blob: 46cf0afe3c0fd7df5907259a75c09a7c936cc6f1 [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
Bryan Schumakerddda8e02012-07-30 16:05:23 -040019#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/time.h>
21#include <linux/kernel.h>
22#include <linux/errno.h>
23#include <linux/fcntl.h>
24#include <linux/stat.h>
25#include <linux/nfs_fs.h>
26#include <linux/nfs_mount.h>
27#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/pagemap.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/gfp.h>
Trond Myklebustb608b282010-07-30 15:31:54 -040030#include <linux/swap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32#include <asm/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#include "delegation.h"
Trond Myklebust94387fb2007-07-22 17:09:05 -040035#include "internal.h"
Chuck Lever91d5b472006-03-20 13:44:14 -050036#include "iostat.h"
David Howells545db452009-04-03 16:42:44 +010037#include "fscache.h"
Christoph Hellwig612aa982014-09-10 08:23:30 -070038#include "pnfs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Trond Myklebustf4ce1292013-08-19 18:59:33 -040040#include "nfstrace.h"
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#define NFSDBG_FACILITY NFSDBG_FILE
43
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +040044static const struct vm_operations_struct nfs_file_vm_ops;
Trond Myklebust94387fb2007-07-22 17:09:05 -040045
Linus Torvalds1da177e2005-04-16 15:20:36 -070046/* Hack for future NFS swap support */
47#ifndef IS_SWAPFILE
48# define IS_SWAPFILE(inode) (0)
49#endif
50
Bryan Schumakerce4ef7c2012-07-16 16:39:15 -040051int nfs_check_flags(int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
53 if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT))
54 return -EINVAL;
55
56 return 0;
57}
Bryan Schumaker89d77c82012-07-30 16:05:25 -040058EXPORT_SYMBOL_GPL(nfs_check_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60/*
61 * Open file
62 */
63static int
64nfs_file_open(struct inode *inode, struct file *filp)
65{
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 int res;
67
Al Viro6de14722013-09-16 10:53:17 -040068 dprintk("NFS: open file(%pD2)\n", filp);
Chuck Levercc0dd2d2008-06-11 17:55:42 -040069
Chuck Leverc2459dc2010-02-01 14:17:14 -050070 nfs_inc_stats(inode, NFSIOS_VFSOPEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 res = nfs_check_flags(filp->f_flags);
72 if (res)
73 return res;
74
Trond Myklebust46cb6502008-06-11 16:32:46 -040075 res = nfs_open(inode, filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 return res;
77}
78
Bryan Schumakerce4ef7c2012-07-16 16:39:15 -040079int
Linus Torvalds1da177e2005-04-16 15:20:36 -070080nfs_file_release(struct inode *inode, struct file *filp)
81{
Al Viro6de14722013-09-16 10:53:17 -040082 dprintk("NFS: release(%pD2)\n", filp);
Chuck Lever6da24bc2008-06-11 17:55:58 -040083
Chuck Lever91d5b472006-03-20 13:44:14 -050084 nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
Anna Schumakeraff8d8d2015-07-13 14:01:33 -040085 nfs_file_clear_open_context(filp);
86 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
Bryan Schumaker89d77c82012-07-30 16:05:25 -040088EXPORT_SYMBOL_GPL(nfs_file_release);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
Trond Myklebust980802e2005-06-13 11:14:01 -040090/**
91 * nfs_revalidate_size - Revalidate the file size
92 * @inode - pointer to inode struct
93 * @file - pointer to struct file
94 *
95 * Revalidates the file length. This is basically a wrapper around
96 * nfs_revalidate_inode() that takes into account the fact that we may
97 * have cached writes (in which case we don't care about the server's
98 * idea of what the file length is), or O_DIRECT (in which case we
99 * shouldn't trust the cache).
100 */
101static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
102{
103 struct nfs_server *server = NFS_SERVER(inode);
104 struct nfs_inode *nfsi = NFS_I(inode);
105
Trond Myklebustd7cf8dd2010-04-16 16:42:46 -0400106 if (nfs_have_delegated_attributes(inode))
107 goto out_noreval;
108
Trond Myklebust980802e2005-06-13 11:14:01 -0400109 if (filp->f_flags & O_DIRECT)
110 goto force_reval;
Trond Myklebustd7cf8dd2010-04-16 16:42:46 -0400111 if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
112 goto force_reval;
113 if (nfs_attribute_timeout(inode))
114 goto force_reval;
115out_noreval:
116 return 0;
Trond Myklebust980802e2005-06-13 11:14:01 -0400117force_reval:
118 return __nfs_revalidate_inode(server, inode);
119}
120
Andrew Morton965c8e52012-12-17 15:59:39 -0800121loff_t nfs_file_llseek(struct file *filp, loff_t offset, int whence)
Trond Myklebust980802e2005-06-13 11:14:01 -0400122{
Al Viro6de14722013-09-16 10:53:17 -0400123 dprintk("NFS: llseek file(%pD2, %lld, %d)\n",
124 filp, offset, whence);
Chuck Leverb84e06c2008-06-11 17:55:34 -0400125
Josef Bacik06222e42011-07-18 13:21:38 -0400126 /*
Andrew Morton965c8e52012-12-17 15:59:39 -0800127 * whence == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate
Josef Bacik06222e42011-07-18 13:21:38 -0400128 * the cached file length
129 */
Andrew Morton965c8e52012-12-17 15:59:39 -0800130 if (whence != SEEK_SET && whence != SEEK_CUR) {
Trond Myklebust980802e2005-06-13 11:14:01 -0400131 struct inode *inode = filp->f_mapping->host;
Trond Myklebustd5e66342008-09-23 17:28:35 -0400132
Trond Myklebust980802e2005-06-13 11:14:01 -0400133 int retval = nfs_revalidate_file_size(inode, filp);
134 if (retval < 0)
135 return (loff_t)retval;
Andi Kleen79835a712011-09-15 16:06:52 -0700136 }
Trond Myklebustd5e66342008-09-23 17:28:35 -0400137
Andrew Morton965c8e52012-12-17 15:59:39 -0800138 return generic_file_llseek(filp, offset, whence);
