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 #include <linux/namei.h> 43 44 #define MLOG_MASK_PREFIX ML_NAMEI 45 #include <cluster/masklog.h> 46 47 #include "ocfs2.h" 48 49 #include "alloc.h" 50 #include "file.h" 51 #include "inode.h" 52 #include "journal.h" 53 #include "symlink.h" 54 #include "xattr.h" 55 56 #include "buffer_head_io.h" 57 58 59 static char *ocfs2_fast_symlink_getlink(struct inode *inode, 60 struct buffer_head **bh) 61 { 62 int status; 63 char *link = NULL; 64 struct ocfs2_dinode *fe; 65 66 mlog_entry_void(); 67 68 status = ocfs2_read_inode_block(inode, bh); 69 if (status < 0) { 70 mlog_errno(status); 71 link = ERR_PTR(status); 72 goto bail; 73 } 74 75 fe = (struct ocfs2_dinode *) (*bh)->b_data; 76 link = (char *) fe->id2.i_symlink; 77 bail: 78 mlog_exit(status); 79 80 return link; 81 } 82 83 static int ocfs2_readlink(struct dentry *dentry, 84 char __user *buffer, 85 int buflen) 86 { 87 int ret; 88 char *link; 89 struct buffer_head *bh = NULL; 90 struct inode *inode = dentry->d_inode; 91 92 mlog_entry_void(); 93 94 link = ocfs2_fast_symlink_getlink(inode, &bh); 95 if (IS_ERR(link)) { 96 ret = PTR_ERR(link); 97 goto out; 98 } 99 100 /* 101 * Without vfsmount we can't update atime now, 102 * but we will update atime here ultimately. 103 */ 104 ret = vfs_readlink(dentry, buffer, buflen, link); 105 106 brelse(bh); 107 out: 108 mlog_exit(ret); 109 return ret; 110 } 111 112 static void *ocfs2_fast_follow_link(struct dentry *dentry, 113 struct nameidata *nd) 114 { 115 int status = 0; 116 int len; 117 char *target, *link = ERR_PTR(-ENOMEM); 118 struct inode *inode = dentry->d_inode; 119 struct buffer_head *bh = NULL; 120 121 mlog_entry_void(); 122 123 BUG_ON(!ocfs2_inode_is_fast_symlink(inode)); 124 target = ocfs2_fast_symlink_getlink(inode, &bh); 125 if (IS_ERR(target)) { 126 status = PTR_ERR(target); 127 mlog_errno(status); 128 goto bail; 129 } 130 131 /* Fast symlinks can't be large */ 132 len = strlen(target); 133 link = kzalloc(len + 1, GFP_NOFS); 134 if (!link) { 135 status = -ENOMEM; 136 mlog_errno(status); 137 goto bail; 138 } 139 140 memcpy(link, target, len); 141 nd_set_link(nd, link); 142 143 bail: 144 brelse(bh); 145 146 mlog_exit(status); 147 return status ? ERR_PTR(status) : link; 148 } 149 150 static void ocfs2_fast_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) 151 { 152 char *link = cookie; 153 154 kfree(link); 155 } 156 157 const struct inode_operations ocfs2_symlink_inode_operations = { 158 .readlink = page_readlink, 159 .follow_link = page_follow_link_light, 160 .put_link = page_put_link, 161 .getattr = ocfs2_getattr, 162 .setattr = ocfs2_setattr, 163 .setxattr = generic_setxattr, 164 .getxattr = generic_getxattr, 165 .listxattr = ocfs2_listxattr, 166 .removexattr = generic_removexattr, 167 }; 168 const struct inode_operations ocfs2_fast_symlink_inode_operations = { 169 .readlink = ocfs2_readlink, 170 .follow_link = ocfs2_fast_follow_link, 171 .put_link = ocfs2_fast_put_link, 172 .getattr = ocfs2_getattr, 173 .setattr = ocfs2_setattr, 174 .setxattr = generic_setxattr, 175 .getxattr = generic_getxattr, 176 .listxattr = ocfs2_listxattr, 177 .removexattr = generic_removexattr, 178 }; 179