1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * export.c
4 *
5 * Functions to facilitate NFS exporting
6 *
7 * Copyright (C) 2002, 2005 Oracle. All rights reserved.
8 */
9
10 #include <linux/fs.h>
11 #include <linux/types.h>
12
13 #include <cluster/masklog.h>
14
15 #include "ocfs2.h"
16
17 #include "alloc.h"
18 #include "dir.h"
19 #include "dlmglue.h"
20 #include "dcache.h"
21 #include "export.h"
22 #include "inode.h"
23
24 #include "buffer_head_io.h"
25 #include "suballoc.h"
26 #include "ocfs2_trace.h"
27
28 struct ocfs2_inode_handle
29 {
30 u64 ih_blkno;
31 u32 ih_generation;
32 };
33
34 static struct dentry *ocfs2_get_dentry(struct super_block *sb,
35 struct ocfs2_inode_handle *handle)
36 {
37 struct inode *inode;
38 struct ocfs2_super *osb = OCFS2_SB(sb);
39 u64 blkno = handle->ih_blkno;
40 int status, set;
41 struct dentry *result;
42
43 trace_ocfs2_get_dentry_begin(sb, handle, (unsigned long long)blkno);
44
45 if (blkno == 0) {
46 result = ERR_PTR(-ESTALE);
47 goto bail;
48 }
49
50 inode = ocfs2_ilookup(sb, blkno);
51 /*
52 * If the inode exists in memory, we only need to check it's
53 * generation number
54 */
55 if (inode)
56 goto check_gen;
57
58 /*
59 * This will synchronize us against ocfs2_delete_inode() on
60 * all nodes
61 */
62 status = ocfs2_nfs_sync_lock(osb, 1);
63 if (status < 0) {
64 mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
65 goto check_err;
66 }
67
68 status = ocfs2_test_inode_bit(osb, blkno, &set);
69 if (status < 0) {
70 if (status == -EINVAL) {
71 /*
72 * The blkno NFS gave us doesn't even show up
73 * as an inode, we return -ESTALE to be
74 * nice
75 */
76 status = -ESTALE;
77 } else
78 mlog(ML_ERROR, "test inode bit failed %d\n", status);
79 goto unlock_nfs_sync;
80 }
81
82 trace_ocfs2_get_dentry_test_bit(status, set);
83 /* If the inode allocator bit is clear, this inode must be stale */
84 if (!set) {
85 status = -ESTALE;
86 goto unlock_nfs_sync;
87 }
88
89 inode = ocfs2_iget(osb, blkno, 0, 0);
90
91 unlock_nfs_sync:
92 ocfs2_nfs_sync_unlock(osb, 1);
93
94 check_err:
95 if (status < 0) {
96 if (status == -ESTALE) {
97 trace_ocfs2_get_dentry_stale((unsigned long long)blkno,
98 handle->ih_generation);
99 }
100 result = ERR_PTR(status);
101 goto bail;
102 }
103
104 if (IS_ERR(inode)) {
105 mlog_errno(PTR_ERR(inode));
106 result = ERR_CAST(inode);
107 goto bail;
108 }
109
110 check_gen:
111 if (handle->ih_generation != inode->i_generation) {
112 trace_ocfs2_get_dentry_generation((unsigned long long)blkno,
113 handle->ih_generation,
114 inode->i_generation);
115 iput(inode);
116 result = ERR_PTR(-ESTALE);
117 goto bail;
118 }
119
120 result = d_obtain_alias(inode);
121 if (IS_ERR(result))
122 mlog_errno(PTR_ERR(result));
123
124 bail:
125 trace_ocfs2_get_dentry_end(result);
126 return result;
127 }
128
129 static struct dentry *ocfs2_get_parent(struct dentry *child)
130 {
131 int status;
132 u64 blkno;
133 struct dentry *parent;
134 struct inode *dir = d_inode(child);
135 int set;
136
137 trace_ocfs2_get_parent(child, child->d_name.len, child->d_name.name,
138 (unsigned long long)OCFS2_I(dir)->ip_blkno);
139
140 status = ocfs2_nfs_sync_lock(OCFS2_SB(dir->i_sb), 1);
141 if (status < 0) {
142 mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
143 parent = ERR_PTR(status);
144 goto bail;
145 }
146
147 status = ocfs2_inode_lock(dir, NULL, 0);
148 if (status < 0) {
149 if (status != -ENOENT)
150 mlog_errno(status);
151 parent = ERR_PTR(status);
152 goto unlock_nfs_sync;
153 }
154
155 status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
