net/smc: longer delay for client link group removal

Client link group creation always follows the server linkgroup creation.
If peer creates a new server link group, client has to create a new
client link group. If peer reuses a server link group for a new
connection, client has to reuse its client link group as well. This
patch introduces a longer delay for client link group removal to make
sure this link group still exists, once the peer decides to reuse a
server link group. This avoids out-of-sync conditions for link groups.
If already scheduled, modify the delay.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ursula Braun 2017-09-21 09:16:31 +02:00 committed by David S. Miller
parent 8301fa44b4
commit 5bc11ddbdf
1 changed files with 12 additions and 4 deletions

View File

@ -25,8 +25,9 @@
#include "smc_cdc.h"
#include "smc_close.h"
#define SMC_LGR_NUM_INCR 256
#define SMC_LGR_FREE_DELAY (600 * HZ)
#define SMC_LGR_NUM_INCR 256
#define SMC_LGR_FREE_DELAY_SERV (600 * HZ)
#define SMC_LGR_FREE_DELAY_CLNT (SMC_LGR_FREE_DELAY_SERV + 10)
static u32 smc_lgr_num; /* unique link group number */
@ -107,8 +108,15 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn)
__smc_lgr_unregister_conn(conn);
}
write_unlock_bh(&lgr->conns_lock);
if (reduced && !lgr->conns_num)
schedule_delayed_work(&lgr->free_work, SMC_LGR_FREE_DELAY);
if (!reduced || lgr->conns_num)
return;
/* client link group creation always follows the server link group
* creation. For client use a somewhat higher removal delay time,
* otherwise there is a risk of out-of-sync link groups.
*/
mod_delayed_work(system_wq, &lgr->free_work,
lgr->role == SMC_CLNT ? SMC_LGR_FREE_DELAY_CLNT :
SMC_LGR_FREE_DELAY_SERV);
}
static void smc_lgr_free_work(struct work_struct *work)