summaryrefslogtreecommitdiffstats
path: root/fs/9p/vfs_super.c
blob: 124855b3324d7c544eae7fbbe60ff9bfa70c5fcf (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
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  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>
 */

#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/mount.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/statfs.h>
#include <linux/magic.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>

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

static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;

/**
 * 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_mount()
 *
 */

static int
v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
		int flags)
{
	int ret;

	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;
	if (v9fs_proto_dotl(v9ses)) {
		sb->s_op = &v9fs_super_ops_dotl;
		sb->s_xattr = v9fs_xattr_handlers;
	} else {
		sb->s_op = &v9fs_super_ops;
		sb->s_time_max = U32_MAX;
	}

	sb->s_time_min = 0;

	ret = super_setup_bdi(sb);
	if (ret)
		return ret;

	if (v9ses->cache)
		sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;

	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
	if (!v9ses->cache)
		sb->s_flags |= SB_SYNCHRONOUS;

#ifdef CONFIG_9P_FS_POSIX_ACL
	if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL)
		sb->s_flags |= SB_POSIXACL;
#endif

	return 0;
}

/**
 * v9fs_mount - mount a superblock
 * @fs_type: file system type
 * @flags: mount flags
 * @dev_name: device name that was mounted
 * @data: mount options
 *
 */

static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
		       const char *dev_name, void *data)
{
	struct super_block *sb = NULL;
	struct inode *inode = NULL;
	struct dentry *root = NULL;
	struct v9fs_session_info *v9ses = NULL;
	umode_t mode = S_IRWXUGO | S_ISVTX;
	struct p9_fid *fid;
	int retval = 0;

	p9_debug(P9_DEBUG_VFS, "\n");

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

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

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

	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
		sb->s_d_op = &v9fs_cached_dentry_operations;
	else
		sb->s_d_op = &v9fs_dentry_operations;

	inode = v9fs_get_inode(sb, S_IFDIR | mode, 0);
	if (IS_ERR(inode)) {
		retval = PTR_ERR(inode);
		goto release_sb;
	}

	root = d_make_root(inode);
	if (!root) {
		retval = -ENOMEM;
		goto release_sb;
	}
	sb->s_root = root;
	if (v9fs_proto_dotl(v9ses)) {
		struct p9_stat_dotl *st = NULL;
		st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
		if (IS_ERR(st)) {
			retval = PTR_ERR(st);
			goto release_sb;
		}
		d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
		v9fs_stat2inode_dotl(st, d_inode(root), 0);
		kfree(st);
	} else {
		struct p9_wstat *st = NULL;
		st = p9_client_stat(fid);
		if (IS_ERR(st)) {
			retval = PTR_ERR(st);
			goto release_sb;
		}

		d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
		v9fs_stat2inode(st, d_inode(root), sb, 0);

		p9stat_free(st);
		kfree(st);
	}
	retval = v9fs_get_acl(inode, fid);
	if (retval)
		goto release_sb;
	v9fs_fid_add(root, fid);

	p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n");
	return dget(sb->s_root);

clunk_fid:
	p9_client_clunk(fid);
	v9fs_session_close(v9ses);
free_session:
	kfree(v9ses);
	return ERR_PTR(retval);

release_sb:
	/*
	 * we will do the session_close and root dentry release
	 * in the below call. But we need to clunk fid, because we haven't
	 * attached the fid to dentry so it won't get clunked
	 * automatically.
	 */
	p9_client_clunk(fid);
	deactivate_locked_super(sb);
	return ERR_PTR(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_debug(P9_DEBUG_VFS, " %p\n", s);

	kill_anon_super(s);

	v9fs_session_cancel(v9ses);
	v9fs_session_close(v9ses);
	kfree(v9ses);
	s->s_fs_info = NULL;
	p9_debug(P9_DEBUG_VFS, "exiting kill_super\n");
}

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

	v9ses = sb->s_fs_info;
	v9fs_session_begin_cancel(v9ses);
}

static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct v9fs_session_info *v9ses;
	struct p9_fid *fid;
	struct p9_rstatfs rs;
	int res;

	fid = v9fs_fid_lookup(dentry);
	if (IS_ERR(fid)) {
		res = PTR_ERR(fid);
		goto done;
	}

	v9ses = v9fs_dentry2v9ses(dentry);
	if (v9fs_proto_dotl(v9ses)) {
		res = p9_client_statfs(fid, &rs);
		if (res == 0) {
			buf->f_type = rs.type;
			buf->f_bsize = rs.bsize;
			buf->f_blocks = rs.blocks;
			buf->f_bfree = rs.bfree;
			buf->f_bavail = rs.bavail;
			buf->f_files = rs.files;
			buf->f_ffree = rs.ffree;
			buf->f_fsid = u64_to_fsid(rs.fsid);
			buf->f_namelen = rs.namelen;
		}
		if (res != -ENOSYS)
			goto done;
	}
	res = simple_statfs(dentry, buf);
done:
	return res;
}

static int v9fs_drop_inode(struct inode *inode)
{
	struct v9fs_session_info *v9ses;
	v9ses = v9fs_inode2v9ses(inode);
	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
		return generic_drop_inode(inode);
	/*
	 * in case of non cached mode always drop the
	 * the inode because we want the inode attribute
	 * to always match that on the server.
	 */
	return 1;
}

static int v9fs_write_inode(struct inode *inode,
			    struct writeback_control *wbc)
{
	int ret;
	struct p9_wstat wstat;
	struct v9fs_inode *v9inode;
	/*
	 * send an fsync request to server irrespective of
	 * wbc->sync_mode.
	 */
	p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
	v9inode = V9FS_I(inode);
	if (!v9inode->writeback_fid)
		return 0;
	v9fs_blank_wstat(&wstat);

	ret = p9_client_wstat(v9inode->writeback_fid, &wstat);
	if (ret < 0) {
		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
		return ret;
	}
	return 0;
}

static int v9fs_write_inode_dotl(struct inode *inode,
				 struct writeback_control *wbc)
{
	int ret;
	struct v9fs_inode *v9inode;
	/*
	 * send an fsync request to server irrespective of
	 * wbc->sync_mode.
	 */
	v9inode = V9FS_I(inode);
	p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n",
		 __func__, inode, v9inode->writeback_fid);
	if (!v9inode->writeback_fid)
		return 0;

	ret = p9_client_fsync(v9inode->writeback_fid, 0);
	if (ret < 0) {
		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
		return ret;
	}
	return 0;
}

static const struct super_operations v9fs_super_ops = {
	.alloc_inode = v9fs_alloc_inode,
	.free_inode = v9fs_free_inode,
	.statfs = simple_statfs,
	.evict_inode = v9fs_evict_inode,
	.show_options = v9fs_show_options,
	.umount_begin = v9fs_umount_begin,
	.write_inode = v9fs_write_inode,
};

static const struct super_operations v9fs_super_ops_dotl = {
	.alloc_inode = v9fs_alloc_inode,
	.free_inode = v9fs_free_inode,
	.statfs = v9fs_statfs,
	.drop_inode = v9fs_drop_inode,
	.evict_inode = v9fs_evict_inode,
	.show_options = v9fs_show_options,
	.umount_begin = v9fs_umount_begin,
	.write_inode = v9fs_write_inode_dotl,
};

struct file_system_type v9fs_fs_type = {
	.name = "9p",
	.mount = v9fs_mount,
	.kill_sb = v9fs_kill_super,
	.owner = THIS_MODULE,
	.fs_flags = FS_RENAME_DOES_D_MOVE,
};
MODULE_ALIAS_FS("9p");