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
 192                 int retval = nfs_revalidate_file_size(inode, filp);
 193                 if (retval < 0)
 194                         return (loff_t)retval;
 195
 196                 spin_lock(&inode->i_lock);
 197                 loff = generic_file_llseek_unlocked(filp, offset, origin);
 198                 spin_unlock(&inode->i_lock);
 199         } else
 200                 loff = generic_file_llseek_unlocked(filp, offset, origin);
 201         return loff;
 202 }
 203
 204 /*
 205  * Helper for nfs_file_flush() and nfs_file_fsync()
 206  *
 207  * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
 208  * disk, but it retrieves and clears ctx->error after synching, despite
 209  * the two being set at the same time in nfs_context_set_write_error().
 210  * This is because the former is used to notify the _next_ call to
 211  * nfs_file_write() that a write error occured, and hence cause it to
 212  * fall back to doing a synchronous write.
 213  */
 214 static int nfs_do_fsync(struct nfs_open_context *ctx, struct inode *inode)
 215 {
 216         int have_error, status;
 217         int ret = 0;
 218
 219         have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
 220         status = nfs_wb_all(inode);
 221         have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
 222         if (have_error)
 223                 ret = xchg(&ctx->error, 0);
 224         if (!ret)
 225                 ret = status;
 226         return ret;
 227 }
 228
 229 /*
 230  * Flush all dirty pages, and check for write errors.
 231  */
 232 static int
 233 nfs_file_flush(struct file *file, fl_owner_t id)
 234 {
 235         struct nfs_open_context *ctx = nfs_file_open_context(file);
 236         struct dentry   *dentry = file->f_path.dentry;
 237         struct inode    *inode = dentry->d_inode;
 238         int             status;
 239
 240         dprintk("NFS: flush(%s/%s)\n",
 241                         dentry->d_parent->d_name.name,
 242                         dentry->d_name.name);
 243
 244         if ((file->f_mode & FMODE_WRITE) == 0)
 245                 return 0;
 246         nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
 247
 248         /* Ensure that data+attribute caches are up to date after close() */
 249         status = nfs_do_fsync(ctx, inode);
 250         if (!status)
 251                 nfs_revalidate_inode(NFS_SERVER(inode), inode);
 252         return status;
 253 }
 254
 255 static ssize_t
 256 nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
 257                 unsigned long nr_segs, loff_t pos)
 258 {
 259         struct dentry * dentry = iocb->ki_filp->f_path.dentry;
 260         struct inode * inode = dentry->d_inode;
 261         ssize_t result;
 262         size_t count = iov_length(iov, nr_segs);
 263
 264         if (iocb->ki_filp->f_flags & O_DIRECT)
 265                 return nfs_file_direct_read(iocb, iov, nr_segs, pos);
 266
 267         dprintk("NFS: read(%s/%s, %lu@%lu)\n",
 268                 dentry->d_parent->d_name.name, dentry->d_name.name,
 269                 (unsigned long) count, (unsigned long) pos);
 270
 271         result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
 272         nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
 273         if (!result)
 274                 result = generic_file_aio_read(iocb, iov, nr_segs, pos);
 275         return result;
 276 }
 277
 278 static ssize_t
 279 nfs_file_splice_read(struct file *filp, loff_t *ppos,
 280                      struct pipe_inode_info *pipe, size_t count,
 281                      unsigned int flags)
 282 {
 283         struct dentry *dentry = filp->f_path.dentry;
 284         struct inode *inode = dentry->d_inode;
 285         ssize_t res;
 286
 287         dprintk("NFS: splice_read(%s/%s, %lu@%Lu)\n",
 288                 dentry->d_parent->d_name.name, dentry->d_name.name,
 289                 (unsigned long) count, (unsigned long long) *ppos);
 290
 291         res = nfs_revalidate_mapping(inode, filp->f_mapping);
 292         if (!res)
 293                 res = generic_file_splice_read(filp, ppos, pipe, count, flags);
 294         return res;
 295 }
 296
 297 static int
 298 nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
 299 {
 300         struct dentry *dentry = file->f_path.dentry;
 301         struct inode *inode = dentry->d_inode;
 302         int     status;
 303
 304         dprintk("NFS: mmap(%s/%s)\n",
 305                 dentry->d_parent->d_name.name, dentry->d_name.name);
 306
 307         status = nfs_revalidate_mapping(inode, file->f_mapping);
 308         if (!status) {
 309                 vma->vm_ops = &nfs_file_vm_ops;
 310                 vma->vm_flags |= VM_CAN_NONLINEAR;
 311                 file_accessed(file);
 312         }
 313         return status;
 314 }
 315
 316 /*
 317  * Flush any dirty pages for this process, and check for write errors.
