linux-kernel - Re: [PATCH 7/8] Btrfs: use REQ_CGROUP_PUNT for worker thread submitted bios

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190614151524.GZ3563@twin.jikos.cz>
Date:   Fri, 14 Jun 2019 17:15:24 +0200
From:   David Sterba <dsterba@...e.cz>
To:     Tejun Heo <tj@...nel.org>
Cc:     dsterba@...e.com, clm@...com, josef@...icpanda.com,
        axboe@...nel.dk, jack@...e.cz, linux-btrfs@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-block@...r.kernel.org,
        kernel-team@...com
Subject: Re: [PATCH 7/8] Btrfs: use REQ_CGROUP_PUNT for worker thread
 submitted bios

On Thu, Jun 13, 2019 at 05:33:49PM -0700, Tejun Heo wrote:
> @@ -1251,12 +1258,29 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
>  		 * to unlock it.
>  		 */
>  		if (locked_page) {
> +			/*
> +			 * Depending on the compressibility, the pages
> +			 * might or might not go through async.  We want
> +			 * all of them to be accounted against @wbc once.
> +			 * Let's do it here before the paths diverge.  wbc
> +			 * accounting is used only for foreign writeback
> +			 * detection and doesn't need full accuracy.  Just
> +			 * account the whole thing against the first page.
> +			 */
> +			wbc_account_io(wbc, locked_page, cur_end - start);
>  			async_chunk[i].locked_page = locked_page;
>  			locked_page = NULL;
>  		} else {
>  			async_chunk[i].locked_page = NULL;
>  		}
>  
> +		if (blkcg_css != blkcg_root_css) {
> +			css_get(blkcg_css);

fs/btrfs/inode.c: In function ‘cow_file_range_async’:
fs/btrfs/inode.c:1278:4: error: implicit declaration of function ‘css_get’; did you mean ‘css_put’? [-Werror=implicit-function-declaration]
 1278 |    css_get(blkcg_css);
      |    ^~~~~~~
      |    css_put

I don't have CONFIG_CGROUPS enabled in the testing kernel so this probably
needs a wrapper so the ifdef is not in the middle of the function.