1 /* 2 * linux/fs/nfs/file.c 3 * 4 * Copyright (C) 1992 Rick Sladkey 5 * 6 * Changes Copyright (C) 1994 by Florian La Roche 7 * - Do not copy data too often around in the kernel. 8 * - In nfs_file_read the return value of kmalloc wasn't checked. 9 * - Put in a better version of read look-ahead buffering. Original idea 10 * and implementation by Wai S Kok elekokws@ee.nus.sg. 11 * 12 * Expire cache on write to a file by Wai S Kok (Oct 1994). 13 * 14 * Total rewrite of read side for new NFS buffer cache.. Linus. 15 * 16 * nfs regular file handling functions 17 */ 18 19 #include <linux/time.h> 20 #include <linux/kernel.h> 21 #include <linux/errno.h> 22 #include <linux/fcntl.h> 23 #include <linux/stat.h> 24 #include <linux/nfs_fs.h> 25 #include <linux/nfs_mount.h> 26 #include <linux/mm.h> 27 #include <linux/slab.h> 28 #include <linux/pagemap.h> 29 #include <linux/aio.h> 30 31 #include <asm/uaccess.h> 32 #include <asm/system.h> 33 34 #include "delegation.h" 35 #include "internal.h" 36 #include "iostat.h" 37 #include "fscache.h" 38 39 #define NFSDBG_FACILITY NFSDBG_FILE 40 41 static int nfs_file_open(struct inode *, struct file *); 42 static int nfs_file_release(struct inode *, struct file *); 43 static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin); 44 static int nfs_file_mmap(struct file *, struct vm_area_struct *); 45 static ssize_t nfs_file_splice_read(struct file *filp, loff_t *ppos, 46 struct pipe_inode_info *pipe, 47 size_t count, unsigned int flags); 48 static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov, 49 unsigned long nr_segs, loff_t pos); 50 static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe, 51 struct file *filp, loff_t *ppos, 52 size_t count, unsigned int flags); 53 static ssize_t nfs_file_write(struct kiocb *, const struct iovec *iov, 54 unsigned long nr_segs, loff_t pos); 55 static int nfs_file_flush(struct file *, fl_owner_t id); 56 static int nfs_file_fsync(struct file *, struct dentry *dentry, int datasync); 57 static int nfs_check_flags(int flags); 58 static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl); 59 static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl); 60 static int nfs_setlease(struct file *file, long arg, struct file_lock **fl); 61 62 static struct vm_operations_struct nfs_file_vm_ops; 63 64 const struct file_operations nfs_file_operations = { 65 .llseek = nfs_file_llseek, 66 .read = do_sync_read, 67 .write = do_sync_write, 68 .aio_read = nfs_file_read, 69 .aio_write = nfs_file_write, 70 .mmap = nfs_file_mmap, 71 .open = nfs_file_open, 72 .flush = nfs_file_flush, 73 .release = nfs_file_release, 74 .fsync = nfs_file_fsync, 75 .lock = nfs_lock, 76 .flock = nfs_flock, 77 .splice_read = nfs_file_splice_read, 78 .splice_write = nfs_file_splice_write, 79 .check_flags = nfs_check_flags, 80 .setlease = nfs_setlease, 81 }; 82 83 const struct inode_operations nfs_file_inode_operations = { 84 .permission = nfs_permission, 85 .getattr = nfs_getattr, 86 .setattr = nfs_setattr, 87 }; 88 89 #ifdef CONFIG_NFS_V3 90 const struct inode_operations nfs3_file_inode_operations = { 91 .permission = nfs_permission, 92 .getattr = nfs_getattr, 93 .setattr = nfs_setattr, 94 .listxattr = nfs3_listxattr, 95 .getxattr = nfs3_getxattr, 96 .setxattr = nfs3_setxattr, 97 .removexattr = nfs3_removexattr, 98 }; 99 #endif /* CONFIG_NFS_v3 */ 100 101 /* Hack for future NFS swap support */ 102 #ifndef IS_SWAPFILE 103 # define IS_SWAPFILE(inode) (0) 104 #endif 105 106 static int nfs_check_flags(int flags) 107 { 108 if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT)) 109 return -EINVAL; 110 111 return 0; 112 } 113 114 /* 115 * Open file 116 */ 117 static int 118 nfs_file_open(struct inode *inode, struct file *filp) 119 { 120 int res; 121 122 dprintk("NFS: open file(%s/%s)\n", 123 filp->f_path.dentry->d_parent->d_name.name, 124 filp->f_path.dentry->d_name.name); 125 126 res = nfs_check_flags(filp->f_flags); 127 if (res) 128 return res; 129 