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,
68 .mmap = nfs_file_mmap,
70 .mmap = generic_file_mmap,
72 .open = nfs_file_open,
73 .flush = nfs_file_flush,
74 .release = nfs_file_release,
75 .fsync = nfs_file_fsync,
78 .splice_read = nfs_file_splice_read,
79 .check_flags = nfs_check_flags,
80 .setlease = nfs_setlease,
83 const struct inode_operations nfs_file_inode_operations = {
84 .permission = nfs_permission,
85 .getattr = nfs_getattr,
86 .setattr = nfs_setattr,
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,
99 #endif /* CONFIG_NFS_v3 */
101 /* Hack for future NFS swap support */
103 # define IS_SWAPFILE(inode) (0)
106 static int nfs_check_flags(int flags)
108 if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT))
118 nfs_file_open(struct inode *inode, struct file *filp)
122 res = nfs_check_flags(filp->f_flags);
126 nfs_inc_stats(inode, NFSIOS_VFSOPEN);
128 res = NFS_PROTO(inode)->file_open(inode, filp);
134 nfs_file_release(struct inode *inode, struct file *filp)
136 /* Ensure that dirty pages are flushed out with the right creds */
137 if (filp->f_mode & FMODE_WRITE)
138 nfs_wb_all(filp->f_path.dentry->d_inode);
139 nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
140 return NFS_PROTO(inode)->file_release(inode, filp);
144 * nfs_revalidate_size - Revalidate the file size
145 * @inode - pointer to inode struct
146 * @file - pointer to struct file
148 * Revalidates the file length. This is basically a wrapper around
149 * nfs_revalidate_inode() that takes into account the fact that we may
150 * have cached writes (in which case we don't care about the server's
151 * idea of what the file length is), or O_DIRECT (in which case we
152 * shouldn't trust the cache).
154 static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
156 struct nfs_server *server = NFS_SERVER(inode);
157 struct nfs_inode *nfsi = NFS_I(inode);
159 if (server->flags & NFS_MOUNT_NOAC)
161 if (filp->f_flags & O_DIRECT)
163 if (nfsi->npages != 0)
165 if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode))
168 return __nfs_revalidate_inode(server, inode);
171 static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
173 dfprintk(VFS, "NFS: llseek file(%s/%s, %lld, %d)\n",
174 filp->f_path.dentry->d_parent->d_name.name,
175 filp->f_path.dentry->d_name.name,
178 /* origin == SEEK_END => we must revalidate the cached file length */
179 if (origin == SEEK_END) {
180 struct inode *inode = filp->f_mapping->host;
181 int retval = nfs_revalidate_file_size(inode, filp);
183 return (loff_t)retval;
185 return remote_llseek(filp, offset, origin);
189 * Helper for nfs_file_flush() and nfs_file_fsync()
191 * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
192 * disk, but it retrieves and clears ctx->error after synching, despite
193 * the two being set at the same time in nfs_context_set_write_error().
194 * This is because the former is used to notify the _next_ call to
195 * nfs_file_write() that a write error occured, and hence cause it to
196 * fall back to doing a synchronous write.
198 static int nfs_do_fsync(struct nfs_open_context *ctx, struct inode *inode)
200 int have_error, status;
203 have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
204 status = nfs_wb_all(inode);
205 have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
207 ret = xchg(&ctx->error, 0);
214 * Flush all dirty pages, and check for write errors.
218 nfs_file_flush(struct file *file, fl_owner_t id)
220 struct nfs_open_context *ctx = nfs_file_open_context(file);
221 struct inode *inode = file->f_path.dentry->d_inode;
224 dfprintk(VFS, "nfs: flush(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);
226 if ((file->f_mode & FMODE_WRITE) == 0)
228 nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
230 /* Ensure that data+attribute caches are up to date after close() */
231 status = nfs_do_fsync(ctx, inode);
233 nfs_revalidate_inode(NFS_SERVER(inode), inode);
238 nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
239 unsigned long nr_segs, loff_t pos)
241 struct dentry * dentry = iocb->ki_filp->f_path.dentry;
242 struct inode * inode = dentry->d_inode;
244 size_t count = iov_length(iov, nr_segs);
246 if (iocb->ki_filp->f_flags & O_DIRECT)
247 return nfs_file_direct_read(iocb, iov, nr_segs, pos);
249 dfprintk(VFS, "nfs: read(%s/%s, %lu@%lu)\n",
250 dentry->d_parent->d_name.name, dentry->d_name.name,
251 (unsigned long) count, (unsigned long) pos);
253 result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
254 nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
256 result = generic_file_aio_read(iocb, iov, nr_segs, pos);
261 nfs_file_splice_read(struct file *filp, loff_t *ppos,
262 struct pipe_inode_info *pipe, size_t count,
265 struct dentry *dentry = filp->f_path.dentry;
266 struct inode *inode = dentry->d_inode;
269 dfprintk(VFS, "nfs: splice_read(%s/%s, %lu@%Lu)\n",
270 dentry->d_parent->d_name.name, dentry->d_name.name,
271 (unsigned long) count, (unsigned long long) *ppos);
273 res = nfs_revalidate_mapping(inode, filp->f_mapping);
275 res = generic_file_splice_read(filp, ppos, pipe, count, flags);
280 nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
282 struct dentry *dentry = file->f_path.dentry;
283 struct inode *inode = dentry->d_inode;
286 dfprintk(VFS, "nfs: mmap(%s/%s)\n",
287 dentry->d_parent->d_name.name, dentry->d_name.name);
289 status = nfs_revalidate_mapping(inode, file->f_mapping);
291 vma->vm_ops = &nfs_file_vm_ops;
292 vma->vm_flags |= VM_CAN_NONLINEAR;
299 * Flush any dirty pages for this process, and check for write errors.
