4 * Copyright (C) 1992 Rick Sladkey
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.
12 * Expire cache on write to a file by Wai S Kok (Oct 1994).
14 * Total rewrite of read side for new NFS buffer cache.. Linus.
16 * nfs regular file handling functions
19 #include <linux/module.h>
20 #include <linux/time.h>
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/fcntl.h>
24 #include <linux/stat.h>
25 #include <linux/nfs_fs.h>
26 #include <linux/nfs_mount.h>
28 #include <linux/pagemap.h>
29 #include <linux/gfp.h>
30 #include <linux/swap.h>
32 #include <asm/uaccess.h>
34 #include "delegation.h"
42 #define NFSDBG_FACILITY NFSDBG_FILE
44 static const struct vm_operations_struct nfs_file_vm_ops
;
46 /* Hack for future NFS swap support */
48 # define IS_SWAPFILE(inode) (0)
51 int nfs_check_flags(int flags
)
53 if ((flags
& (O_APPEND
| O_DIRECT
)) == (O_APPEND
| O_DIRECT
))
58 EXPORT_SYMBOL_GPL(nfs_check_flags
);
64 nfs_file_open(struct inode
*inode
, struct file
*filp
)
68 dprintk("NFS: open file(%pD2)\n", filp
);
70 nfs_inc_stats(inode
, NFSIOS_VFSOPEN
);
71 res
= nfs_check_flags(filp
->f_flags
);
75 res
= nfs_open(inode
, filp
);
80 nfs_file_release(struct inode
*inode
, struct file
*filp
)
82 dprintk("NFS: release(%pD2)\n", filp
);
84 nfs_inc_stats(inode
, NFSIOS_VFSRELEASE
);
85 return nfs_release(inode
, filp
);
87 EXPORT_SYMBOL_GPL(nfs_file_release
);
90 * nfs_revalidate_size - Revalidate the file size
91 * @inode - pointer to inode struct
92 * @file - pointer to struct file
94 * Revalidates the file length. This is basically a wrapper around
95 * nfs_revalidate_inode() that takes into account the fact that we may
96 * have cached writes (in which case we don't care about the server's
97 * idea of what the file length is), or O_DIRECT (in which case we
98 * shouldn't trust the cache).
100 static int nfs_revalidate_file_size(struct inode
*inode
, struct file
*filp
)
102 struct nfs_server
*server
= NFS_SERVER(inode
);
103 struct nfs_inode
*nfsi
= NFS_I(inode
);
105 if (nfs_have_delegated_attributes(inode
))
108 if (filp
->f_flags
& O_DIRECT
)
110 if (nfsi
->cache_validity
& NFS_INO_REVAL_PAGECACHE
)
112 if (nfs_attribute_timeout(inode
))
117 return __nfs_revalidate_inode(server
, inode
);
120 loff_t
nfs_file_llseek(struct file
*filp
, loff_t offset
, int whence
)
122 dprintk("NFS: llseek file(%pD2, %lld, %d)\n",
123 filp
, offset
, whence
);
126 * whence == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate
127 * the cached file length
129 if (whence
!= SEEK_SET
&& whence
!= SEEK_CUR
) {
130 struct inode
*inode
= filp
->f_mapping
->host
;
132 int retval
= nfs_revalidate_file_size(inode
, filp
);
134 return (loff_t
)retval
;
137 return generic_file_llseek(filp
, offset
, whence
);
139 EXPORT_SYMBOL_GPL(nfs_file_llseek
);
142 * Flush all dirty pages, and check for write errors.
145 nfs_file_flush(struct file
*file
, fl_owner_t id
)
147 struct inode
*inode
= file_inode(file
);
149 dprintk("NFS: flush(%pD2)\n", file
);
151 nfs_inc_stats(inode
, NFSIOS_VFSFLUSH
);
152 if ((file
->f_mode
& FMODE_WRITE
) == 0)
156 * If we're holding a write delegation, then just start the i/o
157 * but don't wait for completion (or send a commit).
