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1/*
2 * Copyright (c) 2004-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
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.
8 *
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.
13 *
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
17 */
18#include "xfs.h"
19#include "xfs_types.h"
20#include "xfs_inum.h"
21#include "xfs_log.h"
22#include "xfs_trans.h"
23#include "xfs_sb.h"
24#include "xfs_ag.h"
25#include "xfs_dir2.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_inode_item.h"
32#include "xfs_trace.h"
33
34/*
35 * Note that we only accept fileids which are long enough rather than allow
36 * the parent generation number to default to zero. XFS considers zero a
37 * valid generation number not an invalid/wildcard value.
38 */
39static int xfs_fileid_length(int fileid_type)
40{
41 switch (fileid_type) {
42 case FILEID_INO32_GEN:
43 return 2;
44 case FILEID_INO32_GEN_PARENT:
45 return 4;
46 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
47 return 3;
48 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
49 return 6;
50 }
51 return 255; /* invalid */
52}
53
54STATIC int
55xfs_fs_encode_fh(
56 struct dentry *dentry,
57 __u32 *fh,
58 int *max_len,
59 int connectable)
60{
61 struct fid *fid = (struct fid *)fh;
62 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh;
63 struct inode *inode = dentry->d_inode;
64 int fileid_type;
65 int len;
66
67 /* Directories don't need their parent encoded, they have ".." */
68 if (S_ISDIR(inode->i_mode) || !connectable)
69 fileid_type = FILEID_INO32_GEN;
70 else
71 fileid_type = FILEID_INO32_GEN_PARENT;
72
73 /*
74 * If the the filesystem may contain 64bit inode numbers, we need
75 * to use larger file handles that can represent them.
76 *
77 * While we only allocate inodes that do not fit into 32 bits any
78 * large enough filesystem may contain them, thus the slightly
79 * confusing looking conditional below.
80 */
81 if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) ||
82 (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
83 fileid_type |= XFS_FILEID_TYPE_64FLAG;
84
85 /*
86 * Only encode if there is enough space given. In practice
87 * this means we can't export a filesystem with 64bit inodes
88 * over NFSv2 with the subtree_check export option; the other
89 * seven combinations work. The real answer is "don't use v2".
90 */
91 len = xfs_fileid_length(fileid_type);
92 if (*max_len < len) {
93 *max_len = len;
94 return 255;
95 }
96 *max_len = len;
97
98 switch (fileid_type) {
99 case FILEID_INO32_GEN_PARENT:
100 spin_lock(&dentry->d_lock);
101 fid->i32.parent_ino = dentry->d_parent->d_inode->i_ino;
102 fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
103 spin_unlock(&dentry->d_lock);
104 /*FALLTHRU*/
105 case FILEID_INO32_GEN:
106 fid->i32.ino = inode->i_ino;
107 fid->i32.gen = inode->i_generation;
108 break;
109 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
110 spin_lock(&dentry->d_lock);
111 fid64->parent_ino = dentry->d_parent->d_inode->i_ino;
112 fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
113 spin_unlock(&dentry->d_lock);
114 /*FALLTHRU*/
115 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
116 fid64->ino = inode->i_ino;
117 fid64->gen = inode->i_generation;
118 break;
119 }
120
121 return fileid_type;
122}
123
124STATIC struct inode *
125xfs_nfs_get_inode(
126 struct super_block *sb,
127 u64 ino,
128 u32 generation)
129 {
130 xfs_mount_t *mp = XFS_M(sb);
131 xfs_inode_t *ip;
132 int error;
133
134 /*
135 * NFS can sometimes send requests for ino 0. Fail them gracefully.
136 */
137 if (ino == 0)
138 return ERR_PTR(-ESTALE);
139
140 /*
141 * The XFS_IGET_UNTRUSTED means that an invalid inode number is just
142 * fine and not an indication of a corrupted filesystem as clients can
143 * send invalid file handles and we have to handle it gracefully..
144 */
145 error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
146 if (error) {
147 /*
148 * EINVAL means the inode cluster doesn't exist anymore.
149 * This implies the filehandle is stale, so we should
150 * translate it here.
151 * We don't use ESTALE directly down the chain to not
152 * confuse applications using bulkstat that expect EINVAL.
