blob: 90f292b520d25eec248a9728b7d61cf20cd061f9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040030#include <linux/aio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32#include <asm/uaccess.h>
33#include <asm/system.h>
34
35#include "delegation.h"
Trond Myklebust94387fb2007-07-22 17:09:05 -040036#include "internal.h"
Chuck Lever91d5b472006-03-20 13:44:14 -050037#include "iostat.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39#define NFSDBG_FACILITY NFSDBG_FILE
40
41static int nfs_file_open(struct inode *, struct file *);
42static int nfs_file_release(struct inode *, struct file *);
Trond Myklebust980802e2005-06-13 11:14:01 -040043static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044static int nfs_file_mmap(struct file *, struct vm_area_struct *);
Jens Axboef0930ff2007-06-01 11:51:43 +020045static 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);
Badari Pulavarty027445c2006-09-30 23:28:46 -070048static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov,
49 unsigned long nr_segs, loff_t pos);
50static ssize_t nfs_file_write(struct kiocb *, const struct iovec *iov,
51 unsigned long nr_segs, loff_t pos);
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -070052static int nfs_file_flush(struct file *, fl_owner_t id);
Chuck Lever54917782008-05-27 16:29:07 -040053static int nfs_file_fsync(struct file *, struct dentry *dentry, int datasync);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054static int nfs_check_flags(int flags);
55static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl);
56static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl);
J. Bruce Fields370f6592007-06-08 15:23:34 -040057static int nfs_setlease(struct file *file, long arg, struct file_lock **fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Trond Myklebust94387fb2007-07-22 17:09:05 -040059static struct vm_operations_struct nfs_file_vm_ops;
60
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080061const struct file_operations nfs_file_operations = {
Trond Myklebust980802e2005-06-13 11:14:01 -040062 .llseek = nfs_file_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 .read = do_sync_read,
64 .write = do_sync_write,
Badari Pulavarty027445c2006-09-30 23:28:46 -070065 .aio_read = nfs_file_read,
66 .aio_write = nfs_file_write,
Bryan Wu240ee832008-04-01 20:23:39 -070067#ifdef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 .mmap = nfs_file_mmap,
Bryan Wu240ee832008-04-01 20:23:39 -070069#else
70 .mmap = generic_file_mmap,
71#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 .open = nfs_file_open,
73 .flush = nfs_file_flush,
74 .release = nfs_file_release,
Chuck Lever54917782008-05-27 16:29:07 -040075 .fsync = nfs_file_fsync,
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 .lock = nfs_lock,
77 .flock = nfs_flock,
Jens Axboef0930ff2007-06-01 11:51:43 +020078 .splice_read = nfs_file_splice_read,
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 .check_flags = nfs_check_flags,
J. Bruce Fields370f6592007-06-08 15:23:34 -040080 .setlease = nfs_setlease,
Linus Torvalds1da177e2005-04-16 15:20:36 -070081};
82
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -080083const struct inode_operations nfs_file_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 .permission = nfs_permission,
85 .getattr = nfs_getattr,
86 .setattr = nfs_setattr,
87};
88
Andreas Gruenbacherb7fa0552005-06-22 17:16:27 +000089#ifdef CONFIG_NFS_V3
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -080090const struct inode_operations nfs3_file_inode_operations = {
Andreas Gruenbacherb7fa0552005-06-22 17:16:27 +000091 .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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101/* Hack for future NFS swap support */
102#ifndef IS_SWAPFILE
103# define IS_SWAPFILE(inode) (0)
104#endif
105
106static 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 */
117static int
118nfs_file_open(struct inode *inode, struct file *filp)
119{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 int res;
121
Chuck Lever6da24bc2008-06-11 17:55:58 -0400122 dprintk("NFS: open file(%s/%s)\n",
Chuck Levercc0dd2d2008-06-11 17:55:42 -0400123 filp->f_path.dentry->d_parent->d_name.name,
124 filp->f_path.dentry->d_name.name);
125
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 res = nfs_check_flags(filp->f_flags);
127 if (res)
128 return res;
129
Chuck Lever91d5b472006-03-20 13:44:14 -0500130 nfs_inc_stats(inode, NFSIOS_VFSOPEN);
Trond Myklebust46cb6502008-06-11 16:32:46 -0400131 res = nfs_open(inode, filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 return res;
133}
134
135static int
136nfs_file_release(struct inode *inode, struct file *filp)
137{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400138 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 /* Ensure that dirty pages are flushed out with the right creds */
145 if (filp->f_mode & FMODE_WRITE)
Chuck Lever6da24bc2008-06-11 17:55:58 -0400146 nfs_wb_all(dentry->d_inode);
Chuck Lever91d5b472006-03-20 13:44:14 -0500147 nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
