On 07/18/2012 11:11 PM, Christoph Hellwig wrote: > 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. Now I got it, thanks for the teaching. Thanks, -Jeff > > _______________________________________________ > xfs mailing list > xfs@xxxxxxxxxxx > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
