From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3DD5F748D for ; Sun, 13 Apr 2025 01:06:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744506395; cv=none; b=TmCiy9lTqnGX5ssruoh/oVZ7Fp9+6iGwnadZnmR0195iNXFhoDkr9HueiWHuj6DPUDK+3CrlZKcuVJFQpm60KI/Ea3CR9WG4KMYHf3SUoyWaDVI0XJIHXNIMaSi3qEJUPpacyxWdzOiZcI2IeikrJNJXZIhsr9KGpvFLaLt0sbA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744506395; c=relaxed/simple; bh=d0wA6a6TtBmEed+kgWCkBfOhY66giIqSV44DkNJ4s8Q=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=a3uGbFDjoDMOb3LwSuliu258K+nUhVDEYxbFHH9UStJvh+123WgZRoh+M5YW8LE7yzNbyeO9QRbO21Proo4qAGYKFXFhZ7whZhXkBBWlqwdtFL5tYXYt5DDaNmOW3SvEfW0sf9y1Zkrr4Bf1toTxd3CTy++ONvVfMjKSZOmBKr0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=N9GDuLVQ; arc=none smtp.client-ip=115.124.30.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="N9GDuLVQ" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1744506382; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=Zym7YaQFhQbQMwDL8fOjFl5O2aHMu5cA1dfh0u/fOgM=; b=N9GDuLVQGXqM57Rx5IUV9M9d+sT7SX4McrO7cevZL0Kw0pV3Cn5zTnu7bmU5MRGezIso77urWGJ335UbfJHCUVQSb+c+gGtJBI10blw/scva3Tjz3MSm+Vty66ht8v8EolfRd23Dz2N6w8tvxeQ9yssoZM3HR1COqf4Hj9i+Dds= Received: from 30.13.190.220(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0WWZdRRE_1744506381 cluster:ay36) by smtp.aliyun-inc.com; Sun, 13 Apr 2025 09:06:22 +0800 Message-ID: Date: Sun, 13 Apr 2025 09:06:21 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/1] ocfs2: fix the issue with discontiguous allocation in the global_bitmap To: Heming Zhao , akpm Cc: ocfs2-devel@lists.linux.dev, linux-kernel@vger.kernel.org, gautham.ananthakrishna@oracle.com References: <20250408152311.16196-1-heming.zhao@suse.com> <20250408152311.16196-2-heming.zhao@suse.com> From: Joseph Qi In-Reply-To: <20250408152311.16196-2-heming.zhao@suse.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2025/4/8 23:23, Heming Zhao wrote: > The commit 4eb7b93e0310 ("ocfs2: improve write IO performance when > fragmentation is high") introduced another regression. > > The following ocfs2-test case can trigger this issue: >> ${RESV_UNWRITTEN_BIN} -f ${WORK_PLACE}/large_testfile -s 0 -l \ >> $((${FILE_MAJOR_SIZE_M}*1024*1024)) > > In my env, test disk size (by "fdisk -l "): >> 53687091200 bytes, 104857600 sectors. > > Above command is: >> /usr/local/ocfs2-test/bin/resv_unwritten -f \ >> /mnt/ocfs2/ocfs2-activate-discontig-bg-dir/large_testfile -s 0 -l \ >> 53187969024 > > Error log: >> [*] Reserve 50724M space for a LARGE file, reserve 200M space for future test. >> ioctl error 28: "No space left on device" >> resv allocation failed Unknown error -1 >> reserve unwritten region from 0 to 53187969024. > > Call flow: > __ocfs2_change_file_space //by ioctl OCFS2_IOC_RESVSP64 > ocfs2_allocate_unwritten_extents //start:0 len:53187969024 > while() > + ocfs2_get_clusters //cpos:0, alloc_size:1623168 (cluster number) > + ocfs2_extend_allocation > + ocfs2_lock_allocators > | + choose OCFS2_AC_USE_MAIN & ocfs2_cluster_group_search > | > + ocfs2_add_inode_data > ocfs2_add_clusters_in_btree > __ocfs2_claim_clusters > ocfs2_claim_suballoc_bits > + During the allocation of the final part of the large file > (around 47GB), no chain had the required contiguous > bits_wanted. Consequently, the allocation failed. > > How to fix: > When OCFS2 is encountering fragmented allocation, the file system should > stop attempting bits_wanted contiguous allocation and instead provide the > largest available contiguous free bits from the cluster groups. > > Signed-off-by: Heming Zhao > Fixes: 4eb7b93e0310 ("ocfs2: improve write IO performance when fragmentation is high") > --- > fs/ocfs2/suballoc.c | 36 +++++++++++++++++++++++++++++------- > 1 file changed, 29 insertions(+), 7 deletions(-) > > diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c > index fde75f2af37a..2e1689fc6cf7 100644 > --- a/fs/ocfs2/suballoc.c > +++ b/fs/ocfs2/suballoc.c > @@ -1796,6 +1796,7 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac, > { > int status; > u16 chain; > + u32 contig_bits; > u64 next_group; > struct inode *alloc_inode = ac->ac_inode; > struct buffer_head *group_bh = NULL; > @@ -1821,10 +1822,23 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac, > status = -ENOSPC; > /* for now, the chain search is a bit simplistic. We just use > * the 1st group with any empty bits. */ > - while ((status = ac->ac_group_search(alloc_inode, group_bh, > - bits_wanted, min_bits, > - ac->ac_max_block, > - res)) == -ENOSPC) { > + while (1) { > + if (ac->ac_which == OCFS2_AC_USE_MAIN_DISCONTIG) { > + contig_bits = le16_to_cpu(bg->bg_contig_free_bits); > + if (!contig_bits) > + contig_bits = ocfs2_find_max_contig_free_bits(bg->bg_bitmap, > + le16_to_cpu(bg->bg_bits), 0); > + if (bits_wanted > contig_bits) > + bits_wanted = contig_bits; > + if (bits_wanted < min_bits) > + bits_wanted = min_bits; This seems only valid when bits_wanted changed? BTW, the previous fix hasn't been merged yet: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/fs/ocfs2?h=next-20250411&id=767ba8b7cba3ca7a560d632f267f7aea35d54810 So should we drop that first and fold it into a whole one? Thanks, Joseph > + } > + > + status = ac->ac_group_search(alloc_inode, group_bh, > + bits_wanted, min_bits, > + ac->ac_max_block, res); > + if (status != -ENOSPC) > + break; > if (!bg->bg_next_group) > break; > > @@ -1984,6 +1998,7 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac, > victim = ocfs2_find_victim_chain(cl); > ac->ac_chain = victim; > > +search: > status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, > res, &bits_left); > if (!status) { > @@ -2024,6 +2039,16 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac, > } > } > > + /* Chains can't supply the bits_wanted contiguous space. > + * We should switch to using every single bit when allocating > + * from the global bitmap. */ > + if (i == le16_to_cpu(cl->cl_next_free_rec) && > + status == -ENOSPC && ac->ac_which == OCFS2_AC_USE_MAIN) { > + ac->ac_which = OCFS2_AC_USE_MAIN_DISCONTIG; > + ac->ac_chain = victim; > + goto search; > + } > + > set_hint: > if (status != -ENOSPC) { > /* If the next search of this group is not likely to > @@ -2432,9 +2457,6 @@ int ocfs2_claim_clusters(handle_t *handle, > { > unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given; > > - if (ac->ac_which == OCFS2_AC_USE_MAIN_DISCONTIG) > - bits_wanted = min_clusters; > - > return __ocfs2_claim_clusters(handle, ac, min_clusters, > bits_wanted, cluster_start, num_clusters); > }