Trond Myklebust46cb6502008-06-11 16:32:46 -0400148 return nfs_release(inode, filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149}
150
Trond Myklebust980802e2005-06-13 11:14:01 -0400151/**
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 */
162static 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;
Chuck Lever55296802005-08-18 11:24:09 -0700173 if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode))
Trond Myklebustfe51bee2005-06-22 17:16:30 +0000174 return 0;
Trond Myklebust980802e2005-06-13 11:14:01 -0400175force_reval:
176 return __nfs_revalidate_inode(server, inode);
177}
178
179static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
180{
Andi Kleen9465efc2008-06-27 11:05:24 +0200181 loff_t loff;
Trond Myklebuste89e8962008-07-15 18:34:16 -0400182
Chuck Lever6da24bc2008-06-11 17:55:58 -0400183 dprintk("NFS: llseek file(%s/%s, %lld, %d)\n",
Chuck Leverb84e06c2008-06-11 17:55:34 -0400184 filp->f_path.dentry->d_parent->d_name.name,
185 filp->f_path.dentry->d_name.name,
186 offset, origin);
187
Trond Myklebust980802e2005-06-13 11:14:01 -0400188 /* origin == SEEK_END => we must revalidate the cached file length */
Josef 'Jeff' Sipekaec5e172006-09-16 21:09:32 -0400189 if (origin == SEEK_END) {
Trond Myklebust980802e2005-06-13 11:14:01 -0400190 struct inode *inode = filp->f_mapping->host;
Trond Myklebustd5e66342008-09-23 17:28:35 -0400191
Trond Myklebust980802e2005-06-13 11:14:01 -0400192 int retval = nfs_revalidate_file_size(inode, filp);
193 if (retval < 0)
194 return (loff_t)retval;
Trond Myklebustd5e66342008-09-23 17:28:35 -0400195
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);
Andi Kleen9465efc2008-06-27 11:05:24 +0200201 return loff;
Trond Myklebust980802e2005-06-13 11:14:01 -0400202}
203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204/*
Chuck Lever54917782008-05-27 16:29:07 -0400205 * Helper for nfs_file_flush() and nfs_file_fsync()
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400206 *
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 */
214static 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/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 * Flush all dirty pages, and check for write errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 */
232static int
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700233nfs_file_flush(struct file *file, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234{
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400235 struct nfs_open_context *ctx = nfs_file_open_context(file);
Chuck Lever6da24bc2008-06-11 17:55:58 -0400236 struct dentry *dentry = file->f_path.dentry;
237 struct inode *inode = dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 int status;
239
Chuck Lever6da24bc2008-06-11 17:55:58 -0400240 dprintk("NFS: flush(%s/%s)\n",
241 dentry->d_parent->d_name.name,
242 dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244 if ((file->f_mode & FMODE_WRITE) == 0)
245 return 0;
Chuck Lever91d5b472006-03-20 13:44:14 -0500246 nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 /* Ensure that data+attribute caches are up to date after close() */
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400249 status = nfs_do_fsync(ctx, inode);
250 if (!status)
251 nfs_revalidate_inode(NFS_SERVER(inode), inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 return status;
253}
254
255static ssize_t
Badari Pulavarty027445c2006-09-30 23:28:46 -0700256nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
257 unsigned long nr_segs, loff_t pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258{
Josef "Jeff" Sipek01cce932006-12-08 02:36:40 -0800259 struct dentry * dentry = iocb->ki_filp->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 struct inode * inode = dentry->d_inode;
261 ssize_t result;
Badari Pulavarty027445c2006-09-30 23:28:46 -0700262 size_t count = iov_length(iov, nr_segs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 if (iocb->ki_filp->f_flags & O_DIRECT)
Badari Pulavarty027445c2006-09-30 23:28:46 -0700265 return nfs_file_direct_read(iocb, iov, nr_segs, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
Chuck Lever6da24bc2008-06-11 17:55:58 -0400267 dprintk("NFS: read(%s/%s, %lu@%lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 dentry->d_parent->d_name.name, dentry->d_name.name,
269 (unsigned long) count, (unsigned long) pos);
270
Trond Myklebust44b11872006-05-25 01:40:59 -0400271 result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
Chuck Lever91d5b472006-03-20 13:44:14 -0500272 nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 if (!result)
Badari Pulavarty027445c2006-09-30 23:28:46 -0700274 result = generic_file_aio_read(iocb, iov, nr_segs, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 return result;
276}
277
278static ssize_t
Jens Axboef0930ff2007-06-01 11:51:43 +0200279nfs_file_splice_read(struct file *filp, loff_t *ppos,
280 struct pipe_inode_info *pipe, size_t count,
281 unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282{
Josef "Jeff" Sipek01cce932006-12-08 02:36:40 -0800283 struct dentry *dentry = filp->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 struct inode *inode = dentry->d_inode;
285 ssize_t res;
286
Chuck Lever6da24bc2008-06-11 17:55:58 -0400287 dprintk("NFS: splice_read(%s/%s, %lu@%Lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 dentry->d_parent->d_name.name, dentry->d_name.name,
289 (unsigned long) count, (unsigned long long) *ppos);
290
Trond Myklebust44b11872006-05-25 01:40:59 -0400291 res = nfs_revalidate_mapping(inode, filp->f_mapping);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 if (!res)
Jens Axboef0930ff2007-06-01 11:51:43 +0200293 res = generic_file_splice_read(filp, ppos, pipe, count, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 return res;
295}
296
297static int
298nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
299{
Josef "Jeff" Sipek01cce932006-12-08 02:36:40 -0800300 struct dentry *dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 struct inode *inode = dentry->d_inode;
302 int status;
303
Chuck Lever6da24bc2008-06-11 17:55:58 -0400304 dprintk("NFS: mmap(%s/%s)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 dentry->d_parent->d_name.name, dentry->d_name.name);
306
Trond Myklebust44b11872006-05-25 01:40:59 -0400307 status = nfs_revalidate_mapping(inode, file->f_mapping);
Trond Myklebust94387fb2007-07-22 17:09:05 -0400308 if (!status) {
309 vma->vm_ops = &nfs_file_vm_ops;
310 vma->vm_flags |= VM_CAN_NONLINEAR;
311 file_accessed(file);
312 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 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 */
321static int
Chuck Lever54917782008-05-27 16:29:07 -0400322nfs_file_fsync(struct file *file, struct dentry *dentry, int datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323{
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400324 struct nfs_open_context *ctx = nfs_file_open_context(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 struct inode *inode = dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326
Chuck Lever6da24bc2008-06-11 17:55:58 -0400327 dprintk("NFS: fsync file(%s/%s) datasync %d\n",
Chuck Lever54917782008-05-27 16:29:07 -0400328 dentry->d_parent->d_name.name, dentry->d_name.name,
329 datasync);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330
Chuck Lever91d5b472006-03-20 13:44:14 -0500331 nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400332 return nfs_do_fsync(ctx, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333}
334
335/*
Nick Piggin4899f9c2007-10-16 01:25:16 -0700336 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 *
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 */
Nick Piggin4899f9c2007-10-16 01:25:16 -0700343static 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)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346{
Nick Piggin4899f9c2007-10-16 01:25:16 -0700347 int ret;
348 pgoff_t index;
349 struct page *page;
350 index = pos >> PAGE_CACHE_SHIFT;
351
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400352 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
Nick Piggin54566b22009-01-04 12:00:53 -0800357 page = grab_cache_page_write_begin(mapping, index, flags);
Nick Piggin4899f9c2007-10-16 01:25:16 -0700358 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368}
369
Nick Piggin4899f9c2007-10-16 01:25:16 -0700370static 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)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373{
Nick Piggin4899f9c2007-10-16 01:25:16 -0700374 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
375 int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400377 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
Trond Myklebustefc91ed2008-06-10 18:31:00 -0400382 /*
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
Nick Piggin4899f9c2007-10-16 01:25:16 -0700402 status = nfs_updatepage(file, page, offset, copied);
Nick Piggin4899f9c2007-10-16 01:25:16 -0700403
404 unlock_page(page);
405 page_cache_release(page);
406
Chuck Lever3d509e52007-12-20 14:55:04 -0500407 if (status < 0)
408 return status;
409 return copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410}
411
NeilBrown2ff28e22006-03-26 01:37:18 -0800412static void nfs_invalidate_page(struct page *page, unsigned long offset)
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500413{
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400414 dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset);
415
Trond Myklebust1c759502006-10-09 16:18:38 -0400416 if (offset != 0)
417 return;
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400418 /* Cancel any unstarted writes on this page */
Trond Myklebust1b3b4a12007-08-28 10:29:36 -0400419 nfs_wb_page_cancel(page->mapping->host, page);
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500420}
421
422static int nfs_release_page(struct page *page, gfp_t gfp)
423{
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400424 dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
425
Trond Myklebuste3db7692007-01-10 23:15:39 -0800426 /* If PagePrivate() is set, then the page is not freeable */
