 216                 return 0;
 217
 218         req = fuse_get_req_nofail(fc, file);
 219         memset(&inarg, 0, sizeof(inarg));
 220         inarg.fh = ff->fh;
 221         inarg.lock_owner = fuse_lock_owner_id(fc, id);
 222         req->in.h.opcode = FUSE_FLUSH;
 223         req->in.h.nodeid = get_node_id(inode);
 224         req->in.numargs = 1;
 225         req->in.args[0].size = sizeof(inarg);
 226         req->in.args[0].value = &inarg;
 227         req->force = 1;
 228         request_send(fc, req);
 229         err = req->out.h.error;
 230         fuse_put_request(fc, req);
 231         if (err == -ENOSYS) {
 232                 fc->no_flush = 1;
 233                 err = 0;
 234         }
 235         return err;
 236 }
 237
 238 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
 239                       int isdir)
 240 {
 241         struct inode *inode = de->d_inode;
 242         struct fuse_conn *fc = get_fuse_conn(inode);
 243         struct fuse_file *ff = file->private_data;
 244         struct fuse_req *req;
 245         struct fuse_fsync_in inarg;
 246         int err;
 247
 248         if (is_bad_inode(inode))
 249                 return -EIO;
 250
 251         if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
 252                 return 0;
 253
 254         req = fuse_get_req(fc);
 255         if (IS_ERR(req))
 256                 return PTR_ERR(req);
 257
 258         memset(&inarg, 0, sizeof(inarg));
 259         inarg.fh = ff->fh;
 260         inarg.fsync_flags = datasync ? 1 : 0;
 261         req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
 262         req->in.h.nodeid = get_node_id(inode);
 263         req->in.numargs = 1;
 264         req->in.args[0].size = sizeof(inarg);
 265         req->in.args[0].value = &inarg;
 266         request_send(fc, req);
 267         err = req->out.h.error;
 268         fuse_put_request(fc, req);
 269         if (err == -ENOSYS) {
 270                 if (isdir)
 271                         fc->no_fsyncdir = 1;
 272                 else
 273                         fc->no_fsync = 1;
 274                 err = 0;
 275         }
 276         return err;
 277 }
 278
 279 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
 280 {
 281         return fuse_fsync_common(file, de, datasync, 0);
 282 }
 283
 284 void fuse_read_fill(struct fuse_req *req, struct fuse_file *ff,
 285                     struct inode *inode, loff_t pos, size_t count, int opcode)
 286 {
 287         struct fuse_read_in *inarg = &req->misc.read_in;
 288
 289         inarg->fh = ff->fh;
 290         inarg->offset = pos;
 291         inarg->size = count;
 292         req->in.h.opcode = opcode;
 293         req->in.h.nodeid = get_node_id(inode);
 294         req->in.numargs = 1;
 295         req->in.args[0].size = sizeof(struct fuse_read_in);
 296         req->in.args[0].value = inarg;
 297         req->out.argpages = 1;
 298         req->out.argvar = 1;
 299         req->out.numargs = 1;
 300         req->out.args[0].size = count;
 301 }
 302
 303 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
 304                              struct inode *inode, loff_t pos, size_t count)
 305 {
 306         struct fuse_conn *fc = get_fuse_conn(inode);
 307         struct fuse_file *ff = file->private_data;
 308         fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
 309         request_send(fc, req);
 310         return req->out.args[0].size;
 311 }
 312
 313 static int fuse_readpage(struct file *file, struct page *page)
 314 {
 315         struct inode *inode = page->mapping->host;
 316         struct fuse_conn *fc = get_fuse_conn(inode);
 317         struct fuse_req *req;
 318         int err;
 319
 320         err = -EIO;
 321         if (is_bad_inode(inode))
 322                 goto out;
 323
 324         req = fuse_get_req(fc);
 325         err = PTR_ERR(req);
 326         if (IS_ERR(req))
 327                 goto out;
 328
 329         req->out.page_zeroing = 1;
 330         req->num_pages = 1;
 331         req->pages[0] = page;
 332         fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
 333         err = req->out.h.error;
 334         fuse_put_request(fc, req);
 335         if (!err)
 336                 SetPageUptodate(page);
 337         fuse_invalidate_attr(inode); /* atime changed */
 338  out:
 339         unlock_page(page);
 340         return err;
 341 }
 342
 343 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
 344 {
 345         int i;
 346
 347         fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
 348
 349         for (i = 0; i < req->num_pages; i++) {
 350                 struct page *page = req->pages[i];
 351                 if (!req->out.h.error)
 352                         SetPageUptodate(page);
