blob: 78b26f875eee9fb69678ccfd0ef745d7959ede43 [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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 lock_kernel();
David Howells1f163412006-08-22 20:06:11 -0400132 res = NFS_PROTO(inode)->file_open(inode, filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 unlock_kernel();
134 return res;
135}
136
137static int
138nfs_file_release(struct inode *inode, struct file *filp)
139{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400140 struct dentry *dentry = filp->f_path.dentry;
141
142 dprintk("NFS: release(%s/%s)\n",
143 dentry->d_parent->d_name.name,
144 dentry->d_name.name);
145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 /* Ensure that dirty pages are flushed out with the right creds */
147 if (filp->f_mode & FMODE_WRITE)
Chuck Lever6da24bc2008-06-11 17:55:58 -0400148 nfs_wb_all(dentry->d_inode);
Chuck Lever91d5b472006-03-20 13:44:14 -0500149 nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 return NFS_PROTO(inode)->file_release(inode, filp);
151}
152
Trond Myklebust980802e2005-06-13 11:14:01 -0400153/**
154 * nfs_revalidate_size - Revalidate the file size
155 * @inode - pointer to inode struct
156 * @file - pointer to struct file
157 *
158 * Revalidates the file length. This is basically a wrapper around
159 * nfs_revalidate_inode() that takes into account the fact that we may
160 * have cached writes (in which case we don't care about the server's
161 * idea of what the file length is), or O_DIRECT (in which case we
162 * shouldn't trust the cache).
163 */
164static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
165{
166 struct nfs_server *server = NFS_SERVER(inode);
167 struct nfs_inode *nfsi = NFS_I(inode);
168
169 if (server->flags & NFS_MOUNT_NOAC)
170 goto force_reval;
171 if (filp->f_flags & O_DIRECT)
172 goto force_reval;
173 if (nfsi->npages != 0)
174 return 0;
Chuck Lever55296802005-08-18 11:24:09 -0700175 if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode))
Trond Myklebustfe51beec2005-06-22 17:16:30 +0000176 return 0;
Trond Myklebust980802e2005-06-13 11:14:01 -0400177force_reval:
178 return __nfs_revalidate_inode(server, inode);
179}
180
181static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
182{
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;
191 int retval = nfs_revalidate_file_size(inode, filp);
192 if (retval < 0)
193 return (loff_t)retval;
194 }
195 return remote_llseek(filp, offset, origin);
196}
197
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198/*
Chuck Lever54917782008-05-27 16:29:07 -0400199 * Helper for nfs_file_flush() and nfs_file_fsync()
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400200 *
201 * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
202 * disk, but it retrieves and clears ctx->error after synching, despite
203 * the two being set at the same time in nfs_context_set_write_error().
204 * This is because the former is used to notify the _next_ call to
205 * nfs_file_write() that a write error occured, and hence cause it to
206 * fall back to doing a synchronous write.
