diff options
| -rw-r--r-- | net/ipv4/ipvs/ip_vs_sync.c | 431 |
1 files changed, 172 insertions, 259 deletions
diff --git a/net/ipv4/ipvs/ip_vs_sync.c b/net/ipv4/ipvs/ip_vs_sync.c index 2d4a86f7332..45e9bd96c28 100644 --- a/net/ipv4/ipvs/ip_vs_sync.c +++ b/net/ipv4/ipvs/ip_vs_sync.c @@ -27,10 +27,12 @@ #include <linux/in.h> #include <linux/igmp.h> /* for ip_mc_join_group */ #include <linux/udp.h> +#include <linux/err.h> +#include <linux/kthread.h> +#include <linux/wait.h> #include <net/ip.h> #include <net/sock.h> -#include <asm/uaccess.h> /* for get_fs and set_fs */ #include <net/ip_vs.h> @@ -66,8 +68,8 @@ struct ip_vs_sync_conn_options { }; struct ip_vs_sync_thread_data { - struct completion *startup; - int state; + struct socket *sock; + char *buf; }; #define SIMPLE_CONN_SIZE (sizeof(struct ip_vs_sync_conn)) @@ -138,18 +140,19 @@ volatile int ip_vs_backup_syncid = 0; char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN]; char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN]; -/* multicast addr */ -static struct sockaddr_in mcast_addr; +/* sync daemon tasks */ +static struct task_struct *sync_master_thread; +static struct task_struct *sync_backup_thread; +/* multicast addr */ +static struct sockaddr_in mcast_addr = { + .sin_family = AF_INET, + .sin_port = __constant_htons(IP_VS_SYNC_PORT), + .sin_addr.s_addr = __constant_htonl(IP_VS_SYNC_GROUP), +}; -static inline void sb_queue_tail(struct ip_vs_sync_buff *sb) -{ - spin_lock(&ip_vs_sync_lock); - list_add_tail(&sb->list, &ip_vs_sync_queue); - spin_unlock(&ip_vs_sync_lock); -} -static inline struct ip_vs_sync_buff * sb_dequeue(void) +static inline struct ip_vs_sync_buff *sb_dequeue(void) { struct ip_vs_sync_buff *sb; @@ -193,6 +196,16 @@ static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb) kfree(sb); } +static inline void sb_queue_tail(struct ip_vs_sync_buff *sb) +{ + spin_lock(&ip_vs_sync_lock); + if (ip_vs_sync_state & IP_VS_STATE_MASTER) + list_add_tail(&sb->list, &ip_vs_sync_queue); + else + ip_vs_sync_buff_release(sb); + spin_unlock(&ip_vs_sync_lock); +} + /* * Get the current sync buffer if it has been created for more * than the specified time or the specified time is zero. @@ -572,14 +585,17 @@ static int bind_mcastif_addr(struct socket *sock, char *ifname) static struct socket * make_send_sock(void) { struct socket *sock; + int result; /* First create a socket */ - if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) { + result = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock); + if (result < 0) { IP_VS_ERR("Error during creation of socket; terminating\n"); - return NULL; + return ERR_PTR(result); } - if (set_mcast_if(sock->sk, ip_vs_master_mcast_ifn) < 0) { + result = set_mcast_if(sock->sk, ip_vs_master_mcast_ifn); + if (result < 0) { IP_VS_ERR("Error setting outbound mcast interface\n"); goto error; } @@ -587,14 +603,15 @@ static struct socket * make_send_sock(void) set_mcast_loop(sock->sk, 0); set_mcast_ttl(sock->sk, 1); - if (bind_mcastif_addr(sock, ip_vs_master_mcast_ifn) < 0) { + result = bind_mcastif_addr(sock, ip_vs_master_mcast_ifn); + if (result < 0) { IP_VS_ERR("Error binding address of the mcast interface\n"); goto error; } - if (sock->ops->connect(sock, - (struct sockaddr*)&mcast_addr, - sizeof(struct sockaddr), 0) < 0) { + result = sock->ops->connect(sock, (struct sockaddr *) &mcast_addr, + sizeof(struct sockaddr), 0); + if (result < 0) { IP_VS_ERR("Error connecting to the multicast addr\n"); goto error; } @@ -603,7 +620,7 @@ static struct socket * make_send_sock(void) error: sock_release(sock); - return NULL; + return ERR_PTR(result); } @@ -613,27 +630,30 @@ static struct socket * make_send_sock(void) static struct socket * make_receive_sock(void) { struct socket *sock; + int result; /* First create a socket */ - if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) { + result = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock); + if (result < 