linux/include/net/af_unix.h
dann frazier 5f23b73496 net: Fix soft lockups/OOM issues w/ unix garbage collector
This is an implementation of David Miller's suggested fix in:
  https://bugzilla.redhat.com/show_bug.cgi?id=470201

It has been updated to use wait_event() instead of
wait_event_interruptible().

Paraphrasing the description from the above report, it makes sendmsg()
block while UNIX garbage collection is in progress. This avoids a
situation where child processes continue to queue new FDs over a
AF_UNIX socket to a parent which is in the exit path and running
garbage collection on these FDs. This contention can result in soft
lockups and oom-killing of unrelated processes.

Signed-off-by: dann frazier <dannf@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-26 15:32:27 -08:00

71 lines
1.8 KiB
C

#ifndef __LINUX_NET_AFUNIX_H
#define __LINUX_NET_AFUNIX_H
#include <linux/socket.h>
#include <linux/un.h>
#include <linux/mutex.h>
#include <net/sock.h>
extern void unix_inflight(struct file *fp);
extern void unix_notinflight(struct file *fp);
extern void unix_gc(void);
extern void wait_for_unix_gc(void);
#define UNIX_HASH_SIZE 256
extern unsigned int unix_tot_inflight;
struct unix_address {
atomic_t refcnt;
int len;
unsigned hash;
struct sockaddr_un name[0];
};
struct unix_skb_parms {
struct ucred creds; /* Skb credentials */
struct scm_fp_list *fp; /* Passed files */
#ifdef CONFIG_SECURITY_NETWORK
u32 secid; /* Security ID */
#endif
};
#define UNIXCB(skb) (*(struct unix_skb_parms*)&((skb)->cb))
#define UNIXCREDS(skb) (&UNIXCB((skb)).creds)
#define UNIXSID(skb) (&UNIXCB((skb)).secid)
#define unix_state_lock(s) spin_lock(&unix_sk(s)->lock)
#define unix_state_unlock(s) spin_unlock(&unix_sk(s)->lock)
#define unix_state_lock_nested(s) \
spin_lock_nested(&unix_sk(s)->lock, \
SINGLE_DEPTH_NESTING)
#ifdef __KERNEL__
/* The AF_UNIX socket */
struct unix_sock {
/* WARNING: sk has to be the first member */
struct sock sk;
struct unix_address *addr;
struct dentry *dentry;
struct vfsmount *mnt;
struct mutex readlock;
struct sock *peer;
struct sock *other;
struct list_head link;
atomic_long_t inflight;
spinlock_t lock;
unsigned int gc_candidate : 1;
unsigned int gc_maybe_cycle : 1;
wait_queue_head_t peer_wait;
};
#define unix_sk(__sk) ((struct unix_sock *)__sk)
#ifdef CONFIG_SYSCTL
extern int unix_sysctl_register(struct net *net);
extern void unix_sysctl_unregister(struct net *net);
#else
static inline int unix_sysctl_register(struct net *net) { return 0; }
static inline void unix_sysctl_unregister(struct net *net) {}
#endif
#endif
#endif