1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * export.c
6 *
7 * Functions to facilitate NFS exporting
8 *
9 * Copyright (C) 2002, 2005 Oracle. All rights reserved.
10 */
11
12 #include <linux/fs.h>
13 #include <linux/types.h>
14
15 #include <cluster/masklog.h>
16
17 #include "ocfs2.h"
18
19 #include "alloc.h"
20 #include "dir.h"
21 #include "dlmglue.h"
22 #include "dcache.h"
23 #include "export.h"
24 #include "inode.h"
25
26 #include "buffer_head_io.h"
27 #include "suballoc.h"
28 #include "ocfs2_trace.h"
29
30 struct ocfs2_inode_handle
31 {
32 u64 ih_blkno;
33 u32 ih_generation;
34 };
35
ocfs2_get_dentry(struct super_block * sb,struct ocfs2_inode_handle * handle)36 static struct dentry *ocfs2_get_dentry(struct super_block *sb,
37 struct ocfs2_inode_handle *handle)
38 {
39 struct inode *inode;
40 struct ocfs2_super *osb = OCFS2_SB(sb);
41 u64 blkno = handle->ih_blkno;
42 int status, set;
43 struct dentry *result;
44
45 trace_ocfs2_get_dentry_begin(sb, handle, (unsigned long long)blkno);
46
47 if (blkno == 0) {
48 result = ERR_PTR(-ESTALE);
49 goto bail;
50 }
51
52 inode = ocfs2_ilookup(sb, blkno);
53 /*
54 * If the inode exists in memory, we only need to check it's
55 * generation number
56 */
57 if (inode)
58 goto check_gen;
59
60 /*
61 * This will synchronize us against ocfs2_delete_inode() on
62 * all nodes
63 */
64 status = ocfs2_nfs_sync_lock(osb, 1);
65 if (status < 0) {
66 mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
67 goto check_err;
68 }
69
70 status = ocfs2_test_inode_bit(osb, blkno, &set);
71 if (status < 0) {
72 if (status == -EINVAL) {
73 /*
74 * The blkno NFS gave us doesn't even show up
75 * as an inode, we return -ESTALE to be
76 * nice
77 */
78 status = -ESTALE;
79 } else
80 mlog(ML_ERROR, "test inode bit failed %d\n", status);
81 goto unlock_nfs_sync;
82 }
83
84 trace_ocfs2_get_dentry_test_bit(status, set);
85 /* If the inode allocator bit is clear, this inode must be stale */
86 if (!set) {
87 status = -ESTALE;
88 goto unlock_nfs_sync;
89 }
90
91 inode = ocfs2_iget(osb, blkno, 0, 0);
92
93 unlock_nfs_sync:
94 ocfs2_nfs_sync_unlock(osb, 1);
95
96 check_err:
97 if (status < 0) {
98 if (status == -ESTALE) {
99 trace_ocfs2_get_dentry_stale((unsigned long long)blkno,
100 handle->ih_generation);
101 }
102 result = ERR_PTR(status);
103 goto bail;
104 }
105
106 if (IS_ERR(inode)) {
107 mlog_errno(PTR_ERR(inode));
108 result = ERR_CAST(inode);
109 goto bail;
110 }
111
112 check_gen:
113 if (handle->ih_generation != inode->i_generation) {
114 trace_ocfs2_get_dentry_generation((unsigned long long)blkno,
115 handle->ih_generation,
116 inode->i_generation);
117 iput(inode);
118 result = ERR_PTR(-ESTALE);
119 goto bail;
120 }
121
122 result = d_obtain_alias(inode);
123 if (IS_ERR(result))
124 mlog_errno(PTR_ERR(result));
125
126 bail:
127 trace_ocfs2_get_dentry_end(result);
128 return result;
129 }
130
ocfs2_get_parent(struct dentry * child)131 static struct dentry *ocfs2_get_parent(struct dentry *child)
132 {
133 int status;
134 u64 blkno;
135 struct dentry *parent;
136 struct inode *dir = d_inode(child);
137 int set;
138
139 trace_ocfs2_get_parent(child, child->d_name.len, child->d_name.name,
140 (unsigned long long)OCFS2_I(dir)->ip_blkno);
141
142 status = ocfs2_nfs_sync_lock(OCFS2_SB(dir->i_sb), 1);
143 if (status < 0) {
144 mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
145 parent = ERR_PTR(status);
146 goto bail;
147 }
148
149 status = ocfs2_inode_lock(dir, NULL, 0);
150 if (status < 0) {
151 if (status != -ENOENT)
152 mlog_errno(status);
153 parent = ERR_PTR(status);
154 goto unlock_nfs_sync;
155 }
156