207 */
208static int nfs_do_fsync(struct nfs_open_context *ctx, struct inode *inode)
209{
210 int have_error, status;
211 int ret = 0;
212
213 have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
214 status = nfs_wb_all(inode);
215 have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
216 if (have_error)
217 ret = xchg(&ctx->error, 0);
218 if (!ret)
219 ret = status;
220 return ret;
221}
222
223/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 * Flush all dirty pages, and check for write errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 */
226static int
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700227nfs_file_flush(struct file *file, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228{
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400229 struct nfs_open_context *ctx = nfs_file_open_context(file);
Chuck Lever6da24bc2008-06-11 17:55:58 -0400230 struct dentry *dentry = file->f_path.dentry;
231 struct inode *inode = dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 int status;
233
Chuck Lever6da24bc2008-06-11 17:55:58 -0400234 dprintk("NFS: flush(%s/%s)\n",
235 dentry->d_parent->d_name.name,
236 dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238 if ((file->f_mode & FMODE_WRITE) == 0)
239 return 0;
Chuck Lever91d5b472006-03-20 13:44:14 -0500240 nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 /* Ensure that data+attribute caches are up to date after close() */
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400243 status = nfs_do_fsync(ctx, inode);
244 if (!status)
245 nfs_revalidate_inode(NFS_SERVER(inode), inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 return status;
247}
248
249static ssize_t
Badari Pulavarty027445c2006-09-30 23:28:46 -0700250nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
251 unsigned long nr_segs, loff_t pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252{
Josef "Jeff" Sipek01cce932006-12-08 02:36:40 -0800253 struct dentry * dentry = iocb->ki_filp->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 struct inode * inode = dentry->d_inode;
255 ssize_t result;
Badari Pulavarty027445c2006-09-30 23:28:46 -0700256 size_t count = iov_length(iov, nr_segs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 if (iocb->ki_filp->f_flags & O_DIRECT)
Badari Pulavarty027445c2006-09-30 23:28:46 -0700259 return nfs_file_direct_read(iocb, iov, nr_segs, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
Chuck Lever6da24bc2008-06-11 17:55:58 -0400261 dprintk("NFS: read(%s/%s, %lu@%lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 dentry->d_parent->d_name.name, dentry->d_name.name,
263 (unsigned long) count, (unsigned long) pos);
264
Trond Myklebust44b11872006-05-25 01:40:59 -0400265 result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
Chuck Lever91d5b472006-03-20 13:44:14 -0500266 nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 if (!result)
Badari Pulavarty027445c2006-09-30 23:28:46 -0700268 result = generic_file_aio_read(iocb, iov, nr_segs, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 return result;
270}
271
272static ssize_t
Jens Axboef0930ff2007-06-01 11:51:43 +0200273nfs_file_splice_read(struct file *filp, loff_t *ppos,
274 struct pipe_inode_info *pipe, size_t count,
275 unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
Josef "Jeff" Sipek01cce932006-12-08 02:36:40 -0800277 struct dentry *dentry = filp->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 struct inode *inode = dentry->d_inode;
279 ssize_t res;
280
Chuck Lever6da24bc2008-06-11 17:55:58 -0400281 dprintk("NFS: splice_read(%s/%s, %lu@%Lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 dentry->d_parent->d_name.name, dentry->d_name.name,
283 (unsigned long) count, (unsigned long long) *ppos);
284
Trond Myklebust44b11872006-05-25 01:40:59 -0400285 res = nfs_revalidate_mapping(inode, filp->f_mapping);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 if (!res)
Jens Axboef0930ff2007-06-01 11:51:43 +0200287 res = generic_file_splice_read(filp, ppos, pipe, count, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 return res;
289}
290
291static int
292nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
293{
Josef "Jeff" Sipek01cce932006-12-08 02:36:40 -0800294 struct dentry *dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 struct inode *inode = dentry->d_inode;
296 int status;
297
Chuck Lever6da24bc2008-06-11 17:55:58 -0400298 dprintk("NFS: mmap(%s/%s)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 dentry->d_parent->d_name.name, dentry->d_name.name);
300
Trond Myklebust44b11872006-05-25 01:40:59 -0400301 status = nfs_revalidate_mapping(inode, file->f_mapping);
Trond Myklebust94387fb2007-07-22 17:09:05 -0400302 if (!status) {
303 vma->vm_ops = &nfs_file_vm_ops;
304 vma->vm_flags |= VM_CAN_NONLINEAR;
305 file_accessed(file);
306 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 return status;
308}
309
310/*
311 * Flush any dirty pages for this process, and check for write errors.
312 * The return status from this call provides a reliable indication of
313 * whether any write errors occurred for this process.
314 */
315static int
Chuck Lever54917782008-05-27 16:29:07 -0400316nfs_file_fsync(struct file *file, struct dentry *dentry, int datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317{
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400318 struct nfs_open_context *ctx = nfs_file_open_context(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 struct inode *inode = dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320
Chuck Lever6da24bc2008-06-11 17:55:58 -0400321 dprintk("NFS: fsync file(%s/%s) datasync %d\n",
Chuck Lever54917782008-05-27 16:29:07 -0400322 dentry->d_parent->d_name.name, dentry->d_name.name,
323 datasync);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324
Chuck Lever91d5b472006-03-20 13:44:14 -0500325 nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400326 return nfs_do_fsync(ctx, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327}
328
329/*
Nick Piggin4899f9c2007-10-16 01:25:16 -0700330 * This does the "real" work of the write. We must allocate and lock the
331 * page to be sent back to the generic routine, which then copies the
332 * data from user space.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 *
334 * If the writer ends up delaying the write, the writer needs to
335 * increment the page use counts until he is done with the page.