300 * The return status from this call provides a reliable indication of
301 * whether any write errors occurred for this process.
304 nfs_file_fsync(struct file *file, struct dentry *dentry, int datasync)
306 struct nfs_open_context *ctx = nfs_file_open_context(file);
307 struct inode *inode = dentry->d_inode;
309 dfprintk(VFS, "NFS: fsync file(%s/%s) datasync %d\n",
310 dentry->d_parent->d_name.name, dentry->d_name.name,
313 nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
314 return nfs_do_fsync(ctx, inode);
318 * This does the "real" work of the write. We must allocate and lock the
319 * page to be sent back to the generic routine, which then copies the
320 * data from user space.
322 * If the writer ends up delaying the write, the writer needs to
323 * increment the page use counts until he is done with the page.
325 static int nfs_write_begin(struct file *file, struct address_space *mapping,
326 loff_t pos, unsigned len, unsigned flags,
327 struct page **pagep, void **fsdata)
332 index = pos >> PAGE_CACHE_SHIFT;
334 page = __grab_cache_page(mapping, index);
339 ret = nfs_flush_incompatible(file, page);
342 page_cache_release(page);
347 static int nfs_write_end(struct file *file, struct address_space *mapping,
348 loff_t pos, unsigned len, unsigned copied,
349 struct page *page, void *fsdata)
351 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
355 * Zero any uninitialised parts of the page, and then mark the page
356 * as up to date if it turns out that we're extending the file.
358 if (!PageUptodate(page)) {
359 unsigned pglen = nfs_page_length(page);
360 unsigned end = offset + len;
363 zero_user_segments(page, 0, offset,
364 end, PAGE_CACHE_SIZE);
365 SetPageUptodate(page);
366 } else if (end >= pglen) {
367 zero_user_segment(page, end, PAGE_CACHE_SIZE);
369 SetPageUptodate(page);
371 zero_user_segment(page, pglen, PAGE_CACHE_SIZE);
375 status = nfs_updatepage(file, page, offset, copied);
379 page_cache_release(page);
386 static void nfs_invalidate_page(struct page *page, unsigned long offset)
390 /* Cancel any unstarted writes on this page */
391 nfs_wb_page_cancel(page->mapping->host, page);
394 static int nfs_release_page(struct page *page, gfp_t gfp)
396 /* If PagePrivate() is set, then the page is not freeable */
400 static int nfs_launder_page(struct page *page)
402 return nfs_wb_page(page->mapping->host, page);
405 const struct address_space_operations nfs_file_aops = {
406 .readpage = nfs_readpage,
407 .readpages = nfs_readpages,
408 .set_page_dirty = __set_page_dirty_nobuffers,
409 .writepage = nfs_writepage,
410 .writepages = nfs_writepages,
411 .write_begin = nfs_write_begin,
412 .write_end = nfs_write_end,
413 .invalidatepage = nfs_invalidate_page,
414 .releasepage = nfs_release_page,
415 .direct_IO = nfs_direct_IO,
416 .launder_page = nfs_launder_page,
419 static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
421 struct file *filp = vma->vm_file;
424 struct address_space *mapping;
427 mapping = page->mapping;
428 if (mapping != vma->vm_file->f_path.dentry->d_inode->i_mapping)
432 pagelen = nfs_page_length(page);
436 ret = nfs_flush_incompatible(filp, page);
440 ret = nfs_updatepage(filp, page, 0, pagelen);
448 static struct vm_operations_struct nfs_file_vm_ops = {
449 .fault = filemap_fault,
450 .page_mkwrite = nfs_vm_page_mkwrite,
453 static int nfs_need_sync_write(struct file *filp, struct inode *inode)
455 struct nfs_open_context *ctx;
457 if (IS_SYNC(inode) || (filp->f_flags & O_SYNC))
459 ctx = nfs_file_open_context(filp);
460 if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags))
465 static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
466 unsigned long nr_segs, loff_t pos)
468 struct dentry * dentry = iocb->ki_filp->f_path.dentry;
469 struct inode * inode = dentry->d_inode;
471 size_t count = iov_length(iov, nr_segs);
473 if (iocb->ki_filp->f_flags & O_DIRECT)
474 return nfs_file_direct_write(iocb, iov, nr_segs, pos);
476 dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%Ld)\n",
477 dentry->d_parent->d_name.name, dentry->d_name.name,
478 inode->i_ino, (unsigned long) count, (long long) pos);
481 if (IS_SWAPFILE(inode))
484 * O_APPEND implies that we must revalidate the file length.
