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 73840134CD9; Fri, 2 Feb 2024 18:40:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899239; cv=none; b=i+UrBTY3QgDqoNflMolmEeR2DW0iIgPDPjBCXtATNPVkwCRxM6/h7xL1M1jdo64Hun4AR1d1xxtUy6OTQrxvlNbZBFaMHFKX/3HEWVY3x3/Ep+daD6vp7ok3jRj/wCUPNo7LIpQDquLJ/jxIqi+h+gNWBKEqzO9znIgH0iOcakk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899239; c=relaxed/simple; bh=eZMy0rsC1O2myoC9DEfCEzi+FKFhOhwY9HAwgwyPxHA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WKACk4P78sfPl3gvg33cVUUxhYTjlQ7+6Ry5gJ45WfYZrfqtGeenBY6TjQl6dh2H8hV0SQXZYg5XAIBJkL8y0UP33qduXQ+j+YXmC9X2RujJmCavSU6oa9wuL+x27OJ4o/ZyglqBsv13hk9jqKKi291GCvtNsnfdJr7at0Pbz10= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oRaBO2mb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oRaBO2mb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 667BCC433C7; Fri, 2 Feb 2024 18:40:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706899239; bh=eZMy0rsC1O2myoC9DEfCEzi+FKFhOhwY9HAwgwyPxHA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oRaBO2mb9Q3flbCINhKaYt3prpJ5bFzYA/wzNdkfNHmWcTVTcVO5PZKNv6Nf74ze/ EMtsnSnDSe/T6uNJjZ0i9jfUPfXy6tAKagnvQZgq22n2i8hAQpQrKg6g4GK/zHuOW7 S796TBjdde7W6IFB8ioMSWwm2PBJ++v84uxcjS9xzsVEC6yDhWKaUxq8UJBnsZmsp2 8nNVXvs5B9Mq7sjgUcqkxKOcaX3A/7C6RhaVnLS4VYR6MCniVFqAbO0HLH4TdKy3O7 nijFTRgTbnBJHlnPVSfJIRiZUAsV/BYS3NizQBuuE2It3isnJWrgJCyelBAMlczO4J g5oSixiS0ZV0Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Maksim Kiselev , Christoph Hellwig , Jens Axboe , Sasha Levin , justin@coraid.com, linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 15/21] aoe: avoid potential deadlock at set_capacity Date: Fri, 2 Feb 2024 13:40:02 -0500 Message-ID: <20240202184015.540966-15-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240202184015.540966-1-sashal@kernel.org> References: <20240202184015.540966-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.15 Content-Transfer-Encoding: 8bit From: Maksim Kiselev [ Upstream commit e169bd4fb2b36c4b2bee63c35c740c85daeb2e86 ] Move set_capacity() outside of the section procected by (&d->lock). To avoid possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- [1] lock(&bdev->bd_size_lock); local_irq_disable(); [2] lock(&d->lock); [3] lock(&bdev->bd_size_lock); [4] lock(&d->lock); *** DEADLOCK *** Where [1](&bdev->bd_size_lock) hold by zram_add()->set_capacity(). [2]lock(&d->lock) hold by aoeblk_gdalloc(). And aoeblk_gdalloc() is trying to acquire [3](&bdev->bd_size_lock) at set_capacity() call. In this situation an attempt to acquire [4]lock(&d->lock) from aoecmd_cfg_rsp() will lead to deadlock. So the simplest solution is breaking lock dependency [2](&d->lock) -> [3](&bdev->bd_size_lock) by moving set_capacity() outside. Signed-off-by: Maksim Kiselev Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240124072436.3745720-2-bigunclemax@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/aoe/aoeblk.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c index cf6883756155..37eff1c97451 100644 --- a/drivers/block/aoe/aoeblk.c +++ b/drivers/block/aoe/aoeblk.c @@ -333,6 +333,7 @@ aoeblk_gdalloc(void *vp) struct gendisk *gd; mempool_t *mp; struct blk_mq_tag_set *set; + sector_t ssize; ulong flags; int late = 0; int err; @@ -395,7 +396,7 @@ aoeblk_gdalloc(void *vp) gd->minors = AOE_PARTITIONS; gd->fops = &aoe_bdops; gd->private_data = d; - set_capacity(gd, d->ssize); + ssize = d->ssize; snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d", d->aoemajor, d->aoeminor); @@ -404,6 +405,8 @@ aoeblk_gdalloc(void *vp) spin_unlock_irqrestore(&d->lock, flags); + set_capacity(gd, ssize); + err = device_add_disk(NULL, gd, aoe_attr_groups); if (err) goto out_disk_cleanup; -- 2.43.0