 353                 else
 354                         SetPageError(page);
 355                 unlock_page(page);
 356         }
 357         if (req->ff)
 358                 fuse_file_put(req->ff);
 359         fuse_put_request(fc, req);
 360 }
 361
 362 static void fuse_send_readpages(struct fuse_req *req, struct fuse_file *ff,
 363                                 struct inode *inode)
 364 {
 365         struct fuse_conn *fc = get_fuse_conn(inode);
 366         loff_t pos = page_offset(req->pages[0]);
 367         size_t count = req->num_pages << PAGE_CACHE_SHIFT;
 368         req->out.page_zeroing = 1;
 369         fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
 370         if (fc->async_read) {
 371                 req->ff = fuse_file_get(ff);
 372                 req->end = fuse_readpages_end;
 373                 request_send_background(fc, req);
 374         } else {
 375                 request_send(fc, req);
 376                 fuse_readpages_end(fc, req);
 377         }
 378 }
 379
 380 struct fuse_fill_data {
 381         struct fuse_req *req;
 382         struct fuse_file *ff;
 383         struct inode *inode;
 384 };
 385
 386 static int fuse_readpages_fill(void *_data, struct page *page)
 387 {
 388         struct fuse_fill_data *data = _data;
 389         struct fuse_req *req = data->req;
 390         struct inode *inode = data->inode;
 391         struct fuse_conn *fc = get_fuse_conn(inode);
 392
 393         if (req->num_pages &&
 394             (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
 395              (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
 396              req->pages[req->num_pages - 1]->index + 1 != page->index)) {
 397                 fuse_send_readpages(req, data->ff, inode);
 398                 data->req = req = fuse_get_req(fc);
 399                 if (IS_ERR(req)) {
 400                         unlock_page(page);
 401                         return PTR_ERR(req);
 402                 }
 403         }
 404         req->pages[req->num_pages] = page;
 405         req->num_pages ++;
 406         return 0;
 407 }
 408
 409 static int fuse_readpages(struct file *file, struct address_space *mapping,
 410                           struct list_head *pages, unsigned nr_pages)
 411 {
 412         struct inode *inode = mapping->host;
 413         struct fuse_conn *fc = get_fuse_conn(inode);
 414         struct fuse_fill_data data;
 415         int err;
 416
 417         err = -EIO;
 418         if (is_bad_inode(inode))
 419                 goto out;
 420
 421         data.ff = file->private_data;
 422         data.inode = inode;
 423         data.req = fuse_get_req(fc);
 424         err = PTR_ERR(data.req);
 425         if (IS_ERR(data.req))
 426                 goto out;
 427
 428         err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
 429         if (!err) {
 430                 if (data.req->num_pages)
 431                         fuse_send_readpages(data.req, data.ff, inode);
 432                 else
 433                         fuse_put_request(fc, data.req);
 434         }
 435 out:
 436         return err;
 437 }
 438
 439 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
 440                               struct inode *inode, loff_t pos, size_t count)
 441 {
 442         struct fuse_conn *fc = get_fuse_conn(inode);
 443         struct fuse_file *ff = file->private_data;
 444         struct fuse_write_in inarg;
 445         struct fuse_write_out outarg;
 446
 447         memset(&inarg, 0, sizeof(struct fuse_write_in));
 448         inarg.fh = ff->fh;
 449         inarg.offset = pos;
 450         inarg.size = count;
 451         req->in.h.opcode = FUSE_WRITE;
 452         req->in.h.nodeid = get_node_id(inode);
 453         req->in.argpages = 1;
 454         req->in.numargs = 2;
 455         req->in.args[0].size = sizeof(struct fuse_write_in);
 456         req->in.args[0].value = &inarg;
 457         req->in.args[1].size = count;
 458         req->out.numargs = 1;
 459         req->out.args[0].size = sizeof(struct fuse_write_out);
 460         req->out.args[0].value = &outarg;
 461         request_send(fc, req);
 462         return outarg.size;
 463 }
 464
 465 static int fuse_write_begin(struct file *file, struct address_space *mapping,
 466                         loff_t pos, unsigned len, unsigned flags,
 467                         struct page **pagep, void **fsdata)
 468 {
 469         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 470
 471         *pagep = __grab_cache_page(mapping, index);
 472         if (!*pagep)
 473                 return -ENOMEM;
 474         return 0;
 475 }
 476
 477 static int fuse_buffered_write(struct file *file, struct inode *inode,
 478                                loff_t pos, unsigned count, struct page *page)
