From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: [PATCH] ceph: set up page array mempool with correct size Date: Mon, 01 Apr 2013 10:49:23 -0500 Message-ID: <5159AC83.4060007@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ia0-f171.google.com ([209.85.210.171]:47962 "EHLO mail-ia0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756728Ab3DAPt1 (ORCPT ); Mon, 1 Apr 2013 11:49:27 -0400 Received: by mail-ia0-f171.google.com with SMTP id z13so1998083iaz.2 for ; Mon, 01 Apr 2013 08:49:26 -0700 (PDT) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "ceph-devel@vger.kernel.org" In create_fs_client() a memory pool is set up be used for arrays of pages that might be needed in ceph_writepages_start() if memory is tight. There are two problems with the way it's initialized: - The size provided is the number of pages we want in the array, but it should be the number of bytes required for that many page pointers. - The number of pages computed can end up being 0, while we will always need at least one page. This patch fixes both of these problems. This resolves the two simple problems defined in: http://tracker.ceph.com/issues/4603 Signed-off-by: Alex Elder --- fs/ceph/super.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/ceph/super.c b/fs/ceph/super.c index 9fe17c6c..318bee0 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -479,6 +479,8 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt, CEPH_FEATURE_FLOCK | CEPH_FEATURE_DIRLAYOUTHASH; const unsigned required_features = 0; + int page_count; + size_t size; int err = -ENOMEM; fsc = kzalloc(sizeof(*fsc), GFP_KERNEL); @@ -522,8 +524,9 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt, /* set up mempools */ err = -ENOMEM; - fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10, - fsc->mount_options->wsize >> PAGE_CACHE_SHIFT); + page_count = fsc->mount_options->wsize >> PAGE_CACHE_SHIFT; + size = sizeof (struct page *) * (page_count ? page_count : 1); + fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10, size); if (!fsc->wb_pagevec_pool) goto fail_trunc_wq; -- 1.7.9.5