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 <linux/magic.h>
43#include <net/9p/9p.h>
44#include <net/9p/client.h>
45
46#include "v9fs.h"
47#include "v9fs_vfs.h"
48#include "fid.h"
49#include "xattr.h"
50#include "acl.h"
51
52static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
53
54/**
55 * v9fs_set_super - set the superblock
56 * @s: super block
57 * @data: file system specific data
58 *
59 */
60
61static int v9fs_set_super(struct super_block *s, void *data)
62{
63	s->s_fs_info = data;
64	return set_anon_super(s, data);
65}
66
67/**
68 * v9fs_fill_super - populate superblock with info
69 * @sb: superblock
70 * @v9ses: session information
71 * @flags: flags propagated from v9fs_mount()
72 *
73 */
74
75static void
76v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
77		int flags, void *data)
78{
79	sb->s_maxbytes = MAX_LFS_FILESIZE;
80	sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
81	sb->s_blocksize = 1 << sb->s_blocksize_bits;
82	sb->s_magic = V9FS_MAGIC;
83	if (v9fs_proto_dotl(v9ses)) {
84		sb->s_op = &v9fs_super_ops_dotl;
85		sb->s_xattr = v9fs_xattr_handlers;
86	} else
87		sb->s_op = &v9fs_super_ops;
88	sb->s_bdi = &v9ses->bdi;
89	if (v9ses->cache)
90		sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_CACHE_SIZE;
91
92	sb->s_flags |= MS_ACTIVE | MS_DIRSYNC | MS_NOATIME;
93	if (!v9ses->cache)
94		sb->s_flags |= MS_SYNCHRONOUS;
95
96#ifdef CONFIG_9P_FS_POSIX_ACL
97	if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL)
98		sb->s_flags |= MS_POSIXACL;
99#endif
100
101	save_mount_options(sb, data);
102}
103
104/**
105 * v9fs_mount - mount a superblock
106 * @fs_type: file system type
107 * @flags: mount flags
108 * @dev_name: device name that was mounted
109 * @data: mount options
110 *
111 */
112
113static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
114		       const char *dev_name, void *data)
115{
116	struct super_block *sb = NULL;
117	struct inode *inode = NULL;
118	struct dentry *root = NULL;
119	struct v9fs_session_info *v9ses = NULL;
120	umode_t mode = S_IRWXUGO | S_ISVTX;
121	struct p9_fid *fid;
122	int retval = 0;
123
124	p9_debug(P9_DEBUG_VFS, "\n");
125
126	v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
127	if (!v9ses)
128		return ERR_PTR(-ENOMEM);
129
130	fid = v9fs_session_init(v9ses, dev_name, data);
131	if (IS_ERR(fid)) {
132		retval = PTR_ERR(fid);
133		goto free_session;
134	}
135
136	sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses);
137	if (IS_ERR(sb)) {
138		retval = PTR_ERR(sb);
139		goto clunk_fid;
140	}
141	v9fs_fill_super(sb, v9ses, flags, data);
142
143	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
144		sb->s_d_op = &v9fs_cached_dentry_operations;
145	else
146		sb->s_d_op = &v9fs_dentry_operations;
147
148	inode = v9fs_get_inode(sb, S_IFDIR | mode, 0);
149	if (IS_ERR(inode)) {
150		retval = PTR_ERR(inode);
151		goto release_sb;
152	}
153
154	root = d_make_root(inode);
155	if (!root) {
156		retval = -ENOMEM;
157		goto release_sb;
158	}
159	sb->s_root = root;
160	if (v9fs_proto_dotl(v9ses)) {
161		struct p9_stat_dotl *st = NULL;
162		st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
163		if (IS_ERR(st)) {
164			retval = PTR_ERR(st);
165			goto release_sb;
166		}
167		d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
168		v9fs_stat2inode_dotl(st, d_inode(root));
169		kfree(st);
170	} else {
171		struct p9_wstat *st = NULL;
172		st = p9_client_stat(fid);
173		if (IS_ERR(st)) {
174			retval = PTR_ERR(st);
175			goto release_sb;
176		}
177
178		d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
179		v9fs_stat2inode(st, d_inode(root), sb);
180
181		p9stat_free(st);
182		kfree(st);
183	}
184	retval = v9fs_get_acl(inode, fid);
185	if (retval)
186		goto release_sb;
187	v9fs_fid_add(root, fid);
188
189	p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n");
190	return dget(sb->s_root);
191
192clunk_fid:
193	p9_client_clunk(fid);
194	v9fs_session_close(v9ses);
195free_session:
196	kfree(v9ses);
197	return ERR_PTR(retval);
198
199release_sb:
200	/*
201	 * we will do the session_close and root dentry release
202	 * in the below call. But we need to clunk fid, because we haven't
203	 * attached the fid to dentry so it won't get clunked
204	 * automatically.
