| 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 | #include "xfs_icache.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 | }; |