blob: 5810160d92a8022fe4a8aced3badc59e5277d1d9 [file] [log] [blame]
Mark Fashehccd979b2005-12-15 14:31:24 -08001/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * export.c
5 *
6 * Functions to facilitate NFS exporting
7 *
8 * Copyright (C) 2002, 2005 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
25
26#include <linux/fs.h>
27#include <linux/types.h>
28
29#define MLOG_MASK_PREFIX ML_EXPORT
30#include <cluster/masklog.h>
31
32#include "ocfs2.h"
33
34#include "dir.h"
35#include "dlmglue.h"
36#include "export.h"
37#include "inode.h"
38
39#include "buffer_head_io.h"
40
41struct ocfs2_inode_handle
42{
43 u64 ih_blkno;
44 u32 ih_generation;
45};
46
47static struct dentry *ocfs2_get_dentry(struct super_block *sb, void *vobjp)
48{
49 struct ocfs2_inode_handle *handle = vobjp;
50 struct inode *inode;
51 struct dentry *result;
52
53 mlog_entry("(0x%p, 0x%p)\n", sb, handle);
54
55 if (handle->ih_blkno == 0) {
56 mlog_errno(-ESTALE);
57 return ERR_PTR(-ESTALE);
58 }
59
60 inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno);
61
62 if (IS_ERR(inode)) {
63 mlog_errno(PTR_ERR(inode));
64 return (void *)inode;
65 }
66
67 if (handle->ih_generation != inode->i_generation) {
68 iput(inode);
69 mlog_errno(-ESTALE);
70 return ERR_PTR(-ESTALE);
71 }
72
73 result = d_alloc_anon(inode);
74
75 if (!result) {
76 iput(inode);
77 mlog_errno(-ENOMEM);
78 return ERR_PTR(-ENOMEM);
79 }
80
81 mlog_exit_ptr(result);
82 return result;
83}
84
85static struct dentry *ocfs2_get_parent(struct dentry *child)
86{
87 int status;
88 u64 blkno;
89 struct dentry *parent;
90 struct inode *inode;
91 struct inode *dir = child->d_inode;
92 struct buffer_head *dirent_bh = NULL;
93 struct ocfs2_dir_entry *dirent;
94
95 mlog_entry("(0x%p, '%.*s')\n", child,
96 child->d_name.len, child->d_name.name);
97
98 mlog(0, "find parent of directory %"MLFu64"\n",
99 OCFS2_I(dir)->ip_blkno);
100
101 status = ocfs2_meta_lock(dir, NULL, NULL, 0);
102 if (status < 0) {
103 if (status != -ENOENT)
104 mlog_errno(status);
105 parent = ERR_PTR(status);
106 goto bail;
107 }
108
109 status = ocfs2_find_files_on_disk("..", 2, &blkno, dir, &dirent_bh,
110 &dirent);
111 if (status < 0) {
112 parent = ERR_PTR(-ENOENT);
113 goto bail_unlock;
114 }
115
116 inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno);
117 if (IS_ERR(inode)) {
118 mlog(ML_ERROR, "Unable to create inode %"MLFu64"\n", blkno);
119 parent = ERR_PTR(-EACCES);
120 goto bail_unlock;
121 }
122
123 parent = d_alloc_anon(inode);
124 if (!parent) {
125 iput(inode);
126 parent = ERR_PTR(-ENOMEM);
127 }
128
129bail_unlock:
130 ocfs2_meta_unlock(dir, 0);
131
132 if (dirent_bh)
133 brelse(dirent_bh);
134
135bail:
136 mlog_exit_ptr(parent);
137
138 return parent;
139}
140
141static int ocfs2_encode_fh(struct dentry *dentry, __be32 *fh, int *max_len,
142 int connectable)
143{
144 struct inode *inode = dentry->d_inode;
145 int len = *max_len;
146 int type = 1;
147 u64 blkno;
148 u32 generation;
149
150 mlog_entry("(0x%p, '%.*s', 0x%p, %d, %d)\n", dentry,
151 dentry->d_name.len, dentry->d_name.name,
152 fh, len, connectable);
153
154 if (len < 3 || (connectable && len < 6)) {
155 mlog(ML_ERROR, "fh buffer is too small for encoding\n");
156 type = 255;
157 goto bail;
158 }
159
160 blkno = OCFS2_I(inode)->ip_blkno;
161 generation = inode->i_generation;
162
163 mlog(0, "Encoding fh: blkno: %"MLFu64", generation: %u\n",
164 blkno, generation);
165
166 len = 3;
167 fh[0] = cpu_to_le32((u32)(blkno >> 32));
168 fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff));
169 fh[2] = cpu_to_le32(generation);
170
171 if (connectable && !S_ISDIR(inode->i_mode)) {
172 struct inode *parent;
173
174 spin_lock(&dentry->d_lock);
175
176 parent = dentry->d_parent->d_inode;
177 blkno = OCFS2_I(parent)->ip_blkno;
178 generation = parent->i_generation;
179
180 fh[3] = cpu_to_le32((u32)(blkno >> 32));
181 fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff));
182 fh[5] = cpu_to_le32(generation);
183
184 spin_unlock(&dentry->d_lock);
185
186 len = 6;
187 type = 2;
188
189 mlog(0, "Encoding parent: blkno: %"MLFu64", generation: %u\n",
190 blkno, generation);
191 }
192
193 *max_len = len;
194
195bail:
196 mlog_exit(type);
197 return type;
198}
199
200static struct dentry *ocfs2_decode_fh(struct super_block *sb, __be32 *fh,
201 int fh_len, int fileid_type,
202 int (*acceptable)(void *context,
203 struct dentry *de),
204 void *context)
205{
206 struct ocfs2_inode_handle handle, parent;
207 struct dentry *ret = NULL;
208
209 mlog_entry("(0x%p, 0x%p, %d, %d, 0x%p, 0x%p)\n",
210 sb, fh, fh_len, fileid_type, acceptable, context);
211
212 if (fh_len < 3 || fileid_type > 2)
213 goto bail;
214
215 if (fileid_type == 2) {
216 if (fh_len < 6)
217 goto bail;
218
219 parent.ih_blkno = (u64)le32_to_cpu(fh[3]) << 32;
220 parent.ih_blkno |= (u64)le32_to_cpu(fh[4]);
221 parent.ih_generation = le32_to_cpu(fh[5]);
222
223 mlog(0, "Decoding parent: blkno: %"MLFu64", generation: %u\n",
224 parent.ih_blkno, parent.ih_generation);
225 }
226
227 handle.ih_blkno = (u64)le32_to_cpu(fh[0]) << 32;
228 handle.ih_blkno |= (u64)le32_to_cpu(fh[1]);
229 handle.ih_generation = le32_to_cpu(fh[2]);
230
231 mlog(0, "Encoding fh: blkno: %"MLFu64", generation: %u\n",
232 handle.ih_blkno, handle.ih_generation);
233
234 ret = ocfs2_export_ops.find_exported_dentry(sb, &handle, &parent,
235 acceptable, context);
236
237bail:
238 mlog_exit_ptr(ret);
239 return ret;
240}
241
242struct export_operations ocfs2_export_ops = {
243 .decode_fh = ocfs2_decode_fh,
244 .encode_fh = ocfs2_encode_fh,
245
246 .get_parent = ocfs2_get_parent,
247 .get_dentry = ocfs2_get_dentry,
248};