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 Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A649AC7EE25 for ; Wed, 17 May 2023 03:04:34 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-4.v29.lw.sourceforge.com) by sfs-ml-4.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1pz7Sq-0000KT-1h; Wed, 17 May 2023 03:04:32 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-4.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pz7So-0000KM-Eb for linux-f2fs-devel@lists.sourceforge.net; Wed, 17 May 2023 03:04:30 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: Subject:From:References:Cc:To:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=itKI0JwrlwGqcjREtPN6fobhOH38lsiC83/nmZzWry0=; b=YGqgwnTDkrZB90U/iw96AY4yDx ee/Zr4o+ib3e/4JOAFi/3Um/k46vgCtTBY6n0wVALlu+2rSpy9oCjSGSLStlN34pVEE4q2LBlzOod 11xKHdnBWWzRgRYA9yOktzJQehjeNRaCNBwfwjZ6Mj9xC5bZv+zGIn2qhEZIzH3OTFgw=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:Subject:From: References:Cc:To:MIME-Version:Date:Message-ID:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=itKI0JwrlwGqcjREtPN6fobhOH38lsiC83/nmZzWry0=; b=MfV+pd6c4UKewMijKXjBefcYN/ +q7HXVTJTVXEAXKHoK6NsfuB9fXSKNgb9o+Eavu5sdNBX3OOB92EvUWqW69+3cJEi4/U8yUozl7+4 uIrsjTc6d9yUug5Spar4/mOT/dfjlH44Kzl/mzpWvSKksbLAMeXScw5Eev1CjzI8d4wo=; Received: from dfw.source.kernel.org ([139.178.84.217]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1pz7Sk-00ARBI-TG for linux-f2fs-devel@lists.sourceforge.net; Wed, 17 May 2023 03:04:30 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8240C64121; Wed, 17 May 2023 03:04:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25F9DC433D2; Wed, 17 May 2023 03:04:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684292660; bh=h+pkqZ0xoAQM4QKZdhh0T9UUWsrm1cPbu/G9EqMKV34=; h=Date:To:Cc:References:From:Subject:In-Reply-To:From; b=lE0wf3kbq1YPRYC8UaOKDlw2pMI0WEQKynHguioFAui4gGS2BGY3fcIJE5Nn9ARvj 8KlL21iD19CIoWluaz0FwfAK1ajKpV9FxWEDgRxltcybsUSXulIHxbbjshixg5DKj1 XB5fPX0cCIAJN2GEI/Mo5elz9a0X9Rnmr1SZ5W/JXgQdi4FvKRIO8QxkSnOcbq1Ny2 8dxdcENXfHOXHnZ8r2NLvNOBePT1tbfKIXyYLHQLtG5EPjJfkwjhfrOv6U0eT+470L 30K6wnFhYrsZ7GbU6o+c4qzbfbpmceB2UFJzhFj0X3EIHUl99G7B7krVG/473gH+LR mT+gIvSGvMxRA== Message-ID: Date: Wed, 17 May 2023 11:04:17 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Content-Language: en-US To: Chunhai Guo References: <20230516142722.18931-1-guochunhai@vivo.com> From: Chao Yu In-Reply-To: <20230516142722.18931-1-guochunhai@vivo.com> X-Headers-End: 1pz7Sk-00ARBI-TG Subject: Re: [f2fs-dev] [PATCH v2] fsck.f2fs: Detect and fix looped node chain efficiently X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net, frank.li@vivo.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On 2023/5/16 22:27, Chunhai Guo wrote: > find_fsync_inode() detect the looped node chain by comparing the loop > counter with free blocks. While it may take tens of seconds to quit when > the free blocks are large enough. We can use Floyd's cycle detection > algorithm to make the detection more efficient, and fix the issue by > filling a NULL address in the last node of the chain. > > Below is the log we encounter on a 256GB UFS storage and it takes about > 25 seconds to detect looped node chain. After changing the algorithm, it > takes about 20ms to finish the same job. > > [ 10.822904] fsck.f2fs: Info: version timestamp cur: 17, prev: 430 > [ 10.822949] fsck.f2fs: [update_superblock: 762] Info: Done to > update superblock > [ 10.822953] fsck.f2fs: Info: superblock features = 1499 : > encrypt verity extra_attr project_quota quota_ino casefold > [ 10.822956] fsck.f2fs: Info: superblock encrypt level = 0, salt = > 00000000000000000000000000000000 > [ 10.822960] fsck.f2fs: Info: total FS sectors = 59249811 (231444 > MB) > [ 35.852827] fsck.f2fs: detect looped node chain, > blkaddr:1114802, next:1114803 > [ 35.852842] fsck.f2fs: [f2fs_do_mount:3846] record_fsync_data > failed > [ 35.856106] fsck.f2fs: fsck.f2fs terminated by exit(255) > > Signed-off-by: Chunhai Guo > --- > fsck/mount.c | 122 +++++++++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 104 insertions(+), 18 deletions(-) > > diff --git a/fsck/mount.c b/fsck/mount.c > index df0314d57caf..478043035c95 100644 > --- a/fsck/mount.c > +++ b/fsck/mount.c > @@ -3394,22 +3394,89 @@ static void destroy_fsync_dnodes(struct