When a parameter is permanently changed on the MGS the MGS send a changelog packet to the proper nodes that are affected by the change. Once the nodes receive the change they then call the userland utility lctl to change its local value. When calling a userland application from the kernel you specify a flag to control the interaction with the application. Originally by default the flag was set to 0 which is UMH_NO_WAIT which meant lctl was being called asynchronously. In older kernels this was fine since UHM_NO_WAIT and UHM_WAIT_PROC had nearly the same logic. This changed with newer kernels which broke updating our parameters. Plus doing a UHM_NO_WAIT doesn't report back a error if something goes wrong with lctl. The fix is to set the flag to UHM_WAIT_PROC so kernel space waits until lctl has finished and we get a proper error code if something does go wrong with lctl. Signed-off-by: James Simmons <uja.ornl@xxxxxxxxx> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6063 Reviewed-on: http://review.whamcloud.com/13677 Reviewed-by: Bob Glossman <bob.glossman@xxxxxxxxx> Reviewed-by: Andreas Dilger <andreas.dilger@xxxxxxxxx> Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx> --- .../staging/lustre/lustre/obdclass/obd_config.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/staging/lustre/lustre/obdclass/obd_config.c b/drivers/staging/lustre/lustre/obdclass/obd_config.c index fddfc9c..bbed1b7 100644 --- a/drivers/staging/lustre/lustre/obdclass/obd_config.c +++ b/drivers/staging/lustre/lustre/obdclass/obd_config.c @@ -738,7 +738,7 @@ static int process_param2_config(struct lustre_cfg *lcfg) } start = ktime_get(); - rc = call_usermodehelper(argv[0], argv, NULL, 1); + rc = call_usermodehelper(argv[0], argv, NULL, UMH_WAIT_PROC); end = ktime_get(); if (rc < 0) { -- 1.7.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
