fs/nfs/file.c

   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/smp_lock.h>
  30 #include <linux/aio.h>
  31
  32 #include <asm/uaccess.h>
  33 #include <asm/system.h>
  34
  35 #include "delegation.h"
  36 #include "internal.h"
  37 #include "iostat.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_write(struct kiocb *, const struct iovec *iov,
  51                                 unsigned long nr_segs, loff_t pos);
  52 static int  nfs_file_flush(struct file *, fl_owner_t id);
  53 static int  nfs_file_fsync(struct file *, struct dentry *dentry, int datasync);
  54 static int nfs_check_flags(int flags);
  55 static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl);
  56 static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl);
  57 static int nfs_setlease(struct file *file, long arg, struct file_lock **fl);
  58
  59 static struct vm_operations_struct nfs_file_vm_ops;
  60
  61 const struct file_operations nfs_file_operations = {
  62         .llseek         = nfs_file_llseek,
  63         .read           = do_sync_read,
  64         .write          = do_sync_write,
  65         .aio_read       = nfs_file_read,
  66         .aio_write      = nfs_file_write,
  67 #ifdef CONFIG_MMU
  68         .mmap           = nfs_file_mmap,
  69 #else
  70         .mmap           = generic_file_mmap,
  71 #endif
  72         .open           = nfs_file_open,
  73         .flush          = nfs_file_flush,
  74         .release        = nfs_file_release,
  75         .fsync          = nfs_file_fsync,
  76         .lock           = nfs_lock,
  77         .flock          = nfs_flock,
  78         .splice_read    = nfs_file_splice_read,
  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         /* Ensure that dirty pages are flushed out with the right creds */
 145         if (filp->f_mode & FMODE_WRITE)
 146                 nfs_wb_all(dentry->d_inode);
 147         nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
 148         return nfs_release(inode, filp);
 149 }
 150
 151 /**
 152  * nfs_revalidate_size - Revalidate the file size
 153  * @inode - pointer to inode struct
 154  * @file - pointer to struct file
 155  *
 156  * Revalidates the file length. This is basically a wrapper around
 157  * nfs_revalidate_inode() that takes into account the fact that we may
 158  * have cached writes (in which case we don't care about the server's
 159  * idea of what the file length is), or O_DIRECT (in which case we
 160  * shouldn't trust the cache).
 161  */
 162 static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
 163 {
 164         struct nfs_server *server = NFS_SERVER(inode);
 165         struct nfs_inode *nfsi = NFS_I(inode);
 166
 167         if (server->flags & NFS_MOUNT_NOAC)
 168                 goto force_reval;
 169         if (filp->f_flags & O_DIRECT)
 170                 goto force_reval;
 171         if (nfsi->npages != 0)
 172                 return 0;
 173         if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode))
 174                 return 0;
 175 force_reval:
 176         return __nfs_revalidate_inode(server, inode);
 177 }
 178
 179 static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
 180 {
 181         loff_t loff;
 182
 183         dprintk("NFS: llseek file(%s/%s, %lld, %d)\n",
 184                         filp->f_path.dentry->d_parent->d_name.name,
 185                         filp->f_path.dentry->d_name.name,
 186                         offset, origin);
 187
 188         /* origin == SEEK_END => we must revalidate the cached file length */
 189         if (origin == SEEK_END) {
 190                 struct inode *inode = filp->f_mapping->host;
 191                 int retval = nfs_revalidate_file_size(inode, filp);
 192                 if (retval < 0)
 193                         return (loff_t)retval;
 194         }
 195         lock_kernel();  /* BKL needed? */
 196         loff = generic_file_llseek_unlocked(filp, offset, origin);
 197         unlock_kernel();
 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         int             status;
