From patchwork Mon Oct 14 10:58:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13834825 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DDC4CD16247 for ; Mon, 14 Oct 2024 11:37:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4YDRe8auf3W9gPGvw4mfS6WcApteYPOWnCg7H4VxM6g=; b=zDl8I9OInZe60zt2190FRK/m9W fR7ZshUGrFjRAFXXvQX01jYG/GK1EPHd7yLPkGhdb2sgmF2YLeU5DUHx2U2ntPen3RAnUdHAJPoIC DrmpZ+uARajsSoWLzJ2IRKXShQiqDh1PI+ccsATD3HezHBUjT+BSrX9u+MNCSEs0xHyFqy658V4wP wF1QXyTX5QBdRVPMLWl4fUw9J8ICRVykBesitd8m0FwM53piMuc7HWBk9HrqX7Ki58iBX06+pU+5D GAd+W4kpWa/jtaLj0BTwhQQzp+FL3EA/VU10/V8qa03pfAirMGisKw+nh2pzPYd0qdr15XzEw2iGA q6/Ck3LA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t0JOR-00000004xKD-0Jl1; Mon, 14 Oct 2024 11:37:43 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t0Inv-00000004nco-0UUP for linux-arm-kernel@lists.infradead.org; Mon, 14 Oct 2024 11:00:00 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 432CD1684; Mon, 14 Oct 2024 04:00:28 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D33E63F51B; Mon, 14 Oct 2024 03:59:55 -0700 (PDT) From: Ryan Roberts To: "Theodore Ts'o" , Andreas Dilger , Andrew Morton , Anshuman Khandual , Ard Biesheuvel , Catalin Marinas , David Hildenbrand , Greg Marsden , Ivan Ivanov , Kalesh Singh , Marc Zyngier , Mark Rutland , Matthias Brugger , Miroslav Benes , Will Deacon Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v1 10/57] fs/ext4: Remove PAGE_SIZE compile-time constant assumption Date: Mon, 14 Oct 2024 11:58:17 +0100 Message-ID: <20241014105912.3207374-10-ryan.roberts@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241014105912.3207374-1-ryan.roberts@arm.com> References: <20241014105514.3206191-1-ryan.roberts@arm.com> <20241014105912.3207374-1-ryan.roberts@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241014_035959_318943_93D63E8C X-CRM114-Status: GOOD ( 12.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org To prepare for supporting boot-time page size selection, refactor code to remove assumptions about PAGE_SIZE being compile-time constant. Code intended to be equivalent when compile-time page size is active. Convert CPP PAGE_SIZE conditionals to C if/else. For compile-time page size, the compiler will strip the dead part, and for boot-time page size, the condition will be evaluated at run time. Signed-off-by: Ryan Roberts --- ***NOTE*** Any confused maintainers may want to read the cover note here for context: https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/ fs/ext4/ext4.h | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 08acd152261ed..1a6dbd925024a 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2415,31 +2415,31 @@ ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize) { unsigned len = le16_to_cpu(dlen); -#if (PAGE_SIZE >= 65536) - if (len == EXT4_MAX_REC_LEN || len == 0) - return blocksize; - return (len & 65532) | ((len & 3) << 16); -#else - return len; -#endif + if (PAGE_SIZE >= 65536) { + if (len == EXT4_MAX_REC_LEN || len == 0) + return blocksize; + return (len & 65532) | ((len & 3) << 16); + } else { + return len; + } } static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize) { BUG_ON((len > blocksize) || (blocksize > (1 << 18)) || (len & 3)); -#if (PAGE_SIZE >= 65536) - if (len < 65536) + if (PAGE_SIZE >= 65536) { + if (len < 65536) + return cpu_to_le16(len); + if (len == blocksize) { + if (blocksize == 65536) + return cpu_to_le16(EXT4_MAX_REC_LEN); + else + return cpu_to_le16(0); + } + return cpu_to_le16((len & 65532) | ((len >> 16) & 3)); + } else { return cpu_to_le16(len); - if (len == blocksize) { - if (blocksize == 65536) - return cpu_to_le16(EXT4_MAX_REC_LEN); - else - return cpu_to_le16(0); } - return cpu_to_le16((len & 65532) | ((len >> 16) & 3)); -#else - return cpu_to_le16(len); -#endif } /*