427 return 0;
428}
429
430static int nfs_launder_page(struct page *page)
431{
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400432 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);
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500438}
439
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700440const struct address_space_operations nfs_file_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 .readpage = nfs_readpage,
442 .readpages = nfs_readpages,
Trond Myklebust9cccef92007-07-22 17:09:05 -0400443 .set_page_dirty = __set_page_dirty_nobuffers,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 .writepage = nfs_writepage,
445 .writepages = nfs_writepages,
Nick Piggin4899f9c2007-10-16 01:25:16 -0700446 .write_begin = nfs_write_begin,
447 .write_end = nfs_write_end,
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500448 .invalidatepage = nfs_invalidate_page,
449 .releasepage = nfs_release_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 .direct_IO = nfs_direct_IO,
Trond Myklebuste3db7692007-01-10 23:15:39 -0800451 .launder_page = nfs_launder_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452};
453
Trond Myklebust94387fb2007-07-22 17:09:05 -0400454static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
455{
456 struct file *filp = vma->vm_file;
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400457 struct dentry *dentry = filp->f_path.dentry;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400458 unsigned pagelen;
459 int ret = -EINVAL;
Nick Piggin4899f9c2007-10-16 01:25:16 -0700460 struct address_space *mapping;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400461
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400462 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
Trond Myklebust94387fb2007-07-22 17:09:05 -0400467 lock_page(page);
Nick Piggin4899f9c2007-10-16 01:25:16 -0700468 mapping = page->mapping;
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400469 if (mapping != dentry->d_inode->i_mapping)
Trond Myklebust8b1f9ee2008-01-22 17:13:06 -0500470 goto out_unlock;
471
472 ret = 0;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400473 pagelen = nfs_page_length(page);
Trond Myklebust8b1f9ee2008-01-22 17:13:06 -0500474 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;
484out_unlock:
Trond Myklebust94387fb2007-07-22 17:09:05 -0400485 unlock_page(page);
486 return ret;
487}
488
489static struct vm_operations_struct nfs_file_vm_ops = {
490 .fault = filemap_fault,
491 .page_mkwrite = nfs_vm_page_mkwrite,
492};
493
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400494static 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;
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400500 ctx = nfs_file_open_context(filp);
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400501 if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags))
502 return 1;
503 return 0;
504}
505
Badari Pulavarty027445c2006-09-30 23:28:46 -0700506static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
507 unsigned long nr_segs, loff_t pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508{
Josef "Jeff" Sipek01cce932006-12-08 02:36:40 -0800509 struct dentry * dentry = iocb->ki_filp->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 struct inode * inode = dentry->d_inode;
511 ssize_t result;
Badari Pulavarty027445c2006-09-30 23:28:46 -0700512 size_t count = iov_length(iov, nr_segs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 if (iocb->ki_filp->f_flags & O_DIRECT)
Badari Pulavarty027445c2006-09-30 23:28:46 -0700515 return nfs_file_direct_write(iocb, iov, nr_segs, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
Chuck Lever6da24bc2008-06-11 17:55:58 -0400517 dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 dentry->d_parent->d_name.name, dentry->d_name.name,
Chuck Lever6da24bc2008-06-11 17:55:58 -0400519 (unsigned long) count, (long long) pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
521 result = -EBUSY;
522 if (IS_SWAPFILE(inode))
523 goto out_swapfile;
Trond Myklebust7d52e862005-06-22 17:16:30 +0000524 /*
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;
Trond Myklebustfe51bee2005-06-22 17:16:30 +0000531 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532
533 result = count;
534 if (!count)
535 goto out;
536
Chuck Lever91d5b472006-03-20 13:44:14 -0500537 nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
Badari Pulavarty027445c2006-09-30 23:28:46 -0700538 result = generic_file_aio_write(iocb, iov, nr_segs, pos);
Trond Myklebust200baa22006-12-05 00:35:40 -0500539 /* Return error values for O_SYNC and IS_SYNC() */
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400540 if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) {
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400541 int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode);
Trond Myklebust200baa22006-12-05 00:35:40 -0500542 if (err < 0)
543 result = err;
544 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545out:
546 return result;
547
548out_swapfile:
