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);
53 struct mds_body *body;
54 int rc, symlen = i_size_read(inode) + 1;
59 if (lli->lli_symlink_name) {
60 *symname = lli->lli_symlink_name;
61 CDEBUG(D_INODE, "using cached symlink %s\n", *symname);
65 ll_inode2fid(&fid, inode);
66 rc = mdc_getattr(sbi->ll_mdc_exp, &fid,
67 OBD_MD_LINKNAME, symlen, request);
70 CERROR("inode %lu: rc = %d\n", inode->i_ino, rc);
74 body = lustre_msg_buf((*request)->rq_repmsg, REPLY_REC_OFF,
76 LASSERT(body != NULL);
77 LASSERT(lustre_rep_swabbed(*request, REPLY_REC_OFF));
79 if ((body->valid & OBD_MD_LINKNAME) == 0) {
80 CERROR("OBD_MD_LINKNAME not set on reply\n");
81 GOTO(failed, rc = -EPROTO);
85 if (body->eadatasize != symlen) {
86 CERROR("inode %lu: symlink length %d not expected %d\n",
87 inode->i_ino, body->eadatasize - 1, symlen - 1);
88 GOTO(failed, rc = -EPROTO);
91 *symname = lustre_msg_buf((*request)->rq_repmsg, REPLY_REC_OFF + 1,
93 if (*symname == NULL ||
94 strnlen (*symname, symlen) != symlen - 1) {
95 /* not full/NULL terminated */
96 CERROR("inode %lu: symlink not NULL terminated string"
97 "of length %d\n", inode->i_ino, symlen - 1);
98 GOTO(failed, rc = -EPROTO);
101 OBD_ALLOC(lli->lli_symlink_name, symlen);
102 /* do not return an error if we cannot cache the symlink locally */
103 if (lli->lli_symlink_name) {
104 memcpy(lli->lli_symlink_name, *symname, symlen);
105 *symname = lli->lli_symlink_name;
113 static int ll_readlink(struct dentry *dentry, char *buffer, int buflen)
115 struct inode *inode = dentry->d_inode;
116 struct ll_inode_info *lli = ll_i2info(inode);
117 struct ptlrpc_request *request;
122 CDEBUG(D_VFSTRACE, "VFS Op\n");
123 /* on symlinks lli_open_sem protects lli_symlink_name allocation/data */
124 down(&lli->lli_size_sem);
125 rc = ll_readlink_internal(inode, &request, &symname);
129 rc = vfs_readlink(dentry, buffer, buflen, symname);
131 ptlrpc_req_finished(request);
132 up(&lli->lli_size_sem);
136 #ifdef HAVE_COOKIE_FOLLOW_LINK
137 # define LL_FOLLOW_LINK_RETURN_TYPE void *
139 # define LL_FOLLOW_LINK_RETURN_TYPE int
142 static LL_FOLLOW_LINK_RETURN_TYPE ll_follow_link(struct dentry *dentry, struct nameidata *nd)
144 struct inode *inode = dentry->d_inode;
145 struct ll_inode_info *lli = ll_i2info(inode);
146 #ifdef HAVE_VFS_INTENT_PATCHES
147 struct lookup_intent *it = ll_nd2it(nd);
149 struct ptlrpc_request *request = NULL;
154 #ifdef HAVE_VFS_INTENT_PATCHES
157 int mode = it->it_create_mode;
159 ll_intent_release(it);
161 it->it_create_mode = mode;
165 CDEBUG(D_VFSTRACE, "VFS Op\n");
166 /* Limit the recursive symlink depth to 5 instead of default
167 * 8 links when kernel has 4k stack to prevent stack overflow.
168 * For 8k stacks we need to limit it to 7 for local servers. */
169 if (THREAD_SIZE < 8192 && current->link_count >= 6) {
171 } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
174 down(&lli->lli_size_sem);
175 rc = ll_readlink_internal(inode, &request, &symname);
176 up(&lli->lli_size_sem);
179 cfs_path_put(nd); /* Kernel assumes that ->follow_link()
180 releases nameidata on error */
184 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,8))
185 rc = vfs_follow_link(nd, symname);
187 # ifdef HAVE_COOKIE_FOLLOW_LINK
188 nd_set_link(nd, symname);
189 /* @symname may contain a pointer to the request message buffer,
190 we delay request releasing until ll_put_link then. */
193 if (lli->lli_symlink_name == NULL) {
194 /* falling back to recursive follow link if the request
195 * needs to be cleaned up still. */
196 rc = vfs_follow_link(nd, symname);
199 nd_set_link(nd, symname);
204 ptlrpc_req_finished(request);
205 #ifdef HAVE_COOKIE_FOLLOW_LINK
212 #ifdef HAVE_COOKIE_FOLLOW_LINK
213 static void ll_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
215 ptlrpc_req_finished(cookie);
219 struct inode_operations ll_fast_symlink_inode_operations = {
220 .readlink = ll_readlink,
221 .setattr = ll_setattr,
222 #ifdef HAVE_VFS_INTENT_PATCHES
223 .setattr_raw = ll_setattr_raw,
225 .follow_link = ll_follow_link,
226 #ifdef HAVE_COOKIE_FOLLOW_LINK
227 .put_link = ll_put_link,
229 .getattr = ll_getattr,
230 .permission = ll_inode_permission,
231 .setxattr = ll_setxattr,
232 .getxattr = ll_getxattr,
233 .listxattr = ll_listxattr,
234 .removexattr = ll_removexattr,