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                 INIT_LIST_HEAD(&ff->write_entry);
  60                 atomic_set(&ff->count, 0);
  61         }
  62         return ff;
  63 }
  64
  65 void fuse_file_free(struct fuse_file *ff)
  66 {
  67         fuse_request_free(ff->reserved_req);
  68         kfree(ff);
  69 }
  70
  71 static struct fuse_file *fuse_file_get(struct fuse_file *ff)
  72 {
  73         atomic_inc(&ff->count);
  74         return ff;
  75 }
  76
  77 static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
  78 {
  79         dput(req->dentry);
  80         mntput(req->vfsmount);
  81         fuse_put_request(fc, req);
  82 }
  83
  84 static void fuse_file_put(struct fuse_file *ff)
  85 {
  86         if (atomic_dec_and_test(&ff->count)) {
  87                 struct fuse_req *req = ff->reserved_req;
  88                 struct fuse_conn *fc = get_fuse_conn(req->dentry->d_inode);
  89                 req->end = fuse_release_end;
  90                 request_send_background(fc, req);
  91                 kfree(ff);
  92         }
  93 }
  94
  95 void fuse_finish_open(struct inode *inode, struct file *file,
  96                       struct fuse_file *ff, struct fuse_open_out *outarg)
  97 {
  98         if (outarg->open_flags & FOPEN_DIRECT_IO)
  99                 file->f_op = &fuse_direct_io_file_operations;
 100         if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
 101                 invalidate_inode_pages2(inode->i_mapping);
 102         ff->fh = outarg->fh;
 103         file->private_data = fuse_file_get(ff);
 104 }
 105
 106 int fuse_open_common(struct inode *inode, struct file *file, int isdir)
 107 {
 108         struct fuse_open_out outarg;
 109         struct fuse_file *ff;
 110         int err;
 111
 112         /* VFS checks this, but only _after_ ->open() */
 113         if (file->f_flags & O_DIRECT)
 114                 return -EINVAL;
 115
 116         err = generic_file_open(inode, file);
 117         if (err)
 118                 return err;
 119
 120         ff = fuse_file_alloc();
 121         if (!ff)
 122                 return -ENOMEM;
 123
 124         err = fuse_send_open(inode, file, isdir, &outarg);
 125         if (err)
 126                 fuse_file_free(ff);
 127         else {
 128                 if (isdir)
 129                         outarg.open_flags &= ~FOPEN_DIRECT_IO;
 130                 fuse_finish_open(inode, file, ff, &outarg);
 131         }
 132
 133         return err;
 134 }
 135
 136 void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode)
 137 {
 138         struct fuse_req *req = ff->reserved_req;
 139         struct fuse_release_in *inarg = &req->misc.release_in;
 140
 141         inarg->fh = ff->fh;
 142         inarg->flags = flags;
 143         req->in.h.opcode = opcode;
 144         req->in.h.nodeid = nodeid;
 145         req->in.numargs = 1;
 146         req->in.args[0].size = sizeof(struct fuse_release_in);
 147         req->in.args[0].value = inarg;
 148 }
 149
 150 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
 151 {
 152         struct fuse_file *ff = file->private_data;
 153         if (ff) {
 154                 struct fuse_conn *fc = get_fuse_conn(inode);
 155
 156                 fuse_release_fill(ff, get_node_id(inode), file->f_flags,
 157                                   isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
 158
 159                 /* Hold vfsmount and dentry until release is finished */
 160                 ff->reserved_req->vfsmount = mntget(file->f_path.mnt);
 161                 ff->reserved_req->dentry = dget(file->f_path.dentry);
 162
 163                 spin_lock(&fc->lock);
 164                 list_del(&ff->write_entry);
 165                 spin_unlock(&fc->lock);
 166                 /*
 167                  * Normally this will send the RELEASE request,
 168                  * however if some asynchronous READ or WRITE requests
 169                  * are outstanding, the sending will be delayed
 170                  */
 171                 fuse_file_put(ff);
 172         }
 173
 174         /* Return value is ignored by VFS */
 175         return 0;
 176 }
 177
 178 static int fuse_open(struct inode *inode, struct file *file)
 179 {
 180         return fuse_open_common(inode, file, 0);
 181 }
 182
 183 static int fuse_release(struct inode *inode, struct file *file)
 184 {
 185         return fuse_release_common(inode, file, 0);
 186 }
 187
 188 /*
 189  * Scramble the ID space with XTEA, so that the value of the files_struct
 190  * pointer is not exposed to userspace.
