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, 49 struct ocfs2_inode_handle *handle) 50 { 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, 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_obtain_alias(inode); 72 if (!IS_ERR(result)) 73 result->d_op = &ocfs2_dentry_ops; 74 75 mlog_exit_ptr(result); 76 return result; 77 } 78 79 static struct dentry *ocfs2_get_parent(struct dentry *child) 80 { 81 int status; 82 u64 blkno; 83 struct dentry *parent; 84 struct inode *dir = child->d_inode; 85 86 mlog_entry("(0x%p, '%.*s')\n", child, 87 child->d_name.len, child->d_name.name); 88 89 mlog(0, "find parent of directory %llu\n", 90 (unsigned long long)OCFS2_I(dir)->ip_blkno); 91 92 status = ocfs2_inode_lock(dir, NULL, 0); 93 if (status < 0) { 94 if (status != -ENOENT) 95 mlog_errno(status); 96 parent = ERR_PTR(status); 97 goto bail; 98 } 99 100 status = ocfs2_lookup_ino_from_name(dir, "..", 2, &blkno); 101 if (status < 0) { 102 parent = ERR_PTR(-ENOENT); 103 goto bail_unlock; 104 } 105 106 parent = d_obtain_alias(ocfs2_iget(OCFS2_SB(dir->i_sb), blkno, 0, 0)); 107 if (!IS_ERR(parent)) 108 parent->d_op = &ocfs2_dentry_ops; 109 110 bail_unlock: 111 ocfs2_inode_unlock(dir, 0); 112 113 bail: 114 mlog_exit_ptr(parent); 115 116 return parent; 117 } 118 119 static int ocfs2_encode_fh(struct dentry *dentry, u32 *fh_in, int *max_len, 120 int connectable) 121 { 122 struct inode *inode = dentry->d_inode; 123 int len = *max_len; 124 int type = 1; 125 u64 blkno; 126 u32 generation; 127 __le32 *fh = (__force __le32 *) fh_in; 128 129 mlog_entry("(0x%p, '%.*s', 0x%p, %d, %d)\n", dentry, 130 dentry->d_name.len, dentry->d_name.name, 131 fh, len, connectable); 132 133 if (len < 3 || (connectable && len < 6)) { 134 mlog(ML_ERROR, "fh buffer is too small for encoding\n"); 135 type = 255; 136 goto bail; 137 } 138 139 blkno = OCFS2_I(inode)->ip_blkno; 140 generation = inode->i_generation; 141 142 mlog(0, "Encoding fh: blkno: %llu, generation: %u\n", 143 (unsigned long long)blkno, generation); 144 145 len = 3; 146 fh[0] = cpu_to_le32((u32)(blkno >> 32)); 147 fh[1] = cpu_to_le32((u32)(blkno & 0xffffffff)); 148 fh[2] = cpu_to_le32(generation); 149 150 if (connectable && !S_ISDIR(inode->i_mode)) { 151 struct inode *parent; 152 153 spin_lock(&dentry->d_lock); 154 155 parent = dentry->d_parent->d_inode; 156 blkno = OCFS2_I(parent)->ip_blkno; 157 generation = parent->i_generation; 158 159 fh[3] = cpu_to_le32((u32)(blkno >> 32)); 160 fh[4] = cpu_to_le32((u32)(blkno & 0xffffffff)); 161 fh[5] = cpu_to_le32(generation); 162 163 spin_unlock(&dentry->d_lock); 164 165 len = 6; 166 type = 2; 167 168 mlog(0, "Encoding parent: blkno: %llu, generation: %u\n", 169 (unsigned long long)blkno, generation); 170 } 171 172 *max_len = len; 173 174 bail: 175 mlog_exit(type); 176 return type; 177 } 178 179 static struct dentry *ocfs2_fh_to_dentry(struct super_block *sb, 180 struct fid *fid, int fh_len, int fh_type) 181 { 182 struct ocfs2_inode_handle handle; 183 184 if (fh_len < 3 || fh_type > 2) 185 return NULL; 186 187 handle.ih_blkno = (u64)le32_to_cpu(fid->raw[0]) << 32; 188 handle.ih_blkno |= (u64)le32_to_cpu(fid->raw[1]); 189 handle.ih_generation = le32_to_cpu(fid->raw[2]); 190 return ocfs2_get_dentry(sb, &handle); 191 } 192 193 static struct dentry *ocfs2_fh_to_parent(struct super_block *sb, 194 struct fid *fid, int fh_len, int fh_type) 195 { 196 struct ocfs2_inode_handle parent; 197 198 if (fh_type != 2 || fh_len < 6) 199 return NULL; 200 201 parent.ih_blkno = (u64)le32_to_cpu(fid->raw[3]) << 32; 202 parent.ih_blkno |= (u64)le32_to_cpu(fid->raw[4]); 203 parent.ih_generation = le32_to_cpu(fid->raw[5]); 204 return ocfs2_get_dentry(sb, &parent); 205 } 206 207 const struct export_operations ocfs2_export_ops = { 208 .encode_fh = ocfs2_encode_fh, 209 .fh_to_dentry = ocfs2_fh_to_dentry, 210 .fh_to_parent = ocfs2_fh_to_parent, 211 .get_parent = ocfs2_get_parent, 212 }; 213