| /* |
| * GPL HEADER START |
| * |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 only, |
| * as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License version 2 for more details (a copy is included |
| * in the LICENSE file that accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License |
| * version 2 along with this program; If not, see |
| * http://www.gnu.org/licenses/gpl-2.0.html |
| * |
| * GPL HEADER END |
| */ |
| /* |
| * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. |
| * Use is subject to license terms. |
| * |
| * Copyright (c) 2012, Intel Corporation. |
| */ |
| /* |
| * This file is part of Lustre, http://www.lustre.org/ |
| * Lustre is a trademark of Sun Microsystems, Inc. |
| * |
| * Author: Nathan Rutman <nathan.rutman@sun.com> |
| * |
| * Kernel <-> userspace communication routines. |
| * Using pipes for all arches. |
| */ |
| |
| #define DEBUG_SUBSYSTEM S_CLASS |
| #define D_KUC D_OTHER |
| |
| #include "../include/obd_support.h" |
| #include "../include/lustre_kernelcomm.h" |
| |
| /** |
| * libcfs_kkuc_msg_put - send an message from kernel to userspace |
| * @param fp to send the message to |
| * @param payload Payload data. First field of payload is always |
| * struct kuc_hdr |
| */ |
| int libcfs_kkuc_msg_put(struct file *filp, void *payload) |
| { |
| struct kuc_hdr *kuch = (struct kuc_hdr *)payload; |
| ssize_t count = kuch->kuc_msglen; |
| loff_t offset = 0; |
| mm_segment_t fs; |
| int rc = -ENXIO; |
| |
| if (IS_ERR_OR_NULL(filp)) |
| return -EBADF; |
| |
| if (kuch->kuc_magic != KUC_MAGIC) { |
| CERROR("KernelComm: bad magic %x\n", kuch->kuc_magic); |
| return rc; |
| } |
| |
| fs = get_fs(); |
| set_fs(KERNEL_DS); |
| while (count > 0) { |
| rc = vfs_write(filp, (void __force __user *)payload, |
| count, &offset); |
| if (rc < 0) |
| break; |
| count -= rc; |
| payload += rc; |
| rc = 0; |
| } |
| set_fs(fs); |
| |
| if (rc < 0) |
| CWARN("message send failed (%d)\n", rc); |
| else |
| CDEBUG(D_KUC, "Sent message rc=%d, fp=%p\n", rc, filp); |
| |
| return rc; |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_msg_put); |
| |
| /* |
| * Broadcast groups are global across all mounted filesystems; |
| * i.e. registering for a group on 1 fs will get messages for that |
| * group from any fs |
| */ |
| /** A single group registration has a uid and a file pointer */ |
| struct kkuc_reg { |
| struct list_head kr_chain; |
| int kr_uid; |
| struct file *kr_fp; |
| char kr_data[0]; |
| }; |
| |
| static struct list_head kkuc_groups[KUC_GRP_MAX + 1] = {}; |
| /* Protect message sending against remove and adds */ |
| static DECLARE_RWSEM(kg_sem); |
| |
| /** Add a receiver to a broadcast group |
| * @param filp pipe to write into |
| * @param uid identifier for this receiver |
| * @param group group number |
| * @param data user data |
| */ |
| int libcfs_kkuc_group_add(struct file *filp, int uid, unsigned int group, |
| void *data, size_t data_len) |
| { |
| struct kkuc_reg *reg; |
| |
| if (group > KUC_GRP_MAX) { |
| CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group); |
| return -EINVAL; |
| } |
| |
| /* fput in group_rem */ |
| if (!filp) |
| return -EBADF; |
| |
| /* freed in group_rem */ |
| reg = kmalloc(sizeof(*reg) + data_len, 0); |
| if (!reg) |
| return -ENOMEM; |
| |
| reg->kr_fp = filp; |
| reg->kr_uid = uid; |
| memcpy(reg->kr_data, data, data_len); |
| |
| down_write(&kg_sem); |
| if (!kkuc_groups[group].next) |
| INIT_LIST_HEAD(&kkuc_groups[group]); |
| list_add(®->kr_chain, &kkuc_groups[group]); |
| up_write(&kg_sem); |
| |
| CDEBUG(D_KUC, "Added uid=%d fp=%p to group %d\n", uid, filp, group); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_group_add); |
| |
| int libcfs_kkuc_group_rem(int uid, unsigned int group) |
| { |
| struct kkuc_reg *reg, *next; |
| |
| if (!kkuc_groups[group].next) |
| return 0; |
| |
| if (!uid) { |
| /* Broadcast a shutdown message */ |
| struct kuc_hdr lh; |
| |
| lh.kuc_magic = KUC_MAGIC; |
| lh.kuc_transport = KUC_TRANSPORT_GENERIC; |
| lh.kuc_msgtype = KUC_MSG_SHUTDOWN; |
| lh.kuc_msglen = sizeof(lh); |
| libcfs_kkuc_group_put(group, &lh); |
| } |
| |
| down_write(&kg_sem); |
| list_for_each_entry_safe(reg, next, &kkuc_groups[group], kr_chain) { |
| if (!uid || (uid == reg->kr_uid)) { |
| list_del(®->kr_chain); |
| CDEBUG(D_KUC, "Removed uid=%d fp=%p from group %d\n", |
| reg->kr_uid, reg->kr_fp, group); |
| if (reg->kr_fp) |
| fput(reg->kr_fp); |
| kfree(reg); |
| } |
| } |
| up_write(&kg_sem); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_group_rem); |
| |
| int libcfs_kkuc_group_put(unsigned int group, void *payload) |
| { |
| struct kkuc_reg *reg; |
| int rc = 0; |
| int one_success = 0; |
| |
| down_write(&kg_sem); |
| list_for_each_entry(reg, &kkuc_groups[group], kr_chain) { |
| if (reg->kr_fp) { |
| rc = libcfs_kkuc_msg_put(reg->kr_fp, payload); |
| if (!rc) { |
| one_success = 1; |
| } else if (rc == -EPIPE) { |
| fput(reg->kr_fp); |
| reg->kr_fp = NULL; |
| } |
| } |
| } |
| up_write(&kg_sem); |
| |
| /* |
| * don't return an error if the message has been delivered |
| * at least to one agent |
| */ |
| if (one_success) |
| rc = 0; |
| |
| return rc; |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_group_put); |
| |
| /** |
| * Calls a callback function for each link of the given kuc group. |
| * @param group the group to call the function on. |
| * @param cb_func the function to be called. |
| * @param cb_arg extra argument to be passed to the callback function. |
| */ |
| int libcfs_kkuc_group_foreach(unsigned int group, libcfs_kkuc_cb_t cb_func, |
| void *cb_arg) |
| { |
| struct kkuc_reg *reg; |
| int rc = 0; |
| |
| if (group > KUC_GRP_MAX) { |
| CDEBUG(D_WARNING, "Kernelcomm: bad group %d\n", group); |
| return -EINVAL; |
| } |
| |
| /* no link for this group */ |
| if (!kkuc_groups[group].next) |
| return 0; |
| |
| down_read(&kg_sem); |
| list_for_each_entry(reg, &kkuc_groups[group], kr_chain) { |
| if (reg->kr_fp) |
| rc = cb_func(reg->kr_data, cb_arg); |
| } |
| up_read(&kg_sem); |
| |
| return rc; |
| } |
| EXPORT_SYMBOL(libcfs_kkuc_group_foreach); |