Root/fs/ocfs2/export.c

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#define MLOG_MASK_PREFIX ML_EXPORT
30#include <cluster/masklog.h>
31
32#include "ocfs2.h"
33
34#include "alloc.h"
35#include "dir.h"
36#include "dlmglue.h"
37#include "dcache.h"
38#include "export.h"
39#include "inode.h"
40
41#include "buffer_head_io.h"
42#include "suballoc.h"
43
44struct ocfs2_inode_handle
45{
46    u64 ih_blkno;
47    u32 ih_generation;
48};
49
50static 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    mlog_entry("(0x%p, 0x%p)\n", sb, handle);
60
61    if (blkno == 0) {
62        mlog(0, "nfs wants inode with blkno: 0\n");
63        result = ERR_PTR(-ESTALE);
64        goto bail;
65    }
66
67    inode = ocfs2_ilookup(sb, blkno);
68    /*
69     * If the inode exists in memory, we only need to check it's
70     * generation number
71     */
72    if (inode)
73        goto check_gen;
74
75    /*
76     * This will synchronize us against ocfs2_delete_inode() on
77     * all nodes
78     */
79    status = ocfs2_nfs_sync_lock(osb, 1);
80    if (status < 0) {
81        mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status);
82        goto check_err;
83    }
84
85    status = ocfs2_test_inode_bit(osb, blkno, &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            mlog(0, "test inode bit failed %d\n", status);
94            status = -ESTALE;
95        } else {
96            mlog(ML_ERROR, "test inode bit failed %d\n", status);
97        }
98        goto unlock_nfs_sync;
99    }
100
101    /* If the inode allocator bit is clear, this inode must be stale */
102    if (!set) {
103        mlog(0, "inode %llu suballoc bit is clear\n",
104             (unsigned long long)blkno);
105        status = -ESTALE;
106        goto unlock_nfs_sync;
107    }
108
109    inode = ocfs2_iget(osb, blkno, 0, 0);
110
111unlock_nfs_sync:
112    ocfs2_nfs_sync_unlock(osb, 1);
113
114check_err:
115    if (status < 0) {
116        if (status == -ESTALE) {
117            mlog(0, "stale inode ino: %llu generation: %u\n",
118                 (unsigned long long)blkno, handle->ih_generation);
119        }
120        result = ERR_PTR(status);
121        goto bail;
122    }
123
124    if (IS_ERR(inode)) {
125        mlog_errno(PTR_ERR(inode));
126        result = (void *)inode;
127        goto bail;
128    }
129
130check_gen:
131    if (handle->ih_generation != inode->i_generation) {
132        iput(inode);
133        mlog(0, "stale inode ino: %llu generation: %u\n",
134             (unsigned long long)blkno, handle->ih_generation);
135        result = ERR_PTR(-ESTALE);
136        goto bail;
137    }
138
139    result = d_obtain_alias(inode);
140    if (!IS_ERR(result))
141        result->d_op = &ocfs2_dentry_ops;
142    else
143        mlog_errno(PTR_ERR(result));
144
145bail:
146    mlog_exit_ptr(result);
147    return result;
148}
149
150static struct dentry *ocfs2_get_parent(struct dentry *child)
151{
152    int status;
153    u64 blkno;
154    struct dentry *parent;
155    struct inode *dir = child->d_inode;
156
157    mlog_entry("(0x%p, '%.*s')\n", child,
158           child->d_name.len, child->d_name.name);
159
160    mlog(0, "find parent of directory %llu\n",
161         (unsigned long long)OCFS2_I(dir)->ip_blkno);
162
163    status = ocfs2_inode_lock(dir, NULL, 0);
164    if (status < 0) {
165        if (status != -ENOENT)
166            mlog_errno(status);
167        parent = ERR_PTR(status);
168        goto bail;
169    }
170
171    status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno);
172    if (status < 0) {
173        parent = ERR_PTR(-ENOENT);
174        goto bail_unlock;
175    }
176
177    parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0));
178    if (!IS_ERR(parent))
179        parent->d_op = &ocfs2_dentry_ops;
180
181bail_unlock:
182    ocfs2_inode_unlock(dir, 0);
183
184bail:
185    mlog_exit_ptr(parent);
186
187    return parent;
188}
189
190static int ocfs2_encode_fh(struct dentry *dentry, u32 *fh_in, int *max_len,
191               int connectable)
192{
193    struct inode *inode = dentry->d_inode;
194    int len = *max_len;
195    int type = 1;
196    u64 blkno;
197    u32 generation;
198    __le32 *fh = (__force __le32 *) fh_in;
199
200    mlog_entry("(0x%p, '%.*s', 0x%p, %d, %d)\n", dentry,
201           dentry->d_name.len, dentry->d_name.name,
202           fh, len, connectable);
203
204    if (len < 3 || (connectable && len < 6)) {
205        mlog(ML_ERROR, "fh buffer is too small for encoding\n");
206        type = 255;
207        goto bail;
208    }
209
210    blkno = OCFS2_I(inode)->ip_blkno;
211    generation = inode->i_generation;
212
213    mlog(0, "Encoding fh: blkno: %llu, generation: %u\n",
214         (unsigned long long)blkno, generation);
215
216    len = 3;
217    fh[0] = cpu_to_le32((u32)(blkno >> 32));
218    fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff));
219    fh[2] = cpu_to_le32(generation);
220
221    if (connectable && !S_ISDIR(inode->i_mode)) {
222        struct inode *parent;
223
224        spin_lock(&dentry->d_lock);
225
226        parent = dentry->d_parent->d_inode;
227        blkno = OCFS2_I(parent)->ip_blkno;
228        generation = parent->i_generation;
229
230        fh[3] = cpu_to_le32((u32)(blkno >> 32));
231        fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff));
232        fh[5] = cpu_to_le32(generation);
233
234        spin_unlock(&dentry->d_lock);
235
236        len = 6;
237        type = 2;
238
239        mlog(0, "Encoding parent: blkno: %llu, generation: %u\n",
240             (unsigned long long)blkno, generation);
241    }
242
243    *max_len = len;
244
245bail:
246    mlog_exit(type);
247    return type;
248}
249
250static 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(fid->raw[0]) << 32;
259    handle.ih_blkno |= (u64)le32_to_cpu(fid->raw[1]);
260    handle.ih_generation = le32_to_cpu(fid->raw[2]);
261    return ocfs2_get_dentry(sb, &handle);
262}
263
264static 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(fid->raw[3]) << 32;
273    parent.ih_blkno |= (u64)le32_to_cpu(fid->raw[4]);
274    parent.ih_generation = le32_to_cpu(fid->raw[5]);
275    return ocfs2_get_dentry(sb, &parent);
276}
277
278const 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};
284

Archive Download this file



interactive