--- /dev/null
+/*
+ * 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.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * 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/linux/libcfs/libcfs.h"
+
+/* This is the kernel side (liblustre as well). */
+
+/**
+ * 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 = -ENOSYS;
+
+ if (filp == NULL || IS_ERR(filp))
+ return -EBADF;
+
+ if (kuch->kuc_magic != KUC_MAGIC) {
+ CERROR("KernelComm: bad magic %x\n", kuch->kuc_magic);
+ return -ENOSYS;
+ }
+
+ 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;
+ __u32 kr_data;
+};
+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
+ */
+int libcfs_kkuc_group_add(struct file *filp, int uid, int group, __u32 data)
+{
+ 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 == NULL)
+ return -EBADF;
+
+ /* freed in group_rem */
+ reg = kmalloc(sizeof(*reg), 0);
+ if (reg == NULL)
+ return -ENOMEM;
+
+ reg->kr_fp = filp;
+ reg->kr_uid = uid;
+ reg->kr_data = data;
+
+ down_write(&kg_sem);
+ if (kkuc_groups[group].next == NULL)
+ 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, int group)
+{
+ struct kkuc_reg *reg, *next;
+
+ if (kkuc_groups[group].next == NULL)
+ return 0;
+
+ if (uid == 0) {
+ /* 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 == 0) || (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 != NULL)
+ fput(reg->kr_fp);
+ kfree(reg);
+ }
+ }
+ up_write(&kg_sem);
+
+ return 0;
+}
+EXPORT_SYMBOL(libcfs_kkuc_group_rem);
+
+int libcfs_kkuc_group_put(int group, void *payload)
+{
+ struct kkuc_reg *reg;
+ int rc = 0;
+ int one_success = 0;
+
+ down_read(&kg_sem);
+ list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
+ if (reg->kr_fp != NULL) {
+ rc = libcfs_kkuc_msg_put(reg->kr_fp, payload);
+ if (rc == 0)
+ one_success = 1;
+ else if (rc == -EPIPE) {
+ fput(reg->kr_fp);
+ reg->kr_fp = NULL;
+ }
+ }
+ }
+ up_read(&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 iextra argument to be passed to the callback function.
+ */
+int libcfs_kkuc_group_foreach(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 == NULL)
+ return 0;
+
+ down_write(&kg_sem);
+ list_for_each_entry(reg, &kkuc_groups[group], kr_chain) {
+ if (reg->kr_fp != NULL)
+ rc = cb_func(reg->kr_data, cb_arg);
+ }
+ up_write(&kg_sem);
+
+ return rc;
+}
+EXPORT_SYMBOL(libcfs_kkuc_group_foreach);
Code Review / kvmfornfv.git / blobdiff