156 if (status < 0) {
157 parent = ERR_PTR(-ENOENT);
158 goto bail_unlock;
159 }
160
161 status = ocfs2_test_inode_bit(OCFS2_SB(dir->i_sb), blkno, &set);
162 if (status < 0) {
163 if (status == -EINVAL) {
164 status = -ESTALE;
165 } else
166 mlog(ML_ERROR, "test inode bit failed %d\n", status);
167 parent = ERR_PTR(status);
168 goto bail_unlock;
169 }
170
171 trace_ocfs2_get_dentry_test_bit(status, set);
172 if (!set) {
173 status = -ESTALE;
174 parent = ERR_PTR(status);
175 goto bail_unlock;
176 }
177
178 parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
179
180 bail_unlock:
181 ocfs2_inode_unlock(dir, 0);
182
183 unlock_nfs_sync:
184 ocfs2_nfs_sync_unlock(OCFS2_SB(dir->i_sb), 1);
185
186 bail:
187 trace_ocfs2_get_parent_end(parent);
188
189 return parent;
190 }
191
192 static int ocfs2_encode_fh(struct inode *inode, u32 *fh_in, int *max_len,
193 struct inode *parent)
194 {
195 int len = *max_len;
196 int type = 1;
197 u64 blkno;
198 u32 generation;
199 __le32 *fh = (__force __le32 *) fh_in;
200
201 #ifdef TRACE_HOOKS_ARE_NOT_BRAINDEAD_IN_YOUR_OPINION
202 #error "You go ahead and fix that mess, then. Somehow"
203 trace_ocfs2_encode_fh_begin(dentry, dentry->d_name.len,
204 dentry->d_name.name,
205 fh, len, connectable);
206 #endif
207
208 if (parent && (len < 6)) {
209 *max_len = 6;
210 type = FILEID_INVALID;
211 goto bail;
212 } else if (len < 3) {
213 *max_len = 3;
214 type = FILEID_INVALID;
215 goto bail;
216 }
217
218 blkno = OCFS2_I(inode)->ip_blkno;
219 generation = inode->i_generation;
220
221 trace_ocfs2_encode_fh_self((unsigned long long)blkno, generation);
222
223 len = 3;
224 fh[0] = cpu_to_le32((u32)(blkno >> 32));
225 fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff));
226 fh[2] = cpu_to_le32(generation);
227
228 if (parent) {
229 blkno = OCFS2_I(parent)->ip_blkno;
230 generation = parent->i_generation;
231
232 fh[3] = cpu_to_le32((u32)(blkno >> 32));
233 fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff));
234 fh[5] = cpu_to_le32(generation);
235
236 len = 6;
237 type = 2;
238
239 trace_ocfs2_encode_fh_parent((unsigned long long)blkno,
240 generation);
241 }
242
243 *max_len = len;
244
245 bail:
246 trace_ocfs2_encode_fh_type(type);
247 return type;
248 }
249
250 static struct dentry *ocfs2_fh_to_dentry(struct super_block *sb,
251 struct fid *fid, int fh_len, int fh_type)
252 {
253 struct ocfs2_inode_handle handle;
254
255 if (fh_len < 3 || fh_type > 2)
256 return NULL;
257
258 handle.ih_blkno = (u64)le32_to_cpu((__force __le32)fid->raw[0]) << 32;
259 handle.ih_blkno |= (u64)le32_to_cpu((__force __le32)fid->raw[1]);
260 handle.ih_generation = le32_to_cpu((__force __le32)fid->raw[2]);
261 return ocfs2_get_dentry(sb, &handle);
262 }
263
264 static struct dentry *ocfs2_fh_to_parent(struct super_block *sb,
265 struct fid *fid, int fh_len, int fh_type)
266 {
267 struct ocfs2_inode_handle parent;
268
269 if (fh_type != 2 || fh_len < 6)
270 return NULL;
271
272 parent.ih_blkno = (u64)le32_to_cpu((__force __le32)fid->raw[3]) << 32;
273 parent.ih_blkno |= (u64)le32_to_cpu((__force __le32)fid->raw[4]);
274 parent.ih_generation = le32_to_cpu((__force __le32)fid->raw[5]);
275 return ocfs2_get_dentry(sb, &parent);
276 }
277
278 const struct export_operations ocfs2_export_ops = {
279 .encode_fh = ocfs2_encode_fh,
280 .fh_to_dentry = ocfs2_fh_to_dentry,
281 .fh_to_parent = ocfs2_fh_to_parent,
282 .get_parent = ocfs2_get_parent,
283 .flags = EXPORT_OP_ASYNC_LOCK,
284 };
285
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