 191  */
 192 static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
 193 {
 194         u32 *k = fc->scramble_key;
 195         u64 v = (unsigned long) id;
 196         u32 v0 = v;
 197         u32 v1 = v >> 32;
 198         u32 sum = 0;
 199         int i;
 200
 201         for (i = 0; i < 32; i++) {
 202                 v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
 203                 sum += 0x9E3779B9;
 204                 v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
 205         }
 206
 207         return (u64) v0 + ((u64) v1 << 32);
 208 }
 209
 210 static int fuse_flush(struct file *file, fl_owner_t id)
 211 {
 212         struct inode *inode = file->f_path.dentry->d_inode;
 213         struct fuse_conn *fc = get_fuse_conn(inode);
 214         struct fuse_file *ff = file->private_data;
 215         struct fuse_req *req;
 216         struct fuse_flush_in inarg;
 217         int err;
 218
 219         if (is_bad_inode(inode))
 220                 return -EIO;
 221
 222         if (fc->no_flush)
 223                 return 0;
 224
 225         req = fuse_get_req_nofail(fc, file);
 226         memset(&inarg, 0, sizeof(inarg));
 227         inarg.fh = ff->fh;
 228         inarg.lock_owner = fuse_lock_owner_id(fc, id);
 229         req->in.h.opcode = FUSE_FLUSH;
 230         req->in.h.nodeid = get_node_id(inode);
 231         req->in.numargs = 1;
 232         req->in.args[0].size = sizeof(inarg);
 233         req->in.args[0].value = &inarg;
 234         req->force = 1;
 235         request_send(fc, req);
 236         err = req->out.h.error;
 237         fuse_put_request(fc, req);
 238         if (err == -ENOSYS) {
 239                 fc->no_flush = 1;
 240                 err = 0;
 241         }
 242         return err;
 243 }
 244
 245 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
 246                       int isdir)
 247 {
 248         struct inode *inode = de->d_inode;
 249         struct fuse_conn *fc = get_fuse_conn(inode);
 250         struct fuse_file *ff = file->private_data;
 251         struct fuse_req *req;
 252         struct fuse_fsync_in inarg;
 253         int err;
 254
 255         if (is_bad_inode(inode))
 256                 return -EIO;
 257
 258         if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
 259                 return 0;
 260
 261         req = fuse_get_req(fc);
 262         if (IS_ERR(req))
 263                 return PTR_ERR(req);
 264
 265         memset(&inarg, 0, sizeof(inarg));
 266         inarg.fh = ff->fh;
 267         inarg.fsync_flags = datasync ? 1 : 0;
 268         req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
 269         req->in.h.nodeid = get_node_id(inode);
 270         req->in.numargs = 1;
 271         req->in.args[0].size = sizeof(inarg);
 272         req->in.args[0].value = &inarg;
 273         request_send(fc, req);
 274         err = req->out.h.error;
 275         fuse_put_request(fc, req);
 276         if (err == -ENOSYS) {
 277                 if (isdir)
 278                         fc->no_fsyncdir = 1;
 279                 else
 280                         fc->no_fsync = 1;
 281                 err = 0;
 282         }
 283         return err;
 284 }
 285
 286 static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
 287 {
 288         return fuse_fsync_common(file, de, datasync, 0);
 289 }
 290
 291 void fuse_read_fill(struct fuse_req *req, struct fuse_file *ff,
 292                     struct inode *inode, loff_t pos, size_t count, int opcode)
 293 {
 294         struct fuse_read_in *inarg = &req->misc.read_in;
 295
 296         inarg->fh = ff->fh;
 297         inarg->offset = pos;
 298         inarg->size = count;
 299         req->in.h.opcode = opcode;
 300         req->in.h.nodeid = get_node_id(inode);
 301         req->in.numargs = 1;
 302         req->in.args[0].size = sizeof(struct fuse_read_in);
 303         req->in.args[0].value = inarg;
 304         req->out.argpages = 1;
 305         req->out.argvar = 1;
 306         req->out.numargs = 1;
 307         req->out.args[0].size = count;
 308 }
 309
 310 static size_t fuse_send_read(struct fuse_req *req, struct file *file,
 311                              struct inode *inode, loff_t pos, size_t count)
 312 {
 313         struct fuse_conn *fc = get_fuse_conn(inode);
