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* 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);
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