summaryrefslogtreecommitdiffstats
path: root/fs/ocfs2/export.c
blob: ffcd79749e0d21d5faf05b8d122e93280076add5 (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
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * export.c
 *
 * Functions to facilitate NFS exporting
 *
 * Copyright (C) 2002, 2005 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/types.h>

#define MLOG_MASK_PREFIX ML_EXPORT
#include <cluster/masklog.h>

#include "ocfs2.h"

#include "dir.h"
#include "dlmglue.h"
#include "dcache.h"
#include "export.h"
#include "inode.h"

#include "buffer_head_io.h"

struct ocfs2_inode_handle
{
	u64 ih_blkno;
	u32 ih_generation;
};

static struct dentry *ocfs2_get_dentry(struct super_block *sb, void *vobjp)
{
	struct ocfs2_inode_handle *handle = vobjp;
	struct inode *inode;
	struct dentry *result;

	mlog_entry("(0x%p, 0x%p)\n", sb, handle);

	if (handle->ih_blkno == 0) {
		mlog_errno(-ESTALE);
		return ERR_PTR(-ESTALE);
	}

	inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno);

	if (IS_ERR(inode)) {
		mlog_errno(PTR_ERR(inode));
		return (void *)inode;
	}

	if (handle->ih_generation != inode->i_generation) {
		iput(inode);
		mlog_errno(-ESTALE);
		return ERR_PTR(-ESTALE);
	}

	result = d_alloc_anon(inode);

	if (!result) {
		iput(inode);
		mlog_errno(-ENOMEM);
		return ERR_PTR(-ENOMEM);
	}
	result->d_op = &ocfs2_dentry_ops;

	mlog_exit_ptr(result);
	return result;
}

static struct dentry *ocfs2_get_parent(struct dentry *child)
{
	int status;
	u64 blkno;
	struct dentry *parent;
	struct inode *inode;
	struct inode *dir = child->d_inode;
	struct buffer_head *dirent_bh = NULL;
	struct ocfs2_dir_entry *dirent;

	mlog_entry("(0x%p, '%.*s')\n", child,
		   child->d_name.len, child->d_name.name);

	mlog(0, "find parent of directory %llu\n",
	     (unsigned long long)OCFS2_I(dir)->ip_blkno);

	status = ocfs2_meta_lock(dir, NULL, NULL, 0);
	if (status < 0) {
		if (status != -ENOENT)
			mlog_errno(status);
		parent = ERR_PTR(status);
		goto bail;
	}

	status = ocfs2_find_files_on_disk("..", 2, &blkno, dir, &dirent_bh,
					  &dirent);
	if (status < 0) {
		parent = ERR_PTR(-ENOENT);
		goto bail_unlock;
	}

	inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno);
	if (IS_ERR(inode)) {
		mlog(ML_ERROR, "Unable to create inode %llu\n",
		     (unsigned long long)blkno);
		parent = ERR_PTR(-EACCES);
		goto bail_unlock;
	}

	parent = d_alloc_anon(inode);
	if (!parent) {
		iput(inode);
		parent = ERR_PTR(-ENOMEM);
	}

	parent->d_op = &ocfs2_dentry_ops;

bail_unlock:
	ocfs2_meta_unlock(dir, 0);

	if (dirent_bh)
		brelse(dirent_bh);

bail:
	mlog_exit_ptr(parent);

	return parent;
}

static int ocfs2_encode_fh(struct dentry *dentry, __be32 *fh, int *max_len,
			   int connectable)
{
	struct inode *inode = dentry->d_inode;
	int len = *max_len;
	int type = 1;
	u64 blkno;
	u32 generation;

	mlog_entry("(0x%p, '%.*s', 0x%p, %d, %d)\n", dentry,
		   dentry->d_name.len, dentry->d_name.name,
		   fh, len, connectable);

	if (len < 3 || (connectable && len < 6)) {
		mlog(ML_ERROR, "fh buffer is too small for encoding\n");
		type = 255;
		goto bail;
	}

	blkno = OCFS2_I(inode)->ip_blkno;
	generation = inode->i_generation;

	mlog(0, "Encoding fh: blkno: %llu, generation: %u\n",
	     (unsigned long long)blkno, generation);

	len = 3;
	fh[0] = cpu_to_le32((u32)(blkno >> 32));
	fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff));
	fh[2] = cpu_to_le32(generation);

	if (connectable && !S_ISDIR(inode->i_mode)) {
		struct inode *parent;

		spin_lock(&dentry->d_lock);

		parent = dentry->d_parent->d_inode;
		blkno = OCFS2_I(parent)->ip_blkno;
		generation = parent->i_generation;

		fh[3] = cpu_to_le32((u32)(blkno >> 32));
		fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff));
		fh[5] = cpu_to_le32(generation);

		spin_unlock(&dentry->d_lock);

		len = 6;
		type = 2;

		mlog(0, "Encoding parent: blkno: %llu, generation: %u\n",
		     (unsigned long long)blkno, generation);
	}
	
	*max_len = len;

bail:
	mlog_exit(type);
	return type;
}

static struct dentry *ocfs2_decode_fh(struct super_block *sb, __be32 *fh,
				      int fh_len, int fileid_type,
				      int (*acceptable)(void *context,
						        struct dentry *de),
				      void *context)
{
	struct ocfs2_inode_handle handle, parent;
	struct dentry *ret = NULL;

	mlog_entry("(0x%p, 0x%p, %d, %d, 0x%p, 0x%p)\n",
		   sb, fh, fh_len, fileid_type, acceptable, context);

	if (fh_len < 3 || fileid_type > 2)
		goto bail;

	if (fileid_type == 2) {
		if (fh_len < 6)
			goto bail;

		parent.ih_blkno = (u64)le32_to_cpu(fh[3]) << 32;
		parent.ih_blkno |= (u64)le32_to_cpu(fh[4]);
		parent.ih_generation = le32_to_cpu(fh[5]);

		mlog(0, "Decoding parent: blkno: %llu, generation: %u\n",
		     (unsigned long long)parent.ih_blkno,
		     parent.ih_generation);
	}

	handle.ih_blkno = (u64)le32_to_cpu(fh[0]) << 32;
	handle.ih_blkno |= (u64)le32_to_cpu(fh[1]);
	handle.ih_generation = le32_to_cpu(fh[2]);

	mlog(0, "Encoding fh: blkno: %llu, generation: %u\n",
	     (unsigned long long)handle.ih_blkno, handle.ih_generation);

	ret = ocfs2_export_ops.find_exported_dentry(sb, &handle, &parent,
						    acceptable, context);

bail:
	mlog_exit_ptr(ret);
	return ret;
}

struct export_operations ocfs2_export_ops = {
	.decode_fh	= ocfs2_decode_fh,
	.encode_fh	= ocfs2_encode_fh,

	.get_parent	= ocfs2_get_parent,
	.get_dentry	= ocfs2_get_dentry,
};