1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2004-2005 Silicon Graphics, Inc. 4 * All Rights Reserved. 5 */ 6 #include "xfs.h" 7 #include "xfs_format.h" 8 #include "xfs_log_format.h" 9 #include "xfs_trans_resv.h" 10 #include "xfs_mount.h" 11 #include "xfs_da_format.h" 12 #include "xfs_da_btree.h" 13 #include "xfs_dir2.h" 14 #include "xfs_export.h" 15 #include "xfs_inode.h" 16 #include "xfs_trans.h" 17 #include "xfs_inode_item.h" 18 #include "xfs_trace.h" 19 #include "xfs_icache.h" 20 #include "xfs_log.h" 21 #include "xfs_pnfs.h" 22 23 /* 24 * Note that we only accept fileids which are long enough rather than allow 25 * the parent generation number to default to zero. XFS considers zero a 26 * valid generation number not an invalid/wildcard value. 27 */ 28 static int xfs_fileid_length(int fileid_type) 29 { 30 switch (fileid_type) { 31 case FILEID_INO32_GEN: 32 return 2; 33 case FILEID_INO32_GEN_PARENT: 34 return 4; 35 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: 36 return 3; 37 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: 38 return 6; 39 } 40 return FILEID_INVALID; 41 } 42 43 STATIC int 44 xfs_fs_encode_fh( 45 struct inode *inode, 46 __u32 *fh, 47 int *max_len, 48 struct inode *parent) 49 { 50 struct fid *fid = (struct fid *)fh; 51 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh; 52 int fileid_type; 53 int len; 54 55 /* Directories don't need their parent encoded, they have ".." */ 56 if (!parent) 57 fileid_type = FILEID_INO32_GEN; 58 else 59 fileid_type = FILEID_INO32_GEN_PARENT; 60 61 /* 62 * If the the filesystem may contain 64bit inode numbers, we need 63 * to use larger file handles that can represent them. 64 * 65 * While we only allocate inodes that do not fit into 32 bits any 66 * large enough filesystem may contain them, thus the slightly 67 * confusing looking conditional below. 68 */ 69 if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) || 70 (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES)) 71 fileid_type |= XFS_FILEID_TYPE_64FLAG; 72 73 /* 74 * Only encode if there is enough space given. In practice 75 * this means we can't export a filesystem with 64bit inodes 76 * over NFSv2 with the subtree_check export option; the other 77 * seven combinations work. The real answer is "don't use v2". 78 */ 79 len = xfs_fileid_length(fileid_type); 80 if (*max_len < len) { 81 *max_len = len; 82 return FILEID_INVALID; 83 } 84 *max_len = len; 85 86 switch (fileid_type) { 87 case FILEID_INO32_GEN_PARENT: 88 fid->i32.parent_ino = XFS_I(parent)->i_ino; 89 fid->i32.parent_gen = parent->i_generation; 90 /*FALLTHRU*/ 91 case FILEID_INO32_GEN: 92 fid->i32.ino = XFS_I(inode)->i_ino; 93 fid->i32.gen = inode->i_generation; 94 break; 95 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: 96 fid64->parent_ino = XFS_I(parent)->i_ino; 97 fid64->parent_gen = parent->i_generation; 98 /*FALLTHRU*/ 99 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: 100 fid64->ino = XFS_I(inode)->i_ino; 101 fid64->gen = inode->i_generation; 102 break; 103 } 104 105 return fileid_type; 106 } 107 108 STATIC struct inode * 109 xfs_nfs_get_inode( 110 struct super_block *sb, 111 u64 ino, 112 u32 generation) 113 { 114 xfs_mount_t *mp = XFS_M(sb); 115 xfs_inode_t *ip; 116 int error; 117 118 /* 119 * NFS can sometimes send requests for ino 0. Fail them gracefully. 120 */ 121 if (ino == 0) 122 return ERR_PTR(-ESTALE); 123 124 /* 125 * The XFS_IGET_UNTRUSTED means that an invalid inode number is just 126 * fine and not an indication of a corrupted filesystem as clients can 127 * send invalid file handles and we have to handle it gracefully.. 