autoconf: AC_MSG_CHECKING consistency

Make the wording more consistent for the kernel AC_MSG_CHECKING
output (e.g. "checking whether ...".).  Additionally, group some
of the VFS interface checks with the others.  No functional change.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Attila Fülöp <attila@fueloep.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13529

config/kernel-bio.m4

@@ -464,7 +464,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BLK_CGROUP_HEADER], [
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_BLK_CGROUP_HEADER], [
-	AC_MSG_CHECKING([for existence of linux/blk-cgroup.h])
+	AC_MSG_CHECKING([whether linux/blk-cgroup.h exists])
 	ZFS_LINUX_TEST_RESULT([blk_cgroup_header],[
 		AC_MSG_RESULT(yes)
 		AC_DEFINE(HAVE_LINUX_BLK_CGROUP_HEADER, 1,
@@ -500,7 +500,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_BIO_ALLOC_4ARG], [
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_BIO_ALLOC_4ARG], [
-	AC_MSG_CHECKING([for 4-argument bio_alloc()])
+	AC_MSG_CHECKING([whether bio_alloc() wants 4 args])
 	ZFS_LINUX_TEST_RESULT([bio_alloc_4arg],[
 		AC_MSG_RESULT(yes)
 		AC_DEFINE([HAVE_BIO_ALLOC_4ARG], 1, [bio_alloc() takes 4 arguments])

config/kernel-pagemap-folio_wait_bit.m4

@@ -15,7 +15,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_PAGEMAP_FOLIO_WAIT_BIT], [
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_PAGEMAP_FOLIO_WAIT_BIT], [
-	AC_MSG_CHECKING([folio_wait_bit() exists])
+	AC_MSG_CHECKING([whether folio_wait_bit() exists])
 	ZFS_LINUX_TEST_RESULT([pagemap_has_folio_wait_bit], [
 		AC_MSG_RESULT([yes])
 		AC_DEFINE(HAVE_PAGEMAP_FOLIO_WAIT_BIT, 1,

config/kernel-readpages.m4

@@ -14,7 +14,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_VFS_READPAGES], [
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_VFS_READPAGES], [
-	AC_MSG_CHECKING([address_space_operations->readpages exists])
+	AC_MSG_CHECKING([whether aops->readpages exists])
 	ZFS_LINUX_TEST_RESULT([vfs_has_readpages], [
 		AC_MSG_RESULT([yes])
 		AC_DEFINE(HAVE_VFS_READPAGES, 1,

config/kernel-shrink.m4

@@ -84,7 +84,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_SHRINKER_CALLBACK], [
 AC_DEFUN([ZFS_AC_KERNEL_SHRINKER_CALLBACK],[
 	dnl #
 	dnl # 3.0 - 3.11 API change
-	dnl # ->shrink(struct shrinker *, struct shrink_control *sc)
+	dnl # cs->shrink(struct shrinker *, struct shrink_control *sc)
 	dnl #
 	AC_MSG_CHECKING([whether new 2-argument shrinker exists])
 	ZFS_LINUX_TEST_RESULT([shrinker_cb_shrink_control], [
@@ -96,14 +96,14 @@ AC_DEFUN([ZFS_AC_KERNEL_SHRINKER_CALLBACK],[
 
 		dnl #
 		dnl # 3.12 API change,
-		dnl # ->shrink() is logically split in to
+		dnl # cs->shrink() is logically split in to
-		dnl # ->count_objects() and ->scan_objects()
+		dnl # cs->count_objects() and cs->scan_objects()
 		dnl #
-		AC_MSG_CHECKING([whether ->count_objects callback exists])
+		AC_MSG_CHECKING([whether cs->count_objects callback exists])
 		ZFS_LINUX_TEST_RESULT([shrinker_cb_shrink_control_split], [
 			AC_MSG_RESULT(yes)
 			AC_DEFINE(HAVE_SPLIT_SHRINKER_CALLBACK, 1,
-			    [->count_objects exists])
+			    [cs->count_objects exists])
 		],[
 			ZFS_LINUX_TEST_ERROR([shrinker])
 		])

config/kernel-sysfs.m4

@@ -19,7 +19,7 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_SYSFS_DEFAULT_GROUPS], [
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_SYSFS_DEFAULT_GROUPS], [
-	AC_MSG_CHECKING([for struct kobj_type.default_groups])
+	AC_MSG_CHECKING([whether struct kobj_type.default_groups exists])
 	ZFS_LINUX_TEST_RESULT([sysfs_default_groups],[
 		AC_MSG_RESULT(yes)
 		AC_DEFINE([HAVE_SYSFS_DEFAULT_GROUPS], 1, [struct kobj_type has default_groups])