159 if (NFS_PROTO(inode
)->have_delegation(inode
, FMODE_WRITE
))
160 return filemap_fdatawrite(file
->f_mapping
);
162 /* Flush writes to the server and return any errors */
163 return vfs_fsync(file
, 0);
165 EXPORT_SYMBOL_GPL(nfs_file_flush
);
168 nfs_file_read(struct kiocb
*iocb
, struct iov_iter
*to
)
170 struct inode
*inode
= file_inode(iocb
->ki_filp
);
173 if (iocb
->ki_flags
& IOCB_DIRECT
)
174 return nfs_file_direct_read(iocb
, to
, iocb
->ki_pos
);
176 dprintk("NFS: read(%pD2, %zu@%lu)\n",
178 iov_iter_count(to
), (unsigned long) iocb
->ki_pos
);
180 result
= nfs_revalidate_mapping_protected(inode
, iocb
->ki_filp
->f_mapping
);
182 result
= generic_file_read_iter(iocb
, to
);
184 nfs_add_stats(inode
, NFSIOS_NORMALREADBYTES
, result
);
188 EXPORT_SYMBOL_GPL(nfs_file_read
);
191 nfs_file_splice_read(struct file
*filp
, loff_t
*ppos
,
192 struct pipe_inode_info
*pipe
, size_t count
,
195 struct inode
*inode
= file_inode(filp
);
198 dprintk("NFS: splice_read(%pD2, %lu@%Lu)\n",
199 filp
, (unsigned long) count
, (unsigned long long) *ppos
);
201 res
= nfs_revalidate_mapping_protected(inode
, filp
->f_mapping
);
203 res
= generic_file_splice_read(filp
, ppos
, pipe
, count
, flags
);
205 nfs_add_stats(inode
, NFSIOS_NORMALREADBYTES
, res
);
209 EXPORT_SYMBOL_GPL(nfs_file_splice_read
);
212 nfs_file_mmap(struct file
* file
, struct vm_area_struct
* vma
)
214 struct inode
*inode
= file_inode(file
);
217 dprintk("NFS: mmap(%pD2)\n", file
);
219 /* Note: generic_file_mmap() returns ENOSYS on nommu systems
220 * so we call that before revalidating the mapping
222 status
= generic_file_mmap(file
, vma
);
224 vma
->vm_ops
= &nfs_file_vm_ops
;
225 status
= nfs_revalidate_mapping(inode
, file
->f_mapping
);
229 EXPORT_SYMBOL_GPL(nfs_file_mmap
);
232 * Flush any dirty pages for this process, and check for write errors.
233 * The return status from this call provides a reliable indication of
234 * whether any write errors occurred for this process.
236 * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
237 * disk, but it retrieves and clears ctx->error after synching, despite
238 * the two being set at the same time in nfs_context_set_write_error().
239 * This is because the former is used to notify the _next_ call to
240 * nfs_file_write() that a write error occurred, and hence cause it to
241 * fall back to doing a synchronous write.
244 nfs_file_fsync_commit(struct file
*file
, loff_t start
, loff_t end
, int datasync
)
246 struct nfs_open_context
*ctx
= nfs_file_open_context(file
);
247 struct inode
*inode
= file_inode(file
);
248 int have_error
, do_resend
, status
;
251 dprintk("NFS: fsync file(%pD2) datasync %d\n", file
, datasync
);
253 nfs_inc_stats(inode
, NFSIOS_VFSFSYNC
);
254 do_resend
= test_and_clear_bit(NFS_CONTEXT_RESEND_WRITES
, &ctx
->flags
);
255 have_error
= test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE
, &ctx
->flags
);
256 status
= nfs_commit_inode(inode
, FLUSH_SYNC
);
257 have_error
|= test_bit(NFS_CONTEXT_ERROR_WRITE
, &ctx
->flags
);
259 ret
= xchg(&ctx
->error
, 0);
267 do_resend
|= test_bit(NFS_CONTEXT_RESEND_WRITES
, &ctx
->flags
);
273 EXPORT_SYMBOL_GPL(nfs_file_fsync_commit
);
276 nfs_file_fsync(struct file
*file
, loff_t start
, loff_t end
, int datasync
)
279 struct inode
*inode
= file_inode(file
);
281 trace_nfs_fsync_enter(inode
);
283 nfs_inode_dio_wait(inode
);
285 ret
= filemap_write_and_wait_range(inode
->i_mapping
, start
, end
);
288 mutex_lock(&inode
->i_mutex
);
289 ret
= nfs_file_fsync_commit(file
, start
, end
, datasync
);
290 mutex_unlock(&inode
->i_mutex
);
292 * If nfs_file_fsync_commit detected a server reboot, then
293 * resend all dirty pages that might have been covered by
294 * the NFS_CONTEXT_RESEND_WRITES flag
298 } while (ret
== -EAGAIN
);
300 trace_nfs_fsync_exit(inode
, ret
);
305 * Decide whether a read/modify/write cycle may be more efficient
306 * then a modify/write/read cycle when writing to a page in the
309 * The modify/write/read cycle may occur if a page is read before
310 * being completely filled by the writer. In this situation, the
311 * page must be completely written to stable storage on the server
312 * before it can be refilled by reading in the page from the server.