0) { IP_VS_ERR("Error during creation of socket; terminating\n"); - return NULL; + return ERR_PTR(result); } /* it is equivalent to the REUSEADDR option in user-space */ sock->sk->sk_reuse = 1; - if (sock->ops->bind(sock, - (struct sockaddr*)&mcast_addr, - sizeof(struct sockaddr)) < 0) { + result = sock->ops->bind(sock, (struct sockaddr *) &mcast_addr, + sizeof(struct sockaddr)); + if (result < 0) { IP_VS_ERR("Error binding to the multicast addr\n"); goto error; } /* join the multicast group */ - if (join_mcast_group(sock->sk, - (struct in_addr*)&mcast_addr.sin_addr, - ip_vs_backup_mcast_ifn) < 0) { + result = join_mcast_group(sock->sk, + (struct in_addr *) &mcast_addr.sin_addr, + ip_vs_backup_mcast_ifn); + if (result < 0) { IP_VS_ERR("Error joining to the multicast group\n"); goto error; } @@ -642,7 +662,7 @@ static struct socket * make_receive_sock(void) error: sock_release(sock); - return NULL; + return ERR_PTR(result); } @@ -700,44 +720,29 @@ ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen) } -static DECLARE_WAIT_QUEUE_HEAD(sync_wait); -static pid_t sync_master_pid = 0; -static pid_t sync_backup_pid = 0; - -static DECLARE_WAIT_QUEUE_HEAD(stop_sync_wait); -static int stop_master_sync = 0; -static int stop_backup_sync = 0; - -static void sync_master_loop(void) +static int sync_thread_master(void *data) { - struct socket *sock; + struct ip_vs_sync_thread_data *tinfo = data; struct ip_vs_sync_buff *sb; - /* create the sending multicast socket */ - sock = make_send_sock(); - if (!sock) - return; - IP_VS_INFO("sync thread started: state = MASTER, mcast_ifn = %s, " "syncid = %d\n", ip_vs_master_mcast_ifn, ip_vs_master_syncid); - for (;;) { - while ((sb=sb_dequeue())) { - ip_vs_send_sync_msg(sock, sb->mesg); + while (!kthread_should_stop()) { + while ((sb = sb_dequeue())) { + ip_vs_send_sync_msg(tinfo->sock, sb->mesg); ip_vs_sync_buff_release(sb); } /* check if entries stay in curr_sb for 2 seconds */ - if ((sb = get_curr_sync_buff(2*HZ))) { - ip_vs_send_sync_msg(sock, sb->mesg); + sb = get_curr_sync_buff(2 * HZ); + if (sb) { + ip_vs_send_sync_msg(tinfo->sock, sb->mesg); ip_vs_sync_buff_release(sb); } - if (stop_master_sync) - break; - - msleep_interruptible(1000); + schedule_timeout_interruptible(HZ); } /* clean up the sync_buff queue */ @@ -751,267 +756,175 @@ static void sync_master_loop(void) } /* release the sending multicast socket */ - sock_release(sock); + sock_release(tinfo->sock); + kfree(tinfo); + + return 0; } -static void sync_backup_loop(void) +static int sync_thread_backup(void *data) { - struct socket *sock; - char *buf; + struct ip_vs_sync_thread_data *tinfo = data; int len; - if (!(buf = kmalloc(sync_recv_mesg_maxlen, GFP_ATOMIC))) { - IP_VS_ERR("sync_backup_loop: kmalloc error\n"); - return; - } - - /* create the receiving multicast socket */ - sock = make_receive_sock(); - if (!sock) - goto out; - IP_VS_INFO("sync thread started: state = BACKUP, mcast_ifn = %s, " "syncid = %d\n", ip_vs_backup_mcast_ifn, ip_vs_backup_syncid); - for (;;) { - /* do you have data now? */ - while (!skb_queue_empty(&(sock->sk->sk_receive_queue))) { - if ((len = - ip_vs_receive(sock, buf, - sync_recv_mesg_maxlen)) <= 0) { + while (!kthread_should_stop()) { + wait_event_interruptible(*tinfo->sock->sk->sk_sleep, + !skb_queue_empty(&tinfo->sock->sk->sk_receive_queue) + || kthread_should_stop()); + + /* do we have data now? */ + while (!skb_queue_empty(&(tinfo->sock->sk->sk_receive_queue))) { + len = ip_vs_receive(tinfo->sock, tinfo->buf, + sync_recv_mesg_maxlen); + if (len <= 0) { IP_VS_ERR("receiving message error\n"); break; } - /* disable bottom half, because it accessed the data + + /* disable bottom half, because it accesses the data shared by softirq while getting/creating conns */ local_bh_disable(); - ip_vs_process_message(buf, len); + ip_vs_process_message(tinfo->buf, len); local_bh_enable(); } - - if (stop_backup_sync) - break; - - msleep_interruptible(1000); } /* release