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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2004-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include "xfs.h"
19#include "xfs_types.h"
David Chinnerda353b02007-08-28 14:00:13 +100020#include "xfs_inum.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include "xfs_log.h"
22#include "xfs_trans.h"
23#include "xfs_sb.h"
David Chinnerda353b02007-08-28 14:00:13 +100024#include "xfs_ag.h"
Barry Naujok556b8b12008-04-10 12:22:07 +100025#include "xfs_dir2.h"
David Chinnerda353b02007-08-28 14:00:13 +100026#include "xfs_dmapi.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include "xfs_mount.h"
28#include "xfs_export.h"
Christoph Hellwig739bfb22007-08-29 10:58:01 +100029#include "xfs_vnodeops.h"
30#include "xfs_bmap_btree.h"
31#include "xfs_inode.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33/*
Christoph Hellwigc38344f2007-10-21 16:42:11 -070034 * Note that we only accept fileids which are long enough rather than allow
35 * the parent generation number to default to zero. XFS considers zero a
36 * valid generation number not an invalid/wildcard value.
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 */
Christoph Hellwigc38344f2007-10-21 16:42:11 -070038static int xfs_fileid_length(int fileid_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039{
Christoph Hellwigc38344f2007-10-21 16:42:11 -070040 switch (fileid_type) {
41 case FILEID_INO32_GEN:
42 return 2;
43 case FILEID_INO32_GEN_PARENT:
44 return 4;
45 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
46 return 3;
47 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
48 return 6;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 }
Christoph Hellwigc38344f2007-10-21 16:42:11 -070050 return 255; /* invalid */
Linus Torvalds1da177e2005-04-16 15:20:36 -070051}
52
Linus Torvalds1da177e2005-04-16 15:20:36 -070053STATIC int
Nathan Scotta50cd262006-03-14 14:06:18 +110054xfs_fs_encode_fh(
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 struct dentry *dentry,
56 __u32 *fh,
57 int *max_len,
58 int connectable)
59{
Christoph Hellwigc38344f2007-10-21 16:42:11 -070060 struct fid *fid = (struct fid *)fh;
61 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 struct inode *inode = dentry->d_inode;
Christoph Hellwigc38344f2007-10-21 16:42:11 -070063 int fileid_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66 /* Directories don't need their parent encoded, they have ".." */
Christoph Hellwig24bd8612008-03-06 13:45:16 +110067 if (S_ISDIR(inode->i_mode) || !connectable)
Christoph Hellwigc38344f2007-10-21 16:42:11 -070068 fileid_type = FILEID_INO32_GEN;
69 else
70 fileid_type = FILEID_INO32_GEN_PARENT;
71
72 /* filesystem may contain 64bit inode numbers */
73 if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS))
74 fileid_type |= XFS_FILEID_TYPE_64FLAG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76 /*
77 * Only encode if there is enough space given. In practice
78 * this means we can't export a filesystem with 64bit inodes
79 * over NFSv2 with the subtree_check export option; the other
80 * seven combinations work. The real answer is "don't use v2".
81 */
Christoph Hellwigc38344f2007-10-21 16:42:11 -070082 len = xfs_fileid_length(fileid_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 if (*max_len < len)
84 return 255;
85 *max_len = len;
86
Christoph Hellwigc38344f2007-10-21 16:42:11 -070087 switch (fileid_type) {
88 case FILEID_INO32_GEN_PARENT:
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 spin_lock(&dentry->d_lock);
Christoph Hellwigc38344f2007-10-21 16:42:11 -070090 fid->i32.parent_ino = dentry->d_parent->d_inode->i_ino;
91 fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 spin_unlock(&dentry->d_lock);
Christoph Hellwigc38344f2007-10-21 16:42:11 -070093 /*FALLTHRU*/
94 case FILEID_INO32_GEN:
95 fid->i32.ino = inode->i_ino;
96 fid->i32.gen = inode->i_generation;
97 break;
98 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
99 spin_lock(&dentry->d_lock);
100 fid64->parent_ino = dentry->d_parent->d_inode->i_ino;
101 fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
102 spin_unlock(&dentry->d_lock);
103 /*FALLTHRU*/
104 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
105 fid64->ino = inode->i_ino;
106 fid64->gen = inode->i_generation;
107 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 }
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700109
110 return fileid_type;
111}
112
113STATIC struct inode *
114xfs_nfs_get_inode(
115 struct super_block *sb,
116 u64 ino,
117 u32 generation)
118 {
Christoph Hellwigf71354b2007-12-18 16:26:55 +1100119 xfs_mount_t *mp = XFS_M(sb);
120 xfs_inode_t *ip;
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700121 int error;
122
Christoph Hellwigf71354b2007-12-18 16:26:55 +1100123 /*
124 * NFS can sometimes send requests for ino 0. Fail them gracefully.