Trond Myklebust980802e2005-06-13 11:14:01 -0400139}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400140EXPORT_SYMBOL_GPL(nfs_file_llseek);
Trond Myklebust980802e2005-06-13 11:14:01 -0400141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142/*
143 * Flush all dirty pages, and check for write errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 */
Trond Myklebust5445b1f2015-09-05 19:06:58 -0400145static int
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700146nfs_file_flush(struct file *file, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147{
Al Viro6de14722013-09-16 10:53:17 -0400148 struct inode *inode = file_inode(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
Al Viro6de14722013-09-16 10:53:17 -0400150 dprintk("NFS: flush(%pD2)\n", file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
Chuck Leverc2459dc2010-02-01 14:17:14 -0500152 nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 if ((file->f_mode & FMODE_WRITE) == 0)
154 return 0;
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400155
Trond Myklebust7fe5c392009-03-19 15:35:50 -0400156 /* Flush writes to the server and return any errors */
Trond Myklebustaf7fa162010-07-31 14:29:06 -0400157 return vfs_fsync(file, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158}
159
Bryan Schumakerce4ef7c2012-07-16 16:39:15 -0400160ssize_t
Al Viro3aa2d192014-04-02 20:14:12 -0400161nfs_file_read(struct kiocb *iocb, struct iov_iter *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162{
Al Viro6de14722013-09-16 10:53:17 -0400163 struct inode *inode = file_inode(iocb->ki_filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 ssize_t result;
165
Al Viro2ba48ce2015-04-09 13:52:01 -0400166 if (iocb->ki_flags & IOCB_DIRECT)
Christoph Hellwigc8b8e322016-04-07 08:51:58 -0700167 return nfs_file_direct_read(iocb, to);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Al Viro619d30b2014-03-04 21:53:33 -0500169 dprintk("NFS: read(%pD2, %zu@%lu)\n",
Al Viro6de14722013-09-16 10:53:17 -0400170 iocb->ki_filp,
Al Viro3aa2d192014-04-02 20:14:12 -0400171 iov_iter_count(to), (unsigned long) iocb->ki_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
Trond Myklebust874f9462015-03-02 23:32:08 -0500173 result = nfs_revalidate_mapping_protected(inode, iocb->ki_filp->f_mapping);
Chuck Lever4184dcf2010-02-01 14:17:23 -0500174 if (!result) {
Al Viro3aa2d192014-04-02 20:14:12 -0400175 result = generic_file_read_iter(iocb, to);
Chuck Lever4184dcf2010-02-01 14:17:23 -0500176 if (result > 0)
177 nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);
178 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 return result;
180}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400181EXPORT_SYMBOL_GPL(nfs_file_read);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
Bryan Schumakerce4ef7c2012-07-16 16:39:15 -0400183ssize_t
Jens Axboef0930ff2007-06-01 11:51:43 +0200184nfs_file_splice_read(struct file *filp, loff_t *ppos,
185 struct pipe_inode_info *pipe, size_t count,
186 unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187{
Al Viro6de14722013-09-16 10:53:17 -0400188 struct inode *inode = file_inode(filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 ssize_t res;
190
Al Viro6de14722013-09-16 10:53:17 -0400191 dprintk("NFS: splice_read(%pD2, %lu@%Lu)\n",
192 filp, (unsigned long) count, (unsigned long long) *ppos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
Trond Myklebust874f9462015-03-02 23:32:08 -0500194 res = nfs_revalidate_mapping_protected(inode, filp->f_mapping);
Chuck Leveraa2f1ef2010-02-01 14:17:32 -0500195 if (!res) {
Jens Axboef0930ff2007-06-01 11:51:43 +0200196 res = generic_file_splice_read(filp, ppos, pipe, count, flags);
Chuck Leveraa2f1ef2010-02-01 14:17:32 -0500197 if (res > 0)
198 nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, res);
199 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 return res;
201}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400202EXPORT_SYMBOL_GPL(nfs_file_splice_read);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
Bryan Schumakerce4ef7c2012-07-16 16:39:15 -0400204int
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
206{
Al Viro6de14722013-09-16 10:53:17 -0400207 struct inode *inode = file_inode(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 int status;
209
Al Viro6de14722013-09-16 10:53:17 -0400210 dprintk("NFS: mmap(%pD2)\n", file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
Trond Myklebuste1ebfd32009-03-11 14:37:54 -0400212 /* Note: generic_file_mmap() returns ENOSYS on nommu systems
213 * so we call that before revalidating the mapping
214 */
215 status = generic_file_mmap(file, vma);
Trond Myklebust94387fb2007-07-22 17:09:05 -0400216 if (!status) {
217 vma->vm_ops = &nfs_file_vm_ops;
Trond Myklebuste1ebfd32009-03-11 14:37:54 -0400218 status = nfs_revalidate_mapping(inode, file->f_mapping);
Trond Myklebust94387fb2007-07-22 17:09:05 -0400219 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 return status;
221}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400222EXPORT_SYMBOL_GPL(nfs_file_mmap);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
224/*
225 * Flush any dirty pages for this process, and check for write errors.
226 * The return status from this call provides a reliable indication of
227 * whether any write errors occurred for this process.
Trond Myklebustaf7fa162010-07-31 14:29:06 -0400228 *
229 * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
230 * disk, but it retrieves and clears ctx->error after synching, despite
231 * the two being set at the same time in nfs_context_set_write_error().