 318  * The return status from this call provides a reliable indication of
 319  * whether any write errors occurred for this process.
 320  */
 321 static int
 322 nfs_file_fsync(struct file *file, struct dentry *dentry, int datasync)
 323 {
 324         struct nfs_open_context *ctx = nfs_file_open_context(file);
 325         struct inode *inode = dentry->d_inode;
 326
 327         dprintk("NFS: fsync file(%s/%s) datasync %d\n",
 328                         dentry->d_parent->d_name.name, dentry->d_name.name,
 329                         datasync);
 330
 331         nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
 332         return nfs_do_fsync(ctx, inode);
 333 }
 334
 335 /*
 336  * This does the "real" work of the write. We must allocate and lock the
 337  * page to be sent back to the generic routine, which then copies the
 338  * data from user space.
 339  *
 340  * If the writer ends up delaying the write, the writer needs to
 341  * increment the page use counts until he is done with the page.
 342  */
 343 static int nfs_write_begin(struct file *file, struct address_space *mapping,
 344                         loff_t pos, unsigned len, unsigned flags,
 345                         struct page **pagep, void **fsdata)
 346 {
 347         int ret;
 348         pgoff_t index;
 349         struct page *page;
 350         index = pos >> PAGE_CACHE_SHIFT;
 351
 352         dfprintk(PAGECACHE, "NFS: write_begin(%s/%s(%ld), %u@%lld)\n",
 353                 file->f_path.dentry->d_parent->d_name.name,
 354                 file->f_path.dentry->d_name.name,
 355                 mapping->host->i_ino, len, (long long) pos);
 356
 357         page = grab_cache_page_write_begin(mapping, index, flags);
 358         if (!page)
 359                 return -ENOMEM;
 360         *pagep = page;
 361
 362         ret = nfs_flush_incompatible(file, page);
 363         if (ret) {
 364                 unlock_page(page);
 365                 page_cache_release(page);
 366         }
 367         return ret;
 368 }
 369
 370 static int nfs_write_end(struct file *file, struct address_space *mapping,
 371                         loff_t pos, unsigned len, unsigned copied,
 372                         struct page *page, void *fsdata)
 373 {
 374         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
 375         int status;
 376
 377         dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n",
 378                 file->f_path.dentry->d_parent->d_name.name,
 379                 file->f_path.dentry->d_name.name,
 380                 mapping->host->i_ino, len, (long long) pos);
 381
 382         /*
 383          * Zero any uninitialised parts of the page, and then mark the page
 384          * as up to date if it turns out that we're extending the file.
 385          */
 386         if (!PageUptodate(page)) {
 387                 unsigned pglen = nfs_page_length(page);
 388                 unsigned end = offset + len;
 389
 390                 if (pglen == 0) {
 391                         zero_user_segments(page, 0, offset,
 392                                         end, PAGE_CACHE_SIZE);
 393                         SetPageUptodate(page);
 394                 } else if (end >= pglen) {
 395                         zero_user_segment(page, end, PAGE_CACHE_SIZE);
 396                         if (offset == 0)
 397                                 SetPageUptodate(page);
 398                 } else
 399                         zero_user_segment(page, pglen, PAGE_CACHE_SIZE);
 400         }
 401
 402         status = nfs_updatepage(file, page, offset, copied);
 403
 404         unlock_page(page);
 405         page_cache_release(page);
 406
 407         if (status < 0)
 408                 return status;
 409         return copied;
 410 }
 411
 412 static void nfs_invalidate_page(struct page *page, unsigned long offset)
 413 {
 414         dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset);
 415
 416         if (offset != 0)
 417                 return;
 418         /* Cancel any unstarted writes on this page */
 419         nfs_wb_page_cancel(page->mapping->host, page);
 420 }
 421
 422 static int nfs_release_page(struct page *page, gfp_t gfp)
 423 {
 424         dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
 425
 426         /* If PagePrivate() is set, then the page is not freeable */
 427         return 0;
 428 }
 429
 430 static int nfs_launder_page(struct page *page)
 431 {
 432         struct inode *inode = page->mapping->host;
 433
 434         dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
 435                 inode->i_ino, (long long)page_offset(page));
 436
 437         return nfs_wb_page(inode, page);
 438 }
 439
 440 const struct address_space_operations nfs_file_aops = {
 441         .readpage = nfs_readpage,
 442         .readpages = nfs_readpages,
 443         .set_page_dirty = __set_page_dirty_nobuffers,
 444         .writepage = nfs_writepage,
 445         .writepages = nfs_writepages,
 446         .write_begin = nfs_write_begin,
 447         .write_end = nfs_write_end,
 448         .invalidatepage = nfs_invalidate_page,
 449         .releasepage = nfs_release_page,
 450         .direct_IO = nfs_direct_IO,
 451         .launder_page = nfs_launder_page,
 452 };
 453
 454 static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
 455 {
 456         struct file *filp = vma->vm_file;
