aboutsummaryrefslogtreecommitdiffstats
path: root/fs/9p/vfs_super.c
blob: 072dce0944774473a62ebaa3b16b58f3949956aa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
/*
 *  linux/fs/9p/vfs_super.c
 *
 * This file contians superblock ops for 9P2000. It is intended that
 * you mount this file system on directories.
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>

#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"

static void v9fs_clear_inode(struct inode *);
static const struct super_operations v9fs_super_ops;

/**
 * v9fs_clear_inode - release an inode
 * @inode: inode to release
 *
 */

static void v9fs_clear_inode(struct inode *inode)
{
	filemap_fdatawrite(inode->i_mapping);
}

/**
 * v9fs_set_super - set the superblock
 * @s: super block
 * @data: file system specific data
 *
 */

static int v9fs_set_super(struct super_block *s, void *data)
{
	s->s_fs_info = data;
	return set_anon_super(s, data);
}

/**
 * v9fs_fill_super - populate superblock with info
 * @sb: superblock
 * @v9ses: session information
 * @flags: flags propagated from v9fs_get_sb()
 *
 */

static void
v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
		int flags)
{
	sb->s_maxbytes = MAX_LFS_FILESIZE;
	sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
	sb->s_blocksize = 1 << sb->s_blocksize_bits;
	sb->s_magic = V9FS_MAGIC;
	sb->s_op = &v9fs_super_ops;

	sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
	    MS_NOATIME;
}

/**
 * v9fs_get_sb - mount a superblock
 * @fs_type: file system type
 * @flags: mount flags
 * @dev_name: device name that was mounted
 * @data: mount options
 * @mnt: mountpoint record to be instantiated
 *
 */

static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
		       const char *dev_name, void *data,
		       struct vfsmount *mnt)
{
	struct super_block *sb = NULL;
	struct inode *inode = NULL;
	struct dentry *root = NULL;
	struct v9fs_session_info *v9ses = NULL;
	struct p9_wstat *st = NULL;
	int mode = S_IRWXUGO | S_ISVTX;
	struct p9_fid *fid;
	int retval = 0;

	P9_DPRINTK(P9_DEBUG_VFS, " \n");

	v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
	if (!v9ses)
		return -ENOMEM;

	fid = v9fs_session_init(v9ses, dev_name, data);
	if (IS_ERR(fid)) {
		retval = PTR_ERR(fid);
		goto close_session;
	}

	st = p9_client_stat(fid);
	if (IS_ERR(st)) {
		retval = PTR_ERR(st);
		goto clunk_fid;
	}

	sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
	if (IS_ERR(sb)) {
		retval = PTR_ERR(sb);
		goto free_stat;
	}
	v9fs_fill_super(sb, v9ses, flags);

	inode = v9fs_get_inode(sb, S_IFDIR | mode);
	if (IS_ERR(inode)) {
		retval = PTR_ERR(inode);
		goto release_sb;
	}

	root = d_alloc_root(inode);
	if (!root) {
		iput(inode);
		retval = -ENOMEM;
		goto release_sb;
	}

	sb->s_root = root;
	root->d_inode->i_ino = v9fs_qid2ino(&st->qid);

	v9fs_stat2inode(st, root->d_inode, sb);

	v9fs_fid_add(root, fid);
	p9stat_free(st);
	kfree(st);

P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
	simple_set_mnt(mnt, sb);
	return 0;

free_stat:
	p9stat_free(st);
	kfree(st);

clunk_fid:
	p9_client_clunk(fid);

close_session:
	v9fs_session_close(v9ses);
	kfree(v9ses);
	return retval;

release_sb:
	p9stat_free(st);
	kfree(st);
	deactivate_locked_super(sb);
	return retval;
}

/**
 * v9fs_kill_super - Kill Superblock
 * @s: superblock
 *
 */

static void v9fs_kill_super(struct super_block *s)
{
	struct v9fs_session_info *v9ses = s->s_fs_info;

	P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);

	v9fs_dentry_release(s->s_root);	/* clunk root */

	kill_anon_super(s);

	v9fs_session_close(v9ses);
	kfree(v9ses);
	s->s_fs_info = NULL;
	P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
}

/**
 * v9fs_show_options - Show mount options in /proc/mounts
 * @m: seq_file to write to
 * @mnt: mount descriptor
 *
 */

static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
{
	struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
	if (v9ses->options != NULL)
		seq_printf(m, ",%s", v9ses->options);
	return 0;
}

static void
v9fs_umount_begin(struct super_block *sb)
{
	struct v9fs_session_info *v9ses;

	v9ses = sb->s_fs_info;
	v9fs_session_cancel(v9ses);
}

static const struct super_operations v9fs_super_ops = {
	.statfs = simple_statfs,
	.clear_inode = v9fs_clear_inode,
	.show_options = v9fs_show_options,
	.umount_begin = v9fs_umount_begin,
};

struct file_system_type v9fs_fs_type = {
	.name = "9p",
	.get_sb = v9fs_get_sb,
	.kill_sb = v9fs_kill_super,
	.owner = THIS_MODULE,
};