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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_log.h"
21#include "xfs_trans.h"
22#include "xfs_sb.h"
23#include "xfs_ag.h"
24#include "xfs_dir2.h"
25#include "xfs_mount.h"
26#include "xfs_export.h"
27#include "xfs_vnodeops.h"
28#include "xfs_bmap_btree.h"
29#include "xfs_inode.h"
30#include "xfs_inode_item.h"
31#include "xfs_trace.h"
32
33/*
34 * 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.
37 */
38static int xfs_fileid_length(int fileid_type)
39{
40 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;
49 }
50 return 255; /* invalid */
51}
52
53STATIC int
54xfs_fs_encode_fh(
55 struct inode *inode,
56 __u32 *fh,
57 int *max_len,
58 struct inode *parent)
59{
60 struct fid *fid = (struct fid *)fh;
61 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh;
62 int fileid_type;
63 int len;
64
65 /* Directories don't need their parent encoded, they have ".." */
66 if (!parent)
67 fileid_type = FILEID_INO32_GEN;
68 else
69 fileid_type = FILEID_INO32_GEN_PARENT;
70
71 /*
72 * If the the filesystem may contain 64bit inode numbers, we need
73 * to use larger file handles that can represent them.
74 *
75 * While we only allocate inodes that do not fit into 32 bits any
76 * large enough filesystem may contain them, thus the slightly
77 * confusing looking conditional below.
78 */
79 if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) ||
80 (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
81 fileid_type |= XFS_FILEID_TYPE_64FLAG;
82
83 /*
84 * Only encode if there is enough space given. In practice
85 * this means we can't export a filesystem with 64bit inodes
86 * over NFSv2 with the subtree_check export option; the other
87 * seven combinations work. The real answer is "don't use v2".
88 */
89 len = xfs_fileid_length(fileid_type);
90 if (*max_len < len) {
91 *max_len = len;
92 return 255;
93 }
94 *max_len = len;
95
96 switch (fileid_type) {
97 case FILEID_INO32_GEN_PARENT:
98 fid->i32.parent_ino = XFS_I(parent)->i_ino;
99 fid->i32.parent_gen = parent->i_generation;
100 /*FALLTHRU*/
101 case FILEID_INO32_GEN:
102 fid->i32.ino = XFS_I(inode)->i_ino;
103 fid->i32.gen = inode->i_generation;
104 break;
105 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
106 fid64->parent_ino = XFS_I(parent)->i_ino;
107 fid64->parent_gen = parent->i_generation;
108 /*FALLTHRU*/
109 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
110 fid64->ino = XFS_I(inode)->i_ino;
111 fid64->gen = inode->i_generation;
112 break;
113 }
114
115 return fileid_type;
116}
117
118STATIC struct inode *
119xfs_nfs_get_inode(
120 struct super_block *sb,
121 u64 ino,
122 u32 generation)
123 {
124 xfs_mount_t *mp = XFS_M(sb);
125 xfs_inode_t *ip;
126 int error;
127
128 /*
129 * NFS can sometimes send requests for ino 0. Fail them gracefully.
130 */
131 if (ino == 0)
132 return ERR_PTR(-ESTALE);
133
134 /*
135 * The XFS_IGET_UNTRUSTED means that an invalid inode number is just
136 * fine and not an indication of a corrupted filesystem as clients can
137 * send invalid file handles and we have to handle it gracefully..
138 */
139 error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
140 if (error) {
141 /*
142 * EINVAL means the inode cluster doesn't exist anymore.
143 * This implies the filehandle is stale, so we should
144 * translate it here.
145 * We don't use ESTALE directly down the chain to not
146 * confuse applications using bulkstat that expect EINVAL.
147 */
148 if (error == EINVAL || error == ENOENT)
149 error = ESTALE;
150 return ERR_PTR(-error);
151 }
152
153 if (ip->i_d.di_gen != generation) {
154 IRELE(ip);
155 return ERR_PTR(-ESTALE);
156 }
157
158 return VFS_I(ip);
159}
160
161STATIC struct dentry *
162xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
163 int fh_len, int fileid_type)
164{
165 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
166 struct inode *inode = NULL;
167
168 if (fh_len < xfs_fileid_length(fileid_type))
169 return NULL;
170
171 switch (fileid_type) {
172 case FILEID_INO32_GEN_PARENT:
173 case FILEID_INO32_GEN:
174 inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
175 break;
176 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
177 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
178 inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
179 break;
180 }
181
182 return d_obtain_alias(inode);
183}
184
185STATIC struct dentry *
186xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
187 int fh_len, int fileid_type)
188{
189 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
190 struct inode *inode = 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(child->d_inode), &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};
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_pnfs.h"
19
20/*
21 * Note that we only accept fileids which are long enough rather than allow
22 * the parent generation number to default to zero. XFS considers zero a
23 * valid generation number not an invalid/wildcard value.
24 */
25static int xfs_fileid_length(int fileid_type)
26{
27 switch (fileid_type) {
28 case FILEID_INO32_GEN:
29 return 2;
30 case FILEID_INO32_GEN_PARENT:
31 return 4;
32 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
33 return 3;
34 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
35 return 6;
36 }
37 return FILEID_INVALID;
38}
39
40STATIC int
41xfs_fs_encode_fh(
42 struct inode *inode,
43 __u32 *fh,
44 int *max_len,
45 struct inode *parent)
46{
47 struct xfs_mount *mp = XFS_M(inode->i_sb);
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 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_has_small_inums(mp) || xfs_is_inode32(mp))
68 fileid_type |= XFS_FILEID_TYPE_64FLAG;
69
70 /*
71 * Only encode if there is enough space given. In practice
72 * this means we can't export a filesystem with 64bit inodes
73 * over NFSv2 with the subtree_check export option; the other
74 * seven combinations work. The real answer is "don't use v2".
