Linux 4.11 compat: super_setup_bdi_name()

All filesystems were converted to dynamically allocated BDIs. The destruction of backing_dev_info structures is handled as part of super block destruction. Signed-off-by: Brian Behlendorf <[email protected]>
openzfs · May 1, 2017 · d053c16 · d053c16
1 parent 153b228
commit d053c16
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Showing 5 changed files with 95 additions and 48 deletions.
diff --git a/config/kernel-bdi-setup-and-register.m4 b/config/kernel-bdi-setup-and-register.m4
diff --git a/config/kernel-bdi.m4 b/config/kernel-bdi.m4
@@ -0,0 +1,56 @@
+dnl #
+dnl # 2.6.32 - 2.6.33, bdi_setup_and_register() is not exported.
+dnl # 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
+dnl # 4.0 - 4.10, bdi_setup_and_register() takes 2 arguments.
+dnl # 4.11 - x.y, super_setup_bdi_name() new interface.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_BDI], [
+	AC_MSG_CHECKING([whether super_setup_bdi_name() exists])
+	ZFS_LINUX_TRY_COMPILE_SYMBOL([
+		#include <linux/fs.h>
+		struct super_block sb;
+	], [
+		char *name = "bdi";
+		int error __attribute__((unused)) =
+		    super_setup_bdi_name(&sb, name);
+	], [super_setup_bdi_name], [fs/super.c], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_SUPER_SETUP_BDI_NAME, 1,
+                    [super_setup_bdi_name() exits])
+	], [
+		AC_MSG_RESULT(no)
+		AC_MSG_CHECKING(
+		    [whether bdi_setup_and_register() wants 2 args])
+		ZFS_LINUX_TRY_COMPILE_SYMBOL([
+			#include <linux/backing-dev.h>
+			struct backing_dev_info bdi;
+		], [
+			char *name = "bdi";
+			int error __attribute__((unused)) =
+			    bdi_setup_and_register(&bdi, name);
+		], [bdi_setup_and_register], [mm/backing-dev.c], [
+			AC_MSG_RESULT(yes)
+			AC_DEFINE(HAVE_2ARGS_BDI_SETUP_AND_REGISTER, 1,
+			    [bdi_setup_and_register() wants 2 args])
+		], [
+			AC_MSG_RESULT(no)
+			AC_MSG_CHECKING(
+			    [whether bdi_setup_and_register() wants 3 args])
+			ZFS_LINUX_TRY_COMPILE_SYMBOL([
+				#include <linux/backing-dev.h>
+				struct backing_dev_info bdi;
+			], [
+				char *name = "bdi";
+				unsigned int cap = BDI_CAP_MAP_COPY;
+				int error __attribute__((unused)) =
+				    bdi_setup_and_register(&bdi, name, cap);
+			], [bdi_setup_and_register], [mm/backing-dev.c], [
+				AC_MSG_RESULT(yes)
+				AC_DEFINE(HAVE_3ARGS_BDI_SETUP_AND_REGISTER, 1,
+				    [bdi_setup_and_register() wants 3 args])
+			], [
+				AC_MSG_RESULT(no)
+			])
+		])
+	])
+])
diff --git a/config/kernel.m4 b/config/kernel.m4
@@ -100,7 +100,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
 	ZFS_AC_KERNEL_SHRINK_CONTROL_HAS_NID
 	ZFS_AC_KERNEL_S_INSTANCES_LIST_HEAD
 	ZFS_AC_KERNEL_S_D_OP
-	ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER
+	ZFS_AC_KERNEL_BDI
 	ZFS_AC_KERNEL_SET_NLINK
 	ZFS_AC_KERNEL_ELEVATOR_CHANGE
 	ZFS_AC_KERNEL_5ARG_SGET

