From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f49.google.com (mail-wr1-f49.google.com [209.85.221.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 738762EB5CD for ; Tue, 4 Nov 2025 20:42:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762288968; cv=none; b=BHQ+X2E6rHOrOuncpKNUNc0J+U11slr2ZuBFTb3q7u54shQt5DxaQV54pLi6EQlS1AopmfGEof8Z61TkMkz4pTI1IvSZMtytJldoEGqv1gPqS+rWty2xKzX5rv7DbZ2al6FNMLeC+8RimsqVp63jfno7fO6Dt+qcsJN9X8Q7fJQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762288968; c=relaxed/simple; bh=JGsJhmJeF5q8J7Ype2nL15gIcp7qqgcNpRYXX2zKA1U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=iAkL4gS9h9KgjJAht1o71E4jQ9RZ9KI/pGo8I6FaKtaSCKWJFyEz5+KRz1iyHIrtfv6kCiPLCz6nl9iXF774Jap+cBiuSfFWNvvQAGdATGuEnV45UuDlKYp1gqokf/uj+i/tUCDoQ+vUOog+ImzGXezM7458/HZnwaqeNVLCtVM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=NF4B26cu; arc=none smtp.client-ip=209.85.221.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="NF4B26cu" Received: by mail-wr1-f49.google.com with SMTP id ffacd0b85a97d-429c7e438a8so897740f8f.2 for ; Tue, 04 Nov 2025 12:42:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1762288964; x=1762893764; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=3/I2a0uZTAnglwIVDCoK1EV+nWMPjHOXPCZYdwAgCYY=; b=NF4B26cuPHjv3gz17Rsd4oUx/nd3H2cVMGfdAtWNrXbFRIn90kvaIWFt3FX9h1quZJ kLLp5i6VaIXIirF0hn9FPubdMMfmwIMNzylZN3OiRuxw32b2UMKihBm8DYldouUrhFym 2tqjhuNCieP75phG/5Dlp3EO/UP3JX5c/ckIbEo/zfl/KaTbCzNlVwJ8zwHt+CIsG2xM BbHYPVW3s4uJC6BrZ1ZN58sX2ZOp21+aJX+ytIjJG5vkbyhnIn9xz/tD7NXW599Y3jpK v8PhPVLh8vmgGdnZqIE6CobxZEn+jhXyhzFecnCon9lim+OttiR3GX6GdmzS77ICPWGM RCNA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762288964; x=1762893764; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=3/I2a0uZTAnglwIVDCoK1EV+nWMPjHOXPCZYdwAgCYY=; b=HVIx9tBmP1c9HYpdV5SgB2Vq7UyXm7xfvxRLF7zV4cK1Jq0gbNRi5g3C3ai4TjVaXU RDtIdUdKD5sMjknLB0P8RQ+Onf/bvsUbdDogBUzFXENee5CKQth7B6bDMOaC0Zgszr+8 i7vf3TgMpV0obFzASTvf6G5dYOhbzqe/6CPKjuySqfAEQuJzuFdYwcoc5mYnCmseqo6g bWTlvNITgrSklAnbfRVNVFSoMWusga97ptchrXwQl9aySd9PgNdHSj00QJR4u8Ume6e2 7pQH1IKOjVw5fpFLtq/zrSHFdgL2oOx02DSexEmOqqBmUc4pEoCLH4vUU/fmxD9m3it/ zRqA== X-Forwarded-Encrypted: i=1; AJvYcCWW68a0fKqI+4jMGgh4/BNzqsLESQRA5uuFgc5/s4E2qB6wgsj0cAEE7QSgeLBt/MeaIgSA1HqF/GrfVDos@vger.kernel.org X-Gm-Message-State: AOJu0YzP1RT3CWMkJBGhmALRtcO2Y3cxkV5CNu3XoFANYdQEm4H/lAdy f7Jaqg6jPGi3s6JLYOKaftAy8WT9aCsVcxhazuRGpe4zrJ57T4i0C1hSOugItXwIyNI= X-Gm-Gg: ASbGncsluzXfTGDyhJOIzVCKczSwVgFNYH99+ldhyVHPfoMKIHqGBSSCA/GbJBMkGoo Z+6VYzPWiBFXFxrgGNbfXfPtUN5Q55UpbIwVDKA3dSYR9nihgI5PXt84uJnrgAg/WuT2EivfJ5G iWkURPR1hWAFfuS4iX5G3qNuvkvy3TvyAFqsMPT/wm+tCjTilDypqGI6kIZBMxO8fhBI2120xTu R7FUdn9lbAVhJuOhls/rNXr1zGQRNNg6bpds7n6dCTDpOVDcGFPbsvVKggQHvkaRbN2NaBcj8Tb vrV0tJgMsxU5G/coiarZv5JNwT8th5D38rNZdJTYumFtAJ1LfSxkDDMGAEMOiT9EyBWCkfyk6U4 IhcUerNkHPCO7bu/KssVudklLeQjYDuArG6Ayei2UQstauzcqHmadj8B5dHL3exnNir69N4DHWz sU2JQpg9h4XKhgc2ac3Gb5V/J78QzN X-Google-Smtp-Source: AGHT+IG8Z203PhFCyhJhz48A8l8UhXjLU1AaikFIf0iJkmfVY5x+Gi/GZMr6bL+04r89yb9RlNQzVA== X-Received: by 2002:a05:6000:26d3:b0:429:c851:69bc with SMTP id ffacd0b85a97d-429e32dd761mr472461f8f.8.1762288963767; Tue, 04 Nov 2025 12:42:43 -0800 (PST) Received: from ?IPV6:2403:580d:fda1::e9d? (2403-580d-fda1--e9d.ip6.aussiebb.net. [2403:580d:fda1::e9d]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7acd3246e7bsm3976191b3a.8.2025.11.04.12.42.