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 6886140315B for ; Mon, 29 Jun 2026 16:37:35 +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=1782751056; cv=none; b=RNpYOkBijqlmIX+Lp9Af0GUCmyIqZ8dwBOLC0byxnIJE3TmkVwfdPLHCtF6Qk5hZeFycKgbHWXB132CEK0A3gWSbeB5kYpCWgDetAYFDeCcQc46Az1ajwUO2AzF2MmqIrKnlIkTTx3BAWpv4XtxLYSU4vOS0h4rwpWoJuz9wA4k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782751056; c=relaxed/simple; bh=Ly2eM5usbijVbR3s3cQl200vfsIvIuCXQcLe7fOGQnM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SmPmySAFtvpTlsIJgiJ4po8yKZMr5nGNzGxE3leDJ26CHkRlZ5o9QUjtdZHWvm7KfVnLU4oWYitzmSfJlLz8wo4B1pWnqWhuOV9zvIgsB4zVasvknmDgHDAi2Wveor5BH1cJoPaCgvsM5iEtqFPGAXQCojXwK4TdFuD05FwEQ08= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a69pGlB4; 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="a69pGlB4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDAED1F000E9; Mon, 29 Jun 2026 16:37:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782751055; bh=7JHewKYa5/FTTPDRStSCJXtjBGuHptHfKbTCR8wXYao=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=a69pGlB4jKPrTsc+I/siJAuw8v/xiP50xITuIxUZv7uXRzugRpCea1B0Ft9FLa01J 3aSWZqW7Ix0lmLmF3NF9XVKH/1McKzT2BoQQAQiVeyMUYdKl0rMIaY9LVunZjUPSxZ vIO3uTlKlAPO84EPoNMo0wWq4aRtDwV4G4evF3ij79hy3HQSLbwMghZRdKc0LRNDcX 56WWWmKBqEMjtzuSrAQnAv+2IIrm5JiUtd+fNzROy3jU6ie1bTwl2kvgfAmxFK2V6A HJiVmvcdfYS6T/oH/9gABsW75rT/07LcWgNF2fIdmju9ZtavTELMm7wgcfr7rQ1Lds PDY7gq6Ns8hYQ== Date: Tue, 30 Jun 2026 00:37:29 +0800 From: Zorro Lang To: Jan Prusakowski Cc: Christoph Hellwig , fstests@vger.kernel.org, jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [PATCH] generic/064: allow 50 extents on F2FS after fcollapse Message-ID: Mail-Followup-To: Jan Prusakowski , Christoph Hellwig , fstests@vger.kernel.org, jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net References: <20260622070438.1542638-1-jprusakowski@google.com> Precedence: bulk X-Mailing-List: fstests@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jun 24, 2026 at 12:46:01AM -0700, Christoph Hellwig wrote: > On Mon, Jun 22, 2026 at 07:04:38AM +0000, Jan Prusakowski wrote: > > On F2FS, generic/064 fails with "extents mismatched before = 1 after = > > 50" following multiple fcollapse (collapse range) operations. > > > > To ensure crash consistency and checkpoint integrity, F2FS forbids > > in-place SSR (Summary Standalone Replacement) overwrites on valid > > checkpointed blocks. When collapse range shifts blocks, F2FS allocates > > new data pages in LFS mode (out-of-place log writes). As a result, > > sequential collapse range calls rewrite shifted blocks at new log > > locations, intentionally leaving the file with 50 extents. > > This sounds odd. The test allocates a contigous range and then just does > insert/collapse on it, which should not lead to any new data block > allocations. Given that the test works fine on zoned XFS and btrfs > with strict out of place write policies we know it does not require > overwriting blocks to work as well. > > So I think something is fishy in f2fs if needs to allocate data blocks > here. I have the same question with Christoph. Shouldn't fcollapse in F2FS just remap the metadata instead of allocating new data blocks? >