diff --git a/include/linux/vfs_compat.h b/include/linux/vfs_compat.h
@@ -70,29 +70,53 @@ truncate_setsize(struct inode *ip, loff_t new)
 /*
  * 2.6.32 - 2.6.33, bdi_setup_and_register() is not available.
  * 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
- * 4.0 - x.y, bdi_setup_and_register() takes 2 arguments.
+ * 4.0 - 4.10, bdi_setup_and_register() takes 2 arguments.
+ * 4.11 - x.y, super_setup_bdi_name() new interface.
  */
-#if defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER)
+#if defined(HAVE_SUPER_SETUP_BDI_NAME)
 static inline int
-zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
+zpl_bdi_setup(struct super_block *sb, struct backing_dev_info *bdi, char *name)
 {
+	return (super_setup_bdi_name(sb, name));
+}
+static inline void
+zpl_bdi_destroy(struct backing_dev_info *bdi)
+{
+}
+#elif defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER)
+static inline int
+zpl_bdi_setup(struct super_block *sb, struct backing_dev_info *bdi, char *name)
+{
+	sb->s_bdi = bdi;
 	return (bdi_setup_and_register(bdi, name));
 }
+static inline void
+zpl_bdi_destroy(struct backing_dev_info *bdi)
+{
+	bdi_destroy(bdi);
+}
 #elif defined(HAVE_3ARGS_BDI_SETUP_AND_REGISTER)
 static inline int
-zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
+zpl_bdi_setup(struct super_block *sb, struct backing_dev_info *bdi, char *name)
 {
+	sb->s_bdi = bdi;
 	return (bdi_setup_and_register(bdi, name, BDI_CAP_MAP_COPY));
 }
+static inline void
+zpl_bdi_destroy(struct backing_dev_info *bdi)
+{
+	bdi_destroy(bdi);
+}
 #else
 extern atomic_long_t zfs_bdi_seq;
 
 static inline int
-zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
+zpl_bdi_setup(struct super_block *sb, struct backing_dev_info *bdi, char *name)
 {
 	char tmp[32];
 	int error;
 
+	sb->s_bdi = bdi;
 	bdi->name = name;
 	bdi->capabilities = BDI_CAP_MAP_COPY;
 
@@ -110,6 +134,11 @@ zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
 
 	return (error);
 }
+static inline void
+zpl_bdi_destroy(struct backing_dev_info *bdi)
+{
+	bdi_destroy(bdi);
+}
 #endif
 
 /*

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
@@ -1568,7 +1568,8 @@ zfsvfs_teardown(zfsvfs_t *zfsvfs, boolean_t unmounting)
 	return (0);
 }
 
-#if !defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER) && \
+#if !defined(HAVE_SUPER_SETUP_BDI_NAME) && \
+	!defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER) && \
 	!defined(HAVE_3ARGS_BDI_SETUP_AND_REGISTER)
 atomic_long_t zfs_bdi_seq = ATOMIC_LONG_INIT(0);
 #endif
@@ -1606,9 +1607,8 @@ zfs_domount(struct super_block *sb, zfs_mnt_t *zm, int silent)
 	sb->s_blocksize = recordsize;
 	sb->s_blocksize_bits = ilog2(recordsize);
 	zfsvfs->z_bdi.ra_pages = 0;
-	sb->s_bdi = &zfsvfs->z_bdi;
 
-	error = -zpl_bdi_setup_and_register(&zfsvfs->z_bdi, "zfs");
+	error = -zpl_bdi_setup(sb, &zfsvfs->z_bdi, "zfs");
 	if (error)
 		goto out;
 
@@ -1732,7 +1732,7 @@ zfs_umount(struct super_block *sb)
 	arc_remove_prune_callback(zfsvfs->z_arc_prune);
 	VERIFY(zfsvfs_teardown(zfsvfs, B_TRUE) == 0);
 	os = zfsvfs->z_os;
-	bdi_destroy(sb->s_bdi);
+	zpl_bdi_destroy(sb->s_bdi);
 
 	/*
 	 * z_os will be NULL if there was an error in