tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 <linux/slab.h>
41#include <net/9p/9p.h>
42#include <net/9p/client.h>
43
44#include "v9fs.h"
45#include "v9fs_vfs.h"
46#include "fid.h"
47
48static const struct super_operations v9fs_super_ops;
49
50/**
51 * v9fs_set_super - set the superblock
52 * @s: super block
53 * @data: file system specific data
54 *
55 */
56
57static int v9fs_set_super(struct super_block *s, void *data)
58{
59 s->s_fs_info = data;
60 return set_anon_super(s, data);
61}
62
63/**
64 * v9fs_fill_super - populate superblock with info
65 * @sb: superblock
66 * @v9ses: session information
67 * @flags: flags propagated from v9fs_get_sb()
68 *
69 */
70
71static void
72v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
73 int flags, void *data)
74{
75 sb->s_maxbytes = MAX_LFS_FILESIZE;
76 sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
77 sb->s_blocksize = 1 << sb->s_blocksize_bits;
78 sb->s_magic = V9FS_MAGIC;
79 sb->s_op = &v9fs_super_ops;
80 sb->s_bdi = &v9ses->bdi;
81
82 sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
83 MS_NOATIME;
84
85 save_mount_options(sb, data);
86}
87
88/**
89 * v9fs_get_sb - mount a superblock
90 * @fs_type: file system type
91 * @flags: mount flags
92 * @dev_name: device name that was mounted
93 * @data: mount options
94 * @mnt: mountpoint record to be instantiated
95 *
96 */
97
98static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
99 const char *dev_name, void *data,
100 struct vfsmount *mnt)
101{
102 struct super_block *sb = NULL;
103 struct inode *inode = NULL;
104 struct dentry *root = NULL;
105 struct v9fs_session_info *v9ses = NULL;
106 struct p9_wstat *st = NULL;
107 int mode = S_IRWXUGO | S_ISVTX;
108 struct p9_fid *fid;
109 int retval = 0;
110
111 P9_DPRINTK(P9_DEBUG_VFS, " \n");
112
113 v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
114 if (!v9ses)
115 return -ENOMEM;
116
117 fid = v9fs_session_init(v9ses, dev_name, data);
118 if (IS_ERR(fid)) {
119 retval = PTR_ERR(fid);
120 goto close_session;
121 }
122
123 st = p9_client_stat(fid);
124 if (IS_ERR(st)) {
125 retval = PTR_ERR(st);
126 goto clunk_fid;
127 }
128
129 sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
130 if (IS_ERR(sb)) {
131 retval = PTR_ERR(sb);
132 goto free_stat;
133 }
134 v9fs_fill_super(sb, v9ses, flags, data);
135
136 inode = v9fs_get_inode(sb, S_IFDIR | mode);
137 if (IS_ERR(inode)) {
138 retval = PTR_ERR(inode);
139 goto release_sb;
140 }
141
142 root = d_alloc_root(inode);
143 if (!root) {
144 iput(inode);
145 retval = -ENOMEM;
146 goto release_sb;
147 }
148
149 sb->s_root = root;
150 root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
151
152 v9fs_stat2inode(st, root->d_inode, sb);
153
154 v9fs_fid_add(root, fid);
155 p9stat_free(st);
156 kfree(st);
157
158P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
159 simple_set_mnt(mnt, sb);
160 return 0;
161
162free_stat:
163 p9stat_free(st);
164 kfree(st);
165
166clunk_fid:
167 p9_client_clunk(fid);
168
169close_session:
170 v9fs_session_close(v9ses);
171 kfree(v9ses);
172 return retval;
173
174release_sb:
175 p9stat_free(st);
176 kfree(st);
177 deactivate_locked_super(sb);
178 return retval;
179}
180
181/**
182 * v9fs_kill_super - Kill Superblock
183 * @s: superblock
184 *
185 */
186
187static void v9fs_kill_super(struct super_block *s)
188{
189 struct v9fs_session_info *v9ses = s->s_fs_info;
190
191 P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
192
193 if (s->s_root)
194 v9fs_dentry_release(s->s_root); /* clunk root */
195
196 kill_anon_super(s);
197
198 v9fs_session_cancel(v9ses);
199 v9fs_session_close(v9ses);
200 kfree(v9ses);
201 s->s_fs_info = NULL;
202 P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
203}
204
205static void
206v9fs_umount_begin(struct super_block *sb)
207{
208 struct v9fs_session_info *v9ses;
209
210 v9ses = sb->s_fs_info;
211 v9fs_session_begin_cancel(v9ses);
212}
213
214static const struct super_operations v9fs_super_ops = {
215#ifdef CONFIG_9P_FSCACHE
216 .alloc_inode = v9fs_alloc_inode,
217 .destroy_inode = v9fs_destroy_inode,
218#endif
219 .statfs = simple_statfs,
220 .clear_inode = v9fs_clear_inode,
221 .show_options = generic_show_options,
222 .umount_begin = v9fs_umount_begin,
223};
224
225struct file_system_type v9fs_fs_type = {
226 .name = "9p",
227 .get_sb = v9fs_get_sb,
228 .kill_sb = v9fs_kill_super,
229 .owner = THIS_MODULE,
230};