130 nfs_inc_stats(inode, NFSIOS_VFSOPEN); 131 res = nfs_open(inode, filp); 132 return res; 133 } 134 135 static int 136 nfs_file_release(struct inode *inode, struct file *filp) 137 { 138 struct dentry *dentry = filp->f_path.dentry; 139 140 dprintk("NFS: release(%s/%s)\n", 141 dentry->d_parent->d_name.name, 142 dentry->d_name.name); 143 144 nfs_inc_stats(inode, NFSIOS_VFSRELEASE); 145 return nfs_release(inode, filp); 146 } 147 148 /** 149 * nfs_revalidate_size - Revalidate the file size 150 * @inode - pointer to inode struct 151 * @file - pointer to struct file 152 * 153 * Revalidates the file length. This is basically a wrapper around 154 * nfs_revalidate_inode() that takes into account the fact that we may 155 * have cached writes (in which case we don't care about the server's 156 * idea of what the file length is), or O_DIRECT (in which case we 157 * shouldn't trust the cache). 158 */ 159 static int nfs_revalidate_file_size(struct inode *inode, struct file *filp) 160 { 161 struct nfs_server *server = NFS_SERVER(inode); 162 struct nfs_inode *nfsi = NFS_I(inode); 163 164 if (server->flags & NFS_MOUNT_NOAC) 165 goto force_reval; 166 if (filp->f_flags & O_DIRECT) 167 goto force_reval; 168 if (nfsi->npages != 0) 169 return 0; 170 if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode)) 171 return 0; 172 force_reval: 173 return __nfs_revalidate_inode(server, inode); 174 } 175 176 static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin) 177 { 178 loff_t loff; 179 180 dprintk("NFS: llseek file(%s/%s, %lld, %d)\n", 181 filp->f_path.dentry->d_parent->d_name.name, 182 filp->f_path.dentry->d_name.name, 183 offset, origin); 184 185 /* origin == SEEK_END => we must revalidate the cached file length */ 186 if (origin == SEEK_END) { 187 struct inode *inode = filp->f_mapping->host; 188 189 int retval = nfs_revalidate_file_size(inode, filp); 190 if (retval < 0) 191 return (loff_t)retval; 192 193 spin_lock(&inode->i_lock); 194 loff = generic_file_llseek_unlocked(filp, offset, origin); 195 spin_unlock(&inode->i_lock); 196 } else 197 loff = generic_file_llseek_unlocked(filp, offset, origin); 198 return loff; 199 } 200 201 /* 202 * Helper for nfs_file_flush() and nfs_file_fsync() 203 * 204 * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to 205 * disk, but it retrieves and clears ctx->error after synching, despite 206 * the two being set at the same time in nfs_context_set_write_error(). 207 * This is because the former is used to notify the _next_ call to 208 * nfs_file_write() that a write error occured, and hence cause it to 209 * fall back to doing a synchronous write. 210 */ 211 static int nfs_do_fsync(struct nfs_open_context *ctx, struct inode *inode) 212 { 213 int have_error, status; 214 int ret = 0; 215 216 have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); 217 status = nfs_wb_all(inode); 218 have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); 219 if (have_error) 220 ret = xchg(&ctx->error, 0); 221 if (!ret) 222 ret = status; 223 return ret; 224 } 225 226 /* 227 * Flush all dirty pages, and check for write errors. 228 */ 229 static int 230 nfs_file_flush(struct file *file, fl_owner_t id) 231 { 232 struct nfs_open_context *ctx = nfs_file_open_context(file); 233 struct dentry *dentry = file->f_path.dentry; 234 struct inode *inode = dentry->d_inode; 235 236 dprintk("NFS: flush(%s/%s)\n", 237 dentry->d_parent->d_name.name, 238 dentry->d_name.name); 239 240 if ((file->f_mode & FMODE_WRITE) == 0) 241 return 0; 242 nfs_inc_stats(inode, NFSIOS_VFSFLUSH); 243 244 /* Flush writes to the server and return any errors */ 245 return nfs_do_fsync(ctx, inode); 246 } 247 248 static ssize_t 249 nfs_file_read(struct kiocb *iocb, const struct iovec *iov, 250 unsigned long nr_segs, loff_t pos) 251 { 252 struct dentry * dentry = iocb->ki_filp->f_path.dentry; 253 struct inode * inode = dentry->d_inode; 254 ssize_t result; 255 size_t count = iov_length(iov, nr_segs); 256 257 