486 if (iocb->ki_filp->f_flags & O_APPEND) {
487 result = nfs_revalidate_file_size(inode, iocb->ki_filp);
496 nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
497 result = generic_file_aio_write(iocb, iov, nr_segs, pos);
498 /* Return error values for O_SYNC and IS_SYNC() */
499 if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) {
500 int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode);
508 printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
512 static int do_getlk(struct file *filp, int cmd, struct file_lock *fl)
514 struct inode *inode = filp->f_mapping->host;
518 /* Try local locking first */
519 posix_test_lock(filp, fl);
520 if (fl->fl_type != F_UNLCK) {
521 /* found a conflict */
525 if (nfs_have_delegation(inode, FMODE_READ))
528 if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)
531 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
536 fl->fl_type = F_UNLCK;
540 static int do_vfs_lock(struct file *file, struct file_lock *fl)
543 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
545 res = posix_lock_file_wait(file, fl);
548 res = flock_lock_file_wait(file, fl);
554 dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager"
560 static int do_unlk(struct file *filp, int cmd, struct file_lock *fl)
562 struct inode *inode = filp->f_mapping->host;
566 * Flush all pending writes before doing anything
569 nfs_sync_mapping(filp->f_mapping);
571 /* NOTE: special case
572 * If we're signalled while cleaning up locks on process exit, we
573 * still need to complete the unlock.
576 /* Use local locking if mounted with "-onolock" */
577 if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
578 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
580 status = do_vfs_lock(filp, fl);
585 static int do_setlk(struct file *filp, int cmd, struct file_lock *fl)
587 struct inode *inode = filp->f_mapping->host;
591 * Flush all pending writes before doing anything
594 status = nfs_sync_mapping(filp->f_mapping);
599 /* Use local locking if mounted with "-onolock" */
600 if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
601 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
603 status = do_vfs_lock(filp, fl);
608 * Make sure we clear the cache whenever we try to get the lock.
609 * This makes locking act as a cache coherency point.
611 nfs_sync_mapping(filp->f_mapping);
612 if (!nfs_have_delegation(inode, FMODE_READ))
613 nfs_zap_caches(inode);
619 * Lock a (portion of) a file
621 static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
623 struct inode * inode = filp->f_mapping->host;
626 dprintk("NFS: nfs_lock(f=%s/%ld, t=%x, fl=%x, r=%Ld:%Ld)\n",
627 inode->i_sb->s_id, inode->i_ino,
628 fl->fl_type, fl->fl_flags,
629 (long long)fl->fl_start, (long long)fl->fl_end);
630 nfs_inc_stats(inode, NFSIOS_VFSLOCK);
632 /* No mandatory locks over NFS */
633 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
636 if (NFS_PROTO(inode)->lock_check_bounds != NULL) {
637 ret = NFS_PROTO(inode)->lock_check_bounds(fl);
643 ret = do_getlk(filp, cmd, fl);
644 else if (fl->fl_type == F_UNLCK)
645 ret = do_unlk(filp, cmd, fl);
647 ret = do_setlk(filp, cmd, fl);
653 * Lock a (portion of) a file
655 static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
657 dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n",
658 filp->f_path.dentry->d_inode->i_sb->s_id,
659 filp->f_path.dentry->d_inode->i_ino,
660 fl->fl_type, fl->fl_flags);
663 * No BSD flocks over NFS allowed.
664 * Note: we could try to fake a POSIX lock request here by
665 * using ((u32) filp | 0x80000000) or some such as the pid.
666 * Not sure whether that would be unique, though, or whether
667 * that would break in other places.
669 if (!(fl->fl_flags & FL_FLOCK))
672 /* We're simulating flock() locks using posix locks on the server */
673 fl->fl_owner = (fl_owner_t)filp;
675 fl->fl_end = OFFSET_MAX;
677 if (fl->fl_type == F_UNLCK)
678 return do_unlk(filp, cmd, fl);
679 return do_setlk(filp, cmd, fl);
682 static int nfs_setlease(struct file *file, long arg, struct file_lock **fl)
685 * There is no protocol support for leases, so we have no way
686 * to implement them correctly in the face of opens by other