 314         struct fuse_file *ff = file->private_data;
 315         fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
 316         request_send(fc, req);
 317         return req->out.args[0].size;
 318 }
 319
 320 static int fuse_readpage(struct file *file, struct page *page)
 321 {
 322         struct inode *inode = page->mapping->host;
 323         struct fuse_conn *fc = get_fuse_conn(inode);
 324         struct fuse_req *req;
 325         int err;
 326
 327         err = -EIO;
 328         if (is_bad_inode(inode))
 329                 goto out;
 330
 331         req = fuse_get_req(fc);
 332         err = PTR_ERR(req);
 333         if (IS_ERR(req))
 334                 goto out;
 335
 336         req->out.page_zeroing = 1;
 337         req->num_pages = 1;
 338         req->pages[0] = page;
 339         fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
 340         err = req->out.h.error;
 341         fuse_put_request(fc, req);
 342         if (!err)
 343                 SetPageUptodate(page);
 344         fuse_invalidate_attr(inode); /* atime changed */
 345  out:
 346         unlock_page(page);
 347         return err;
 348 }
 349
 350 static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
 351 {
 352         int i;
 353
 354         fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
 355
 356         for (i = 0; i < req->num_pages; i++) {
 357                 struct page *page = req->pages[i];
 358                 if (!req->out.h.error)
 359                         SetPageUptodate(page);
 360                 else
 361                         SetPageError(page);
 362                 unlock_page(page);
 363         }
 364         if (req->ff)
 365                 fuse_file_put(req->ff);
 366         fuse_put_request(fc, req);
 367 }
 368
 369 static void fuse_send_readpages(struct fuse_req *req, struct fuse_file *ff,
 370                                 struct inode *inode)
 371 {
 372         struct fuse_conn *fc = get_fuse_conn(inode);
 373         loff_t pos = page_offset(req->pages[0]);
 374         size_t count = req->num_pages << PAGE_CACHE_SHIFT;
 375         req->out.page_zeroing = 1;
 376         fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
 377         if (fc->async_read) {
 378                 req->ff = fuse_file_get(ff);
 379                 req->end = fuse_readpages_end;
 380                 request_send_background(fc, req);
 381         } else {
 382                 request_send(fc, req);
 383                 fuse_readpages_end(fc, req);
 384         }
 385 }
 386
 387 struct fuse_fill_data {
 388         struct fuse_req *req;
 389         struct fuse_file *ff;
 390         struct inode *inode;
 391 };
 392
 393 static int fuse_readpages_fill(void *_data, struct page *page)
 394 {
 395         struct fuse_fill_data *data = _data;
 396         struct fuse_req *req = data->req;
 397         struct inode *inode = data->inode;
 398         struct fuse_conn *fc = get_fuse_conn(inode);
 399
 400         if (req->num_pages &&
 401             (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
 402              (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
 403              req->pages[req->num_pages - 1]->index + 1 != page->index)) {
 404                 fuse_send_readpages(req, data->ff, inode);
 405                 data->req = req = fuse_get_req(fc);
 406                 if (IS_ERR(req)) {
 407                         unlock_page(page);
 408                         return PTR_ERR(req);
 409                 }
 410         }
 411         req->pages[req->num_pages] = page;
 412         req->num_pages ++;
 413         return 0;
 414 }
 415
 416 static int fuse_readpages(struct file *file, struct address_space *mapping,
 417                           struct list_head *pages, unsigned nr_pages)
 418 {
 419         struct inode *inode = mapping->host;
 420         struct fuse_conn *fc = get_fuse_conn(inode);
 421         struct fuse_fill_data data;
 422         int err;
 423
 424         err = -EIO;
 425         if (is_bad_inode(inode))
 426                 goto out;
 427
 428         data.ff = file->private_data;
 429         data.inode = inode;
 430         data.req = fuse_get_req(fc);
 431         err = PTR_ERR(data.req);
 432         if (IS_ERR(data.req))
 433                 goto out;