if (iocb->ki_filp->f_flags & O_DIRECT) 258 return nfs_file_direct_read(iocb, iov, nr_segs, pos); 259 260 dprintk("NFS: read(%s/%s, %lu@%lu)\n", 261 dentry->d_parent->d_name.name, dentry->d_name.name, 262 (unsigned long) count, (unsigned long) pos); 263 264 result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping); 265 nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count); 266 if (!result) 267 result = generic_file_aio_read(iocb, iov, nr_segs, pos); 268 return result; 269 } 270 271 static ssize_t 272 nfs_file_splice_read(struct file *filp, loff_t *ppos, 273 struct pipe_inode_info *pipe, size_t count, 274 unsigned int flags) 275 { 276 struct dentry *dentry = filp->f_path.dentry; 277 struct inode *inode = dentry->d_inode; 278 ssize_t res; 279 280 dprintk("NFS: splice_read(%s/%s, %lu@%Lu)\n", 281 dentry->d_parent->d_name.name, dentry->d_name.name, 282 (unsigned long) count, (unsigned long long) *ppos); 283 284 res = nfs_revalidate_mapping(inode, filp->f_mapping); 285 if (!res) 286 res = generic_file_splice_read(filp, ppos, pipe, count, flags); 287 return res; 288 } 289 290 static int 291 nfs_file_mmap(struct file * file, struct vm_area_struct * vma) 292 { 293 struct dentry *dentry = file->f_path.dentry; 294 struct inode *inode = dentry->d_inode; 295 int status; 296 297 dprintk("NFS: mmap(%s/%s)\n", 298 dentry->d_parent->d_name.name, dentry->d_name.name); 299 300 /* Note: generic_file_mmap() returns ENOSYS on nommu systems 301 * so we call that before revalidating the mapping 302 */ 303 status = generic_file_mmap(file, vma); 304 if (!status) { 305 vma->vm_ops = &nfs_file_vm_ops; 306 status = nfs_revalidate_mapping(inode, file->f_mapping); 307 } 308 return status; 309 } 310 311 /* 312 * Flush any dirty pages for this process, and check for write errors. 313 * The return status from this call provides a reliable indication of 314 * whether any write errors occurred for this process. 315 */ 316 static int 317 nfs_file_fsync(struct file *file, struct dentry *dentry, int datasync) 318 { 319 struct nfs_open_context *ctx = nfs_file_open_context(file); 320 struct inode *inode = dentry->d_inode; 321 322 dprintk("NFS: fsync file(%s/%s) datasync %d\n", 323 dentry->d_parent->d_name.name, dentry->d_name.name, 324 datasync); 325 326 nfs_inc_stats(inode, NFSIOS_VFSFSYNC); 327 return nfs_do_fsync(ctx, inode); 328 } 329 330 /* 331 * This does the "real" work of the write. We must allocate and lock the 332 * page to be sent back to the generic routine, which then copies the 333 * data from user space. 334 * 335 * If the writer ends up delaying the write, the writer needs to 336 * increment the page use counts until he is done with the page. 337 */ 338 static int nfs_write_begin(struct file *file, struct address_space *mapping, 339 loff_t pos, unsigned len, unsigned flags, 340 struct page **pagep, void **fsdata) 341 { 342 int ret; 343 pgoff_t index; 344 struct page *page; 345 index = pos >> PAGE_CACHE_SHIFT; 346 347 dfprintk(PAGECACHE, "NFS: write_begin(%s/%s(%ld), %u@%lld)\n", 348 file->f_path.dentry->d_parent->d_name.name, 349 file->f_path.dentry->d_name.name, 350 mapping->host->i_ino, len, (long long) pos); 351 352 /* 353 * Prevent starvation issues if someone is doing a consistency 354 * sync-to-disk 355 */ 356 ret = wait_on_bit(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING, 357 nfs_wait_bit_killable, TASK_KILLABLE); 358 if (ret) 359 return ret; 360 361 page = grab_cache_page_write_begin(mapping, index, flags); 362 if (!page) 363 return -ENOMEM; 364 *pagep = page; 365 366 ret = nfs_flush_incompatible(file, page); 367 if (ret) { 368 unlock_page(page); 369 page_cache_release(page); 370 } 371 return ret; 372 } 373 374 static int nfs_write_end(struct file *file, struct address_space *mapping, 375 loff_t pos, unsigned len, unsigned copied, 376 struct page *page, void *fsdata) 377 { 378 unsigned offset = pos & (PAGE_CACHE_SIZE - 1); 379 int status; 380 381 dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n", 382 file->f_path.dentry->d_parent->d_name.name, 383 file->f_path.dentry->d_name.name, 384 mapping->host->i_ino, len, (long long) pos); 385 386 /* 387 * Zero any uninitialised parts of the page, and then mark the page 388 * as up to date if it turns out that we're extending the file. 389 */ 390 if (!PageUptodate(page)) { 391 unsigned pglen = nfs_page_length(page); 392 unsigned end = offset + len; 393 394 if (pglen == 0) { 395 zero_user_segments(page, 0, offset, 396 end, PAGE_CACHE_SIZE); 397 SetPageUptodate(page); 398 } else if (end >= pglen) { 399 zero_user_segment(page, end, PAGE_CACHE_SIZE); 400 if (offset == 0) 401 SetPageUptodate(page); 402 } else 403 zero_user_segment(page, pglen, PAGE_CACHE_SIZE); 404 } 405 406 status = nfs_updatepage(file, page, offset, copied); 407 408 unlock_page(page); 409 page_cache_release(page); 410 411 if (status < 0) 412 return status; 413 return copied; 414 } 415 416 /* 417 * Partially or wholly invalidate a page 418 * - Release the private state associated with a page if undergoing complete 419 * page invalidation 420 * - Called if either PG_private or PG_fscache is set on the page 421 * - Caller holds page lock 422 */ 423 static void nfs_invalidate_page(struct page *page, unsigned long offset) 424 { 425 dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset); 426 427 if (offset != 0) 428 return; 429 /* Cancel any unstarted writes on this page */ 430 nfs_wb_page_cancel(page->mapping->host, page); 431 432 nfs_fscache_invalidate_page(page, page->mapping->host); 433 } 434 435 /* 436 * Attempt to release the private state associated with a page 437 * - Called if either PG_private or PG_fscache is set on the page 438 * - Caller holds page lock 439 * - Return true (may release page) or false (may not) 440 */ 441 static int nfs_release_page(struct page *page, gfp_t gfp) 442 { 443 dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); 444 445 /* If PagePrivate() is set, then the page is not freeable */ 446 if (PagePrivate(page)) 447 return 0; 448 return nfs_fscache_release_page(page, gfp); 449 } 450 451 /* 452 * Attempt to clear the private state associated with a page when an error 453 * occurs that requires the cached contents of an inode to be written back or 454 * destroyed 455 * - Called if either PG_private or fscache is set on the page 456 * - Caller holds page lock 457 * - Return 0 if successful, -error otherwise 458 */ 459 static int nfs_launder_page(struct page *page) 460 { 461 struct inode *inode = page->mapping->host; 462 struct nfs_inode *nfsi = NFS_I(inode); 463 464 dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n", 465 inode->i_ino, (long long)page_offset(page)); 466 467 nfs_fscache_wait_on_page_write(nfsi, page); 468 return nfs_wb_page(inode, page); 469 } 470 471 const struct address_space_operations nfs_file_aops = { 472 .readpage = nfs_readpage, 473 .readpages = nfs_readpages, 474 .set_page_dirty = __set_page_dirty_nobuffers, 475 .writepage = nfs_writepage, 476 .writepages = nfs_writepages, 477 .write_begin = nfs_write_begin, 478 .write_end = nfs_write_end, 479 .invalidatepage = nfs_invalidate_page, 480 .releasepage = nfs_release_page, 481 .direct_IO = nfs_direct_IO, 482 .launder_page = nfs_launder_page, 483 }; 484 485 /* 486 * Notification that a PTE pointing to an NFS page is about to be made 487 * writable, implying that someone is about to modify the page through a 488 * shared-writable mapping 489 */ 490 static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 491 { 492 struct page *page = vmf->page; 493 struct file *filp = vma->vm_file; 494 struct dentry *dentry = filp->f_path.dentry; 495 unsigned pagelen; 496 int ret = -EINVAL; 497 struct address_space *mapping; 498 499 dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n", 500 dentry->d_parent->d_name.name, dentry->d_name.name, 501 filp->f_mapping->host->i_ino, 502 (long long)page_offset(page)); 503 504 /* make sure the