313 * This can lead to expensive, small, FILE_SYNC mode writes being
316 * It may be more efficient to read the page first if the file is
317 * open for reading in addition to writing, the page is not marked
318 * as Uptodate, it is not dirty or waiting to be committed,
319 * indicating that it was previously allocated and then modified,
320 * that there were valid bytes of data in that range of the file,
321 * and that the new data won't completely replace the old data in
322 * that range of the file.
324 static int nfs_want_read_modify_write(struct file
*file
, struct page
*page
,
325 loff_t pos
, unsigned len
)
327 unsigned int pglen
= nfs_page_length(page
);
328 unsigned int offset
= pos
& (PAGE_CACHE_SIZE
- 1);
329 unsigned int end
= offset
+ len
;
331 if (pnfs_ld_read_whole_page(file
->f_mapping
->host
)) {
332 if (!PageUptodate(page
))
337 if ((file
->f_mode
& FMODE_READ
) && /* open for read? */
338 !PageUptodate(page
) && /* Uptodate? */
339 !PagePrivate(page
) && /* i/o request already? */
340 pglen
&& /* valid bytes of file? */
341 (end
< pglen
|| offset
)) /* replace all valid bytes? */
347 * This does the "real" work of the write. We must allocate and lock the
348 * page to be sent back to the generic routine, which then copies the
349 * data from user space.
351 * If the writer ends up delaying the write, the writer needs to
352 * increment the page use counts until he is done with the page.
354 static int nfs_write_begin(struct file
*file
, struct address_space
*mapping
,
355 loff_t pos
, unsigned len
, unsigned flags
,
356 struct page
**pagep
, void **fsdata
)
359 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
363 dfprintk(PAGECACHE
, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
364 file
, mapping
->host
->i_ino
, len
, (long long) pos
);
368 * Prevent starvation issues if someone is doing a consistency
371 ret
= wait_on_bit_action(&NFS_I(mapping
->host
)->flags
, NFS_INO_FLUSHING
,
372 nfs_wait_bit_killable
, TASK_KILLABLE
);
376 * Wait for O_DIRECT to complete
378 nfs_inode_dio_wait(mapping
->host
);
380 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
385 ret
= nfs_flush_incompatible(file
, page
);
388 page_cache_release(page
);
389 } else if (!once_thru
&&
390 nfs_want_read_modify_write(file
, page
, pos
, len
)) {
392 ret
= nfs_readpage(file
, page
);
393 page_cache_release(page
);
400 static int nfs_write_end(struct file
*file
, struct address_space
*mapping
,
401 loff_t pos
, unsigned len
, unsigned copied
,
402 struct page
*page
, void *fsdata
)
404 unsigned offset
= pos
& (PAGE_CACHE_SIZE
- 1);
405 struct nfs_open_context
*ctx
= nfs_file_open_context(file
);
408 dfprintk(PAGECACHE
, "NFS: write_end(%pD2(%lu), %u@%lld)\n",
409 file
, mapping
->host
->i_ino
, len
, (long long) pos
);
412 * Zero any uninitialised parts of the page, and then mark the page
413 * as up to date if it turns out that we're extending the file.