336 */
Nick Piggin4899f9c2007-10-16 01:25:16 -0700337static int nfs_write_begin(struct file *file, struct address_space *mapping,
338 loff_t pos, unsigned len, unsigned flags,
339 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340{
Nick Piggin4899f9c2007-10-16 01:25:16 -0700341 int ret;
342 pgoff_t index;
343 struct page *page;
344 index = pos >> PAGE_CACHE_SHIFT;
345
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400346 dfprintk(PAGECACHE, "NFS: write_begin(%s/%s(%ld), %u@%lld)\n",
347 file->f_path.dentry->d_parent->d_name.name,
348 file->f_path.dentry->d_name.name,
349 mapping->host->i_ino, len, (long long) pos);
350
Nick Piggin4899f9c2007-10-16 01:25:16 -0700351 page = __grab_cache_page(mapping, index);
352 if (!page)
353 return -ENOMEM;
354 *pagep = page;
355
356 ret = nfs_flush_incompatible(file, page);
357 if (ret) {
358 unlock_page(page);
359 page_cache_release(page);
360 }
361 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362}
363
Nick Piggin4899f9c2007-10-16 01:25:16 -0700364static int nfs_write_end(struct file *file, struct address_space *mapping,
365 loff_t pos, unsigned len, unsigned copied,
366 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367{
Nick Piggin4899f9c2007-10-16 01:25:16 -0700368 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
369 int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400371 dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n",
372 file->f_path.dentry->d_parent->d_name.name,
373 file->f_path.dentry->d_name.name,
374 mapping->host->i_ino, len, (long long) pos);
375
Trond Myklebustefc91ed2008-06-10 18:31:00 -0400376 /*
377 * Zero any uninitialised parts of the page, and then mark the page
378 * as up to date if it turns out that we're extending the file.
379 */
380 if (!PageUptodate(page)) {
381 unsigned pglen = nfs_page_length(page);
382 unsigned end = offset + len;
383
384 if (pglen == 0) {
385 zero_user_segments(page, 0, offset,
386 end, PAGE_CACHE_SIZE);
387 SetPageUptodate(page);
388 } else if (end >= pglen) {
389 zero_user_segment(page, end, PAGE_CACHE_SIZE);
390 if (offset == 0)
391 SetPageUptodate(page);
392 } else
393 zero_user_segment(page, pglen, PAGE_CACHE_SIZE);
394 }
395
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 lock_kernel();
Nick Piggin4899f9c2007-10-16 01:25:16 -0700397 status = nfs_updatepage(file, page, offset, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 unlock_kernel();
Nick Piggin4899f9c2007-10-16 01:25:16 -0700399
400 unlock_page(page);
401 page_cache_release(page);
402
Chuck Lever3d509e52007-12-20 14:55:04 -0500403 if (status < 0)
404 return status;
405 return copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406}
407
NeilBrown2ff28e22006-03-26 01:37:18 -0800408static void nfs_invalidate_page(struct page *page, unsigned long offset)
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500409{
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400410 dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset);
411
Trond Myklebust1c759502006-10-09 16:18:38 -0400412 if (offset != 0)
413 return;
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400414 /* Cancel any unstarted writes on this page */
Trond Myklebust1b3b4a12007-08-28 10:29:36 -0400415 nfs_wb_page_cancel(page->mapping->host, page);
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500416}
417
418static int nfs_release_page(struct page *page, gfp_t gfp)
419{
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400420 dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
421
Trond Myklebuste3db7692007-01-10 23:15:39 -0800422 /* If PagePrivate() is set, then the page is not freeable */
423 return 0;
424}
425
426static int nfs_launder_page(struct page *page)
427{
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400428 struct inode *inode = page->mapping->host;
429
430 dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
431 inode->i_ino, (long long)page_offset(page));
432
433 return nfs_wb_page(inode, page);
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500434}
435
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700436const struct address_space_operations nfs_file_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 .readpage = nfs_readpage,
