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 version 2
12 * as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to:
21 * Free Software Foundation
22 * 51 Franklin Street, Fifth Floor
23 * Boston, MA 02111-1301 USA
24 *
25 */
26
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/fs.h>
31 #include <linux/file.h>
32 #include <linux/stat.h>
33 #include <linux/string.h>
34 #include <linux/inet.h>
35 #include <linux/pagemap.h>
36 #include <linux/seq_file.h>
37 #include <linux/mount.h>
38 #include <linux/idr.h>
39 #include <linux/sched.h>
40 #include <net/9p/9p.h>
41 #include <net/9p/client.h>
42
43 #include "v9fs.h"
44 #include "v9fs_vfs.h"
45 #include "fid.h"
46
47 static void v9fs_clear_inode(struct inode *);
48 static const struct super_operations v9fs_super_ops;
49
50 /**
51 * v9fs_clear_inode - release an inode
52 * @inode: inode to release
53 *
54 */
55
56 static void v9fs_clear_inode(struct inode *inode)
57 {
58 filemap_fdatawrite(inode->i_mapping);
59 }
60
61 /**
62 * v9fs_set_super - set the superblock
63 * @s: super block
64 * @data: file system specific data
65 *
66 */
67
68 static int v9fs_set_super(struct super_block *s, void *data)
69 {
70 s->s_fs_info = data;
71 return set_anon_super(s, data);
72 }
73
74 /**
75 * v9fs_fill_super - populate superblock with info
76 * @sb: superblock
77 * @v9ses: session information
78 *
79 */
80
81 static void
82 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
83 int flags)
84 {
85 sb->s_maxbytes = MAX_LFS_FILESIZE;
86 sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
87 sb->s_blocksize = 1 << sb->s_blocksize_bits;
88 sb->s_magic = V9FS_MAGIC;
89 sb->s_op = &v9fs_super_ops;
90
91 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
92 MS_NOATIME;
93 }
94
95 /**
96 * v9fs_get_sb - mount a superblock
97 * @fs_type: file system type
98 * @flags: mount flags
99 * @dev_name: device name that was mounted
100 * @data: mount options
101 * @mnt: mountpoint record to be instantiated
102 *
103 */
104
105 static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
106 const char *dev_name, void *data,
107 struct vfsmount *mnt)
108 {
109 struct super_block *sb = NULL;
110 struct inode *inode = NULL;
111 struct dentry *root = NULL;
112 struct v9fs_session_info *v9ses = NULL;
113 struct p9_stat *st = NULL;
114 int mode = S_IRWXUGO | S_ISVTX;
115 uid_t uid = current->fsuid;
116 gid_t gid = current->fsgid;
117 struct p9_fid *fid;
118 int retval = 0;
119
120 P9_DPRINTK(P9_DEBUG_VFS, " \n");
121
122 st = NULL;
123 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
124 if (!v9ses)
125 return -ENOMEM;
126
127 fid = v9fs_session_init(v9ses, dev_name, data);
128 if (IS_ERR(fid)) {
129 retval = PTR_ERR(fid);
130 fid = NULL;
131 kfree(v9ses);
132 v9ses = NULL;
133 goto error;
134 }
135
136 st = p9_client_stat(fid);
137 if (IS_ERR(st)) {
138 retval = PTR_ERR(st);
139 goto error;
140 }
141
142 sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
143 if (IS_ERR(sb)) {
144 retval = PTR_ERR(sb);
145 goto error;
146 }
147 v9fs_fill_super(sb, v9ses, flags);
148
149 inode = v9fs_get_inode(sb, S_IFDIR | mode);
150 if (IS_ERR(inode)) {
151 retval = PTR_ERR(inode);
152 goto error;
153 }
154
155 inode->i_uid = uid;
156 inode->i_gid = gid;
157
158 root = d_alloc_root(inode);
159 if (!root) {
160 retval = -ENOMEM;
161 goto error;
162 }
163
164 sb->s_root = root;
165 root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
166 v9fs_stat2inode(st, root->d_inode, sb);
167 v9fs_fid_add(root, fid);
168 kfree(st);
169
170 return simple_set_mnt(mnt, sb);
171
172 error:
173 kfree(st);
174 if (fid)
175 p9_client_clunk(fid);
176
177 if (v9ses) {
178 v9fs_session_close(v9ses);
179 kfree(v9ses);
180 }
181
182 if (sb) {
183 up_write(&sb->s_umount);
184 deactivate_super(sb);
185 }
186
187 return retval;
188 }
189
190 /**
191 * v9fs_kill_super - Kill Superblock
192 * @s: superblock
193 *
194 */
195
196 static void v9fs_kill_super(struct super_block *s)
197 {
198 struct v9fs_session_info *v9ses = s->s_fs_info;
199
200 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
201
202 v9fs_dentry_release(s->s_root); /* clunk root */
203
204 kill_anon_super(s);
205
206 v9fs_session_close(v9ses);
207 kfree(v9ses);
208 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
209 }
210
211 /**
212 * v9fs_show_options - Show mount options in /proc/mounts
213 * @m: seq_file to write to
214 * @mnt: mount descriptor
215 *
216 */
217
218 static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
219 {
220 struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
221
222 seq_printf(m, "%s", v9ses->options);
223 return 0;
224 }
225
226 static void
227 v9fs_umount_begin(struct vfsmount *vfsmnt, int flags)
228 {
229 struct v9fs_session_info *v9ses = vfsmnt->mnt_sb->s_fs_info;
230
231 if (flags & MNT_FORCE)
232 v9fs_session_cancel(v9ses);
233 }
234
235 static const struct super_operations v9fs_super_ops = {
236 .statfs = simple_statfs,
237 .clear_inode = v9fs_clear_inode,
238 .show_options = v9fs_show_options,
239 .umount_begin = v9fs_umount_begin,
240 };
241
242 struct file_system_type v9fs_fs_type = {
243 .name = "9p",
244 .get_sb = v9fs_get_sb,
245 .kill_sb = v9fs_kill_super,
246 .owner = THIS_MODULE,
247 };
248
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