 457         struct dentry *dentry = filp->f_path.dentry;
 458         unsigned pagelen;
 459         int ret = -EINVAL;
 460         struct address_space *mapping;
 461
 462         dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n",
 463                 dentry->d_parent->d_name.name, dentry->d_name.name,
 464                 filp->f_mapping->host->i_ino,
 465                 (long long)page_offset(page));
 466
 467         lock_page(page);
 468         mapping = page->mapping;
 469         if (mapping != dentry->d_inode->i_mapping)
 470                 goto out_unlock;
 471
 472         ret = 0;
 473         pagelen = nfs_page_length(page);
 474         if (pagelen == 0)
 475                 goto out_unlock;
 476
 477         ret = nfs_flush_incompatible(filp, page);
 478         if (ret != 0)
 479                 goto out_unlock;
 480
 481         ret = nfs_updatepage(filp, page, 0, pagelen);
 482         if (ret == 0)
 483                 ret = pagelen;
 484 out_unlock:
 485         unlock_page(page);
 486         return ret;
 487 }
 488
 489 static struct vm_operations_struct nfs_file_vm_ops = {
 490         .fault = filemap_fault,
 491         .page_mkwrite = nfs_vm_page_mkwrite,
 492 };
 493
 494 static int nfs_need_sync_write(struct file *filp, struct inode *inode)
 495 {
 496         struct nfs_open_context *ctx;
 497
 498         if (IS_SYNC(inode) || (filp->f_flags & O_SYNC))
 499                 return 1;
 500         ctx = nfs_file_open_context(filp);
 501         if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags))
 502                 return 1;
 503         return 0;
 504 }
 505
 506 static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
 507                                 unsigned long nr_segs, loff_t pos)
 508 {
 509         struct dentry * dentry = iocb->ki_filp->f_path.dentry;
 510         struct inode * inode = dentry->d_inode;
 511         ssize_t result;
 512         size_t count = iov_length(iov, nr_segs);
 513
 514         if (iocb->ki_filp->f_flags & O_DIRECT)
 515                 return nfs_file_direct_write(iocb, iov, nr_segs, pos);
 516
 517         dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
 518                 dentry->d_parent->d_name.name, dentry->d_name.name,
 519                 (unsigned long) count, (long long) pos);
 520
 521         result = -EBUSY;
 522         if (IS_SWAPFILE(inode))
 523                 goto out_swapfile;
 524         /*
 525          * O_APPEND implies that we must revalidate the file length.
 526          */
 527         if (iocb->ki_filp->f_flags & O_APPEND) {
 528                 result = nfs_revalidate_file_size(inode, iocb->ki_filp);
 529                 if (result)
 530                         goto out;
 531         }
 532
 533         result = count;
 534         if (!count)
 535                 goto out;
 536
 537         nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
 538         result = generic_file_aio_write(iocb, iov, nr_segs, pos);
 539         /* Return error values for O_SYNC and IS_SYNC() */
 540         if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) {
 541                 int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode);
 542                 if (err < 0)
 543                         result = err;
 544         }
 545 out:
 546         return result;
 547
 548 out_swapfile:
 549         printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
 550         goto out;
 551 }
 552
 553 static int do_getlk(struct file *filp, int cmd, struct file_lock *fl)
 554 {
 555         struct inode *inode = filp->f_mapping->host;
 556         int status = 0;
 557
 558         lock_kernel();
 559         /* Try local locking first */
 560         posix_test_lock(filp, fl);
 561         if (fl->fl_type != F_UNLCK) {
 562                 /* found a conflict */
 563                 goto out;
 564         }
 565
 566         if (nfs_have_delegation(inode, FMODE_READ))
 567                 goto out_noconflict;
 568
 569         if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)
 570                 goto out_noconflict;
 571
 572         status = NFS_PROTO(inode)->lock(filp, cmd, fl);
 573 out:
 574         unlock_kernel();
 575         return status;
 576 out_noconflict:
 577         fl->fl_type = F_UNLCK;
 578         goto out;
 579 }
 580
 581 static int do_vfs_lock(struct file *file, struct file_lock *fl)
 582 {
 583         int res = 0;
 584         switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
 585                 case FL_POSIX:
 586                         res = posix_lock_file_wait(file, fl);
 587                         break;
 588                 case FL_FLOCK:
 589                         res = flock_lock_file_wait(file, fl);
 590                         break;
 591                 default:
 592                         BUG();
 593         }
 594         if (res < 0)
 595                 dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager"
 596                         " - error %d!\n",
 597                                 __func__, res);
 598         return res;
 599 }
 600
 601 static int do_unlk(struct file *filp, int cmd, struct file_lock *fl)
 602 {
 603         struct inode *inode = filp->f_mapping->host;
 604         int status;
 605
 606         /*
 607          * Flush all pending writes before doing anything
 608          * with locks..
