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) 2015, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
31 * Author: Nathan Rutman <nathan.rutman@sun.com>
33 * Kernel <-> userspace communication routines.
34 * Using pipes for all arches.
37 #define DEBUG_SUBSYSTEM S_CLASS
40 #include <obd_support.h>
41 #include <lustre_kernelcomm.h>
43 /* write a userspace buffer to disk.
44 * NOTE: this returns 0 on success, not the number of bytes written. */
46 filp_user_write(struct file *filp, const void *buf, size_t count,
54 while ((ssize_t)count > 0) {
55 size = vfs_write(filp, (const void __user *)buf, count, offset);
68 * libcfs_kkuc_msg_put - send an message from kernel to userspace
69 * @param fp to send the message to
70 * @param payload Payload data. First field of payload is always
73 int libcfs_kkuc_msg_put(struct file *filp, void *payload)
75 struct kuc_hdr *kuch = (struct kuc_hdr *)payload;
79 if (filp == NULL || IS_ERR(filp))
82 if (kuch->kuc_magic != KUC_MAGIC) {
83 CERROR("KernelComm: bad magic %x\n", kuch->kuc_magic);
87 rc = filp_user_write(filp, payload, kuch->kuc_msglen, &offset);
89 CWARN("message send failed (%d)\n", rc);
91 CDEBUG(D_KUC, "Sent message rc=%d, fp=%p\n", rc, filp);
95 EXPORT_SYMBOL(libcfs_kkuc_msg_put);
97 /* Broadcast groups are global across all mounted filesystems;
98 * i.e. registering for a group on 1 fs will get messages for that
99 * group from any fs */
100 /** A single group registration has a uid and a file pointer */
102 struct list_head kr_chain;
108 static struct list_head kkuc_groups[KUC_GRP_MAX + 1];
109 /* Protect message sending against remove and adds */
110 static DECLARE_RWSEM(kg_sem);
112 static inline bool libcfs_kkuc_group_is_valid(int group)
114 return 0 <= group && group < ARRAY_SIZE(kkuc_groups);
117 void libcfs_kkuc_init(void)
121 for (group = 0; group < ARRAY_SIZE(kkuc_groups); group++)
122 INIT_LIST_HEAD(&kkuc_groups[group]);
125 /** Add a receiver to a broadcast group
126 * @param filp pipe to write into
127 * @param uid identifier for this receiver
128 * @param group group number
129 * @param data user data
131 int libcfs_kkuc_group_add(struct file *filp, int uid, int group,
132 void *data, size_t data_len)
134 struct kkuc_reg *reg;
136 if (!libcfs_kkuc_group_is_valid(group)) {
137 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
141 /* fput in group_rem */
145 /* freed in group_rem */
146 reg = kmalloc(sizeof(*reg) + data_len, 0);
152 memcpy(reg->kr_data, data, data_len);
155 list_add(®->kr_chain, &kkuc_groups[group]);
158 CDEBUG(D_KUC, "Added uid=%d fp=%p to group %d\n", uid, filp, group);
162 EXPORT_SYMBOL(libcfs_kkuc_group_add);
164 int libcfs_kkuc_group_rem(int uid, int group)
166 struct kkuc_reg *reg, *next;
169 if (!libcfs_kkuc_group_is_valid(group)) {
170 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
175 /* Broadcast a shutdown message */
178 lh.kuc_magic = KUC_MAGIC;
179 lh.kuc_transport = KUC_TRANSPORT_GENERIC;
180 lh.kuc_msgtype = KUC_MSG_SHUTDOWN;
181 lh.kuc_msglen = sizeof(lh);
182 libcfs_kkuc_group_put(group, &lh);
186 list_for_each_entry_safe(reg, next, &kkuc_groups[group], kr_chain) {
187 if ((uid == 0) || (uid == reg->kr_uid)) {
188 list_del(®->kr_chain);
189 CDEBUG(D_KUC, "Removed uid=%d fp=%p from group %d\n",
190 reg->kr_uid, reg->kr_fp, group);
191 if (reg->kr_fp != NULL)
200 EXPORT_SYMBOL(libcfs_kkuc_group_rem);
202 int libcfs_kkuc_group_put(int group, void *payload)
204 struct kkuc_reg *reg;
209 if (!libcfs_kkuc_group_is_valid(group)) {
210 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
216 if (unlikely(list_empty(&kkuc_groups[group])) ||
217 unlikely(OBD_FAIL_CHECK(OBD_FAIL_MDS_HSM_CT_REGISTER_NET))) {
218 /* no agent have fully registered, CDT will retry */
223 list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
224 if (reg->kr_fp != NULL) {
225 rc = libcfs_kkuc_msg_put(reg->kr_fp, payload);
228 else if (rc == -EPIPE) {
236 /* don't return an error if the message has been delivered
237 * at least to one agent */
243 EXPORT_SYMBOL(libcfs_kkuc_group_put);
246 * Calls a callback function for each link of the given kuc group.
247 * @param group the group to call the function on.
248 * @param cb_func the function to be called.
249 * @param cb_arg extra argument to be passed to the callback function.
251 int libcfs_kkuc_group_foreach(int group, libcfs_kkuc_cb_t cb_func,
254 struct kkuc_reg *reg;
258 if (!libcfs_kkuc_group_is_valid(group)) {
259 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
264 list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
265 if (reg->kr_fp != NULL)
266 rc = cb_func(reg->kr_data, cb_arg);
272 EXPORT_SYMBOL(libcfs_kkuc_group_foreach);