 479 {
 480         int err;
 481         size_t nres;
 482         struct fuse_conn *fc = get_fuse_conn(inode);
 483         struct fuse_inode *fi = get_fuse_inode(inode);
 484         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
 485         struct fuse_req *req;
 486
 487         if (is_bad_inode(inode))
 488                 return -EIO;
 489
 490         req = fuse_get_req(fc);
 491         if (IS_ERR(req))
 492                 return PTR_ERR(req);
 493
 494         req->num_pages = 1;
 495         req->pages[0] = page;
 496         req->page_offset = offset;
 497         nres = fuse_send_write(req, file, inode, pos, count);
 498         err = req->out.h.error;
 499         fuse_put_request(fc, req);
 500         if (!err && !nres)
 501                 err = -EIO;
 502         if (!err) {
 503                 pos += nres;
 504                 spin_lock(&fc->lock);
 505                 fi->attr_version = ++fc->attr_version;
 506                 if (pos > inode->i_size)
 507                         i_size_write(inode, pos);
 508                 spin_unlock(&fc->lock);
 509
 510                 if (count == PAGE_CACHE_SIZE)
 511                         SetPageUptodate(page);
 512         }
 513         fuse_invalidate_attr(inode);
 514         return err ? err : nres;
 515 }
 516
 517 static int fuse_write_end(struct file *file, struct address_space *mapping,
 518                         loff_t pos, unsigned len, unsigned copied,
 519                         struct page *page, void *fsdata)
 520 {
 521         struct inode *inode = mapping->host;
 522         int res = 0;
 523
 524         if (copied)
 525                 res = fuse_buffered_write(file, inode, pos, copied, page);
 526
 527         unlock_page(page);
 528         page_cache_release(page);
 529         return res;
 530 }
 531
 532 static void fuse_release_user_pages(struct fuse_req *req, int write)
 533 {
 534         unsigned i;
 535
 536         for (i = 0; i < req->num_pages; i++) {
 537                 struct page *page = req->pages[i];
 538                 if (write)
 539                         set_page_dirty_lock(page);
 540                 put_page(page);
 541         }
 542 }
 543
 544 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
 545                                unsigned nbytes, int write)
 546 {
 547         unsigned long user_addr = (unsigned long) buf;
 548         unsigned offset = user_addr & ~PAGE_MASK;
 549         int npages;
 550
 551         /* This doesn't work with nfsd */
 552         if (!current->mm)
 553                 return -EPERM;
 554
 555         nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
 556         npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
 557         npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
 558         down_read(&current->mm->mmap_sem);
 559         npages = get_user_pages(current, current->mm, user_addr, npages, write,
 560                                 0, req->pages, NULL);
 561         up_read(&current->mm->mmap_sem);
 562         if (npages < 0)
 563                 return npages;
 564
 565         req->num_pages = npages;
 566         req->page_offset = offset;
 567         return 0;
 568 }
 569
 570 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
 571                               size_t count, loff_t *ppos, int write)
 572 {
 573         struct inode *inode = file->f_path.dentry->d_inode;
 574         struct fuse_conn *fc = get_fuse_conn(inode);
 575         size_t nmax = write ? fc->max_write : fc->max_read;
 576         loff_t pos = *ppos;
 577         ssize_t res = 0;
 578         struct fuse_req *req;
 579
 580         if (is_bad_inode(inode))
 581                 return -EIO;
 582
 583         req = fuse_get_req(fc);
 584         if (IS_ERR(req))
 585                 return PTR_ERR(req);
 586
 587         while (count) {
 588                 size_t nres;
 589                 size_t nbytes = min(count, nmax);
 590                 int err = fuse_get_user_pages(req, buf, nbytes, !write);
 591                 if (err) {
 592                         res = err;
 593                         break;
 594                 }
 595                 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
 596                 nbytes = min(count, nbytes);
 597                 if (write)
 598                         nres = fuse_send_write(req, file, inode, pos, nbytes);
 599                 else
 600                         nres = fuse_send_read(req, file, inode, pos, nbytes);
 601                 fuse_release_user_pages(req, !write);
 602                 if (req->out.h.error) {
 603                         if (!res)
 604                                 res = req->out.h.error;
 605                         break;