 434
 435         err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
 436         if (!err) {
 437                 if (data.req->num_pages)
 438                         fuse_send_readpages(data.req, data.ff, inode);
 439                 else
 440                         fuse_put_request(fc, data.req);
 441         }
 442 out:
 443         return err;
 444 }
 445
 446 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
 447                               struct inode *inode, loff_t pos, size_t count)
 448 {
 449         struct fuse_conn *fc = get_fuse_conn(inode);
 450         struct fuse_file *ff = file->private_data;
 451         struct fuse_write_in inarg;
 452         struct fuse_write_out outarg;
 453
 454         memset(&inarg, 0, sizeof(struct fuse_write_in));
 455         inarg.fh = ff->fh;
 456         inarg.offset = pos;
 457         inarg.size = count;
 458         req->in.h.opcode = FUSE_WRITE;
 459         req->in.h.nodeid = get_node_id(inode);
 460         req->in.argpages = 1;
 461         req->in.numargs = 2;
 462         req->in.args[0].size = sizeof(struct fuse_write_in);
 463         req->in.args[0].value = &inarg;
 464         req->in.args[1].size = count;
 465         req->out.numargs = 1;
 466         req->out.args[0].size = sizeof(struct fuse_write_out);
 467         req->out.args[0].value = &outarg;
 468         request_send(fc, req);
 469         return outarg.size;
 470 }
 471
 472 static int fuse_write_begin(struct file *file, struct address_space *mapping,
 473                         loff_t pos, unsigned len, unsigned flags,
 474                         struct page **pagep, void **fsdata)
 475 {
 476         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 477
 478         *pagep = __grab_cache_page(mapping, index);
 479         if (!*pagep)
 480                 return -ENOMEM;
 481         return 0;
 482 }
 483
 484 static int fuse_buffered_write(struct file *file, struct inode *inode,
 485                                loff_t pos, unsigned count, struct page *page)
 486 {
 487         int err;
 488         size_t nres;
 489         struct fuse_conn *fc = get_fuse_conn(inode);
 490         struct fuse_inode *fi = get_fuse_inode(inode);
 491         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
 492         struct fuse_req *req;
 493
 494         if (is_bad_inode(inode))
 495                 return -EIO;
 496
 497         req = fuse_get_req(fc);
 498         if (IS_ERR(req))
 499                 return PTR_ERR(req);
 500
 501         req->num_pages = 1;
 502         req->pages[0] = page;
 503         req->page_offset = offset;
 504         nres = fuse_send_write(req, file, inode, pos, count);
 505         err = req->out.h.error;
 506         fuse_put_request(fc, req);
 507         if (!err && !nres)
 508                 err = -EIO;
 509         if (!err) {
 510                 pos += nres;
 511                 spin_lock(&fc->lock);
 512                 fi->attr_version = ++fc->attr_version;
 513                 if (pos > inode->i_size)
 514                         i_size_write(inode, pos);
 515                 spin_unlock(&fc->lock);
 516
 517                 if (count == PAGE_CACHE_SIZE)
 518                         SetPageUptodate(page);
 519         }
 520         fuse_invalidate_attr(inode);
 521         return err ? err : nres;
 522 }
 523
 524 static int fuse_write_end(struct file *file, struct address_space *mapping,
 525                         loff_t pos, unsigned len, unsigned copied,
 526                         struct page *page, void *fsdata)
 527 {
 528         struct inode *inode = mapping->host;
 529         int res = 0;
 530
 531         if (copied)
 532                 res = fuse_buffered_write(file, inode, pos, copied, page);
 533
 534         unlock_page(page);
 535         page_cache_release(page);
 536         return res;
 537 }
 538
 539 static void fuse_release_user_pages(struct fuse_req *req, int write)
 540 {
 541         unsigned i;
 542
 543         for (i = 0; i < req->num_pages; i++) {
 544                 struct page *page = req->pages[i];
 545                 if (write)
 546                         set_page_dirty_lock(page);
 547                 put_page(page);
 548         }
 549 }
 550
 551 static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