config/kernel-vfs-filemap_dirty_folio.m4

@@ -19,7 +19,7 @@ AC_DEFUN([ZFS_AC_KERNEL_VFS_FILEMAP_DIRTY_FOLIO], [
 	dnl # Linux 5.18 uses filemap_dirty_folio in lieu of
 	dnl # ___set_page_dirty_nobuffers
 	dnl #
-	AC_MSG_CHECKING([filemap_dirty_folio exists])
+	AC_MSG_CHECKING([whether filemap_dirty_folio exists])
 	ZFS_LINUX_TEST_RESULT([vfs_has_filemap_dirty_folio], [
 		AC_MSG_RESULT([yes])
 		AC_DEFINE(HAVE_VFS_FILEMAP_DIRTY_FOLIO, 1,

config/kernel-vfs-read_folio.m4

@@ -22,7 +22,7 @@ AC_DEFUN([ZFS_AC_KERNEL_VFS_READ_FOLIO], [
 	dnl #
 	dnl # Linux 5.19 uses read_folio in lieu of readpage
 	dnl #
-	AC_MSG_CHECKING([read_folio exists])
+	AC_MSG_CHECKING([whether read_folio exists])
 	ZFS_LINUX_TEST_RESULT([vfs_has_read_folio], [
 		AC_MSG_RESULT([yes])
 		AC_DEFINE(HAVE_VFS_READ_FOLIO, 1, [read_folio exists])

config/kernel-vfs-set_page_dirty.m4

@@ -23,7 +23,7 @@ AC_DEFUN([ZFS_AC_KERNEL_VFS_SET_PAGE_DIRTY_NOBUFFERS], [
 	dnl # Linux 5.14 change requires set_page_dirty() to be assigned
 	dnl # in address_space_operations()
 	dnl #
-	AC_MSG_CHECKING([__set_page_dirty_nobuffers exists])
+	AC_MSG_CHECKING([whether __set_page_dirty_nobuffers exists])
 	ZFS_LINUX_TEST_RESULT([vfs_has_set_page_dirty_nobuffers], [
 		AC_MSG_RESULT([yes])
 		AC_DEFINE(HAVE_VFS_SET_PAGE_DIRTY_NOBUFFERS, 1,

config/kernel.m4

@@ -106,6 +106,8 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
 	ZFS_AC_KERNEL_SRC_VFS_FSYNC_2ARGS
 	ZFS_AC_KERNEL_SRC_VFS_ITERATE
 	ZFS_AC_KERNEL_SRC_VFS_DIRECT_IO
+	ZFS_AC_KERNEL_SRC_VFS_READPAGES
+	ZFS_AC_KERNEL_SRC_VFS_SET_PAGE_DIRTY_NOBUFFERS
 	ZFS_AC_KERNEL_SRC_VFS_RW_ITERATE
 	ZFS_AC_KERNEL_SRC_VFS_GENERIC_WRITE_CHECKS
 	ZFS_AC_KERNEL_SRC_VFS_IOV_ITER
@@ -136,8 +138,6 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
 	ZFS_AC_KERNEL_SRC_SIGINFO
 	ZFS_AC_KERNEL_SRC_SYSFS
 	ZFS_AC_KERNEL_SRC_SET_SPECIAL_STATE
-	ZFS_AC_KERNEL_SRC_VFS_READPAGES
-	ZFS_AC_KERNEL_SRC_VFS_SET_PAGE_DIRTY_NOBUFFERS
 	ZFS_AC_KERNEL_SRC_STANDALONE_LINUX_STDARG
 	ZFS_AC_KERNEL_SRC_PAGEMAP_FOLIO_WAIT_BIT
 	ZFS_AC_KERNEL_SRC_ADD_DISK
@@ -223,6 +223,8 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
 	ZFS_AC_KERNEL_VFS_FSYNC_2ARGS
 	ZFS_AC_KERNEL_VFS_ITERATE
 	ZFS_AC_KERNEL_VFS_DIRECT_IO
+	ZFS_AC_KERNEL_VFS_READPAGES
+	ZFS_AC_KERNEL_VFS_SET_PAGE_DIRTY_NOBUFFERS
 	ZFS_AC_KERNEL_VFS_RW_ITERATE
 	ZFS_AC_KERNEL_VFS_GENERIC_WRITE_CHECKS
 	ZFS_AC_KERNEL_VFS_IOV_ITER
@@ -253,8 +255,6 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
 	ZFS_AC_KERNEL_SIGINFO
 	ZFS_AC_KERNEL_SYSFS
 	ZFS_AC_KERNEL_SET_SPECIAL_STATE
-	ZFS_AC_KERNEL_VFS_READPAGES
-	ZFS_AC_KERNEL_VFS_SET_PAGE_DIRTY_NOBUFFERS
 	ZFS_AC_KERNEL_STANDALONE_LINUX_STDARG
 	ZFS_AC_KERNEL_PAGEMAP_FOLIO_WAIT_BIT
 	ZFS_AC_KERNEL_ADD_DISK