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