From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965629AbcKJRpf (ORCPT ); Thu, 10 Nov 2016 12:45:35 -0500 Received: from smtp2.ccs.ornl.gov ([160.91.203.11]:48746 "EHLO smtp2.ccs.ornl.gov" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965102AbcKJRbn (ORCPT ); Thu, 10 Nov 2016 12:31:43 -0500 From: James Simmons To: Greg Kroah-Hartman , devel@driverdev.osuosl.org, Andreas Dilger , Oleg Drokin Cc: Linux Kernel Mailing List , Lustre Development List , wang di , James Simmons Subject: [PATCH 13/35] staging: lustre: llite: lookup master inode by ilookup5_nowait Date: Thu, 10 Nov 2016 12:30:43 -0500 Message-Id: <1478799065-24841-14-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1478799065-24841-1-git-send-email-jsimmons@infradead.org> References: <1478799065-24841-1-git-send-email-jsimmons@infradead.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: wang di Do not lookup master inode by ilookup5, instead it should use ilookup5_nowait, otherwise it will cause dead lock, 1. Client1 send chmod req to the MDT0, then on MDT0, it enqueues master and all of its slaves lock, (mdt_attr_set() ->mdt_lock_slaves()), after gets master and stripe0 lock, it will send the enqueue request(for stripe1) to MDT1, then MDT1 finds the lock has been granted to client2. Then MDT1 sends blocking ast to client2. 2. At the same time, client2 tries to unlink the striped dir (rm -rf striped_dir), and during lookup, it will hold the master inode of the striped directory, whose inode state is NEW, then tries to revalidate all of its slaves, (ll_prep_inode()->ll_iget()->ll_read_inode2()-> ll_update_inode().). And it will be blocked on the server side because of 1. 3. Then the client get the blocking_ast request, cancel the lock, but being blocked by ilookup5 in ll_md_blocking_ast(), because the inode state is still NEW. Signed-off-by: wang di Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5344 Reviewed-on: http://review.whamcloud.com/16066 Reviewed-by: John L. Hammond Reviewed-by: Lai Siyao Reviewed-by: James Simmons Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- drivers/staging/lustre/lustre/llite/namei.c | 36 ++++++++++++++++++++++++--- 1 files changed, 32 insertions(+), 4 deletions(-) diff --git a/drivers/staging/lustre/lustre/llite/namei.c b/drivers/staging/lustre/lustre/llite/namei.c index c268f32..9ea43e1 100644 --- a/drivers/staging/lustre/lustre/llite/namei.c +++ b/drivers/staging/lustre/lustre/llite/namei.c @@ -286,10 +286,38 @@ int ll_md_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc, hash = cl_fid_build_ino(&lli->lli_pfid, ll_need_32bit_api(ll_i2sbi(inode))); - - master_inode = ilookup5(inode->i_sb, hash, - ll_test_inode_by_fid, - (void *)&lli->lli_pfid); + /* + * Do not lookup the inode with ilookup5, + * otherwise it will cause dead lock, + * + * 1. Client1 send chmod req to the MDT0, then + * on MDT0, it enqueues master and all of its + * slaves lock, (mdt_attr_set() -> + * mdt_lock_slaves()), after gets master and + * stripe0 lock, it will send the enqueue req + * (for stripe1) to MDT1, then MDT1 finds the + * lock has been granted to client2. Then MDT1 + * sends blocking ast to client2. + * + * 2. At the same time, client2 tries to unlink + * the striped dir (rm -rf striped_dir), and + * during lookup, it will hold the master inode + * of the striped directory, whose inode state + * is NEW, then tries to revalidate all of its + * slaves, (ll_prep_inode()->ll_iget()-> + * ll_read_inode2()-> ll_update_inode().). And + * it will be blocked on the server side because + * of 1. + * + * 3. Then the client get the blocking_ast req, + * cancel the lock, but being blocked if using + * ->ilookup5()), because master inode state is + * NEW. + */ + master_inode = ilookup5_nowait(inode->i_sb, + hash, + ll_test_inode_by_fid, + (void *)&lli->lli_pfid); if (master_inode) { ll_invalidate_negative_children(master_inode); iput(master_inode); -- 1.7.1