1 /* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * export.c 5 * 6 * Functions to facilitate NFS exporting 7 * 8 * Copyright (C) 2002, 2005 Oracle. All rights reserved. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public 12 * License as published by the Free Software Foundation; either 13 * version 2 of the License, or (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public 21 * License along with this program; if not, write to the 22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 23 * Boston, MA 021110-1307, USA. 24 */ 25 26 #include <linux/fs.h> 27 #include <linux/types.h> 28 29 #include <cluster/masklog.h> 30 31 #include "ocfs2.h" 32 33 #include "alloc.h" 34 #include "dir.h" 35 #include "dlmglue.h" 36 #include "dcache.h" 37 #include "export.h" 38 #include "inode.h" 39 40 #include "buffer_head_io.h" 41 #include "suballoc.h" 42 #include "ocfs2_trace.h" 43 44 struct ocfs2_inode_handle 45 { 46 u64 ih_blkno; 47 u32 ih_generation; 48 }; 49 50 static struct dentry *ocfs2_get_dentry(struct super_block *sb, 51 struct ocfs2_inode_handle *handle) 52 { 53 struct inode *inode; 54 struct ocfs2_super *osb = OCFS2_SB(sb); 55 u64 blkno = handle->ih_blkno; 56 int status, set; 57 struct dentry *result; 58 59 trace_ocfs2_get_dentry_begin(sb, handle, (unsigned long long)blkno); 60 61 if (blkno == 0) { 62 result = ERR_PTR(-ESTALE); 63 goto bail; 64 } 65 66 inode = ocfs2_ilookup(sb, blkno); 67 /* 68 * If the inode exists in memory, we only need to check it's 69 * generation number 70 */ 71 if (inode) 72 goto check_gen; 73 74 /* 75 * This will synchronize us against ocfs2_delete_inode() on 76 * all nodes 77 */ 78 status = ocfs2_nfs_sync_lock(osb, 1); 79 if (status < 0) { 80 mlog(ML_ERROR, "getting nfs sync lock(EX) failed %d\n", status); 81 goto check_err; 82 } 83 84 status = ocfs2_test_inode_bit(osb, blkno, &set); 85 if (status < 0) { 86 if (status == -EINVAL) { 87 /* 88 * The blkno NFS gave us doesn't even show up 89 * as an inode, we return -ESTALE to be 90 * nice 91 */ 92 status = -ESTALE; 93 } else 94 mlog(ML_ERROR, "test inode bit failed %d\n", status); 95 goto unlock_nfs_sync; 96 } 97 98 trace_ocfs2_get_dentry_test_bit(status, set); 99 /* If the inode allocator bit is clear, this inode must be stale */ 100 if (!set) { 101 status = -ESTALE; 102 goto unlock_nfs_sync; 103 } 104 105 inode = ocfs2_iget(osb, blkno, 0, 0); 106 107 unlock_nfs_sync: 108 ocfs2_nfs_sync_unlock(osb, 1); 109 110 check_err: 111 if (status < 0) { 112 if (status == -ESTALE) { 113 trace_ocfs2_get_dentry_stale((unsigned long long)blkno, 114 handle->ih_generation); 115 } 116 result = ERR_PTR(status); 117 goto bail; 118 } 119 120 if (IS_ERR(inode)) { 121 mlog_errno(PTR_ERR(inode)); 122 result = (void *)inode; 123 goto bail; 124 } 125 126 check_gen: 127 if (handle->ih_generation != inode->i_generation) { 128 iput(inode); 129 trace_ocfs2_get_dentry_generation((unsigned long long)blkno, 130 handle->ih_generation, 131 inode->i_generation); 132 result = ERR_PTR(-ESTALE); 133 goto bail; 134 } 135 136 result = d_obtain_alias(inode); 137 if (IS_ERR(result)) 138 mlog_errno(PTR_ERR(result)); 139 140 bail: 141 trace_ocfs2_get_dentry_end(result); 142 return result; 143 } 144 145 static struct dentry *ocfs2_get_parent(struct dentry *child) 146 { 147 int status; 