1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/*
* Copyright (c) 2004-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_export.h"
#include "xfs_vnodeops.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_vfsops.h"
/*
* Note that we only accept fileids which are long enough rather than allow
* the parent generation number to default to zero. XFS considers zero a
* valid generation number not an invalid/wildcard value.
*/
static int xfs_fileid_length(int fileid_type)
{
switch (fileid_type) {
case FILEID_INO32_GEN:
return 2;
case FILEID_INO32_GEN_PARENT:
return 4;
case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
return 3;
case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
return 6;
}
return 255; /* invalid */
}
STATIC int
xfs_fs_encode_fh(
struct dentry *dentry,
__u32 *fh,
int *max_len,
int connectable)
{
struct fid *fid = (struct fid *)fh;
struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh;
struct inode *inode = dentry->d_inode;
int fileid_type;
int len;
/* Directories don't need their parent encoded, they have ".." */
if (S_ISDIR(inode->i_mode) || !connectable)
fileid_type = FILEID_INO32_GEN;
else
fileid_type = FILEID_INO32_GEN_PARENT;
/* filesystem may contain 64bit inode numbers */
if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS))
fileid_type |= XFS_FILEID_TYPE_64FLAG;
/*
* Only encode if there is enough space given. In practice
* this means we can't export a filesystem with 64bit inodes
* over NFSv2 with the subtree_check export option; the other
* seven combinations work. The real answer is "don't use v2".
*/
len = xfs_fileid_length(fileid_type);
if (*max_len < len)
return 255;
*max_len = len;
switch (fileid_type) {
case FILEID_INO32_GEN_PARENT:
spin_lock(&dentry->d_lock);
fid->i32.parent_ino = dentry->d_parent->d_inode->i_ino;
fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
spin_unlock(&dentry->d_lock);
/*FALLTHRU*/
case FILEID_INO32_GEN:
fid->i32.ino = inode->i_ino;
fid->i32.gen = inode->i_generation;
break;
case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
spin_lock(&dentry->d_lock);
fid64->parent_ino = dentry->d_parent->d_inode->i_ino;
fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
spin_unlock(&dentry->d_lock);
/*FALLTHRU*/
case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
fid64->ino = inode->i_ino;
fid64->gen = inode->i_generation;
break;
}
return fileid_type;
}
STATIC struct inode *
xfs_nfs_get_inode(
struct super_block *sb,
u64 ino,
u32 generation)
{
xfs_mount_t *mp = XFS_M(sb);
xfs_inode_t *ip;
int error;
/*
* NFS can sometimes send requests for ino 0. Fail them gracefully.
*/
if (ino == 0)
return ERR_PTR(-ESTALE);
error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_SHARED, &ip, 0);
if (error)
return ERR_PTR(-error);
if (!ip)
return ERR_PTR(-EIO);
if (ip->i_d.di_gen != generation) {
xfs_iput_new(ip, XFS_ILOCK_SHARED);
return ERR_PTR(-ENOENT);
}
xfs_iunlock(ip, XFS_ILOCK_SHARED);
return VFS_I(ip);
}
STATIC struct dentry *
xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
int fh_len, int fileid_type)
{
struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
struct inode *inode = NULL;
if (fh_len < xfs_fileid_length(fileid_type))
return NULL;
switch (fileid_type) {
case FILEID_INO32_GEN_PARENT:
case FILEID_INO32_GEN:
inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
break;
case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
break;
}
return d_obtain_alias(inode);
}
STATIC struct dentry *
xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
int fh_len, int fileid_type)
{
struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
struct inode *inode = NULL;
switch (fileid_type) {
case FILEID_INO32_GEN_PARENT:
inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
fid->i32.parent_gen);
break;
case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
fid64->parent_gen);
break;
}
return d_obtain_alias(inode);
}
STATIC struct dentry *
xfs_fs_get_parent(
struct dentry *child)
{
int error;
struct xfs_inode *cip;
error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
if (unlikely(error))
return ERR_PTR(-error);
return d_obtain_alias(VFS_I(cip));
}
const struct export_operations xfs_export_operations = {
.encode_fh = xfs_fs_encode_fh,
.fh_to_dentry = xfs_fs_fh_to_dentry,
.fh_to_parent = xfs_fs_fh_to_parent,
.get_parent = xfs_fs_get_parent,
};
|
