Merge tag 'dlm-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm (c024a811) · Commits · 戴 / test

fs/dlm/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -4,6 +4,7 @@ menuconfig DLM
		depends on INET
		depends on SYSFS && CONFIGFS_FS && (IPV6 \|\| IPV6=n)
		select IP_SCTP
		select SRCU
		help
		A general purpose distributed lock manager for kernel or userspace
		applications.

fs/dlm/config.c

+41 −25

Original line number	Diff line number	Diff line
		@@ -125,7 +125,7 @@ static ssize_t cluster_cluster_name_store(struct config_item *item,
		CONFIGFS_ATTR(cluster_, cluster_name);

		static ssize_t cluster_set(struct dlm_cluster cl, unsigned int cl_field,
		int *info_field, int check_zero,
		int info_field, bool (check_cb)(unsigned int x),
		const char *buf, size_t len)
		{
		unsigned int x;
		@@ -137,7 +137,7 @@ static ssize_t cluster_set(struct dlm_cluster cl, unsigned int cl_field,
		if (rc)
		return rc;

		if (check_zero && !x)
		if (check_cb && check_cb(x))
		return -EINVAL;

		*cl_field = x;
		@@ -146,13 +146,13 @@ static ssize_t cluster_set(struct dlm_cluster cl, unsigned int cl_field,
		return len;
		}

		#define CLUSTER_ATTR(name, check_zero) \
		#define CLUSTER_ATTR(name, check_cb) \
		static ssize_t cluster_##name##_store(struct config_item *item, \
		const char *buf, size_t len) \
		{ \
		struct dlm_cluster *cl = config_item_to_cluster(item); \
		return cluster_set(cl, &cl->cl_##name, &dlm_config.ci_##name, \
		check_zero, buf, len); \
		check_cb, buf, len); \
		} \
		static ssize_t cluster_##name##_show(struct config_item item, char buf) \
		{ \
		@@ -161,20 +161,30 @@ static ssize_t cluster_##name##_show(struct config_item item, char buf) \
		} \
		CONFIGFS_ATTR(cluster_, name);

		CLUSTER_ATTR(tcp_port, 1);
		CLUSTER_ATTR(buffer_size, 1);
		CLUSTER_ATTR(rsbtbl_size, 1);
		CLUSTER_ATTR(recover_timer, 1);
		CLUSTER_ATTR(toss_secs, 1);
		CLUSTER_ATTR(scan_secs, 1);
		CLUSTER_ATTR(log_debug, 0);
		CLUSTER_ATTR(log_info, 0);
		CLUSTER_ATTR(protocol, 0);
		CLUSTER_ATTR(mark, 0);
		CLUSTER_ATTR(timewarn_cs, 1);
		CLUSTER_ATTR(waitwarn_us, 0);
		CLUSTER_ATTR(new_rsb_count, 0);
		CLUSTER_ATTR(recover_callbacks, 0);
		static bool dlm_check_zero(unsigned int x)
		{
		return !x;
		}

		static bool dlm_check_buffer_size(unsigned int x)
		{
		return (x < DEFAULT_BUFFER_SIZE);
		}

		CLUSTER_ATTR(tcp_port, dlm_check_zero);
		CLUSTER_ATTR(buffer_size, dlm_check_buffer_size);
		CLUSTER_ATTR(rsbtbl_size, dlm_check_zero);
		CLUSTER_ATTR(recover_timer, dlm_check_zero);
		CLUSTER_ATTR(toss_secs, dlm_check_zero);
		CLUSTER_ATTR(scan_secs, dlm_check_zero);
		CLUSTER_ATTR(log_debug, NULL);
		CLUSTER_ATTR(log_info, NULL);
		CLUSTER_ATTR(protocol, NULL);
		CLUSTER_ATTR(mark, NULL);
		CLUSTER_ATTR(timewarn_cs, dlm_check_zero);
		CLUSTER_ATTR(waitwarn_us, NULL);
		CLUSTER_ATTR(new_rsb_count, NULL);
		CLUSTER_ATTR(recover_callbacks, NULL);

		static struct configfs_attribute *cluster_attrs[] = {
		[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port,
		@@ -221,6 +231,7 @@ struct dlm_space {
		struct list_head members;
		struct mutex members_lock;
		int members_count;
		struct dlm_nodes *nds;
		};

		struct dlm_comms {
		@@ -430,6 +441,7 @@ static struct config_group make_space(struct config_group g, const char *name)
		INIT_LIST_HEAD(&sp->members);
		mutex_init(&sp->members_lock);
		sp->members_count = 0;
		sp->nds = nds;
		return &sp->group;

		fail:
		@@ -451,6 +463,7 @@ static void drop_space(struct config_group g, struct config_item i)
		static void release_space(struct config_item *i)
		{
		struct dlm_space *sp = config_item_to_space(i);
		kfree(sp->nds);
		kfree(sp);
		}