232 * This is because the former is used to notify the _next_ call to
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300233 * nfs_file_write() that a write error occurred, and hence cause it to
Trond Myklebustaf7fa162010-07-31 14:29:06 -0400234 * fall back to doing a synchronous write.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 */
Christoph Hellwig4ff79bc2016-03-02 17:35:54 +0100236static int
Bryan Schumakera5c58892012-06-20 15:53:42 -0400237nfs_file_fsync_commit(struct file *file, loff_t start, loff_t end, int datasync)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238{
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400239 struct nfs_open_context *ctx = nfs_file_open_context(file);
Al Viro6de14722013-09-16 10:53:17 -0400240 struct inode *inode = file_inode(file);
Trond Myklebust05990d12012-09-11 16:01:22 -0400241 int have_error, do_resend, status;
Trond Myklebustaf7fa162010-07-31 14:29:06 -0400242 int ret = 0;
243
Al Viro6de14722013-09-16 10:53:17 -0400244 dprintk("NFS: fsync file(%pD2) datasync %d\n", file, datasync);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
Chuck Lever91d5b472006-03-20 13:44:14 -0500246 nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
Trond Myklebust05990d12012-09-11 16:01:22 -0400247 do_resend = test_and_clear_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags);
Trond Myklebustaf7fa162010-07-31 14:29:06 -0400248 have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
249 status = nfs_commit_inode(inode, FLUSH_SYNC);
250 have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
Trond Myklebust05990d12012-09-11 16:01:22 -0400251 if (have_error) {
Trond Myklebustaf7fa162010-07-31 14:29:06 -0400252 ret = xchg(&ctx->error, 0);
Trond Myklebust05990d12012-09-11 16:01:22 -0400253 if (ret)
254 goto out;
255 }
256 if (status < 0) {
Trond Myklebustaf7fa162010-07-31 14:29:06 -0400257 ret = status;
Trond Myklebust05990d12012-09-11 16:01:22 -0400258 goto out;
259 }
260 do_resend |= test_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags);
261 if (do_resend)
262 ret = -EAGAIN;
263out:
Bryan Schumakera5c58892012-06-20 15:53:42 -0400264 return ret;
265}
266
Christoph Hellwig4ff79bc2016-03-02 17:35:54 +0100267int
Bryan Schumakera5c58892012-06-20 15:53:42 -0400268nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
269{
270 int ret;
Al Viro496ad9a2013-01-23 17:07:38 -0500271 struct inode *inode = file_inode(file);
Bryan Schumakera5c58892012-06-20 15:53:42 -0400272
Trond Myklebustf4ce1292013-08-19 18:59:33 -0400273 trace_nfs_fsync_enter(inode);
274
Christoph Hellwig95d9f6c2016-03-02 17:35:55 +0100275 inode_dio_wait(inode);
Trond Myklebust05990d12012-09-11 16:01:22 -0400276 do {
277 ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
278 if (ret != 0)
279 break;
Trond Myklebust05990d12012-09-11 16:01:22 -0400280 ret = nfs_file_fsync_commit(file, start, end, datasync);
Christoph Hellwig4ff79bc2016-03-02 17:35:54 +0100281 if (!ret)
282 ret = pnfs_sync_inode(inode, !!datasync);
Trond Myklebustdcfc4f22012-09-11 16:19:38 -0400283 /*
284 * If nfs_file_fsync_commit detected a server reboot, then
285 * resend all dirty pages that might have been covered by
286 * the NFS_CONTEXT_RESEND_WRITES flag
287 */
288 start = 0;
289 end = LLONG_MAX;
Trond Myklebust05990d12012-09-11 16:01:22 -0400290 } while (ret == -EAGAIN);
291
Trond Myklebustf4ce1292013-08-19 18:59:33 -0400292 trace_nfs_fsync_exit(inode, ret);
Trond Myklebustaf7fa162010-07-31 14:29:06 -0400293 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294}
Christoph Hellwig4ff79bc2016-03-02 17:35:54 +0100295EXPORT_SYMBOL_GPL(nfs_file_fsync);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
297/*
Peter Staubach38c73042009-08-10 08:54:16 -0400298 * Decide whether a read/modify/write cycle may be more efficient
299 * then a modify/write/read cycle when writing to a page in the
300 * page cache.
301 *
302 * The modify/write/read cycle may occur if a page is read before
303 * being completely filled by the writer. In this situation, the
304 * page must be completely written to stable storage on the server
305 * before it can be refilled by reading in the page from the server.
306 * This can lead to expensive, small, FILE_SYNC mode writes being
307 * done.
308 *
309 * It may be more efficient to read the page first if the file is
310 * open for reading in addition to writing, the page is not marked
311 * as Uptodate, it is not dirty or waiting to be committed,
312 * indicating that it was previously allocated and then modified,
313 * that there were valid bytes of data in that range of the file,
314 * and that the new data won't completely replace the old data in
315 * that range of the file.
316 */
317static int nfs_want_read_modify_write(struct file *file, struct page *page,
318 loff_t pos, unsigned len)
319{
320 unsigned int pglen = nfs_page_length(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300321 unsigned int offset = pos & (PAGE_SIZE - 1);
Peter Staubach38c73042009-08-10 08:54:16 -0400322 unsigned int end = offset + len;
323
Christoph Hellwig612aa982014-09-10 08:23:30 -0700324 if (pnfs_ld_read_whole_page(file->f_mapping->host)) {
325 if (!PageUptodate(page))
326 return 1;
327 return 0;
328 }
329
Peter Staubach38c73042009-08-10 08:54:16 -0400330 if ((file->f_mode & FMODE_READ) && /* open for read? */
331 !PageUptodate(page) && /* Uptodate? */
332 !PagePrivate(page) && /* i/o request already? */
333 pglen && /* valid bytes of file? */
334 (end < pglen || offset)) /* replace all valid bytes? */
335 return 1;
336 return 0;
337}
338
339/*
Nick Piggin4899f9c2007-10-16 01:25:16 -0700340 * This does the "real" work of the write. We must allocate and lock the
341 * page to be sent back to the generic routine, which then copies the
342 * data from user space.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 *
344 * If the writer ends up delaying the write, the writer needs to
345 * increment the page use counts until he is done with the page.
