1 /* -*- mode: c; c-basic-offset: 8; -*- 2 * vim: noexpandtab sw=8 ts=8 sts=0: 3 * 4 * linux/cluster/ssi/cfs/symlink.c 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE 14 * or NON INFRINGEMENT. See the GNU General Public License for more 15 * details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 20 * 21 * Questions/Comments/Bugfixes to ssic-linux-devel@lists.sourceforge.net 22 * 23 * Copyright (C) 1992 Rick Sladkey 24 * 25 * Optimization changes Copyright (C) 1994 Florian La Roche 26 * 27 * Jun 7 1999, cache symlink lookups in the page cache. -DaveM 28 * 29 * Portions Copyright (C) 2001 Compaq Computer Corporation 30 * 31 * ocfs2 symlink handling code. 32 * 33 * Copyright (C) 2004, 2005 Oracle. 34 * 35 */ 36 37 #include <linux/fs.h> 38 #include <linux/types.h> 39 #include <linux/slab.h> 40 #include <linux/pagemap.h> 41 #include <linux/utsname.h> 42 43 #define MLOG_MASK_PREFIX ML_NAMEI 44 #include <cluster/masklog.h> 45 46 #include "ocfs2.h" 47 48 #include "alloc.h" 49 #include "file.h" 50 #include "inode.h" 51 #include "journal.h" 52 #include "symlink.h" 53 #include "xattr.h" 54 55 #include "buffer_head_io.h" 56 57 static char *ocfs2_page_getlink(struct dentry * dentry, 58 struct page **ppage); 59 static char *ocfs2_fast_symlink_getlink(struct inode *inode, 60 struct buffer_head **bh); 61 62 /* get the link contents into pagecache */ 63 static char *ocfs2_page_getlink(struct dentry * dentry, 64 struct page **ppage) 65 { 66 struct page * page; 67 struct address_space *mapping = dentry->d_inode->i_mapping; 68 page = read_mapping_page(mapping, 0, NULL); 69 if (IS_ERR(page)) 70 goto sync_fail; 71 *ppage = page; 72 return kmap(page); 73 74 sync_fail: 75 return (char*)page; 76 } 77 78 static char *ocfs2_fast_symlink_getlink(struct inode *inode, 79 struct buffer_head **bh) 80 { 81 int status; 82 char *link = NULL; 83 struct ocfs2_dinode *fe; 84 85 mlog_entry_void(); 86 87 status = ocfs2_read_block(inode, OCFS2_I(inode)->ip_blkno, bh); 88 if (status < 0) { 89 mlog_errno(status); 90 link = ERR_PTR(status); 91 goto bail; 92 } 93 94 fe = (struct ocfs2_dinode *) (*bh)->b_data; 95 link = (char *) fe->id2.i_symlink; 96 bail: 97 mlog_exit(status); 98 99 return link; 100 } 101 102 static int ocfs2_readlink(struct dentry *dentry, 103 char __user *buffer, 104 int buflen) 105 { 106 int ret; 107 char *link; 108 struct buffer_head *bh = NULL; 109 struct inode *inode = dentry->d_inode; 110 111 mlog_entry_void(); 112 113 link = ocfs2_fast_symlink_getlink(inode, &bh); 114 if (IS_ERR(link)) { 115 ret = PTR_ERR(link); 116 goto out; 117 } 118 119 /* 120 * Without vfsmount we can't update atime now, 121 * but we will update atime here ultimately. 122 */ 123 ret = vfs_readlink(dentry, buffer, buflen, link); 124 125 brelse(bh); 126 out: 127 mlog_exit(ret); 128 return ret; 129 } 130 131 static void *ocfs2_follow_link(struct dentry *dentry, 132 struct nameidata *nd) 133 { 134 int status; 135 char *link; 136 struct inode *inode = dentry->d_inode; 137 struct page *page = NULL; 138 struct buffer_head *bh = NULL; 139 140 if (ocfs2_inode_is_fast_symlink(inode)) 141 link = ocfs2_fast_symlink_getlink(inode, &bh); 142 else 143 link = ocfs2_page_getlink(dentry, &page); 144 if (IS_ERR(link)) { 145 status = PTR_ERR(link); 146 mlog_errno(status); 147 goto bail; 148 } 149 150 status = vfs_follow_link(nd, link); 151 152 bail: 153 if (page) { 154 kunmap(page); 155 page_cache_release(page); 156 } 157 brelse(bh); 158 159 return ERR_PTR(status); 160 } 161 162 const struct inode_operations ocfs2_symlink_inode_operations = { 163 .readlink = page_readlink, 164 .follow_link = ocfs2_follow_link, 165 .getattr = ocfs2_getattr, 166 .setattr = ocfs2_setattr, 167 .setxattr = generic_setxattr, 168 .getxattr = generic_getxattr, 169 .listxattr = ocfs2_listxattr, 170 .removexattr = generic_removexattr, 171 }; 172 const struct inode_operations ocfs2_fast_symlink_inode_operations = { 173 .readlink = ocfs2_readlink, 174 .follow_link = ocfs2_follow_link, 175 .getattr = ocfs2_getattr, 176 .setattr = ocfs2_setattr, 177 .setxattr = generic_setxattr, 178 .getxattr = generic_getxattr, 179 .listxattr = ocfs2_listxattr, 180 .removexattr = generic_removexattr, 181 }; 182