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 "export.h" 37 #include "inode.h" 38 39 #include "buffer_head_io.h" 40 41 struct ocfs2_inode_handle 42 { 43 u64 ih_blkno; 44 u32 ih_generation; 45 }; 46 47 static struct dentry *ocfs2_get_dentry(struct super_block *sb, void *vobjp) 48 { 49 struct ocfs2_inode_handle *handle = vobjp; 50 struct inode *inode; 51 struct dentry *result; 52 53 mlog_entry("(0x%p, 0x%p)\n", sb, handle); 54 55 if (handle->ih_blkno == 0) { 56 mlog_errno(-ESTALE); 57 return ERR_PTR(-ESTALE); 58 } 59 60 inode = ocfs2_iget(OCFS2_SB(sb), handle->ih_blkno); 61 62 if (IS_ERR(inode)) { 63 mlog_errno(PTR_ERR(inode)); 64 return (void *)inode; 65 } 66 67 if (handle->ih_generation != inode->i_generation) { 68 iput(inode); 69 mlog_errno(-ESTALE); 70 return ERR_PTR(-ESTALE); 71 } 72 73 result = d_alloc_anon(inode); 74 75 if (!result) { 76 iput(inode); 77 mlog_errno(-ENOMEM); 78 return ERR_PTR(-ENOMEM); 79 } 80 81 mlog_exit_ptr(result); 82 return result; 83 } 84 85 static struct dentry *ocfs2_get_parent(struct dentry *child) 86 { 87 int status; 88 u64 blkno; 89 struct dentry *parent; 90 struct inode *inode; 91 struct inode *dir = child->d_inode; 92 struct buffer_head *dirent_bh = NULL; 93 struct ocfs2_dir_entry *dirent; 94 95 mlog_entry("(0x%p, '%.*s')\n", child, 96 child->d_name.len, child->d_name.name); 97 98 mlog(0, "find parent of directory %"MLFu64"\n", 99 OCFS2_I(dir)->ip_blkno); 100 101 status = ocfs2_meta_lock(dir, NULL, NULL, 0); 102 if (status < 0) { 103 if (status != -ENOENT) 104 mlog_errno(status); 105 parent = ERR_PTR(status); 106 goto bail; 107 } 108 109 status = ocfs2_find_files_on_disk("..", 2, &blkno, dir, &dirent_bh, 110 &dirent); 111 if (status < 0) { 112 parent = ERR_PTR(-ENOENT); 113 goto bail_unlock; 114 } 115 116 inode = ocfs2_iget(OCFS2_SB(dir->i_sb), blkno); 117 if (IS_ERR(inode)) { 118 mlog(ML_ERROR, "Unable to create inode %"MLFu64"\n", blkno); 119 parent = ERR_PTR(-EACCES); 120 goto bail_unlock; 121 } 122 123 parent = d_alloc_anon(inode); 124 if (!parent) { 125 iput(inode); 126 parent = ERR_PTR(-ENOMEM); 127 } 128 129 bail_unlock: 130 ocfs2_meta_unlock(dir, 0); 131 132 if (dirent_bh) 133 brelse(dirent_bh); 134 135 bail: 136 mlog_exit_ptr(parent); 137 138 return parent; 139 } 140 141 static int ocfs2_encode_fh(struct dentry *dentry, __be32 *fh, int *max_len, 142 int connectable) 143 { 144 struct inode *inode = dentry->d_inode; 145 int len = *max_len; 146 int type = 1; 147 u64 blkno; 148 u32 generation; 149 150 mlog_entry("(0x%p, '%.*s', 0x%p, %d, %d)\n", dentry, 151 dentry->d_name.len, dentry->d_name.name, 152 fh, len, connectable); 153 154 if (len < 3 || (connectable && len < 6)) { 155 mlog(ML_ERROR, "fh buffer is too small for encoding\n"); 156 type = 255; 157 goto bail; 158 } 159 160 blkno = OCFS2_I(inode)->ip_blkno; 161 generation = inode->i_generation; 162 163 mlog(0, "Encoding fh: blkno: %"MLFu64", generation: %u\n", 164 blkno, generation); 165 166 len = 3; 167 fh[0] = cpu_to_le32((u32)(blkno >> 32)); 168 fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff)); 169 fh[2] = cpu_to_le32(generation); 170 171 if (connectable && !S_ISDIR(inode->i_mode)) { 172 struct inode *parent; 173 174 spin_lock(&dentry->d_lock); 175 176 parent = dentry->d_parent->d_inode; 177 blkno = OCFS2_I(parent)->ip_blkno; 178 generation = parent->i_generation; 179 180 fh[3] = cpu_to_le32((u32)(blkno >> 32)); 181 fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff)); 182 fh[5] = cpu_to_le32(generation); 183 184 spin_unlock(&dentry->d_lock); 185 186 len = 6; 187 type = 2; 188 189 mlog(0, "Encoding parent: blkno: %"MLFu64", generation: %u\n", 190 blkno, generation); 191 } 192 193 *max_len = len; 194 195 bail: 196 mlog_exit(type); 197 return type; 198 } 199 200 static struct dentry *ocfs2_decode_fh(struct super_block *sb, __be32 *fh, 201 int fh_len, int fileid_type, 202 int (*acceptable)(void *context, 203 struct dentry *de), 204 void *context) 205 { 206 struct ocfs2_inode_handle handle, parent; 207 struct dentry *ret = NULL; 208 209 mlog_entry("(0x%p, 0x%p, %d, %d, 0x%p, 0x%p)\n", 210 sb, fh, fh_len, fileid_type, acceptable, context); 211 212 if (fh_len < 3 || fileid_type > 2) 213 goto bail; 214 215 if (fileid_type == 2) { 216 if (fh_len < 6) 217 goto bail; 218 219 parent.ih_blkno = (u64)le32_to_cpu(fh[3]) << 32; 220 parent.ih_blkno |= (u64)le32_to_cpu(fh[4]); 221 parent.ih_generation = le32_to_cpu(fh[5]); 222 223 mlog(0, "Decoding parent: blkno: %"MLFu64", generation: %u\n", 224 parent.ih_blkno, parent.ih_generation); 225 } 226 227 handle.ih_blkno = (u64)le32_to_cpu(fh[0]) << 32; 228 handle.ih_blkno |= (u64)le32_to_cpu(fh[1]); 229 handle.ih_generation = le32_to_cpu(fh[2]); 230 231 mlog(0, "Encoding fh: blkno: %"MLFu64", generation: %u\n", 232 handle.ih_blkno, handle.ih_generation); 233 234 ret = ocfs2_export_ops.find_exported_dentry(sb, &handle, &parent, 235 acceptable, context); 236 237 bail: 238 mlog_exit_ptr(ret); 239 return ret; 240 } 241 242 struct export_operations ocfs2_export_ops = { 243 .decode_fh = ocfs2_decode_fh, 244 .encode_fh = ocfs2_encode_fh, 245 246 .get_parent = ocfs2_get_parent, 247 .get_dentry = ocfs2_get_dentry, 248 }; 249