在 2022/4/27 15:15, wanghai (M) 写道:
在 2022/4/27 2:51, Trond Myklebust 写道:
On Tue, 2022-04-26 at 21:20 +0800, Wang Hai wrote:
If the connection to a local endpoint in xs_local_setup_socket()
fails,
fput() is missing in the error path, which will result in a socket
leak.
It can be reproduced in simple script below.
while true
do
systemctl stop rpcbind.service
systemctl stop rpc-statd.service
systemctl stop nfs-server.service
systemctl restart rpcbind.service
systemctl restart rpc-statd.service
systemctl restart nfs-server.service
done
When executing the script, you can observe that the
"cat /proc/net/unix | wc -l" count keeps growing.
Add the missing fput(), and restore transport to old socket.
Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
---
net/sunrpc/xprtsock.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 0f39e08ee580..7219c545385e 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1819,6 +1819,9 @@ static int xs_local_finish_connecting(struct
rpc_xprt *xprt,
{
struct sock_xprt *transport = container_of(xprt, struct
sock_xprt,
xprt);
+ struct socket *trans_sock = NULL;
+ struct sock *trans_inet = NULL;
+ int ret;
if (!transport->inet) {
struct sock *sk = sock->sk;
@@ -1835,6 +1838,9 @@ static int xs_local_finish_connecting(struct
rpc_xprt *xprt,
xprt_clear_connected(xprt);
+ trans_sock = transport->sock;
+ trans_inet = transport->inet;
+
Both values are NULL here
Got it, thanks
/* Reset to new socket */
transport->sock = sock;
transport->inet = sk;
@@ -1844,7 +1850,14 @@ static int xs_local_finish_connecting(struct
rpc_xprt *xprt,
xs_stream_start_connect(transport);
- return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
+ ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
+ /* Restore to old socket */
+ if (ret && trans_inet) {
+ transport->sock = trans_sock;
+ transport->inet = trans_inet;
+ }
+
+ return ret;
}
/**
@@ -1887,7 +1900,7 @@ static int xs_local_setup_socket(struct
sock_xprt *transport)
xprt->stat.connect_time += (long)jiffies -
xprt->stat.connect_start;
xprt_set_connected(xprt);
- break;
+ goto out;
case -ENOBUFS:
break;
case -ENOENT:
@@ -1904,6 +1917,9 @@ static int xs_local_setup_socket(struct
sock_xprt *transport)
xprt-
address_strings[RPC_DISPLAY_ADDR]);
}
+ transport->file = NULL;
+ fput(filp);
Please just call xprt_force_disconnect() so that this can be cleaned up
from a safe context.
Hi, Trond
Thank you for your advice, I tried this, but it doesn't seem to
work and an error is reported. I'll analyze why this happens
Hi, Trond.
If I call xprt_force_disconnect(), it reports the following error,
I spent a long time but couldn't find the cause of the error. If I
call xs_close(), it works, is it possible to call xs_close() here?
[ 107.147326][ T7128]
======================================================
[ 107.147329][ T7128] WARNING: possible circular locking dependency
detected
[ 107.147333][ T7128] 5.17.0+ #10 Not tainted
[ 107.147340][ T7128]
------------------------------------------------------
[ 107.147343][ T7128] rpc.nfsd/7128 is trying to acquire lock:
[ 107.147349][ T7128] ffffffff850f4960 (console_owner){..-.}-{0:0}, at:
console_unlock+0x1d7/0x790
[ 107.147384][ T7128]
[ 107.147384][ T7128] but task is already holding lock:
[ 107.147387][ T7128] ffff88824010b418 (&pool->lock/1){-.-.}-{2:2}, at:
__queue_work+0x450/0x810
[ 107.147420][ T7128]
[ 107.147420][ T7128] which lock already depends on the new lock.