 552                                unsigned nbytes, int write)
 553 {
 554         unsigned long user_addr = (unsigned long) buf;
 555         unsigned offset = user_addr & ~PAGE_MASK;
 556         int npages;
 557
 558         /* This doesn't work with nfsd */
 559         if (!current->mm)
 560                 return -EPERM;
 561
 562         nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
 563         npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
 564         npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
 565         down_read(&current->mm->mmap_sem);
 566         npages = get_user_pages(current, current->mm, user_addr, npages, write,
 567                                 0, req->pages, NULL);
 568         up_read(&current->mm->mmap_sem);
 569         if (npages < 0)
 570                 return npages;
 571
 572         req->num_pages = npages;
 573         req->page_offset = offset;
 574         return 0;
 575 }
 576
 577 static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
 578                               size_t count, loff_t *ppos, int write)
 579 {
 580         struct inode *inode = file->f_path.dentry->d_inode;
 581         struct fuse_conn *fc = get_fuse_conn(inode);
 582         size_t nmax = write ? fc->max_write : fc->max_read;
 583         loff_t pos = *ppos;
 584         ssize_t res = 0;
 585         struct fuse_req *req;
 586
 587         if (is_bad_inode(inode))
 588                 return -EIO;
 589
 590         req = fuse_get_req(fc);
 591         if (IS_ERR(req))
 592                 return PTR_ERR(req);
 593
 594         while (count) {
 595                 size_t nres;
 596                 size_t nbytes = min(count, nmax);
 597                 int err = fuse_get_user_pages(req, buf, nbytes, !write);
 598                 if (err) {
 599                         res = err;
 600                         break;
 601                 }
 602                 nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
 603                 nbytes = min(count, nbytes);
 604                 if (write)
 605                         nres = fuse_send_write(req, file, inode, pos, nbytes);
 606                 else
 607                         nres = fuse_send_read(req, file, inode, pos, nbytes);
 608                 fuse_release_user_pages(req, !write);
 609                 if (req->out.h.error) {
 610                         if (!res)
 611                                 res = req->out.h.error;
 612                         break;
 613                 } else if (nres > nbytes) {
 614                         res = -EIO;
 615                         break;
 616                 }
 617                 count -= nres;
 618                 res += nres;
 619                 pos += nres;
 620                 buf += nres;
 621                 if (nres != nbytes)
 622                         break;
 623                 if (count) {
 624                         fuse_put_request(fc, req);
 625                         req = fuse_get_req(fc);
 626                         if (IS_ERR(req))
 627                                 break;
 628                 }
 629         }
 630         fuse_put_request(fc, req);
 631         if (res > 0) {
 632                 if (write) {
 633                         spin_lock(&fc->lock);
 634                         if (pos > inode->i_size)
 635                                 i_size_write(inode, pos);
 636                         spin_unlock(&fc->lock);
 637                 }
 638                 *ppos = pos;
 639         }
 640         fuse_invalidate_attr(inode);
 641
 642         return res;
 643 }
 644
 645 static ssize_t fuse_direct_read(struct file *file, char __user *buf,
 646                                      size_t count, loff_t *ppos)
 647 {
 648         return fuse_direct_io(file, buf, count, ppos, 0);
 649 }
 650
 651 static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
 652                                  size_t count, loff_t *ppos)
 653 {
 654         struct inode *inode = file->f_path.dentry->d_inode;
 655         ssize_t res;
 656         /* Don't allow parallel writes to the same file */
 657         mutex_lock(&inode->i_mutex);
 658         res = generic_write_checks(file, ppos, &count, 0);
 659         if (!res)