157 status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
158 if (status < 0) {
159 parent = ERR_PTR(-ENOENT);
160 goto bail_unlock;
161 }
162
163 status = ocfs2_test_inode_bit(OCFS2_SB(dir->i_sb), blkno, &set);
164 if (status < 0) {
165 if (status == -EINVAL) {
166 status = -ESTALE;
167 } else
168 mlog(ML_ERROR, "test inode bit failed %d\n", status);
169 parent = ERR_PTR(status);
170 goto bail_unlock;
171 }
172
173 trace_ocfs2_get_dentry_test_bit(status, set);
174 if (!set) {
175 status = -ESTALE;
176 parent = ERR_PTR(status);
177 goto bail_unlock;
178 }
179
180 parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
181
182 bail_unlock:
183 ocfs2_inode_unlock(dir, 0);
184
185 unlock_nfs_sync:
186 ocfs2_nfs_sync_unlock(OCFS2_SB(dir->i_sb), 1);
187
188 bail:
189 trace_ocfs2_get_parent_end(parent);
190
191 return parent;
192 }
193
ocfs2_encode_fh(struct inode * inode,u32 * fh_in,int * max_len,struct inode * parent)194 static int ocfs2_encode_fh(struct inode *inode, u32 *fh_in, int *max_len,
195 struct inode *parent)
196 {
197 int len = *max_len;
198 int type = 1;
199 u64 blkno;
200 u32 generation;
201 __le32 *fh = (__force __le32 *) fh_in;
202
203 #ifdef TRACE_HOOKS_ARE_NOT_BRAINDEAD_IN_YOUR_OPINION
204 #error "You go ahead and fix that mess, then. Somehow"
205 trace_ocfs2_encode_fh_begin(dentry, dentry->d_name.len,
206 dentry->d_name.name,
207 fh, len, connectable);
208 #endif
209
210 if (parent && (len < 6)) {
211 *max_len = 6;
212 type = FILEID_INVALID;
213 goto bail;
214 } else if (len < 3) {
215 *max_len = 3;
216 type = FILEID_INVALID;
217 goto bail;
218 }
219
220 blkno = OCFS2_I(inode)->ip_blkno;
221 generation = inode->i_generation;
222
223 trace_ocfs2_encode_fh_self((unsigned long long)blkno, generation);
224
225 len = 3;
226 fh[0] = cpu_to_le32((u32)(blkno >> 32));
227 fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff));
228 fh[2] = cpu_to_le32(generation);
229
230 if (parent) {
231 blkno = OCFS2_I(parent)->ip_blkno;
232 generation = parent->i_generation;
233
234 fh[3] = cpu_to_le32((u32)(blkno >> 32));
235 fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff));
236 fh[5] = cpu_to_le32(generation);
237
238 len = 6;
239 type = 2;
240
241 trace_ocfs2_encode_fh_parent((unsigned long long)blkno,
242 generation);
243 }
244
245 *max_len = len;
246
247 bail:
248 trace_ocfs2_encode_fh_type(type);
249 return type;
250 }
251
ocfs2_fh_to_dentry(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)252 static struct dentry *ocfs2_fh_to_dentry(struct super_block *sb,
253 struct fid *fid, int fh_len, int fh_type)
254 {
255 struct ocfs2_inode_handle handle;
256
257 if (fh_len < 3 || fh_type > 2)
258 return NULL;
259
260 handle.ih_blkno = (u64)le32_to_cpu(fid->raw[0]) << 32;
261 handle.ih_blkno |= (u64)le32_to_cpu(fid->raw[1]);
262 handle.ih_generation = le32_to_cpu(fid->raw[2]);
263 return ocfs2_get_dentry(sb, &handle);
264 }
265
ocfs2_fh_to_parent(struct super_block * sb,struct fid * fid,int fh_len,int fh_type)266 static struct dentry *ocfs2_fh_to_parent(struct super_block *sb,
267 struct fid *fid, int fh_len, int fh_type)
268 {
269 struct ocfs2_inode_handle parent;
270
271 if (fh_type != 2 || fh_len < 6)
272 return NULL;
273
274 parent.ih_blkno = (u64)le32_to_cpu(fid->raw[3]) << 32;
275 parent.ih_blkno |= (u64)le32_to_cpu(fid->raw[4]);
276 parent.ih_generation = le32_to_cpu(fid->raw[5]);
277 return ocfs2_get_dentry(sb, &parent);
278 }
279
280 const struct export_operations ocfs2_export_ops = {
281 .encode_fh = ocfs2_encode_fh,
282 .fh_to_dentry = ocfs2_fh_to_dentry,
283 .fh_to_parent = ocfs2_fh_to_parent,
284 .get_parent = ocfs2_get_parent,
285 };
286