[ 107.147420][ T7128]
[ 107.147423][ T7128]
[ 107.147423][ T7128] the existing dependency chain (in reverse order) is:
[ 107.147426][ T7128]
[ 107.147426][ T7128] -> #2 (&pool->lock/1){-.-.}-{2:2}:
[ 107.147444][ T7128] _raw_spin_lock+0x32/0x50
[ 107.147482][ T7128] __queue_work+0x131/0x810
[ 107.147496][ T7128] queue_work_on+0x88/0x90
[ 107.147509][ T7128] tty_flip_buffer_push+0x34/0x40
[ 107.147525][ T7128] serial8250_rx_chars+0x73/0x80
[ 107.147537][ T7128] serial8250_handle_irq.part.21+0x124/0x160
[ 107.147552][ T7128] serial8250_default_handle_irq+0x79/0x90
[ 107.147566][ T7128] serial8250_interrupt+0x73/0xd0
[ 107.147581][ T7128] __handle_irq_event_percpu+0x54/0x3c0
[ 107.147597][ T7128] handle_irq_event_percpu+0x1c/0x50
[ 107.147611][ T7128] handle_irq_event+0x3e/0x60
[ 107.147624][ T7128] handle_edge_irq+0xc3/0x250
[ 107.147636][ T7128] __common_interrupt+0x71/0x140
[ 107.147649][ T7128] common_interrupt+0xbc/0xe0
[ 107.147664][ T7128] asm_common_interrupt+0x1e/0x40
[ 107.147677][ T7128] default_idle+0x14/0x20
[ 107.147687][ T7128] arch_cpu_idle+0xf/0x20
[ 107.147698][ T7128] default_idle_call+0x6f/0x230
[ 107.147709][ T7128] do_idle+0x1c4/0x250
[ 107.147722][ T7128] cpu_startup_entry+0x1d/0x20
[ 107.147736][ T7128] start_secondary+0xe6/0xf0
[ 107.147751][ T7128] secondary_startup_64_no_verify+0xc3/0xcb
[ 107.147767][ T7128]
[ 107.147767][ T7128] -> #1 (&port_lock_key){-.-.}-{2:2}:
[ 107.147783][ T7128] _raw_spin_lock_irqsave+0x42/0x60
[ 107.147795][ T7128] serial8250_console_write+0x31b/0x380
[ 107.147808][ T7128] univ8250_console_write+0x3a/0x50
[ 107.147820][ T7128] console_unlock+0x51d/0x790
[ 107.147832][ T7128] vprintk_emit+0x252/0x320
[ 107.147844][ T7128] vprintk_default+0x2b/0x30
[ 107.147856][ T7128] vprintk+0x71/0x80
[ 107.147868][ T7128] _printk+0x63/0x82
[ 107.147879][ T7128] register_console+0x233/0x400
[ 107.147892][ T7128] univ8250_console_init+0x35/0x3f
[ 107.147907][ T7128] console_init+0x233/0x345
[ 107.147920][ T7128] start_kernel+0xa70/0xbf8
[ 107.147931][ T7128] x86_64_start_reservations+0x2a/0x2c
[ 107.147947][ T7128] x86_64_start_kernel+0x90/0x95
[ 107.147961][ T7128] secondary_startup_64_no_verify+0xc3/0xcb
[ 107.147975][ T7128]
[ 107.147975][ T7128] -> #0 (console_owner){..-.}-{0:0}:
[ 107.147990][ T7128] __lock_acquire+0x1552/0x1a30
[ 107.148002][ T7128] lock_acquire+0x25e/0x2f0
[ 107.148014][ T7128] console_unlock+0x22e/0x790
[ 107.148026][ T7128] vprintk_emit+0x252/0x320
[ 107.148038][ T7128] vprintk_default+0x2b/0x30
[ 107.148050][ T7128] vprintk+0x71/0x80
[ 107.148061][ T7128] _printk+0x63/0x82
[ 107.148072][ T7128] report_bug+0x1a6/0x1c0
[ 107.148085][ T7128] handle_bug+0x43/0x70
[ 107.148098][ T7128] exc_invalid_op+0x18/0x70
[ 107.148111][ T7128] asm_exc_invalid_op+0x12/0x20