the sending multicast socket */ - sock_release(sock); + sock_release(tinfo->sock); + kfree(tinfo->buf); + kfree(tinfo); - out: - kfree(buf); + return 0; } -static void set_sync_pid(int sync_state, pid_t sync_pid) -{ - if (sync_state == IP_VS_STATE_MASTER) - sync_master_pid = sync_pid; - else if (sync_state == IP_VS_STATE_BACKUP) - sync_backup_pid = sync_pid; -} - -static void set_stop_sync(int sync_state, int set) +int start_sync_thread(int state, char *mcast_ifn, __u8 syncid) { - if (sync_state == IP_VS_STATE_MASTER) - stop_master_sync = set; - else if (sync_state == IP_VS_STATE_BACKUP) - stop_backup_sync = set; - else { - stop_master_sync = set; - stop_backup_sync = set; - } -} + struct ip_vs_sync_thread_data *tinfo; + struct task_struct **realtask, *task; + struct socket *sock; + char *name, *buf = NULL; + int (*threadfn)(void *data); + int result = -ENOMEM; -static int sync_thread(void *startup) -{ - DECLARE_WAITQUEUE(wait, current); - mm_segment_t oldmm; - int state; - const char *name; - struct ip_vs_sync_thread_data *tinfo = startup; + IP_VS_DBG(7, "%s: pid %d\n", __func__, task_pid_nr(current)); + IP_VS_DBG(7, "Each ip_vs_sync_conn entry needs %Zd bytes\n", + sizeof(struct ip_vs_sync_conn)); - /* increase the module use count */ - ip_vs_use_count_inc(); + if (state == IP_VS_STATE_MASTER) { + if (sync_master_thread) + return -EEXIST; - if (ip_vs_sync_state & IP_VS_STATE_MASTER && !sync_master_pid) { - state = IP_VS_STATE_MASTER; + strlcpy(ip_vs_master_mcast_ifn, mcast_ifn, + sizeof(ip_vs_master_mcast_ifn)); + ip_vs_master_syncid = syncid; + realtask = &sync_master_thread; name = "ipvs_syncmaster"; - } else if (ip_vs_sync_state & IP_VS_STATE_BACKUP && !sync_backup_pid) { - state = IP_VS_STATE_BACKUP; + threadfn = sync_thread_master; + sock = make_send_sock(); + } else if (state == IP_VS_STATE_BACKUP) { + if (sync_backup_thread) + return -EEXIST; + + strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn, + sizeof(ip_vs_backup_mcast_ifn)); + ip_vs_backup_syncid = syncid; + realtask = &sync_backup_thread; name = "ipvs_syncbackup"; + threadfn = sync_thread_backup; + sock = make_receive_sock(); } else { - IP_VS_BUG(); - ip_vs_use_count_dec(); return -EINVAL; } - daemonize(name); - - oldmm = get_fs(); - set_fs(KERNEL_DS); - - /* Block all signals */ - spin_lock_irq(¤t->sighand->siglock); - siginitsetinv(¤t->blocked, 0); - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); + if (IS_ERR(sock)) { + result = PTR_ERR(sock); + goto out; + } - /* set the maximum length of sync message */ set_sync_mesg_maxlen(state); + if (state == IP_VS_STATE_BACKUP) { + buf = kmalloc(sync_recv_mesg_maxlen, GFP_KERNEL); + if (!buf) + goto outsocket; + } - /* set up multicast address */ - mcast_addr.sin_family = AF_INET; - mcast_addr.sin_port = htons(IP_VS_SYNC_PORT); - mcast_addr.sin_addr.s_addr = htonl(IP_VS_SYNC_GROUP); - - add_wait_queue(&sync_wait, &wait); - - set_sync_pid(state, task_pid_nr(current)); - complete(tinfo->startup); - - /* - * once we call the completion queue above, we should - * null out that reference, since its allocated on the - * stack of the creating kernel thread - */ - tinfo->startup = NULL; - - /* processing master/backup loop here */ - if (state == IP_VS_STATE_MASTER) - sync_master_loop(); - else if (state == IP_VS_STATE_BACKUP) - sync_backup_loop(); - else IP_VS_BUG(); - - remove_wait_queue(&sync_wait, &wait); - - /* thread exits */ - - /* - * If we weren't explicitly stopped, then we - * exited in error, and should undo our state - */ - if ((!stop_master_sync) && (!stop_backup_sync)) - ip_vs_sync_state -= tinfo->state; + tinfo = kmalloc(sizeof(*tinfo), GFP_KERNEL); + if (!tinfo) + goto outbuf; - set_sync_pid(state, 0); - IP_VS_INFO("sync thread stopped!