438 .readpages = nfs_readpages,
Trond Myklebust9cccef92007-07-22 17:09:05 -0400439 .set_page_dirty = __set_page_dirty_nobuffers,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 .writepage = nfs_writepage,
441 .writepages = nfs_writepages,
Nick Piggin4899f9c2007-10-16 01:25:16 -0700442 .write_begin = nfs_write_begin,
443 .write_end = nfs_write_end,
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500444 .invalidatepage = nfs_invalidate_page,
445 .releasepage = nfs_release_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 .direct_IO = nfs_direct_IO,
Trond Myklebuste3db7692007-01-10 23:15:39 -0800447 .launder_page = nfs_launder_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448};
449
Trond Myklebust94387fb2007-07-22 17:09:05 -0400450static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
451{
452 struct file *filp = vma->vm_file;
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400453 struct dentry *dentry = filp->f_path.dentry;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400454 unsigned pagelen;
455 int ret = -EINVAL;
Nick Piggin4899f9c2007-10-16 01:25:16 -0700456 struct address_space *mapping;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400457
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400458 dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n",
459 dentry->d_parent->d_name.name, dentry->d_name.name,
460 filp->f_mapping->host->i_ino,
461 (long long)page_offset(page));
462
Trond Myklebust94387fb2007-07-22 17:09:05 -0400463 lock_page(page);
Nick Piggin4899f9c2007-10-16 01:25:16 -0700464 mapping = page->mapping;
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400465 if (mapping != dentry->d_inode->i_mapping)
Trond Myklebust8b1f9ee2008-01-22 17:13:06 -0500466 goto out_unlock;
467
468 ret = 0;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400469 pagelen = nfs_page_length(page);
Trond Myklebust8b1f9ee2008-01-22 17:13:06 -0500470 if (pagelen == 0)
471 goto out_unlock;
472
473 ret = nfs_flush_incompatible(filp, page);
474 if (ret != 0)
475 goto out_unlock;
476
477 ret = nfs_updatepage(filp, page, 0, pagelen);
478 if (ret == 0)
479 ret = pagelen;
480out_unlock:
Trond Myklebust94387fb2007-07-22 17:09:05 -0400481 unlock_page(page);
482 return ret;
483}
484
485static struct vm_operations_struct nfs_file_vm_ops = {
486 .fault = filemap_fault,
487 .page_mkwrite = nfs_vm_page_mkwrite,
488};
489
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400490static int nfs_need_sync_write(struct file *filp, struct inode *inode)
491{
492 struct nfs_open_context *ctx;
493
494 if (IS_SYNC(inode) || (filp->f_flags & O_SYNC))
495 return 1;
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400496 ctx = nfs_file_open_context(filp);
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400497 if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags))
498 return 1;
499 return 0;
500}
501
Badari Pulavarty027445c2006-09-30 23:28:46 -0700502static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
503 unsigned long nr_segs, loff_t pos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504{
Josef "Jeff" Sipek01cce932006-12-08 02:36:40 -0800505 struct dentry * dentry = iocb->ki_filp->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 struct inode * inode = dentry->d_inode;
507 ssize_t result;
Badari Pulavarty027445c2006-09-30 23:28:46 -0700508 size_t count = iov_length(iov, nr_segs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 if (iocb->ki_filp->f_flags & O_DIRECT)
Badari Pulavarty027445c2006-09-30 23:28:46 -0700511 return nfs_file_direct_write(iocb, iov, nr_segs, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
Chuck Lever6da24bc2008-06-11 17:55:58 -0400513 dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 dentry->d_parent->d_name.name, dentry->d_name.name,
Chuck Lever6da24bc2008-06-11 17:55:58 -0400515 (unsigned long) count, (long long) pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517 result = -EBUSY;
518 if (IS_SWAPFILE(inode))
519 goto out_swapfile;
Trond Myklebust7d52e862005-06-22 17:16:30 +0000520 /*
521 * O_APPEND implies that we must revalidate the file length.
