4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
27 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2011, Whamcloud, Inc.
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;
54 struct md_op_data *op_data;
59 if (lli->lli_symlink_name) {
60 int print_limit = min_t(int, PAGE_SIZE - 128, symlen);
62 *symname = lli->lli_symlink_name;
63 /* If the total CDEBUG() size is larger than a page, it
64 * will print a warning to the console, avoid this by
65 * printing just the last part of the symlink. */
66 CDEBUG(D_INODE, "using cached symlink %s%.*s, len = %d\n",
67 print_limit < symlen ? "..." : "", print_limit,
68 (*symname) + symlen - print_limit, symlen);
72 op_data = ll_prep_md_op_data(NULL, inode, NULL, NULL, 0, symlen,
73 LUSTRE_OPC_ANY, NULL);
75 RETURN(PTR_ERR(op_data));
77 op_data->op_valid = OBD_MD_LINKNAME;
78 rc = md_getattr(sbi->ll_md_exp, op_data, request);
79 ll_finish_md_op_data(op_data);
82 CERROR("inode %lu: rc = %d\n", inode->i_ino, rc);
86 body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
87 LASSERT(body != NULL);
88 if ((body->valid & OBD_MD_LINKNAME) == 0) {
89 CERROR("OBD_MD_LINKNAME not set on reply\n");
90 GOTO(failed, rc = -EPROTO);
94 if (body->eadatasize != symlen) {
95 CERROR("inode %lu: symlink length %d not expected %d\n",
96 inode->i_ino, body->eadatasize - 1, symlen - 1);
97 GOTO(failed, rc = -EPROTO);
100 *symname = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_MD);
101 if (*symname == NULL ||
102 strnlen(*symname, symlen) != symlen - 1) {
103 /* not full/NULL terminated */
104 CERROR("inode %lu: symlink not NULL terminated string"
105 "of length %d\n", inode->i_ino, symlen - 1);
106 GOTO(failed, rc = -EPROTO);
109 OBD_ALLOC(lli->lli_symlink_name, symlen);
110 /* do not return an error if we cannot cache the symlink locally */
111 if (lli->lli_symlink_name) {
112 memcpy(lli->lli_symlink_name, *symname, symlen);
113 *symname = lli->lli_symlink_name;
121 static int ll_readlink(struct dentry *dentry, char *buffer, int buflen)
123 struct inode *inode = dentry->d_inode;
124 struct ptlrpc_request *request;
129 CDEBUG(D_VFSTRACE, "VFS Op\n");
131 ll_inode_size_lock(inode);
132 rc = ll_readlink_internal(inode, &request, &symname);
136 rc = vfs_readlink(dentry, buffer, buflen, symname);
138 ptlrpc_req_finished(request);
139 ll_inode_size_unlock(inode);
143 #ifdef HAVE_COOKIE_FOLLOW_LINK
144 # define LL_FOLLOW_LINK_RETURN_TYPE void *
146 # define LL_FOLLOW_LINK_RETURN_TYPE int
149 static LL_FOLLOW_LINK_RETURN_TYPE ll_follow_link(struct dentry *dentry,
150 struct nameidata *nd)
152 struct inode *inode = dentry->d_inode;
153 struct ptlrpc_request *request = NULL;
158 CDEBUG(D_VFSTRACE, "VFS Op\n");
159 /* Limit the recursive symlink depth to 5 instead of default
160 * 8 links when kernel has 4k stack to prevent stack overflow.
161 * For 8k stacks we need to limit it to 7 for local servers. */
162 if (THREAD_SIZE < 8192 && current->link_count >= 6) {
164 } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
167 ll_inode_size_lock(inode);
168 rc = ll_readlink_internal(inode, &request, &symname);
169 ll_inode_size_unlock(inode);
172 cfs_path_put(nd); /* Kernel assumes that ->follow_link()
173 releases nameidata on error */
177 #ifdef HAVE_COOKIE_FOLLOW_LINK
178 nd_set_link(nd, symname);
179 /* @symname may contain a pointer to the request message buffer,
180 we delay request releasing until ll_put_link then. */
183 if (lli->lli_symlink_name == NULL) {
184 /* falling back to recursive follow link if the request
185 * needs to be cleaned up still. */
186 rc = vfs_follow_link(nd, symname);
189 nd_set_link(nd, symname);
193 ptlrpc_req_finished(request);
194 #ifdef HAVE_COOKIE_FOLLOW_LINK
201 #ifdef HAVE_COOKIE_FOLLOW_LINK
202 static void ll_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
204 ptlrpc_req_finished(cookie);
208 struct inode_operations ll_fast_symlink_inode_operations = {
209 .readlink = ll_readlink,
210 .setattr = ll_setattr,
211 .follow_link = ll_follow_link,
212 #ifdef HAVE_COOKIE_FOLLOW_LINK
213 .put_link = ll_put_link,
215 .getattr = ll_getattr,
216 .permission = ll_inode_permission,
217 .setxattr = ll_setxattr,
218 .getxattr = ll_getxattr,
219 .listxattr = ll_listxattr,
220 .removexattr = ll_removexattr,