cache has finished storing the page */ 505 nfs_fscache_wait_on_page_write(NFS_I(dentry->d_inode), page); 506 507 lock_page(page); 508 mapping = page->mapping; 509 if (mapping != dentry->d_inode->i_mapping) 510 goto out_unlock; 511 512 ret = 0; 513 pagelen = nfs_page_length(page); 514 if (pagelen == 0) 515 goto out_unlock; 516 517 ret = nfs_flush_incompatible(filp, page); 518 if (ret != 0) 519 goto out_unlock; 520 521 ret = nfs_updatepage(filp, page, 0, pagelen); 522 out_unlock: 523 if (!ret) 524 return VM_FAULT_LOCKED; 525 unlock_page(page); 526 return VM_FAULT_SIGBUS; 527 } 528 529 static struct vm_operations_struct nfs_file_vm_ops = { 530 .fault = filemap_fault, 531 .page_mkwrite = nfs_vm_page_mkwrite, 532 }; 533 534 static int nfs_need_sync_write(struct file *filp, struct inode *inode) 535 { 536 struct nfs_open_context *ctx; 537 538 if (IS_SYNC(inode) || (filp->f_flags & O_SYNC)) 539 return 1; 540 ctx = nfs_file_open_context(filp); 541 if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags)) 542 return 1; 543 return 0; 544 } 545 546 static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov, 547 unsigned long nr_segs, loff_t pos) 548 { 549 struct dentry * dentry = iocb->ki_filp->f_path.dentry; 550 struct inode * inode = dentry->d_inode; 551 ssize_t result; 552 size_t count = iov_length(iov, nr_segs); 553 554 if (iocb->ki_filp->f_flags & O_DIRECT) 555 return nfs_file_direct_write(iocb, iov, nr_segs, pos); 556 557 dprintk("NFS: write(%s/%s, %lu@%Ld)\n", 558 dentry->d_parent->d_name.name, dentry->d_name.name, 559 (unsigned long) count, (long long) pos); 560 561 result = -EBUSY; 562 if (IS_SWAPFILE(inode)) 563 goto out_swapfile; 564 /* 565 * O_APPEND implies that we must revalidate the file length. 566 */ 567 if (iocb->ki_filp->f_flags & O_APPEND) { 568 result = nfs_revalidate_file_size(inode, iocb->ki_filp); 569 if (result) 570 goto out; 571 } 572 573 result = count; 574 if (!count) 575 goto out; 576 577 nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count); 578 result = generic_file_aio_write(iocb, iov, nr_segs, pos); 579 /* Return error values for O_SYNC and IS_SYNC() */ 580 if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) { 581 int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode); 582 if (err < 0) 583 result = err; 584 } 585 out: 586 return result; 587 588 out_swapfile: 589 printk(KERN_INFO "NFS: attempt to write to active swap file!\n"); 590 goto out; 591 } 592 593 static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe, 594 struct file *filp, loff_t *ppos, 595 size_t count, unsigned int flags) 596 { 597 struct dentry *dentry = filp->f_path.dentry; 598 struct inode *inode = dentry->d_inode; 599 ssize_t ret; 600 601 dprintk("NFS splice_write(%s/%s, %lu@%llu)\n", 602 dentry->d_parent->d_name.name, dentry->d_name.name, 603 (unsigned long) count, (unsigned long long) *ppos); 604 605 /* 606 * The combination of splice and an O_APPEND destination is disallowed. 607 */ 608 609 nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count); 610 611 ret = generic_file_splice_write(pipe, filp, ppos, count, flags); 612 if (ret >= 0 && nfs_need_sync_write(filp, inode)) { 613 int err = nfs_do_fsync(nfs_file_open_context(filp), inode); 614 if (err < 0) 615 ret = err; 616 } 617 return ret; 618 } 619 620 static int do_getlk(struct file *filp, int cmd, struct file_lock *fl) 621 { 622 struct inode *inode = filp->f_mapping->host; 623 int status = 0; 624 625 /* Try local locking first */ 626 posix_test_lock(filp, fl); 627 if (fl->fl_type != F_UNLCK) { 628 /* found a conflict */ 629 goto out; 630 } 631 632 if (nfs_have_delegation(inode, FMODE_READ)) 633 goto out_noconflict; 634 635 if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM) 636 goto out_noconflict; 637 638 status = NFS_PROTO(inode)->lock(filp, cmd, fl); 639 out: 640 return status; 641 out_noconflict: 642 fl->fl_type = F_UNLCK; 643 goto out; 644 } 645 646 static int do_vfs_lock(struct file *file, struct file_lock *fl) 647 { 648 int res = 0; 649 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { 650 case FL_POSIX: 651 res = posix_lock_file_wait(file, fl); 652 break; 653 case FL_FLOCK: 654 res = flock_lock_file_wait(file, fl); 655 break; 656 default: 657 BUG(); 658 } 659 if (res < 0) 660 dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager" 661 " - error %d!