From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752494AbcFTCKs (ORCPT ); Sun, 19 Jun 2016 22:10:48 -0400 Received: from linuxhacker.ru ([217.76.32.60]:56010 "EHLO fiona.linuxhacker.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752046AbcFTCJa (ORCPT ); Sun, 19 Jun 2016 22:09:30 -0400 From: Oleg Drokin To: Greg Kroah-Hartman , devel@driverdev.osuosl.org, Andreas Dilger Cc: Linux Kernel Mailing List , Lustre Development List , Patrick Farrell , Oleg Drokin Subject: [PATCH 12/28] staging/lustre/llite: take trunc_sem only at vvp layer Date: Sun, 19 Jun 2016 22:07:27 -0400 Message-Id: <1466388463-1817551-13-git-send-email-green@linuxhacker.ru> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1466388463-1817551-1-git-send-email-green@linuxhacker.ru> References: <1466388463-1817551-1-git-send-email-green@linuxhacker.ru> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Patrick Farrell The lli_trunc_sem is taken in 'read' mode in both ll_page_mkwrite and vvp_io_fault_start. This can lead to a deadlock with another thread which asks for the semaphore in write mode between thse two read calls. Since all users of lli_trunc_sem are in the vvp layer, we can satisfy the requirement to exclude truncate by taking the semaphore only in vvp_io_fault_start. Signed-off-by: Patrick Farrell Reviewed-on: http://review.whamcloud.com/19315 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7981 Reviewed-by: Jinshan Xiong Reviewed-by: Andriy Skulysh Signed-off-by: Oleg Drokin --- drivers/staging/lustre/lustre/llite/llite_mmap.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/staging/lustre/lustre/llite/llite_mmap.c b/drivers/staging/lustre/lustre/llite/llite_mmap.c index fb1c3b6..66ee5db 100644 --- a/drivers/staging/lustre/lustre/llite/llite_mmap.c +++ b/drivers/staging/lustre/lustre/llite/llite_mmap.c @@ -196,18 +196,11 @@ static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage, set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM)); - /* we grab lli_trunc_sem to exclude truncate case. - * Otherwise, we could add dirty pages into osc cache - * while truncate is on-going. - */ inode = vvp_object_inode(io->ci_obj); lli = ll_i2info(inode); - down_read(&lli->lli_trunc_sem); result = cl_io_loop(env, io); - up_read(&lli->lli_trunc_sem); - cfs_restore_sigs(set); if (result == 0) { -- 2.7.4