From: Christoph Hellwig <hch@infradead.org>
To: Jeff Liu <jeff.liu@oracle.com>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH] xfs: Add readpage() check up for mmap file at xfs_file_mmap()
Date: Wed, 18 Jul 2012 11:11:48 -0400 [thread overview]
Message-ID: <20120718151148.GA17374@infradead.org> (raw)
In-Reply-To: <5006CC80.3070208@oracle.com>
On Wed, Jul 18, 2012 at 10:47:28PM +0800, Jeff Liu wrote:
> Hello,
>
> When studying XFS code, I found xfs_file_mmap() does not check whether a specific file has readpage() or not.
> Actually, I have no idea of which kind of file does not supply page reading function, but Btrfs/Ext4
> as well as generic_file_mmap() all do this check at first, do we also need a defense here?
It's not needed. In generic_file_mmap it might make a little sense as
any filesystem could use it, but even there's it's questionable because
->readpage is the only way to actually supposed mmap when using
generic_file_mmap.
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next prev parent reply other threads:[~2012-07-18 15:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-18 14:47 [PATCH] xfs: Add readpage() check up for mmap file at xfs_file_mmap() Jeff Liu
2012-07-18 15:11 ` Christoph Hellwig [this message]
2012-07-19 2:59 ` Jeff Liu
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