Pekka J Enberg wrote: > Hi Ted, > > On Thu, Jun 25, 2009 at 05:11:25PM -0500, Eric Sandeen wrote: >>> ecryptfs used to do kmalloc(PAGE_CACHE_SIZE) & virt_to_page on that, and >>> with SLUB + slub debug, that gave back non-aligned memory, causing >>> eventual corruption ... > > On Thu, 25 Jun 2009, Theodore Tso wrote: >> Grumble. Any chance we could add an kmem_cache option which requires >> the memory to be aligned? Otherwise we could rewrite our own sub-page >> allocator in ext4 that only handled aligned filesystem block sizes >> (i.e., 1k, 2k, 4k, etc.) but that would be really silly and be extra >> code that really should be done once at core functionality. > > We alredy have SLAB_HW_ALIGN but I wonder if this is a plain old bug in > SLUB. Christoph, Nick, don't we need something like this in the allocator? > Eric, does this fix your case? I'll test it; it'd be great if it did, I'm um, a bit ashamed at how I fixed it ;) Thanks! -Eric > Pekka > > diff --git a/mm/slub.c b/mm/slub.c > index 819f056..7cd1e69 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -2400,7 +2400,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order) > * user specified and the dynamic determination of cache line size > * on bootup. > */ > - align = calculate_alignment(flags, align, s->objsize); > + align = calculate_alignment(flags, align, size); > > /* > * SLUB stores one object immediately after another beginning from -- 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
