From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 46DE61170E for ; Mon, 11 Sep 2023 14:04:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDB1AC433C7; Mon, 11 Sep 2023 14:04:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694441078; bh=fGCCIdqhajnq4S+Jgv6zzCAZBpKOGioy/tSNbrH3pyY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KEjAv0gvvw19nieYb6QzlJ+zip1odaOheuDOxTIotlUzpNhTHdnvADrB9we5ywo6v /nugZmAA7ekwDXvYUmuopoI621KkIpKiA+5S7+2RGlveWkpiI0EYqIFxHmVTgNbAZO pzNgIDrcdK+vuJa3B95ixG9cA9NvBvQ3rk1zTw10= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Hellwig , Jens Axboe , Sasha Levin Subject: [PATCH 6.5 261/739] block: dont allow enabling a cache on devices that dont support it Date: Mon, 11 Sep 2023 15:41:00 +0200 Message-ID: <20230911134658.434582650@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134650.921299741@linuxfoundation.org> References: <20230911134650.921299741@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christoph Hellwig [ Upstream commit 43c9835b144c7ce29efe142d662529662a9eb376 ] Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC flag on devices that never claimed the capability. Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by blk_queue_write_cache and guards re-enabling the cache through sysfs. Note that any rescan that calls blk_queue_write_cache will still re-enable the write cache as in the current code. Fixes: 93e9d8e836cb ("block: add ability to flag write back caching on a device") Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-settings.c | 7 +++++-- block/blk-sysfs.c | 11 +++++++---- include/linux/blkdev.h | 1 + 3 files changed, 13 insertions(+), 6 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index 4dd59059b788e..0046b447268f9 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -830,10 +830,13 @@ EXPORT_SYMBOL(blk_set_queue_depth); */ void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua) { - if (wc) + if (wc) { + blk_queue_flag_set(QUEUE_FLAG_HW_WC, q); blk_queue_flag_set(QUEUE_FLAG_WC, q); - else + } else { + blk_queue_flag_clear(QUEUE_FLAG_HW_WC, q); blk_queue_flag_clear(QUEUE_FLAG_WC, q); + } if (fua) blk_queue_flag_set(QUEUE_FLAG_FUA, q); else diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 0cde6598fb2f4..63e4812623361 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -449,13 +449,16 @@ static ssize_t queue_wc_show(struct request_queue *q, char *page) static ssize_t queue_wc_store(struct request_queue *q, const char *page, size_t count) { - if (!strncmp(page, "write back", 10)) + if (!strncmp(page, "write back", 10)) { + if (!test_bit(QUEUE_FLAG_HW_WC, &q->queue_flags)) + return -EINVAL; blk_queue_flag_set(QUEUE_FLAG_WC, q); - else if (!strncmp(page, "write through", 13) || - !strncmp(page, "none", 4)) + } else if (!strncmp(page, "write through", 13) || + !strncmp(page, "none", 4)) { blk_queue_flag_clear(QUEUE_FLAG_WC, q); - else + } else { return -EINVAL; + } return count; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 87d94be7825af..56f7f79137921 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -538,6 +538,7 @@ struct request_queue { #define QUEUE_FLAG_ADD_RANDOM 10 /* Contributes to random pool */ #define QUEUE_FLAG_SYNCHRONOUS 11 /* always completes in submit context */ #define QUEUE_FLAG_SAME_FORCE 12 /* force complete on same CPU */ +#define QUEUE_FLAG_HW_WC 18 /* Write back caching supported */ #define QUEUE_FLAG_INIT_DONE 14 /* queue is initialized */ #define QUEUE_FLAG_STABLE_WRITES 15 /* don't modify blks until WB is done */ #define QUEUE_FLAG_POLL 16 /* IO polling enabled if set */ -- 2.40.1