linux-kernel - Re: [PATCH] jbd2: avoid the concurrent data writeback

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: <20101115112732.GA15953@infradead.org>
Date:	Mon, 15 Nov 2010 06:27:32 -0500
From:	Christoph Hellwig <hch@...radead.org>
To:	Feng Tang <feng.tang@...el.com>
Cc:	"Wu, Fengguang" <fengguang.wu@...el.com>,
	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>,
	"linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] jbd2: avoid the concurrent data writeback

On Mon, Nov 15, 2010 at 05:59:43PM +0800, Feng Tang wrote:
> + *
> + * Sometimes when this get called, the host inode may be under data
> + * syncing initiated by flush thread(especially for a large file), and 
> + * in such situation, we should skip this path of writeback
>   */
>  static int journal_submit_inode_data_buffers(struct address_space *mapping)
>  {
> @@ -181,6 +185,13 @@ static int journal_submit_inode_data_buffers(struct address_space *mapping)
>  		.range_end = i_size_read(mapping->host),
>  	};
>  
> +	spin_lock(&inode_lock);
> +	if (mapping->host->i_state & I_SYNC) {
> +		spin_unlock(&inode_lock);
> +		return 0;
> +	}
> +	spin_unlock(&inode_lock);
> +

inode_lock is not exported to modules, and that's for a pretty good
reason.  I think you want to change this code at a higher level to not
compete with the flusher threads at all.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/