Merge branch 'sysctl-less-storage'

Eric Dumazet says:

====================
net: use less storage for most sysctl

This patch series adds a new sysctl type, to allow using u8 instead of
"int" or "long int" types.

Then we convert mosts sysctls found in struct netns_ipv4
to shrink it by three cache lines.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

fs/proc/proc_sysctl.c

@@ -1108,6 +1108,11 @@ static int sysctl_check_table_array(const char *path, struct ctl_table *table)
 			err |= sysctl_err(path, table, "array not allowed");
 	}
 
+	if (table->proc_handler == proc_dou8vec_minmax) {
+		if (table->maxlen != sizeof(u8))
+			err |= sysctl_err(path, table, "array not allowed");
+	}
+
 	return err;
 }
 
@@ -1123,6 +1128,7 @@ static int sysctl_check_table(const char *path, struct ctl_table *table)
 		    (table->proc_handler == proc_douintvec) ||
 		    (table->proc_handler == proc_douintvec_minmax) ||
 		    (table->proc_handler == proc_dointvec_minmax) ||
+		    (table->proc_handler == proc_dou8vec_minmax) ||
 		    (table->proc_handler == proc_dointvec_jiffies) ||
 		    (table->proc_handler == proc_dointvec_userhz_jiffies) ||
 		    (table->proc_handler == proc_dointvec_ms_jiffies) ||

include/linux/sysctl.h

@@ -53,6 +53,8 @@ int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *);
 int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
 int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer,
 		size_t *lenp, loff_t *ppos);
+int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer,
+			size_t *lenp, loff_t *ppos);
 int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *);
 int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *,
 		loff_t *);

include/net/netns/ipv4.h

@@ -83,41 +83,41 @@ struct netns_ipv4 {
 	struct xt_table		*nat_table;
 #endif
 
-	int sysctl_icmp_echo_ignore_all;
-	int sysctl_icmp_echo_ignore_broadcasts;
-	int sysctl_icmp_ignore_bogus_error_responses;
+	u8 sysctl_icmp_echo_ignore_all;
+	u8 sysctl_icmp_echo_ignore_broadcasts;
+	u8 sysctl_icmp_ignore_bogus_error_responses;
+	u8 sysctl_icmp_errors_use_inbound_ifaddr;
 	int sysctl_icmp_ratelimit;
 	int sysctl_icmp_ratemask;
-	int sysctl_icmp_errors_use_inbound_ifaddr;
 
 	struct local_ports ip_local_ports;
 
-	int sysctl_tcp_ecn;
-	int sysctl_tcp_ecn_fallback;
+	u8 sysctl_tcp_ecn;
+	u8 sysctl_tcp_ecn_fallback;
 
-	int sysctl_ip_default_ttl;
-	int sysctl_ip_no_pmtu_disc;
-	int sysctl_ip_fwd_use_pmtu;
-	int sysctl_ip_fwd_update_priority;
-	int sysctl_ip_nonlocal_bind;
-	int sysctl_ip_autobind_reuse;
+	u8 sysctl_ip_default_ttl;
+	u8 sysctl_ip_no_pmtu_disc;
+	u8 sysctl_ip_fwd_use_pmtu;
+	u8 sysctl_ip_fwd_update_priority;
+	u8 sysctl_ip_nonlocal_bind;
+	u8 sysctl_ip_autobind_reuse;
 	/* Shall we try to damage output packets if routing dev changes? */
-	int sysctl_ip_dynaddr;
-	int sysctl_ip_early_demux;
+	u8 sysctl_ip_dynaddr;
+	u8 sysctl_ip_early_demux;
 #ifdef CONFIG_NET_L3_MASTER_DEV
-	int sysctl_raw_l3mdev_accept;
+	u8 sysctl_raw_l3mdev_accept;
 #endif
-	int sysctl_tcp_early_demux;
-	int sysctl_udp_early_demux;
+	u8 sysctl_tcp_early_demux;
+	u8 sysctl_udp_early_demux;
 
-	int sysctl_nexthop_compat_mode;
+	u8 sysctl_nexthop_compat_mode;
 
