On Thu, 2011-01-20 at 13:55 +0800, Andrew Morton wrote: > On Thu, 20 Jan 2011 13:38:18 +0800 Shaohua Li <shaohua.li@xxxxxxxxx> wrote: > > > > ext2, minix and probably others create an address_space for each > > > directory. Heaven knows what xfs does (for example). > > yes, this is for one directiory, but the all files's metadata are in > > block_dev address_space. > > I thought you mean there are several block_dev address_space like > > address_space in some filesystems, which doesn't fit well in my > > implementation. for ext like filesystem, there is only one > > address_space. for filesystems with several address_space, my proposal > > is map them to a virtual big address_space in the new ioctls. > > ext2 and minixfs (and I think sysv and ufs) have a separate > address_space for each directory. I don't see how those can be > represented with a single "virtual big address_space" - we also need > identifiers in there so each directory's address_space can be created > and appropriately populated. Oh, I misunderstand your comments. you are right, the ioctl methods don't work for ext2. the dir's address_space can't be readahead either. Looks we could only do the metadata readahead in filesystem specific way. Thanks, Shaohua -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html