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) 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2012, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * Author: Nathan Rutman <nathan.rutman@sun.com>
34 * Kernel <-> userspace communication routines.
35 * Using pipes for all arches.
38 #define DEBUG_SUBSYSTEM S_CLASS
41 #include <obd_support.h>
42 #include <lustre_kernelcomm.h>
45 * libcfs_kkuc_msg_put - send an message from kernel to userspace
46 * @param fp to send the message to
47 * @param payload Payload data. First field of payload is always
50 int libcfs_kkuc_msg_put(struct file *filp, void *payload)
52 struct kuc_hdr *kuch = (struct kuc_hdr *)payload;
53 ssize_t count = kuch->kuc_msglen;
57 if (IS_ERR_OR_NULL(filp))
60 if (kuch->kuc_magic != KUC_MAGIC) {
61 CERROR("KernelComm: bad magic %x\n", kuch->kuc_magic);
66 rc = kernel_write(filp, payload, count, &offset);
75 CWARN("message send failed (%d)\n", rc);
77 CDEBUG(D_KUC, "Sent message rc=%d, fp=%p\n", rc, filp);
81 EXPORT_SYMBOL(libcfs_kkuc_msg_put);
84 * Broadcast groups are global across all mounted filesystems;
85 * i.e. registering for a group on 1 fs will get messages for that
88 /** A single group registration has a uid and a file pointer */
90 struct list_head kr_chain;
96 static struct list_head kkuc_groups[KUC_GRP_MAX + 1] = {};
97 /* Protect message sending against remove and adds */
98 static DECLARE_RWSEM(kg_sem);
100 /** Add a receiver to a broadcast group
101 * @param filp pipe to write into
102 * @param uid identifier for this receiver
103 * @param group group number
104 * @param data user data
106 int libcfs_kkuc_group_add(struct file *filp, int uid, unsigned int group,
107 void *data, size_t data_len)
109 struct kkuc_reg *reg;
111 if (group > KUC_GRP_MAX) {
112 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
116 /* fput in group_rem */
120 /* freed in group_rem */
121 reg = kmalloc(sizeof(*reg) + data_len, 0);
127 memcpy(reg->kr_data, data, data_len);
130 if (!kkuc_groups[group].next)
131 INIT_LIST_HEAD(&kkuc_groups[group]);
132 list_add(®->kr_chain, &kkuc_groups[group]);
135 CDEBUG(D_KUC, "Added uid=%d fp=%p to group %d\n", uid, filp, group);
139 EXPORT_SYMBOL(libcfs_kkuc_group_add);
141 int libcfs_kkuc_group_rem(int uid, unsigned int group)
143 struct kkuc_reg *reg, *next;
145 if (!kkuc_groups[group].next)
149 /* Broadcast a shutdown message */
152 lh.kuc_magic = KUC_MAGIC;
153 lh.kuc_transport = KUC_TRANSPORT_GENERIC;
154 lh.kuc_msgtype = KUC_MSG_SHUTDOWN;
155 lh.kuc_msglen = sizeof(lh);
156 libcfs_kkuc_group_put(group, &lh);
160 list_for_each_entry_safe(reg, next, &kkuc_groups[group], kr_chain) {
161 if (!uid || (uid == reg->kr_uid)) {
162 list_del(®->kr_chain);
163 CDEBUG(D_KUC, "Removed uid=%d fp=%p from group %d\n",
164 reg->kr_uid, reg->kr_fp, group);
174 EXPORT_SYMBOL(libcfs_kkuc_group_rem);
176 int libcfs_kkuc_group_put(unsigned int group, void *payload)
178 struct kkuc_reg *reg;
183 list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
185 rc = libcfs_kkuc_msg_put(reg->kr_fp, payload);
188 } else if (rc == -EPIPE) {
197 * don't return an error if the message has been delivered
198 * at least to one agent
205 EXPORT_SYMBOL(libcfs_kkuc_group_put);
208 * Calls a callback function for each link of the given kuc group.
209 * @param group the group to call the function on.
210 * @param cb_func the function to be called.
211 * @param cb_arg extra argument to be passed to the callback function.
213 int libcfs_kkuc_group_foreach(unsigned int group, libcfs_kkuc_cb_t cb_func,
216 struct kkuc_reg *reg;
219 if (group > KUC_GRP_MAX) {
220 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
224 /* no link for this group */
225 if (!kkuc_groups[group].next)
229 list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
231 rc = cb_func(reg->kr_data, cb_arg);
237 EXPORT_SYMBOL(libcfs_kkuc_group_foreach);