125 */
126 if (ino == 0)
127 return ERR_PTR(-ESTALE);
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700128
Christoph Hellwigf71354b2007-12-18 16:26:55 +1100129 error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_SHARED, &ip, 0);
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700130 if (error)
131 return ERR_PTR(-error);
Christoph Hellwigf71354b2007-12-18 16:26:55 +1100132 if (!ip)
133 return ERR_PTR(-EIO);
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700134
Christoph Hellwig6a7f4222008-04-22 17:33:40 +1000135 if (ip->i_d.di_gen != generation) {
Christoph Hellwigf71354b2007-12-18 16:26:55 +1100136 xfs_iput_new(ip, XFS_ILOCK_SHARED);
137 return ERR_PTR(-ENOENT);
138 }
139
140 xfs_iunlock(ip, XFS_ILOCK_SHARED);
David Chinner01651642008-08-13 15:45:15 +1000141 return VFS_I(ip);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142}
143
144STATIC struct dentry *
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700145xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
146 int fh_len, int fileid_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147{
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700148 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
149 struct inode *inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700151 if (fh_len < xfs_fileid_length(fileid_type))
152 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700154 switch (fileid_type) {
155 case FILEID_INO32_GEN_PARENT:
156 case FILEID_INO32_GEN:
157 inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
158 break;
159 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
160 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
161 inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
162 break;
163 }
164
Christoph Hellwig44003722008-08-11 15:49:04 +0200165 return d_obtain_alias(inode);
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700166}
167
168STATIC struct dentry *
169xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
170 int fh_len, int fileid_type)
171{
172 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
173 struct inode *inode = NULL;
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700174
175 switch (fileid_type) {
176 case FILEID_INO32_GEN_PARENT:
177 inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
178 fid->i32.parent_gen);
179 break;
180 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
181 inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
182 fid64->parent_gen);
183 break;
184 }
185
Christoph Hellwig44003722008-08-11 15:49:04 +0200186 return d_obtain_alias(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187}
188
189STATIC struct dentry *
Nathan Scotta50cd262006-03-14 14:06:18 +1100190xfs_fs_get_parent(
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 struct dentry *child)
192{
193 int error;
Christoph Hellwigef1f5e72008-03-06 13:46:25 +1100194 struct xfs_inode *cip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
Barry Naujok384f3ce2008-05-21 16:58:22 +1000196 error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 if (unlikely(error))
198 return ERR_PTR(-error);
199
Christoph Hellwig44003722008-08-11 15:49:04 +0200200 return d_obtain_alias(VFS_I(cip));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201}
202
Christoph Hellwig39655162007-10-21 16:42:17 -0700203const struct export_operations xfs_export_operations = {
Nathan Scotta50cd262006-03-14 14:06:18 +1100204 .encode_fh = xfs_fs_encode_fh,
Christoph Hellwigc38344f2007-10-21 16:42:11 -0700205 .fh_to_dentry = xfs_fs_fh_to_dentry,
206 .fh_to_parent = xfs_fs_fh_to_parent,
Nathan Scotta50cd262006-03-14 14:06:18 +1100207 .get_parent = xfs_fs_get_parent,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208};