 660                 res = fuse_direct_io(file, buf, count, ppos, 1);
 661         mutex_unlock(&inode->i_mutex);
 662         return res;
 663 }
 664
 665 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
 666 {
 667         if ((vma->vm_flags & VM_SHARED)) {
 668                 if ((vma->vm_flags & VM_WRITE))
 669                         return -ENODEV;
 670                 else
 671                         vma->vm_flags &= ~VM_MAYWRITE;
 672         }
 673         return generic_file_mmap(file, vma);
 674 }
 675
 676 static int fuse_set_page_dirty(struct page *page)
 677 {
 678         printk("fuse_set_page_dirty: should not happen\n");
 679         dump_stack();
 680         return 0;
 681 }
 682
 683 static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
 684                                   struct file_lock *fl)
 685 {
 686         switch (ffl->type) {
 687         case F_UNLCK:
 688                 break;
 689
 690         case F_RDLCK:
 691         case F_WRLCK:
 692                 if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
 693                     ffl->end < ffl->start)
 694                         return -EIO;
 695
 696                 fl->fl_start = ffl->start;
 697                 fl->fl_end = ffl->end;
 698                 fl->fl_pid = ffl->pid;
 699                 break;
 700
 701         default:
 702                 return -EIO;
 703         }
 704         fl->fl_type = ffl->type;
 705         return 0;
 706 }
 707
 708 static void fuse_lk_fill(struct fuse_req *req, struct file *file,
 709                          const struct file_lock *fl, int opcode, pid_t pid,
 710                          int flock)
 711 {
 712         struct inode *inode = file->f_path.dentry->d_inode;
 713         struct fuse_conn *fc = get_fuse_conn(inode);
 714         struct fuse_file *ff = file->private_data;
 715         struct fuse_lk_in *arg = &req->misc.lk_in;
 716
 717         arg->fh = ff->fh;
 718         arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
 719         arg->lk.start = fl->fl_start;
 720         arg->lk.end = fl->fl_end;
 721         arg->lk.type = fl->fl_type;
 722         arg->lk.pid = pid;
 723         if (flock)
 724                 arg->lk_flags |= FUSE_LK_FLOCK;
 725         req->in.h.opcode = opcode;
 726         req->in.h.nodeid = get_node_id(inode);
 727         req->in.numargs = 1;
 728         req->in.args[0].size = sizeof(*arg);
 729         req->in.args[0].value = arg;
 730 }
 731
 732 static int fuse_getlk(struct file *file, struct file_lock *fl)
 733 {
 734         struct inode *inode = file->f_path.dentry->d_inode;
 735         struct fuse_conn *fc = get_fuse_conn(inode);
 736         struct fuse_req *req;
 737         struct fuse_lk_out outarg;
 738         int err;
 739
 740         req = fuse_get_req(fc);
 741         if (IS_ERR(req))
 742                 return PTR_ERR(req);
 743
 744         fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
 745         req->out.numargs = 1;
 746         req->out.args[0].size = sizeof(outarg);
 747         req->out.args[0].value = &outarg;
 748         request_send(fc, req);
 749         err = req->out.h.error;
 750         fuse_put_request(fc, req);
 751         if (!err)
 752                 err = convert_fuse_file_lock(&outarg.lk, fl);
 753
 754         return err;
 755 }
 756
 757 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 758 {
 759         struct inode *inode = file->f_path.dentry->d_inode;
 760         struct fuse_conn *fc = get_fuse_conn(inode);
 761         struct fuse_req *req;
 762         int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
 763         pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
 764         int err;
 765
 766         /* Unlock on close is handled by the flush method */
 767         if (fl->fl_flags & FL_CLOSE)
 768                 return 0;
 769
 770         req = fuse_get_req(fc);
 771         if (IS_ERR(req))
 772                 return PTR_ERR(req);
 773
 774         fuse_lk_fill(req, file, fl, opcode, pid, flock);
 775         request_send(fc, req);
 776         err = req->out.h.error;
 777         /* locking is restartable */
 778         if (err == -EINTR)
 779                 err = -ERESTARTSYS;
 780         fuse_put_request(fc, req);
 781         return err;
 782 }
 783