\n", 662 __func__, res); 663 return res; 664 } 665 666 static int do_unlk(struct file *filp, int cmd, struct file_lock *fl) 667 { 668 struct inode *inode = filp->f_mapping->host; 669 int status; 670 671 /* 672 * Flush all pending writes before doing anything 673 * with locks.. 674 */ 675 nfs_sync_mapping(filp->f_mapping); 676 677 /* NOTE: special case 678 * If we're signalled while cleaning up locks on process exit, we 679 * still need to complete the unlock. 680 */ 681 /* Use local locking if mounted with "-onolock" */ 682 if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) 683 status = NFS_PROTO(inode)->lock(filp, cmd, fl); 684 else 685 status = do_vfs_lock(filp, fl); 686 return status; 687 } 688 689 static int do_setlk(struct file *filp, int cmd, struct file_lock *fl) 690 { 691 struct inode *inode = filp->f_mapping->host; 692 int status; 693 694 /* 695 * Flush all pending writes before doing anything 696 * with locks.. 697 */ 698 status = nfs_sync_mapping(filp->f_mapping); 699 if (status != 0) 700 goto out; 701 702 /* Use local locking if mounted with "-onolock" */ 703 if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) 704 status = NFS_PROTO(inode)->lock(filp, cmd, fl); 705 else 706 status = do_vfs_lock(filp, fl); 707 if (status < 0) 708 goto out; 709 /* 710 * Make sure we clear the cache whenever we try to get the lock. 711 * This makes locking act as a cache coherency point. 712 */ 713 nfs_sync_mapping(filp->f_mapping); 714 if (!nfs_have_delegation(inode, FMODE_READ)) 715 nfs_zap_caches(inode); 716 out: 717 return status; 718 } 719 720 /* 721 * Lock a (portion of) a file 722 */ 723 static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl) 724 { 725 struct inode *inode = filp->f_mapping->host; 726 int ret = -ENOLCK; 727 728 dprintk("NFS: lock(%s/%s, t=%x, fl=%x, r=%lld:%lld)\n", 729 filp->f_path.dentry->d_parent->d_name.name, 730 filp->f_path.dentry->d_name.name, 731 fl->fl_type, fl->fl_flags, 732 (long long)fl->fl_start, (long long)fl->fl_end); 733 734 nfs_inc_stats(inode, NFSIOS_VFSLOCK); 735 736 /* No mandatory locks over NFS */ 737 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) 738 goto out_err; 739 740 if (NFS_PROTO(inode)->lock_check_bounds != NULL) { 741 ret = NFS_PROTO(inode)->lock_check_bounds(fl); 742 if (ret < 0) 743 goto out_err; 744 } 745 746 if (IS_GETLK(cmd)) 747 ret = do_getlk(filp, cmd, fl); 748 else if (fl->fl_type == F_UNLCK) 749 ret = do_unlk(filp, cmd, fl); 750 else 751 ret = do_setlk(filp, cmd, fl); 752 out_err: 753 return ret; 754 } 755 756 /* 757 * Lock a (portion of) a file 758 */ 759 static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl) 760 { 761 dprintk("NFS: flock(%s/%s, t=%x, fl=%x)\n", 762 filp->f_path.dentry->d_parent->d_name.name, 763 filp->f_path.dentry->d_name.name, 764 fl->fl_type, fl->fl_flags); 765 766 if (!(fl->fl_flags & FL_FLOCK)) 767 return -ENOLCK; 768 769 /* We're simulating flock() locks using posix locks on the server */ 770 fl->fl_owner = (fl_owner_t)filp; 771 fl->fl_start = 0; 772 fl->fl_end = OFFSET_MAX; 773 774 if (fl->fl_type == F_UNLCK) 775 return do_unlk(filp, cmd, fl); 776 return do_setlk(filp, cmd, fl); 777 } 778 779 /* 780 * There is no protocol support for leases, so we have no way to implement 781 * them correctly in the face of opens by other clients. 782 */ 783 static int nfs_setlease(struct file *file, long arg, struct file_lock **fl) 784 { 785 dprintk("NFS: setlease(%s/%s, arg=%ld)\n", 786 file->f_path.dentry->d_parent->d_name.name, 787 file->f_path.dentry->d_name.name, arg); 788 789 return -EINVAL; 790 } 791