From patchwork Mon Mar 6 13:14:02 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 9606085 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 857186046A for ; Mon, 6 Mar 2017 13:45:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 73E732723E for ; Mon, 6 Mar 2017 13:45:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 689042841F; Mon, 6 Mar 2017 13:45:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.4 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6A7BD28417 for ; Mon, 6 Mar 2017 13:45:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753787AbdCFNpm (ORCPT ); Mon, 6 Mar 2017 08:45:42 -0500 Received: from mail-wr0-f194.google.com ([209.85.128.194]:35333 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752779AbdCFNpZ (ORCPT ); Mon, 6 Mar 2017 08:45:25 -0500 Received: by mail-wr0-f194.google.com with SMTP id u108so17837033wrb.2; Mon, 06 Mar 2017 05:45:23 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=GAxNg8vcX3SWk4iOTQgDWUGk5JEqCUzwa1YKAS3v/jc=; b=toiv15KJmyZ3tU2vIOVI7b9E3SSeRiJyK64dlvyzD0kBum9Y7NshgpSm+xIJRBxyqt o+Hc5Rj9dlMrS7X0b2ywdoFd9t4ioZ8ekZG9hJgUM7JSL0AeX8QxdpJ+DBcfEan0pYB9 WdhUd8W8nmwVuECTNW/9o+4Fl52HJVE1vXCM+LCTrawBUSjyrlxYfhRquWHhKMuqd/4v zFSMSrOXOIHIioF3osRmLsiE55fsifAH+JVzG4xnlTN3aP9QC2FCdSgseftfNuSM5vna oM1/OMKu+FD3AWeEqdWwrDQOrWWr2tLGIB5dSbTSd6ZfidVfWRYnFV3zjVopyA2q5fBT ehWA== X-Gm-Message-State: AMke39mLVvzhs3pNJlnTzFXWcH+yxkPZYHuYI1CefFTSY6lYyLrGfRA1tDQeQQj5uVKpoQ== X-Received: by 10.223.163.195 with SMTP id m3mr13999321wrb.83.1488806059346; Mon, 06 Mar 2017 05:14:19 -0800 (PST) Received: from tiehlicka.suse.cz (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id d6sm14829593wmd.6.2017.03.06.05.14.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Mar 2017 05:14:18 -0800 (PST) From: Michal Hocko To: Andrew Morton , Cc: , Dave Chinner , djwong@kernel.org, "Theodore Ts'o" , Chris Mason , David Sterba , Jan Kara , ceph-devel@vger.kernel.org, cluster-devel@redhat.com, linux-nfs@vger.kernel.org, logfs@logfs.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mtd@lists.infradead.org, reiserfs-devel@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, linux-f2fs-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, LKML , Nikolay Borisov , Michal Hocko , Michal Hocko , "Peter Zijlstra (Intel)" Subject: [PATCH 1/7] lockdep: teach lockdep about memalloc_noio_save Date: Mon, 6 Mar 2017 14:14:02 +0100 Message-Id: <20170306131408.9828-2-mhocko@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170306131408.9828-1-mhocko@kernel.org> References: <20170306131408.9828-1-mhocko@kernel.org> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Nikolay Borisov Commit 21caf2fc1931 ("mm: teach mm by current context info to not do I/O during memory allocation") added the memalloc_noio_(save|restore) functions to enable people to modify the MM behavior by disabling I/O during memory allocation. This was further extended in Fixes: 934f3072c17c ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set"). memalloc_noio_* functions prevent allocation paths recursing back into the filesystem without explicitly changing the flags for every allocation site. However, lockdep hasn't been keeping up with the changes and it entirely misses handling the memalloc_noio adjustments. Instead, it is left to the callers of __lockdep_trace_alloc to call the function after they have shaven the respective GFP flags which can lead to false positives: [ 644.173373] ================================= [ 644.174012] [ INFO: inconsistent lock state ] [ 644.174012] 4.10.0-nbor #134 Not tainted [ 644.174012] --------------------------------- [ 644.174012] inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage. [ 644.174012] fsstress/3365 [HC0[0]:SC0[0]:HE1:SE1] takes: [ 644.174012] (&xfs_nondir_ilock_class){++++?.