415 if (!PageUptodate(page
)) {
416 unsigned pglen
= nfs_page_length(page
);
417 unsigned end
= offset
+ len
;
420 zero_user_segments(page
, 0, offset
,
421 end
, PAGE_CACHE_SIZE
);
422 SetPageUptodate(page
);
423 } else if (end
>= pglen
) {
424 zero_user_segment(page
, end
, PAGE_CACHE_SIZE
);
426 SetPageUptodate(page
);
428 zero_user_segment(page
, pglen
, PAGE_CACHE_SIZE
);
431 status
= nfs_updatepage(file
, page
, offset
, copied
);
434 page_cache_release(page
);
438 NFS_I(mapping
->host
)->write_io
+= copied
;
440 if (nfs_ctx_key_to_expire(ctx
)) {
441 status
= nfs_wb_all(mapping
->host
);
450 * Partially or wholly invalidate a page
451 * - Release the private state associated with a page if undergoing complete
453 * - Called if either PG_private or PG_fscache is set on the page
454 * - Caller holds page lock
456 static void nfs_invalidate_page(struct page
*page
, unsigned int offset
,
459 dfprintk(PAGECACHE
, "NFS: invalidate_page(%p, %u, %u)\n",
460 page
, offset
, length
);
462 if (offset
!= 0 || length
< PAGE_CACHE_SIZE
)
464 /* Cancel any unstarted writes on this page */
465 nfs_wb_page_cancel(page_file_mapping(page
)->host
, page
);
467 nfs_fscache_invalidate_page(page
, page
->mapping
->host
);
471 * Attempt to release the private state associated with a page
472 * - Called if either PG_private or PG_fscache is set on the page
473 * - Caller holds page lock
474 * - Return true (may release page) or false (may not)
476 static int nfs_release_page(struct page
*page
, gfp_t gfp
)
478 struct address_space
*mapping
= page
->mapping
;
480 dfprintk(PAGECACHE
, "NFS: release_page(%p)\n", page
);
482 /* Always try to initiate a 'commit' if relevant, but only
483 * wait for it if __GFP_WAIT is set. Even then, only wait 1
484 * second and only if the 'bdi' is not congested.
485 * Waiting indefinitely can cause deadlocks when the NFS
486 * server is on this machine, when a new TCP connection is
487 * needed and in other rare cases. There is no particular
488 * need to wait extensively here. A short wait has the
489 * benefit that someone else can worry about the freezer.
492 struct nfs_server
*nfss
= NFS_SERVER(mapping
->host
);
493 nfs_commit_inode(mapping
->host
, 0);
494 if ((gfp
& __GFP_WAIT
) &&
495 !bdi_write_congested(&nfss
->backing_dev_info
)) {
496 wait_on_page_bit_killable_timeout(page
, PG_private
,
498 if (PagePrivate(page
))
499 set_bdi_congested(&nfss
->backing_dev_info
,
503 /* If PagePrivate() is set, then the page is not freeable */
504 if (PagePrivate(page
))
506 return nfs_fscache_release_page(page
, gfp
);
509 static void nfs_check_dirty_writeback(struct page
*page
,
510 bool *dirty
, bool *writeback
)
512 struct nfs_inode
*nfsi
;
513 struct address_space
*mapping
= page_file_mapping(page
);
515 if (!mapping
|| PageSwapCache(page
))
519 * Check if an unstable page is currently being committed and
520 * if so, have the VM treat it as if the page is under writeback
521 * so it will not block due to pages that will shortly be freeable.
