On Mon, 22 Mar 2010 16:39:37 +1100 Nick Piggin <npiggin@xxxxxxx> wrote:
> It's ugly and lazy that we do these default aops in case it has not
> been filled in by the filesystem.
>
> A NULL operation should always mean either: we don't support the
> operation; we don't require any action; or a bug in the filesystem,
> depending on the context.
>
> In practice, if we get rid of these fallbacks, it will be clearer
> what operations are used by a given address_space_operations struct,
> reduce branches, reduce #if BLOCK ifdefs, and should allow us to get
> rid of all the buffer_head knowledge from core mm and fs code.
I guess this is one way of waking people up.
What happens is that hundreds of bug reports land in my inbox and I get
to route them to various maintainers, most of whom don't exist, so
warnings keep on landing in my inbox. Please send a mailing address for
my invoices.
It would be more practical, more successful and quicker to hunt down
the miscreants and send them rude emails. Plus it would save you
money.
> We could add a patch like this which spits out a recipe for how to fix
> up filesystems and get them all converted quite easily.
>
> ...
>
> @@ -40,8 +40,14 @@ void do_invalidatepage(struct page *page
> void (*invalidatepage)(struct page *, unsigned long);
> invalidatepage = page->mapping->a_ops->invalidatepage;
> #ifdef CONFIG_BLOCK
> - if (!invalidatepage)
> + if (!invalidatepage) {
> + static bool warned = false;
> + if (!warned) {
> + warned = true;
> + print_symbol("address_space_operations %s missing invalidatepage method. Use block_invalidatepage.\n", (unsigned long)page->mapping->a_ops);
> + }
> invalidatepage = block_invalidatepage;
> + }
erk, I realise 80 cols can be a pain, but 165 cols is just out of
bounds. Why not
/* this fs should use block_invalidatepage() */
WARN_ON_ONCE(!invalidatepage);
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>