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/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>
27 #include <linux/slab.h>
28 #include <linux/pagemap.h>
29 #include <linux/smp_lock.h>
30 #include <linux/aio.h>
32 #include <asm/uaccess.h>
33 #include <asm/system.h>
35 #include "delegation.h"
39 #define NFSDBG_FACILITY NFSDBG_FILE
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
);
59 static struct vm_operations_struct nfs_file_vm_ops
;
61 const struct file_operations nfs_file_operations
= {
62 .llseek
= nfs_file_llseek
,
64 .write
= do_sync_write
,
65 .aio_read
= nfs_file_read
,
66 .aio_write
= nfs_file_write
,
67 .mmap
= nfs_file_mmap
,
68 .open
= nfs_file_open
,
69 .flush
= nfs_file_flush
,
70 .release
= nfs_file_release
,
71 .fsync
= nfs_file_fsync
,
74 .splice_read
= nfs_file_splice_read
,
75 .check_flags
= nfs_check_flags
,
76 .setlease
= nfs_setlease
,
79 const struct inode_operations nfs_file_inode_operations
= {
80 .permission
= nfs_permission
,
81 .getattr
= nfs_getattr
,
82 .setattr
= nfs_setattr
,
86 const struct inode_operations nfs3_file_inode_operations
= {
87 .permission
= nfs_permission
,
88 .getattr
= nfs_getattr
,
89 .setattr
= nfs_setattr
,
90 .listxattr
= nfs3_listxattr
,
91 .getxattr
= nfs3_getxattr
,
92 .setxattr
= nfs3_setxattr
,
93 .removexattr
= nfs3_removexattr
,
95 #endif /* CONFIG_NFS_v3 */
97 /* Hack for future NFS swap support */
99 # define IS_SWAPFILE(inode) (0)
102 static int nfs_check_flags(int flags
)
104 if ((flags
& (O_APPEND
| O_DIRECT
)) == (O_APPEND
| O_DIRECT
))
114 nfs_file_open(struct inode
*inode
, struct file
*filp
)
118 dprintk("NFS: open file(%s/%s)\n",
119 filp
->f_path
.dentry
->d_parent
->d_name
.name
,
120 filp
->f_path
.dentry
->d_name
.name
);
122 res
= nfs_check_flags(filp
->f_flags
);
126 nfs_inc_stats(inode
, NFSIOS_VFSOPEN
);
127 res
= nfs_open(inode
, filp
);
132 nfs_file_release(struct inode
*inode
, struct file
*filp
)
134 struct dentry
*dentry
= filp
->f_path
.dentry
;
136 dprintk("NFS: release(%s/%s)\n",
137 dentry
->d_parent
->d_name
.name
,
138 dentry
->d_name
.name
);
140 nfs_inc_stats(inode
, NFSIOS_VFSRELEASE
);
141 return nfs_release(inode
, filp
);
145 * nfs_revalidate_size - Revalidate the file size
146 * @inode - pointer to inode struct
147 * @file - pointer to struct file
149 * Revalidates the file length. This is basically a wrapper around
150 * nfs_revalidate_inode() that takes into account the fact that we may
151 * have cached writes (in which case we don't care about the server's
152 * idea of what the file length is), or O_DIRECT (in which case we
153 * shouldn't trust the cache).
155 static int nfs_revalidate_file_size(struct inode
*inode
, struct file
*filp
)
157 struct nfs_server
*server
= NFS_SERVER(inode
);
158 struct nfs_inode
*nfsi
= NFS_I(inode
);
160 if (server
->flags
& NFS_MOUNT_NOAC
)
162 if (filp
->f_flags
& O_DIRECT
)
164 if (nfsi
->npages
!= 0)
166 if (!(nfsi
->cache_validity
& NFS_INO_REVAL_PAGECACHE
) && !nfs_attribute_timeout(inode
))
169 return __nfs_revalidate_inode(server
, inode
);
172 static loff_t
nfs_file_llseek(struct file
*filp
, loff_t offset
, int origin
)
176 dprintk("NFS: llseek file(%s/%s, %lld, %d)\n",
177 filp
->f_path
.dentry
->d_parent
->d_name
.name
,
178 filp
->f_path
.dentry
->d_name
.name
,
181 /* origin == SEEK_END => we must revalidate the cached file length */
182 if (origin
== SEEK_END
) {
183 struct inode
*inode
= filp
->f_mapping
->host
;
185 int retval
= nfs_revalidate_file_size(inode
, filp
);
187 return (loff_t
)retval
;
189 spin_lock(&inode
->i_lock
);
190 loff
= generic_file_llseek_unlocked(filp
, offset
, origin
);
191 spin_unlock(&inode
->i_lock
);
193 loff
= generic_file_llseek_unlocked(filp
, offset
, origin
);
198 * Helper for nfs_file_flush() and nfs_file_fsync()
200 * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
201 * disk, but it retrieves and clears ctx->error after synching, despite
202 * the two being set at the same time in nfs_context_set_write_error().
