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 7DA3B43BDCB for ; Wed, 29 Jul 2026 11:44:12 +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=1785325456; cv=none; b=ZogBU9vxxydJrkMm+Wovc5Op/LOtJwlNlrW7C1QZf9dVlqSJmwoFg2XNdhAtGYocXHP4bghIa4Ttt3Tnxpg4OJBMuPAewTQKWXNmvBv/IkPOBbFQetltsSxWkpv9sD6E6HvEs1SCDJITine1skYp3PkkeKA6l07NXpjQu1uv8MY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785325456; c=relaxed/simple; bh=OD59xc9cM470EYUQWUnsATjpkpNQrCJ5nvBsfwKejJw=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=Y8+NCSL4rhJuPz/eyIH7t9ShT5rxBaLJ7wCN87Cz4NHFgR2bCgGv2ugnc9x5nqwoGDIMJ1nzZOl+RMZcvzsHBvU1lIfbR9pUkoZddeFQrDDiBZTi4W5mKkw+ghiWKPxgMWHt6nix4ct6c0xWRWijbwldfQip4/gQLka+a2C7ERY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LscUuNsH; 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="LscUuNsH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B44831F000E9; Wed, 29 Jul 2026 11:44:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785325449; bh=4+Tca2IcSPPZfQSRkigbJtpn7Wv2qQKHxhyLWS7+PRU=; h=Date:Cc:Subject:To:References:From:In-Reply-To; b=LscUuNsHEOIIOnLYC/EMVAQAcHLC3ylAAbaW0bomLPhd2F3vEa3MXrazHPUCy0vGD 8vzZMW8dSrXMqGeBgmzPQsMI9QPtmqjgsLfi+/wrrrmfqigfrJwapNhh8AikUxQOEx EwJgwX/sgggb+K4JupWpo5or15d7goxob0QVSvAgkQdOEl+bYOl3ZDVUw0Jk3Cwyvj kGwKudFD7tmC4peAWbPK6d5xvcz2x/3G57Xi+zFsTqMesCdHnT/EaB3KjjdDTFhpQ2 8JQ2XHlmW2j26dO7Ajzgm3Y3nUrdQJxFGelD1gI45J1vsCkBhzgWj21zaDzBwR7/b9 RKa8Aw0hgH6Dg== Message-ID: Date: Wed, 29 Jul 2026 19:44:06 +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, Daeho Jeong Subject: Re: [f2fs-dev] [PATCH v5] f2fs: support dynamic reserve/release for device aliasing To: Daeho Jeong , linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com References: <20260723202008.2581659-1-daeho43@gmail.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20260723202008.2581659-1-daeho43@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/24/26 04:20, Daeho Jeong wrote: > From: Daeho Jeong > > This patch adds a dynamic management feature to the existing device > aliasing functionality. It allows users to dynamically reserve or > release specific devices from the filesystem's free pool at runtime > through new ioctls. > > To support this, three new ioctls are introduced: > - F2FS_IOC_RESERVE_DEV_ALIAS: This reclaims the space occupied by a > device aliasing file. It first performs a capacity check, resets GC > victim information for the target range, marks the segments as in-use > to prevent new allocations, and then triggers GC to migrate existing > valid data out of the range. Finally, it reserves these blocks in the > SIT to effectively exclude the device from the usable capacity. > > - F2FS_IOC_RELEASE_DEV_ALIAS: This releases the reserved space of a > previously reserved device aliasing file. It truncates the blocks > associated with the file, which makes them available for general > filesystem allocation again. > > - F2FS_IOC_GET_DEV_ALIAS_STATUS: This retrieves the current aliasing > status of a device aliasing file, returning whether the file is > released (inactive alias) or reserved (active alias, with blocks > fully allocated on the device). Hi Daeho, BTW, could you please consider to do some coverage test to prevent from suffering potential corruption. e.g.: 1. call ioctls in low storage environment 2. race w/ checkpoint={disable,enable} 3. injecting faults in new ioctls + random shutdown To verify if filesystem or device alias file is corrupted, it needs to call fsck after the testcase, and find a way to verify whether device alias status is as expected or not. Please sharing your thoughts about this. :) Thanks,