 609          */
 610         nfs_sync_mapping(filp->f_mapping);
 611
 612         /* NOTE: special case
 613          *      If we're signalled while cleaning up locks on process exit, we
 614          *      still need to complete the unlock.
 615          */
 616         lock_kernel();
 617         /* Use local locking if mounted with "-onolock" */
 618         if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
 619                 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
 620         else
 621                 status = do_vfs_lock(filp, fl);
 622         unlock_kernel();
 623         return status;
 624 }
 625
 626 static int do_setlk(struct file *filp, int cmd, struct file_lock *fl)
 627 {
 628         struct inode *inode = filp->f_mapping->host;
 629         int status;
 630
 631         /*
 632          * Flush all pending writes before doing anything
 633          * with locks..
 634          */
 635         status = nfs_sync_mapping(filp->f_mapping);
 636         if (status != 0)
 637                 goto out;
 638
 639         lock_kernel();
 640         /* Use local locking if mounted with "-onolock" */
 641         if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
 642                 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
 643         else
 644                 status = do_vfs_lock(filp, fl);
 645         unlock_kernel();
 646         if (status < 0)
 647                 goto out;
 648         /*
 649          * Make sure we clear the cache whenever we try to get the lock.
 650          * This makes locking act as a cache coherency point.
 651          */
 652         nfs_sync_mapping(filp->f_mapping);
 653         if (!nfs_have_delegation(inode, FMODE_READ))
 654                 nfs_zap_caches(inode);
 655 out:
 656         return status;
 657 }
 658
 659 /*
 660  * Lock a (portion of) a file
 661  */
 662 static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
 663 {
 664         struct inode *inode = filp->f_mapping->host;
 665         int ret = -ENOLCK;
 666
 667         dprintk("NFS: lock(%s/%s, t=%x, fl=%x, r=%lld:%lld)\n",
 668                         filp->f_path.dentry->d_parent->d_name.name,
 669                         filp->f_path.dentry->d_name.name,
 670                         fl->fl_type, fl->fl_flags,
 671                         (long long)fl->fl_start, (long long)fl->fl_end);
 672
 673         nfs_inc_stats(inode, NFSIOS_VFSLOCK);
 674
 675         /* No mandatory locks over NFS */
 676         if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
 677                 goto out_err;
 678
 679         if (NFS_PROTO(inode)->lock_check_bounds != NULL) {
 680                 ret = NFS_PROTO(inode)->lock_check_bounds(fl);
 681                 if (ret < 0)
 682                         goto out_err;
 683         }
 684
 685         if (IS_GETLK(cmd))
 686                 ret = do_getlk(filp, cmd, fl);
 687         else if (fl->fl_type == F_UNLCK)
 688                 ret = do_unlk(filp, cmd, fl);
 689         else
 690                 ret = do_setlk(filp, cmd, fl);
 691 out_err:
 692         return ret;
 693 }
 694
 695 /*
 696  * Lock a (portion of) a file
 697  */
 698 static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
 699 {
 700         dprintk("NFS: flock(%s/%s, t=%x, fl=%x)\n",
 701                         filp->f_path.dentry->d_parent->d_name.name,
 702                         filp->f_path.dentry->d_name.name,
 703                         fl->fl_type, fl->fl_flags);
 704
 705         if (!(fl->fl_flags & FL_FLOCK))
 706                 return -ENOLCK;
 707
 708         /* We're simulating flock() locks using posix locks on the server */
 709         fl->fl_owner = (fl_owner_t)filp;
 710         fl->fl_start = 0;
 711         fl->fl_end = OFFSET_MAX;
 712
 713         if (fl->fl_type == F_UNLCK)
 714                 return do_unlk(filp, cmd, fl);
 715         return do_setlk(filp, cmd, fl);
 716 }
 717
 718 /*
 719  * There is no protocol support for leases, so we have no way to implement
 720  * them correctly in the face of opens by other clients.
 721  */
 722 static int nfs_setlease(struct file *file, long arg, struct file_lock **fl)
 723 {
 724         dprintk("NFS: setlease(%s/%s, arg=%ld)\n",
 725                         file->f_path.dentry->d_parent->d_name.name,
 726                         file->f_path.dentry->d_name.name, arg);
 727
 728         return -EINVAL;
 729 }