[RFC] [PATCH 4/8] inode-diet: Move i_cdev into a union

[Theodore Tso <tytso@thunk.org>]

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Move the i_cdev pointer in struct inode into a union.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>


Index: linux-2.6.17/include/linux/fs.h
===================================================================
--- linux-2.6.17.orig/include/linux/fs.h	2006-06-18 19:46:10.000000000 -0400
+++ linux-2.6.17/include/linux/fs.h	2006-06-18 19:50:56.000000000 -0400
@@ -512,8 +512,8 @@
 	union {
 		struct pipe_inode_info	*i_pipe;
 		struct block_device	*i_bdev;
+		struct cdev		*i_cdev;
 	};
-	struct cdev		*i_cdev;
 	int			i_cindex;
 
 	__u32			i_generation;
Index: linux-2.6.17/fs/file_table.c
===================================================================
--- linux-2.6.17.orig/fs/file_table.c	2006-06-18 19:37:14.000000000 -0400
+++ linux-2.6.17/fs/file_table.c	2006-06-18 19:50:56.000000000 -0400
@@ -170,7 +170,7 @@
 	if (file->f_op && file->f_op->release)
 		file->f_op->release(inode, file);
 	security_file_free(file);
-	if (unlikely(inode->i_cdev != NULL))
+	if (unlikely(S_ISCHR(inode->i_mode) && (inode->i_cdev != NULL)))
 		cdev_put(inode->i_cdev);
 	fops_put(file->f_op);
 	if (file->f_mode & FMODE_WRITE)
Index: linux-2.6.17/fs/inode.c
===================================================================
--- linux-2.6.17.orig/fs/inode.c	2006-06-18 19:46:10.000000000 -0400
+++ linux-2.6.17/fs/inode.c	2006-06-18 19:50:56.000000000 -0400
@@ -257,7 +257,7 @@
 		inode->i_sb->s_op->clear_inode(inode);
 	if (S_ISBLK(inode->i_mode) && inode->i_bdev)
 		bd_forget(inode);
-	if (inode->i_cdev)
+	if (S_ISCHR(inode->i_mode) && inode->i_cdev)
 		cd_forget(inode);
 	inode->i_state = I_CLEAR;
 }

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