		@@ -857,18 +870,22 @@ int dlm_comm_seq(int nodeid, uint32_t *seq)
		return 0;
		}

		int dlm_comm_mark(int nodeid, unsigned int *mark)
		void dlm_comm_mark(int nodeid, unsigned int *mark)
		{
		struct dlm_comm *cm;

		cm = get_comm(nodeid);
		if (!cm)
		return -ENOENT;
		if (!cm) {
		*mark = dlm_config.ci_mark;
		return;
		}

		if (cm->mark)
		*mark = cm->mark;
		put_comm(cm);
		else
		*mark = dlm_config.ci_mark;

		return 0;
		put_comm(cm);
		}

		int dlm_our_nodeid(void)
		@@ -889,7 +906,6 @@ int dlm_our_addr(struct sockaddr_storage *addr, int num)

		/* Config file defaults */
		#define DEFAULT_TCP_PORT 21064
		#define DEFAULT_BUFFER_SIZE 4096
		#define DEFAULT_RSBTBL_SIZE 1024
		#define DEFAULT_RECOVER_TIMER 5
		#define DEFAULT_TOSS_SECS 10

fs/dlm/config.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -12,6 +12,8 @@
		#ifndef __CONFIG_DOT_H__
		#define __CONFIG_DOT_H__

		#define DEFAULT_BUFFER_SIZE 4096

		struct dlm_config_node {
		int nodeid;
		int weight;
		@@ -46,7 +48,7 @@ void dlm_config_exit(void);
		int dlm_config_nodes(char lsname, struct dlm_config_node *nodes_out,
		int *count_out);
		int dlm_comm_seq(int nodeid, uint32_t *seq);
		int dlm_comm_mark(int nodeid, unsigned int *mark);
		void dlm_comm_mark(int nodeid, unsigned int *mark);
		int dlm_our_nodeid(void);
		int dlm_our_addr(struct sockaddr_storage *addr, int num);

fs/dlm/lowcomms.c

+161 −168

Original line number	Diff line number	Diff line
		@@ -65,40 +65,6 @@
		#define MAX_SEND_MSG_COUNT 25
		#define DLM_SHUTDOWN_WAIT_TIMEOUT msecs_to_jiffies(10000)

		struct cbuf {
		unsigned int base;
		unsigned int len;
		unsigned int mask;
		};

		static void cbuf_add(struct cbuf *cb, int n)
		{
		cb->len += n;
		}

		static int cbuf_data(struct cbuf *cb)
		{
		return ((cb->base + cb->len) & cb->mask);
		}

		static void cbuf_init(struct cbuf *cb, int size)
		{
		cb->base = cb->len = 0;
		cb->mask = size-1;
		}

		static void cbuf_eat(struct cbuf *cb, int n)
		{
		cb->len -= n;
		cb->base += n;
		cb->base &= cb->mask;
		}

		static bool cbuf_empty(struct cbuf *cb)
		{
		return cb->len == 0;
		}

		struct connection {
		struct socket sock; / NULL if not connected */
		uint32_t nodeid; /* So we know who we are in the list */
		@@ -117,8 +83,6 @@ struct connection {
		int (rx_action) (struct connection ); /* What to do when active */
		void (connect_action) (struct connection ); /* What to do to connect */
		void (shutdown_action)(struct connection con); /* What to do to shutdown */
		struct page *rx_page;
		struct cbuf cb;
		int retries;
		#define MAX_CONNECT_RETRIES 3
		struct hlist_node list;
		@@ -126,6 +90,10 @@ struct connection {
		struct work_struct rwork; /* Receive workqueue */
		struct work_struct swork; /* Send workqueue */
		wait_queue_head_t shutdown_wait; /* wait for graceful shutdown */
		unsigned char *rx_buf;
		int rx_buflen;
		int rx_leftover;
		struct rcu_head rcu;
		};
		#define sock2con(x) ((struct connection *)(x)->sk_user_data)