523 nfsi
= NFS_I(mapping
->host
);
524 if (test_bit(NFS_INO_COMMIT
, &nfsi
->flags
)) {
530 * If PagePrivate() is set, then the page is not freeable and as the
531 * inode is not being committed, it's not going to be cleaned in the
532 * near future so treat it as dirty
534 if (PagePrivate(page
))
539 * Attempt to clear the private state associated with a page when an error
540 * occurs that requires the cached contents of an inode to be written back or
542 * - Called if either PG_private or fscache is set on the page
543 * - Caller holds page lock
544 * - Return 0 if successful, -error otherwise
546 static int nfs_launder_page(struct page
*page
)
548 struct inode
*inode
= page_file_mapping(page
)->host
;
549 struct nfs_inode
*nfsi
= NFS_I(inode
);
551 dfprintk(PAGECACHE
, "NFS: launder_page(%ld, %llu)\n",
552 inode
->i_ino
, (long long)page_offset(page
));
554 nfs_fscache_wait_on_page_write(nfsi
, page
);
555 return nfs_wb_page(inode
, page
);
558 #ifdef CONFIG_NFS_SWAP
559 static int nfs_swap_activate(struct swap_info_struct
*sis
, struct file
*file
,
563 struct rpc_clnt
*clnt
= NFS_CLIENT(file
->f_mapping
->host
);
568 ret
= xs_swapper(rcu_dereference(clnt
->cl_xprt
), 1);
574 static void nfs_swap_deactivate(struct file
*file
)
576 struct rpc_clnt
*clnt
= NFS_CLIENT(file
->f_mapping
->host
);
579 xs_swapper(rcu_dereference(clnt
->cl_xprt
), 0);
584 const struct address_space_operations nfs_file_aops
= {
585 .readpage
= nfs_readpage
,
586 .readpages
= nfs_readpages
,
587 .set_page_dirty
= __set_page_dirty_nobuffers
,
588 .writepage
= nfs_writepage
,
589 .writepages
= nfs_writepages
,
590 .write_begin
= nfs_write_begin
,
591 .write_end
= nfs_write_end
,
592 .invalidatepage
= nfs_invalidate_page
,
593 .releasepage
= nfs_release_page
,
594 .direct_IO
= nfs_direct_IO
,
595 .migratepage
= nfs_migrate_page
,
596 .launder_page
= nfs_launder_page
,
597 .is_dirty_writeback
= nfs_check_dirty_writeback
,
598 .error_remove_page
= generic_error_remove_page
,
599 #ifdef CONFIG_NFS_SWAP
600 .swap_activate
= nfs_swap_activate
,
601 .swap_deactivate
= nfs_swap_deactivate
,
606 * Notification that a PTE pointing to an NFS page is about to be made
607 * writable, implying that someone is about to modify the page through a
608 * shared-writable mapping
610 static int nfs_vm_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
612 struct page
*page
= vmf
->page
;
613 struct file
*filp
= vma
->vm_file
;
614 struct inode
*inode
= file_inode(filp
);
616 int ret
= VM_FAULT_NOPAGE
;
617 struct address_space
*mapping
;
619 dfprintk(PAGECACHE
, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
620 filp
, filp
->f_mapping
->host
->i_ino
,
621 (long long)page_offset(page
));
623 /* make sure the cache has finished storing the page */
624 nfs_fscache_wait_on_page_write(NFS_I(inode
), page
);
626 wait_on_bit_action(&NFS_I(inode
)->flags
, NFS_INO_INVALIDATING
,
627 nfs_wait_bit_killable
, TASK_KILLABLE
);
630 mapping
= page_file_mapping(page
);
631 if (mapping
!= inode
->i_mapping
)
634 wait_on_page_writeback(page
);
636 pagelen
= nfs_page_length(page
);
640 ret
= VM_FAULT_LOCKED
;
641 if (nfs_flush_incompatible(filp
, page
) == 0 &&
642 nfs_updatepage(filp
, page
, 0, pagelen
) == 0)
645 ret
= VM_FAULT_SIGBUS
;
652 static const struct vm_operations_struct nfs_file_vm_ops
= {
653 .fault
= filemap_fault
,
654 .map_pages
= filemap_map_pages
,
655 .page_mkwrite
= nfs_vm_page_mkwrite
,
658 static int nfs_need_sync_write(struct file
*filp
, struct inode
*inode
)
660 struct nfs_open_context
*ctx
;
662 if (IS_SYNC(inode
) || (filp
->f_flags
& O_DSYNC
))
664 ctx
= nfs_file_open_context(filp
);
665 if (test_bit(NFS_CONTEXT_ERROR_WRITE
, &ctx
->flags
) ||
666 nfs_ctx_key_to_expire(ctx
))
671 ssize_t
nfs_file_write(struct kiocb
*iocb
, struct iov_iter
*from
)
673 struct file
*file
= iocb
->ki_filp
;
674 struct inode
*inode
= file_inode(file
);
675 unsigned long written
= 0;
677 size_t count
= iov_iter_count(from
);
679 result
= nfs_key_timeout_notify(file
, inode
);
683 if (iocb
->ki_flags
& IOCB_DIRECT
) {
684 result
= generic_write_checks(iocb
, from
);
687 return nfs_file_direct_write(iocb
, from
);
690 dprintk("NFS: write(%pD2, %zu@%Ld)\n",
691 file
, count
, (long long) iocb
->ki_pos
);
694 if (IS_SWAPFILE(inode
))
697 * O_APPEND implies that we must revalidate the file length.
