Linux 4.4 compat: make_request_fn returns blk_qc_t

As part of block polling support in Linux 4.4, make_request_fn should
return a cookie value of type blk_qc_t. For now, we make zvol_request
always return BLK_QC_T_NONE until we assess whether and how we want
to support block polling.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4021

diff --git a/config/kernel-mk-request-fn.m4 b/config/kernel-mk-request-fn.m4
index 88ee2ebb3d007a0dde30fb92413154c6020b3b14..57eebe23de5beee1ea91c64446e210ccede75935 100644 (file)
--- a/config/kernel-mk-request-fn.m4
+++ b/config/kernel-mk-request-fn.m4
@@ -2,6 +2,9 @@ dnl #
 dnl # Linux 3.2 API Change
 dnl # make_request_fn returns void instead of int.
 dnl #
+dnl # Linux 4.4 API Change
+dnl # make_request_fn returns blk_qc_t.
+dnl #
 AC_DEFUN([ZFS_AC_KERNEL_MAKE_REQUEST_FN], [
        AC_MSG_CHECKING([whether make_request_fn() returns int])
        ZFS_LINUX_TRY_COMPILE([
@@ -36,8 +39,27 @@ AC_DEFUN([ZFS_AC_KERNEL_MAKE_REQUEST_FN], [
                        AC_DEFINE(MAKE_REQUEST_FN_RET, void,
                            [make_request_fn() returns void])
                ],[
-                       AC_MSG_ERROR(no - Please file a bug report at
-                           https://github.com/zfsonlinux/zfs/issues/new)
+                       AC_MSG_RESULT(no)
+                       AC_MSG_CHECKING([whether make_request_fn() returns blk_qc_t])
+                       ZFS_LINUX_TRY_COMPILE([
+                               #include <linux/blkdev.h>
+
+                               blk_qc_t make_request(struct request_queue *q, struct bio *bio)
+                               {
+                                       return (BLK_QC_T_NONE);
+                               }
+                       ],[
+                               blk_queue_make_request(NULL, &make_request);
+                       ],[
+                               AC_MSG_RESULT(yes)
+                               AC_DEFINE(MAKE_REQUEST_FN_RET, blk_qc_t,
+                                   [make_request_fn() returns blk_qc_t])
+                               AC_DEFINE(HAVE_MAKE_REQUEST_FN_RET_QC, 1,
+                                   [Noting that make_request_fn() returns blk_qc_t])
+                       ],[
+                               AC_MSG_ERROR(no - Please file a bug report at
+                                   https://github.com/zfsonlinux/zfs/issues/new)
+                       ])
                ])
        ])
 ])

diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
index cdaa838d23e49b782e709c7fdf563a9d562e35a8..574d3c306bc9964f24fa13ed1bf31f925c3f4371 100644 (file)
--- a/module/zfs/zvol.c
+++ b/module/zfs/zvol.c
@@ -755,6 +755,8 @@ out1:
        spl_fstrans_unmark(cookie);
 #ifdef HAVE_MAKE_REQUEST_FN_RET_INT
        return (0);
+#elif defined(HAVE_MAKE_REQUEST_FN_RET_QC)
+       return (BLK_QC_T_NONE);
 #endif
 }