[ 107.148123][ T7128] __queue_work+0x72a/0x810
[ 107.148136][ T7128] queue_work_on+0x88/0x90
[ 107.148149][ T7128] xprt_schedule_autoclose_locked+0x7a/0xb0
[ 107.148162][ T7128] xprt_force_disconnect+0x53/0x150
[ 107.148173][ T7128] xs_local_setup_socket+0x2b2/0x480
[ 107.148188][ T7128] xs_setup_local+0x24b/0x280
[ 107.148200][ T7128] xprt_create_transport+0xb0/0x340
[ 107.148212][ T7128] rpc_create+0x104/0x2b0
[ 107.148226][ T7128] rpcb_create_local_unix+0xb2/0x2c0
[ 107.148242][ T7128] rpcb_create_local+0x79/0x90
[ 107.148256][ T7128] svc_bind+0x92/0xd0
[ 107.148267][ T7128] nfsd_create_serv+0x131/0x3a0
[ 107.148280][ T7128] write_ports+0x2d4/0x8d0
[ 107.148292][ T7128] nfsctl_transaction_write+0x70/0xb0
[ 107.148305][ T7128] vfs_write+0x11d/0x4b0
[ 107.148319][ T7128] ksys_write+0xe0/0x130
[ 107.148330][ T7128] __x64_sys_write+0x23/0x30
[ 107.148343][ T7128] do_syscall_64+0x34/0xb0
[ 107.148356][ T7128] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 107.148369][ T7128]
[ 107.148369][ T7128] other info that might help us debug this:
[ 107.148369][ T7128]
[ 107.148372][ T7128] Chain exists of:
[ 107.148372][ T7128] console_owner --> &port_lock_key --> &pool->lock/1
[ 107.148372][ T7128]
[ 107.148392][ T7128] Possible unsafe locking scenario:
[ 107.148392][ T7128]
[ 107.148395][ T7128] CPU0 CPU1
[ 107.148397][ T7128] ---- ----
[ 107.148399][ T7128] lock(&pool->lock/1);
[ 107.148409][ T7128] lock(&port_lock_key);
[ 107.148416][ T7128] lock(&pool->lock/1);
[ 107.148426][ T7128] lock(console_owner);
[ 107.148432][ T7128]
[ 107.148432][ T7128] *** DEADLOCK ***
[ 107.148432][ T7128]
[ 107.148434][ T7128] 7 locks held by rpc.nfsd/7128:
[ 107.148442][ T7128] #0: ffff8882480a4460
(sb_writers#12){.+.+}-{0:0}, at: ksys_write+0xe0/0x130
[ 107.148474][ T7128] #1: ffffffff8526ee88 (nfsd_mutex){+.+.}-{3:3},
at: write_ports+0x41/0x8d0
[ 107.148503][ T7128] #2: ffffffff854cdc88
(rpcb_create_local_mutex){+.+.}-{3:3}, at: rpcb_create_local+0x43/0x90
[ 107.148534][ T7128] #3: ffff888243f14740
(&xprt->transport_lock){+.+.}-{2:2}, at: xprt_force_disconnect+0x4b/0x150
[ 107.148562][ T7128] #4: ffffffff851d7a60
(rcu_read_lock){....}-{1:2}, at: __queue_work+0x5a/0x810
[ 107.148592][ T7128] #5: ffff88824010b418
(&pool->lock/1){-.-.}-{2:2}, at: __queue_work+0x450/0x810
[ 107.148625][ T7128] #6: ffffffff851d4d60 (console_lock){+.+.}-{0:0},
at: vprintk_emit+0x114/0x320
[ 107.148653][ T7128]
[ 107.148653][ T7128] stack backtrace:
[ 107.148656][ T7128] CPU: 3 PID: 7128 Comm: rpc.nfsd Not tainted
5.17.0+ #10
[ 107.148670][ T7128] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 107.148677][ T7128] Call Trace:
[ 107.148680][ T7128] <TASK>
[ 107.148685][ T7128] dump_stack_lvl+0x6c/0x8b
[ 107.148702][ T7128] dump_stack+0x15/0x17
[ 107.148715][ T7128] print_circular_bug.isra.46+0x261/0x2c0
