Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 1 Mar 2022 15:22:09 +0100
From:   David Sterba <dsterba@suse.cz>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Jens Axboe <axboe@kernel.dk>, Coly Li <colyli@suse.de>,
        Mike Snitzer <snitzer@redhat.com>, Song Liu <song@kernel.org>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Josef Bacik <josef@toxicpanda.com>,
        David Sterba <dsterba@suse.com>,
        Phillip Lougher <phillip@squashfs.org.uk>,
        linux-block@vger.kernel.org, dm-devel@redhat.com,
        linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org,
        linux-raid@vger.kernel.org, target-devel@vger.kernel.org,
        linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 1/5] btrfs: simplify ->flush_bio handling
Message-ID: <20220301142209.GN12643@suse.cz>
Reply-To: dsterba@suse.cz
Mail-Followup-To: dsterba@suse.cz, Christoph Hellwig <hch@lst.de>,
        Jens Axboe <axboe@kernel.dk>, Coly Li <colyli@suse.de>,
        Mike Snitzer <snitzer@redhat.com>, Song Liu <song@kernel.org>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Josef Bacik <josef@toxicpanda.com>, David Sterba <dsterba@suse.com>,
        Phillip Lougher <phillip@squashfs.org.uk>,
        linux-block@vger.kernel.org, dm-devel@redhat.com,
        linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org,
        linux-raid@vger.kernel.org, target-devel@vger.kernel.org,
        linux-btrfs@vger.kernel.org
References: <20220301084552.880256-1-hch@lst.de>
 <20220301084552.880256-2-hch@lst.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220301084552.880256-2-hch@lst.de>
User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12)
Precedence: bulk

On Tue, Mar 01, 2022 at 10:45:48AM +0200, Christoph Hellwig wrote:
> @@ -6962,16 +6961,6 @@ struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
>  	if (!dev)
>  		return ERR_PTR(-ENOMEM);
>  
> -	/*
> -	 * Preallocate a bio that's always going to be used for flushing device
> -	 * barriers and matches the device lifespan
> -	 */
> -	dev->flush_bio = bio_kmalloc(GFP_KERNEL, 0);
> -	if (!dev->flush_bio) {
> -		kfree(dev);
> -		return ERR_PTR(-ENOMEM);
> -	}
> -
>  	INIT_LIST_HEAD(&dev->dev_list);
>  	INIT_LIST_HEAD(&dev->dev_alloc_list);
>  	INIT_LIST_HEAD(&dev->post_commit_list);
> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
> index 005c9e2a491a1..9af7b6211920c 100644
> --- a/fs/btrfs/volumes.h
> +++ b/fs/btrfs/volumes.h
> @@ -117,7 +117,7 @@ struct btrfs_device {
>  	u64 commit_bytes_used;
>  
>  	/* for sending down flush barriers */
> -	struct bio *flush_bio;

Please add this comment to the struct member declaration:

	/* Bio used for flushing device barriers */

> +	struct bio flush_bio;

Otherwise

Reviewed-by: David Sterba <dsterba@suse.com>

Thanks.