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