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