203 * This is because the former is used to notify the _next_ call to
204 * nfs_file_write() that a write error occured, and hence cause it to
205 * fall back to doing a synchronous write.
207 static int nfs_do_fsync(struct nfs_open_context
*ctx
, struct inode
*inode
)
209 int have_error
, status
;
212 have_error
= test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE
, &ctx
->flags
);
213 status
= nfs_wb_all(inode
);
214 have_error
|= test_bit(NFS_CONTEXT_ERROR_WRITE
, &ctx
->flags
);
216 ret
= xchg(&ctx
->error
, 0);
223 * Flush all dirty pages, and check for write errors.
226 nfs_file_flush(struct file
*file
, fl_owner_t id
)
228 struct nfs_open_context
*ctx
= nfs_file_open_context(file
);
229 struct dentry
*dentry
= file
->f_path
.dentry
;
230 struct inode
*inode
= dentry
->d_inode
;
232 dprintk("NFS: flush(%s/%s)\n",
233 dentry
->d_parent
->d_name
.name
,
234 dentry
->d_name
.name
);
236 if ((file
->f_mode
& FMODE_WRITE
) == 0)
238 nfs_inc_stats(inode
, NFSIOS_VFSFLUSH
);
240 /* Flush writes to the server and return any errors */
241 return nfs_do_fsync(ctx
, inode
);
245 nfs_file_read(struct kiocb
*iocb
, const struct iovec
*iov
,
246 unsigned long nr_segs
, loff_t pos
)
248 struct dentry
* dentry
= iocb
->ki_filp
->f_path
.dentry
;
249 struct inode
* inode
= dentry
->d_inode
;
251 size_t count
= iov_length(iov
, nr_segs
);
253 if (iocb
->ki_filp
->f_flags
& O_DIRECT
)
254 return nfs_file_direct_read(iocb
, iov
, nr_segs
, pos
);
256 dprintk("NFS: read(%s/%s, %lu@%lu)\n",
257 dentry
->d_parent
->d_name
.name
, dentry
->d_name
.name
,
258 (unsigned long) count
, (unsigned long) pos
);
260 result
= nfs_revalidate_mapping(inode
, iocb
->ki_filp
->f_mapping
);
261 nfs_add_stats(inode
, NFSIOS_NORMALREADBYTES
, count
);
263 result
= generic_file_aio_read(iocb
, iov
, nr_segs
, pos
);
268 nfs_file_splice_read(struct file
*filp
, loff_t
*ppos
,
269 struct pipe_inode_info
*pipe
, size_t count
,
272 struct dentry
*dentry
= filp
->f_path
.dentry
;
273 struct inode
*inode
= dentry
->d_inode
;
276 dprintk("NFS: splice_read(%s/%s, %lu@%Lu)\n",
277 dentry
->d_parent
->d_name
.name
, dentry
->d_name
.name
,
278 (unsigned long) count
, (unsigned long long) *ppos
);
280 res
= nfs_revalidate_mapping(inode
, filp
->f_mapping
);
282 res
= generic_file_splice_read(filp
, ppos
, pipe
, count
, flags
);
287 nfs_file_mmap(struct file
* file
, struct vm_area_struct
* vma
)
289 struct dentry
*dentry
= file
->f_path
.dentry
;
290 struct inode
*inode
= dentry
->d_inode
;
293 dprintk("NFS: mmap(%s/%s)\n",
294 dentry
->d_parent
->d_name
.name
, dentry
->d_name
.name
);
296 /* Note: generic_file_mmap() returns ENOSYS on nommu systems
297 * so we call that before revalidating the mapping
299 status
= generic_file_mmap(file
, vma
);
301 vma
->vm_ops
= &nfs_file_vm_ops
;
302 status
= nfs_revalidate_mapping(inode
, file
->f_mapping
);
308 * Flush any dirty pages for this process, and check for write errors.
