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.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2014, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
35 #include <linux/stat.h>
36 #include <linux/version.h>
37 #define DEBUG_SUBSYSTEM S_LLITE
39 #include "llite_internal.h"
41 static int ll_readlink_internal(struct inode *inode,
42 struct ptlrpc_request **request, char **symname)
44 struct ll_inode_info *lli = ll_i2info(inode);
45 struct ll_sb_info *sbi = ll_i2sbi(inode);
46 int rc, symlen = i_size_read(inode) + 1;
47 struct mdt_body *body;
48 struct md_op_data *op_data;
54 if (lli->lli_symlink_name) {
55 int print_limit = min_t(int, PAGE_SIZE - 128, symlen);
57 *symname = lli->lli_symlink_name;
59 * If the total CDEBUG() size is larger than a page, it
60 * will print a warning to the console, avoid this by
61 * printing just the last part of the symlink.
63 CDEBUG(D_INODE, "using cached symlink %s%.*s, len = %d\n",
64 print_limit < symlen ? "..." : "", print_limit,
65 (*symname) + symlen - print_limit, symlen);
69 op_data = ll_prep_md_op_data(NULL, inode, NULL, NULL, 0, symlen,
70 LUSTRE_OPC_ANY, NULL);
72 RETURN(PTR_ERR(op_data));
74 op_data->op_valid = OBD_MD_LINKNAME;
75 rc = md_getattr(sbi->ll_md_exp, op_data, request);
76 ll_finish_md_op_data(op_data);
79 CERROR("%s: inode "DFID": rc = %d\n",
80 ll_get_fsname(inode->i_sb, NULL, 0),
81 PFID(ll_inode2fid(inode)), rc);
85 body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
86 LASSERT(body != NULL);
87 if ((body->mbo_valid & OBD_MD_LINKNAME) == 0) {
88 CERROR("OBD_MD_LINKNAME not set on reply\n");
89 GOTO(failed, rc = -EPROTO);
93 if (body->mbo_eadatasize != symlen) {
94 CERROR("%s: inode "DFID": symlink length %d not expected %d\n",
95 ll_get_fsname(inode->i_sb, NULL, 0),
96 PFID(ll_inode2fid(inode)), body->mbo_eadatasize - 1,
98 GOTO(failed, rc = -EPROTO);
101 *symname = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_MD);
102 if (!*symname || strnlen(*symname, symlen) != symlen - 1) {
103 /* not full/NULL terminated */
104 CERROR("%s: inode "DFID": symlink not NULL terminated string"
105 "of length %d\n", ll_get_fsname(inode->i_sb, NULL, 0),
106 PFID(ll_inode2fid(inode)), symlen - 1);
107 GOTO(failed, rc = -EPROTO);
110 OBD_ALLOC(lli->lli_symlink_name, symlen);
111 /* do not return an error if we cannot cache the symlink locally */
112 if (lli->lli_symlink_name) {
113 memcpy(lli->lli_symlink_name, *symname, symlen);
114 *symname = lli->lli_symlink_name;
122 #ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
123 static void ll_put_link(struct dentry *dentry,
124 struct nameidata *nd, void *cookie)
126 # ifdef HAVE_IOP_GET_LINK
127 static void ll_put_link(void *cookie)
129 static void ll_put_link(struct inode *unused, void *cookie)
133 ptlrpc_req_finished(cookie);
136 #ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
137 static void *ll_follow_link(struct dentry *dentry, struct nameidata *nd)
139 struct inode *inode = dentry->d_inode;
140 struct ptlrpc_request *request = NULL;
142 char *symname = NULL;
146 CDEBUG(D_VFSTRACE, "VFS Op\n");
148 * Limit the recursive symlink depth to 5 instead of default
149 * 8 links when kernel has 4k stack to prevent stack overflow.
150 * For 8k stacks we need to limit it to 7 for local servers.
152 if (THREAD_SIZE < 8192 && current->link_count >= 6) {
154 } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
157 ll_inode_size_lock(inode);
158 rc = ll_readlink_internal(inode, &request, &symname);
159 ll_inode_size_unlock(inode);
162 ptlrpc_req_finished(request);
164 symname = ERR_PTR(rc);
167 nd_set_link(nd, symname);
169 * symname may contain a pointer to the request message buffer,
170 * we delay request releasing until ll_put_link then.
175 # ifdef HAVE_IOP_GET_LINK
176 static const char *ll_get_link(struct dentry *dentry,
178 struct delayed_call *done)
180 struct ptlrpc_request *request;
181 char *symname = NULL;
185 CDEBUG(D_VFSTRACE, "VFS Op\n");
187 RETURN(ERR_PTR(-ECHILD));
188 ll_inode_size_lock(inode);
189 rc = ll_readlink_internal(inode, &request, &symname);
190 ll_inode_size_unlock(inode);
192 ptlrpc_req_finished(request);
197 * symname may contain a pointer to the request message buffer,
198 * we delay request releasing then.
200 set_delayed_call(done, ll_put_link, request);
204 static const char *ll_follow_link(struct dentry *dentry, void **cookie)
206 struct inode *inode = d_inode(dentry);
207 struct ptlrpc_request *request;
208 char *symname = NULL;
213 CDEBUG(D_VFSTRACE, "VFS Op\n");
214 ll_inode_size_lock(inode);
215 rc = ll_readlink_internal(inode, &request, &symname);
216 ll_inode_size_unlock(inode);
218 ptlrpc_req_finished(request);
223 * symname may contain a pointer to the request message buffer,
224 * we delay request releasing until ll_put_link then.
229 # endif /* HAVE_IOP_GET_LINK */
230 #endif /* HAVE_SYMLINK_OPS_USE_NAMEIDATA */
232 struct inode_operations ll_fast_symlink_inode_operations = {
233 #ifdef HAVE_IOP_GENERIC_READLINK
234 .readlink = generic_readlink,
236 .setattr = ll_setattr,
237 #ifdef HAVE_IOP_GET_LINK
238 .get_link = ll_get_link,
240 .follow_link = ll_follow_link,
241 .put_link = ll_put_link,
243 .getattr = ll_getattr,
244 .permission = ll_inode_permission,
245 #ifdef HAVE_IOP_XATTR
246 .setxattr = ll_setxattr,
247 .getxattr = ll_getxattr,
248 .removexattr = ll_removexattr,
250 .listxattr = ll_listxattr,