522 */
523 if (iocb->ki_filp->f_flags & O_APPEND) {
524 result = nfs_revalidate_file_size(inode, iocb->ki_filp);
525 if (result)
526 goto out;
Trond Myklebustfe51beec2005-06-22 17:16:30 +0000527 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
529 result = count;
530 if (!count)
531 goto out;
532
Chuck Lever91d5b472006-03-20 13:44:14 -0500533 nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
Badari Pulavarty027445c2006-09-30 23:28:46 -0700534 result = generic_file_aio_write(iocb, iov, nr_segs, pos);
Trond Myklebust200baa22006-12-05 00:35:40 -0500535 /* Return error values for O_SYNC and IS_SYNC() */
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400536 if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) {
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400537 int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode);
Trond Myklebust200baa22006-12-05 00:35:40 -0500538 if (err < 0)
539 result = err;
540 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541out:
542 return result;
543
544out_swapfile:
545 printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
546 goto out;
547}
548
549static int do_getlk(struct file *filp, int cmd, struct file_lock *fl)
550{
551 struct inode *inode = filp->f_mapping->host;
552 int status = 0;
553
554 lock_kernel();
Trond Myklebust039c4d72005-10-18 14:20:16 -0700555 /* Try local locking first */
J. Bruce Fields6d34ac12007-05-11 16:09:32 -0400556 posix_test_lock(filp, fl);
557 if (fl->fl_type != F_UNLCK) {
558 /* found a conflict */
Trond Myklebust039c4d72005-10-18 14:20:16 -0700559 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 }
Trond Myklebust039c4d72005-10-18 14:20:16 -0700561
562 if (nfs_have_delegation(inode, FMODE_READ))
563 goto out_noconflict;
564
565 if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)
566 goto out_noconflict;
567
568 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
569out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 unlock_kernel();
571 return status;
Trond Myklebust039c4d72005-10-18 14:20:16 -0700572out_noconflict:
573 fl->fl_type = F_UNLCK;
574 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575}
576
577static int do_vfs_lock(struct file *file, struct file_lock *fl)
578{
579 int res = 0;
580 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
581 case FL_POSIX:
582 res = posix_lock_file_wait(file, fl);
583 break;
584 case FL_FLOCK:
585 res = flock_lock_file_wait(file, fl);
586 break;
587 default:
588 BUG();
589 }
590 if (res < 0)
Neil Brown46bae1a2007-01-30 14:36:01 -0800591 dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager"
592 " - error %d!\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700593 __func__, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 return res;
595}
596
597static int do_unlk(struct file *filp, int cmd, struct file_lock *fl)
598{
599 struct inode *inode = filp->f_mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 int status;
601
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 /*
603 * Flush all pending writes before doing anything
604 * with locks..
605 */
Trond Myklebust29884df2005-12-13 16:13:54 -0500606 nfs_sync_mapping(filp->f_mapping);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
608 /* NOTE: special case
609 * If we're signalled while cleaning up locks on process exit, we
610 * still need to complete the unlock.
611 */
612 lock_kernel();
613 /* Use local locking if mounted with "-onolock" */
614 if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
615 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
616 else
617 status = do_vfs_lock(filp, fl);
618 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 return status;
620}
621
622static int do_setlk(struct file *filp, int cmd, struct file_lock *fl)
623{
624 struct inode *inode = filp->f_mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 int status;
626
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 /*
628 * Flush all pending writes before doing anything
629 * with locks..
630 */
Trond Myklebust29884df2005-12-13 16:13:54 -0500631 status = nfs_sync_mapping(filp->f_mapping);
632 if (status != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 goto out;
634
635 lock_kernel();
636 /* Use local locking if mounted with "-onolock" */
Trond Myklebustc4d7c402008-04-01 20:26:52 -0400637 if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
Trond Myklebustc4d7c402008-04-01 20:26:52 -0400639 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 status = do_vfs_lock(filp, fl);
641 unlock_kernel();
642 if (status < 0)
643 goto out;
644 /*
645 * Make sure we clear the cache whenever we try to get the lock.