699 if (iocb
->ki_flags
& IOCB_APPEND
) {
700 result
= nfs_revalidate_file_size(inode
, file
);
709 result
= generic_file_write_iter(iocb
, from
);
713 /* Return error values for O_DSYNC and IS_SYNC() */
714 if (result
>= 0 && nfs_need_sync_write(file
, inode
)) {
715 int err
= vfs_fsync(file
, 0);
720 nfs_add_stats(inode
, NFSIOS_NORMALWRITTENBYTES
, written
);
725 printk(KERN_INFO
"NFS: attempt to write to active swap file!\n");
728 EXPORT_SYMBOL_GPL(nfs_file_write
);
731 do_getlk(struct file
*filp
, int cmd
, struct file_lock
*fl
, int is_local
)
733 struct inode
*inode
= filp
->f_mapping
->host
;
735 unsigned int saved_type
= fl
->fl_type
;
737 /* Try local locking first */
738 posix_test_lock(filp
, fl
);
739 if (fl
->fl_type
!= F_UNLCK
) {
740 /* found a conflict */
743 fl
->fl_type
= saved_type
;
745 if (NFS_PROTO(inode
)->have_delegation(inode
, FMODE_READ
))
751 status
= NFS_PROTO(inode
)->lock(filp
, cmd
, fl
);
755 fl
->fl_type
= F_UNLCK
;
759 static int do_vfs_lock(struct file
*file
, struct file_lock
*fl
)
762 switch (fl
->fl_flags
& (FL_POSIX
|FL_FLOCK
)) {
764 res
= posix_lock_file_wait(file
, fl
);
767 res
= flock_lock_file_wait(file
, fl
);
776 do_unlk(struct file
*filp
, int cmd
, struct file_lock
*fl
, int is_local
)
778 struct inode
*inode
= filp
->f_mapping
->host
;
779 struct nfs_lock_context
*l_ctx
;
783 * Flush all pending writes before doing anything
788 l_ctx
= nfs_get_lock_context(nfs_file_open_context(filp
));
789 if (!IS_ERR(l_ctx
)) {
790 status
= nfs_iocounter_wait(&l_ctx
->io_count
);
791 nfs_put_lock_context(l_ctx
);
796 /* NOTE: special case
797 * If we're signalled while cleaning up locks on process exit, we
798 * still need to complete the unlock.
801 * Use local locking if mounted with "-onolock" or with appropriate
805 status
= NFS_PROTO(inode
)->lock(filp
, cmd
, fl
);
807 status
= do_vfs_lock(filp
, fl
);
812 is_time_granular(struct timespec
*ts
) {
813 return ((ts
->tv_sec
== 0) && (ts
->tv_nsec
<= 1000));
817 do_setlk(struct file
*filp
, int cmd
, struct file_lock
*fl
, int is_local
)
819 struct inode
*inode
= filp
->f_mapping
->host
;
823 * Flush all pending writes before doing anything
826 status
= nfs_sync_mapping(filp
->f_mapping
);
831 * Use local locking if mounted with "-onolock" or with appropriate
835 status
= NFS_PROTO(inode
)->lock(filp
, cmd
, fl
);
837 status
= do_vfs_lock(filp
, fl
);
842 * Revalidate the cache if the server has time stamps granular
843 * enough to detect subsecond changes. Otherwise, clear the
844 * cache to prevent missing any changes.