 236
 237         dprintk("NFS: flush(%s/%s)\n",
 238                         dentry->d_parent->d_name.name,
 239                         dentry->d_name.name);
 240
 241         if ((file->f_mode & FMODE_WRITE) == 0)
 242                 return 0;
 243         nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
 244
 245         /* Ensure that data+attribute caches are up to date after close() */
 246         status = nfs_do_fsync(ctx, inode);
 247         if (!status)
 248                 nfs_revalidate_inode(NFS_SERVER(inode), inode);
 249         return status;
 250 }
 251
 252 static ssize_t
 253 nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
 254                 unsigned long nr_segs, loff_t pos)
 255 {
 256         struct dentry * dentry = iocb->ki_filp->f_path.dentry;
 257         struct inode * inode = dentry->d_inode;
 258         ssize_t result;
 259         size_t count = iov_length(iov, nr_segs);
 260
 261         if (iocb->ki_filp->f_flags & O_DIRECT)
 262                 return nfs_file_direct_read(iocb, iov, nr_segs, pos);
 263
 264         dprintk("NFS: read(%s/%s, %lu@%lu)\n",
 265                 dentry->d_parent->d_name.name, dentry->d_name.name,
 266                 (unsigned long) count, (unsigned long) pos);
 267
 268         result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
 269         nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
 270         if (!result)
 271                 result = generic_file_aio_read(iocb, iov, nr_segs, pos);
 272         return result;
 273 }
 274
 275 static ssize_t
 276 nfs_file_splice_read(struct file *filp, loff_t *ppos,
 277                      struct pipe_inode_info *pipe, size_t count,
 278                      unsigned int flags)
 279 {
 280         struct dentry *dentry = filp->f_path.dentry;
 281         struct inode *inode = dentry->d_inode;
 282         ssize_t res;
 283
 284         dprintk("NFS: splice_read(%s/%s, %lu@%Lu)\n",
 285                 dentry->d_parent->d_name.name, dentry->d_name.name,
 286                 (unsigned long) count, (unsigned long long) *ppos);
 287
 288         res = nfs_revalidate_mapping(inode, filp->f_mapping);
 289         if (!res)
 290                 res = generic_file_splice_read(filp, ppos, pipe, count, flags);
 291         return res;
 292 }
 293
 294 static int
 295 nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
 296 {
 297         struct dentry *dentry = file->f_path.dentry;
 298         struct inode *inode = dentry->d_inode;
 299         int     status;
 300
 301         dprintk("NFS: mmap(%s/%s)\n",
 302                 dentry->d_parent->d_name.name, dentry->d_name.name);
 303
 304         status = nfs_revalidate_mapping(inode, file->f_mapping);
 305         if (!status) {
 306                 vma->vm_ops = &nfs_file_vm_ops;
 307                 vma->vm_flags |= VM_CAN_NONLINEAR;
 308                 file_accessed(file);
 309         }
 310         return status;
 311 }
 312
 313 /*
 314  * Flush any dirty pages for this process, and check for write errors.
 315  * The return status from this call provides a reliable indication of
 316  * whether any write errors occurred for this process.
 317  */
 318 static int
 319 nfs_file_fsync(struct file *file, struct dentry *dentry, int datasync)
 320 {
 321         struct nfs_open_context *ctx = nfs_file_open_context(file);
 322         struct inode *inode = dentry->d_inode;
 323
 324         dprintk("NFS: fsync file(%s/%s) datasync %d\n",
 325                         dentry->d_parent->d_name.name, dentry->d_name.name,
 326                         datasync);
 327
 328         nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
 329         return nfs_do_fsync(ctx, inode);
 330 }
 331
 332 /*
 333  * This does the "real" work of the write. We must allocate and lock the
 334  * page to be sent back to the generic routine, which then copies the
 335  * data from user space.
 336  *
 337  * If the writer ends up delaying the write, the writer needs to
 338  * increment the page use counts until he is done with the page.