[ 107.148767][ T7128] check_noncircular+0x105/0x120
[ 107.148787][ T7128] __lock_acquire+0x1552/0x1a30
[ 107.148800][ T7128] ? __lock_acquire+0x1552/0x1a30
[ 107.148820][ T7128] lock_acquire+0x25e/0x2f0
[ 107.148833][ T7128] ? console_unlock+0x1d7/0x790
[ 107.148848][ T7128] ? lock_release+0x204/0x2c0
[ 107.148865][ T7128] console_unlock+0x22e/0x790
[ 107.148878][ T7128] ? console_unlock+0x1d7/0x790
[ 107.148900][ T7128] vprintk_emit+0x252/0x320
[ 107.148916][ T7128] vprintk_default+0x2b/0x30
[ 107.148931][ T7128] vprintk+0x71/0x80
[ 107.148945][ T7128] _printk+0x63/0x82
[ 107.148959][ T7128] ? report_bug+0x19a/0x1c0
[ 107.148974][ T7128] ? __queue_work+0x72a/0x810
[ 107.148988][ T7128] report_bug+0x1a6/0x1c0
[ 107.149004][ T7128] handle_bug+0x43/0x70
[ 107.149019][ T7128] exc_invalid_op+0x18/0x70
[ 107.149034][ T7128] asm_exc_invalid_op+0x12/0x20
[ 107.149047][ T7128] RIP: 0010:__queue_work+0x72a/0x810
[ 107.149063][ T7128] Code: 48 c7 c7 78 7b b8 84 c6 05 b1 f4 39 04 01
e8 ad 65 05 00 e9 7f fe ff ff e8 33 94 11 00 4c 8b 33 e9 ff f9 ff ff e8
26 94 11 00 <0f> 0b e9 d2 fa ff ff e8 1a 94 11 00 4c 8d 7b 68 41 83 cc
02 e9 aa
[ 107.149077][ T7128] RSP: 0018:ffffc900042efa88 EFLAGS: 00010093
[ 107.149087][ T7128] RAX: 0000000000000000 RBX: ffff88824013c100 RCX:
0000000000000000
[ 107.149096][ T7128] RDX: ffff888111b15140 RSI: ffffffff8119be6a RDI:
ffffffff84c6fd9e
[ 107.149104][ T7128] RBP: ffffc900042efac8 R08: 0000000000000001 R09:
0000000000000000
[ 107.149112][ T7128] R10: 0000000000000002 R11: 000000000000f2ce R12:
0000000000000000
[ 107.149120][ T7128] R13: ffff888243f14668 R14: ffff888237c2d440 R15:
ffff888240ffc000
[ 107.149134][ T7128] ? __queue_work+0x72a/0x810
[ 107.149151][ T7128] ? __queue_work+0x72a/0x810
[ 107.149169][ T7128] queue_work_on+0x88/0x90
[ 107.149185][ T7128] xprt_schedule_autoclose_locked+0x7a/0xb0
[ 107.149200][ T7128] xprt_force_disconnect+0x53/0x150
[ 107.149213][ T7128] xs_local_setup_socket+0x2b2/0x480
[ 107.149230][ T7128] xs_setup_local+0x24b/0x280
[ 107.149245][ T7128] xprt_create_transport+0xb0/0x340
[ 107.149259][ T7128] rpc_create+0x104/0x2b0
[ 107.149278][ T7128] ? __this_cpu_preempt_check+0x1c/0x20
[ 107.149293][ T7128] ? lock_is_held_type+0xde/0x130
[ 107.149307][ T7128] rpcb_create_local_unix+0xb2/0x2c0
[ 107.149332][ T7128] rpcb_create_local+0x79/0x90
[ 107.149348][ T7128] svc_bind+0x92/0xd0
[ 107.149363][ T7128] nfsd_create_serv+0x131/0x3a0
[ 107.149378][ T7128] write_ports+0x2d4/0x8d0
[ 107.149392][ T7128] ? _copy_from_user+0x8b/0xe0
[ 107.149411][ T7128] ? nfsd_init_net+0x2d0/0x2d0
[ 107.149425][ T7128] nfsctl_transaction_write+0x70/0xb0
[ 107.149439][ T7128] ? export_features_show+0x30/0x30
[ 107.149454][ T7128] vfs_write+0x11d/0x4b0
[ 107.149470][ T7128] ksys_write+0xe0/0x130