128 */ 129 error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip); 130 if (error) { 131 132 /* 133 * EINVAL means the inode cluster doesn't exist anymore. 134 * EFSCORRUPTED means the metadata pointing to the inode cluster 135 * or the inode cluster itself is corrupt. This implies the 136 * filehandle is stale, so we should translate it here. 137 * We don't use ESTALE directly down the chain to not 138 * confuse applications using bulkstat that expect EINVAL. 139 */ 140 switch (error) { 141 case -EINVAL: 142 case -ENOENT: 143 case -EFSCORRUPTED: 144 error = -ESTALE; 145 break; 146 default: 147 break; 148 } 149 return ERR_PTR(error); 150 } 151 152 if (VFS_I(ip)->i_generation != generation) { 153 IRELE(ip); 154 return ERR_PTR(-ESTALE); 155 } 156 157 return VFS_I(ip); 158 } 159 160 STATIC struct dentry * 161 xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid, 162 int fh_len, int fileid_type) 163 { 164 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; 165 struct inode *inode = NULL; 166 167 if (fh_len < xfs_fileid_length(fileid_type)) 168 return NULL; 169 170 switch (fileid_type) { 171 case FILEID_INO32_GEN_PARENT: 172 case FILEID_INO32_GEN: 173 inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen); 174 break; 175 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: 176 case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG: 177 inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen); 178 break; 179 } 180 181 return d_obtain_alias(inode); 182 } 183 184 STATIC struct dentry * 185 xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid, 186 int fh_len, int fileid_type) 187 { 188 struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid; 189 struct inode *inode = NULL; 190 191 if (fh_len < xfs_fileid_length(fileid_type)) 192 return NULL; 193 194 switch (fileid_type) { 195 case FILEID_INO32_GEN_PARENT: 196 inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino, 197 fid->i32.parent_gen); 198 break; 199 case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG: 200 inode = xfs_nfs_get_inode(sb, fid64->parent_ino, 201 fid64->parent_gen); 202 break; 203 } 204 205 return d_obtain_alias(inode); 206 } 207 208 STATIC struct dentry * 209 xfs_fs_get_parent( 210 struct dentry *child) 211 { 212 int error; 213 struct xfs_inode *cip; 214 215 error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL); 216 if (unlikely(error)) 217 return ERR_PTR(error); 218 219 return d_obtain_alias(VFS_I(cip)); 220 } 221 222 STATIC int 223 xfs_fs_nfs_commit_metadata( 224 struct inode *inode) 225 { 226 struct xfs_inode *ip = XFS_I(inode); 227 struct xfs_mount *mp = ip->i_mount; 228 xfs_lsn_t lsn = 0; 229 230 xfs_ilock(ip, XFS_ILOCK_SHARED); 231 if (xfs_ipincount(ip)) 232 lsn = ip->i_itemp->ili_last_lsn; 233 xfs_iunlock(ip, XFS_ILOCK_SHARED); 234 235 if (!lsn) 236 return 0; 237 return xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL); 238 } 239 240 const struct export_operations xfs_export_operations = { 241 .encode_fh = xfs_fs_encode_fh, 242 .fh_to_dentry = xfs_fs_fh_to_dentry, 243 .fh_to_parent = xfs_fs_fh_to_parent, 244 .get_parent = xfs_fs_get_parent, 245 .commit_metadata = xfs_fs_nfs_commit_metadata, 246 #ifdef CONFIG_EXPORTFS_BLOCK_OPS 247 .get_uuid = xfs_fs_get_uuid, 248 .map_blocks = xfs_fs_map_blocks, 249 .commit_blocks = xfs_fs_commit_blocks, 250 #endif 251 }; 252