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 #include <cluster/masklog.h> 44 45 #include "ocfs2.h" 46 47 #include "alloc.h" 48 #include "file.h" 49 #include "inode.h" 50 #include "journal.h" 51 #include "symlink.h" 52 #include "xattr.h" 53 54 #include "buffer_head_io.h" 55 56 57 static char *ocfs2_fast_symlink_getlink(struct inode *inode, 58 struct buffer_head **bh) 59 { 60 int status; 61 char *link = NULL; 62 struct ocfs2_dinode *fe; 63 64 status = ocfs2_read_inode_block(inode, bh); 65 if (status < 0) { 66 mlog_errno(status); 67 link = ERR_PTR(status); 68 goto bail; 69 } 70 71 fe = (struct ocfs2_dinode *) (*bh)->b_data; 72 link = (char *) fe->id2.i_symlink; 73 bail: 74 75 return link; 76 } 77 78 static int ocfs2_readlink(struct dentry *dentry, 79 char __user *buffer, 80 int buflen) 81 { 82 int ret; 83 char *link; 84 struct buffer_head *bh = NULL; 85 struct inode *inode = dentry->d_inode; 86 87 link = ocfs2_fast_symlink_getlink(inode, &bh); 88 if (IS_ERR(link)) { 89 ret = PTR_ERR(link); 90 goto out; 91 } 92 93 /* 94 * Without vfsmount we can't update atime now, 95 * but we will update atime here ultimately. 96 */ 97 ret = vfs_readlink(dentry, buffer, buflen, link); 98 99 brelse(bh); 100 out: 101 if (ret < 0) 102 mlog_errno(ret); 103 return ret; 104 } 105 106 static void *ocfs2_fast_follow_link(struct dentry *dentry, 107 struct nameidata *nd) 108 { 109 int status = 0; 110 int len; 111 char *target, *link = ERR_PTR(-ENOMEM); 112 struct inode *inode = dentry->d_inode; 113 struct buffer_head *bh = NULL; 114 115 BUG_ON(!ocfs2_inode_is_fast_symlink(inode)); 116 target = ocfs2_fast_symlink_getlink(inode, &bh); 117 if (IS_ERR(target)) { 118 status = PTR_ERR(target); 119 mlog_errno(status); 120 goto bail; 121 } 122 123 /* Fast symlinks can't be large */ 124 len = strnlen(target, ocfs2_fast_symlink_chars(inode->i_sb)); 125 link = kzalloc(len + 1, GFP_NOFS); 126 if (!link) { 127 status = -ENOMEM; 128 mlog_errno(status); 129 goto bail; 130 } 131 132 memcpy(link, target, len); 133 134 bail: 135 nd_set_link(nd, status ? ERR_PTR(status) : link); 136 brelse(bh); 137 138 if (status) 139 mlog_errno(status); 140 return NULL; 141 } 142 143 static void ocfs2_fast_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) 144 { 145 char *link = nd_get_link(nd); 146 if (!IS_ERR(link)) 147 kfree(link); 148 } 149 150 const struct inode_operations ocfs2_symlink_inode_operations = { 151 .readlink = page_readlink, 152 .follow_link = page_follow_link_light, 153 .put_link = page_put_link, 154 .getattr = ocfs2_getattr, 155 .setattr = ocfs2_setattr, 156 .setxattr = generic_setxattr, 157 .getxattr = generic_getxattr, 158 .listxattr = ocfs2_listxattr, 159 .removexattr = generic_removexattr, 160 .fiemap = ocfs2_fiemap, 161 }; 162 const struct inode_operations ocfs2_fast_symlink_inode_operations = { 163 .readlink = ocfs2_readlink, 164 .follow_link = ocfs2_fast_follow_link, 165 .put_link = ocfs2_fast_put_link, 166 .getattr = ocfs2_getattr, 167 .setattr = ocfs2_setattr, 168 .setxattr = generic_setxattr, 169 .getxattr = generic_getxattr, 170 .listxattr = ocfs2_listxattr, 171 .removexattr = generic_removexattr, 172 .fiemap = ocfs2_fiemap, 173 }; 174