}, at: [] xfs_ilock+0x141/0x230 [ 644.174012] {IN-RECLAIM_FS-W} state was registered at: [ 644.174012] __lock_acquire+0x62a/0x17c0 [ 644.174012] lock_acquire+0xc5/0x220 [ 644.174012] down_write_nested+0x4f/0x90 [ 644.174012] xfs_ilock+0x141/0x230 [ 644.174012] xfs_reclaim_inode+0x12a/0x320 [ 644.174012] xfs_reclaim_inodes_ag+0x2c8/0x4e0 [ 644.174012] xfs_reclaim_inodes_nr+0x33/0x40 [ 644.174012] xfs_fs_free_cached_objects+0x19/0x20 [ 644.174012] super_cache_scan+0x191/0x1a0 [ 644.174012] shrink_slab+0x26f/0x5f0 [ 644.174012] shrink_node+0xf9/0x2f0 [ 644.174012] kswapd+0x356/0x920 [ 644.174012] kthread+0x10c/0x140 [ 644.174012] ret_from_fork+0x31/0x40 [ 644.174012] irq event stamp: 173777 [ 644.174012] hardirqs last enabled at (173777): [] __local_bh_enable_ip+0x70/0xc0 [ 644.174012] hardirqs last disabled at (173775): [] __local_bh_enable_ip+0x37/0xc0 [ 644.174012] softirqs last enabled at (173776): [] _xfs_buf_find+0x67a/0xb70 [ 644.174012] softirqs last disabled at (173774): [] _xfs_buf_find+0x5db/0xb70 [ 644.174012] [ 644.174012] other info that might help us debug this: [ 644.174012] Possible unsafe locking scenario: [ 644.174012] [ 644.174012] CPU0 [ 644.174012] ---- [ 644.174012] lock(&xfs_nondir_ilock_class); [ 644.174012] [ 644.174012] lock(&xfs_nondir_ilock_class); [ 644.174012] [ 644.174012] *** DEADLOCK *** [ 644.174012] [ 644.174012] 4 locks held by fsstress/3365: [ 644.174012] #0: (sb_writers#10){++++++}, at: [] mnt_want_write+0x24/0x50 [ 644.174012] #1: (&sb->s_type->i_mutex_key#12){++++++}, at: [] vfs_setxattr+0x6f/0xb0 [ 644.174012] #2: (sb_internal#2){++++++}, at: [] xfs_trans_alloc+0xfc/0x140 [ 644.174012] #3: (&xfs_nondir_ilock_class){++++?.}, at: [] xfs_ilock+0x141/0x230 [ 644.174012] [ 644.174012] stack backtrace: [ 644.174012] CPU: 0 PID: 3365 Comm: fsstress Not tainted 4.10.0-nbor #134 [ 644.174012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 644.174012] Call Trace: [ 644.174012] dump_stack+0x85/0xc9 [ 644.174012] print_usage_bug.part.37+0x284/0x293 [ 644.174012] ? print_shortest_lock_dependencies+0x1b0/0x1b0 [ 644.174012] mark_lock+0x27e/0x660 [ 644.174012] mark_held_locks+0x66/0x90 [ 644.174012] lockdep_trace_alloc+0x6f/0xd0 [ 644.174012] kmem_cache_alloc_node_trace+0x3a/0x2c0 [ 644.174012] ? vm_map_ram+0x2a1/0x510 [ 644.174012] vm_map_ram+0x2a1/0x510 [ 644.174012] ? vm_map_ram+0x46/0x510 [ 644.174012] _xfs_buf_map_pages+0x77/0x140 [ 644.174012] xfs_buf_get_map+0x185/0x2a0 [ 644.174012] xfs_attr_rmtval_set+0x233/0x430 [ 644.174012] xfs_attr_leaf_addname+0x2d2/0x500 [ 644.174012] xfs_attr_set+0x214/0x420 [ 644.174012] xfs_xattr_set+0x59/0xb0 [ 644.174012] __vfs_setxattr+0x76/0xa0 [ 644.174012] __vfs_setxattr_noperm+0x5e/0xf0 [ 644.174012] vfs_setxattr+0xae/0xb0 [ 644.174012] ? __might_fault+0x43/0xa0 [ 644.174012] setxattr+0x15e/0x1a0 [ 644.174012] ? __lock_is_held+0x53/0x90 [ 644.174012] ? rcu_read_lock_sched_held+0x93/0xa0 [ 644.174012] ? rcu_sync_lockdep_assert+0x2f/0x60 [ 644.174012] ? __sb_start_write+0x130/0x1d0 [ 644.174012] ? mnt_want_write+0x24/0x50 [ 644.174012] path_setxattr+0x8f/0xc0 [ 644.174012] SyS_lsetxattr+0x11/0x20 [ 644.174012] entry_SYSCALL_64_fastpath+0x23/0xc6 Let's fix this by making lockdep explicitly do the shaving of respective GFP flags. Fixes: 934f3072c17c ("mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set") Acked-by: Michal Hocko Acked-by: Peter Zijlstra (Intel) Signed-off-by: Nikolay Borisov Signed-off-by: Michal Hocko --- kernel/locking/lockdep.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 12e38c213b70..25c33dcd86d7 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -2863,6 +2864,8 @@ static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags) if (unlikely(!debug_locks)) return; + gfp_mask = memalloc_noio_flags(gfp_mask); + /* no reclaim without waiting on it */ if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) return; @@ -3854,7 +3857,7 @@ EXPORT_SYMBOL_GPL(lock_unpin_lock); void lockdep_set_current_reclaim_state(gfp_t gfp_mask) { - current->lockdep_reclaim_gfp = gfp_mask; + current->lockdep_reclaim_gfp = memalloc_noio_flags(gfp_mask); } void lockdep_clear_current_reclaim_state(void)