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unix: Wait a peer using task_st futex

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Use task_st futex notifier instead of per-socket.
The step to make file opening use the only futex.

v2: Use internal bound and listen states instead of generic

travis-ci: success for Rework file opening scheme to make it asynchronous (rev5)
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
This commit is contained in:
Kirill Tkhai
2016-12-26 17:27:36 +03:00
committed by Pavel Emelyanov
parent 08cd374dac
commit cda1115dba
1 changed files with 32 additions and 12 deletions
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44
criu/sk-unix.c
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@@ -785,19 +785,14 @@ struct unix_sk_info {
struct list_head connected; /* List of sockets, connected to me */
struct list_head node; /* To link in peer's connected list */
/*
* Futex to signal when the socket is prepared. In particular, we
* signal after bind()ing the socket if it is not in TCP_LISTEN, or
* after listen() if the socket is in TCP_LISTEN.
*/
futex_t prepared;
/*
* For DGRAM sockets with queues, we should only restore the queue
* once although it may be open by more than one tid. This is the peer
* that should do the queueing.
*/
u32 queuer;
u8 bound:1;
u8 listen:1;
};
#define USK_PAIR_MASTER 0x1
@@ -815,6 +810,26 @@ static struct unix_sk_info *find_unix_sk_by_ino(int ino)
return NULL;
}
static int wake_connected_sockets(struct unix_sk_info *ui)
{
struct fdinfo_list_entry *fle;
struct unix_sk_info *tmp;
list_for_each_entry(tmp, &ui->connected, node) {
fle = file_master(&tmp->d);
set_fds_event(fle->pid);
}
return 0;
}
static bool peer_is_not_prepared(struct unix_sk_info *peer)
{
if (peer->ue->state != TCP_LISTEN)
return (!peer->bound);
else
return (!peer->listen);
}
static int shutdown_unix_sk(int sk, struct unix_sk_info *ui)
{
int how;
@@ -887,7 +902,8 @@ static int post_open_unix_sk(struct file_desc *d, int fd)
/* Skip external sockets */
if (!list_empty(&peer->d.fd_info_head))
futex_wait_while(&peer->prepared, 0);
while (peer_is_not_prepared(peer))
wait_fds_event();
if (ui->ue->uflags & USK_INHERIT)
return 0;
@@ -1027,8 +1043,10 @@ static int bind_unix_sk(int sk, struct unix_sk_info *ui)
}
}
if (ui->ue->state != TCP_LISTEN)
futex_set_and_wake(&ui->prepared, 1);
if (ui->ue->state != TCP_LISTEN) {
ui->bound = 1;
wake_connected_sockets(ui);
}
ret = 0;
done:
@@ -1236,7 +1254,8 @@ static int open_unixsk_standalone(struct unix_sk_info *ui)
pr_perror("Can't make usk listen");
return -1;
}
futex_set_and_wake(&ui->prepared, 1);
ui->listen = 1;
wake_connected_sockets(ui);
}
out:
if (rst_file_params(sk, ui->ue->fown, ui->ue->flags))
@@ -1341,9 +1360,10 @@ static int collect_one_unixsk(void *o, ProtobufCMessage *base, struct cr_img *i)
} else
ui->name = NULL;
futex_init(&ui->prepared);
ui->queuer = 0;
ui->peer = NULL;
ui->bound = 0;
ui->listen = 0;
INIT_LIST_HEAD(&ui->connected);
INIT_LIST_HEAD(&ui->node);
ui->flags = 0;