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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * linux/fs/9p/vfs_file.c
3 *
4 * This file contians vfs file ops for 9P2000.
5 *
6 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to:
20 * Free Software Foundation
21 * 51 Franklin Street, Fifth Floor
22 * Boston, MA 02111-1301 USA
23 *
24 */
25
26#include <linux/module.h>
27#include <linux/errno.h>
28#include <linux/fs.h>
29#include <linux/sched.h>
30#include <linux/file.h>
31#include <linux/stat.h>
32#include <linux/string.h>
33#include <linux/inet.h>
34#include <linux/list.h>
35#include <asm/uaccess.h>
36#include <linux/idr.h>
37#include <net/9p/9p.h>
38#include <net/9p/client.h>
39
40#include "v9fs.h"
41#include "v9fs_vfs.h"
42#include "fid.h"
43
44static const struct file_operations v9fs_cached_file_operations;
45
46/**
47 * v9fs_file_open - open a file (or directory)
48 * @inode: inode to be opened
49 * @file: file being opened
50 *
51 */
52
53int v9fs_file_open(struct inode *inode, struct file *file)
54{
55 int err;
56 struct v9fs_session_info *v9ses;
57 struct p9_fid *fid;
58 int omode;
59
60 P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file);
61 v9ses = v9fs_inode2v9ses(inode);
62 omode = v9fs_uflags2omode(file->f_flags);
63 fid = file->private_data;
64 if (!fid) {
65 fid = v9fs_fid_clone(file->f_path.dentry);
66 if (IS_ERR(fid))
67 return PTR_ERR(fid);
68
69 err = p9_client_open(fid, omode);
70 if (err < 0) {
71 p9_client_clunk(fid);
72 return err;
73 }
74 if (omode & P9_OTRUNC) {
75 inode->i_size = 0;
76 inode->i_blocks = 0;
77 }
78 }
79
80 file->private_data = fid;
81 if ((fid->qid.version) && (v9ses->cache)) {
82 P9_DPRINTK(P9_DEBUG_VFS, "cached");
83 /* enable cached file options */
84 if(file->f_op == &v9fs_file_operations)
85 file->f_op = &v9fs_cached_file_operations;
86 }
87
88 return 0;
89}
90
91/**
92 * v9fs_file_lock - lock a file (or directory)
93 * @filp: file to be locked
94 * @cmd: lock command
95 * @fl: file lock structure
96 *
97 * Bugs: this looks like a local only lock, we should extend into 9P
98 * by using open exclusive
99 */
100
101static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
102{
103 int res = 0;
104 struct inode *inode = filp->f_path.dentry->d_inode;
105
106 P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
107
108 /* No mandatory locks */
109 if (__mandatory_lock(inode))
110 return -ENOLCK;
111
112 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
113 filemap_write_and_wait(inode->i_mapping);
114 invalidate_mapping_pages(&inode->i_data, 0, -1);
115 }
116
117 return res;
118}
119
120/**
121 * v9fs_file_read - read from a file
122 * @filp: file pointer to read
123 * @data: data buffer to read data into
124 * @count: size of buffer
125 * @offset: offset at which to read data
126 *
127 */
128static ssize_t
129v9fs_file_read(struct file *filp, char __user * data, size_t count,
130 loff_t * offset)
131{
132 int ret;
133 struct p9_fid *fid;
134
135 P9_DPRINTK(P9_DEBUG_VFS, "\n");
136 fid = filp->private_data;
137 ret = p9_client_uread(fid, data, *offset, count);
138 if (ret > 0)
139 *offset += ret;
140
141 return ret;
142}
143
144/**
145 * v9fs_file_write - write to a file
146 * @filp: file pointer to write
147 * @data: data buffer to write data from
148 * @count: size of buffer
149 * @offset: offset at which to write data
150 *
151 */
152
153static ssize_t
154v9fs_file_write(struct file *filp, const char __user * data,
155 size_t count, loff_t * offset)
156{
157 int ret;
158 struct p9_fid *fid;
159 struct inode *inode = filp->f_path.dentry->d_inode;
160
161 P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
162 (int)count, (int)*offset);
163
164 fid = filp->private_data;
165 ret = p9_client_uwrite(fid, data, *offset, count);
166 if (ret > 0) {
167 invalidate_inode_pages2_range(inode->i_mapping, *offset,
168 *offset+ret);
169 *offset += ret;
170 }
171
172 if (*offset > inode->i_size) {
173 inode->i_size = *offset;
174 inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
175 }
176
177 return ret;
178}
179
180static const struct file_operations v9fs_cached_file_operations = {
181 .llseek = generic_file_llseek,
182 .read = do_sync_read,
183 .aio_read = generic_file_aio_read,
184 .write = v9fs_file_write,
185 .open = v9fs_file_open,
186 .release = v9fs_dir_release,
187 .lock = v9fs_file_lock,
188 .mmap = generic_file_readonly_mmap,
189};
190
191const struct file_operations v9fs_file_operations = {
192 .llseek = generic_file_llseek,
193 .read = v9fs_file_read,
194 .write = v9fs_file_write,
195 .open = v9fs_file_open,
196 .release = v9fs_dir_release,
197 .lock = v9fs_file_lock,
198 .mmap = generic_file_readonly_mmap,
199};