sanitize xattr handler prototypes

Add a flags argument to struct xattr_handler and pass it to all xattr
handler methods.  This allows using the same methods for multiple
handlers, e.g. for the ACL methods which perform exactly the same action
for the access and default ACLs, just using a different underlying
attribute.  With a little more groundwork it'll also allow sharing the
methods for the regular user/trusted/secure handlers in extN, ocfs2 and
jffs2 like it's already done for xfs in this patch.

Also change the inode argument to the handlers to a dentry to allow
using the handlers mechnism for filesystems that require it later,
e.g. cifs.

[with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ext4/xattr_security.c

@@ -12,8 +12,8 @@
 #include "xattr.h"
 
 static size_t
-ext4_xattr_security_list(struct inode *inode, char *list, size_t list_size,
-			 const char *name, size_t name_len)
+ext4_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
+		const char *name, size_t name_len, int type)
 {
 	const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
 	const size_t total_len = prefix_len + name_len + 1;
@@ -28,23 +28,23 @@ ext4_xattr_security_list(struct inode *inode, char *list, size_t list_size,
 }
 
 static int
-ext4_xattr_security_get(struct inode *inode, const char *name,
-		       void *buffer, size_t size)
+ext4_xattr_security_get(struct dentry *dentry, const char *name,
+		       void *buffer, size_t size, int type)
 {
 	if (strcmp(name, "") == 0)
 		return -EINVAL;
-	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_SECURITY, name,
-			      buffer, size);
+	return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
+			      name, buffer, size);
 }
 
 static int
-ext4_xattr_security_set(struct inode *inode, const char *name,
-		       const void *value, size_t size, int flags)
+ext4_xattr_security_set(struct dentry *dentry, const char *name,
+		const void *value, size_t size, int flags, int type)
 {
 	if (strcmp(name, "") == 0)
 		return -EINVAL;
-	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_SECURITY, name,
-			      value, size, flags);
+	return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
+			      name, value, size, flags);
 }
 
 int