\n"); + tinfo->sock = sock; + tinfo->buf = buf; - set_fs(oldmm); + task = kthread_run(threadfn, tinfo, name); + if (IS_ERR(task)) { + result = PTR_ERR(task); + goto outtinfo; + } - /* decrease the module use count */ - ip_vs_use_count_dec(); + /* mark as active */ + *realtask = task; + ip_vs_sync_state |= state; - set_stop_sync(state, 0); - wake_up(&stop_sync_wait); + /* increase the module use count */ + ip_vs_use_count_inc(); - /* - * we need to free the structure that was allocated - * for us in start_sync_thread - */ - kfree(tinfo); return 0; -} - - -static int fork_sync_thread(void *startup) -{ - pid_t pid; - - /* fork the sync thread here, then the parent process of the - sync thread is the init process after this thread exits. */ - repeat: - if ((pid = kernel_thread(sync_thread, startup, 0)) < 0) { - IP_VS_ERR("could not create sync_thread due to %d... " - "retrying.\n", pid); - msleep_interruptible(1000); - goto repeat; - } - return 0; +outtinfo: + kfree(tinfo); +outbuf: + kfree(buf); +outsocket: + sock_release(sock); +out: + return result; } -int start_sync_thread(int state, char *mcast_ifn, __u8 syncid) +int stop_sync_thread(int state) { - DECLARE_COMPLETION_ONSTACK(startup); - pid_t pid; - struct ip_vs_sync_thread_data *tinfo; - - if ((state == IP_VS_STATE_MASTER && sync_master_pid) || - (state == IP_VS_STATE_BACKUP && sync_backup_pid)) - return -EEXIST; - - /* - * Note that tinfo will be freed in sync_thread on exit - */ - tinfo = kmalloc(sizeof(struct ip_vs_sync_thread_data), GFP_KERNEL); - if (!tinfo) - return -ENOMEM; - IP_VS_DBG(7, "%s: pid %d\n", __func__, task_pid_nr(current)); - IP_VS_DBG(7, "Each ip_vs_sync_conn entry need %Zd bytes\n", - sizeof(struct ip_vs_sync_conn)); - ip_vs_sync_state |= state; if (state == IP_VS_STATE_MASTER) { - strlcpy(ip_vs_master_mcast_ifn, mcast_ifn, - sizeof(ip_vs_master_mcast_ifn)); - ip_vs_master_syncid = syncid; - } else { - strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn, - sizeof(ip_vs_backup_mcast_ifn)); - ip_vs_backup_syncid = syncid; - } - - tinfo->state = state; - tinfo->startup = &startup; - - repeat: - if ((pid = kernel_thread(fork_sync_thread, tinfo, 0)) < 0) { - IP_VS_ERR("could not create fork_sync_thread due to %d... " - "retrying.\n", pid); - msleep_interruptible(1000); - goto repeat; - } - - wait_for_completion(&startup); - - return 0; -} + if (!sync_master_thread) + return -ESRCH; + IP_VS_INFO("stopping master sync thread %d ...\n", + task_pid_nr(sync_master_thread)); -int stop_sync_thread(int state) -{ - DECLARE_WAITQUEUE(wait, current); + /* + * The lock synchronizes with sb_queue_tail(), so that we don't + * add sync buffers to the queue, when we are already in + * progress of stopping the master sync daemon. + */ - if ((state == IP_VS_STATE_MASTER && !sync_master_pid) || - (state == IP_VS_STATE_BACKUP && !sync_backup_pid)) - return -ESRCH; + spin_lock(&ip_vs_sync_lock); + ip_vs_sync_state &= ~IP_VS_STATE_MASTER; + spin_unlock(&ip_vs_sync_lock); + kthread_stop(sync_master_thread); + sync_master_thread = NULL; + } else if (state == IP_VS_STATE_BACKUP) { + if (!sync_backup_thread) + return -ESRCH; + + IP_VS_INFO("stopping backup sync thread %d ...\n", + task_pid_nr(sync_backup_thread)); + + ip_vs_sync_state &= ~IP_VS_STATE_BACKUP; + kthread_stop(sync_backup_thread); + sync_backup_thread = NULL; + } else { + return -EINVAL; + } - IP_VS_DBG(7, "%s: pid %d\n", __func__, task_pid_nr(current)); - IP_VS_INFO("stopping sync thread %d ...\n", - (state == IP_VS_STATE_MASTER) ? - sync_master_pid : sync_backup_pid); - - __set_current_state(TASK_UNINTERRUPTIBLE); - add_wait_queue(&stop_sync_wait, &wait); - set_stop_sync(state, 1); - ip_vs_sync_state -= state; - wake_up(&sync_wait); - schedule(); - __set_current_state(TASK_RUNNING); - remove_wait_queue(&stop_sync_wait, &wait); - - /* Note: no need to reap the sync thread, because its parent - process is the init process */ - - if ((state == IP_VS_STATE_MASTER && stop_master_sync) || - (state == IP_VS_STATE_BACKUP && stop_backup_sync)) - IP_VS_BUG(); + /* decrease the module use count */ + ip_vs_use_count_dec(); return 0; } |