2 * Copyright (c) 2004-2005 Silicon Graphics, Inc.
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
7 * published by the Free Software Foundation.
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.
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
19 #include "xfs_types.h"
22 #include "xfs_trans.h"
25 #include "xfs_dmapi.h"
26 #include "xfs_mount.h"
27 #include "xfs_export.h"
28 #include "xfs_vnodeops.h"
29 #include "xfs_bmap_btree.h"
30 #include "xfs_inode.h"
31 #include "xfs_vfsops.h"
33 static struct dentry dotdot = { .d_name.name = "..", .d_name.len = 2, };
36 * XFS encodes and decodes the fileid portion of NFS filehandles
37 * itself instead of letting the generic NFS code do it. This
38 * allows filesystems with 64 bit inode numbers to be exported.
40 * Note that a side effect is that xfs_vget() won't be passed a
41 * zero inode/generation pair under normal circumstances. As
42 * however a malicious client could send us such data, the check
43 * remains in that code.
46 STATIC struct dentry *
48 struct super_block *sb,
64 is64 = (fileid_type & XFS_FILEID_TYPE_64FLAG);
65 fileid_type &= ~XFS_FILEID_TYPE_64FLAG;
69 * Note that we only accept fileids which are long enough
70 * rather than allow the parent generation number to default
71 * to zero. XFS considers zero a valid generation number not
72 * an invalid/wildcard value. There's little point printk'ing
73 * a warning here as we don't have the client information
74 * which would make such a warning useful.
76 if (fileid_type > 2 ||
77 fh_len < xfs_fileid_length((fileid_type == 2), is64))
80 p = xfs_fileid_decode_fid2(p, &ifid, is64);
82 if (fileid_type == 2) {
83 p = xfs_fileid_decode_fid2(p, &pfid, is64);
88 return sb->s_export_op->find_exported_dentry(sb, fh, parent, acceptable, context);
94 struct dentry *dentry,
99 struct inode *inode = dentry->d_inode;
105 bhv_vfs_t *vfs = vfs_from_sb(inode->i_sb);
107 if (!(vfs->vfs_flag & VFS_32BITINODES)) {
108 /* filesystem may contain 64bit inode numbers */
109 is64 = XFS_FILEID_TYPE_64FLAG;
113 /* Directories don't need their parent encoded, they have ".." */
114 if (S_ISDIR(inode->i_mode))
118 * Only encode if there is enough space given. In practice
119 * this means we can't export a filesystem with 64bit inodes
120 * over NFSv2 with the subtree_check export option; the other
121 * seven combinations work. The real answer is "don't use v2".
123 len = xfs_fileid_length(connectable, is64);
128 p = xfs_fileid_encode_inode(p, inode, is64);
130 spin_lock(&dentry->d_lock);
131 p = xfs_fileid_encode_inode(p, dentry->d_parent->d_inode, is64);
132 spin_unlock(&dentry->d_lock);
135 BUG_ON((p - fh) != len);
139 STATIC struct dentry *
141 struct super_block *sb,
146 struct dentry *result;
149 error = xfs_vget(XFS_M(sb), &vp, (fid_t *)data);
150 if (error || vp == NULL)
151 return ERR_PTR(-ESTALE) ;
153 inode = vn_to_inode(vp);
154 result = d_alloc_anon(inode);
157 return ERR_PTR(-ENOMEM);
162 STATIC struct dentry *
164 struct dentry *child)
168 struct dentry *parent;
171 error = xfs_lookup(XFS_I(child->d_inode), &dotdot, &cvp);
173 return ERR_PTR(-error);
175 parent = d_alloc_anon(vn_to_inode(cvp));
176 if (unlikely(!parent)) {
178 return ERR_PTR(-ENOMEM);
183 struct export_operations xfs_export_operations = {
184 .decode_fh = xfs_fs_decode_fh,
185 .encode_fh = xfs_fs_encode_fh,
186 .get_parent = xfs_fs_get_parent,
187 .get_dentry = xfs_fs_get_dentry,