346 */
Nick Piggin4899f9c2007-10-16 01:25:16 -0700347static int nfs_write_begin(struct file *file, struct address_space *mapping,
348 loff_t pos, unsigned len, unsigned flags,
349 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350{
Nick Piggin4899f9c2007-10-16 01:25:16 -0700351 int ret;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300352 pgoff_t index = pos >> PAGE_SHIFT;
Nick Piggin4899f9c2007-10-16 01:25:16 -0700353 struct page *page;
Peter Staubach38c73042009-08-10 08:54:16 -0400354 int once_thru = 0;
Nick Piggin4899f9c2007-10-16 01:25:16 -0700355
Niels de Vos1e8968c2013-12-17 18:20:16 +0100356 dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
Al Viro6de14722013-09-16 10:53:17 -0400357 file, mapping->host->i_ino, len, (long long) pos);
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400358
Peter Staubach38c73042009-08-10 08:54:16 -0400359start:
Trond Myklebust72cb77f2009-03-11 14:10:30 -0400360 /*
Trond Myklebustaa5accea2015-02-27 22:54:19 -0500361 * Wait for O_DIRECT to complete
362 */
Christoph Hellwig95d9f6c2016-03-02 17:35:55 +0100363 inode_dio_wait(mapping->host);
Trond Myklebust72cb77f2009-03-11 14:10:30 -0400364
Nick Piggin54566b22009-01-04 12:00:53 -0800365 page = grab_cache_page_write_begin(mapping, index, flags);
Nick Piggin4899f9c2007-10-16 01:25:16 -0700366 if (!page)
367 return -ENOMEM;
368 *pagep = page;
369
370 ret = nfs_flush_incompatible(file, page);
371 if (ret) {
372 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300373 put_page(page);
Peter Staubach38c73042009-08-10 08:54:16 -0400374 } else if (!once_thru &&
375 nfs_want_read_modify_write(file, page, pos, len)) {
376 once_thru = 1;
377 ret = nfs_readpage(file, page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300378 put_page(page);
Peter Staubach38c73042009-08-10 08:54:16 -0400379 if (!ret)
380 goto start;
Nick Piggin4899f9c2007-10-16 01:25:16 -0700381 }
382 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383}
384
Nick Piggin4899f9c2007-10-16 01:25:16 -0700385static int nfs_write_end(struct file *file, struct address_space *mapping,
386 loff_t pos, unsigned len, unsigned copied,
387 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388{
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300389 unsigned offset = pos & (PAGE_SIZE - 1);
Andy Adamsondc248262013-08-14 11:59:16 -0400390 struct nfs_open_context *ctx = nfs_file_open_context(file);
Nick Piggin4899f9c2007-10-16 01:25:16 -0700391 int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
Niels de Vos1e8968c2013-12-17 18:20:16 +0100393 dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n",
Al Viro6de14722013-09-16 10:53:17 -0400394 file, mapping->host->i_ino, len, (long long) pos);
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400395
Trond Myklebustefc91ed2008-06-10 18:31:00 -0400396 /*
397 * Zero any uninitialised parts of the page, and then mark the page
398 * as up to date if it turns out that we're extending the file.
399 */
400 if (!PageUptodate(page)) {
401 unsigned pglen = nfs_page_length(page);
402 unsigned end = offset + len;
403
404 if (pglen == 0) {
405 zero_user_segments(page, 0, offset,
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300406 end, PAGE_SIZE);
Trond Myklebustefc91ed2008-06-10 18:31:00 -0400407 SetPageUptodate(page);
408 } else if (end >= pglen) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300409 zero_user_segment(page, end, PAGE_SIZE);
Trond Myklebustefc91ed2008-06-10 18:31:00 -0400410 if (offset == 0)
411 SetPageUptodate(page);
412 } else
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300413 zero_user_segment(page, pglen, PAGE_SIZE);
Trond Myklebustefc91ed2008-06-10 18:31:00 -0400414 }
415
Nick Piggin4899f9c2007-10-16 01:25:16 -0700416 status = nfs_updatepage(file, page, offset, copied);
Nick Piggin4899f9c2007-10-16 01:25:16 -0700417
418 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300419 put_page(page);
Nick Piggin4899f9c2007-10-16 01:25:16 -0700420
Chuck Lever3d509e52007-12-20 14:55:04 -0500421 if (status < 0)
422 return status;
Andy Adamson2701d082012-05-24 13:13:24 -0400423 NFS_I(mapping->host)->write_io += copied;
Andy Adamsondc248262013-08-14 11:59:16 -0400424
425 if (nfs_ctx_key_to_expire(ctx)) {
426 status = nfs_wb_all(mapping->host);
427 if (status < 0)
428 return status;
429 }
430
Chuck Lever3d509e52007-12-20 14:55:04 -0500431 return copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432}
433
David Howells6b9b3512009-04-03 16:42:41 +0100434/*
435 * Partially or wholly invalidate a page
436 * - Release the private state associated with a page if undergoing complete
437 * page invalidation
David Howells545db452009-04-03 16:42:44 +0100438 * - Called if either PG_private or PG_fscache is set on the page
David Howells6b9b3512009-04-03 16:42:41 +0100439 * - Caller holds page lock
440 */
Lukas Czernerd47992f2013-05-21 23:17:23 -0400441static void nfs_invalidate_page(struct page *page, unsigned int offset,
442 unsigned int length)
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500443{
Lukas Czernerd47992f2013-05-21 23:17:23 -0400444 dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %u, %u)\n",
445 page, offset, length);
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400446
