From b9aaac5a6b7d228435fcb80963d41c274406011b Mon Sep 17 00:00:00 2001 From: jiangyiwen Date: Mon, 23 Jun 2014 13:22:09 -0700 Subject: [PATCH] ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during umount The following case may lead to endless loop during umount. node A node B node C node D umount volume, migrate lockres1 to B want to lock lockres1, send MASTER_REQUEST_MSG to C init block mle send MIGRATE_REQUEST_MSG to C find a block mle, and then return DLM_MIGRATE_RESPONSE_MASTERY_REF to B set C in refmap umount successfully try to umount, endless loop occurs when migrate lockres1 since C is in refmap So we can fix this endless loop case by only returning DLM_MIGRATE_RESPONSE_MASTERY_REF if it has a mastery mle when receiving MIGRATE_REQUEST_MSG. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: jiangyiwen Reviewed-by: Mark Fasheh Cc: Joel Becker Cc: Xue jiufei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/dlm/dlmmaster.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index 3087a21d32f9..4f4b00e173f2 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -3088,11 +3088,15 @@ static int dlm_add_migration_mle(struct dlm_ctxt *dlm, /* remove it so that only one mle will be found */ __dlm_unlink_mle(dlm, tmp); __dlm_mle_detach_hb_events(dlm, tmp); - ret = DLM_MIGRATE_RESPONSE_MASTERY_REF; - mlog(0, "%s:%.*s: master=%u, newmaster=%u, " - "telling master to get ref for cleared out mle " - "during migration\n", dlm->name, namelen, name, - master, new_master); + if (tmp->type == DLM_MLE_MASTER) { + ret = DLM_MIGRATE_RESPONSE_MASTERY_REF; + mlog(0, "%s:%.*s: master=%u, newmaster=%u, " + "telling master to get ref " + "for cleared out mle during " + "migration\n", dlm->name, + namelen, name, master, + new_master); + } } spin_unlock(&tmp->spinlock); }