On Fri, Nov 15, 2013 at 02:42:08PM +0100, Geert Uytterhoeven wrote: > On Fri, Nov 15, 2013 at 2:40 PM, Chris Mason <chris.ma...@fusionio.com> wrote: > > Quoting Chris Mason (2013-11-15 07:21:31) > >> Quoting Heiko Carstens (2013-11-15 06:32:16) > >> > On Thu, Nov 14, 2013 at 12:19:52PM -0500, Chris Mason wrote: > >> > > Hi Linus, > >> > > > >> > > Please pull my for-linus branch: > >> > > > >> > > git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git > >> > > for-linus > >> > > > >> > > This is our usual merge window set of bug fixes, performance > >> > > improvements and cleanups. Miao Xie has some really nice optimizations > >> > > for writeback. > >> > > > >> > > Josef also expanded our sanity checks quite a bit; these make up a big > >> > > chunk of the new lines. > >> > > >> > Hmm.. b19e68439375 "btrfs: Remove redundant local zero structure" > >> > seems to > >> > use the empty_zero_page incorrectly and causes this compile warning on > >> > s390: > >> > > >> > CC fs/btrfs/ioctl.o > >> > fs/btrfs/ioctl.c: In function 'btrfs_is_empty_uuid': > >> > fs/btrfs/ioctl.c:372:2: warning: passing argument 2 of 'memcmp' makes > >> > pointer from > >> > integer without a cast [enabled by default] > >> > return !memcmp(uuid, empty_zero_page, BTRFS_UUID_SIZE); > >> > ^ > >> > > >> > In fact there seem to be two more incorrect usages in the kernel. The > >> > patch > >> > below is not really tested. > >> > >> Thanks Heiko, > >> > >> I'll make a new pull with the btrfs part of this. > > > > Or something slightly different ;) > > > > BUG: unable to handle kernel paging request at 0000000001ba6000 > > IP: [<ffffffff812b3656>] memcmp+0xf/0x22 > > I was just going to comment that > > + const void *zero_page = (const void *) page_to_phys(ZERO_PAGE(0)); > > won't fly. You can't just cast a physical address to "void *".
Ouch.. I think that only works on s390 because we have a 1:1 mapping for physical to virtual addresses in kernel space due to our split address spaces. So for btrfs and kvm it should be page_to_virt(), and for the dma_map_single() case I have no idea. :) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