[ 107.149486][ T7128] __x64_sys_write+0x23/0x30
[ 107.149501][ T7128] do_syscall_64+0x34/0xb0
[ 107.149515][ T7128] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 107.149530][ T7128] RIP: 0033:0x7feb99b00130
[ 107.149540][ T7128] Code: 73 01 c3 48 8b 0d 58 ed 2c 00 f7 d8 64 89
01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 45 2d 00 00 75 10 b8 01 00
00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 3e f3 01 00 48
89 04 24
[ 107.149553][ T7128] RSP: 002b:00007ffc849b68e8 EFLAGS: 00000246
ORIG_RAX: 0000000000000001
[ 107.149565][ T7128] RAX: ffffffffffffffda RBX: 0000000000000000 RCX:
00007feb99b00130
[ 107.149574][ T7128] RDX: 0000000000000002 RSI: 000055d532e09620 RDI:
0000000000000003
[ 107.149581][ T7128] RBP: 0000000000000003 R08: 000055d532c06704 R09:
0000000000000000
[ 107.149589][ T7128] R10: 0000000000000000 R11: 0000000000000246 R12:
0000000000000004
[ 107.149597][ T7128] R13: 000055d532e09620 R14: 000055d532c066bf R15:
000055d533474730
[ 107.149614][ T7128] </TASK>
[ 107.283659][ T7128] WARNING: CPU: 3 PID: 7128 at
kernel/workqueue.c:1499 __queue_work+0x72a/0x810
[ 107.283659][ T7128] Modules linked in:
[ 107.283659][ T7128] CPU: 3 PID: 7128 Comm: rpc.nfsd Not tainted
5.17.0+ #10
[ 107.283659][ T7128] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 107.283659][ T7128] RIP: 0010:__queue_work+0x72a/0x810
[ 107.283659][ T7128] Code: 48 c7 c7 78 7b b8 84 c6 05 b1 f4 39 04 01
e8 ad 65 05 00 e9 7f fe ff ff e8 33 94 11 00 4c 8b 33 e9 ff f9 ff ff e8
26 94 11 00 <0f> 0b e9 d2 fa ff ff e8 1a 94 11 00 4c 8d 7b 68 41 83 cc
02 e9 aa
[ 107.283659][ T7128] RSP: 0018:ffffc900042efa88 EFLAGS: 00010093
[ 107.283659][ T7128] RAX: 0000000000000000 RBX: ffff88824013c100 RCX:
0000000000000000
[ 107.283659][ T7128] RDX: ffff888111b15140 RSI: ffffffff8119be6a RDI:
ffffffff84c6fd9e
[ 107.283659][ T7128] RBP: ffffc900042efac8 R08: 0000000000000001 R09:
0000000000000000
[ 107.283659][ T7128] R10: 0000000000000002 R11: 000000000000f2ce R12:
0000000000000000
[ 107.283659][ T7128] R13: ffff888243f14668 R14: ffff888237c2d440 R15:
ffff888240ffc000
[ 107.283659][ T7128] FS: 00007feb9a89ac80(0000)
GS:ffff888437c80000(0000) knlGS:0000000000000000
[ 107.283659][ T7128] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 107.283659][ T7128] CR2: 00007ffc849ba084 CR3: 0000000247402000 CR4:
00000000000006e0
[ 107.283659][ T7128] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 107.283659][ T7128] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 107.283659][ T7128] Call Trace:
[ 107.283659][ T7128] <TASK>
[ 107.283659][ T7128] queue_work_on+0x88/0x90
[ 107.283659][ T7128] xprt_schedule_autoclose_locked+0x7a/0xb0
[ 107.283659][ T7128] xprt_force_disconnect+0x53/0x150
[ 107.283659][ T7128] xs_local_setup_socket+0x2b2/0x480
