[PATCH] move xattr permission checks into the VFS

)

From: Christoph Hellwig <hch@lst.de>

The xattr code has rather complex permission checks because the rules are very
different for different attribute namespaces.  This patch moves as much as we
can into the generic code.  Currently all the major disk based filesystems
duplicate these checks, while many minor filesystems or network filesystems
lack some or all of them.

To do this we need defines for the extended attribute names in common code, I
moved them up from JFS which had the nicest defintions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 366f0ab4219..cda8a96e2fa 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -13,7 +13,22 @@
 #define XATTR_CREATE	0x1	/* set value, fail if attr already exists */
 #define XATTR_REPLACE	0x2	/* set value, fail if attr does not exist */
 
+/* Namespaces */
+#define XATTR_OS2_PREFIX "os2."
+#define XATTR_OS2_PREFIX_LEN (sizeof (XATTR_OS2_PREFIX) - 1)
+
 #define XATTR_SECURITY_PREFIX	"security."
+#define XATTR_SECURITY_PREFIX_LEN (sizeof (XATTR_SECURITY_PREFIX) - 1)
+
+#define XATTR_SYSTEM_PREFIX "system."
+#define XATTR_SYSTEM_PREFIX_LEN (sizeof (XATTR_SYSTEM_PREFIX) - 1)
+
+#define XATTR_TRUSTED_PREFIX "trusted."
+#define XATTR_TRUSTED_PREFIX_LEN (sizeof (XATTR_TRUSTED_PREFIX) - 1)
+
+#define XATTR_USER_PREFIX "user."
+#define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1)
+
 
 struct xattr_handler {
 	char *prefix;