4.9-stable review patch. If anyone has any objections, please let me know.
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From: Yan, Zheng zyan@redhat.com
commit 04242ff3ac0abbaa4362f97781dac268e6c3541a upstream.
Otherwise, mdsc->snap_flush_list may get corrupted.
Cc: stable@vger.kernel.org Signed-off-by: "Yan, Zheng" zyan@redhat.com Reviewed-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/ceph/snap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -609,7 +609,8 @@ int __ceph_finish_cap_snap(struct ceph_i capsnap->size);
spin_lock(&mdsc->snap_flush_lock); - list_add_tail(&ci->i_snap_flush_item, &mdsc->snap_flush_list); + if (list_empty(&ci->i_snap_flush_item)) + list_add_tail(&ci->i_snap_flush_item, &mdsc->snap_flush_list); spin_unlock(&mdsc->snap_flush_lock); return 1; /* caller may want to ceph_flush_snaps */ }