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 #define MLOG_MASK_PREFIX ML_EXPORT 30 #include <cluster/masklog.h> 31 32 #include "ocfs2.h" 33 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 42 struct ocfs2_inode_handle 43 { 44 u64 ih_blkno; 45 u32 ih_generation; 46 }; 47 48 static struct dentry *ocfs2_get_dentry(struct super_block *sb, void *vobjp) 49 { 50 struct ocfs2_inode_handle *handle = vobjp; 51 struct inode *inode; 52 struct dentry *result; 53 54 mlog_entry("(0x%p, 0x%p)\n", sb, handle); 55 56 if (handle->ih_blkno == 0) { 57 mlog_errno(-ESTALE); 58 return ERR_PTR(-ESTALE); 59 } 60 61 inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno, 0); 62 63 if (IS_ERR(inode)) 64 return (void *)inode; 65 66 if (handle->ih_generation != inode->i_generation) { 67 iput(inode); 68 return ERR_PTR(-ESTALE); 69 } 70 71 result = d_alloc_anon(inode); 72 73 if (!result) { 74 iput(inode); 75 mlog_errno(-ENOMEM); 76 return ERR_PTR(-ENOMEM); 77 } 78 result->d_op = &ocfs2_dentry_ops; 79 80 mlog_exit_ptr(result); 81 return result; 82 } 83 84 static struct dentry *ocfs2_get_parent(struct dentry *child) 85 { 86 int status; 87 u64 blkno; 88 struct dentry *parent; 89 struct inode *inode; 90 struct inode *dir = child->d_inode; 91 92 mlog_entry("(0x%p, '%.*s')\n", child, 93 child->d_name.len, child->d_name.name); 94 95 mlog(0, "find parent of directory %llu\n", 96 (unsigned long long)OCFS2_I(dir)->ip_blkno); 97 98 status = ocfs2_meta_lock(dir, NULL, 0); 99 if (status < 0) { 100 if (status != -ENOENT) 101 mlog_errno(status); 102 parent = ERR_PTR(status); 103 goto bail; 104 } 105 106 status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno); 107 if (status < 0) { 108 parent = ERR_PTR(-ENOENT); 109 goto bail_unlock; 110 } 111 112 inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0); 113 if (IS_ERR(inode)) { 114 mlog(ML_ERROR, "Unable to create inode %llu\n", 115 (unsigned long long)blkno); 116 parent = ERR_PTR(-EACCES); 117 goto bail_unlock; 118 } 119 120 parent = d_alloc_anon(inode); 121 if (!parent) { 122 iput(inode); 123 parent = ERR_PTR(-ENOMEM); 124 } 125 126 parent->d_op = &ocfs2_dentry_ops; 127 128 bail_unlock: 129 ocfs2_meta_unlock(dir, 0); 130 131 bail: 132 mlog_exit_ptr(parent); 133 134 return parent; 135 } 136 137 static int ocfs2_encode_fh(struct dentry *dentry, u32 *fh_in, int *max_len, 138 int connectable) 139 { 140 struct inode *inode = dentry->d_inode; 141 int len = *max_len; 142 int type = 1; 143 u64 blkno; 144 u32 generation; 145 __le32 *fh = (__force __le32 *) fh_in; 146 147 mlog_entry("(0x%p, '%.*s', 0x%p, %d, %d)\n", dentry, 148 dentry->d_name.len, dentry->d_name.name, 149 fh, len, connectable); 150 151 if (len < 3 || (connectable && len < 6)) { 152 mlog(ML_ERROR, "fh buffer is too small for encoding\n"); 153 type = 255; 154 goto bail; 155 } 156 157 blkno = OCFS2_I(inode)->ip_blkno; 158 generation = inode->i_generation; 159 160 mlog(0, "Encoding fh: blkno: %llu, generation: %u\n", 161 (unsigned long long)blkno, generation); 162 163 len = 3; 164 fh[0] = cpu_to_le32((u32)(blkno >> 32)); 165 fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff)); 166 fh[2] = cpu_to_le32(generation); 167 168 if (connectable && !S_ISDIR(inode->i_mode)) { 169 struct inode *parent; 170 171 spin_lock(&dentry->d_lock); 172 173 parent = dentry->d_parent->d_inode; 174 blkno = OCFS2_I(parent)->ip_blkno; 175 generation = parent->i_generation; 176 177 fh[3] = cpu_to_le32((u32)(blkno >> 32)); 178 fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff)); 179 fh[5] = cpu_to_le32(generation); 180 181 spin_unlock(&dentry->d_lock); 182 183 len = 6; 184 type = 2; 185 186 mlog(0, "Encoding parent: blkno: %llu, generation: %u\n", 187 (unsigned long long)blkno, generation); 188 } 189 190 *max_len = len; 191 192 bail: 193 mlog_exit(type); 194 return type; 195 } 196 197 static struct dentry *ocfs2_decode_fh(struct super_block *sb, u32 *fh_in, 198 int fh_len, int fileid_type, 199 int (*acceptable)(void *context, 200 struct dentry *de), 201 void *context) 202 { 203 struct ocfs2_inode_handle handle, parent; 204 struct dentry *ret = NULL; 205 __le32 *fh = (__force __le32 *) fh_in; 206 207 mlog_entry("(0x%p, 0x%p, %d, %d, 0x%p, 0x%p)\n", 208 sb, fh, fh_len, fileid_type, acceptable, context); 209 210 if (fh_len < 3 || fileid_type > 2) 211 goto bail; 212 213 if (fileid_type == 2) { 214 if (fh_len < 6) 215 goto bail; 216 217 parent.ih_blkno = (u64)le32_to_cpu(fh[3]) << 32; 218 parent.ih_blkno |= (u64)le32_to_cpu(fh[4]); 219 parent.ih_generation = le32_to_cpu(fh[5]); 220 221 mlog(0, "Decoding parent: blkno: %llu, generation: %u\n", 222 (unsigned long long)parent.ih_blkno, 223 parent.ih_generation); 224 } 225 226 handle.ih_blkno = (u64)le32_to_cpu(fh[0]) << 32; 227 handle.ih_blkno |= (u64)le32_to_cpu(fh[1]); 228 handle.ih_generation = le32_to_cpu(fh[2]); 229 230 mlog(0, "Encoding fh: blkno: %llu, generation: %u\n", 231 (unsigned long long)handle.ih_blkno, handle.ih_generation); 232 233 ret = ocfs2_export_ops.find_exported_dentry(sb, &handle, &parent, 234 acceptable, context); 235 236 bail: 237 mlog_exit_ptr(ret); 238 return ret; 239 } 240 241 struct export_operations ocfs2_export_ops = { 242 .decode_fh = ocfs2_decode_fh, 243 .encode_fh = ocfs2_encode_fh, 244 245 .get_parent = ocfs2_get_parent, 246 .get_dentry = ocfs2_get_dentry, 247 }; 248