 606                 } else if (nres > nbytes) {
 607                         res = -EIO;
 608                         break;
 609                 }
 610                 count -= nres;
 611                 res += nres;
 612                 pos += nres;
 613                 buf += nres;
 614                 if (nres != nbytes)
 615                         break;
 616                 if (count) {
 617                         fuse_put_request(fc, req);
 618                         req = fuse_get_req(fc);
 619                         if (IS_ERR(req))
 620                                 break;
 621                 }
 622         }
 623         fuse_put_request(fc, req);
 624         if (res > 0) {
 625                 if (write) {
 626                         spin_lock(&fc->lock);
 627                         if (pos > inode->i_size)
 628                                 i_size_write(inode, pos);
 629                         spin_unlock(&fc->lock);
 630                 }
 631                 *ppos = pos;
 632         }
 633         fuse_invalidate_attr(inode);
 634
 635         return res;
 636 }
 637
 638 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
 639                                      size_t count, loff_t *ppos)
 640 {
 641         return fuse_direct_io(file, buf, count, ppos, 0);
 642 }
 643
 644 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
 645                                  size_t count, loff_t *ppos)
 646 {
 647         struct inode *inode = file->f_path.dentry->d_inode;
 648         ssize_t res;
 649         /* Don't allow parallel writes to the same file */
 650         mutex_lock(&inode->i_mutex);
 651         res = generic_write_checks(file, ppos, &count, 0);
 652         if (!res)
 653                 res = fuse_direct_io(file, buf, count, ppos, 1);
 654         mutex_unlock(&inode->i_mutex);
 655         return res;
 656 }
 657
 658 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
 659 {
 660         if ((vma->vm_flags & VM_SHARED)) {
 661                 if ((vma->vm_flags & VM_WRITE))
 662                         return -ENODEV;
 663                 else
 664                         vma->vm_flags &= ~VM_MAYWRITE;
 665         }
 666         return generic_file_mmap(file, vma);
 667 }
 668
 669 static int fuse_set_page_dirty(struct page *page)
 670 {
 671         printk("fuse_set_page_dirty: should not happen\n");
 672         dump_stack();
 673         return 0;
 674 }
 675
 676 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
 677                                   struct file_lock *fl)
 678 {
 679         switch (ffl->type) {
 680         case F_UNLCK:
 681                 break;
 682
 683         case F_RDLCK:
 684         case F_WRLCK:
 685                 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
 686                     ffl->end < ffl->start)
 687                         return -EIO;
 688
 689                 fl->fl_start = ffl->start;
 690                 fl->fl_end = ffl->end;
 691                 fl->fl_pid = ffl->pid;
 692                 break;
 693
 694         default:
 695                 return -EIO;
 696         }
 697         fl->fl_type = ffl->type;
 698         return 0;
 699 }
 700
 701 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
 702                          const struct file_lock *fl, int opcode, pid_t pid)
 703 {
 704         struct inode *inode = file->f_path.dentry->d_inode;
 705         struct fuse_conn *fc = get_fuse_conn(inode);
 706         struct fuse_file *ff = file->private_data;
 707         struct fuse_lk_in *arg = &req->misc.lk_in;
 708
 709         arg->fh = ff->fh;
 710         arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
 711         arg->lk.start = fl->fl_start;
 712         arg->lk.end = fl->fl_end;
 713         arg->lk.type = fl->fl_type;
 714         arg->lk.pid = pid;
 715         req->in.h.opcode = opcode;
 716         req->in.h.nodeid = get_node_id(inode);
 717         req->in.numargs = 1;
 718         req->in.args[0].size = sizeof(*arg);
 719         req->in.args[0].value = arg;
 720 }
 721
 722 static int fuse_getlk(struct file *file, struct file_lock *fl)
 723 {
 724         struct inode *inode = file->f_path.dentry->d_inode;
 725         struct fuse_conn *fc = get_fuse_conn(inode);
 726         struct fuse_req *req;
 727         struct fuse_lk_out outarg;
 728         int err;
 729
 730         req = fuse_get_req(fc);
 731         if (IS_ERR(req))
 732                 return PTR_ERR(req);
 733
 734         fuse_lk_fill(req, file, fl, FUSE_GETLK, 0);
 735         req->out.numargs = 1;
 736         req->out.args[0].size = sizeof(outarg);
 737         req->out.args[0].value = &outarg;
 738         request_send(fc, req);
 739         err = req->out.h.error;
 740         fuse_put_request(fc, req);
