9p: xattr simplifications

Now that the xattr handler is passed to the xattr handler operations, we
can use the same get and set operations for the user, trusted, and security
xattr namespaces.  In those namespaces, we can access the full attribute
name by "reattaching" the name prefix the vfs has skipped for us.  Add a
xattr_full_name helper to make this obvious in the code.

For the "system.posix_acl_access" and "system.posix_acl_default"
attributes, handler->prefix is the full attribute name; the suffix is the
empty string.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: v9fs-developer@lists.sourceforge.net
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 11 insertions, 7 deletions

diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 91b0a68d38dc..89474b9d260c 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -21,15 +21,19 @@ struct dentry;
 
 struct xattr_handler {
 	const char *prefix;
-	int flags;	/* fs private flags passed back to the handlers */
-	size_t (*list)(struct dentry *dentry, char *list, size_t list_size,
-		       const char *name, size_t name_len, int handler_flags);
-	int (*get)(struct dentry *dentry, const char *name, void *buffer,
-		   size_t size, int handler_flags);
-	int (*set)(struct dentry *dentry, const char *name, const void *buffer,
-		   size_t size, int flags, int handler_flags);
+	int flags;      /* fs private flags */
+	size_t (*list)(const struct xattr_handler *, struct dentry *dentry,
+		       char *list, size_t list_size, const char *name,
+		       size_t name_len);
+	int (*get)(const struct xattr_handler *, struct dentry *dentry,
+		   const char *name, void *buffer, size_t size);
+	int (*set)(const struct xattr_handler *, struct dentry *dentry,
+		   const char *name, const void *buffer, size_t size,
+		   int flags);
 };
 
+const char *xattr_full_name(const struct xattr_handler *, const char *);
+
 struct xattr {
 	const char *name;
 	void *value;