205	 */
206	p9_client_clunk(fid);
207	deactivate_locked_super(sb);
208	return ERR_PTR(retval);
209}
210
211/**
212 * v9fs_kill_super - Kill Superblock
213 * @s: superblock
214 *
215 */
216
217static void v9fs_kill_super(struct super_block *s)
218{
219	struct v9fs_session_info *v9ses = s->s_fs_info;
220
221	p9_debug(P9_DEBUG_VFS, " %p\n", s);
222
223	kill_anon_super(s);
224
225	v9fs_session_cancel(v9ses);
226	v9fs_session_close(v9ses);
227	kfree(v9ses);
228	s->s_fs_info = NULL;
229	p9_debug(P9_DEBUG_VFS, "exiting kill_super\n");
230}
231
232static void
233v9fs_umount_begin(struct super_block *sb)
234{
235	struct v9fs_session_info *v9ses;
236
237	v9ses = sb->s_fs_info;
238	v9fs_session_begin_cancel(v9ses);
239}
240
241static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
242{
243	struct v9fs_session_info *v9ses;
244	struct p9_fid *fid;
245	struct p9_rstatfs rs;
246	int res;
247
248	fid = v9fs_fid_lookup(dentry);
249	if (IS_ERR(fid)) {
250		res = PTR_ERR(fid);
251		goto done;
252	}
253
254	v9ses = v9fs_dentry2v9ses(dentry);
255	if (v9fs_proto_dotl(v9ses)) {
256		res = p9_client_statfs(fid, &rs);
257		if (res == 0) {
258			buf->f_type = rs.type;
259			buf->f_bsize = rs.bsize;
260			buf->f_blocks = rs.blocks;
261			buf->f_bfree = rs.bfree;
262			buf->f_bavail = rs.bavail;
263			buf->f_files = rs.files;
264			buf->f_ffree = rs.ffree;
265			buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL;
266			buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL;
267			buf->f_namelen = rs.namelen;
268		}
269		if (res != -ENOSYS)
270			goto done;
271	}
272	res = simple_statfs(dentry, buf);
273done:
274	return res;
275}
276
277static int v9fs_drop_inode(struct inode *inode)
278{
279	struct v9fs_session_info *v9ses;
280	v9ses = v9fs_inode2v9ses(inode);
281	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
282		return generic_drop_inode(inode);
283	/*
284	 * in case of non cached mode always drop the
285	 * the inode because we want the inode attribute
286	 * to always match that on the server.
287	 */
288	return 1;
289}
290
291static int v9fs_write_inode(struct inode *inode,
292			    struct writeback_control *wbc)
293{
294	int ret;
295	struct p9_wstat wstat;
296	struct v9fs_inode *v9inode;
297	/*
298	 * send an fsync request to server irrespective of
299	 * wbc->sync_mode.
300	 */
301	p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
302	v9inode = V9FS_I(inode);
303	if (!v9inode->writeback_fid)
304		return 0;
305	v9fs_blank_wstat(&wstat);
306
307	ret = p9_client_wstat(v9inode->writeback_fid, &wstat);
308	if (ret < 0) {
309		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
310		return ret;
311	}
312	return 0;
313}
314
315static int v9fs_write_inode_dotl(struct inode *inode,
316				 struct writeback_control *wbc)
317{
318	int ret;
319	struct v9fs_inode *v9inode;
320	/*
321	 * send an fsync request to server irrespective of
322	 * wbc->sync_mode.
323	 */
324	v9inode = V9FS_I(inode);
325	p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n",
326		 __func__, inode, v9inode->writeback_fid);
327	if (!v9inode->writeback_fid)
328		return 0;
329
330	ret = p9_client_fsync(v9inode->writeback_fid, 0);
331	if (ret < 0) {
332		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
333		return ret;
334	}
335	return 0;
336}
337
338static const struct super_operations v9fs_super_ops = {
339	.alloc_inode = v9fs_alloc_inode,
340	.destroy_inode = v9fs_destroy_inode,
341	.statfs = simple_statfs,
342	.evict_inode = v9fs_evict_inode,
343	.show_options = generic_show_options,
344	.umount_begin = v9fs_umount_begin,
345	.write_inode = v9fs_write_inode,
346};
347
348static const struct super_operations v9fs_super_ops_dotl = {
349	.alloc_inode = v9fs_alloc_inode,
350	.destroy_inode = v9fs_destroy_inode,
351	.statfs = v9fs_statfs,
352	.drop_inode = v9fs_drop_inode,
353	.evict_inode = v9fs_evict_inode,
354	.show_options = generic_show_options,
355	.umount_begin = v9fs_umount_begin,
356	.write_inode = v9fs_write_inode_dotl,
357};
358
359struct file_system_type v9fs_fs_type = {
360	.name = "9p",
361	.mount = v9fs_mount,
362	.kill_sb = v9fs_kill_super,
363	.owner = THIS_MODULE,
364	.fs_flags = FS_RENAME_DOES_D_MOVE,
365};
366MODULE_ALIAS_FS("9p");
367