From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 B2F482F6571 for ; Fri, 10 Oct 2025 15:08:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760108886; cv=none; b=PZHXud2OSZnaV20oJqbNxoJ14kRr7CE8lR3P3cYJ/6/9rnGMl7pMi9tQx4vDxm1kjK8KnVG3aGnPbgNkmyRo0Id5ch2iF++GY3mq90JEbj3J65SKB4zkMeAFvCuNX80N7UYrLA1/koOcEoGUbk2z/zbv5Y6A8EaoGrTmZHhEZsI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760108886; c=relaxed/simple; bh=uGEazi1FuTCT7oIOuAdb0635RM7kubublce5V0iTWEk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=up3nOBoI11kyoZG6id70VN27GxMDbO4qvorohgRfbUc80e1o7exTtut1DYOhhZljy+tBklfDpaUIATeYTeq3ds0u+aYYjU/gDawD/7CI2vwnk2G4w1nWaix+MBGxPW5FDl4ZWd72TlyogEZa+y36W8ILB4leYyCuhb6s4Y1R2I4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=VSVTiEF/; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VSVTiEF/" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2i4g3ZgeSbL4H/JkzCmGMfKxgVXGbJNxmdmwESlUtVY=; b=VSVTiEF/8wkXsb6fTS6tQAPXaE dlyJMN4IrISqYarVk2Rblau+b5kTXoGAvS0ee+ZFGONhd7hd42CFckuvsT+IsYDVPdUwfNDYsP5KI PwiQKhe2pNU5r0odNXjdK1xpjs51AlFgQMYAvnhc7QY0KRs4mqYGbG+WQVk8zawsofP0tP41VwIKv B8fjt+ogqKBXjtAlEI12bl/R61mur+u38CVzK3oo4/Y2MWaI97774ZgCiV3akgqy+pz0IrW5Xg1R4 J9Y0mZRaukBY0MRMuLqd0sZNquWZg1Y8SDud6hiOdcjQHS/QN55sECVA8z58A6G5YVp6IFy/8HYry KeBk5CJg==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1v7Eis-0000000Cqba-2vpV; Fri, 10 Oct 2025 15:07:58 +0000 Date: Fri, 10 Oct 2025 16:07:58 +0100 From: Matthew Wilcox To: "Darrick J. Wong" Cc: Joanne Koong , Miklos Szeredi , linux-fsdevel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH] fuse: disable default bdi strictlimiting Message-ID: References: <20251008204133.2781356-1-joannelkoong@gmail.com> <20251010150113.GC6174@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-fsdevel@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: <20251010150113.GC6174@frogsfrogsfrogs> On Fri, Oct 10, 2025 at 08:01:13AM -0700, Darrick J. Wong wrote: > [cc willy in case he has opinions about dynamically changing the > pagecache order range] It's not designed for that. mapping_set_folio_order_range() accesses mapping->flags without any locking/atomicity, so we can overwrite other changes to mapping->flags, like setting AS_EIO. It really is supposed to be "the filesystem supports folios of these sizes", not "we've made some runtime change to the filesystem and now we'd preefer the MM uses folios of these sizes instead of those".