[PATCH] fsstack: Introduce fsstack_copy_{attr,inode}_*

Introduce several fsstack_copy_* functions which allow stackable filesystems
(such as eCryptfs and Unionfs) to easily copy over (currently only) inode
attributes.  This prevents code duplication and allows for code reuse.

[akpm@osdl.org: Remove unneeded wrapper]
[bunk@stusta.de: fs/stack.c should #include <linux/fs_stack.h>]
Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Josef "Jeff" Sipek 2006-12-08 02:36:31 -08:00 committed by Linus Torvalds
parent 17b3cff079
commit 42cf11939b
3 changed files with 73 additions and 1 deletions

View file

@ -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

40
fs/stack.c Normal file
View file

@ -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);

31
include/linux/fs_stack.h Normal file
View file

@ -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 */