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;
53 if (lli->lli_symlink_name) {
54 int print_limit = min_t(int, PAGE_SIZE - 128, symlen);
56 *symname = lli->lli_symlink_name;
57 /* If the total CDEBUG() size is larger than a page, it
58 * will print a warning to the console, avoid this by
59 * printing just the last part of the symlink. */
60 CDEBUG(D_INODE, "using cached symlink %s%.*s, len = %d\n",
61 print_limit < symlen ? "..." : "", print_limit,
62 (*symname) + symlen - print_limit, symlen);
66 op_data = ll_prep_md_op_data(NULL, inode, NULL, NULL, 0, symlen,
67 LUSTRE_OPC_ANY, NULL);
69 RETURN(PTR_ERR(op_data));
71 op_data->op_valid = OBD_MD_LINKNAME;
72 rc = md_getattr(sbi->ll_md_exp, op_data, request);
73 ll_finish_md_op_data(op_data);
76 CERROR("%s: inode "DFID": rc = %d\n",
77 ll_get_fsname(inode->i_sb, NULL, 0),
78 PFID(ll_inode2fid(inode)), rc);
82 body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
83 LASSERT(body != NULL);
84 if ((body->mbo_valid & OBD_MD_LINKNAME) == 0) {
85 CERROR("OBD_MD_LINKNAME not set on reply\n");
86 GOTO(failed, rc = -EPROTO);
90 if (body->mbo_eadatasize != symlen) {
91 CERROR("%s: inode "DFID": symlink length %d not expected %d\n",
92 ll_get_fsname(inode->i_sb, NULL, 0),
93 PFID(ll_inode2fid(inode)), body->mbo_eadatasize - 1,
95 GOTO(failed, rc = -EPROTO);
98 *symname = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_MD);
99 if (*symname == NULL ||
100 strnlen(*symname, symlen) != symlen - 1) {
101 /* not full/NULL terminated */
102 CERROR("%s: inode "DFID": symlink not NULL terminated string"
103 "of length %d\n", ll_get_fsname(inode->i_sb, NULL, 0),
104 PFID(ll_inode2fid(inode)), symlen - 1);
105 GOTO(failed, rc = -EPROTO);
108 OBD_ALLOC(lli->lli_symlink_name, symlen);
109 /* do not return an error if we cannot cache the symlink locally */
110 if (lli->lli_symlink_name) {
111 memcpy(lli->lli_symlink_name, *symname, symlen);
112 *symname = lli->lli_symlink_name;
120 #ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
121 static void ll_put_link(struct dentry *dentry,
122 struct nameidata *nd, void *cookie)
124 # ifdef HAVE_IOP_GET_LINK
125 static void ll_put_link(void *cookie)
127 static void ll_put_link(struct inode *unused, void *cookie)
131 ptlrpc_req_finished(cookie);
134 #ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
135 static void *ll_follow_link(struct dentry *dentry, struct nameidata *nd)
137 struct inode *inode = dentry->d_inode;
138 struct ptlrpc_request *request = NULL;
140 char *symname = NULL;
143 CDEBUG(D_VFSTRACE, "VFS Op\n");
144 /* Limit the recursive symlink depth to 5 instead of default
145 * 8 links when kernel has 4k stack to prevent stack overflow.
146 * For 8k stacks we need to limit it to 7 for local servers. */
147 if (THREAD_SIZE < 8192 && current->link_count >= 6) {
149 } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
152 ll_inode_size_lock(inode);
153 rc = ll_readlink_internal(inode, &request, &symname);
154 ll_inode_size_unlock(inode);
157 ptlrpc_req_finished(request);
159 symname = ERR_PTR(rc);
162 nd_set_link(nd, symname);
163 /* symname may contain a pointer to the request message buffer,
164 * we delay request releasing until ll_put_link then.
169 # ifdef HAVE_IOP_GET_LINK
170 static const char *ll_get_link(struct dentry *dentry,
172 struct delayed_call *done)
174 struct ptlrpc_request *request;
175 char *symname = NULL;
179 CDEBUG(D_VFSTRACE, "VFS Op\n");
181 RETURN(ERR_PTR(-ECHILD));
182 ll_inode_size_lock(inode);
183 rc = ll_readlink_internal(inode, &request, &symname);
184 ll_inode_size_unlock(inode);
186 ptlrpc_req_finished(request);
190 /* symname may contain a pointer to the request message buffer,
191 * we delay request releasing then.
193 set_delayed_call(done, ll_put_link, request);
197 static const char *ll_follow_link(struct dentry *dentry, void **cookie)
199 struct inode *inode = d_inode(dentry);
200 struct ptlrpc_request *request;
201 char *symname = NULL;
205 CDEBUG(D_VFSTRACE, "VFS Op\n");
206 ll_inode_size_lock(inode);
207 rc = ll_readlink_internal(inode, &request, &symname);
208 ll_inode_size_unlock(inode);
210 ptlrpc_req_finished(request);
214 /* symname may contain a pointer to the request message buffer,
215 * we delay request releasing until ll_put_link then.
220 # endif /* HAVE_IOP_GET_LINK */
221 #endif /* HAVE_SYMLINK_OPS_USE_NAMEIDATA */
223 struct inode_operations ll_fast_symlink_inode_operations = {
224 #ifdef HAVE_IOP_GENERIC_READLINK
225 .readlink = generic_readlink,
227 .setattr = ll_setattr,
228 #ifdef HAVE_IOP_GET_LINK
229 .get_link = ll_get_link,
231 .follow_link = ll_follow_link,
232 .put_link = ll_put_link,
234 .getattr = ll_getattr,
235 .permission = ll_inode_permission,
236 #ifdef HAVE_IOP_XATTR
237 .setxattr = ll_setxattr,
238 .getxattr = ll_getxattr,
239 .removexattr = ll_removexattr,
241 .listxattr = ll_listxattr,