309 * The return status from this call provides a reliable indication of
310 * whether any write errors occurred for this process.
313 nfs_file_fsync(struct file
*file
, struct dentry
*dentry
, int datasync
)
315 struct nfs_open_context
*ctx
= nfs_file_open_context(file
);
316 struct inode
*inode
= dentry
->d_inode
;
318 dprintk("NFS: fsync file(%s/%s) datasync %d\n",
319 dentry
->d_parent
->d_name
.name
, dentry
->d_name
.name
,
322 nfs_inc_stats(inode
, NFSIOS_VFSFSYNC
);
323 return nfs_do_fsync(ctx
, inode
);
327 * This does the "real" work of the write. We must allocate and lock the
328 * page to be sent back to the generic routine, which then copies the
329 * data from user space.
331 * If the writer ends up delaying the write, the writer needs to
332 * increment the page use counts until he is done with the page.
334 static int nfs_write_begin(struct file
*file
, struct address_space
*mapping
,
335 loff_t pos
, unsigned len
, unsigned flags
,
336 struct page
**pagep
, void **fsdata
)
341 index
= pos
>> PAGE_CACHE_SHIFT
;
343 dfprintk(PAGECACHE
, "NFS: write_begin(%s/%s(%ld), %u@%lld)\n",
344 file
->f_path
.dentry
->d_parent
->d_name
.name
,
345 file
->f_path
.dentry
->d_name
.name
,
346 mapping
->host
->i_ino
, len
, (long long) pos
);
349 * Prevent starvation issues if someone is doing a consistency
352 ret
= wait_on_bit(&NFS_I(mapping
->host
)->flags
, NFS_INO_FLUSHING
,
353 nfs_wait_bit_killable
, TASK_KILLABLE
);
357 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
362 ret
= nfs_flush_incompatible(file
, page
);
365 page_cache_release(page
);
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
)
374 unsigned offset
= pos
& (PAGE_CACHE_SIZE
- 1);
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
);
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.
386 if (!PageUptodate(page
)) {
387 unsigned pglen
= nfs_page_length(page
);
388 unsigned end
= offset
+ len
;
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
);
397 SetPageUptodate(page
);
399 zero_user_segment(page
, pglen
, PAGE_CACHE_SIZE
);
402 status
= nfs_updatepage(file
, page
, offset
, copied
);
405 page_cache_release(page
);
413 * Partially or wholly invalidate a page
414 * - Release the private state associated with a page if undergoing complete
416 * - Called if either PG_private or PG_private_2 is set on the page
417 * - Caller holds page lock
419 static void nfs_invalidate_page(struct page
*page
, unsigned long offset
)
421 dfprintk(PAGECACHE
, "NFS: invalidate_page(%p, %lu)\n", page
, offset
);
425 /* Cancel any unstarted writes on this page */
426 nfs_wb_page_cancel(page
->mapping
->host
, page
);
430 * Attempt to release the private state associated with a page
431 * - Called if either PG_private or PG_private_2 is set on the page
432 * - Caller holds page lock
433 * - Return true (may release page) or false (may not)
435 static int nfs_release_page(struct page
*page
, gfp_t gfp
)
437 dfprintk(PAGECACHE
, "NFS: release_page(%p)\n", page
);
439 /* If PagePrivate() is set, then the page is not freeable */
444 * Attempt to clear the private state associated with a page when an error
445 * occurs that requires the cached contents of an inode to be written back or
447 * - Called if either PG_private or PG_private_2 is set on the page
448 * - Caller holds page lock
449 * - Return 0 if successful, -error otherwise
451 static int nfs_launder_page(struct page
*page
)
453 struct inode
*inode
= page
->mapping
->host
;
455 dfprintk(PAGECACHE
, "NFS: launder_page(%ld, %llu)\n",
456 inode
->i_ino
, (long long)page_offset(page
));
458 return nfs_wb_page(inode
, page
);
461 const struct address_space_operations nfs_file_aops
= {
462 .readpage
= nfs_readpage
,
463 .readpages
= nfs_readpages
,
464 .set_page_dirty
= __set_page_dirty_nobuffers
,
465 .writepage
