btrfs: move the 32bit warn defines into messages.h

The code for these functions are in messages.c, move the defines and
prototypes to messages.h.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -695,19 +695,6 @@ int btrfs_sync_fs(struct super_block *sb, int wait);
 char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
 					  u64 subvol_objectid);
 
-#if BITS_PER_LONG == 32
-#define BTRFS_32BIT_MAX_FILE_SIZE (((u64)ULONG_MAX + 1) << PAGE_SHIFT)
-/*
- * The warning threshold is 5/8th of the MAX_LFS_FILESIZE that limits the logical
- * addresses of extents.
- *
- * For 4K page size it's about 10T, for 64K it's 160T.
- */
-#define BTRFS_32BIT_EARLY_WARN_THRESHOLD (BTRFS_32BIT_MAX_FILE_SIZE * 5 / 8)
-void btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info);
-void btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info);
-#endif
-
 /*
  * Get the correct offset inside the page of extent buffer.
  *

fs/btrfs/messages.h

@@ -229,4 +229,17 @@ do {									\
 	BUG();								\
 } while (0)
 
+#if BITS_PER_LONG == 32
+#define BTRFS_32BIT_MAX_FILE_SIZE (((u64)ULONG_MAX + 1) << PAGE_SHIFT)
+/*
+ * The warning threshold is 5/8th of the MAX_LFS_FILESIZE that limits the logical
+ * addresses of extents.
+ *
+ * For 4K page size it's about 10T, for 64K it's 160T.
+ */
+#define BTRFS_32BIT_EARLY_WARN_THRESHOLD (BTRFS_32BIT_MAX_FILE_SIZE * 5 / 8)
+void btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info);
+void btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info);
+#endif
+
 #endif