148 u64 blkno; 149 struct dentry *parent; 150 struct inode *dir = d_inode(child); 151 152 trace_ocfs2_get_parent(child, child->d_name.len, child->d_name.name, 153 (unsigned long long)OCFS2_I(dir)->ip_blkno); 154 155 status = ocfs2_inode_lock(dir, NULL, 0); 156 if (status < 0) { 157 if (status != -ENOENT) 158 mlog_errno(status); 159 parent = ERR_PTR(status); 160 goto bail; 161 } 162 163 status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno); 164 if (status < 0) { 165 parent = ERR_PTR(-ENOENT); 166 goto bail_unlock; 167 } 168 169 parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0)); 170 171 bail_unlock: 172 ocfs2_inode_unlock(dir, 0); 173 174 bail: 175 trace_ocfs2_get_parent_end(parent); 176 177 return parent; 178 } 179 180 static int ocfs2_encode_fh(struct inode *inode, u32 *fh_in, int *max_len, 181 struct inode *parent) 182 { 183 int len = *max_len; 184 int type = 1; 185 u64 blkno; 186 u32 generation; 187 __le32 *fh = (__force __le32 *) fh_in; 188 189 #ifdef TRACE_HOOKS_ARE_NOT_BRAINDEAD_IN_YOUR_OPINION 190 #error "You go ahead and fix that mess, then. Somehow" 191 trace_ocfs2_encode_fh_begin(dentry, dentry->d_name.len, 192 dentry->d_name.name, 193 fh, len, connectable); 194 #endif 195 196 if (parent && (len < 6)) { 197 *max_len = 6; 198 type = FILEID_INVALID; 199 goto bail; 200 } else if (len < 3) { 201 *max_len = 3; 202 type = FILEID_INVALID; 203 goto bail; 204 } 205 206 blkno = OCFS2_I(inode)->ip_blkno; 207 generation = inode->i_generation; 208 209 trace_ocfs2_encode_fh_self((unsigned long long)blkno, generation); 210 211 len = 3; 212 fh[0] = cpu_to_le32((u32)(blkno >> 32)); 213 fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff)); 214 fh[2] = cpu_to_le32(generation); 215 216 if (parent) { 217 blkno = OCFS2_I(parent)->ip_blkno; 218 generation = parent->i_generation; 219 220 fh[3] = cpu_to_le32((u32)(blkno >> 32)); 221 fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff)); 222 fh[5] = cpu_to_le32(generation); 223 224 len = 6; 225 type = 2; 226 227 trace_ocfs2_encode_fh_parent((unsigned long long)blkno, 228 generation); 229 } 230 231 *max_len = len; 232 233 bail: 234 trace_ocfs2_encode_fh_type(type); 235 return type; 236 } 237 238 static struct dentry *ocfs2_fh_to_dentry(struct super_block *sb, 239 struct fid *fid, int fh_len, int fh_type) 240 { 241 struct ocfs2_inode_handle handle; 242 243 if (fh_len < 3 || fh_type > 2) 244 return NULL; 245 246 handle.ih_blkno = (u64)le32_to_cpu(fid->raw[0]) << 32; 247 handle.ih_blkno |= (u64)le32_to_cpu(fid->raw[1]); 248 handle.ih_generation = le32_to_cpu(fid->raw[2]); 249 return ocfs2_get_dentry(sb, &handle); 250 } 251 252 static struct dentry *ocfs2_fh_to_parent(struct super_block *sb, 253 struct fid *fid, int fh_len, int fh_type) 254 { 255 struct ocfs2_inode_handle parent; 256 257 if (fh_type != 2 || fh_len < 6) 258 return NULL; 259 260 parent.ih_blkno = (u64)le32_to_cpu(fid->raw[3]) << 32; 261 parent.ih_blkno |= (u64)le32_to_cpu(fid->raw[4]); 262 parent.ih_generation = le32_to_cpu(fid->raw[5]); 263 return ocfs2_get_dentry(sb, &parent); 264 } 265 266 const struct export_operations ocfs2_export_ops = { 267 .encode_fh = ocfs2_encode_fh, 268 .fh_to_dentry = ocfs2_fh_to_dentry, 269 .fh_to_parent = ocfs2_fh_to_parent, 270 .get_parent = ocfs2_get_parent, 271 }; 272