 339  */
 340 static int nfs_write_begin(struct file *file, struct address_space *mapping,
 341                         loff_t pos, unsigned len, unsigned flags,
 342                         struct page **pagep, void **fsdata)
 343 {
 344         int ret;
 345         pgoff_t index;
 346         struct page *page;
 347         index = pos >> PAGE_CACHE_SHIFT;
 348
 349         dfprintk(PAGECACHE, "NFS: write_begin(%s/%s(%ld), %u@%lld)\n",
 350                 file->f_path.dentry->d_parent->d_name.name,
 351                 file->f_path.dentry->d_name.name,
 352                 mapping->host->i_ino, len, (long long) pos);
 353
 354         page = __grab_cache_page(mapping, index);
 355         if (!page)
 356                 return -ENOMEM;
 357         *pagep = page;
 358
 359         ret = nfs_flush_incompatible(file, page);
 360         if (ret) {
 361                 unlock_page(page);
 362                 page_cache_release(page);
 363         }
 364         return ret;
 365 }
 366
 367 static int nfs_write_end(struct file *file, struct address_space *mapping,
 368                         loff_t pos, unsigned len, unsigned copied,
 369                         struct page *page, void *fsdata)
 370 {
 371         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
 372         int status;
 373
 374         dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n",
 375                 file->f_path.dentry->d_parent->d_name.name,
 376                 file->f_path.dentry->d_name.name,
 377                 mapping->host->i_ino, len, (long long) pos);
 378
 379         /*
 380          * Zero any uninitialised parts of the page, and then mark the page
 381          * as up to date if it turns out that we're extending the file.
 382          */
 383         if (!PageUptodate(page)) {
 384                 unsigned pglen = nfs_page_length(page);
 385                 unsigned end = offset + len;
 386
 387                 if (pglen == 0) {
 388                         zero_user_segments(page, 0, offset,
 389                                         end, PAGE_CACHE_SIZE);
 390                         SetPageUptodate(page);
 391                 } else if (end >= pglen) {
 392                         zero_user_segment(page, end, PAGE_CACHE_SIZE);
 393                         if (offset == 0)
 394                                 SetPageUptodate(page);
 395                 } else
 396                         zero_user_segment(page, pglen, PAGE_CACHE_SIZE);
 397         }
 398
 399         status = nfs_updatepage(file, page, offset, copied);
 400
 401         unlock_page(page);
 402         page_cache_release(page);
 403
 404         if (status < 0)
 405                 return status;
 406         return copied;
 407 }
 408
 409 static void nfs_invalidate_page(struct page *page, unsigned long offset)
 410 {
 411         dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset);
 412
 413         if (offset != 0)
 414                 return;
 415         /* Cancel any unstarted writes on this page */
 416         nfs_wb_page_cancel(page->mapping->host, page);
 417 }
 418
 419 static int nfs_release_page(struct page *page, gfp_t gfp)
 420 {
 421         dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
 422
 423         /* If PagePrivate() is set, then the page is not freeable */
 424         return 0;
 425 }
 426
 427 static int nfs_launder_page(struct page *page)
 428 {
 429         struct inode *inode = page->mapping->host;
 430
 431         dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
 432                 inode->i_ino, (long long)page_offset(page));
 433
 434         return nfs_wb_page(inode, page);
 435 }
 436
 437 const struct address_space_operations nfs_file_aops = {
 438         .readpage = nfs_readpage,
 439         .readpages = nfs_readpages,
 440         .set_page_dirty = __set_page_dirty_nobuffers,
 441         .writepage = nfs_writepage,
 442         .writepages = nfs_writepages,
 443         .write_begin = nfs_write_begin,
 444         .write_end = nfs_write_end,
 445         .invalidatepage = nfs_invalidate_page,
 446         .releasepage = nfs_release_page,
 447         .direct_IO = nfs_direct_IO,
 448         .launder_page = nfs_launder_page,
 449 };
 450
 451 static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
 452 {
 453         struct file *filp = vma->vm_file;
 454         struct dentry *dentry = filp->f_path.dentry;
 455         unsigned pagelen;
 456         int ret = -EINVAL;
 457         struct address_space *mapping;
 458
 459         dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n",
 460                 dentry->d_parent->d_name.name, dentry->d_name.name,
 461                 filp->f_mapping->host->i_ino,
 462                 (long long)page_offset(page));
 463
 464         lock_page(page);
 465         mapping = page->mapping;
 466         if (mapping != dentry->d_inode->i_mapping)
 467                 goto out_unlock;
 468
 469         ret = 0;