646 * This makes locking act as a cache coherency point.
647 */
Trond Myklebust29884df2005-12-13 16:13:54 -0500648 nfs_sync_mapping(filp->f_mapping);
Trond Myklebustb5418382008-06-10 18:31:02 -0400649 if (!nfs_have_delegation(inode, FMODE_READ))
650 nfs_zap_caches(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 return status;
653}
654
655/*
656 * Lock a (portion of) a file
657 */
658static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
659{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400660 struct inode *inode = filp->f_mapping->host;
Trond Myklebust21162712008-05-20 19:34:39 -0400661 int ret = -ENOLCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662
Chuck Lever6da24bc2008-06-11 17:55:58 -0400663 dprintk("NFS: lock(%s/%s, t=%x, fl=%x, r=%lld:%lld)\n",
664 filp->f_path.dentry->d_parent->d_name.name,
665 filp->f_path.dentry->d_name.name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 fl->fl_type, fl->fl_flags,
667 (long long)fl->fl_start, (long long)fl->fl_end);
Chuck Lever6da24bc2008-06-11 17:55:58 -0400668
Chuck Lever91d5b472006-03-20 13:44:14 -0500669 nfs_inc_stats(inode, NFSIOS_VFSLOCK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
671 /* No mandatory locks over NFS */
Pavel Emelyanovdfad9442007-10-01 14:41:15 -0700672 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
Trond Myklebust21162712008-05-20 19:34:39 -0400673 goto out_err;
674
675 if (NFS_PROTO(inode)->lock_check_bounds != NULL) {
676 ret = NFS_PROTO(inode)->lock_check_bounds(fl);
677 if (ret < 0)
678 goto out_err;
679 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
681 if (IS_GETLK(cmd))
Trond Myklebust21162712008-05-20 19:34:39 -0400682 ret = do_getlk(filp, cmd, fl);
683 else if (fl->fl_type == F_UNLCK)
684 ret = do_unlk(filp, cmd, fl);
685 else
686 ret = do_setlk(filp, cmd, fl);
687out_err:
688 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689}
690
691/*
692 * Lock a (portion of) a file
693 */
694static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
695{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400696 dprintk("NFS: flock(%s/%s, t=%x, fl=%x)\n",
697 filp->f_path.dentry->d_parent->d_name.name,
698 filp->f_path.dentry->d_name.name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 fl->fl_type, fl->fl_flags);
700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 /*
702 * No BSD flocks over NFS allowed.
703 * Note: we could try to fake a POSIX lock request here by
704 * using ((u32) filp | 0x80000000) or some such as the pid.
705 * Not sure whether that would be unique, though, or whether
706 * that would break in other places.
707 */
708 if (!(fl->fl_flags & FL_FLOCK))
709 return -ENOLCK;
710
711 /* We're simulating flock() locks using posix locks on the server */
712 fl->fl_owner = (fl_owner_t)filp;
713 fl->fl_start = 0;
714 fl->fl_end = OFFSET_MAX;
715
716 if (fl->fl_type == F_UNLCK)
717 return do_unlk(filp, cmd, fl);
718 return do_setlk(filp, cmd, fl);
719}
J. Bruce Fields370f6592007-06-08 15:23:34 -0400720
Chuck Lever6da24bc2008-06-11 17:55:58 -0400721/*
722 * There is no protocol support for leases, so we have no way to implement
723 * them correctly in the face of opens by other clients.
724 */
J. Bruce Fields370f6592007-06-08 15:23:34 -0400725static int nfs_setlease(struct file *file, long arg, struct file_lock **fl)
726{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400727 dprintk("NFS: setlease(%s/%s, arg=%ld)\n",
728 file->f_path.dentry->d_parent->d_name.name,
729 file->f_path.dentry->d_name.name, arg);
730
J. Bruce Fields370f6592007-06-08 15:23:34 -0400731 return -EINVAL;
732}