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[PATCH] v9fs: zero copy implementation
[net-next-2.6.git] / fs / 9p / vfs_super.c
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1/*
2 * linux/fs/9p/vfs_super.c
3 *
4 * This file contians superblock ops for 9P2000. It is intended that
5 * you mount this file system on directories.
6 *
7 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to:
22 * Free Software Foundation
23 * 51 Franklin Street, Fifth Floor
24 * Boston, MA 02111-1301 USA
25 *
26 */
27
28#include <linux/kernel.h>
29#include <linux/config.h>
30#include <linux/module.h>
31#include <linux/errno.h>
32#include <linux/fs.h>
33#include <linux/file.h>
34#include <linux/stat.h>
35#include <linux/string.h>
36#include <linux/smp_lock.h>
37#include <linux/inet.h>
38#include <linux/pagemap.h>
39#include <linux/seq_file.h>
40#include <linux/mount.h>
41#include <linux/idr.h>
42
43#include "debug.h"
44#include "v9fs.h"
45#include "9p.h"
46#include "v9fs_vfs.h"
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47#include "fid.h"
48
49static void v9fs_clear_inode(struct inode *);
50static struct super_operations v9fs_super_ops;
51
52/**
53 * v9fs_clear_inode - release an inode
54 * @inode: inode to release
55 *
56 */
57
58static void v9fs_clear_inode(struct inode *inode)
59{
60 filemap_fdatawrite(inode->i_mapping);
61}
62
63/**
64 * v9fs_set_super - set the superblock
65 * @s: super block
66 * @data: file system specific data
67 *
68 */
69
70static int v9fs_set_super(struct super_block *s, void *data)
71{
72 s->s_fs_info = data;
73 return set_anon_super(s, data);
74}
75
76/**
77 * v9fs_fill_super - populate superblock with info
78 * @sb: superblock
79 * @v9ses: session information
80 *
81 */
82
83static void
84v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
85 int flags)
86{
87 sb->s_maxbytes = MAX_LFS_FILESIZE;
88 sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
89 sb->s_blocksize = 1 << sb->s_blocksize_bits;
90 sb->s_magic = V9FS_MAGIC;
91 sb->s_op = &v9fs_super_ops;
92
93 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
94 MS_NODIRATIME | MS_NOATIME;
95}
96
97/**
98 * v9fs_get_sb - mount a superblock
99 * @fs_type: file system type
100 * @flags: mount flags
101 * @dev_name: device name that was mounted
102 * @data: mount options
103 *
104 */
105
106static struct super_block *v9fs_get_sb(struct file_system_type
107 *fs_type, int flags,
108 const char *dev_name, void *data)
109{
110 struct super_block *sb = NULL;
111 struct v9fs_fcall *fcall = NULL;
112 struct inode *inode = NULL;
113 struct dentry *root = NULL;
114 struct v9fs_session_info *v9ses = NULL;
115 struct v9fs_fid *root_fid = NULL;
116 int mode = S_IRWXUGO | S_ISVTX;
117 uid_t uid = current->fsuid;
118 gid_t gid = current->fsgid;
119 int stat_result = 0;
120 int newfid = 0;
121 int retval = 0;
122
123 dprintk(DEBUG_VFS, " \n");
124
531b1094 125 v9ses = kmalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
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126 if (!v9ses)
127 return ERR_PTR(-ENOMEM);
128
531b1094 129 memset(v9ses, 0, sizeof(struct v9fs_session_info));
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130 if ((newfid = v9fs_session_init(v9ses, dev_name, data)) < 0) {
131 dprintk(DEBUG_ERROR, "problem initiating session\n");
3cf6429a 132 kfree(v9ses);
192eaa28 133 return ERR_PTR(newfid);
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134 }
135
136 sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
137
138 v9fs_fill_super(sb, v9ses, flags);
139
140 inode = v9fs_get_inode(sb, S_IFDIR | mode);
141 if (IS_ERR(inode)) {
142 retval = PTR_ERR(inode);
143 goto put_back_sb;
144 }
145
146 inode->i_uid = uid;
147 inode->i_gid = gid;
