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, 2017, 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
39 #include <linux/file.h>
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 = cfs_kernel_write(filp, payload, count, &offset);
75 CWARN("message send failed (%d)\n", rc);
77 CDEBUG(D_HSM, "Sent message rc=%d, fp=%p\n", rc, filp);
81 EXPORT_SYMBOL(libcfs_kkuc_msg_put);
83 /* Broadcast groups are global across all mounted filesystems;
84 * i.e. registering for a group on 1 fs will get messages for that
85 * group from any fs */
86 /** A single group registration has a uid and a file pointer */
88 struct list_head kr_chain;
89 struct obd_uuid kr_uuid;
95 static struct list_head kkuc_groups[KUC_GRP_MAX + 1];
96 /* Protect message sending against remove and adds */
97 static DECLARE_RWSEM(kg_sem);
99 static inline bool libcfs_kkuc_group_is_valid(int group)
101 return 0 <= group && group < ARRAY_SIZE(kkuc_groups);
104 void libcfs_kkuc_init(void)
108 for (group = 0; group < ARRAY_SIZE(kkuc_groups); group++)
109 INIT_LIST_HEAD(&kkuc_groups[group]);
112 /** Add a receiver to a broadcast group
113 * @param filp pipe to write into
114 * @param uid identifier for this receiver
115 * @param group group number
116 * @param data user data
118 int libcfs_kkuc_group_add(struct file *filp, const struct obd_uuid *uuid,
119 int uid, int group, void *data, size_t data_len)
121 struct kkuc_reg *reg;
123 if (!libcfs_kkuc_group_is_valid(group)) {
124 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
128 /* fput in group_rem */
132 /* freed in group_rem */
133 reg = kzalloc(sizeof(*reg) + data_len, 0);
137 reg->kr_uuid = *uuid;
140 memcpy(reg->kr_data, data, data_len);
143 list_add(®->kr_chain, &kkuc_groups[group]);
146 CDEBUG(D_HSM, "Added uid=%d fp=%p to group %d\n", uid, filp, group);
150 EXPORT_SYMBOL(libcfs_kkuc_group_add);
152 int libcfs_kkuc_group_rem(const struct obd_uuid *uuid, int uid, int group)
154 struct kkuc_reg *reg, *next;
157 if (!libcfs_kkuc_group_is_valid(group)) {
158 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
163 /* Broadcast a shutdown message */
166 lh.kuc_magic = KUC_MAGIC;
167 lh.kuc_transport = KUC_TRANSPORT_GENERIC;
168 lh.kuc_msgtype = KUC_MSG_SHUTDOWN;
169 lh.kuc_msglen = sizeof(lh);
170 libcfs_kkuc_group_put(uuid, group, &lh);
174 list_for_each_entry_safe(reg, next, &kkuc_groups[group], kr_chain) {
175 if (obd_uuid_equals(uuid, ®->kr_uuid) &&
176 (uid == 0 || uid == reg->kr_uid)) {
177 list_del(®->kr_chain);
178 CDEBUG(D_HSM, "Removed uid=%d fp=%p from group %d\n",
179 reg->kr_uid, reg->kr_fp, group);
180 if (reg->kr_fp != NULL)
189 EXPORT_SYMBOL(libcfs_kkuc_group_rem);
191 int libcfs_kkuc_group_put(const struct obd_uuid *uuid, int group, void *payload)
193 struct kkuc_reg *reg;
198 if (!libcfs_kkuc_group_is_valid(group)) {
199 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
205 if (unlikely(list_empty(&kkuc_groups[group])) ||
206 unlikely(OBD_FAIL_CHECK(OBD_FAIL_MDS_HSM_CT_REGISTER_NET))) {
207 /* no agent have fully registered, CDT will retry */
212 list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
213 if (obd_uuid_equals(uuid, ®->kr_uuid) &&
214 reg->kr_fp != NULL) {
215 rc = libcfs_kkuc_msg_put(reg->kr_fp, payload);
218 else if (rc == -EPIPE) {
226 /* don't return an error if the message has been delivered
227 * at least to one agent */
233 EXPORT_SYMBOL(libcfs_kkuc_group_put);
236 * Calls a callback function for each link of the given kuc group.
237 * @param group the group to call the function on.
238 * @param cb_func the function to be called.
239 * @param cb_arg extra argument to be passed to the callback function.
241 int libcfs_kkuc_group_foreach(const struct obd_uuid *uuid, int group,
242 libcfs_kkuc_cb_t cb_func, void *cb_arg)
244 struct kkuc_reg *reg;
248 if (!libcfs_kkuc_group_is_valid(group)) {
249 CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group);
254 list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
255 if (obd_uuid_equals(uuid, ®->kr_uuid) && reg->kr_fp != NULL)
256 rc = cb_func(reg->kr_data, cb_arg);
262 EXPORT_SYMBOL(libcfs_kkuc_group_foreach);