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 */ 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 255; /* invalid */ 52 } 53 54 STATIC int 55 xfs_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 } 123 124 STATIC struct inode * 125 xfs_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 } 166 167 STATIC struct dentry * 168 xfs_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 } 190 191 STATIC struct dentry * 192 xfs_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 } 211 212 STATIC struct dentry * 213 xfs_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 } 225 226 STATIC int 227 xfs_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 xfs_lsn_t lsn = 0; 233 234 xfs_ilock(ip, XFS_ILOCK_SHARED); 235 if (xfs_ipincount(ip)) 236 lsn = ip->i_itemp->ili_last_lsn; 237 xfs_iunlock(ip, XFS_ILOCK_SHARED); 238 239 if (!lsn) 240 return 0; 241 return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL); 242 } 243 244 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, 250 }; 251