 470         pagelen = nfs_page_length(page);
 471         if (pagelen == 0)
 472                 goto out_unlock;
 473
 474         ret = nfs_flush_incompatible(filp, page);
 475         if (ret != 0)
 476                 goto out_unlock;
 477
 478         ret = nfs_updatepage(filp, page, 0, pagelen);
 479         if (ret == 0)
 480                 ret = pagelen;
 481 out_unlock:
 482         unlock_page(page);
 483         return ret;
 484 }
 485
 486 static struct vm_operations_struct nfs_file_vm_ops = {
 487         .fault = filemap_fault,
 488         .page_mkwrite = nfs_vm_page_mkwrite,
 489 };
 490
 491 static int nfs_need_sync_write(struct file *filp, struct inode *inode)
 492 {
 493         struct nfs_open_context *ctx;
 494
 495         if (IS_SYNC(inode) || (filp->f_flags & O_SYNC))
 496                 return 1;
 497         ctx = nfs_file_open_context(filp);
 498         if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags))
 499                 return 1;
 500         return 0;
 501 }
 502
 503 static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
 504                                 unsigned long nr_segs, loff_t pos)
 505 {
 506         struct dentry * dentry = iocb->ki_filp->f_path.dentry;
 507         struct inode * inode = dentry->d_inode;
 508         ssize_t result;
 509         size_t count = iov_length(iov, nr_segs);
 510
 511         if (iocb->ki_filp->f_flags & O_DIRECT)
 512                 return nfs_file_direct_write(iocb, iov, nr_segs, pos);
 513
 514         dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
 515                 dentry->d_parent->d_name.name, dentry->d_name.name,
 516                 (unsigned long) count, (long long) pos);
 517
 518         result = -EBUSY;
 519         if (IS_SWAPFILE(inode))
 520                 goto out_swapfile;
 521         /*
 522          * O_APPEND implies that we must revalidate the file length.
 523          */
 524         if (iocb->ki_filp->f_flags & O_APPEND) {
 525                 result = nfs_revalidate_file_size(inode, iocb->ki_filp);
 526                 if (result)
 527                         goto out;
 528         }
 529
 530         result = count;
 531         if (!count)
 532                 goto out;
 533
 534         nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
 535         result = generic_file_aio_write(iocb, iov, nr_segs, pos);
 536         /* Return error values for O_SYNC and IS_SYNC() */
 537         if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) {
 538                 int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode);
 539                 if (err < 0)
 540                         result = err;
 541         }
 542 out:
 543         return result;
 544
 545 out_swapfile:
 546         printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
 547         goto out;
 548 }
 549
 550 static int do_getlk(struct file *filp, int cmd, struct file_lock *fl)
 551 {
 552         struct inode *inode = filp->f_mapping->host;
 553         int status = 0;
 554
 555         lock_kernel();
 556         /* Try local locking first */
 557         posix_test_lock(filp, fl);
 558         if (fl->fl_type != F_UNLCK) {
 559                 /* found a conflict */
 560                 goto out;
 561         }
 562
 563         if (nfs_have_delegation(inode, FMODE_READ))
 564                 goto out_noconflict;
 565
 566         if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)
 567                 goto out_noconflict;
 568
 569         status = NFS_PROTO(inode)->lock(filp, cmd, fl);
 570 out:
 571         unlock_kernel();
 572         return status;
 573 out_noconflict:
 574         fl->fl_type = F_UNLCK;
 575         goto out;
 576 }
 577
 578 static int do_vfs_lock(struct file *file, struct file_lock *fl)
 579 {
 580         int res = 0;
 581         switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
 582                 case FL_POSIX:
 583                         res = posix_lock_file_wait(file, fl);
 584                         break;
 585                 case FL_FLOCK:
 586                         res = flock_lock_file_wait(file, fl);
 587                         break;
 588                 default:
 589                         BUG();
 590         }
 591         if (res < 0)
 592                 dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager"
 593                         " - error %d!\n",
 594                                 __func__, res);
 595         return res;
 596 }
 597
 598 static int do_unlk(struct file *filp, int cmd, struct file_lock *fl)
 599 {
 600         struct inode *inode = filp->f_mapping->host;
 601         int status;
 602
 603         /*
 604          * Flush all pending writes before doing anything
 605          * with locks..
 606          */
 607         nfs_sync_mapping(filp->f_mapping);
 608
 609         /* NOTE: special case
 610          *      If we're signalled while cleaning up locks on process exit, we
 611          *      still need to complete the unlock.