549 printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
550 goto out;
551}
552
553static 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();
Trond Myklebust039c4d72005-10-18 14:20:16 -0700559 /* Try local locking first */
J. Bruce Fields6d34ac12007-05-11 16:09:32 -0400560 posix_test_lock(filp, fl);
561 if (fl->fl_type != F_UNLCK) {
562 /* found a conflict */
Trond Myklebust039c4d72005-10-18 14:20:16 -0700563 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 }
Trond Myklebust039c4d72005-10-18 14:20:16 -0700565
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);
573out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 unlock_kernel();
575 return status;
Trond Myklebust039c4d72005-10-18 14:20:16 -0700576out_noconflict:
577 fl->fl_type = F_UNLCK;
578 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579}
580
581static 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)
Neil Brown46bae1a2007-01-30 14:36:01 -0800595 dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager"
596 " - error %d!\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700597 __func__, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 return res;
599}
600
601static int do_unlk(struct file *filp, int cmd, struct file_lock *fl)
602{
603 struct inode *inode = filp->f_mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 int status;
605
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 /*
607 * Flush all pending writes before doing anything
608 * with locks..
609 */
Trond Myklebust29884df2005-12-13 16:13:54 -0500610 nfs_sync_mapping(filp->f_mapping);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
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();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 return status;
624}
625
626static int do_setlk(struct file *filp, int cmd, struct file_lock *fl)
627{
628 struct inode *inode = filp->f_mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 int status;
630
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 /*
632 * Flush all pending writes before doing anything
633 * with locks..
634 */
Trond Myklebust29884df2005-12-13 16:13:54 -0500635 status = nfs_sync_mapping(filp->f_mapping);
636 if (status != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 goto out;
638
639 lock_kernel();
640 /* Use local locking if mounted with "-onolock" */
Trond Myklebustc4d7c402008-04-01 20:26:52 -0400641 if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
Trond Myklebustc4d7c402008-04-01 20:26:52 -0400643 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 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 */
Trond Myklebust29884df2005-12-13 16:13:54 -0500652 nfs_sync_mapping(filp->f_mapping);
Trond Myklebustb5418382008-06-10 18:31:02 -0400653 if (!nfs_have_delegation(inode, FMODE_READ))
654 nfs_zap_caches(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 return status;
657}
658
659/*
660 * Lock a (portion of) a file
661 */
662static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
663{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400664 struct inode *inode = filp->f_mapping->host;
Trond Myklebust21162712008-05-20 19:34:39 -0400665 int ret = -ENOLCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666
Chuck Lever6da24bc2008-06-11 17:55:58 -0400667 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,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 fl->fl_type, fl->fl_flags,
671 (long long)fl->fl_start, (long long)fl->fl_end);
Chuck Lever6da24bc2008-06-11 17:55:58 -0400672
Chuck Lever91d5b472006-03-20 13:44:14 -0500673 nfs_inc_stats(inode, NFSIOS_VFSLOCK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674
675 /* No mandatory locks over NFS */
Pavel Emelyanovdfad9442007-10-01 14:41:15 -0700676 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
Trond Myklebust21162712008-05-20 19:34:39 -0400677 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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
685 if (IS_GETLK(cmd))
Trond Myklebust21162712008-05-20 19:34:39 -0400686 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);
691out_err:
692 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693}
694
695/*
696 * Lock a (portion of) a file
697 */
698static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
699{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400700 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,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 fl->fl_type, fl->fl_flags);
704
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 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}
J. Bruce Fields370f6592007-06-08 15:23:34 -0400717
Chuck Lever6da24bc2008-06-11 17:55:58 -0400718/*
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 */
J. Bruce Fields370f6592007-06-08 15:23:34 -0400722static int nfs_setlease(struct file *file, long arg, struct file_lock **fl)
723{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400724 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
J. Bruce Fields370f6592007-06-08 15:23:34 -0400728 return -EINVAL;
729}