1 /* -*- 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 #include <cluster/masklog.h>
30
31 #include "ocfs2.h"
32
33 #include "alloc.h"
34 #include "dir.h"
35 #include "dlmglue.h"
36 #include "dcache.h"
37 #include "export.h"
38 #include "inode.h"
39
40 #include "buffer_head_io.h"
41 #include "suballoc.h"
42 #include "ocfs2_trace.h"
43
44 struct ocfs2_inode_handle
45 {
46 u64 ih_blkno;
47 u32 ih_generation;
48 };
49
ocfs2_get_dentry(struct super_block * sb,struct ocfs2_inode_handle * handle)50 static struct dentry *ocfs2_get_dentry(struct super_block *sb,
51 struct ocfs2_inode_handle *handle)
52 {
53 struct inode *inode;
54 struct ocfs2_super *osb = OCFS2_SB(sb);
55 u64 blkno = handle->ih_blkno;
56 int status, set;
57 struct dentry *result;
58
59 trace_ocfs2_get_dentry_begin(sb, handle, (unsigned long long)blkno);
60
61 if (blkno == 0) {
62 result = ERR_PTR(-ESTALE);
63 goto bail;
64 }
65
66 inode = ocfs2_ilookup(sb, blkno);
67 /*
68 * If the inode exists in memory, we only need to check it's
69 * generation number
70 */
71 if (inode)
72 goto check_gen;
73
74 /*
75 * This will synchronize us against ocfs2_delete_inode() on
76 * all nodes
77 */
78 status = ocfs2_nfs_sync_lock(osb, 1);
79 if (status < 0) {
80 mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
81 goto check_err;
82 }
83
84 status = ocfs2_test_inode_bit(osb, blkno, &set);
85 trace_ocfs2_get_dentry_test_bit(status, set);
86 if (status < 0) {
87 if (status == -EINVAL) {
88 /*
89 * The blkno NFS gave us doesn't even show up
90 * as an inode, we return -ESTALE to be
91 * nice
92 */
93 status = -ESTALE;
94 } else
95 mlog(ML_ERROR, "test inode bit failed %d\n", status);
96 goto unlock_nfs_sync;
97 }
98
99 /* If the inode allocator bit is clear, this inode must be stale */
100 if (!set) {
101 status = -ESTALE;
102 goto unlock_nfs_sync;
103 }
104
105 inode = ocfs2_iget(osb, blkno, 0, 0);
106
107 unlock_nfs_sync:
108 ocfs2_nfs_sync_unlock(osb, 1);
109
110 check_err:
111 if (status < 0) {
112 if (status == -ESTALE) {
113 trace_ocfs2_get_dentry_stale((unsigned long long)blkno,
114 handle->ih_generation);
115 }
116 result = ERR_PTR(status);
117 goto bail;
118 }
119
120 if (IS_ERR(inode)) {
121 mlog_errno(PTR_ERR(inode));
122 result = (void *)inode;
123 goto bail;
124 }
125
126 check_gen:
127 if (handle->ih_generation != inode->i_generation) {
128 iput(inode);
129 trace_ocfs2_get_dentry_generation((unsigned long long)blkno,
130 handle->ih_generation,
131 inode->i_generation);
132 result = ERR_PTR(-ESTALE);
133 goto bail;
134 }
135
136 result = d_obtain_alias(inode);
137 if (IS_ERR(result))
138 mlog_errno(PTR_ERR(result));
139
140 bail:
141 trace_ocfs2_get_dentry_end(result);
142 return result;
143 }
144
ocfs2_get_parent(struct dentry * child)145 static struct dentry *ocfs2_get_parent(struct dentry *child)
146 {
147 int status;
148 u64 blkno;
149 struct dentry *parent;
150 struct inode *dir = child->d_inode;
151
152 trace_ocfs2_get_parent(child, child->d_name.len, child->d_name.name,
153 (unsigned long long)OCFS2_I(dir)->ip_blkno);
154
155 status = ocfs2_inode_lock(dir, NULL, 0);
156 if (status < 0) {
157 if (status != -ENOENT)
158 mlog_errno(status);
