From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 017BBC3276C for ; Thu, 2 Jan 2020 22:59:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6CA620866 for ; Thu, 2 Jan 2020 22:59:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578005946; bh=OKseluqIOLKPXGDIT2P+FxfP6IiKBsOcbvgBxl8Gx8c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=f6peQkJH2f+Y1Z3aRlCrziMU76vKJlGtq1NlEOchFTY3cNveHXuuBlSNyA21K6b1A 7XEIl35+fSghyG7jzCPfSqivaGqhTBkS8jTW7ltNp/+MTCqVB1ze4sbeuTLRlKLkou gdlgdGIyNnZPnk0onTMhs9mv0KIeeWf7NmEiCStk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727957AbgABWOq (ORCPT ); Thu, 2 Jan 2020 17:14:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:55022 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727146AbgABWOl (ORCPT ); Thu, 2 Jan 2020 17:14:41 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D1D6822314; Thu, 2 Jan 2020 22:14:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578003280; bh=OKseluqIOLKPXGDIT2P+FxfP6IiKBsOcbvgBxl8Gx8c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SNvFI7rf62rlz2v546VCo1u+4W2f9qGekUuBio0zkZ7WhEzmA60BLPS/lrTr4BvK5 6vpNjEsSeEo3/NyAvRb/HPOaDLNNw2PgSo3Bua8p/fAVTed88PVA8DIHyCZc4KTSBY z8+LOiOvKnGOwBB/WwjEin3Al+QRv4tnU04fDR3s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chao Yu , Sahitya Tummala , Jaegeuk Kim , Sasha Levin Subject: [PATCH 5.4 095/191] f2fs: Fix deadlock in f2fs_gc() context during atomic files handling Date: Thu, 2 Jan 2020 23:06:17 +0100 Message-Id: <20200102215840.097249623@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102215829.911231638@linuxfoundation.org> References: <20200102215829.911231638@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sahitya Tummala [ Upstream commit 677017d196ba2a4cfff13626b951cc9a206b8c7c ] The FS got stuck in the below stack when the storage is almost full/dirty condition (when FG_GC is being done). schedule_timeout io_schedule_timeout congestion_wait f2fs_drop_inmem_pages_all f2fs_gc f2fs_balance_fs __write_node_page f2fs_fsync_node_pages f2fs_do_sync_file f2fs_ioctl The root cause for this issue is there is a potential infinite loop in f2fs_drop_inmem_pages_all() for the case where gc_failure is true and when there an inode whose i_gc_failures[GC_FAILURE_ATOMIC] is not set. Fix this by keeping track of the total atomic files currently opened and using that to exit from this condition. Fix-suggested-by: Chao Yu Signed-off-by: Chao Yu Signed-off-by: Sahitya Tummala Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/f2fs.h | 1 + fs/f2fs/file.c | 1 + fs/f2fs/segment.c | 21 +++++++++++++++------ 3 files changed, 17 insertions(+), 6 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index f078cd20dab8..9046432b87c2 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1289,6 +1289,7 @@ struct f2fs_sb_info { unsigned int gc_mode; /* current GC state */ unsigned int next_victim_seg[2]; /* next segment in victim section */ /* for skip statistic */ + unsigned int atomic_files; /* # of opened atomic file */ unsigned long long skipped_atomic_files[2]; /* FG_GC and BG_GC */ unsigned long long skipped_gc_rwsem; /* FG_GC only */ diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 29bc0a542759..8ed8e4328bd1 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1890,6 +1890,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) spin_lock(&sbi->inode_lock[ATOMIC_FILE]); if (list_empty(&fi->inmem_ilist)) list_add_tail(&fi->inmem_ilist, &sbi->inode_list[ATOMIC_FILE]); + sbi->atomic_files++; spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); /* add inode in inmem_list first and set atomic_file */ diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 808709581481..7d8578401267 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -288,6 +288,8 @@ void f2fs_drop_inmem_pages_all(struct f2fs_sb_info *sbi, bool gc_failure) struct list_head *head = &sbi->inode_list[ATOMIC_FILE]; struct inode *inode; struct f2fs_inode_info *fi; + unsigned int count = sbi->atomic_files; + unsigned int looped = 0; next: spin_lock(&sbi->inode_lock[ATOMIC_FILE]); if (list_empty(head)) { @@ -296,22 +298,26 @@ next: } fi = list_first_entry(head, struct f2fs_inode_info, inmem_ilist); inode = igrab(&fi->vfs_inode); + if (inode) + list_move_tail(&fi->inmem_ilist, head); spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); if (inode) { if (gc_failure) { - if (fi->i_gc_failures[GC_FAILURE_ATOMIC]) - goto drop; - goto skip; + if (!fi->i_gc_failures[GC_FAILURE_ATOMIC]) + goto skip; } -drop: set_inode_flag(inode, FI_ATOMIC_REVOKE_REQUEST); f2fs_drop_inmem_pages(inode); +skip: iput(inode); } -skip: congestion_wait(BLK_RW_ASYNC, HZ/50); cond_resched(); + if (gc_failure) { + if (++looped >= count) + return; + } goto next; } @@ -327,13 +333,16 @@ void f2fs_drop_inmem_pages(struct inode *inode) mutex_unlock(&fi->inmem_lock); } - clear_inode_flag(inode, FI_ATOMIC_FILE); fi->i_gc_failures[GC_FAILURE_ATOMIC] = 0; stat_dec_atomic_write(inode); spin_lock(&sbi->inode_lock[ATOMIC_FILE]); if (!list_empty(&fi->inmem_ilist)) list_del_init(&fi->inmem_ilist); + if (f2fs_is_atomic_file(inode)) { + clear_inode_flag(inode, FI_ATOMIC_FILE); + sbi->atomic_files--; + } spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); } -- 2.20.1