[PATCH] vfat dentry handling fix (3/11)

This fixes filename case handling in vfat_revalidate():

before:
	# mount -t vfat /dev/hda6 /mnt -o shortname=winnt
	# cd /mnt
	# cat File.Txt			# make negative dentry
	cat: File.Txt: No such file or directory
	# touch file.txt		# match negative dentry
	# ls
	File.Txt

after:
	# mount -t vfat /dev/hda6 /mnt -o shortname=winnt
	# cd /mnt
	# cat File.Txt			# make negative dentry
	cat: File.Txt: No such file or directory
	# touch file.txt		# match negative dentry
	# ls
	file.txt

fs/vfat/namei.c

@@ -23,6 +23,7 @@
 #include <linux/slab.h>
 #include <linux/smp_lock.h>
 #include <linux/buffer_head.h>
+#include <linux/namei.h>
 
 #define DEBUG_LEVEL 0
 #if (DEBUG_LEVEL >= 1)
@@ -70,14 +71,20 @@ static struct dentry_operations vfat_dentry_ops[4] = {
 
 static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
+	int ret = 1;
 	PRINTK1(("vfat_revalidate: %s\n", dentry->d_name.name));
 	spin_lock(&dcache_lock);
-	if (dentry->d_time == dentry->d_parent->d_inode->i_version) {
-		spin_unlock(&dcache_lock);
-		return 1;
-	}
+	if (nd && !(nd->flags & LOOKUP_CONTINUE) && (nd->flags & LOOKUP_CREATE))
+		/*
+		 * negative dentry is dropped, in order to make sure
+		 * to use the name which a user desires if this is
+		 * create path.
+		 */
+		ret = 0;
+	else if (dentry->d_time != dentry->d_parent->d_inode->i_version)
+		ret = 0;
 	spin_unlock(&dcache_lock);
-	return 0;
+	return ret;
 }
 
 static inline unsigned char