		@@ -167,8 +135,8 @@ static struct workqueue_struct *recv_workqueue;
		static struct workqueue_struct *send_workqueue;

		static struct hlist_head connection_hash[CONN_HASH_SIZE];
		static DEFINE_MUTEX(connections_lock);
		static struct kmem_cache *con_cache;
		static DEFINE_SPINLOCK(connections_lock);
		DEFINE_STATIC_SRCU(connections_srcu);

		static void process_recv_sockets(struct work_struct *work);
		static void process_send_sockets(struct work_struct *work);
		@@ -184,15 +152,20 @@ static inline int nodeid_hash(int nodeid)

		static struct connection *__find_con(int nodeid)
		{
		int r;
		int r, idx;
		struct connection *con;

		r = nodeid_hash(nodeid);

		hlist_for_each_entry(con, &connection_hash[r], list) {
		if (con->nodeid == nodeid)
		idx = srcu_read_lock(&connections_srcu);
		hlist_for_each_entry_rcu(con, &connection_hash[r], list) {
		if (con->nodeid == nodeid) {
		srcu_read_unlock(&connections_srcu, idx);
		return con;
		}
		}
		srcu_read_unlock(&connections_srcu, idx);

		return NULL;
		}

		@@ -200,21 +173,25 @@ static struct connection *__find_con(int nodeid)
		* If 'allocation' is zero then we don't attempt to create a new
		* connection structure for this node.
		*/
		static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
		static struct connection *nodeid2con(int nodeid, gfp_t alloc)
		{
		struct connection *con = NULL;
		struct connection con, tmp;
		int r;

		con = __find_con(nodeid);
		if (con \|\| !alloc)
		return con;

		con = kmem_cache_zalloc(con_cache, alloc);
		con = kzalloc(sizeof(*con), alloc);
		if (!con)
		return NULL;

		r = nodeid_hash(nodeid);
		hlist_add_head(&con->list, &connection_hash[r]);
		con->rx_buflen = dlm_config.ci_buffer_size;
		con->rx_buf = kmalloc(con->rx_buflen, GFP_NOFS);
		if (!con->rx_buf) {
		kfree(con);
		return NULL;
		}

		con->nodeid = nodeid;
		mutex_init(&con->sock_mutex);
		@@ -233,31 +210,41 @@ static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
		con->rx_action = zerocon->rx_action;
		}

		r = nodeid_hash(nodeid);

		spin_lock(&connections_lock);
		/* Because multiple workqueues/threads calls this function it can
		* race on multiple cpu's. Instead of locking hot path __find_con()
		* we just check in rare cases of recently added nodes again
		* under protection of connections_lock. If this is the case we
		* abort our connection creation and return the existing connection.
		*/
		tmp = __find_con(nodeid);
		if (tmp) {
		spin_unlock(&connections_lock);
		kfree(con->rx_buf);
		kfree(con);
		return tmp;
		}

		hlist_add_head_rcu(&con->list, &connection_hash[r]);
		spin_unlock(&connections_lock);

		return con;
		}

		/* Loop round all connections */
		static void foreach_conn(void (conn_func)(struct connection c))
		{
		int i;
		struct hlist_node *n;
		int i, idx;
		struct connection *con;

		idx = srcu_read_lock(&connections_srcu);
		for (i = 0; i < CONN_HASH_SIZE; i++) {
		hlist_for_each_entry_safe(con, n, &connection_hash[i], list)
		hlist_for_each_entry_rcu(con, &connection_hash[i], list)
		conn_func(con);
		}
		}

		static struct connection *nodeid2con(int nodeid, gfp_t allocation)
		{
		struct connection *con;

		mutex_lock(&connections_lock);
		con = __nodeid2con(nodeid, allocation);
		mutex_unlock(&connections_lock);

		return con;
		srcu_read_unlock(&connections_srcu, idx);
		}

		static struct dlm_node_addr *find_node_addr(int nodeid)
		@@ -614,11 +601,8 @@ static void close_connection(struct connection *con, bool and_other,
		/* Will only re-enter once. */
		close_connection(con->othercon, false, true, true);
		}
		if (con->rx_page) {
		__free_page(con->rx_page);
		con->rx_page = NULL;
		}

		con->rx_leftover = 0;
		con->retries = 0;
		mutex_unlock(&con->sock_mutex);
		clear_bit(CF_CLOSING, &con->flags);
		@@ -672,16 +656,33 @@ static void dlm_tcp_shutdown(struct connection *con)
		shutdown_connection(con);
		}

		static int con_realloc_receive_buf(struct connection *con, int newlen)
		{
		unsigned char *newbuf;

		newbuf = kmalloc(newlen, GFP_NOFS);
		if (!newbuf)
		return -ENOMEM;

