summaryrefslogtreecommitdiffstats
path: root/fs/ocfs2/export.c
blob: b90c751ba9385d8da93589590a9f4243e11b5f8b (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
/* -*- 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 "alloc.h"
#include "dir.h"
#include "dlmglue.h"
#include "dcache.h"
#include "export.h"
#include "inode.h"

#include "buffer_head_io.h"
#include "suballoc.h"

struct ocfs2_inode_handle
{
	u64 ih_blkno;
	u32 ih_generation;
};

static struct dentry *ocfs2_get_dentry(struct super_block *sb,
		struct ocfs2_inode_handle *handle)
{
	struct inode *inode;
	struct ocfs2_super *osb = OCFS2_SB(sb);
	u64 blkno = handle->ih_blkno;
	int status, set;
	struct dentry *result;

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

	if (blkno == 0) {
		mlog(0, "nfs wants inode with blkno: 0\n");
		result = ERR_PTR(-ESTALE);
		goto bail;
	}

	inode = ocfs2_ilookup(sb, blkno);
	/*
	 * If the inode exists in memory, we only need to check it's
	 * generation number
	 */
	if (inode)
		goto check_gen;

	/*
	 * This will synchronize us against ocfs2_delete_inode() on
	 * all nodes
	 */
	status = ocfs2_nfs_sync_lock(osb, 1);
	if (status < 0) {
		mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
		goto check_err;
	}

	status = ocfs2_test_inode_bit(osb, blkno, &set);
	if (status < 0) {
		if (status == -EINVAL) {
			/*
			 * The blkno NFS gave us doesn't even show up
			 * as an inode, we return -ESTALE to be
			 * nice
			 */
			mlog(0, "test inode bit failed %d\n", status);
			status = -ESTALE;
		} else {
			mlog(ML_ERROR, "test inode bit failed %d\n", status);
		}
		goto unlock_nfs_sync;
	}

	/* If the inode allocator bit is clear, this inode must be stale */
	if (!set) {
		mlog(0, "inode %llu suballoc bit is clear\n",
		     (unsigned long long)blkno);
		status = -ESTALE;
		goto unlock_nfs_sync;
	}

	inode = ocfs2_iget(osb, blkno, 0, 0);

unlock_nfs_sync:
	ocfs2_nfs_sync_unlock(osb, 1);

check_err:
	if (status < 0) {
		if (status == -ESTALE) {
			mlog(0, "stale inode ino: %llu generation: %u\n",
			     (unsigned long long)blkno, handle->ih_generation);
		}
		result = ERR_PTR(status);
		goto bail;
	}

	if (IS_ERR(inode)) {
		mlog_errno(PTR_ERR(inode));
		result = (void *)inode;
		goto bail;
	}

check_gen:
	if (handle->ih_generation != inode->i_generation) {
		iput(inode);
		mlog(0, "stale inode ino: %llu generation: %u\n",
		     (unsigned long long)blkno, handle->ih_generation);
		result = ERR_PTR(-ESTALE);
		goto bail;
	}

	result = d_obtain_alias(inode);
	if (IS_ERR(result))
		mlog_errno(PTR_ERR(result));

bail:
	mlog_exit_ptr(result);
	return result;
}

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

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

	status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
	if (status < 0) {
		parent = ERR_PTR(-ENOENT);
		goto bail_unlock;
	}

	parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));

bail_unlock:
	ocfs2_inode_unlock(dir, 0);

bail:
	mlog_exit_ptr(parent);

	return parent;
}

static int ocfs2_encode_fh(struct dentry *dentry, u32 *fh_in, int *max_len,
			   int connectable)
{
	struct inode *inode = dentry->d_inode;
	int len = *max_len;
	int type = 1;
	u64 blkno;
	u32 generation;
	__le32 *fh = (__force __le32 *) fh_in;

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

	if (connectable && (len < 6)) {
		*max_len = 6;
		type = 255;
		goto bail;
	} else if (len < 3) {
		*max_len = 3;
		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_fh_to_dentry(struct super_block *sb,
		struct fid *fid, int fh_len, int fh_type)
{
	struct ocfs2_inode_handle handle;

	if (fh_len < 3 || fh_type > 2)
		return NULL;

	handle.ih_blkno = (u64)le32_to_cpu(fid->raw[0]) << 32;
	handle.ih_blkno |= (u64)le32_to_cpu(fid->raw[1]);
	handle.ih_generation = le32_to_cpu(fid->raw[2]);
	return ocfs2_get_dentry(sb, &handle);
}

static struct dentry *ocfs2_fh_to_parent(struct super_block *sb,
		struct fid *fid, int fh_len, int fh_type)
{
	struct ocfs2_inode_handle parent;

	if (fh_type != 2 || fh_len < 6)
		return NULL;

	parent.ih_blkno = (u64)le32_to_cpu(fid->raw[3]) << 32;
	parent.ih_blkno |= (u64)le32_to_cpu(fid->raw[4]);
	parent.ih_generation = le32_to_cpu(fid->raw[5]);
	return ocfs2_get_dentry(sb, &parent);
}

const struct export_operations ocfs2_export_ops = {
	.encode_fh	= ocfs2_encode_fh,
	.fh_to_dentry	= ocfs2_fh_to_dentry,
	.fh_to_parent	= ocfs2_fh_to_parent,
	.get_parent	= ocfs2_get_parent,
};