= nfs_writepage
,
466 .writepages
= nfs_writepages
,
467 .write_begin
= nfs_write_begin
,
468 .write_end
= nfs_write_end
,
469 .invalidatepage
= nfs_invalidate_page
,
470 .releasepage
= nfs_release_page
,
471 .direct_IO
= nfs_direct_IO
,
472 .launder_page
= nfs_launder_page
,
476 * Notification that a PTE pointing to an NFS page is about to be made
477 * writable, implying that someone is about to modify the page through a
478 * shared-writable mapping
480 static int nfs_vm_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
482 struct page
*page
= vmf
->page
;
483 struct file
*filp
= vma
->vm_file
;
484 struct dentry
*dentry
= filp
->f_path
.dentry
;
487 struct address_space
*mapping
;
489 dfprintk(PAGECACHE
, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n",
490 dentry
->d_parent
->d_name
.name
, dentry
->d_name
.name
,
491 filp
->f_mapping
->host
->i_ino
,
492 (long long)page_offset(page
));
495 mapping
= page
->mapping
;
496 if (mapping
!= dentry
->d_inode
->i_mapping
)
500 pagelen
= nfs_page_length(page
);
504 ret
= nfs_flush_incompatible(filp
, page
);
508 ret
= nfs_updatepage(filp
, page
, 0, pagelen
);
514 ret
= VM_FAULT_SIGBUS
;
518 static struct vm_operations_struct nfs_file_vm_ops
= {
519 .fault
= filemap_fault
,
520 .page_mkwrite
= nfs_vm_page_mkwrite
,
523 static int nfs_need_sync_write(struct file
*filp
, struct inode
*inode
)
525 struct nfs_open_context
*ctx
;
527 if (IS_SYNC(inode
) || (filp
->f_flags
& O_SYNC
))
529 ctx
= nfs_file_open_context(filp
);
530 if (test_bit(NFS_CONTEXT_ERROR_WRITE
, &ctx
->flags
))
535 static ssize_t
nfs_file_write(struct kiocb
*iocb
, const struct iovec
*iov
,
536 unsigned long nr_segs
, loff_t pos
)
538 struct dentry
* dentry
= iocb
->ki_filp
->f_path
.dentry
;
539 struct inode
* inode
= dentry
->d_inode
;
541 size_t count
= iov_length(iov
, nr_segs
);
543 if (iocb
->ki_filp
->f_flags
& O_DIRECT
)
544 return nfs_file_direct_write(iocb
, iov
, nr_segs
, pos
);
546 dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
547 dentry
->d_parent
->d_name
.name
, dentry
->d_name
.name
,
548 (unsigned long) count
, (long long) pos
);
551 if (IS_SWAPFILE(inode
))
554 * O_APPEND implies that we must revalidate the file length.
556 if (iocb
->ki_filp
->f_flags
& O_APPEND
) {
557 result
= nfs_revalidate_file_size(inode
, iocb
->ki_filp
);
566 nfs_add_stats(inode
, NFSIOS_NORMALWRITTENBYTES
, count
);
567 result
= generic_file_aio_write(iocb
, iov
, nr_segs
, pos
);
568 /* Return error values for O_SYNC and IS_SYNC() */
569 if (result
>= 0 && nfs_need_sync_write(iocb
->ki_filp
, inode
)) {
570 int err
= nfs_do_fsync(nfs_file_open_context(iocb
->ki_filp
), inode
);
578 printk(KERN_INFO
"NFS: attempt to write to active swap file!\n");
582 static int do_getlk(struct file
*filp
, int cmd
, struct file_lock
*fl
)
584 struct inode
*inode
= filp
->f_mapping
->host
;
588 /* Try local locking first */
589 posix_test_lock(filp
, fl
);
590 if (fl
->fl_type
!= F_UNLCK
) {
591 /* found a conflict */
595 if (nfs_have_delegation(inode
, FMODE_READ
))
598 if (NFS_SERVER(inode
)->flags
& NFS_MOUNT_NONLM
)
601 status
= NFS_PROTO(inode
)->lock(filp
, cmd
, fl
);
606 fl
->fl_type
= F_UNLCK
;
610 static int do_vfs_lock(struct file
*file
, struct file_lock
*fl
)
613 switch (fl
->fl_flags
& (FL_POSIX
|FL_FLOCK
)) {
615 res
= posix_lock_file_wait(file
, fl
);
618 res
= flock_lock_file_wait(file
, fl
);
624 dprintk(KERN_WARNING
"%s: VFS is out of sync with lock manager"
630 static int do_unlk(struct file
*filp
, int cmd
, struct file_lock
*fl
)
632 struct inode
*inode
= filp
->f_mapping
->host
;
636 * Flush all pending writes before doing anything
639 nfs_sync_mapping(filp
->f_mapping
);
641 /* NOTE: special case
642 * If we're signalled while cleaning up locks on process exit, we
643 * still need to complete the unlock.
