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 #include "xfs_pnfs.h" 34 35 /* 36 * Note that we only accept fileids which are long enough rather than allow 37 * the parent generation number to default to zero. XFS considers zero a 38 * valid generation number not an invalid/wildcard value. 39 */ 40 static int xfs_fileid_length(int fileid_type) 41 { 42 switch (fileid_type) { 43 case FILEID_INO32_GEN: 44 return 2; 45 case FILEID_INO32_GEN_PARENT: 46 return 4; 47 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: 48 return 3; 49 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: 50 return 6; 51 } 52 return FILEID_INVALID; 53 } 54 55 STATIC int 56 xfs_fs_encode_fh( 57 struct inode *inode, 58 __u32 *fh, 59 int *max_len, 60 struct inode *parent) 61 { 62 struct fid *fid = (struct fid *)fh; 63 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh; 64 int fileid_type; 65 int len; 66 67 /* Directories don't need their parent encoded, they have ".." */ 68 if (!parent) 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 FILEID_INVALID; 95 } 96 *max_len = len; 97 98 switch (fileid_type) { 99 case FILEID_INO32_GEN_PARENT: 100 fid->i32.parent_ino = XFS_I(parent)->i_ino; 101 fid->i32.parent_gen = parent->i_generation; 102 /*FALLTHRU*/ 103 case FILEID_INO32_GEN: 104 fid->i32.ino = XFS_I(inode)->i_ino; 105 fid->i32.gen = inode->i_generation; 106 break; 107 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: 108 fid64->parent_ino = XFS_I(parent)->i_ino; 109 fid64->parent_gen = parent->i_generation; 110 /*FALLTHRU*/ 111 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: 112 fid64->ino = XFS_I(inode)->i_ino; 113 fid64->gen = inode->i_generation; 114 break; 115 } 116 117 return fileid_type; 118 } 119 120 STATIC struct inode * 121 xfs_nfs_get_inode( 122 struct super_block *sb, 123 u64 ino, 124 u32 generation) 125 { 126 xfs_mount_t *mp = XFS_M(sb); 127 xfs_inode_t *ip; 128 int error; 129 130 /* 131 * NFS can sometimes send requests for ino 0. Fail them gracefully. 132 */ 133 if (ino == 0) 134 return ERR_PTR(-ESTALE); 135 136 /* 137 * The XFS_IGET_UNTRUSTED means that an invalid inode number is just 138 * fine and not an indication of a corrupted filesystem as clients can 139 * send invalid file handles and we have to handle it gracefully.. 140 */ 141 error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip); 142 if (error) { 143 /* 144 * EINVAL means the inode cluster doesn't exist anymore. 145 * This implies the filehandle is stale, so we should 146 * translate it here. 147 * We don't use ESTALE directly down the chain to not 148 * confuse applications using bulkstat that expect EINVAL. 149 */ 150 if (error == -EINVAL || error == -ENOENT) 151 error = -ESTALE; 152 return ERR_PTR(error); 153 } 154 155 if (ip->i_d.di_gen != generation) { 156 IRELE(ip); 157 return ERR_PTR(-ESTALE); 158 } 159 160 return VFS_I(ip); 161 } 162 163 STATIC struct dentry * 164 xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid, 165 int fh_len, int fileid_type) 166 { 167 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; 168 struct inode *inode = NULL; 169 170 if (fh_len < xfs_fileid_length(fileid_type)) 171 return NULL; 172 173 switch (fileid_type) { 174 case FILEID_INO32_GEN_PARENT: 175 case FILEID_INO32_GEN: 176 inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen); 177 break; 178 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: 179 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: 180 inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen); 181 break; 182 } 183 184 return d_obtain_alias(inode); 185 } 186 187 STATIC struct dentry * 188 xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid, 189 int fh_len, int fileid_type) 190 { 191 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; 192 struct inode *inode = NULL; 193 194 if (fh_len < xfs_fileid_length(fileid_type)) 195 return NULL; 196 197 switch (fileid_type) { 198 case FILEID_INO32_GEN_PARENT: 199 inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino, 200 fid->i32.parent_gen); 201 break; 202 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: 203 inode = xfs_nfs_get_inode(sb, fid64->parent_ino, 204 fid64->parent_gen); 205 break; 206 } 207 208 return d_obtain_alias(inode); 209 } 210 211 STATIC struct dentry * 212 xfs_fs_get_parent( 213 struct dentry *child) 214 { 215 int error; 216 struct xfs_inode *cip; 217 218 error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL); 219 if (unlikely(error)) 220 return ERR_PTR(error); 221 222 return d_obtain_alias(VFS_I(cip)); 223 } 224 225 STATIC int 226 xfs_fs_nfs_commit_metadata( 227 struct inode *inode) 228 { 229 struct xfs_inode *ip = XFS_I(inode); 230 struct xfs_mount *mp = ip->i_mount; 231 xfs_lsn_t lsn = 0; 232 233 xfs_ilock(ip, XFS_ILOCK_SHARED); 234 if (xfs_ipincount(ip)) 235 lsn = ip->i_itemp->ili_last_lsn; 236 xfs_iunlock(ip, XFS_ILOCK_SHARED); 237 238 if (!lsn) 239 return 0; 240 return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL); 241 } 242 243 const struct export_operations xfs_export_operations = { 244 .encode_fh = xfs_fs_encode_fh, 245 .fh_to_dentry = xfs_fs_fh_to_dentry, 246 .fh_to_parent = xfs_fs_fh_to_parent, 247 .get_parent = xfs_fs_get_parent, 248 .commit_metadata = xfs_fs_nfs_commit_metadata, 249 #ifdef CONFIG_NFSD_PNFS 250 .get_uuid = xfs_fs_get_uuid, 251 .map_blocks = xfs_fs_map_blocks, 252 .commit_blocks = xfs_fs_commit_blocks, 253 #endif 254 }; 255