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300447 if (offset != 0 || length < PAGE_SIZE)
Trond Myklebust1c759502006-10-09 16:18:38 -0400448 return;
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400449 /* Cancel any unstarted writes on this page */
Mel Gormand56b4dd2012-07-31 16:45:06 -0700450 nfs_wb_page_cancel(page_file_mapping(page)->host, page);
David Howells545db452009-04-03 16:42:44 +0100451
452 nfs_fscache_invalidate_page(page, page->mapping->host);
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500453}
454
David Howells6b9b3512009-04-03 16:42:41 +0100455/*
456 * Attempt to release the private state associated with a page
David Howells545db452009-04-03 16:42:44 +0100457 * - Called if either PG_private or PG_fscache is set on the page
David Howells6b9b3512009-04-03 16:42:41 +0100458 * - Caller holds page lock
459 * - Return true (may release page) or false (may not)
460 */
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500461static int nfs_release_page(struct page *page, gfp_t gfp)
462{
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400463 dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
464
Trond Myklebuste3db7692007-01-10 23:15:39 -0800465 /* If PagePrivate() is set, then the page is not freeable */
David Howells545db452009-04-03 16:42:44 +0100466 if (PagePrivate(page))
467 return 0;
468 return nfs_fscache_release_page(page, gfp);
Trond Myklebuste3db7692007-01-10 23:15:39 -0800469}
470
Mel Gormanf919b192013-07-03 15:02:06 -0700471static void nfs_check_dirty_writeback(struct page *page,
472 bool *dirty, bool *writeback)
473{
474 struct nfs_inode *nfsi;
475 struct address_space *mapping = page_file_mapping(page);
476
477 if (!mapping || PageSwapCache(page))
478 return;
479
480 /*
481 * Check if an unstable page is currently being committed and
482 * if so, have the VM treat it as if the page is under writeback
483 * so it will not block due to pages that will shortly be freeable.
484 */
485 nfsi = NFS_I(mapping->host);
Trond Myklebustaf7cf052015-09-29 20:34:05 -0400486 if (atomic_read(&nfsi->commit_info.rpcs_out)) {
Mel Gormanf919b192013-07-03 15:02:06 -0700487 *writeback = true;
488 return;
489 }
490
491 /*
492 * If PagePrivate() is set, then the page is not freeable and as the
493 * inode is not being committed, it's not going to be cleaned in the
494 * near future so treat it as dirty
495 */
496 if (PagePrivate(page))
497 *dirty = true;
498}
499
David Howells6b9b3512009-04-03 16:42:41 +0100500/*
501 * Attempt to clear the private state associated with a page when an error
502 * occurs that requires the cached contents of an inode to be written back or
503 * destroyed
David Howells545db452009-04-03 16:42:44 +0100504 * - Called if either PG_private or fscache is set on the page
David Howells6b9b3512009-04-03 16:42:41 +0100505 * - Caller holds page lock
506 * - Return 0 if successful, -error otherwise
507 */
Trond Myklebuste3db7692007-01-10 23:15:39 -0800508static int nfs_launder_page(struct page *page)
509{
Mel Gormand56b4dd2012-07-31 16:45:06 -0700510 struct inode *inode = page_file_mapping(page)->host;
David Howells545db452009-04-03 16:42:44 +0100511 struct nfs_inode *nfsi = NFS_I(inode);
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400512
513 dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
514 inode->i_ino, (long long)page_offset(page));
515
David Howells545db452009-04-03 16:42:44 +0100516 nfs_fscache_wait_on_page_write(nfsi, page);
Peng Taod6c843b2015-12-05 16:20:43 +0800517 return nfs_wb_launder_page(inode, page);
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500518}
519
Mel Gormana564b8f2012-07-31 16:45:12 -0700520static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
521 sector_t *span)
522{
Jeff Laytondad2b012014-09-10 09:03:55 -0400523 struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host);
524
Mel Gormana564b8f2012-07-31 16:45:12 -0700525 *span = sis->pages;
Jeff Laytondad2b012014-09-10 09:03:55 -0400526
Jeff Layton3c87ef62015-06-03 16:14:25 -0400527 return rpc_clnt_swap_activate(clnt);
Mel Gormana564b8f2012-07-31 16:45:12 -0700528}
529
530static void nfs_swap_deactivate(struct file *file)
531{
Jeff Laytondad2b012014-09-10 09:03:55 -0400532 struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host);
533
Jeff Layton3c87ef62015-06-03 16:14:25 -0400534 rpc_clnt_swap_deactivate(clnt);
Mel Gormana564b8f2012-07-31 16:45:12 -0700535}
Mel Gormana564b8f2012-07-31 16:45:12 -0700536
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700537const struct address_space_operations nfs_file_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 .readpage = nfs_readpage,
539 .readpages = nfs_readpages,
Trond Myklebust9cccef92007-07-22 17:09:05 -0400540 .set_page_dirty = __set_page_dirty_nobuffers,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 .writepage = nfs_writepage,
542 .writepages = nfs_writepages,
Nick Piggin4899f9c2007-10-16 01:25:16 -0700543 .write_begin = nfs_write_begin,
544 .write_end = nfs_write_end,
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500545 .invalidatepage = nfs_invalidate_page,
546 .releasepage = nfs_release_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 .direct_IO = nfs_direct_IO,
Trond Myklebust074cc1d2009-08-10 08:54:13 -0400548 .migratepage = nfs_migrate_page,
