Re: [patch][rfc] possible lock_page fix for Andrea's nopage vs invalidate race?

[Nick Piggin <nickpiggin@yahoo.com.au>]

Nick Piggin wrote:
> Hugh Dickins wrote:

>> I suppose this is quite efficient, but I find it confusing.
>> We have lots and lots of drivers already setting vm_flags in their
>> mmap methods, now you add an alternative way of doing the same thing.
>> Can't you just set VM_NOPAGE_LOCKED in the relevant mmap methods?
>> Or did you try it that way and it worked out messy?
> 
> 
> Generic pagecache doesn't have an mmap method, which is where
> I stopped looking. I guess you could add the |= to filemap_nopage,
> but that's much uglier.
> 
> I don't find it at all confusing, just maybe a bit of a violation
> because the structure is technically only for "ops".

Hmm, I guess adding a new mmap method solely to set that flag
would actually be cleaner. And it would allow any filesystems
that override .nopage bug end up calling filemap_nopage could
equivalently override their mmap but still call filemap_mmap.

Yes that might be nicer.

-- 
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com 

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>