From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CAB5EB64DD for ; Sun, 13 Aug 2023 21:25:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231672AbjHMVZR (ORCPT ); Sun, 13 Aug 2023 17:25:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231661AbjHMVZQ (ORCPT ); Sun, 13 Aug 2023 17:25:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF4AF1700 for ; Sun, 13 Aug 2023 14:25:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 54AFF62924 for ; Sun, 13 Aug 2023 21:25:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F97CC433CA; Sun, 13 Aug 2023 21:25:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691961914; bh=GN5vOEh1YtzbzrWPL6NrR2likInKwIa/wgfGZkI4IMc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=frkbR9PPecQELONu73ErYw5a71zoMgpwxwCyScccDgjPwdBBFTVWkrpAzrzDCKXR4 2WDxDgkwQjlW7rRfApu3rgZYjYMs7XAZRdapjCLrRDCR0eplOM2TkQnySc4HyCj4eT A9gNMGqoQ7mDi9eRQYg5oxd+JKMutMUVdWbwxUGk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dusty Mabe , Christoph Hellwig , Sergey Senozhatsky , Jens Axboe Subject: [PATCH 6.4 027/206] zram: take device and not only bvec offset into account Date: Sun, 13 Aug 2023 23:16:37 +0200 Message-ID: <20230813211725.776479410@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230813211724.969019629@linuxfoundation.org> References: <20230813211724.969019629@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Christoph Hellwig commit 95848dcb9d676738411a8ff70a9704039f1b3982 upstream. Commit af8b04c63708 ("zram: simplify bvec iteration in __zram_make_request") changed the bio iteration in zram to rely on the implicit capping to page boundaries in bio_for_each_segment. But it failed to care for the fact zram not only care about the page alignment of the bio payload, but also the page alignment into the device. For buffered I/O and swap those are the same, but for direct I/O or kernel internal I/O like XFS log buffer writes they can differ. Fix this by open coding bio_for_each_segment and limiting the bvec len so that it never crosses over a page alignment boundary in the device in addition to the payload boundary already taken care of by bio_iter_iovec. Cc: stable@vger.kernel.org Fixes: af8b04c63708 ("zram: simplify bvec iteration in __zram_make_request") Reported-by: Dusty Mabe Signed-off-by: Christoph Hellwig Acked-by: Sergey Senozhatsky Link: https://lore.kernel.org/r/20230805055537.147835-1-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/zram/zram_drv.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1870,15 +1870,16 @@ static void zram_bio_discard(struct zram static void zram_bio_read(struct zram *zram, struct bio *bio) { - struct bvec_iter iter; - struct bio_vec bv; - unsigned long start_time; + unsigned long start_time = bio_start_io_acct(bio); + struct bvec_iter iter = bio->bi_iter; - start_time = bio_start_io_acct(bio); - bio_for_each_segment(bv, bio, iter) { + do { u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT; u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; + struct bio_vec bv = bio_iter_iovec(bio, iter); + + bv.bv_len = min_t(u32, bv.bv_len, PAGE_SIZE - offset); if (zram_bvec_read(zram, &bv, index, offset, bio) < 0) { atomic64_inc(&zram->stats.failed_reads); @@ -1890,22 +1891,26 @@ static void zram_bio_read(struct zram *z zram_slot_lock(zram, index); zram_accessed(zram, index); zram_slot_unlock(zram, index); - } + + bio_advance_iter_single(bio, &iter, bv.bv_len); + } while (iter.bi_size); + bio_end_io_acct(bio, start_time); bio_endio(bio); } static void zram_bio_write(struct zram *zram, struct bio *bio) { - struct bvec_iter iter; - struct bio_vec bv; - unsigned long start_time; + unsigned long start_time = bio_start_io_acct(bio); + struct bvec_iter iter = bio->bi_iter; - start_time = bio_start_io_acct(bio); - bio_for_each_segment(bv, bio, iter) { + do { u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT; u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; + struct bio_vec bv = bio_iter_iovec(bio, iter); + + bv.bv_len = min_t(u32, bv.bv_len, PAGE_SIZE - offset); if (zram_bvec_write(zram, &bv, index, offset, bio) < 0) { atomic64_inc(&zram->stats.failed_writes); @@ -1916,7 +1921,10 @@ static void zram_bio_write(struct zram * zram_slot_lock(zram, index); zram_accessed(zram, index); zram_slot_unlock(zram, index); - } + + bio_advance_iter_single(bio, &iter, bv.bv_len); + } while (iter.bi_size); + bio_end_io_acct(bio, start_time); bio_endio(bio); }