		/* copy any leftover from last receive */
		if (con->rx_leftover)
		memmove(newbuf, con->rx_buf, con->rx_leftover);

		/* swap to new buffer space */
		kfree(con->rx_buf);
		con->rx_buflen = newlen;
		con->rx_buf = newbuf;

		return 0;
		}

		/* Data received from remote end */
		static int receive_from_sock(struct connection *con)
		{
		int ret = 0;
		struct msghdr msg = {};
		struct kvec iov[2];
		unsigned len;
		int r;
		int call_again_soon = 0;
		int nvec;
		struct msghdr msg;
		struct kvec iov;
		int ret, buflen;

		mutex_lock(&con->sock_mutex);

		@@ -689,71 +690,55 @@ static int receive_from_sock(struct connection *con)
		ret = -EAGAIN;
		goto out_close;
		}

		if (con->nodeid == 0) {
		ret = -EINVAL;
		goto out_close;
		}

		if (con->rx_page == NULL) {
		/*
		* This doesn't need to be atomic, but I think it should
		* improve performance if it is.
		*/
		con->rx_page = alloc_page(GFP_ATOMIC);
		if (con->rx_page == NULL)
		/* realloc if we get new buffer size to read out */
		buflen = dlm_config.ci_buffer_size;
		if (con->rx_buflen != buflen && con->rx_leftover <= buflen) {
		ret = con_realloc_receive_buf(con, buflen);
		if (ret < 0)
		goto out_resched;
		cbuf_init(&con->cb, PAGE_SIZE);
		}

		/*
		* iov[0] is the bit of the circular buffer between the current end
		* point (cb.base + cb.len) and the end of the buffer.
		*/
		iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
		iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
		iov[1].iov_len = 0;
		nvec = 1;

		/*
		* iov[1] is the bit of the circular buffer between the start of the
		* buffer and the start of the currently used section (cb.base)
		/* calculate new buffer parameter regarding last receive and
		* possible leftover bytes
		*/
		if (cbuf_data(&con->cb) >= con->cb.base) {
		iov[0].iov_len = PAGE_SIZE - cbuf_data(&con->cb);
		iov[1].iov_len = con->cb.base;
		iov[1].iov_base = page_address(con->rx_page);
		nvec = 2;
		}
		len = iov[0].iov_len + iov[1].iov_len;
		iov_iter_kvec(&msg.msg_iter, READ, iov, nvec, len);
		iov.iov_base = con->rx_buf + con->rx_leftover;
		iov.iov_len = con->rx_buflen - con->rx_leftover;

		r = ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT \| MSG_NOSIGNAL);
		memset(&msg, 0, sizeof(msg));
		msg.msg_flags = MSG_DONTWAIT \| MSG_NOSIGNAL;
		ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len,
		msg.msg_flags);
		if (ret <= 0)
		goto out_close;
		else if (ret == len)
		else if (ret == iov.iov_len)
		call_again_soon = 1;

		cbuf_add(&con->cb, ret);
		ret = dlm_process_incoming_buffer(con->nodeid,
		page_address(con->rx_page),
		con->cb.base, con->cb.len,
		PAGE_SIZE);
		if (ret < 0) {
		log_print("lowcomms err %d: addr=%p, base=%u, len=%u, read=%d",
		ret, page_address(con->rx_page), con->cb.base,
		con->cb.len, r);
		cbuf_eat(&con->cb, r);
		} else {
		cbuf_eat(&con->cb, ret);
		}
		/* new buflen according readed bytes and leftover from last receive */
		buflen = ret + con->rx_leftover;
		ret = dlm_process_incoming_buffer(con->nodeid, con->rx_buf, buflen);
		if (ret < 0)
		goto out_close;

		if (cbuf_empty(&con->cb) && !call_again_soon) {
		__free_page(con->rx_page);
		con->rx_page = NULL;
		/* calculate leftover bytes from process and put it into begin of
		* the receive buffer, so next receive we have the full message
		* at the start address of the receive buffer.
		*/
		con->rx_leftover = buflen - ret;
		if (con->rx_leftover) {
		memmove(con->rx_buf, con->rx_buf + ret,
		con->rx_leftover);
		call_again_soon = true;
		}

		if (call_again_soon)
		goto out_resched;

		mutex_unlock(&con->sock_mutex);
		return 0;

