From cbd1998377504df005302ac90d49db72a48552a6 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 30 Dec 2009 12:08:49 +1100 Subject: [PATCH] md: Fix unfortunate interaction with evms evms configures md arrays by: open device send ioctl close device for each different ioctl needed. Since 2.6.29, the device can disappear after the 'close' unless a significant configuration has happened to the device. The change made by "SET_ARRAY_INFO" can too minor to stop the device from disappearing, but important enough that losing the change is bad. So: make sure SET_ARRAY_INFO sets mddev->ctime, and keep the device active as long as ctime is non-zero (it gets zeroed with lots of other things when the array is stopped). This is suitable for -stable kernels since 2.6.29. Signed-off-by: NeilBrown Cc: stable@kernel.org --- drivers/md/md.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index f4f5f82..7862231 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -386,7 +386,9 @@ static void mddev_put(mddev_t *mddev) if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock)) return; if (!mddev->raid_disks && list_empty(&mddev->disks) && - !mddev->hold_active) { + mddev->ctime == 0 && !mddev->hold_active) { + /* Array is not configured at all, and not held active, + * so destroy it */ list_del(&mddev->all_mddevs); if (mddev->gendisk) { /* we did a probe so need to clean up. @@ -5262,6 +5264,10 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info) mddev->minor_version = info->minor_version; mddev->patch_version = info->patch_version; mddev->persistent = !info->not_persistent; + /* ensure mddev_put doesn't delete this now that there + * is some minimal configuration. + */ + mddev->ctime = get_seconds(); return 0; } mddev->major_version = MD_MAJOR_VERSION; -- 2.7.4