646 /* Use local locking if mounted with "-onolock" */
647 if (!(NFS_SERVER(inode
)->flags
& NFS_MOUNT_NONLM
))
648 status
= NFS_PROTO(inode
)->lock(filp
, cmd
, fl
);
650 status
= do_vfs_lock(filp
, fl
);
655 static int do_setlk(struct file
*filp
, int cmd
, struct file_lock
*fl
)
657 struct inode
*inode
= filp
->f_mapping
->host
;
661 * Flush all pending writes before doing anything
664 status
= nfs_sync_mapping(filp
->f_mapping
);
669 /* Use local locking if mounted with "-onolock" */
670 if (!(NFS_SERVER(inode
)->flags
& NFS_MOUNT_NONLM
))
671 status
= NFS_PROTO(inode
)->lock(filp
, cmd
, fl
);
673 status
= do_vfs_lock(filp
, fl
);
678 * Make sure we clear the cache whenever we try to get the lock.
679 * This makes locking act as a cache coherency point.
681 nfs_sync_mapping(filp
->f_mapping
);
682 if (!nfs_have_delegation(inode
, FMODE_READ
))
683 nfs_zap_caches(inode
);
689 * Lock a (portion of) a file
691 static int nfs_lock(struct file
*filp
, int cmd
, struct file_lock
*fl
)
693 struct inode
*inode
= filp
->f_mapping
->host
;
696 dprintk("NFS: lock(%s/%s, t=%x, fl=%x, r=%lld:%lld)\n",
697 filp
->f_path
.dentry
->d_parent
->d_name
.name
,
698 filp
->f_path
.dentry
->d_name
.name
,
699 fl
->fl_type
, fl
->fl_flags
,
700 (long long)fl
->fl_start
, (long long)fl
->fl_end
);
702 nfs_inc_stats(inode
, NFSIOS_VFSLOCK
);
704 /* No mandatory locks over NFS */
705 if (__mandatory_lock(inode
) && fl
->fl_type
!= F_UNLCK
)
708 if (NFS_PROTO(inode
)->lock_check_bounds
!= NULL
) {
709 ret
= NFS_PROTO(inode
)->lock_check_bounds(fl
);
715 ret
= do_getlk(filp
, cmd
, fl
);
716 else if (fl
->fl_type
== F_UNLCK
)
717 ret
= do_unlk(filp
, cmd
, fl
);
719 ret
= do_setlk(filp
, cmd
, fl
);
725 * Lock a (portion of) a file
727 static int nfs_flock(struct file
*filp
, int cmd
, struct file_lock
*fl
)
729 dprintk("NFS: flock(%s/%s, t=%x, fl=%x)\n",
730 filp
->f_path
.dentry
->d_parent
->d_name
.name
,
731 filp
->f_path
.dentry
->d_name
.name
,
732 fl
->fl_type
, fl
->fl_flags
);
734 if (!(fl
->fl_flags
& FL_FLOCK
))
737 /* We're simulating flock() locks using posix locks on the server */
738 fl
->fl_owner
= (fl_owner_t
)filp
;
740 fl
->fl_end
= OFFSET_MAX
;
742 if (fl
->fl_type
== F_UNLCK
)
743 return do_unlk(filp
, cmd
, fl
);
744 return do_setlk(filp
, cmd
, fl
);
748 * There is no protocol support for leases, so we have no way to implement
749 * them correctly in the face of opens by other clients.
751 static int nfs_setlease(struct file
*file
, long arg
, struct file_lock
**fl
)
753 dprintk("NFS: setlease(%s/%s, arg=%ld)\n",
754 file
->f_path
.dentry
->d_parent
->d_name
.name
,
755 file
->f_path
.dentry
->d_name
.name
, arg
);