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/reiserfs/xattr.c

@@ -48,6 +48,7 @@
 #include <net/checksum.h>
 #include <linux/stat.h>
 #include <linux/quotaops.h>
+#include <linux/security.h>
 
 #define PRIVROOT_NAME ".reiserfs_priv"
 #define XAROOT_NAME   "xattrs"
@@ -726,15 +727,14 @@ ssize_t
 reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
 		  size_t size)
 {
-	struct inode *inode = dentry->d_inode;
 	struct xattr_handler *handler;
 
-	handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
+	handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
 
-	if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
+	if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
 		return -EOPNOTSUPP;
 
-	return handler->get(inode, name, buffer, size);
+	return handler->get(dentry, name, buffer, size, handler->flags);
 }
 
 /*
@@ -746,15 +746,14 @@ int
 reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 		  size_t size, int flags)
 {
-	struct inode *inode = dentry->d_inode;
 	struct xattr_handler *handler;
 
-	handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
+	handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
 
-	if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
+	if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
 		return -EOPNOTSUPP;
 
-	return handler->set(inode, name, value, size, flags);
+	return handler->set(dentry, name, value, size, flags, handler->flags);
 }
 
 /*
@@ -764,21 +763,20 @@ reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
  */
 int reiserfs_removexattr(struct dentry *dentry, const char *name)
 {
-	struct inode *inode = dentry->d_inode;
 	struct xattr_handler *handler;
-	handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
+	handler = find_xattr_handler_prefix(dentry->d_sb->s_xattr, name);
 
-	if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
+	if (!handler || get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
 		return -EOPNOTSUPP;
 
-	return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
+	return handler->set(dentry, name, NULL, 0, XATTR_REPLACE, handler->flags);
 }
 
 struct listxattr_buf {
 	size_t size;
 	size_t pos;
 	char *buf;
-	struct inode *inode;
+	struct dentry *dentry;
 };
 
 static int listxattr_filler(void *buf, const char *name, int namelen,
@@ -789,17 +787,19 @@ static int listxattr_filler(void *buf, const char *name, int namelen,
 	if (name[0] != '.' ||
 	    (namelen != 1 && (name[1] != '.' || namelen != 2))) {
 		struct xattr_handler *handler;
-		handler = find_xattr_handler_prefix(b->inode->i_sb->s_xattr,
+		handler = find_xattr_handler_prefix(b->dentry->d_sb->s_xattr,
 						    name);
 		if (!handler)	/* Unsupported xattr name */
 			return 0;
 		if (b->buf) {
-			size = handler->list(b->inode, b->buf + b->pos,
-					 b->size, name, namelen);
+			size = handler->list(b->dentry, b->buf + b->pos,
+					 b->size, name, namelen,
+					 handler->flags);
 			if (size > b->size)
 				return -ERANGE;
 		} else {
-			size = handler->list(b->inode, NULL, 0, name, namelen);
+			size = handler->list(b->dentry, NULL, 0, name,
+					     namelen, handler->flags);
 		}
 
 		b->pos += size;
@@ -820,7 +820,7 @@ ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
 	int err = 0;
 	loff_t pos = 0;
 	struct listxattr_buf buf = {
-		.inode = dentry->d_inode,
+		.dentry = dentry,
 		.buf = buffer,
 		.size = buffer ? size : 0,
 	};