159 parent = ERR_PTR(status);
160 goto bail;
161 }
162
163 status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
164 if (status < 0) {
165 parent = ERR_PTR(-ENOENT);
166 goto bail_unlock;
167 }
168
169 parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
170
171 bail_unlock:
172 ocfs2_inode_unlock(dir, 0);
173
174 bail:
175 trace_ocfs2_get_parent_end(parent);
176
177 return parent;
178 }
179
ocfs2_encode_fh(struct inode * inode,u32 * fh_in,int * max_len,struct inode * parent)180 static int ocfs2_encode_fh(struct inode *inode, u32 *fh_in, int *max_len,
181 struct inode *parent)
182 {
183 int len = *max_len;
184 int type = 1;
185 u64 blkno;
186 u32 generation;
187 __le32 *fh = (__force __le32 *) fh_in;
188
189 #ifdef TRACE_HOOKS_ARE_NOT_BRAINDEAD_IN_YOUR_OPINION
190 #error "You go ahead and fix that mess, then. Somehow"
191 trace_ocfs2_encode_fh_begin(dentry, dentry->d_name.len,
192 dentry->d_name.name,
193 fh, len, connectable);
194 #endif
195
196 if (parent && (len < 6)) {
197 *max_len = 6;
198 type = FILEID_INVALID;
199 goto bail;
200 } else if (len < 3) {
201 *max_len = 3;
202 type = FILEID_INVALID;
203 goto bail;
204 }
205
206 blkno = OCFS2_I(inode)->ip_blkno;
207 generation = inode->i_generation;
208
209 trace_ocfs2_encode_fh_self((unsigned long long)blkno, generation);
210
211 len = 3;
212 fh[0] = cpu_to_le32((u32)(blkno >> 32));
213 fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff));
214 fh[2] = cpu_to_le32(generation);
215
216 if (parent) {
217 blkno = OCFS2_I(parent)->ip_blkno;
218 generation = parent->i_generation;
219
220 fh[3] = cpu_to_le32((u32)(blkno >> 32));
221 fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff));
222 fh[5] = cpu_to_le32(generation);
223
224 len = 6;
225 type = 2;
226
227 trace_ocfs2_encode_fh_parent((unsigned long long)blkno,
228 generation);
229 }
230
231 *max_len = len;
232
233 bail:
234 trace_ocfs2_encode_fh_type(type);
235 return type;
236 }
237
ocfs2_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)238 static struct dentry *ocfs2_fh_to_dentry(struct super_block *sb,
239 struct fid *fid, int fh_len, int fh_type)
240 {
241 struct ocfs2_inode_handle handle;
242
243 if (fh_len < 3 || fh_type > 2)
244 return NULL;
245
246 handle.ih_blkno = (u64)le32_to_cpu(fid->raw[0]) << 32;
247 handle.ih_blkno |= (u64)le32_to_cpu(fid->raw[1]);
248 handle.ih_generation = le32_to_cpu(fid->raw[2]);
249 return ocfs2_get_dentry(sb, &handle);
250 }
251
ocfs2_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)252 static struct dentry *ocfs2_fh_to_parent(struct super_block *sb,
253 struct fid *fid, int fh_len, int fh_type)
254 {
255 struct ocfs2_inode_handle parent;
256
257 if (fh_type != 2 || fh_len < 6)
258 return NULL;
259
260 parent.ih_blkno = (u64)le32_to_cpu(fid->raw[3]) << 32;
261 parent.ih_blkno |= (u64)le32_to_cpu(fid->raw[4]);
262 parent.ih_generation = le32_to_cpu(fid->raw[5]);
263 return ocfs2_get_dentry(sb, &parent);
264 }
265
266 const struct export_operations ocfs2_export_ops = {
267 .encode_fh = ocfs2_encode_fh,
268 .fh_to_dentry = ocfs2_fh_to_dentry,
269 .fh_to_parent = ocfs2_fh_to_parent,
270 .get_parent = ocfs2_get_parent,
271 };
272