diff options
Diffstat (limited to 'config/kernel-blk-queue-flush.m4')
| -rw-r--r-- | config/kernel-blk-queue-flush.m4 | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/config/kernel-blk-queue-flush.m4 b/config/kernel-blk-queue-flush.m4 new file mode 100644 index 000000000..06561edf6 --- /dev/null +++ b/config/kernel-blk-queue-flush.m4 @@ -0,0 +1,46 @@ +dnl # +dnl # 2.6.36 API change +dnl # In 2.6.36 kernels the blk_queue_ordered() interface has been +dnl # replaced by the simpler blk_queue_flush(). However, while the +dnl # old interface was available to all the new one is GPL-only. +dnl # Thus in addition to detecting if this function is available +dnl # we determine if it is GPL-only. If the GPL-only interface is +dnl # there we implement our own compatibility function, otherwise +dnl # we use the function. The hope is that long term this function +dnl # will be opened up. +dnl # +AC_DEFUN([ZFS_AC_KERNEL_BLK_QUEUE_FLUSH], [ + AC_MSG_CHECKING([whether blk_queue_flush() is available]) + tmp_flags="$EXTRA_KCFLAGS" + EXTRA_KCFLAGS="-Wno-unused-but-set-variable" + ZFS_LINUX_TRY_COMPILE([ + #include <linux/blkdev.h> + ],[ + struct request_queue *q = NULL; + (void) blk_queue_flush(q, REQ_FLUSH); + ],[ + AC_MSG_RESULT(yes) + AC_DEFINE(HAVE_BLK_QUEUE_FLUSH, 1, + [blk_queue_flush() is available]) + ],[ + AC_MSG_RESULT(no) + ]) + + AC_MSG_CHECKING([whether blk_queue_flush() is GPL-only]) + ZFS_LINUX_TRY_COMPILE([ + #include <linux/module.h> + #include <linux/blkdev.h> + + MODULE_LICENSE("CDDL"); + ],[ + struct request_queue *q = NULL; + (void) blk_queue_flush(q, REQ_FLUSH); + ],[ + AC_MSG_RESULT(no) + ],[ + AC_MSG_RESULT(yes) + AC_DEFINE(HAVE_BLK_QUEUE_FLUSH_GPL_ONLY, 1, + [blk_queue_flush() is GPL-only]) + ]) + EXTRA_KCFLAGS="$tmp_flags" +]) |