ARM: 7073/1: debug: augment DEBUG_LL Kconfig help to clarify behaviour
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / xfs / xfs_export.c
blob75e5d322e48fcd6a6bb2b604b049aac3c07cfd37
1 /*
2 * Copyright (c) 2004-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
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
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"
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.
39 static int xfs_fileid_length(int fileid_type)
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;
51 return 255; /* invalid */
54 STATIC int
55 xfs_fs_encode_fh(
56 struct dentry *dentry,
57 __u32 *fh,
58 int *max_len,
59 int connectable)
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;
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;
74 * If the the filesystem may contain 64bit inode numbers, we need
75 * to use larger file handles that can represent them.
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.
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;
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".
91 len = xfs_fileid_length(fileid_type);
92 if (*max_len < len) {
93 *max_len = len;
94 return 255;
96 *max_len = len;
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;
121 return fileid_type;
124 STATIC struct inode *
125 xfs_nfs_get_inode(
126 struct super_block *sb,
127 u64 ino,
128 u32 generation)
130 xfs_mount_t *mp = XFS_M(sb);
131 xfs_inode_t *ip;
132 int error;
135 * NFS can sometimes send requests for ino 0. Fail them gracefully.
137 if (ino == 0)
138 return ERR_PTR(-ESTALE);
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..
145 error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
146 if (error) {
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.
154 if (error == EINVAL || error == ENOENT)
155 error = ESTALE;
156 return ERR_PTR(-error);
159 if (ip->i_d.di_gen != generation) {
160 IRELE(ip);
161 return ERR_PTR(-ESTALE);
164 return VFS_I(ip);
167 STATIC struct dentry *
168 xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
169 int fh_len, int fileid_type)
171 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
172 struct inode *inode = NULL;
174 if (fh_len < xfs_fileid_length(fileid_type))
175 return NULL;
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;
188 return d_obtain_alias(inode);
191 STATIC struct dentry *
192 xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
193 int fh_len, int fileid_type)
195 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
196 struct inode *inode = NULL;
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;
209 return d_obtain_alias(inode);
212 STATIC struct dentry *
213 xfs_fs_get_parent(
214 struct dentry *child)
216 int error;
217 struct xfs_inode *cip;
219 error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
220 if (unlikely(error))
221 return ERR_PTR(-error);
223 return d_obtain_alias(VFS_I(cip));
226 STATIC int
227 xfs_fs_nfs_commit_metadata(
228 struct inode *inode)
230 struct xfs_inode *ip = XFS_I(inode);
231 struct xfs_mount *mp = ip->i_mount;
232 int error = 0;
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);
239 xfs_iunlock(ip, XFS_ILOCK_SHARED);
241 return error;
244 const 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,