This is a note to let you know that I've just added the patch titled drbd: avoid redefinition of BITS_PER_PAGE to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drbd-avoid-redefinition-of-bits_per_page.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 2630628b2dbc3fc320aafaf84836119e4e3d62f1 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx> Date: Fri, 20 Mar 2015 15:47:22 +0100 Subject: drbd: avoid redefinition of BITS_PER_PAGE From: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx> commit 2630628b2dbc3fc320aafaf84836119e4e3d62f1 upstream. Apparently we now implicitly get definitions for BITS_PER_PAGE and BITS_PER_PAGE_MASK from the pid_namespace.h Instead of renaming our defines, I chose to define only if not yet defined, but to double check the value if already defined. Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx> Signed-off-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/block/drbd/drbd_bitmap.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/block/drbd/drbd_bitmap.c +++ b/drivers/block/drbd/drbd_bitmap.c @@ -479,8 +479,14 @@ void drbd_bm_cleanup(struct drbd_device * this masks out the remaining bits. * Returns the number of bits cleared. */ +#ifndef BITS_PER_PAGE #define BITS_PER_PAGE (1UL << (PAGE_SHIFT + 3)) #define BITS_PER_PAGE_MASK (BITS_PER_PAGE - 1) +#else +# if BITS_PER_PAGE != (1UL << (PAGE_SHIFT + 3)) +# error "ambiguous BITS_PER_PAGE" +# endif +#endif #define BITS_PER_LONG_MASK (BITS_PER_LONG - 1) static int bm_clear_surplus(struct drbd_bitmap *b) { Patches currently in stable-queue which might be from lars.ellenberg@xxxxxxxxxx are queue-4.4/drbd-avoid-redefinition-of-bits_per_page.patch