 784 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
 785 {
 786         struct inode *inode = file->f_path.dentry->d_inode;
 787         struct fuse_conn *fc = get_fuse_conn(inode);
 788         int err;
 789
 790         if (cmd == F_GETLK) {
 791                 if (fc->no_lock) {
 792                         posix_test_lock(file, fl);
 793                         err = 0;
 794                 } else
 795                         err = fuse_getlk(file, fl);
 796         } else {
 797                 if (fc->no_lock)
 798                         err = posix_lock_file_wait(file, fl);
 799                 else
 800                         err = fuse_setlk(file, fl, 0);
 801         }
 802         return err;
 803 }
 804
 805 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
 806 {
 807         struct inode *inode = file->f_path.dentry->d_inode;
 808         struct fuse_conn *fc = get_fuse_conn(inode);
 809         int err;
 810
 811         if (fc->no_lock) {
 812                 err = flock_lock_file_wait(file, fl);
 813         } else {
 814                 /* emulate flock with POSIX locks */
 815                 fl->fl_owner = (fl_owner_t) file;
 816                 err = fuse_setlk(file, fl, 1);
 817         }
 818
 819         return err;
 820 }
 821
 822 static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
 823 {
 824         struct inode *inode = mapping->host;
 825         struct fuse_conn *fc = get_fuse_conn(inode);
 826         struct fuse_req *req;
 827         struct fuse_bmap_in inarg;
 828         struct fuse_bmap_out outarg;
 829         int err;
 830
 831         if (!inode->i_sb->s_bdev || fc->no_bmap)
 832                 return 0;
 833
 834         req = fuse_get_req(fc);
 835         if (IS_ERR(req))
 836                 return 0;
 837
 838         memset(&inarg, 0, sizeof(inarg));
 839         inarg.block = block;
 840         inarg.blocksize = inode->i_sb->s_blocksize;
 841         req->in.h.opcode = FUSE_BMAP;
 842         req->in.h.nodeid = get_node_id(inode);
 843         req->in.numargs = 1;
 844         req->in.args[0].size = sizeof(inarg);
 845         req->in.args[0].value = &inarg;
 846         req->out.numargs = 1;
 847         req->out.args[0].size = sizeof(outarg);
 848         req->out.args[0].value = &outarg;
 849         request_send(fc, req);
 850         err = req->out.h.error;
 851         fuse_put_request(fc, req);
 852         if (err == -ENOSYS)
 853                 fc->no_bmap = 1;
 854
 855         return err ? 0 : outarg.block;
 856 }
 857
 858 static const struct file_operations fuse_file_operations = {
 859         .llseek         = generic_file_llseek,
 860         .read           = do_sync_read,
 861         .aio_read       = generic_file_aio_read,
 862         .write          = do_sync_write,
 863         .aio_write      = generic_file_aio_write,
 864         .mmap           = fuse_file_mmap,
 865         .open           = fuse_open,
 866         .flush          = fuse_flush,
 867         .release        = fuse_release,
 868         .fsync          = fuse_fsync,
 869         .lock           = fuse_file_lock,
 870         .flock          = fuse_file_flock,
 871         .splice_read    = generic_file_splice_read,
 872 };
 873
 874 static const struct file_operations fuse_direct_io_file_operations = {
 875         .llseek         = generic_file_llseek,
 876         .read           = fuse_direct_read,
 877         .write          = fuse_direct_write,
 878         .open           = fuse_open,
 879         .flush          = fuse_flush,
 880         .release        = fuse_release,
 881         .fsync          = fuse_fsync,
 882         .lock           = fuse_file_lock,
 883         .flock          = fuse_file_flock,
 884         /* no mmap and splice_read */
 885 };
 886
 887 static const struct address_space_operations fuse_file_aops  = {
 888         .readpage       = fuse_readpage,
 889         .write_begin    = fuse_write_begin,
 890         .write_end      = fuse_write_end,
 891         .readpages      = fuse_readpages,
 892         .set_page_dirty = fuse_set_page_dirty,
 893         .bmap           = fuse_bmap,
 894 };
 895
 896 void fuse_init_file_inode(struct inode *inode)
 897 {
 898         inode->i_fop = &fuse_file_operations;
 899         inode->i_data.a_ops = &fuse_file_aops;
 900 }