Don't send quota messages repeatedly when hardlimit reached

We should send quota message to netlink only once when hardlimit is
reached.  Otherwise user could easily make the system busy by trying to
exceed the hardlimit (and also the messages could be anoying if you cannot
stop writing just now).
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/dquot.c

@@ -827,6 +827,18 @@ static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
 	clear_bit(DQ_BLKS_B, &dquot->dq_flags);
 }
 
+static int warning_issued(struct dquot *dquot, const int warntype)
+{
+	int flag = (warntype == QUOTA_NL_BHARDWARN ||
+		warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
+		((warntype == QUOTA_NL_IHARDWARN ||
+		warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
+
+	if (!flag)
+		return 0;
+	return test_and_set_bit(flag, &dquot->dq_flags);
+}
+
 #ifdef CONFIG_PRINT_QUOTA_WARNING
 static int flag_print_warnings = 1;
 
@@ -845,16 +857,12 @@ static inline int need_print_warning(struct dquot *dquot)
 }
 
 /* Print warning to user which exceeded quota */
-static void print_warning(struct dquot *dquot, const char warntype)
+static void print_warning(struct dquot *dquot, const int warntype)
 {
 	char *msg = NULL;
 	struct tty_struct *tty;
-	int flag = (warntype == QUOTA_NL_BHARDWARN ||
-		warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
-		((warntype == QUOTA_NL_IHARDWARN ||
-		warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
 
-	if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags)))
+	if (!need_print_warning(dquot))
 		return;
 
 	mutex_lock(&tty_mutex);
@@ -969,7 +977,8 @@ static inline void flush_warnings(struct dquot * const *dquots, char *warntype)
 	int i;
 
 	for (i = 0; i < MAXQUOTAS; i++)
-		if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN) {
+		if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN &&
+		    !warning_issued(dquots[i], warntype[i])) {
 #ifdef CONFIG_PRINT_QUOTA_WARNING
 			print_warning(dquots[i], warntype[i]);
 #endif