1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright 2008 Sun Microsystems, Inc. All rights reserved
30 * Use is subject to license terms.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
39 #include <linux/stat.h>
40 #include <linux/smp_lock.h>
41 #include <linux/version.h>
42 #define DEBUG_SUBSYSTEM S_LLITE
44 #include <lustre_lite.h>
45 #include "llite_internal.h"
47 static int ll_readlink_internal(struct inode *inode,
48 struct ptlrpc_request **request, char **symname)
50 struct ll_inode_info *lli = ll_i2info(inode);
51 struct ll_sb_info *sbi = ll_i2sbi(inode);
52 int rc, symlen = i_size_read(inode) + 1;
53 struct mdt_body *body;
59 if (lli->lli_symlink_name) {
60 *symname = lli->lli_symlink_name;
61 CDEBUG(D_INODE, "using cached symlink %s\n", *symname);
65 oc = ll_mdscapa_get(inode);
66 rc = md_getattr(sbi->ll_md_exp, ll_inode2fid(inode), oc,
67 OBD_MD_LINKNAME, symlen, request);
71 CERROR("inode %lu: rc = %d\n", inode->i_ino, rc);
75 body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
76 LASSERT(body != NULL);
77 if ((body->valid & OBD_MD_LINKNAME) == 0) {
78 CERROR("OBD_MD_LINKNAME not set on reply\n");
79 GOTO(failed, rc = -EPROTO);
83 if (body->eadatasize != symlen) {
84 CERROR("inode %lu: symlink length %d not expected %d\n",
85 inode->i_ino, body->eadatasize - 1, symlen - 1);
86 GOTO(failed, rc = -EPROTO);
89 *symname = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_MD);
90 if (*symname == NULL ||
91 strnlen(*symname, symlen) != symlen - 1) {
92 /* not full/NULL terminated */
93 CERROR("inode %lu: symlink not NULL terminated string"
94 "of length %d\n", inode->i_ino, symlen - 1);
95 GOTO(failed, rc = -EPROTO);
98 OBD_ALLOC(lli->lli_symlink_name, symlen);
99 /* do not return an error if we cannot cache the symlink locally */
100 if (lli->lli_symlink_name) {
101 memcpy(lli->lli_symlink_name, *symname, symlen);
102 *symname = lli->lli_symlink_name;
110 static int ll_readlink(struct dentry *dentry, char *buffer, int buflen)
112 struct inode *inode = dentry->d_inode;
113 struct ptlrpc_request *request;
118 CDEBUG(D_VFSTRACE, "VFS Op\n");
119 /* on symlinks lli_open_sem protects lli_symlink_name allocation/data */
120 ll_inode_size_lock(inode, 0);
121 rc = ll_readlink_internal(inode, &request, &symname);
125 rc = vfs_readlink(dentry, buffer, buflen, symname);
127 ptlrpc_req_finished(request);
128 ll_inode_size_unlock(inode, 0);
132 #ifdef HAVE_COOKIE_FOLLOW_LINK
133 # define LL_FOLLOW_LINK_RETURN_TYPE void *
135 # define LL_FOLLOW_LINK_RETURN_TYPE int
138 static LL_FOLLOW_LINK_RETURN_TYPE ll_follow_link(struct dentry *dentry,
139 struct nameidata *nd)
141 struct inode *inode = dentry->d_inode;
142 #ifdef HAVE_VFS_INTENT_PATCHES
143 struct lookup_intent *it = ll_nd2it(nd);
145 struct ptlrpc_request *request = NULL;
150 #ifdef HAVE_VFS_INTENT_PATCHES
153 int mode = it->it_create_mode;
155 ll_intent_release(it);
157 it->it_create_mode = mode;
161 CDEBUG(D_VFSTRACE, "VFS Op\n");
162 /* Limit the recursive symlink depth to 5 instead of default
163 * 8 links when kernel has 4k stack to prevent stack overflow.
164 * For 8k stacks we need to limit it to 7 for local servers. */
165 if (THREAD_SIZE < 8192 && current->link_count >= 6) {
167 } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
170 ll_inode_size_lock(inode, 0);
171 rc = ll_readlink_internal(inode, &request, &symname);
172 ll_inode_size_unlock(inode, 0);
175 path_release(nd); /* Kernel assumes that ->follow_link()
176 releases nameidata on error */
180 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,8))
181 rc = vfs_follow_link(nd, symname);
183 #ifdef HAVE_COOKIE_FOLLOW_LINK
184 nd_set_link(nd, symname);
185 /* @symname may contain a pointer to the request message buffer,
186 we delay request releasing until ll_put_link then. */
189 if (lli->lli_symlink_name == NULL) {
190 /* falling back to recursive follow link if the request
191 * needs to be cleaned up still. */
192 rc = vfs_follow_link(nd, symname);
195 nd_set_link(nd, symname);
200 ptlrpc_req_finished(request);
201 #ifdef HAVE_COOKIE_FOLLOW_LINK
208 #ifdef HAVE_COOKIE_FOLLOW_LINK
209 static void ll_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
211 ptlrpc_req_finished(cookie);
215 struct inode_operations ll_fast_symlink_inode_operations = {
216 .readlink = ll_readlink,
217 .setattr = ll_setattr,
218 #ifdef HAVE_VFS_INTENT_PATCHES
219 .setattr_raw = ll_setattr_raw,
221 .follow_link = ll_follow_link,
222 #ifdef HAVE_COOKIE_FOLLOW_LINK
223 .put_link = ll_put_link,
225 .getattr = ll_getattr,
226 .permission = ll_inode_permission,
227 .setxattr = ll_setxattr,
228 .getxattr = ll_getxattr,
229 .listxattr = ll_listxattr,
230 .removexattr = ll_removexattr,