From: Christoph Hellwig <hch@infradead.org>
To: Jan Kara <jack@suse.cz>
Cc: LKML <linux-kernel@vger.kernel.org>,
Christoph Hellwig <hch@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/3] bdi: Use parent filesystem BDI for inodes not capable of writeback
Date: Tue, 27 Jul 2010 13:09:03 -0400 [thread overview]
Message-ID: <20100727170903.GA9034@infradead.org> (raw)
In-Reply-To: <1280250301-17603-2-git-send-email-jack@suse.cz>
> +static struct backing_dev_info *inode_to_bdi(struct inode *inode)
> +{
> + struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
> +
> + /*
> + * This is a hack but it solves a problem with device inode
> + * for e.g. /dev/zero getting dirty (via touch or so) and confusing
> + * writeback code. In such cases we return the "parent" filesystem's
> + * bdi.
> + */
> + if (bdi_cap_writeback_dirty(bdi))
> + return bdi;
> + return inode->i_sb->s_bdi;
When do we ever have a writeback-capable bdi that sits inside another
filesystem? I think just always using inode->i_sb->s_bdi is the right
thing here.
And btw, having a BDI_CAP_NO_WRITEBACK instead of a BDI_CAP_WRITEBACK
is rather dumb, we'd better fix it up while we're at it.
next prev parent reply other threads:[~2010-07-27 17:09 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-27 17:04 [PATCH 0/3] Fix warnings in __mark_inode_dirty Jan Kara
2010-07-27 17:04 ` [PATCH 1/3] bdi: Use parent filesystem BDI for inodes not capable of writeback Jan Kara
2010-07-27 17:09 ` Christoph Hellwig [this message]
2010-07-27 17:24 ` Jan Kara
2010-07-27 17:27 ` Christoph Hellwig
2010-07-27 18:01 ` Jan Kara
2010-07-27 20:12 ` Christoph Hellwig
2010-07-27 20:21 ` Christoph Hellwig
2010-07-27 20:44 ` Jan Kara
2010-07-27 20:46 ` Christoph Hellwig
2010-07-29 8:12 ` Christoph Hellwig
2010-07-29 12:17 ` Jan Kara
2010-07-27 17:05 ` [PATCH 2/3] char: Mark /dev/zero and /dev/kmem as " Jan Kara
2010-07-27 17:05 ` [PATCH 3/3] bdi: Initialize noop_backing_dev_info properly Jan Kara
2010-07-27 17:09 ` Christoph Hellwig
2010-07-27 17:17 ` Jan Kara
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