		@@ -791,13 +776,11 @@ static int accept_from_sock(struct connection *con)
		int nodeid;
		struct connection *newcon;
		struct connection *addcon;
		unsigned int mark;

		mutex_lock(&connections_lock);
		if (!dlm_allow_conn) {
		mutex_unlock(&connections_lock);
		return -1;
		}
		mutex_unlock(&connections_lock);

		mutex_lock_nested(&con->sock_mutex, 0);

		@@ -830,6 +813,9 @@ static int accept_from_sock(struct connection *con)
		return -1;
		}

		dlm_comm_mark(nodeid, &mark);
		sock_set_mark(newsock->sk, mark);

		log_print("got connection from %d", nodeid);

		/* Check to see if we already have a connection to this node. This
		@@ -847,13 +833,24 @@ static int accept_from_sock(struct connection *con)
		struct connection *othercon = newcon->othercon;

		if (!othercon) {
		othercon = kmem_cache_zalloc(con_cache, GFP_NOFS);
		othercon = kzalloc(sizeof(*othercon), GFP_NOFS);
		if (!othercon) {
		log_print("failed to allocate incoming socket");
		mutex_unlock(&newcon->sock_mutex);
		result = -ENOMEM;
		goto accept_err;
		}

		othercon->rx_buflen = dlm_config.ci_buffer_size;
		othercon->rx_buf = kmalloc(othercon->rx_buflen, GFP_NOFS);
		if (!othercon->rx_buf) {
		mutex_unlock(&newcon->sock_mutex);
		kfree(othercon);
		log_print("failed to allocate incoming socket receive buffer");
		result = -ENOMEM;
		goto accept_err;
		}

		othercon->nodeid = nodeid;
		othercon->rx_action = receive_from_sock;
		mutex_init(&othercon->sock_mutex);
		@@ -975,6 +972,8 @@ static void sctp_connect_to_sock(struct connection *con)
		return;
		}

		dlm_comm_mark(con->nodeid, &mark);

		mutex_lock(&con->sock_mutex);

		/* Some odd races can cause double-connects, ignore them */
		@@ -999,11 +998,6 @@ static void sctp_connect_to_sock(struct connection *con)
		if (result < 0)
		goto socket_err;

		/* set skb mark */
		result = dlm_comm_mark(con->nodeid, &mark);
		if (result < 0)
		goto bind_err;

		sock_set_mark(sock->sk, mark);

		con->rx_action = receive_from_sock;
		@@ -1076,6 +1070,8 @@ static void tcp_connect_to_sock(struct connection *con)
		return;
		}

		dlm_comm_mark(con->nodeid, &mark);

		mutex_lock(&con->sock_mutex);
		if (con->retries++ > MAX_CONNECT_RETRIES)
		goto out;
		@@ -1090,11 +1086,6 @@ static void tcp_connect_to_sock(struct connection *con)
		if (result < 0)
		goto out_err;

		/* set skb mark */
		result = dlm_comm_mark(con->nodeid, &mark);
		if (result < 0)
		goto out_err;

		sock_set_mark(sock->sk, mark);

		memset(&saddr, 0, sizeof(saddr));
		@@ -1238,6 +1229,14 @@ static void init_local(void)
		}
		}

		static void deinit_local(void)
		{
		int i;

		for (i = 0; i < dlm_local_count; i++)
		kfree(dlm_local_addr[i]);
		}

		/* Initialise SCTP socket and bind to all interfaces */
		static int sctp_listen_for_all(void)
		{
		@@ -1546,13 +1545,6 @@ static void process_send_sockets(struct work_struct *work)
		send_to_sock(con);
		}


