quota: send messages via netlink

Implement sending of quota messages via netlink interface.  The advantage
is that in userspace we can better decide what to do with the message - for
example display a dialogue in your X session or just write the message to
the console.  As a bonus, we can get rid of problems with console locking
deep inside filesystem code once we remove the old printing mechanism.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/quota.h b/include/linux/quota.h
index 6243982..6e0393a 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -128,6 +128,37 @@
 	__u32 dqi_valid;
 };
 
+/*
+ * Definitions for quota netlink interface
+ */
+#define QUOTA_NL_NOWARN 0
+#define QUOTA_NL_IHARDWARN 1		/* Inode hardlimit reached */
+#define QUOTA_NL_ISOFTLONGWARN 2 	/* Inode grace time expired */
+#define QUOTA_NL_ISOFTWARN 3		/* Inode softlimit reached */
+#define QUOTA_NL_BHARDWARN 4		/* Block hardlimit reached */
+#define QUOTA_NL_BSOFTLONGWARN 5	/* Block grace time expired */
+#define QUOTA_NL_BSOFTWARN 6		/* Block softlimit reached */
+
+enum {
+	QUOTA_NL_C_UNSPEC,
+	QUOTA_NL_C_WARNING,
+	__QUOTA_NL_C_MAX,
+};
+#define QUOTA_NL_C_MAX (__QUOTA_NL_C_MAX - 1)
+
+enum {
+	QUOTA_NL_A_UNSPEC,
+	QUOTA_NL_A_QTYPE,
+	QUOTA_NL_A_EXCESS_ID,
+	QUOTA_NL_A_WARNING,
+	QUOTA_NL_A_DEV_MAJOR,
+	QUOTA_NL_A_DEV_MINOR,
+	QUOTA_NL_A_CAUSED_ID,
+	__QUOTA_NL_A_MAX,
+};
+#define QUOTA_NL_A_MAX (__QUOTA_NL_A_MAX - 1)
+
+
 #ifdef __KERNEL__
 #include <linux/spinlock.h>
 #include <linux/rwsem.h>