 741         if (!err)
 742                 err = convert_fuse_file_lock(&outarg.lk, fl);
 743
 744         return err;
 745 }
 746
 747 static int fuse_setlk(struct file *file, struct file_lock *fl)
 748 {
 749         struct inode *inode = file->f_path.dentry->d_inode;
 750         struct fuse_conn *fc = get_fuse_conn(inode);
 751         struct fuse_req *req;
 752         int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
 753         pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
 754         int err;
 755
 756         /* Unlock on close is handled by the flush method */
 757         if (fl->fl_flags & FL_CLOSE)
 758                 return 0;
 759
 760         req = fuse_get_req(fc);
 761         if (IS_ERR(req))
 762                 return PTR_ERR(req);
 763
 764         fuse_lk_fill(req, file, fl, opcode, pid);
 765         request_send(fc, req);
 766         err = req->out.h.error;
 767         /* locking is restartable */
 768         if (err == -EINTR)
 769                 err = -ERESTARTSYS;
 770         fuse_put_request(fc, req);
 771         return err;
 772 }
 773
 774 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
 775 {
 776         struct inode *inode = file->f_path.dentry->d_inode;
 777         struct fuse_conn *fc = get_fuse_conn(inode);
 778         int err;
 779
 780         if (cmd == F_GETLK) {
 781                 if (fc->no_lock) {
 782                         posix_test_lock(file, fl);
 783                         err = 0;
 784                 } else
 785                         err = fuse_getlk(file, fl);
 786         } else {
 787                 if (fc->no_lock)
 788                         err = posix_lock_file_wait(file, fl);
 789                 else
 790                         err = fuse_setlk(file, fl);
 791         }
 792         return err;
 793 }
 794
 795 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
 796 {
 797         struct inode *inode = mapping->host;
 798         struct fuse_conn *fc = get_fuse_conn(inode);
 799         struct fuse_req *req;
 800         struct fuse_bmap_in inarg;
 801         struct fuse_bmap_out outarg;
 802         int err;
 803
 804         if (!inode->i_sb->s_bdev || fc->no_bmap)
 805                 return 0;
 806
 807         req = fuse_get_req(fc);
 808         if (IS_ERR(req))
 809                 return 0;
 810
 811         memset(&inarg, 0, sizeof(inarg));
 812         inarg.block = block;
 813         inarg.blocksize = inode->i_sb->s_blocksize;
 814         req->in.h.opcode = FUSE_BMAP;
 815         req->in.h.nodeid = get_node_id(inode);
 816         req->in.numargs = 1;
 817         req->in.args[0].size = sizeof(inarg);
 818         req->in.args[0].value = &inarg;
 819         req->out.numargs = 1;
 820         req->out.args[0].size = sizeof(outarg);
 821         req->out.args[0].value = &outarg;
 822         request_send(fc, req);
 823         err = req->out.h.error;
 824         fuse_put_request(fc, req);
 825         if (err == -ENOSYS)
 826                 fc->no_bmap = 1;
 827
 828         return err ? 0 : outarg.block;
 829 }
 830
 831 static const struct file_operations fuse_file_operations = {
 832         .llseek         = generic_file_llseek,
 833         .read           = do_sync_read,
 834         .aio_read       = generic_file_aio_read,
 835         .write          = do_sync_write,
 836         .aio_write      = generic_file_aio_write,
 837         .mmap           = fuse_file_mmap,
 838         .open           = fuse_open,
 839         .flush          = fuse_flush,
 840         .release        = fuse_release,
 841         .fsync          = fuse_fsync,
 842         .lock           = fuse_file_lock,
 843         .splice_read    = generic_file_splice_read,
 844 };
 845
 846 static const struct file_operations fuse_direct_io_file_operations = {
 847         .llseek         = generic_file_llseek,
 848         .read           = fuse_direct_read,
 849         .write          = fuse_direct_write,
 850         .open           = fuse_open,
 851         .flush          = fuse_flush,
 852         .release        = fuse_release,
 853         .fsync          = fuse_fsync,
 854         .lock           = fuse_file_lock,
 855         /* no mmap and splice_read */
 856 };
 857
 858 static const struct address_space_operations fuse_file_aops  = {
 859         .readpage       = fuse_readpage,
 860         .write_begin    = fuse_write_begin,
 861         .write_end      = fuse_write_end,
 862         .readpages      = fuse_readpages,
 863         .set_page_dirty = fuse_set_page_dirty,
 864         .bmap           = fuse_bmap,
 865 };
 866
 867 void fuse_init_file_inode(struct inode *inode)
 868 {
 869         inode->i_fop = &fuse_file_operations;
 870         inode->i_data.a_ops = &fuse_file_aops;
 871 }