[ 107.283659][ T7128] xs_setup_local+0x24b/0x280
[ 107.283659][ T7128] xprt_create_transport+0xb0/0x340
[ 107.283659][ T7128] rpc_create+0x104/0x2b0
[ 107.283659][ T7128] ? __this_cpu_preempt_check+0x1c/0x20
[ 107.283659][ T7128] ? lock_is_held_type+0xde/0x130
[ 107.283659][ T7128] rpcb_create_local_unix+0xb2/0x2c0
[ 107.283659][ T7128] rpcb_create_local+0x79/0x90
[ 107.283659][ T7128] svc_bind+0x92/0xd0
[ 107.283659][ T7128] nfsd_create_serv+0x131/0x3a0
[ 107.283659][ T7128] write_ports+0x2d4/0x8d0
[ 107.283659][ T7128] ? _copy_from_user+0x8b/0xe0
[ 107.283659][ T7128] ? nfsd_init_net+0x2d0/0x2d0
[ 107.283659][ T7128] nfsctl_transaction_write+0x70/0xb0
[ 107.283659][ T7128] ? export_features_show+0x30/0x30
[ 107.283659][ T7128] vfs_write+0x11d/0x4b0
[ 107.283659][ T7128] ksys_write+0xe0/0x130
[ 107.283659][ T7128] __x64_sys_write+0x23/0x30
[ 107.283659][ T7128] do_syscall_64+0x34/0xb0
[ 107.283659][ T7128] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 107.283659][ T7128] RIP: 0033:0x7feb99b00130
[ 107.283659][ T7128] Code: 73 01 c3 48 8b 0d 58 ed 2c 00 f7 d8 64 89
01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 45 2d 00 00 75 10 b8 01 00
00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 3e f3 01 00 48
89 04 24
[ 107.283659][ T7128] RSP: 002b:00007ffc849b68e8 EFLAGS: 00000246
ORIG_RAX: 0000000000000001
[ 107.283659][ T7128] RAX: ffffffffffffffda RBX: 0000000000000000 RCX:
00007feb99b00130
[ 107.283659][ T7128] RDX: 0000000000000002 RSI: 000055d532e09620 RDI:
0000000000000003
[ 107.283659][ T7128] RBP: 0000000000000003 R08: 000055d532c06704 R09:
0000000000000000
[ 107.283659][ T7128] R10: 0000000000000000 R11: 0000000000000246 R12:
0000000000000004
[ 107.283659][ T7128] R13: 000055d532e09620 R14: 000055d532c066bf R15:
000055d533474730
[ 107.283659][ T7128] </TASK>
[ 107.283659][ T7128] irq event stamp: 33702
[ 107.283659][ T7128] hardirqs last enabled at (33701):
[<ffffffff814c2288>] cmpxchg_double_slab.isra.52+0xe8/0x220
[ 107.283659][ T7128] hardirqs last disabled at (33702):
[<ffffffff8119bfc3>] queue_work_on+0x73/0x90
[ 107.283659][ T7128] softirqs last enabled at (33670):
[<ffffffff8367b7cc>] unix_release_sock+0xfc/0x540
[ 107.283659][ T7128] softirqs last disabled at (33668):
[<ffffffff8367b7a8>] unix_release_sock+0xd8/0x540
[ 107.283659][ T7128] ---[ end trace 0000000000000000 ]---
[ 107.622086][ T7128] svc: failed to register nfsdv2 RPC service (errno
111).
[ 107.627373][ T7128] svc: failed to register nfsaclv2 RPC service
(errno 111).
Job for nfs-server.service canceled.
[ 109.560632][ T7174] NFSD: Using UMH upcall client tracking operations.
[ 109.564229][ T7174] NFSD: starting 90-second grace period (net f0000000)
+
out:
xprt_clear_connecting(xprt);
xprt_wake_pending_tasks(xprt, status);
--
Wang Hai