[ Upstream commit e6d71b437abc2f249e3b6a1ae1a7228e09c6e563 ]
We found a data corruption issue during testing of SMC-R on Redis
applications.
The benchmark has a low probability of reporting a strange error as
shown below.
"Error: Protocol error, got "\xe2" as reply type byte"
Finally, we found that the retrieved error data was as follows:
0xE2 0xD4 0xC3 0xD9 0x04 0x00 0x2C 0x20 0xA6 0x56 0x00 0x16 0x3E 0x0C
0xCB 0x04 0x02 0x01 0x00 0x00 0x20 0x00 0x00 0x00 0x00 0x00 0x00 0x00
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0xE2
It is quite obvious that this is a SMC DECLINE message, which means that
the applications received SMC protocol message.
We found that this was caused by the following situations:
client server
¦ clc proposal
------------->
¦ clc accept
<-------------
¦ clc confirm
------------->
wait llc confirm
send llc confirm
¦failed llc confirm
¦ x------
(after 2s)timeout
wait llc confirm rsp
wait decline
(after 1s) timeout
(after 2s) timeout
¦ decline
-------------->
¦ decline
<--------------
As a result, a decline message was sent in the implementation, and this
message was read from TCP by the already-fallback connection.
This patch double the client timeout as 2x of the server value,
With this simple change, the Decline messages should never cross or
collide (during Confirm link timeout).
This issue requires an immediate solution, since the protocol updates
involve a more long-term solution.
Fixes: 0fb0b02bd6fd ("net/smc: adapt SMC client code to use the LLC flow")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5211c9729484c923f8d2e06bd29f9322cc42bb8f ]
Considering scenario:
smc_cdc_rx_handler
__smc_release
sock_set_flag
smc_close_active()
sock_set_flag
__set_bit(DEAD) __set_bit(DONE)
Dues to __set_bit is not atomic, the DEAD or DONE might be lost.
if the DEAD flag lost, the state SMC_CLOSED will be never be reached
in smc_close_passive_work:
if (sock_flag(sk, SOCK_DEAD) &&
smc_close_sent_any_close(conn)) {
sk->sk_state = SMC_CLOSED;
} else {
/* just shutdown, but not yet closed locally */
sk->sk_state = SMC_APPFINCLOSEWAIT;
}
Replace sock_set_flags or __set_bit to set_bit will fix this problem.
Since set_bit is atomic.
Fixes: b38d732477e4 ("smc: socket closing and linkgroup cleanup")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
