From 8519d9091ae15a5aadd8a62cfdd848f6962044e7 Mon Sep 17 00:00:00 2001
From: "Josef \"Jeff\" Sipek" <jsipek@cs.sunysb.edu>
Date: Fri, 8 Dec 2006 02:36:31 -0800
Subject: [PATCH] --- yaml --- r: 43519 b: refs/heads/master c:
 42cf11939becc717bd125d121a1a23415106a099 h: refs/heads/master i:   43517:
 a8acf015617a426d325ae74f91cc67b04816e012   43515:
 5f3bc220b3cec4ce70fc5c44ee6b15cdb11e3446   43511:
 6f464eadcf607581e960ad2b4d5837c9c4269d36   43503:
 103c8f04c0902bea3608a7eda9ec02892649dc07   43487:
 449134bb85dfd763f8074fc183e122edb340b011   43455:
 29dc026bca6c1a1eae2b4f3a620ebaf91ad361e5   43391:
 c5b2420ca7d1efe65d9674b9a81af94b1d244218   43263:
 1dbcf7488b7b5a18170d2d55543fe63b24a0ab2f   43007:
 23e9d19e58e5378fbad97b428c0f4698af9d42e6 v: v3

---
 [refs]                         |  2 +-
 trunk/fs/Makefile              |  3 ++-
 trunk/fs/stack.c               | 40 ++++++++++++++++++++++++++++++++++
 trunk/include/linux/fs_stack.h | 31 ++++++++++++++++++++++++++
 4 files changed, 74 insertions(+), 2 deletions(-)
 create mode 100644 trunk/fs/stack.c
 create mode 100644 trunk/include/linux/fs_stack.h

diff --git a/[refs] b/[refs]
index 927b38a4ea73..046fde875684 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 17b3cff079721bbc45e9d6de2fa3edb73561e27d
+refs/heads/master: 42cf11939becc717bd125d121a1a23415106a099
diff --git a/trunk/fs/Makefile b/trunk/fs/Makefile
index 9a5ce9323bfd..b9ffa63f77fc 100644
--- a/trunk/fs/Makefile
+++ b/trunk/fs/Makefile
@@ -10,7 +10,8 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		ioctl.o readdir.o select.o fifo.o locks.o dcache.o inode.o \
 		attr.o bad_inode.o file.o filesystems.o namespace.o aio.o \
 		seq_file.o xattr.o libfs.o fs-writeback.o \
-		pnode.o drop_caches.o splice.o sync.o utimes.o
+		pnode.o drop_caches.o splice.o sync.o utimes.o \
+		stack.o
 
 ifeq ($(CONFIG_BLOCK),y)
 obj-y +=	buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
diff --git a/trunk/fs/stack.c b/trunk/fs/stack.c
new file mode 100644
index 000000000000..5ddbc34535f9
--- /dev/null
+++ b/trunk/fs/stack.c
@@ -0,0 +1,40 @@
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/fs_stack.h>
+
+/* does _NOT_ require i_mutex to be held.
+ *
+ * This function cannot be inlined since i_size_{read,write} is rather
+ * heavy-weight on 32-bit systems
+ */
+void fsstack_copy_inode_size(struct inode *dst, const struct inode *src)
+{
+	i_size_write(dst, i_size_read((struct inode *)src));
+	dst->i_blocks = src->i_blocks;
+}
+EXPORT_SYMBOL_GPL(fsstack_copy_inode_size);
+
+/* copy all attributes; get_nlinks is optional way to override the i_nlink
+ * copying
+ */
+void fsstack_copy_attr_all(struct inode *dest, const struct inode *src,
+				int (*get_nlinks)(struct inode *))
+{
+	if (!get_nlinks)
+		dest->i_nlink = src->i_nlink;
+	else
+		dest->i_nlink = (*get_nlinks)(dest);
+
+	dest->i_mode = src->i_mode;
+	dest->i_uid = src->i_uid;
+	dest->i_gid = src->i_gid;
+	dest->i_rdev = src->i_rdev;
+	dest->i_atime = src->i_atime;
+	dest->i_mtime = src->i_mtime;
+	dest->i_ctime = src->i_ctime;
+	dest->i_blkbits = src->i_blkbits;
+	dest->i_flags = src->i_flags;
+
+	fsstack_copy_inode_size(dest, src);
+}
+EXPORT_SYMBOL_GPL(fsstack_copy_attr_all);
diff --git a/trunk/include/linux/fs_stack.h b/trunk/include/linux/fs_stack.h
new file mode 100644
index 000000000000..bb516ceeefc9
--- /dev/null
+++ b/trunk/include/linux/fs_stack.h
@@ -0,0 +1,31 @@
+#ifndef _LINUX_FS_STACK_H
+#define _LINUX_FS_STACK_H
+
+/* This file defines generic functions used primarily by stackable
+ * filesystems; none of these functions require i_mutex to be held.
+ */
+
+#include <linux/fs.h>
+
+/* externs for fs/stack.c */
+extern void fsstack_copy_attr_all(struct inode *dest, const struct inode *src,
+				int (*get_nlinks)(struct inode *));
+
+extern void fsstack_copy_inode_size(struct inode *dst, const struct inode *src);
+
+/* inlines */
+static inline void fsstack_copy_attr_atime(struct inode *dest,
+					   const struct inode *src)
+{
+	dest->i_atime = src->i_atime;
+}
+
+static inline void fsstack_copy_attr_times(struct inode *dest,
+					   const struct inode *src)
+{
+	dest->i_atime = src->i_atime;
+	dest->i_mtime = src->i_mtime;
+	dest->i_ctime = src->i_ctime;
+}
+
+#endif /* _LINUX_FS_STACK_H */