846 * This makes locking act as a cache coherency point.
848 nfs_sync_mapping(filp
->f_mapping
);
849 if (!NFS_PROTO(inode
)->have_delegation(inode
, FMODE_READ
)) {
850 if (is_time_granular(&NFS_SERVER(inode
)->time_delta
))
851 __nfs_revalidate_inode(NFS_SERVER(inode
), inode
);
853 nfs_zap_caches(inode
);
860 * Lock a (portion of) a file
862 int nfs_lock(struct file
*filp
, int cmd
, struct file_lock
*fl
)
864 struct inode
*inode
= filp
->f_mapping
->host
;
868 dprintk("NFS: lock(%pD2, t=%x, fl=%x, r=%lld:%lld)\n",
869 filp
, fl
->fl_type
, fl
->fl_flags
,
870 (long long)fl
->fl_start
, (long long)fl
->fl_end
);
872 nfs_inc_stats(inode
, NFSIOS_VFSLOCK
);
874 /* No mandatory locks over NFS */
875 if (__mandatory_lock(inode
) && fl
->fl_type
!= F_UNLCK
)
878 if (NFS_SERVER(inode
)->flags
& NFS_MOUNT_LOCAL_FCNTL
)
881 if (NFS_PROTO(inode
)->lock_check_bounds
!= NULL
) {
882 ret
= NFS_PROTO(inode
)->lock_check_bounds(fl
);
888 ret
= do_getlk(filp
, cmd
, fl
, is_local
);
889 else if (fl
->fl_type
== F_UNLCK
)
890 ret
= do_unlk(filp
, cmd
, fl
, is_local
);
892 ret
= do_setlk(filp
, cmd
, fl
, is_local
);
896 EXPORT_SYMBOL_GPL(nfs_lock
);
899 * Lock a (portion of) a file
901 int nfs_flock(struct file
*filp
, int cmd
, struct file_lock
*fl
)
903 struct inode
*inode
= filp
->f_mapping
->host
;
906 dprintk("NFS: flock(%pD2, t=%x, fl=%x)\n",
907 filp
, fl
->fl_type
, fl
->fl_flags
);
909 if (!(fl
->fl_flags
& FL_FLOCK
))
913 * The NFSv4 protocol doesn't support LOCK_MAND, which is not part of
914 * any standard. In principle we might be able to support LOCK_MAND
915 * on NFSv2/3 since NLMv3/4 support DOS share modes, but for now the
916 * NFS code is not set up for it.
918 if (fl
->fl_type
& LOCK_MAND
)
921 if (NFS_SERVER(inode
)->flags
& NFS_MOUNT_LOCAL_FLOCK
)
924 /* We're simulating flock() locks using posix locks on the server */
925 if (fl
->fl_type
== F_UNLCK
)
926 return do_unlk(filp
, cmd
, fl
, is_local
);
927 return do_setlk(filp
, cmd
, fl
, is_local
);
929 EXPORT_SYMBOL_GPL(nfs_flock
);
931 const struct file_operations nfs_file_operations
= {
932 .llseek
= nfs_file_llseek
,
933 .read_iter
= nfs_file_read
,
934 .write_iter
= nfs_file_write
,
935 .mmap
= nfs_file_mmap
,
936 .open
= nfs_file_open
,
937 .flush
= nfs_file_flush
,
938 .release
= nfs_file_release
,
939 .fsync
= nfs_file_fsync
,
942 .splice_read
= nfs_file_splice_read
,
943 .splice_write
= iter_file_splice_write
,
944 .check_flags
= nfs_check_flags
,
945 .setlease
= simple_nosetlease
,
947 EXPORT_SYMBOL_GPL(nfs_file_operations
);