Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753247AbdHRNiq (ORCPT ); Fri, 18 Aug 2017 09:38:46 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55470 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752772AbdHRNPr (ORCPT ); Fri, 18 Aug 2017 09:15:47 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Trond Myklebust" , "Benjamin Coddington" Date: Fri, 18 Aug 2017 14:13:20 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 070/134] NFS: Use GFP_NOIO for two allocations in writeback In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1933 Lines: 55 3.16.47-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Coddington commit ae97aa524ef495b6276fd26f5d5449fb22975d7c upstream. Prevent a deadlock that can occur if we wait on allocations that try to write back our pages. Signed-off-by: Benjamin Coddington Fixes: 00bfa30abe869 ("NFS: Create a common pgio_alloc and pgio_release...") Signed-off-by: Trond Myklebust [bwh: Backported to 3.16: - Drop changes in nfs_pageio_init() - Adjust context] Signed-off-by: Ben Hutchings --- fs/nfs/pagelist.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -29,13 +29,14 @@ static struct kmem_cache *nfs_page_cachep; static const struct rpc_call_ops nfs_pgio_common_ops; -static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount) +static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount, + gfp_t gfp_flags) { p->npages = pagecount; if (pagecount <= ARRAY_SIZE(p->page_array)) p->pagevec = p->page_array; else { - p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL); + p->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags); if (!p->pagevec) p->npages = 0; } @@ -739,9 +740,12 @@ int nfs_generic_pgio(struct nfs_pageio_d struct list_head *head = &desc->pg_list; struct nfs_commit_info cinfo; unsigned int pagecount, pageused; + gfp_t gfp_flags = GFP_KERNEL; pagecount = nfs_page_array_len(desc->pg_base, desc->pg_count); - if (!nfs_pgarray_set(&hdr->page_array, pagecount)) + if (desc->pg_rw_ops->rw_mode == FMODE_WRITE) + gfp_flags = GFP_NOIO; + if (!nfs_pgarray_set(&hdr->page_array, pagecount, gfp_flags)) return nfs_pgio_error(desc, hdr); nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);