Trond Myklebuste3db7692007-01-10 23:15:39 -0800549 .launder_page = nfs_launder_page,
Mel Gormanf919b192013-07-03 15:02:06 -0700550 .is_dirty_writeback = nfs_check_dirty_writeback,
Andi Kleenf590f332009-09-16 11:50:17 +0200551 .error_remove_page = generic_error_remove_page,
Mel Gormana564b8f2012-07-31 16:45:12 -0700552 .swap_activate = nfs_swap_activate,
553 .swap_deactivate = nfs_swap_deactivate,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554};
555
David Howells6b9b3512009-04-03 16:42:41 +0100556/*
557 * Notification that a PTE pointing to an NFS page is about to be made
558 * writable, implying that someone is about to modify the page through a
559 * shared-writable mapping
560 */
Nick Pigginc2ec1752009-03-31 15:23:21 -0700561static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
Trond Myklebust94387fb2007-07-22 17:09:05 -0400562{
Nick Pigginc2ec1752009-03-31 15:23:21 -0700563 struct page *page = vmf->page;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400564 struct file *filp = vma->vm_file;
Al Viro6de14722013-09-16 10:53:17 -0400565 struct inode *inode = file_inode(filp);
Trond Myklebust94387fb2007-07-22 17:09:05 -0400566 unsigned pagelen;
Trond Myklebustbc4866b2010-10-04 17:59:08 -0400567 int ret = VM_FAULT_NOPAGE;
Nick Piggin4899f9c2007-10-16 01:25:16 -0700568 struct address_space *mapping;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400569
Niels de Vos1e8968c2013-12-17 18:20:16 +0100570 dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
Al Viro6de14722013-09-16 10:53:17 -0400571 filp, filp->f_mapping->host->i_ino,
Chuck Leverb7eaefa2008-06-11 17:55:50 -0400572 (long long)page_offset(page));
573
David Howells545db452009-04-03 16:42:44 +0100574 /* make sure the cache has finished storing the page */
Al Viro6de14722013-09-16 10:53:17 -0400575 nfs_fscache_wait_on_page_write(NFS_I(inode), page);
David Howells545db452009-04-03 16:42:44 +0100576
Trond Myklebustef070dc2015-03-03 00:06:35 -0500577 wait_on_bit_action(&NFS_I(inode)->flags, NFS_INO_INVALIDATING,
578 nfs_wait_bit_killable, TASK_KILLABLE);
579
Trond Myklebust94387fb2007-07-22 17:09:05 -0400580 lock_page(page);
Mel Gormand56b4dd2012-07-31 16:45:06 -0700581 mapping = page_file_mapping(page);
Al Viro6de14722013-09-16 10:53:17 -0400582 if (mapping != inode->i_mapping)
Trond Myklebust8b1f9ee2008-01-22 17:13:06 -0500583 goto out_unlock;
584
Trond Myklebust2aeb98f2012-01-17 22:04:26 -0500585 wait_on_page_writeback(page);
586
Trond Myklebust94387fb2007-07-22 17:09:05 -0400587 pagelen = nfs_page_length(page);
Trond Myklebust8b1f9ee2008-01-22 17:13:06 -0500588 if (pagelen == 0)
589 goto out_unlock;
590
Trond Myklebustbc4866b2010-10-04 17:59:08 -0400591 ret = VM_FAULT_LOCKED;
592 if (nfs_flush_incompatible(filp, page) == 0 &&
593 nfs_updatepage(filp, page, 0, pagelen) == 0)
594 goto out;
Trond Myklebust8b1f9ee2008-01-22 17:13:06 -0500595
Trond Myklebustbc4866b2010-10-04 17:59:08 -0400596 ret = VM_FAULT_SIGBUS;
Trond Myklebust8b1f9ee2008-01-22 17:13:06 -0500597out_unlock:
Trond Myklebust94387fb2007-07-22 17:09:05 -0400598 unlock_page(page);
Trond Myklebustbc4866b2010-10-04 17:59:08 -0400599out:
600 return ret;
Trond Myklebust94387fb2007-07-22 17:09:05 -0400601}
602
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +0400603static const struct vm_operations_struct nfs_file_vm_ops = {
Trond Myklebust94387fb2007-07-22 17:09:05 -0400604 .fault = filemap_fault,
Kirill A. Shutemovf1820362014-04-07 15:37:19 -0700605 .map_pages = filemap_map_pages,
Trond Myklebust94387fb2007-07-22 17:09:05 -0400606 .page_mkwrite = nfs_vm_page_mkwrite,
607};
608
Trond Myklebust7e94d6c2015-08-17 16:55:18 -0500609static int nfs_need_check_write(struct file *filp, struct inode *inode)
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400610{
611 struct nfs_open_context *ctx;
612
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400613 ctx = nfs_file_open_context(filp);
Andy Adamsondc248262013-08-14 11:59:16 -0400614 if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags) ||
615 nfs_ctx_key_to_expire(ctx))
Trond Myklebust7b159fc2007-07-25 14:09:54 -0400616 return 1;
617 return 0;
618}
619
Al Viroedaf4362014-04-03 14:07:25 -0400620ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621{
Al Viro6de14722013-09-16 10:53:17 -0400622 struct file *file = iocb->ki_filp;
623 struct inode *inode = file_inode(file);
Chuck Lever7e381172010-02-01 14:17:41 -0500624 unsigned long written = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 ssize_t result;
626
Al Viro6de14722013-09-16 10:53:17 -0400627 result = nfs_key_timeout_notify(file, inode);
Andy Adamsondc248262013-08-14 11:59:16 -0400628 if (result)
629 return result;
630
Trond Myklebust89698b22016-06-23 10:35:48 -0400631 if (iocb->ki_flags & IOCB_DIRECT)
Al Viro65a4a1c2015-04-09 14:11:08 -0400632 return nfs_file_direct_write(iocb, from);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
Al Viro619d30b2014-03-04 21:53:33 -0500634 dprintk("NFS: write(%pD2, %zu@%Ld)\n",
Trond Myklebust18290652016-06-23 15:00:42 -0400635 file, iov_iter_count(from), (long long) iocb->ki_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 if (IS_SWAPFILE(inode))
638 goto out_swapfile;
Trond Myklebust7d52e862005-06-22 17:16:30 +0000639 /*
640 * O_APPEND implies that we must revalidate the file length.