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 04 Nov 2025 12:42:43 -0800 (PST) Message-ID: <247c8075-60d3-4090-a76d-8d59d9e859ca@suse.com> Date: Wed, 5 Nov 2025 07:12:38 +1030 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC 2/8] btrfs: use super write guard in btrfs_reclaim_bgs_work() To: Christian Brauner , linux-fsdevel@vger.kernel.org Cc: Alexander Viro , Jan Kara , linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org References: <20251104-work-guards-v1-0-5108ac78a171@kernel.org> <20251104-work-guards-v1-2-5108ac78a171@kernel.org> Content-Language: en-US From: Qu Wenruo Autocrypt: addr=wqu@suse.com; keydata= xsBNBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAHNGFF1IFdlbnJ1byA8d3F1QHN1c2UuY29tPsLAlAQTAQgAPgIbAwULCQgHAgYVCAkKCwIE FgIDAQIeAQIXgBYhBC3fcuWlpVuonapC4cI9kfOhJf6oBQJnEXVgBQkQ/lqxAAoJEMI9kfOh Jf6o+jIH/2KhFmyOw4XWAYbnnijuYqb/obGae8HhcJO2KIGcxbsinK+KQFTSZnkFxnbsQ+VY fvtWBHGt8WfHcNmfjdejmy9si2jyy8smQV2jiB60a8iqQXGmsrkuR+AM2V360oEbMF3gVvim 2VSX2IiW9KERuhifjseNV1HLk0SHw5NnXiWh1THTqtvFFY+CwnLN2GqiMaSLF6gATW05/sEd V17MdI1z4+WSk7D57FlLjp50F3ow2WJtXwG8yG8d6S40dytZpH9iFuk12Sbg7lrtQxPPOIEU rpmZLfCNJJoZj603613w/M8EiZw6MohzikTWcFc55RLYJPBWQ+9puZtx1DopW2jOwE0EWdWB rwEIAKpT62HgSzL9zwGe+WIUCMB+nOEjXAfvoUPUwk+YCEDcOdfkkM5FyBoJs8TCEuPXGXBO Cl5P5B8OYYnkHkGWutAVlUTV8KESOIm/KJIA7jJA+Ss9VhMjtePfgWexw+P8itFRSRrrwyUf E+0WcAevblUi45LjWWZgpg3A80tHP0iToOZ5MbdYk7YFBE29cDSleskfV80ZKxFv6koQocq0 vXzTfHvXNDELAuH7Ms/WJcdUzmPyBf3Oq6mKBBH8J6XZc9LjjNZwNbyvsHSrV5bgmu/THX2n g/3be+iqf6OggCiy3I1NSMJ5KtR0q2H2Nx2Vqb1fYPOID8McMV9Ll6rh8S8AEQEAAcLAfAQY AQgAJgIbDBYhBC3fcuWlpVuonapC4cI9kfOhJf6oBQJnEXWBBQkQ/lrSAAoJEMI9kfOhJf6o cakH+QHwDszsoYvmrNq36MFGgvAHRjdlrHRBa4A1V1kzd4kOUokongcrOOgHY9yfglcvZqlJ qfa4l+1oxs1BvCi29psteQTtw+memmcGruKi+YHD7793zNCMtAtYidDmQ2pWaLfqSaryjlzR /3tBWMyvIeWZKURnZbBzWRREB7iWxEbZ014B3gICqZPDRwwitHpH8Om3eZr7ygZck6bBa4MU o1XgbZcspyCGqu1xF/bMAY2iCDcq6ULKQceuKkbeQ8qxvt9hVxJC2W3lHq8dlK1pkHPDg9wO JoAXek8MF37R8gpLoGWl41FIUb3hFiu3zhDDvslYM4BmzI18QgQTQnotJH8= In-Reply-To: <20251104-work-guards-v1-2-5108ac78a171@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 在 2025/11/4 22:42, Christian Brauner 写道: > Signed-off-by: Christian Brauner > --- > fs/btrfs/block-group.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c > index 5322ef2ae015..8284b9435758 100644 > --- a/fs/btrfs/block-group.c > +++ b/fs/btrfs/block-group.c > @@ -1850,7 +1850,7 @@ void btrfs_reclaim_bgs_work(struct work_struct *work) > if (!btrfs_should_reclaim(fs_info)) > return; > > - sb_start_write(fs_info->sb); > + guard(super_write)(fs_info->sb); > > if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) { > sb_end_write(fs_info->sb); This one is still left using the old scheme, and there is another one in the mutex_trylock() branch. I'm wondering how safe is the new scope based auto freeing. Like when the freeing function is called? Will it break the existing freeing/locking sequence in other locations? For this call site, sb_end_write() is always called last so it's fine. Thanks, Qu > @@ -2030,7 +2030,6 @@ void btrfs_reclaim_bgs_work(struct work_struct *work) > list_splice_tail(&retry_list, &fs_info->reclaim_bgs); > spin_unlock(&fs_info->unused_bgs_lock); > btrfs_exclop_finish(fs_info); > - sb_end_write(fs_info->sb); > } > > void btrfs_reclaim_bgs(struct btrfs_fs_info *fs_info) >