 612          */
 613         lock_kernel();
 614         /* Use local locking if mounted with "-onolock" */
 615         if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
 616                 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
 617         else
 618                 status = do_vfs_lock(filp, fl);
 619         unlock_kernel();
 620         return status;
 621 }
 622
 623 static int do_setlk(struct file *filp, int cmd, struct file_lock *fl)
 624 {
 625         struct inode *inode = filp->f_mapping->host;
 626         int status;
 627
 628         /*
 629          * Flush all pending writes before doing anything
 630          * with locks..
 631          */
 632         status = nfs_sync_mapping(filp->f_mapping);
 633         if (status != 0)
 634                 goto out;
 635
 636         lock_kernel();
 637         /* Use local locking if mounted with "-onolock" */
 638         if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
 639                 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
 640         else
 641                 status = do_vfs_lock(filp, fl);
 642         unlock_kernel();
 643         if (status < 0)
 644                 goto out;
 645         /*
 646          * Make sure we clear the cache whenever we try to get the lock.
 647          * This makes locking act as a cache coherency point.
 648          */
 649         nfs_sync_mapping(filp->f_mapping);
 650         if (!nfs_have_delegation(inode, FMODE_READ))
 651                 nfs_zap_caches(inode);
 652 out:
 653         return status;
 654 }
 655
 656 /*
 657  * Lock a (portion of) a file
 658  */
 659 static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
 660 {
 661         struct inode *inode = filp->f_mapping->host;
 662         int ret = -ENOLCK;
 663
 664         dprintk("NFS: lock(%s/%s, t=%x, fl=%x, r=%lld:%lld)\n",
 665                         filp->f_path.dentry->d_parent->d_name.name,
 666                         filp->f_path.dentry->d_name.name,
 667                         fl->fl_type, fl->fl_flags,
 668                         (long long)fl->fl_start, (long long)fl->fl_end);
 669
 670         nfs_inc_stats(inode, NFSIOS_VFSLOCK);
 671
 672         /* No mandatory locks over NFS */
 673         if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
 674                 goto out_err;
 675
 676         if (NFS_PROTO(inode)->lock_check_bounds != NULL) {
 677                 ret = NFS_PROTO(inode)->lock_check_bounds(fl);
 678                 if (ret < 0)
 679                         goto out_err;
 680         }
 681
 682         if (IS_GETLK(cmd))
 683                 ret = do_getlk(filp, cmd, fl);
 684         else if (fl->fl_type == F_UNLCK)
 685                 ret = do_unlk(filp, cmd, fl);
 686         else
 687                 ret = do_setlk(filp, cmd, fl);
 688 out_err:
 689         return ret;
 690 }
 691
 692 /*
 693  * Lock a (portion of) a file
 694  */
 695 static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
 696 {
 697         dprintk("NFS: flock(%s/%s, t=%x, fl=%x)\n",
 698                         filp->f_path.dentry->d_parent->d_name.name,
 699                         filp->f_path.dentry->d_name.name,
 700                         fl->fl_type, fl->fl_flags);
 701
 702         /*
 703          * No BSD flocks over NFS allowed.
 704          * Note: we could try to fake a POSIX lock request here by
 705          * using ((u32) filp | 0x80000000) or some such as the pid.
 706          * Not sure whether that would be unique, though, or whether
 707          * that would break in other places.
 708          */
 709         if (!(fl->fl_flags & FL_FLOCK))
 710                 return -ENOLCK;
 711
 712         /* We're simulating flock() locks using posix locks on the server */
 713         fl->fl_owner = (fl_owner_t)filp;
 714         fl->fl_start = 0;
 715         fl->fl_end = OFFSET_MAX;
 716
 717         if (fl->fl_type == F_UNLCK)
 718                 return do_unlk(filp, cmd, fl);
 719         return do_setlk(filp, cmd, fl);
 720 }
 721
 722 /*
 723  * There is no protocol support for leases, so we have no way to implement
 724  * them correctly in the face of opens by other clients.
 725  */
 726 static int nfs_setlease(struct file *file, long arg, struct file_lock **fl)
 727 {
 728         dprintk("NFS: setlease(%s/%s, arg=%ld)\n",
 729                         file->f_path.dentry->d_parent->d_name.name,
 730                         file->f_path.dentry->d_name.name, arg);
 731
 732         return -EINVAL;
 733 }