		/* Discard all entries on the write queues */
		static void clean_writequeues(void)
		{
		foreach_conn(clean_one_writequeue);
		}

		static void work_stop(void)
		{
		if (recv_workqueue)
		@@ -1608,26 +1600,34 @@ static void shutdown_conn(struct connection *con)
		con->shutdown_action(con);
		}

		static void connection_release(struct rcu_head *rcu)
		{
		struct connection *con = container_of(rcu, struct connection, rcu);

		kfree(con->rx_buf);
		kfree(con);
		}

		static void free_conn(struct connection *con)
		{
		close_connection(con, true, true, true);
		if (con->othercon)
		kmem_cache_free(con_cache, con->othercon);
		hlist_del(&con->list);
		kmem_cache_free(con_cache, con);
		spin_lock(&connections_lock);
		hlist_del_rcu(&con->list);
		spin_unlock(&connections_lock);
		if (con->othercon) {
		clean_one_writequeue(con->othercon);
		call_rcu(&con->othercon->rcu, connection_release);
		}
		clean_one_writequeue(con);
		call_rcu(&con->rcu, connection_release);
		}

		static void work_flush(void)
		{
		int ok;
		int ok, idx;
		int i;
		struct hlist_node *n;
		struct connection *con;

		if (recv_workqueue)
		flush_workqueue(recv_workqueue);
		if (send_workqueue)
		flush_workqueue(send_workqueue);
		do {
		ok = 1;
		foreach_conn(stop_conn);
		@@ -1635,9 +1635,10 @@ static void work_flush(void)
		flush_workqueue(recv_workqueue);
		if (send_workqueue)
		flush_workqueue(send_workqueue);
		idx = srcu_read_lock(&connections_srcu);
		for (i = 0; i < CONN_HASH_SIZE && ok; i++) {
		hlist_for_each_entry_safe(con, n,
		&connection_hash[i], list) {
		hlist_for_each_entry_rcu(con, &connection_hash[i],
		list) {
		ok &= test_bit(CF_READ_PENDING, &con->flags);
		ok &= test_bit(CF_WRITE_PENDING, &con->flags);
		if (con->othercon) {
		@@ -1648,6 +1649,7 @@ static void work_flush(void)
		}
		}
		}
		srcu_read_unlock(&connections_srcu, idx);
		} while (!ok);
		}

		@@ -1656,16 +1658,18 @@ void dlm_lowcomms_stop(void)
		/* Set all the flags to prevent any
		socket activity.
		*/
		mutex_lock(&connections_lock);
		dlm_allow_conn = 0;
		mutex_unlock(&connections_lock);

		if (recv_workqueue)
		flush_workqueue(recv_workqueue);
		if (send_workqueue)
		flush_workqueue(send_workqueue);

		foreach_conn(shutdown_conn);
		work_flush();
		clean_writequeues();
		foreach_conn(free_conn);
		work_stop();

		kmem_cache_destroy(con_cache);
		deinit_local();
		}

		int dlm_lowcomms_start(void)
		@@ -1684,16 +1688,9 @@ int dlm_lowcomms_start(void)
		goto fail;
		}

		error = -ENOMEM;
		con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
		__alignof__(struct connection), 0,
		NULL);
		if (!con_cache)
		goto fail;

		error = work_start();
		if (error)
		goto fail_destroy;
		goto fail;

		dlm_allow_conn = 1;

		@@ -1710,12 +1707,8 @@ int dlm_lowcomms_start(void)
		fail_unlisten:
		dlm_allow_conn = 0;
		con = nodeid2con(0,0);
		if (con) {
		close_connection(con, false, true, true);
		kmem_cache_free(con_cache, con);
		}
		fail_destroy:
		kmem_cache_destroy(con_cache);
		if (con)
		free_conn(con);
		fail:
		return error;
		}

fs/dlm/midcomms.c

+53 −83

Original line number	Diff line number	Diff line
		@@ -22,114 +22,84 @@
		* into packets and sends them to the comms layer.
		*/

		#include <asm/unaligned.h>

		#include "dlm_internal.h"
		#include "lowcomms.h"
		#include "config.h"
		#include "lock.h"
		#include "midcomms.h"


		static void copy_from_cb(void dst, const void base, unsigned offset,
		unsigned len, unsigned limit)
		{
		unsigned copy = len;

		if ((copy + offset) > limit)
		copy = limit - offset;
		memcpy(dst, base + offset, copy);
		len -= copy;
		if (len)
		memcpy(dst + copy, base, len);
		}

