On 02/21/2012 07:55 AM, Xi Wang wrote: > On Feb 20, 2012, at 6:47 PM, Eric Sandeen wrote: >> Hm this raises a few questions I think. >> >> On the one hand, making sure the kmalloc arg doesn't overflow here is >> certainly a good thing and probably the right thing to do in the short term. >> >> So I guess: >> >> Reviewed-by: Eric Sandeen <sandeen@xxxxxxxxxx> >> >> for that, to close the hole. > > Another possibility is to wait for knalloc/kmalloc_array in the -mm > tree, which is basically the non-zeroing version of kcalloc that > performs overflow checking. > >> Doesn't this also mean that a valid s_log_groups_per_flex (i.e. 31) >> will fail in this resize code? That would be an unexpected outcome. >> 2^31 groups per flex is a little crazy, but still technically valid >> according to the limits in the code. > > Or we could limit s_log_groups_per_flex/groups_per_flex to a > reasonable upper bound in ext4_fill_flex_info(), right? Depends on the "flex_bg" design intent, I guess. I don't know if the 2^31 was an intended design limit, or just a mathematical limit that based on container sizes etc... I'd have to look at the resize code more carefully but I can't imagine that it's imperative to allocate this stuff all at once. -Eric > - xi > -- 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
