From a39953dd95ff10e311083d94f4f95c348cb22464 Mon Sep 17 00:00:00 2001 From: Wengang Wang Date: Wed, 14 Jul 2010 22:38:21 +0800 Subject: [PATCH] ocfs2/dlm: Remove BUG_ON from migration in the rare case of a down node For migration, we are waiting for DLM_LOCK_RES_MIGRATING flag to be set before sending DLM_MIG_LOCKRES_MSG message to the target. We are using dlm_migration_can_proceed() for that purpose. However, if the node is down, dlm_migration_can_proceed() will also return "go ahead". In this rare case, the DLM_LOCK_RES_MIGRATING flag might not be set yet. Remove the BUG_ON() that trips over this condition. Signed-off-by: Wengang Wang Signed-off-by: Joel Becker --- fs/ocfs2/dlm/dlmmaster.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index 4a7506a4e314..94b97fc6a88e 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -2808,14 +2808,8 @@ static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm, mlog(0, "trying again...\n"); goto again; } - /* now that we are sure the MIGRATING state is there, drop - * the unneded state which blocked threads trying to DIRTY */ - spin_lock(&res->spinlock); - BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY)); - BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING)); - res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY; - spin_unlock(&res->spinlock); + ret = 0; /* did the target go down or die? */ spin_lock(&dlm->spinlock); if (!test_bit(target, dlm->domain_map)) { @@ -2825,10 +2819,22 @@ static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm, } spin_unlock(&dlm->spinlock); + /* + * if target is down, we need to clear DLM_LOCK_RES_BLOCK_DIRTY for + * another try; otherwise, we are sure the MIGRATING state is there, + * drop the unneded state which blocked threads trying to DIRTY + */ + spin_lock(&res->spinlock); + BUG_ON(!(res->state & DLM_LOCK_RES_BLOCK_DIRTY)); + res->state &= ~DLM_LOCK_RES_BLOCK_DIRTY; + if (!ret) + BUG_ON(!(res->state & DLM_LOCK_RES_MIGRATING)); + spin_unlock(&res->spinlock); + /* * at this point: * - * o the DLM_LOCK_RES_MIGRATING flag is set + * o the DLM_LOCK_RES_MIGRATING flag is set if target not down * o there are no pending asts on this lockres * o all processes trying to reserve an ast on this * lockres must wait for the MIGRATING flag to clear -- GitLab