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 */ 38 static 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 53 STATIC int 54 xfs_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 } 117 118 STATIC struct inode * 119 xfs_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 } 160 161 STATIC struct dentry * 162 xfs_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 } 184 185 STATIC struct dentry * 186 xfs_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 } 205 206 STATIC struct dentry * 207 xfs_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 } 219 220 STATIC int 221 xfs_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 } 237 238 const 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 }; 245