641 */
Al Viro2ba48ce2015-04-09 13:52:01 -0400642 if (iocb->ki_flags & IOCB_APPEND) {
Al Viro6de14722013-09-16 10:53:17 -0400643 result = nfs_revalidate_file_size(inode, file);
Trond Myklebust7d52e862005-06-22 17:16:30 +0000644 if (result)
645 goto out;
Trond Myklebustfe51beec2005-06-22 17:16:30 +0000646 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
Trond Myklebust18290652016-06-23 15:00:42 -0400648 inode_lock(inode);
649 result = generic_write_checks(iocb, from);
650 if (result > 0) {
651 current->backing_dev_info = inode_to_bdi(inode);
652 result = generic_perform_write(file, from, iocb->ki_pos);
653 current->backing_dev_info = NULL;
654 }
655 inode_unlock(inode);
656 if (result <= 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 goto out;
658
Trond Myklebust18290652016-06-23 15:00:42 -0400659 written = generic_write_sync(iocb, result);
660 iocb->ki_pos += written;
Chuck Lever7e381172010-02-01 14:17:41 -0500661
Trond Myklebust7e94d6c2015-08-17 16:55:18 -0500662 /* Return error values */
Trond Myklebust18290652016-06-23 15:00:42 -0400663 if (nfs_need_check_write(file, inode)) {
Al Viro6de14722013-09-16 10:53:17 -0400664 int err = vfs_fsync(file, 0);
Trond Myklebust200baa22006-12-05 00:35:40 -0500665 if (err < 0)
666 result = err;
667 }
Trond Myklebust18290652016-06-23 15:00:42 -0400668 nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669out:
670 return result;
671
672out_swapfile:
673 printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
Trond Myklebust18290652016-06-23 15:00:42 -0400674 return -EBUSY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400676EXPORT_SYMBOL_GPL(nfs_file_write);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400678static int
679do_getlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680{
681 struct inode *inode = filp->f_mapping->host;
682 int status = 0;
Sergey Vlasov21ac19d2010-11-28 21:04:05 +0000683 unsigned int saved_type = fl->fl_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
Trond Myklebust039c4d72005-10-18 14:20:16 -0700685 /* Try local locking first */
J. Bruce Fields6d34ac12007-05-11 16:09:32 -0400686 posix_test_lock(filp, fl);
687 if (fl->fl_type != F_UNLCK) {
688 /* found a conflict */
Trond Myklebust039c4d72005-10-18 14:20:16 -0700689 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 }
Sergey Vlasov21ac19d2010-11-28 21:04:05 +0000691 fl->fl_type = saved_type;
Trond Myklebust039c4d72005-10-18 14:20:16 -0700692
Bryan Schumaker011e2a72012-06-20 15:53:43 -0400693 if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
Trond Myklebust039c4d72005-10-18 14:20:16 -0700694 goto out_noconflict;
695
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400696 if (is_local)
Trond Myklebust039c4d72005-10-18 14:20:16 -0700697 goto out_noconflict;
698
699 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
700out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 return status;
Trond Myklebust039c4d72005-10-18 14:20:16 -0700702out_noconflict:
703 fl->fl_type = F_UNLCK;
704 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705}
706
707static int do_vfs_lock(struct file *file, struct file_lock *fl)
708{
Benjamin Coddington4f656362015-10-22 13:38:14 -0400709 return locks_lock_file_wait(file, fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710}
711
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400712static int
713do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714{
715 struct inode *inode = filp->f_mapping->host;
Trond Myklebust7a8203d2013-04-08 21:49:53 -0400716 struct nfs_lock_context *l_ctx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 int status;
718
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 /*
720 * Flush all pending writes before doing anything
721 * with locks..
722 */
Trond Myklebustd9dabc12015-03-26 15:55:49 -0400723 vfs_fsync(filp, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
Trond Myklebust7a8203d2013-04-08 21:49:53 -0400725 l_ctx = nfs_get_lock_context(nfs_file_open_context(filp));
726 if (!IS_ERR(l_ctx)) {
Benjamin Coddington210c7c12016-01-06 10:40:18 -0500727 status = nfs_iocounter_wait(l_ctx);
Trond Myklebust7a8203d2013-04-08 21:49:53 -0400728 nfs_put_lock_context(l_ctx);
729 if (status < 0)
730 return status;
731 }
732
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 /* NOTE: special case
734 * If we're signalled while cleaning up locks on process exit, we
735 * still need to complete the unlock.
736 */
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400737 /*
738 * Use local locking if mounted with "-onolock" or with appropriate
739 * "-olocal_lock="
740 */
741 if (!is_local)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
743 else
744 status = do_vfs_lock(filp, fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 return status;
746}
747
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400748static int
749do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750{
751 struct inode *inode = filp->f_mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 int status;
753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 /*
755 * Flush all pending writes before doing anything
756 * with locks..
