On Dec 04, 2008 16:37 -0600, Eric Sandeen wrote: > It's too bad this wasn't caught sooner, but I wonder if maybe it's still > not too late; can we change the structure in the kernel and have newer > e2fsprogs try both the old & new? The new interface would add 32 bits > of padding to the structure; this would leave it unchanged on 64-bit > boxes so everything would continue to work. Newer e2fsprogs would try > both, so still work on older kernels. 32-bit compat would have a simple > handler, *but* this *would* break resize of ext4 on native 32-bit > machines with older e2fsprogs (the kernel would have a padded struct; > older userspace would not, and the ioctl would fail). > > How far out of "dev" are we? I'm leaning towards saying "oh well, would > have been nicer the other way" but going ahead and just putting the > compat handler into the kernel. I would be OK with changing to the "proper" struct layout. Not being able to resize with an older e2fsprogs + newer kernel isn't going to cause any serious problems (unlike e.g. not being able to mount or e2fsck "/"). If we are seriously worried about compatibility, we could add the compat handler for 32-bit kernels (should have a different IOC number anyways because of the struct size) and add some arbitrary check like: #ifdef LINUX_KERNEL_VERSION > KERNEL_VERSION(2,6,40) #warning remove this old compat code #endif Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- 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