153 */
154 if (error == EINVAL || error == ENOENT)
155 error = ESTALE;
156 return ERR_PTR(-error);
157 }
158
159 if (ip->i_d.di_gen != generation) {
160 IRELE(ip);
161 return ERR_PTR(-ESTALE);
162 }
163
164 return VFS_I(ip);
165}
166
167STATIC struct dentry *
168xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
169 int fh_len, int fileid_type)
170{
171 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
172 struct inode *inode = NULL;
173
174 if (fh_len < xfs_fileid_length(fileid_type))
175 return NULL;
176
177 switch (fileid_type) {
178 case FILEID_INO32_GEN_PARENT:
179 case FILEID_INO32_GEN:
180 inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
181 break;
182 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
183 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
184 inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
185 break;
186 }
187
188 return d_obtain_alias(inode);
189}
190
191STATIC struct dentry *
192xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
193 int fh_len, int fileid_type)
194{
195 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
196 struct inode *inode = NULL;
197
198 switch (fileid_type) {
199 case FILEID_INO32_GEN_PARENT:
200 inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
201 fid->i32.parent_gen);
202 break;
203 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
204 inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
205 fid64->parent_gen);
206 break;
207 }
208
209 return d_obtain_alias(inode);
210}
211
212STATIC struct dentry *
213xfs_fs_get_parent(
214 struct dentry *child)
215{
216 int error;
217 struct xfs_inode *cip;
218
219 error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
220 if (unlikely(error))
221 return ERR_PTR(-error);
222
223 return d_obtain_alias(VFS_I(cip));
224}
225
226STATIC int
227xfs_fs_nfs_commit_metadata(
228 struct inode *inode)
229{
230 struct xfs_inode *ip = XFS_I(inode);
231 struct xfs_mount *mp = ip->i_mount;
232 int error = 0;
233
234 xfs_ilock(ip, XFS_ILOCK_SHARED);
235 if (xfs_ipincount(ip)) {
236 error = _xfs_log_force_lsn(mp, ip->i_itemp->ili_last_lsn,
237 XFS_LOG_SYNC, NULL);
238 }
239 xfs_iunlock(ip, XFS_ILOCK_SHARED);
240
241 return error;
242}
243
244const struct export_operations xfs_export_operations = {
245 .encode_fh = xfs_fs_encode_fh,
246 .fh_to_dentry = xfs_fs_fh_to_dentry,
247 .fh_to_parent = xfs_fs_fh_to_parent,
248 .get_parent = xfs_fs_get_parent,
249 .commit_metadata = xfs_fs_nfs_commit_metadata,
250};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2004-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_shared.h"
8#include "xfs_format.h"
9#include "xfs_log_format.h"
10#include "xfs_trans_resv.h"
11#include "xfs_mount.h"
12#include "xfs_dir2.h"
13#include "xfs_export.h"
14#include "xfs_inode.h"
15#include "xfs_trans.h"
16#include "xfs_inode_item.h"
17#include "xfs_icache.h"
18#include "xfs_log.h"
19#include "xfs_pnfs.h"
20
21/*
22 * Note that we only accept fileids which are long enough rather than allow
23 * the parent generation number to default to zero. XFS considers zero a
24 * valid generation number not an invalid/wildcard value.
25 */
26static int xfs_fileid_length(int fileid_type)
27{
28 switch (fileid_type) {
29 case FILEID_INO32_GEN:
30 return 2;
31 case FILEID_INO32_GEN_PARENT:
32 return 4;
33 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
34 return 3;
35 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
36 return 6;
37 }
38 return FILEID_INVALID;
39}
40
41STATIC int
42xfs_fs_encode_fh(
43 struct inode *inode,
44 __u32 *fh,
45 int *max_len,
46 struct inode *parent)
47{
48 struct fid *fid = (struct fid *)fh;
49 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh;
50 int fileid_type;
51 int len;
52
53 /* Directories don't need their parent encoded, they have ".." */
54 if (!parent)
55 fileid_type = FILEID_INO32_GEN;
56 else
57 fileid_type = FILEID_INO32_GEN_PARENT;
58
59 /*
60 * If the the filesystem may contain 64bit inode numbers, we need
61 * to use larger file handles that can represent them.
62 *
63 * While we only allocate inodes that do not fit into 32 bits any
64 * large enough filesystem may contain them, thus the slightly
65 * confusing looking conditional below.
66 */
67 if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) ||
68 (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
69 fileid_type |= XFS_FILEID_TYPE_64FLAG;
70
71 /*
72 * Only encode if there is enough space given. In practice
73 * this means we can't export a filesystem with 64bit inodes
74 * over NFSv2 with the subtree_check export option; the other
75 * seven combinations work. The real answer is "don't use v2".
