From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 60B81339714 for ; Mon, 22 Jun 2026 03:14:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782098052; cv=none; b=elAAjl3ZOyn1ol6Hir6ZEKt5as6thu9ws+6WLfajIX2PFmykdo4ZQKoDqfyc4kDCpFkZAQhzfItSWV9RFrruaK0UvfvOvFjsdtZRH4my9uT82eijHKq5PFV75xrXLBQFj6S4T9/rz/IQmaBDgK62IwwAlqWaqhnPsso46AswpB8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782098052; c=relaxed/simple; bh=AlEUtIsIkfR3fWyayDWBbv8ch2c7rw64P9B9Ux17tQE=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=jxIipKUyiIbTQWqshvTr2ifjK6KAr8SG+bww3WrHS5QZlZZoZqoQ9lTCC8rEztI5XAcb9KDbgbn4AOdKHEKPzbFTzjlUEjiukYvwHeLRLED6idWdJ13uzgGk0HQo+8jKSSytHRi6vm9DgQk+dQvEok86vgtiFnqDb33X/by1M/k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UYAHOgu/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UYAHOgu/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 478581F00A3A; Mon, 22 Jun 2026 03:14:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782098050; bh=Wg9sImtwFIHijEetl/E4uet0/5PPMDVY/e84ZQ61JV4=; h=Date:Cc:Subject:To:References:From:In-Reply-To; b=UYAHOgu/jbTy3e+/HECL1aZ2xrqshpRiAxeHcyNjDaYfQLEfssPi3D3rbmwFRZZrJ qaSYvlUDFWKlddR9AvKMGi/9msFh59TlR57IK4u42COif3rCL4XeprCDfCOzA7r6qC bbJIXRhMd51Y+0QuCuDoKS/RMI6tpFR/VMVA7PmLhQLJpD4pcDqTtvnLf9Nt6mvZvm RAg7wSbpdWIEivxbhFReX17I7j2PO/JqduGcbflry16EUCYxSOdIAXE+qkOekIyMCe ymAFbVsAHjoqszhn5V0dcROXEKYLMCkgPtmPYOP/7SGOoBjNNmtQmeqMMOrO9AeWln A8DtrVJhdYm+g== Message-ID: Date: Mon, 22 Jun 2026 11:14:06 +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 Cc: chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Yunji Kang , Yeongjin Gil , Sungjong Seo Subject: Re: [PATCH] f2fs: fix to round down start offset of fallocate for pin file To: Sunmin Jeong , jaegeuk@kernel.org References: <20260622023805.3620189-1-s_min.jeong@samsung.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20260622023805.3620189-1-s_min.jeong@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/22/26 10:38, Sunmin Jeong wrote: > Currently, the length of fallocate for pin file is section-aligned to > keep allocated sections from being selected as victims of GC. However, > for the case that the start offset of fallocate is not aligned in > section, the allocated sections can't be fully utilized. It's because a > new section is allocated by f2fs_allocate_pinning_section() after using > blks_per_sec blocks regardless of the start offset. As a result, several > unexpected dirty segments may be created, including blocks assigned to > the pinned file. > > To address this issue, let's round down the start offset of fallocate > to the length of section. It's good catch! > > The reproducing scenario is as below > > chunk=$(((2<<20)+4096)) # 2MB + 4KB > touch test > f2fs_io pinfile set test > f2fs_io fallocate 0 0 $chunk test > f2fs_io fallocate 0 $chunk $chunk test > f2fs_io fallocate 0 $((chunk*2)) $chunk test > f2fs_io fiemap 0 $((chunk*3)) test > > Fiemap: offset = 0 len = 12288 > logical addr. physical addr. length flags > 0 0000000000000000 000000068c600000 0000000000400000 00001088 > 1 0000000000400000 000000003d400000 0000000000001000 00001088 > 2 0000000000401000 00000003eb200000 0000000000200000 00001088 > 3 0000000000601000 00000005e4200000 0000000000001000 00001088 > 4 0000000000602000 0000000605400000 0000000000200000 00001089 > Fixes and Cc stable line. > Reviewed-by: Yunji Kang > Reviewed-by: Yeongjin Gil > Reviewed-by: Sungjong Seo > Signed-off-by: Sunmin Jeong > --- > fs/f2fs/file.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index 2c4880f24b54..3954aea43bd9 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -1906,8 +1906,13 @@ static int f2fs_expand_inode_data(struct inode *inode, loff_t offset, > > if (f2fs_is_pinned_file(inode)) { > block_t sec_blks = CAP_BLKS_PER_SEC(sbi); > - block_t sec_len = roundup(map.m_len, sec_blks); > + block_t sec_len; > > + if (map.m_lblk % sec_blks) { > + map.m_lblk = rounddown(map.m_lblk, sec_blks); > + map.m_len = pg_end - map.m_lblk; If pg_end is aligned to sec_blks, but off_end is non-zero, is there off-by-one issue? Thanks, > + } > + sec_len = roundup(map.m_len, sec_blks); > map.m_len = sec_blks; > next_alloc: > f2fs_down_write(&sbi->pin_sem);