75 */
76 len = xfs_fileid_length(fileid_type);
77 if (*max_len < len) {
78 *max_len = len;
79 return FILEID_INVALID;
80 }
81 *max_len = len;
82
83 switch (fileid_type) {
84 case FILEID_INO32_GEN_PARENT:
85 fid->i32.parent_ino = XFS_I(parent)->i_ino;
86 fid->i32.parent_gen = parent->i_generation;
87 fallthrough;
88 case FILEID_INO32_GEN:
89 fid->i32.ino = XFS_I(inode)->i_ino;
90 fid->i32.gen = inode->i_generation;
91 break;
92 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
93 fid64->parent_ino = XFS_I(parent)->i_ino;
94 fid64->parent_gen = parent->i_generation;
95 fallthrough;
96 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
97 fid64->ino = XFS_I(inode)->i_ino;
98 fid64->gen = inode->i_generation;
99 break;
100 }
101
102 return fileid_type;
103}
104
105struct inode *
106xfs_nfs_get_inode(
107 struct super_block *sb,
108 u64 ino,
109 u32 generation)
110{
111 xfs_mount_t *mp = XFS_M(sb);
112 xfs_inode_t *ip;
113 int error;
114
115 /*
116 * NFS can sometimes send requests for ino 0. Fail them gracefully.
117 */
118 if (ino == 0)
119 return ERR_PTR(-ESTALE);
120
121 /*
122 * The XFS_IGET_UNTRUSTED means that an invalid inode number is just
123 * fine and not an indication of a corrupted filesystem as clients can
124 * send invalid file handles and we have to handle it gracefully..
125 */
126 error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
127 if (error) {
128
129 /*
130 * EINVAL means the inode cluster doesn't exist anymore.
131 * EFSCORRUPTED means the metadata pointing to the inode cluster
132 * or the inode cluster itself is corrupt. This implies the
133 * filehandle is stale, so we should translate it here.
134 * We don't use ESTALE directly down the chain to not
135 * confuse applications using bulkstat that expect EINVAL.
136 */
137 switch (error) {
138 case -EINVAL:
139 case -ENOENT:
140 case -EFSCORRUPTED:
141 error = -ESTALE;
142 break;
143 default:
144 break;
145 }
146 return ERR_PTR(error);
147 }
148
149 /*
150 * Reload the incore unlinked list to avoid failure in inodegc.
151 * Use an unlocked check here because unrecovered unlinked inodes
152 * should be somewhat rare.
153 */
154 if (xfs_inode_unlinked_incomplete(ip)) {
155 error = xfs_inode_reload_unlinked(ip);
156 if (error) {
157 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
158 xfs_irele(ip);
159 return ERR_PTR(error);
160 }
161 }
162
163 if (VFS_I(ip)->i_generation != generation || IS_PRIVATE(VFS_I(ip))) {
164 xfs_irele(ip);
165 return ERR_PTR(-ESTALE);
166 }
167
168 return VFS_I(ip);
169}
170
171STATIC struct dentry *
172xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
173 int fh_len, int fileid_type)
174{
175 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
176 struct inode *inode = NULL;
177
178 if (fh_len < xfs_fileid_length(fileid_type))
179 return NULL;
180
181 switch (fileid_type) {
182 case FILEID_INO32_GEN_PARENT:
183 case FILEID_INO32_GEN:
184 inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
185 break;
186 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
187 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
188 inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
189 break;
190 }
191
192 return d_obtain_alias(inode);
193}
194
195STATIC struct dentry *
196xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
197 int fh_len, int fileid_type)
198{
199 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
200 struct inode *inode = NULL;
201
202 if (fh_len < xfs_fileid_length(fileid_type))
203 return NULL;
204
205 switch (fileid_type) {
206 case FILEID_INO32_GEN_PARENT:
207 inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
208 fid->i32.parent_gen);
209 break;
210 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
211 inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
212 fid64->parent_gen);
213 break;
214 }
215
216 return d_obtain_alias(inode);
217}
218
219STATIC struct dentry *
220xfs_fs_get_parent(
221 struct dentry *child)
222{
223 int error;
224 struct xfs_inode *cip;
225
226 error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL);
227 if (unlikely(error))
228 return ERR_PTR(error);
229
230 return d_obtain_alias(VFS_I(cip));
231}
232
233STATIC int
234xfs_fs_nfs_commit_metadata(
235 struct inode *inode)
236{
237 return xfs_log_force_inode(XFS_I(inode));
238}
239
240const struct export_operations xfs_export_operations = {
241 .encode_fh = xfs_fs_encode_fh,
242 .fh_to_dentry = xfs_fs_fh_to_dentry,
243 .fh_to_parent = xfs_fs_fh_to_parent,
244 .get_parent = xfs_fs_get_parent,
245 .commit_metadata = xfs_fs_nfs_commit_metadata,
246#ifdef CONFIG_EXPORTFS_BLOCK_OPS
247 .get_uuid = xfs_fs_get_uuid,
248 .map_blocks = xfs_fs_map_blocks,
249 .commit_blocks = xfs_fs_commit_blocks,
250#endif
251};