From: Yan, Zheng Date: Mon, 20 Jul 2015 02:14:06 +0000 (+0800) Subject: ceph: fix queuing inode to mdsdir's snaprealm X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=23078637e054;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git ceph: fix queuing inode to mdsdir's snaprealm During MDS failovers, MClientSnap message may cause kclient to move some inodes from root directory's snaprealm to mdsdir's snaprealm and queue snapshots for these inodes. For a FS has never created any snapshot, both root directory's snaprealm and mdsdir's snaprealm share the same snapshot contexts (both are ceph_empty_snapc). This confuses ceph_put_wrbuffer_cap_refs(), make it unable to distinguish snapshot buffers from head buffers. The fix is do not use ceph_empty_snapc as snaprealm's cached context. Signed-off-by: Yan, Zheng --- diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 233d906aec02..4aa7122a8d38 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -338,12 +338,6 @@ static int build_snap_context(struct ceph_snap_realm *realm) return 0; } - if (num == 0 && realm->seq == ceph_empty_snapc->seq) { - ceph_get_snap_context(ceph_empty_snapc); - snapc = ceph_empty_snapc; - goto done; - } - /* alloc new snap context */ err = -ENOMEM; if (num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64)) @@ -381,7 +375,6 @@ static int build_snap_context(struct ceph_snap_realm *realm) realm->ino, realm, snapc, snapc->seq, (unsigned int) snapc->num_snaps); -done: ceph_put_snap_context(realm->cached_context); realm->cached_context = snapc; return 0;