On Fri, Nov 07, 2008 at 11:22:56AM +0100, Frédéric Bohé wrote: > From: Frederic Bohe <frederic.bohe@xxxxxxxx> > > Block group's checksum need to be re-calculated during the > initialization of an UNINIT'd group. This fix a race when several > threads try to allocate a new inode in an UNINIT'd group. This patch looks sane, and so I'll accept it, but there's a higher order hiding here ---- why are we initializing the block bitmap in ext4_new_inode()? Sure, *most* of the time where we create a new inode, we'll be needing to allocate a new block, but sometimes we won't (i.e., when creating a symlink, device file, socket, or a zero-length regular file). More seriously, we don't account for the potential need for an extra journal credit in all of the callers for ext4_new_inode(). Obviously this doesn't get us in trouble because we generally massively overestimate the number of journal credits we need --- but from the point of view of code simplification, maybe code block to ininitialize the block bitmap in ext4_new_inode() should be dropped entirely. We have to do the exact same check in the mballoc.c when we actually allocate blocks --- and in that case we know we'll be modifying the block bitmap, so there's no need to first initialize the block bitmap in ext4_new_inode(), only to need to request to redirty that same block bitmap in mballoc.c when we are really allocating data for the inode. Does that make sense for a future cleanup? - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
