From dd3678fc29d75286b57e705454bbd7e60e1b44e0 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Tue, 5 Feb 2013 09:35:43 -0800 Subject: [PATCH] Fix atomic64_* autoconf checks The SPL_AC_ATOMIC_SPINLOCK, SPL_AC_TYPE_ATOMIC64_CMPXCHG, and SPL_AC_TYPE_ATOMIC64_XCHG were all directly including the 'asm/atomic.h' header. As of Linux 3.4 this header was removed which results in a build failure. The right thing to do is include 'linux/atomic.h' however we can't safely do this because it doesn't exist in 2.6.26 kernels. Therefore, we include 'linux/fs.h' which in turn includes the correct atomic header regardless of the kernel version. When these incorrect APIs are used in ZFS the following build failure results. arc.c:791:80: warning: '__ret' may be used uninitialized in this function [-Wuninitialized] arc.c:791:1875: error: call to '__cmpxchg_wrong_size' declared with attribute error: Bad argument size for cmpxchg Since this is all Linux 2.6.24 compatibility code there's an argument to be made that it should be removed because kernels this old are not supported. However, because we're so close to a release I'm going to leave it in place for now. Signed-off-by: Brian Behlendorf Closes zfsonlinux/zfs#814 Closes zfsonlinux/zfs#1254 --- config/spl-build.m4 | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/config/spl-build.m4 b/config/spl-build.m4 index e9695de..8518404 100644 --- a/config/spl-build.m4 +++ b/config/spl-build.m4 @@ -777,7 +777,7 @@ AC_DEFUN([SPL_AC_ATOMIC_SPINLOCK], [ [enable_atomic_spinlocks=check]) SPL_LINUX_TRY_COMPILE([ - #include + #include ],[ atomic64_t *ptr __attribute__ ((unused)); ],[ @@ -820,8 +820,7 @@ dnl # AC_DEFUN([SPL_AC_TYPE_ATOMIC64_CMPXCHG], [AC_MSG_CHECKING([whether kernel defines atomic64_cmpxchg]) SPL_LINUX_TRY_COMPILE([ - #include - #include + #include ],[ atomic64_cmpxchg((atomic64_t *)NULL, 0, 0); ],[ @@ -840,7 +839,7 @@ dnl # AC_DEFUN([SPL_AC_TYPE_ATOMIC64_XCHG], [AC_MSG_CHECKING([whether kernel defines atomic64_xchg]) SPL_LINUX_TRY_COMPILE([ - #include + #include ],[ atomic64_xchg((atomic64_t *)NULL, 0); ],[ -- 1.7.10