-/*
- * 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, 2013, 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 <libcfs/libcfs.h>
-
-#ifdef LUSTRE_UTILS
-/* This is the userspace side. */
-
-/** Start the userspace side of a KUC pipe.
- * @param link Private descriptor for pipe/socket.
- * @param groups KUC broadcast group to listen to
- * (can be null for unicast to this pid)
- * @param rfd_flags flags for read side of pipe (e.g. O_NONBLOCK)
- */
-int libcfs_ukuc_start(lustre_kernelcomm *link, int group, int rfd_flags)
-{
- int pfd[2];
- int rc;
-
- link->lk_rfd = link->lk_wfd = LK_NOFD;
-
- if (pipe(pfd) < 0)
- return -errno;
-
- if (fcntl(pfd[0], F_SETFL, rfd_flags) < 0) {
- rc = -errno;
- close(pfd[0]);
- close(pfd[1]);
- return rc;
- }
-
- memset(link, 0, sizeof(*link));
- link->lk_rfd = pfd[0];
- link->lk_wfd = pfd[1];
- link->lk_group = group;
- link->lk_uid = getpid();
- return 0;
-}
-
-int libcfs_ukuc_stop(lustre_kernelcomm *link)
-{
- int rc;
-
- if (link->lk_wfd != LK_NOFD)
- close(link->lk_wfd);
- rc = close(link->lk_rfd);
- link->lk_rfd = link->lk_wfd = LK_NOFD;
- return rc;
-}
-
-/** Returns the file descriptor for the read side of the pipe,
- * to be used with poll/select.
- * @param link Private descriptor for pipe/socket.
- */
-int libcfs_ukuc_get_rfd(lustre_kernelcomm *link)
-{
- return link->lk_rfd;
-}
-
-#define lhsz sizeof(*kuch)
-
-/** Read a message from the link.
- * Allocates memory, returns handle
- *
- * @param link Private descriptor for pipe/socket.
- * @param buf Buffer to read into, must include size for kuc_hdr
- * @param maxsize Maximum message size allowed
- * @param transport Only listen to messages on this transport
- * (and the generic transport)
- */
-int libcfs_ukuc_msg_get(lustre_kernelcomm *link, char *buf, int maxsize,
- int transport)
-{
- struct kuc_hdr *kuch;
- int rc = 0;
-
- memset(buf, 0, maxsize);
-
- CDEBUG(D_KUC, "Waiting for message from kernel on fd %d\n",
- link->lk_rfd);
-
- while (1) {
- /* Read header first to get message size */
- rc = read(link->lk_rfd, buf, lhsz);
- if (rc <= 0) {
- rc = -errno;
- break;
- }
- kuch = (struct kuc_hdr *)buf;
-
- CDEBUG(D_KUC, "Received message mg=%x t=%d m=%d l=%d\n",
- kuch->kuc_magic, kuch->kuc_transport, kuch->kuc_msgtype,
- kuch->kuc_msglen);
-
- if (kuch->kuc_magic != KUC_MAGIC) {
- CERROR("bad message magic %x != %x\n",
- kuch->kuc_magic, KUC_MAGIC);
- rc = -EPROTO;
- break;
- }
-
- if (kuch->kuc_msglen > maxsize) {
- rc = -EMSGSIZE;
- break;
- }
-
- /* Read payload */
- rc = read(link->lk_rfd, buf + lhsz, kuch->kuc_msglen - lhsz);
- if (rc < 0) {
- rc = -errno;
- break;
- }
- if (rc < (kuch->kuc_msglen - lhsz)) {
- CERROR("short read: got %d of %d bytes\n",
- rc, kuch->kuc_msglen);
- rc = -EPROTO;
- break;
- }
-
- if (kuch->kuc_transport == transport ||
- kuch->kuc_transport == KUC_TRANSPORT_GENERIC) {
- return 0;
- }
- /* Drop messages for other transports */
- }
- return rc;
-}
-
-#else /* LUSTRE_UTILS */
-/* 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;
- 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;
- }
-
-#ifdef __KERNEL__
- {
- loff_t offset = 0;
- rc = filp_user_write(filp, payload, kuch->kuc_msglen,
- &offset);
- }
-#endif
-
- 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;
- void *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
- * @param data user data
- */
-int libcfs_kkuc_group_add(struct file *filp, int uid, int group, void *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, void **pdata)
-{
- struct kkuc_reg *reg, *next;
- ENTRY;
-
- 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);
- if (pdata != NULL)
- *pdata = reg->kr_data;
- 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;
- ENTRY;
-
- down_write(&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_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(int group, libcfs_kkuc_cb_t cb_func,
- void *cb_arg)
-{
- struct kkuc_reg *reg;
- int rc = 0;
- ENTRY;
-
- 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_read(&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_read(&kg_sem);
-
- RETURN(rc);
-}
-EXPORT_SYMBOL(libcfs_kkuc_group_foreach);
-
-#endif /* LUSTRE_UTILS */
-
git://git.whamcloud.com / fs / lustre-release.git / commitdiff