list_head *head) > del_fsync_inode(entry); > } > > +static int find_node_blk_fast(struct f2fs_sb_info *sbi, block_t *blkaddr_fast, > + struct f2fs_node *node_blk_fast, bool *is_detecting) > +{ > + int i, err; > + > + for (i = 0; i < 2; i++) { > + if (!f2fs_is_valid_blkaddr(sbi, *blkaddr_fast, META_POR)) { > + *is_detecting = false; > + return 0; > + } > + > + err = dev_read_block(node_blk_fast, *blkaddr_fast); > + if (err) > + return err; > + > + if (!is_recoverable_dnode(sbi, node_blk_fast)) { > + *is_detecting = false; > + return 0; > + } > + > + *blkaddr_fast = next_blkaddr_of_node(node_blk_fast); > + } > + > + return 0; > +} > + > +static int loop_node_chain_fix(struct f2fs_sb_info *sbi, > + block_t blkaddr_fast, struct f2fs_node *node_blk_fast, > + block_t blkaddr, struct f2fs_node *node_blk) > +{ > + block_t blkaddr_entry, blkaddr_tmp; > + int err; > + > + /* find the entry point of the looped node chain */ > + while (blkaddr_fast != blkaddr) { > + err = dev_read_block(node_blk_fast, blkaddr_fast); > + if (err) > + return err; > + blkaddr_fast = next_blkaddr_of_node(node_blk_fast); > + > + err = dev_read_block(node_blk, blkaddr); > + if (err) > + return err; > + blkaddr = next_blkaddr_of_node(node_blk); > + } > + blkaddr_entry = blkaddr; > + > + /* find the last node of the chain */ > + do { > + blkaddr_tmp = blkaddr; > + err = dev_read_block(node_blk, blkaddr); > + if (err) > + return err; > + blkaddr = next_blkaddr_of_node(node_blk); > + } while (blkaddr != blkaddr_entry); > + > + /* fix the blkaddr of last node with NULL_ADDR. */ > + node_blk->footer.next_blkaddr = NULL_ADDR; If node_blk is inode block, the change will break its chksum. Or we can record blkaddr_tmp into f2fs_configuration? And break the loop once we traverse to the blkaddr during find_fsync_inode() and traverse_dnodes()? > + err = dev_write_block(node_blk, blkaddr_tmp); > + if (!err) > + FIX_MSG("Fix looped node chain on blkaddr %u\n", > + blkaddr_tmp); > + > + return err; > +} > + > static int find_fsync_inode(struct f2fs_sb_info *sbi, struct list_head *head) > { > struct curseg_info *curseg; > - struct f2fs_node *node_blk; > - block_t blkaddr; > - unsigned int loop_cnt = 0; > - unsigned int free_blocks = MAIN_SEGS(sbi) * sbi->blocks_per_seg - > - sbi->total_valid_block_count; > + struct f2fs_node *node_blk, *node_blk_fast; > + block_t blkaddr, blkaddr_fast; > + bool is_detecting = true; > int err = 0; > > + node_blk = calloc(F2FS_BLKSIZE, 1); > + node_blk_fast = calloc(F2FS_BLKSIZE, 1); > + ASSERT(node_blk && node_blk_fast); > + > +retry: > /* get node pages in the current segment */ > curseg = CURSEG_I(sbi, CURSEG_WARM_NODE); > blkaddr = NEXT_FREE_BLKADDR(sbi, curseg); > - > - node_blk = calloc(F2FS_BLKSIZE, 1); > - ASSERT(node_blk); > + blkaddr_fast = blkaddr; > > while (1) { > struct fsync_inode_entry *entry; > @@ -3440,19 +3507,38 @@ static int find_fsync_inode(struct f2fs_sb_info *sbi, struct list_head *head) > if (IS_INODE(node_blk) && is_dent_dnode(node_blk)) > entry->last_dentry = blkaddr; > next: > - /* sanity check in order to detect looped node chain */ > - if (++loop_cnt >= free_blocks || > - blkaddr == next_blkaddr_of_node(node_blk)) { > - MSG(0, "\tdetect looped node chain, blkaddr:%u, next:%u\n", > - blkaddr, > - next_blkaddr_of_node(node_blk)); > - err = -1; > - break; > - } > - > blkaddr = next_blkaddr_of_node(node_blk); > + > + /* sanity check to detect looped node chain with Floyd's cycle > + * detection algorithm > + */ > + if (is_detecting) { > + err = find_node_blk_fast(sbi, &blkaddr_fast, node_blk_fast, > + &is_detecting); > + if (err) > + break; > + > + if (blkaddr_fast == blkaddr) { if (blkaddr_fast != blkaddr) continue; err = loop_node_chain_fix() if (err) break; To avoid too many indentions. Thanks, > + MSG(0, "\tdetect looped node chain, blkaddr:%u\n", > + blkaddr); > + > + err = loop_node_chain_fix(sbi, > + NEXT_FREE_BLKADDR(sbi, curseg), > + node_blk_fast, blkaddr, node_blk); > + if (!err) { > + /* after fixing the looped node chain, > + * retry agian. > + */ > + is_detecting = false; > + destroy_fsync_dnodes(head); > + goto retry; > + } else > + break; > + } > + } > } > > + free(node_blk_fast); > free(node_blk); > return err; > } _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel