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 CE9A742049D; Mon, 3 Aug 2026 20:09:20 +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=1785787762; cv=none; b=jHHHgIOaJ3qTE2oFOdNK35B7TQUmXzSBQP9txyVPFa8IQHfpIgQz7cOaYJ0Grl0/LF1aIz3xp1+BuXUE1vLeDsOQBLVrtIgYTBeB5GrfZQ/GTupJXDSfenGJafwgbc8vCJWnCGnMGb1SKpjjv1VYAFHEAcu0dOHbAAxLFoIX7Vc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785787762; c=relaxed/simple; bh=vvBJkYxxOMUdxPQvRNWFjbdqDYu6ibnNDulSFIkVvYI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UVKn2kZhP3w+W4SB9x5LGfxNDTGVNlbnGSe6klk3/pV3qCLaI3e6GQ6LZpbvW74+r/WEGACe7r/RWk4/5UbyW9NTTQzQXtjF1zwDhXY+3Ocz4NGaPj4EJhJzBoxBfS3yCmHkR+NMJudjyTnz/5CmUFMeUwrOMTq9NJKNXcJmn0M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=X9Rcboru; 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="X9Rcboru" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D857C1F00A3E; Mon, 3 Aug 2026 20:09:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785787760; bh=1i5PkmN5JfVODQHHHlqnvp3yzz22XTSFm/6ynxgAmcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=X9RcboruTw2IJHtaxvhR10PRk1ivwDxJxgwv0N+FSASdMBEoiY9rL9eHwfZjRCyyv XCSWXvwIHQRPvTl9ChdpPWuxi3x2M4LdSXGowQrRtaCtam9GKVfeg6pJ5ReoMtB7w0 H3I4zcCN2Z+yLIPv/9gncxf6GWL0cdTqL8bgJ0ZppzGa5MqIR9eco+VGdoz/ZeoYK6 Qphx9pdWt2eHMwaWKK78ODOc5OQhG53xHHsPoYrnhen5JWgdbM8g6gbMADxeG8pKYy OtjgViViXYtZGEKEBOc1PzRQL3NiOBscsTcbZg6IzwsDAMZ2qpOpQ7Ahgp9MFzZMcf aK0G+P1zuu2Gw== From: Andrey Albershteyn To: linux-xfs@vger.kernel.org, fsverity@lists.linux.dev, linux-fsdevel@vger.kernel.org, ebiggers@kernel.org Cc: Andrey Albershteyn , hch@lst.de, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-btrfs@vger.kernel.org, djwong@kernel.org Subject: [PATCH v14 05/21] fsverity: improve flushing performance of fsverity_fill_zerohash Date: Mon, 3 Aug 2026 22:07:55 +0200 Message-ID: <20260803200820.393203-6-aalbersh@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260803200820.393203-1-aalbersh@kernel.org> References: <20260803200820.393203-1-aalbersh@kernel.org> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The current version calls flush_dcache_folio(), in memcpy_to_folio(), to flush whole folio on every digest (which is 128 for 4k) on the HIGHMEM systems. Open code folio mapping and flushing to copy all digests at once. Reported-by: Eric Biggers Link: https://lore.kernel.org/linux-fsdevel/20260401222717.GH2466@quark/ Signed-off-by: Andrey Albershteyn --- fs/verity/pagecache.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/fs/verity/pagecache.c b/fs/verity/pagecache.c index 9d82e6b74ba1..911207dc0ef7 100644 --- a/fs/verity/pagecache.c +++ b/fs/verity/pagecache.c @@ -68,14 +68,38 @@ EXPORT_SYMBOL_GPL(generic_readahead_merkle_tree); void fsverity_fill_zerohash(struct folio *folio, size_t offset, size_t len, struct fsverity_info *vi) { - size_t off = offset; + size_t off; WARN_ON_ONCE(!IS_ALIGNED(offset, vi->tree_params.digest_size)); WARN_ON_ONCE(!IS_ALIGNED(len, vi->tree_params.digest_size)); +#ifdef CONFIG_HIGHMEM + WARN_ON_ONCE(offset + len > folio_size(folio)); - for (; off < (offset + len); off += vi->tree_params.digest_size) + do { + void *vaddr = kmap_local_folio(folio, offset); + void *to = vaddr; + + off = len; + + if (folio_test_partial_kmap(folio) && + off > PAGE_SIZE - offset_in_page(offset)) + off = PAGE_SIZE - offset_in_page(offset); + for (; to < (vaddr + off); to += vi->tree_params.digest_size) + memcpy(to, vi->tree_params.zero_digest, + vi->tree_params.digest_size); + kunmap_local(vaddr); + + offset += off; + len -= off; + } while (len > 0); + + flush_dcache_folio(folio); +#else + for (off = offset; off < (offset + len); + off += vi->tree_params.digest_size) memcpy_to_folio(folio, off, vi->tree_params.zero_digest, vi->tree_params.digest_size); +#endif } EXPORT_SYMBOL_GPL(fsverity_fill_zerohash); -- 2.54.0