1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
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.
9 *
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).
15 *
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
19 *
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
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2011, 2012, Intel Corporation.
31 */
32 /*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 */
36
37 #include <linux/fs.h>
38 #include <linux/mm.h>
39 #include <linux/stat.h>
40 #define DEBUG_SUBSYSTEM S_LLITE
41
42 #include "../include/lustre_lite.h"
43 #include "llite_internal.h"
44
ll_readlink_internal(struct inode * inode,struct ptlrpc_request ** request,char ** symname)45 static int ll_readlink_internal(struct inode *inode,
46 struct ptlrpc_request **request, char **symname)
47 {
48 struct ll_inode_info *lli = ll_i2info(inode);
49 struct ll_sb_info *sbi = ll_i2sbi(inode);
50 int rc, symlen = i_size_read(inode) + 1;
51 struct mdt_body *body;
52 struct md_op_data *op_data;
53
54 *request = NULL;
55
56 if (lli->lli_symlink_name) {
57 int print_limit = min_t(int, PAGE_SIZE - 128, symlen);
58
59 *symname = lli->lli_symlink_name;
60 /* If the total CDEBUG() size is larger than a page, it
61 * will print a warning to the console, avoid this by
62 * 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);
66 return 0;
67 }
68
69 op_data = ll_prep_md_op_data(NULL, inode, NULL, NULL, 0, symlen,
70 LUSTRE_OPC_ANY, NULL);
71 if (IS_ERR(op_data))
72 return PTR_ERR(op_data);
73
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);
77 if (rc) {
78 if (rc != -ENOENT)
79 CERROR("inode %lu: rc = %d\n", inode->i_ino, rc);
80 goto failed;
81 }
82
83 body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
84 LASSERT(body != NULL);
85 if ((body->valid & OBD_MD_LINKNAME) == 0) {
86 CERROR("OBD_MD_LINKNAME not set on reply\n");
87 rc = -EPROTO;
88 goto failed;
89 }
90
91 LASSERT(symlen != 0);
92 if (body->eadatasize != symlen) {
93 CERROR("inode %lu: symlink length %d not expected %d\n",
94 inode->i_ino, body->eadatasize - 1, symlen - 1);
95 rc = -EPROTO;
96 goto failed;
97 }
98
99 *symname = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_MD);
100 if (*symname == NULL ||
101 strnlen(*symname, symlen) != symlen - 1) {
102 /* not full/NULL terminated */
103 CERROR("inode %lu: symlink not NULL terminated string of length %d\n",
104 inode->i_ino, symlen - 1);
105 rc = -EPROTO;
106 goto failed;
107 }
108
109 lli->lli_symlink_name = kzalloc(symlen, GFP_NOFS);
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;
114 }
115 return 0;
116
117 failed:
118 return rc;
119 }
120
ll_follow_link(struct dentry * dentry,void ** cookie)121 static const char *ll_follow_link(struct dentry *dentry, void **cookie)
122 {
123 struct inode *inode = d_inode(dentry);
124 struct ptlrpc_request *request = NULL;
125 int rc;
126 char *symname = NULL;
127
128 CDEBUG(D_VFSTRACE, "VFS Op\n");
129 ll_inode_size_lock(inode);
130 rc = ll_readlink_internal(inode, &request, &symname);
131 ll_inode_size_unlock(inode);
132 if (rc) {
133 ptlrpc_req_finished(request);
134 return ERR_PTR(rc);
135 }
136
137 /* symname may contain a pointer to the request message buffer,
138 * we delay request releasing until ll_put_link then.
139 */
140 *cookie = request;
141 return symname;
142 }
143
ll_put_link(struct inode * unused,void * cookie)144 static void ll_put_link(struct inode *unused, void *cookie)
145 {
146 ptlrpc_req_finished(cookie);
147 }
148
149 struct inode_operations ll_fast_symlink_inode_operations = {
150 .readlink = generic_readlink,
151 .setattr = ll_setattr,
152 .follow_link = ll_follow_link,
153 .put_link = ll_put_link,
154 .getattr = ll_getattr,
155 .permission = ll_inode_permission,
156 .setxattr = ll_setxattr,
157 .getxattr = ll_getxattr,
158 .listxattr = ll_listxattr,
159 .removexattr = ll_removexattr,
160 };
161