148
149 root = d_alloc_root(inode);
150
151 if (!root) {
152 retval = -ENOMEM;
f71626a4 153 goto put_back_sb;
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154 }
155
156 sb->s_root = root;
157
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158 stat_result = v9fs_t_stat(v9ses, newfid, &fcall);
159 if (stat_result < 0) {
160 dprintk(DEBUG_ERROR, "stat error\n");
3cf6429a 161 v9fs_t_clunk(v9ses, newfid);
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162 v9fs_put_idpool(newfid, &v9ses->fidpool);
163 } else {
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164 /* Setup the Root Inode */
165 root_fid = v9fs_fid_create(root, v9ses, newfid, 0);
166 if (root_fid == NULL) {
167 retval = -ENOMEM;
168 goto put_back_sb;
169 }
170
531b1094 171 root_fid->qid = fcall->params.rstat.stat.qid;
9e82cf6a 172 root->d_inode->i_ino =
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173 v9fs_qid2ino(&fcall->params.rstat.stat.qid);
174 v9fs_stat2inode(&fcall->params.rstat.stat, root->d_inode, sb);
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175 }
176
177 kfree(fcall);
178
179 if (stat_result < 0) {
180 retval = stat_result;
f71626a4 181 goto put_back_sb;
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182 }
183
184 return sb;
185
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186put_back_sb:
187 /* deactivate_super calls v9fs_kill_super which will frees the rest */
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188 up_write(&sb->s_umount);
189 deactivate_super(sb);
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190 return ERR_PTR(retval);
191}
192
193/**
194 * v9fs_kill_super - Kill Superblock
195 * @s: superblock
196 *
197 */
198
199static void v9fs_kill_super(struct super_block *s)
200{
201 struct v9fs_session_info *v9ses = s->s_fs_info;
202
203 dprintk(DEBUG_VFS, " %p\n", s);
204
205 v9fs_dentry_release(s->s_root); /* clunk root */
206
207 kill_anon_super(s);
208
209 v9fs_session_close(v9ses);
210 kfree(v9ses);
211 dprintk(DEBUG_VFS, "exiting kill_super\n");
212}
213
214/**
215 * v9fs_show_options - Show mount options in /proc/mounts
216 * @m: seq_file to write to
217 * @mnt: mount descriptor
218 *
219 */
220
221static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
222{
223 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
224
225 if (v9ses->debug != 0)
226 seq_printf(m, ",debug=%u", v9ses->debug);
227 if (v9ses->port != V9FS_PORT)
228 seq_printf(m, ",port=%u", v9ses->port);
229 if (v9ses->maxdata != 9000)
230 seq_printf(m, ",msize=%u", v9ses->maxdata);
231 if (v9ses->afid != ~0)
232 seq_printf(m, ",afid=%u", v9ses->afid);
233 if (v9ses->proto == PROTO_UNIX)
234 seq_puts(m, ",proto=unix");
235 if (v9ses->extended == 0)
236 seq_puts(m, ",noextend");
237 if (v9ses->nodev == 1)
238 seq_puts(m, ",nodevmap");
239 seq_printf(m, ",name=%s", v9ses->name);
240 seq_printf(m, ",aname=%s", v9ses->remotename);
241 seq_printf(m, ",uid=%u", v9ses->uid);
242 seq_printf(m, ",gid=%u", v9ses->gid);
243 return 0;
244}
245
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246static void
247v9fs_umount_begin(struct super_block *sb)
248{
249 struct v9fs_session_info *v9ses = sb->s_fs_info;
250
251 v9fs_session_cancel(v9ses);
252}
253
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254static struct super_operations v9fs_super_ops = {
255 .statfs = simple_statfs,
256 .clear_inode = v9fs_clear_inode,
257 .show_options = v9fs_show_options,
322b329a 258 .umount_begin = v9fs_umount_begin,
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259};
260
261struct file_system_type v9fs_fs_type = {
262 .name = "9P",
263 .get_sb = v9fs_get_sb,
264 .kill_sb = v9fs_kill_super,
265 .owner = THIS_MODULE,
266};