		/*
		* Called from the low-level comms layer to process a buffer of
		* commands.
		*
		* Only complete messages are processed here, any "spare" bytes from
		* the end of a buffer are saved and tacked onto the front of the next
		* message that comes in. I doubt this will happen very often but we
		* need to be able to cope with it and I don't want the task to be waiting
		* for packets to come in when there is useful work to be done.
		*/

		int dlm_process_incoming_buffer(int nodeid, const void *base,
		unsigned offset, unsigned len, unsigned limit)
		int dlm_process_incoming_buffer(int nodeid, unsigned char *buf, int len)
		{
		union {
		unsigned char __buf[DLM_INBUF_LEN];
		/* this is to force proper alignment on some arches */
		union dlm_packet p;
		} __tmp;
		union dlm_packet *p = &__tmp.p;
		int ret = 0;
		int err = 0;
		const unsigned char *ptr = buf;
		const struct dlm_header *hd;
		uint16_t msglen;
		uint32_t lockspace;

		while (len > sizeof(struct dlm_header)) {

		/* Copy just the header to check the total length. The
		message may wrap around the end of the buffer back to the
		start, so we need to use a temp buffer and copy_from_cb. */

		copy_from_cb(p, base, offset, sizeof(struct dlm_header),
		limit);
		int ret = 0;

		msglen = le16_to_cpu(p->header.h_length);
		lockspace = p->header.h_lockspace;
		while (len >= sizeof(struct dlm_header)) {
		hd = (struct dlm_header *)ptr;

		err = -EINVAL;
		if (msglen < sizeof(struct dlm_header))
		break;
		if (p->header.h_cmd == DLM_MSG) {
		if (msglen < sizeof(struct dlm_message))
		break;
		} else {
		if (msglen < sizeof(struct dlm_rcom))
		break;
		}
		err = -E2BIG;
		if (msglen > dlm_config.ci_buffer_size) {
		log_print("message size %d from %d too big, buf len %d",
		msglen, nodeid, len);
		break;
		/* no message should be more than this otherwise we
		* cannot deliver this message to upper layers
		*/
		msglen = get_unaligned_le16(&hd->h_length);
		if (msglen > DEFAULT_BUFFER_SIZE) {
		log_print("received invalid length header: %u, will abort message parsing",
		msglen);
		return -EBADMSG;
		}
		err = 0;

		/* If only part of the full message is contained in this
		buffer, then do nothing and wait for lowcomms to call
		us again later with more data. We return 0 meaning
		we've consumed none of the input buffer. */

		/* caller will take care that leftover
		* will be parsed next call with more data
		*/
		if (msglen > len)
		break;

		/* Allocate a larger temp buffer if the full message won't fit
		in the buffer on the stack (which should work for most
		ordinary messages). */
		switch (hd->h_cmd) {
		case DLM_MSG:
		if (msglen < sizeof(struct dlm_message)) {
		log_print("dlm msg too small: %u, will skip this message",
		msglen);
		goto skip;
		}

		if (msglen > sizeof(__tmp) && p == &__tmp.p) {
		p = kmalloc(dlm_config.ci_buffer_size, GFP_NOFS);
		if (p == NULL)
		return ret;
		break;
		case DLM_RCOM:
		if (msglen < sizeof(struct dlm_rcom)) {
		log_print("dlm rcom msg too small: %u, will skip this message",
		msglen);
		goto skip;
		}

		copy_from_cb(p, base, offset, msglen, limit);
		break;
		default:
		log_print("unsupported h_cmd received: %u, will skip this message",
		hd->h_cmd);
		goto skip;
		}

		BUG_ON(lockspace != p->header.h_lockspace);
		/* for aligned memory access, we just copy current message
		* to begin of the buffer which contains already parsed buffer
		* data and should provide align access for upper layers
		* because the start address of the buffer has a aligned
		* address. This memmove can be removed when the upperlayer
		* is capable of unaligned memory access.
		*/
		memmove(buf, ptr, msglen);
		dlm_receive_buffer((union dlm_packet *)buf, nodeid);

		skip:
		ret += msglen;
		offset += msglen;
		offset &= (limit - 1);
		len -= msglen;

		dlm_receive_buffer(p, nodeid);
		ptr += msglen;
		}

		if (p != &__tmp.p)
		kfree(p);

		return err ? err : ret;
		return ret;
		}

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