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 <linux/statfs.h>
42#include <net/9p/9p.h>
43#include <net/9p/client.h>
44
45#include "v9fs.h"
46#include "v9fs_vfs.h"
47#include "fid.h"
48#include "xattr.h"
49
50static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
51
52/**
53 * v9fs_set_super - set the superblock
54 * @s: super block
55 * @data: file system specific data
56 *
57 */
58
59static int v9fs_set_super(struct super_block *s, void *data)
60{
61	s->s_fs_info = data;
62	return set_anon_super(s, data);
63}
64
65/**
66 * v9fs_fill_super - populate superblock with info
67 * @sb: superblock
68 * @v9ses: session information
69 * @flags: flags propagated from v9fs_get_sb()
70 *
71 */
72
73static void
74v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
75		int flags, void *data)
76{
77	sb->s_maxbytes = MAX_LFS_FILESIZE;
78	sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
79	sb->s_blocksize = 1 << sb->s_blocksize_bits;
80	sb->s_magic = V9FS_MAGIC;
81	if (v9fs_proto_dotl(v9ses)) {
82		sb->s_op = &v9fs_super_ops_dotl;
83		sb->s_xattr = v9fs_xattr_handlers;
84	} else
85		sb->s_op = &v9fs_super_ops;
86	sb->s_bdi = &v9ses->bdi;
87
88	sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
89	    MS_NOATIME;
90
91	save_mount_options(sb, data);
92}
93
94/**
95 * v9fs_get_sb - mount a superblock
96 * @fs_type: file system type
97 * @flags: mount flags
98 * @dev_name: device name that was mounted
99 * @data: mount options
100 * @mnt: mountpoint record to be instantiated
101 *
102 */
103
104static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
105		       const char *dev_name, void *data,
106		       struct vfsmount *mnt)
107{
108	struct super_block *sb = NULL;
109	struct inode *inode = NULL;
110	struct dentry *root = NULL;
111	struct v9fs_session_info *v9ses = NULL;
112	int mode = S_IRWXUGO | S_ISVTX;
113	struct p9_fid *fid;
114	int retval = 0;
115
116	P9_DPRINTK(P9_DEBUG_VFS, " \n");
117
118	v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
119	if (!v9ses)
120		return -ENOMEM;
121
122	fid = v9fs_session_init(v9ses, dev_name, data);
123	if (IS_ERR(fid)) {
124		retval = PTR_ERR(fid);
125		/*
126		 * we need to call session_close to tear down some
127		 * of the data structure setup by session_init
128		 */
129		goto close_session;
130	}
131
132	sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
133	if (IS_ERR(sb)) {
134		retval = PTR_ERR(sb);
135		goto clunk_fid;
136	}
137	v9fs_fill_super(sb, v9ses, flags, data);
138
139	inode = v9fs_get_inode(sb, S_IFDIR | mode);
140	if (IS_ERR(inode)) {
141		retval = PTR_ERR(inode);
142		goto release_sb;
143	}
144
145	root = d_alloc_root(inode);
146	if (!root) {
147		iput(inode);
148		retval = -ENOMEM;
149		goto release_sb;
150	}
151	sb->s_root = root;
152
153	if (v9fs_proto_dotl(v9ses)) {
154		struct p9_stat_dotl *st = NULL;
155		st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
156		if (IS_ERR(st)) {
157			retval = PTR_ERR(st);
158			goto release_sb;
159		}
160
161		v9fs_stat2inode_dotl(st, root->d_inode);
162		kfree(st);
163	} else {
164		struct p9_wstat *st = NULL;
165		st = p9_client_stat(fid);
166		if (IS_ERR(st)) {
167			retval = PTR_ERR(st);
168			goto release_sb;
169		}
170
171		root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
172		v9fs_stat2inode(st, root->d_inode, sb);
173
174		p9stat_free(st);
175		kfree(st);
176	}
177
178	v9fs_fid_add(root, fid);
179
180	P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
181	simple_set_mnt(mnt, sb);
182	return 0;
183
184clunk_fid:
185	p9_client_clunk(fid);
186close_session:
187	v9fs_session_close(v9ses);
188	kfree(v9ses);
189	return retval;
190release_sb:
191	/*
192	 * we will do the session_close and root dentry release
193	 * in the below call. But we need to clunk fid, because we haven't
194	 * attached the fid to dentry so it won't get clunked
195	 * automatically.
196	 */
197	p9_client_clunk(fid);
198	deactivate_locked_super(sb);
199	return retval;
200}
201
202/**
203 * v9fs_kill_super - Kill Superblock
204 * @s: superblock
205 *
206 */
207
208static void v9fs_kill_super(struct super_block *s)
209{
210	struct v9fs_session_info *v9ses = s->s_fs_info;
211
212	P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
213
214	if (s->s_root)
215		v9fs_dentry_release(s->s_root);	/* clunk root */
216
217	kill_anon_super(s);
218
219	v9fs_session_cancel(v9ses);
220	v9fs_session_close(v9ses);
221	kfree(v9ses);
222	s->s_fs_info = NULL;
223	P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
224}
225
226static void
227v9fs_umount_begin(struct super_block *sb)
228{
229	struct v9fs_session_info *v9ses;
230
231	v9ses = sb->s_fs_info;
232	v9fs_session_begin_cancel(v9ses);
233}
234
235static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
236{
237	struct v9fs_session_info *v9ses;
238	struct p9_fid *fid;
239	struct p9_rstatfs rs;
240	int res;
241
242	fid = v9fs_fid_lookup(dentry);
243	if (IS_ERR(fid)) {
244		res = PTR_ERR(fid);
245		goto done;
246	}
247
248	v9ses = v9fs_inode2v9ses(dentry->d_inode);
249	if (v9fs_proto_dotl(v9ses)) {
250		res = p9_client_statfs(fid, &rs);
251		if (res == 0) {
252			buf->f_type = rs.type;
253			buf->f_bsize = rs.bsize;
254			buf->f_blocks = rs.blocks;
255			buf->f_bfree = rs.bfree;
256			buf->f_bavail = rs.bavail;
257			buf->f_files = rs.files;
258			buf->f_ffree = rs.ffree;
259			buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL;
260			buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL;
261			buf->f_namelen = rs.namelen;
262		}
263		if (res != -ENOSYS)
264			goto done;
265	}
266	res = simple_statfs(dentry, buf);
267done:
268	return res;
269}
270
271static const struct super_operations v9fs_super_ops = {
272#ifdef CONFIG_9P_FSCACHE
273	.alloc_inode = v9fs_alloc_inode,
274	.destroy_inode = v9fs_destroy_inode,
275#endif
276	.statfs = simple_statfs,
277	.evict_inode = v9fs_evict_inode,
278	.show_options = generic_show_options,
279	.umount_begin = v9fs_umount_begin,
280};
281
282static const struct super_operations v9fs_super_ops_dotl = {
283#ifdef CONFIG_9P_FSCACHE
284	.alloc_inode = v9fs_alloc_inode,
285	.destroy_inode = v9fs_destroy_inode,
286#endif
287	.statfs = v9fs_statfs,
288	.evict_inode = v9fs_evict_inode,
289	.show_options = generic_show_options,
290	.umount_begin = v9fs_umount_begin,
291};
292
293struct file_system_type v9fs_fs_type = {
294	.name = "9p",
295	.get_sb = v9fs_get_sb,
296	.kill_sb = v9fs_kill_super,
297	.owner = THIS_MODULE,
298	.fs_flags = FS_RENAME_DOES_D_MOVE,
299};
300