757 */
Trond Myklebust29884df2005-12-13 16:13:54 -0500758 status = nfs_sync_mapping(filp->f_mapping);
759 if (status != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 goto out;
761
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400762 /*
763 * Use local locking if mounted with "-onolock" or with appropriate
764 * "-olocal_lock="
765 */
766 if (!is_local)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 status = NFS_PROTO(inode)->lock(filp, cmd, fl);
Trond Myklebustc4d7c402008-04-01 20:26:52 -0400768 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 status = do_vfs_lock(filp, fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 if (status < 0)
771 goto out;
Ricardo Labiaga6b967242010-10-12 16:30:05 -0700772
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 /*
Ricardo Labiaga6b967242010-10-12 16:30:05 -0700774 * Revalidate the cache if the server has time stamps granular
775 * enough to detect subsecond changes. Otherwise, clear the
776 * cache to prevent missing any changes.
777 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 * This makes locking act as a cache coherency point.
779 */
Trond Myklebust29884df2005-12-13 16:13:54 -0500780 nfs_sync_mapping(filp->f_mapping);
Trond Myklebustca0daa22016-06-08 17:08:28 -0400781 if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
782 nfs_zap_mapping(inode, filp->f_mapping);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 return status;
785}
786
787/*
788 * Lock a (portion of) a file
789 */
Bryan Schumakerce4ef7c2012-07-16 16:39:15 -0400790int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791{
Chuck Lever6da24bc2008-06-11 17:55:58 -0400792 struct inode *inode = filp->f_mapping->host;
Trond Myklebust21162712008-05-20 19:34:39 -0400793 int ret = -ENOLCK;
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400794 int is_local = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795
Al Viro6de14722013-09-16 10:53:17 -0400796 dprintk("NFS: lock(%pD2, t=%x, fl=%x, r=%lld:%lld)\n",
797 filp, fl->fl_type, fl->fl_flags,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 (long long)fl->fl_start, (long long)fl->fl_end);
Chuck Lever6da24bc2008-06-11 17:55:58 -0400799
Chuck Lever91d5b472006-03-20 13:44:14 -0500800 nfs_inc_stats(inode, NFSIOS_VFSLOCK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
802 /* No mandatory locks over NFS */
Pavel Emelyanovdfad9442007-10-01 14:41:15 -0700803 if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
Trond Myklebust21162712008-05-20 19:34:39 -0400804 goto out_err;
805
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400806 if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FCNTL)
807 is_local = 1;
808
Trond Myklebust21162712008-05-20 19:34:39 -0400809 if (NFS_PROTO(inode)->lock_check_bounds != NULL) {
810 ret = NFS_PROTO(inode)->lock_check_bounds(fl);
811 if (ret < 0)
812 goto out_err;
813 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814
815 if (IS_GETLK(cmd))
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400816 ret = do_getlk(filp, cmd, fl, is_local);
Trond Myklebust21162712008-05-20 19:34:39 -0400817 else if (fl->fl_type == F_UNLCK)
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400818 ret = do_unlk(filp, cmd, fl, is_local);
Trond Myklebust21162712008-05-20 19:34:39 -0400819 else
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400820 ret = do_setlk(filp, cmd, fl, is_local);
Trond Myklebust21162712008-05-20 19:34:39 -0400821out_err:
822 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400824EXPORT_SYMBOL_GPL(nfs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825
826/*
827 * Lock a (portion of) a file
828 */
Bryan Schumakerce4ef7c2012-07-16 16:39:15 -0400829int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830{
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400831 struct inode *inode = filp->f_mapping->host;
832 int is_local = 0;
833
Al Viro6de14722013-09-16 10:53:17 -0400834 dprintk("NFS: flock(%pD2, t=%x, fl=%x)\n",
835 filp, fl->fl_type, fl->fl_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 if (!(fl->fl_flags & FL_FLOCK))
838 return -ENOLCK;
839
Jeff Laytonad0fcd42012-07-23 15:46:23 -0400840 /*
841 * The NFSv4 protocol doesn't support LOCK_MAND, which is not part of
842 * any standard. In principle we might be able to support LOCK_MAND
843 * on NFSv2/3 since NLMv3/4 support DOS share modes, but for now the
844 * NFS code is not set up for it.
845 */
846 if (fl->fl_type & LOCK_MAND)
847 return -EINVAL;
848
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400849 if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK)
850 is_local = 1;
851
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 /* We're simulating flock() locks using posix locks on the server */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 if (fl->fl_type == F_UNLCK)
Suresh Jayaraman5eebde22010-09-23 08:55:58 -0400854 return do_unlk(filp, cmd, fl, is_local);
855 return do_setlk(filp, cmd, fl, is_local);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400857EXPORT_SYMBOL_GPL(nfs_flock);
J. Bruce Fields370f6592007-06-08 15:23:34 -0400858
Jeff Layton04869582011-11-04 13:31:22 -0400859const struct file_operations nfs_file_operations = {
860 .llseek = nfs_file_llseek,
Al Viro3aa2d192014-04-02 20:14:12 -0400861 .read_iter = nfs_file_read,
Al Viroedaf4362014-04-03 14:07:25 -0400862 .write_iter = nfs_file_write,
Jeff Layton04869582011-11-04 13:31:22 -0400863 .mmap = nfs_file_mmap,
864 .open = nfs_file_open,
865 .flush = nfs_file_flush,
866 .release = nfs_file_release,
867 .fsync = nfs_file_fsync,
868 .lock = nfs_lock,
869 .flock = nfs_flock,
870 .splice_read = nfs_file_splice_read,
Al Viro4da54c22014-04-05 04:37:17 -0400871 .splice_write = iter_file_splice_write,
Jeff Layton04869582011-11-04 13:31:22 -0400872 .check_flags = nfs_check_flags,
Jeff Layton1c994a02014-08-27 06:49:41 -0400873 .setlease = simple_nosetlease,
Jeff Layton04869582011-11-04 13:31:22 -0400874};
Bryan Schumakerddda8e02012-07-30 16:05:23 -0400875EXPORT_SYMBOL_GPL(nfs_file_operations);