Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2004-2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
1da177e4 LT |
18 | #include "xfs.h" |
19 | #include "xfs_types.h" | |
20 | #include "xfs_dmapi.h" | |
21 | #include "xfs_log.h" | |
22 | #include "xfs_trans.h" | |
23 | #include "xfs_sb.h" | |
24 | #include "xfs_dir.h" | |
25 | #include "xfs_mount.h" | |
26 | #include "xfs_export.h" | |
27 | ||
28 | /* | |
7b718769 | 29 | * XFS encodes and decodes the fileid portion of NFS filehandles |
1da177e4 LT |
30 | * itself instead of letting the generic NFS code do it. This |
31 | * allows filesystems with 64 bit inode numbers to be exported. | |
32 | * | |
33 | * Note that a side effect is that xfs_vget() won't be passed a | |
34 | * zero inode/generation pair under normal circumstances. As | |
35 | * however a malicious client could send us such data, the check | |
36 | * remains in that code. | |
37 | */ | |
38 | ||
1da177e4 LT |
39 | STATIC struct dentry * |
40 | linvfs_decode_fh( | |
41 | struct super_block *sb, | |
42 | __u32 *fh, | |
43 | int fh_len, | |
44 | int fileid_type, | |
45 | int (*acceptable)( | |
46 | void *context, | |
47 | struct dentry *de), | |
48 | void *context) | |
49 | { | |
50 | xfs_fid2_t ifid; | |
51 | xfs_fid2_t pfid; | |
52 | void *parent = NULL; | |
53 | int is64 = 0; | |
54 | __u32 *p = fh; | |
55 | ||
56 | #if XFS_BIG_INUMS | |
57 | is64 = (fileid_type & XFS_FILEID_TYPE_64FLAG); | |
58 | fileid_type &= ~XFS_FILEID_TYPE_64FLAG; | |
59 | #endif | |
60 | ||
61 | /* | |
62 | * Note that we only accept fileids which are long enough | |
63 | * rather than allow the parent generation number to default | |
64 | * to zero. XFS considers zero a valid generation number not | |
65 | * an invalid/wildcard value. There's little point printk'ing | |
66 | * a warning here as we don't have the client information | |
67 | * which would make such a warning useful. | |
68 | */ | |
69 | if (fileid_type > 2 || | |
70 | fh_len < xfs_fileid_length((fileid_type == 2), is64)) | |
71 | return NULL; | |
72 | ||
73 | p = xfs_fileid_decode_fid2(p, &ifid, is64); | |
74 | ||
75 | if (fileid_type == 2) { | |
76 | p = xfs_fileid_decode_fid2(p, &pfid, is64); | |
77 | parent = &pfid; | |
78 | } | |
7b718769 | 79 | |
1da177e4 LT |
80 | fh = (__u32 *)&ifid; |
81 | return find_exported_dentry(sb, fh, parent, acceptable, context); | |
82 | } | |
83 | ||
84 | ||
85 | STATIC int | |
86 | linvfs_encode_fh( | |
87 | struct dentry *dentry, | |
88 | __u32 *fh, | |
89 | int *max_len, | |
90 | int connectable) | |
91 | { | |
92 | struct inode *inode = dentry->d_inode; | |
93 | int type = 1; | |
94 | __u32 *p = fh; | |
95 | int len; | |
96 | int is64 = 0; | |
97 | #if XFS_BIG_INUMS | |
98 | vfs_t *vfs = LINVFS_GET_VFS(inode->i_sb); | |
99 | xfs_mount_t *mp = XFS_VFSTOM(vfs); | |
7b718769 | 100 | |
1da177e4 LT |
101 | if (!(mp->m_flags & XFS_MOUNT_32BITINOOPT)) { |
102 | /* filesystem may contain 64bit inode numbers */ | |
103 | is64 = XFS_FILEID_TYPE_64FLAG; | |
104 | } | |
105 | #endif | |
106 | ||
107 | /* Directories don't need their parent encoded, they have ".." */ | |
108 | if (S_ISDIR(inode->i_mode)) | |
109 | connectable = 0; | |
110 | ||
111 | /* | |
112 | * Only encode if there is enough space given. In practice | |
113 | * this means we can't export a filesystem with 64bit inodes | |
114 | * over NFSv2 with the subtree_check export option; the other | |
115 | * seven combinations work. The real answer is "don't use v2". | |
116 | */ | |
117 | len = xfs_fileid_length(connectable, is64); | |
118 | if (*max_len < len) | |
119 | return 255; | |
120 | *max_len = len; | |
121 | ||
122 | p = xfs_fileid_encode_inode(p, inode, is64); | |
123 | if (connectable) { | |
124 | spin_lock(&dentry->d_lock); | |
125 | p = xfs_fileid_encode_inode(p, dentry->d_parent->d_inode, is64); | |
126 | spin_unlock(&dentry->d_lock); | |
127 | type = 2; | |
128 | } | |
129 | BUG_ON((p - fh) != len); | |
130 | return type | is64; | |
131 | } | |
132 | ||
133 | STATIC struct dentry * | |
134 | linvfs_get_dentry( | |
135 | struct super_block *sb, | |
136 | void *data) | |
137 | { | |
138 | vnode_t *vp; | |
139 | struct inode *inode; | |
140 | struct dentry *result; | |
141 | vfs_t *vfsp = LINVFS_GET_VFS(sb); | |
142 | int error; | |
143 | ||
144 | VFS_VGET(vfsp, &vp, (fid_t *)data, error); | |
145 | if (error || vp == NULL) | |
146 | return ERR_PTR(-ESTALE) ; | |
147 | ||
148 | inode = LINVFS_GET_IP(vp); | |
149 | result = d_alloc_anon(inode); | |
150 | if (!result) { | |
151 | iput(inode); | |
152 | return ERR_PTR(-ENOMEM); | |
153 | } | |
154 | return result; | |
155 | } | |
156 | ||
157 | STATIC struct dentry * | |
158 | linvfs_get_parent( | |
159 | struct dentry *child) | |
160 | { | |
161 | int error; | |
162 | vnode_t *vp, *cvp; | |
163 | struct dentry *parent; | |
164 | struct dentry dotdot; | |
165 | ||
166 | dotdot.d_name.name = ".."; | |
167 | dotdot.d_name.len = 2; | |
168 | dotdot.d_inode = NULL; | |
169 | ||
170 | cvp = NULL; | |
171 | vp = LINVFS_GET_VP(child->d_inode); | |
172 | VOP_LOOKUP(vp, &dotdot, &cvp, 0, NULL, NULL, error); | |
173 | if (unlikely(error)) | |
174 | return ERR_PTR(-error); | |
175 | ||
176 | parent = d_alloc_anon(LINVFS_GET_IP(cvp)); | |
177 | if (unlikely(!parent)) { | |
178 | VN_RELE(cvp); | |
179 | return ERR_PTR(-ENOMEM); | |
180 | } | |
181 | return parent; | |
182 | } | |
183 | ||
184 | struct export_operations linvfs_export_ops = { | |
185 | .decode_fh = linvfs_decode_fh, | |
186 | .encode_fh = linvfs_encode_fh, | |
187 | .get_parent = linvfs_get_parent, | |
188 | .get_dentry = linvfs_get_dentry, | |
189 | }; |