From ec4318bcb4c59d8b8bf7037c9f444a9887ccb265 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Fri, 19 Mar 2010 13:24:39 -0700 Subject: [PATCH] ceph: fix snap rebuild condition We were rebuilding the snap context when it was not necessary (i.e. when the realm seq hadn't changed _and_ the parent seq was still older), which caused page snapc pointers to not match the realm's snapc pointer (even though the snap context itself was identical). This confused begin_write and put it into an endless loop. The correct logic is: rebuild snapc if _my_ realm seq changed, or if my parent realm's seq is newer than mine (and thus mine needs to be rebuilt too). Signed-off-by: Sage Weil --- fs/ceph/snap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 8a43bc8675eb..df04e210a055 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -314,9 +314,9 @@ static int build_snap_context(struct ceph_snap_realm *realm) because we rebuild_snap_realms() works _downward_ in hierarchy after each update.) */ if (realm->cached_context && - realm->cached_context->seq <= realm->seq && + realm->cached_context->seq == realm->seq && (!parent || - realm->cached_context->seq <= parent->cached_context->seq)) { + realm->cached_context->seq >= parent->cached_context->seq)) { dout("build_snap_context %llx %p: %p seq %lld (%d snaps)" " (unchanged)\n", realm->ino, realm, realm->cached_context, -- 2.20.1