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,
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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
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18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
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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.
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30 * Copyright (c) 2011, 2014, Intel Corporation.
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/version.h>
41 #define DEBUG_SUBSYSTEM S_LLITE
43 #include "llite_internal.h"
45 static int ll_readlink_internal(struct inode *inode,
46 struct ptlrpc_request **request, char **symname)
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;
57 if (lli->lli_symlink_name) {
58 int print_limit = min_t(int, PAGE_SIZE - 128, symlen);
60 *symname = lli->lli_symlink_name;
61 /* If the total CDEBUG() size is larger than a page, it
62 * will print a warning to the console, avoid this by
63 * printing just the last part of the symlink. */
64 CDEBUG(D_INODE, "using cached symlink %s%.*s, len = %d\n",
65 print_limit < symlen ? "..." : "", print_limit,
66 (*symname) + symlen - print_limit, symlen);
70 op_data = ll_prep_md_op_data(NULL, inode, NULL, NULL, 0, symlen,
71 LUSTRE_OPC_ANY, NULL);
73 RETURN(PTR_ERR(op_data));
75 op_data->op_valid = OBD_MD_LINKNAME;
76 rc = md_getattr(sbi->ll_md_exp, op_data, request);
77 ll_finish_md_op_data(op_data);
80 CERROR("%s: inode "DFID": rc = %d\n",
81 ll_get_fsname(inode->i_sb, NULL, 0),
82 PFID(ll_inode2fid(inode)), rc);
86 body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
87 LASSERT(body != NULL);
88 if ((body->mbo_valid & OBD_MD_LINKNAME) == 0) {
89 CERROR("OBD_MD_LINKNAME not set on reply\n");
90 GOTO(failed, rc = -EPROTO);
94 if (body->mbo_eadatasize != symlen) {
95 CERROR("%s: inode "DFID": symlink length %d not expected %d\n",
96 ll_get_fsname(inode->i_sb, NULL, 0),
97 PFID(ll_inode2fid(inode)), body->mbo_eadatasize - 1,
99 GOTO(failed, rc = -EPROTO);
102 *symname = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_MD);
103 if (*symname == NULL ||
104 strnlen(*symname, symlen) != symlen - 1) {
105 /* not full/NULL terminated */
106 CERROR("%s: inode "DFID": symlink not NULL terminated string"
107 "of length %d\n", ll_get_fsname(inode->i_sb, NULL, 0),
108 PFID(ll_inode2fid(inode)), symlen - 1);
109 GOTO(failed, rc = -EPROTO);
112 OBD_ALLOC(lli->lli_symlink_name, symlen);
113 /* do not return an error if we cannot cache the symlink locally */
114 if (lli->lli_symlink_name) {
115 memcpy(lli->lli_symlink_name, *symname, symlen);
116 *symname = lli->lli_symlink_name;
124 #ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
125 static void ll_put_link(struct dentry *dentry,
126 struct nameidata *nd, void *cookie)
128 # ifdef HAVE_IOP_GET_LINK
129 static void ll_put_link(void *cookie)
131 static void ll_put_link(struct inode *unused, void *cookie)
135 ptlrpc_req_finished(cookie);
138 #ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
139 static void *ll_follow_link(struct dentry *dentry, struct nameidata *nd)
141 struct inode *inode = dentry->d_inode;
142 struct ptlrpc_request *request = NULL;
144 char *symname = NULL;
147 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. */
151 if (THREAD_SIZE < 8192 && current->link_count >= 6) {
153 } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
156 ll_inode_size_lock(inode);
157 rc = ll_readlink_internal(inode, &request, &symname);
158 ll_inode_size_unlock(inode);
161 ptlrpc_req_finished(request);
163 symname = ERR_PTR(rc);
166 nd_set_link(nd, symname);
167 /* symname may contain a pointer to the request message buffer,
168 * we delay request releasing until ll_put_link then.
173 # ifdef HAVE_IOP_GET_LINK
174 static const char *ll_get_link(struct dentry *dentry,
176 struct delayed_call *done)
178 struct ptlrpc_request *request;
179 char *symname = NULL;
183 CDEBUG(D_VFSTRACE, "VFS Op\n");
185 RETURN(ERR_PTR(-ECHILD));
186 ll_inode_size_lock(inode);
187 rc = ll_readlink_internal(inode, &request, &symname);
188 ll_inode_size_unlock(inode);
190 ptlrpc_req_finished(request);
194 /* symname may contain a pointer to the request message buffer,
195 * we delay request releasing then.
197 set_delayed_call(done, ll_put_link, request);
201 static const char *ll_follow_link(struct dentry *dentry, void **cookie)
203 struct inode *inode = d_inode(dentry);
204 struct ptlrpc_request *request;
205 char *symname = NULL;
209 CDEBUG(D_VFSTRACE, "VFS Op\n");
210 ll_inode_size_lock(inode);
211 rc = ll_readlink_internal(inode, &request, &symname);
212 ll_inode_size_unlock(inode);
214 ptlrpc_req_finished(request);
218 /* symname may contain a pointer to the request message buffer,
219 * we delay request releasing until ll_put_link then.
224 # endif /* HAVE_IOP_GET_LINK */
225 #endif /* HAVE_SYMLINK_OPS_USE_NAMEIDATA */
227 struct inode_operations ll_fast_symlink_inode_operations = {
228 .readlink = generic_readlink,
229 .setattr = ll_setattr,
230 #ifdef HAVE_IOP_GET_LINK
231 .get_link = ll_get_link,
233 .follow_link = ll_follow_link,
234 .put_link = ll_put_link,
236 .getattr = ll_getattr,
237 .permission = ll_inode_permission,
238 .setxattr = ll_setxattr,
239 .getxattr = ll_getxattr,
240 .listxattr = ll_listxattr,
241 .removexattr = ll_removexattr,