76 */
77 len = xfs_fileid_length(fileid_type);
78 if (*max_len < len) {
79 *max_len = len;
80 return FILEID_INVALID;
81 }
82 *max_len = len;
83
84 switch (fileid_type) {
85 case FILEID_INO32_GEN_PARENT:
86 fid->i32.parent_ino = XFS_I(parent)->i_ino;
87 fid->i32.parent_gen = parent->i_generation;
88 /*FALLTHRU*/
89 case FILEID_INO32_GEN:
90 fid->i32.ino = XFS_I(inode)->i_ino;
91 fid->i32.gen = inode->i_generation;
92 break;
93 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
94 fid64->parent_ino = XFS_I(parent)->i_ino;
95 fid64->parent_gen = parent->i_generation;
96 /*FALLTHRU*/
97 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
98 fid64->ino = XFS_I(inode)->i_ino;
99 fid64->gen = inode->i_generation;
100 break;
101 }
102
103 return fileid_type;
104}
105
106STATIC struct inode *
107xfs_nfs_get_inode(
108 struct super_block *sb,
109 u64 ino,
110 u32 generation)
111{
112 xfs_mount_t *mp = XFS_M(sb);
113 xfs_inode_t *ip;
114 int error;
115
116 /*
117 * NFS can sometimes send requests for ino 0. Fail them gracefully.
118 */
119 if (ino == 0)
120 return ERR_PTR(-ESTALE);
121
122 /*
123 * The XFS_IGET_UNTRUSTED means that an invalid inode number is just
124 * fine and not an indication of a corrupted filesystem as clients can
125 * send invalid file handles and we have to handle it gracefully..
126 */
127 error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
128 if (error) {
129
130 /*
131 * EINVAL means the inode cluster doesn't exist anymore.
132 * EFSCORRUPTED means the metadata pointing to the inode cluster
133 * or the inode cluster itself is corrupt. This implies the
134 * filehandle is stale, so we should translate it here.
135 * We don't use ESTALE directly down the chain to not
136 * confuse applications using bulkstat that expect EINVAL.
137 */
138 switch (error) {
139 case -EINVAL:
140 case -ENOENT:
141 case -EFSCORRUPTED:
142 error = -ESTALE;
143 break;
144 default:
145 break;
146 }
147 return ERR_PTR(error);
148 }
149
150 if (VFS_I(ip)->i_generation != generation) {
151 xfs_irele(ip);
152 return ERR_PTR(-ESTALE);
153 }
154
155 return VFS_I(ip);
156}
157
158STATIC struct dentry *
159xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
160 int fh_len, int fileid_type)
161{
162 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
163 struct inode *inode = NULL;
164
165 if (fh_len < xfs_fileid_length(fileid_type))
166 return NULL;
167
168 switch (fileid_type) {
169 case FILEID_INO32_GEN_PARENT:
170 case FILEID_INO32_GEN:
171 inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
172 break;
173 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
174 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
175 inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
176 break;
177 }
178
179 return d_obtain_alias(inode);
180}
181
182STATIC struct dentry *
183xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
184 int fh_len, int fileid_type)
185{
186 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
187 struct inode *inode = NULL;
188
189 if (fh_len < xfs_fileid_length(fileid_type))
190 return NULL;
191
192 switch (fileid_type) {
193 case FILEID_INO32_GEN_PARENT:
194 inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
195 fid->i32.parent_gen);
196 break;
197 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
198 inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
199 fid64->parent_gen);
200 break;
201 }
202
203 return d_obtain_alias(inode);
204}
205
206STATIC struct dentry *
207xfs_fs_get_parent(
208 struct dentry *child)
209{
210 int error;
211 struct xfs_inode *cip;
212
213 error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL);
214 if (unlikely(error))
215 return ERR_PTR(error);
216
217 return d_obtain_alias(VFS_I(cip));
218}
219
220STATIC int
221xfs_fs_nfs_commit_metadata(
222 struct inode *inode)
223{
224 struct xfs_inode *ip = XFS_I(inode);
225 struct xfs_mount *mp = ip->i_mount;
226 xfs_lsn_t lsn = 0;
227
228 xfs_ilock(ip, XFS_ILOCK_SHARED);
229 if (xfs_ipincount(ip))
230 lsn = ip->i_itemp->ili_last_lsn;
231 xfs_iunlock(ip, XFS_ILOCK_SHARED);
232
233 if (!lsn)
234 return 0;
235 return xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
236}
237
238const struct export_operations xfs_export_operations = {
239 .encode_fh = xfs_fs_encode_fh,
240 .fh_to_dentry = xfs_fs_fh_to_dentry,
241 .fh_to_parent = xfs_fs_fh_to_parent,
242 .get_parent = xfs_fs_get_parent,
243 .commit_metadata = xfs_fs_nfs_commit_metadata,
244#ifdef CONFIG_EXPORTFS_BLOCK_OPS
245 .get_uuid = xfs_fs_get_uuid,
246 .map_blocks = xfs_fs_map_blocks,
247 .commit_blocks = xfs_fs_commit_blocks,
248#endif
249};