Simplify BDI integration

[zfs.git] / include / linux / vfs_compat.h

diff --git a/include/linux/vfs_compat.h b/include/linux/vfs_compat.h
index cbbf21e..825a7fd 100644 (file)
--- a/include/linux/vfs_compat.h
+++ b/include/linux/vfs_compat.h
@@ -62,23 +62,36 @@ truncate_setsize(struct inode *ip, loff_t new)
 }
 #endif /* HAVE_TRUNCATE_SETSIZE */
 
+#if defined(HAVE_BDI) && !defined(HAVE_BDI_SETUP_AND_REGISTER)
 /*
- * 2.6.32 API change,
- * Added backing_device_info (bdi) per super block interfaces.  When
- * available a bdi must be configured when using a non-device backed
- * filesystem for proper writeback.  It's safe to leave this code
- * dormant for kernels which only support pdflush and not bdi.
+ * 2.6.34 API change,
+ * Add bdi_setup_and_register() function if not yet provided by kernel.
+ * It is used to quickly initialize and register a BDI for the filesystem.
  */
-#ifdef HAVE_BDI
-#define        bdi_get_sb(sb)                          (sb->s_bdi)
-#define        bdi_put_sb(sb, bdi)                     (sb->s_bdi = bdi)
-#else
-#define        bdi_init(bdi)                           (0)
-#define        bdi_destroy(bdi)                        (0)
-#define        bdi_register(bdi, parent, fmt, args)    (0)
-#define        bdi_unregister(bdi)                     (0)
-#define        bdi_get_sb(sb)                          (0)
-#define        bdi_put_sb(sb, bdi)                     (0)
-#endif /* HAVE_BDI */
+extern atomic_long_t zfs_bdi_seq;
+
+static inline int
+bdi_setup_and_register(struct backing_dev_info *bdi,char *name,unsigned int cap)
+{
+       char tmp[32];
+       int error;
+
+       bdi->name = name;
+       bdi->capabilities = cap;
+       error = bdi_init(bdi);
+       if (error)
+               return (error);
+
+       sprintf(tmp, "%.28s%s", name, "-%d");
+       error = bdi_register(bdi, NULL, tmp,
+           atomic_long_inc_return(&zfs_bdi_seq));
+       if (error) {
+               bdi_destroy(bdi);
+               return (error);
+       }
+
+       return (error);
+}
+#endif /* HAVE_BDI && !HAVE_BDI_SETUP_AND_REGISTER */
 
 #endif /* _ZFS_VFS_H */