-	int sysctl_fwmark_reflect;
-	int sysctl_tcp_fwmark_accept;
+	u8 sysctl_fwmark_reflect;
+	u8 sysctl_tcp_fwmark_accept;
 #ifdef CONFIG_NET_L3_MASTER_DEV
-	int sysctl_tcp_l3mdev_accept;
+	u8 sysctl_tcp_l3mdev_accept;
 #endif
-	int sysctl_tcp_mtu_probing;
+	u8 sysctl_tcp_mtu_probing;
 	int sysctl_tcp_mtu_probe_floor;
 	int sysctl_tcp_base_mss;
 	int sysctl_tcp_min_snd_mss;
@@ -125,46 +125,47 @@ struct netns_ipv4 {
 	u32 sysctl_tcp_probe_interval;
 
 	int sysctl_tcp_keepalive_time;
-	int sysctl_tcp_keepalive_probes;
 	int sysctl_tcp_keepalive_intvl;
+	u8 sysctl_tcp_keepalive_probes;
 
-	int sysctl_tcp_syn_retries;
-	int sysctl_tcp_synack_retries;
-	int sysctl_tcp_syncookies;
+	u8 sysctl_tcp_syn_retries;
+	u8 sysctl_tcp_synack_retries;
+	u8 sysctl_tcp_syncookies;
 	int sysctl_tcp_reordering;
-	int sysctl_tcp_retries1;
-	int sysctl_tcp_retries2;
-	int sysctl_tcp_orphan_retries;
+	u8 sysctl_tcp_retries1;
+	u8 sysctl_tcp_retries2;
+	u8 sysctl_tcp_orphan_retries;
+	u8 sysctl_tcp_tw_reuse;
 	int sysctl_tcp_fin_timeout;
 	unsigned int sysctl_tcp_notsent_lowat;
-	int sysctl_tcp_tw_reuse;
-	int sysctl_tcp_sack;
-	int sysctl_tcp_window_scaling;
-	int sysctl_tcp_timestamps;
-	int sysctl_tcp_early_retrans;
-	int sysctl_tcp_recovery;
-	int sysctl_tcp_thin_linear_timeouts;
-	int sysctl_tcp_slow_start_after_idle;
-	int sysctl_tcp_retrans_collapse;
-	int sysctl_tcp_stdurg;
-	int sysctl_tcp_rfc1337;
-	int sysctl_tcp_abort_on_overflow;
-	int sysctl_tcp_fack;
+	u8 sysctl_tcp_sack;
+	u8 sysctl_tcp_window_scaling;
+	u8 sysctl_tcp_timestamps;
+	u8 sysctl_tcp_early_retrans;
+	u8 sysctl_tcp_recovery;
+	u8 sysctl_tcp_thin_linear_timeouts;
+	u8 sysctl_tcp_slow_start_after_idle;
+	u8 sysctl_tcp_retrans_collapse;
+	u8 sysctl_tcp_stdurg;
+	u8 sysctl_tcp_rfc1337;
+	u8 sysctl_tcp_abort_on_overflow;
+	u8 sysctl_tcp_fack; /* obsolete */
 	int sysctl_tcp_max_reordering;
-	int sysctl_tcp_dsack;
-	int sysctl_tcp_app_win;
 	int sysctl_tcp_adv_win_scale;
-	int sysctl_tcp_frto;
-	int sysctl_tcp_nometrics_save;
-	int sysctl_tcp_no_ssthresh_metrics_save;
-	int sysctl_tcp_moderate_rcvbuf;
-	int sysctl_tcp_tso_win_divisor;
-	int sysctl_tcp_workaround_signed_windows;
+	u8 sysctl_tcp_dsack;
+	u8 sysctl_tcp_app_win;
+	u8 sysctl_tcp_frto;
+	u8 sysctl_tcp_nometrics_save;
+	u8 sysctl_tcp_no_ssthresh_metrics_save;
+	u8 sysctl_tcp_moderate_rcvbuf;
+	u8 sysctl_tcp_tso_win_divisor;
+	u8 sysctl_tcp_workaround_signed_windows;
 	int sysctl_tcp_limit_output_bytes;
 	int sysctl_tcp_challenge_ack_limit;
-	int sysctl_tcp_min_tso_segs;
 	int sysctl_tcp_min_rtt_wlen;
-	int sysctl_tcp_autocorking;
+	u8 sysctl_tcp_min_tso_segs;
+	u8 sysctl_tcp_autocorking;
+	u8 sysctl_tcp_reflect_tos;
 	int sysctl_tcp_invalid_ratelimit;
 	int sysctl_tcp_pacing_ss_ratio;
 	int sysctl_tcp_pacing_ca_ratio;
@@ -182,7 +183,6 @@ struct netns_ipv4 {
 	unsigned int sysctl_tcp_fastopen_blackhole_timeout;
 	atomic_t tfo_active_disable_times;
 	unsigned long tfo_active_disable_stamp;
-	int sysctl_tcp_reflect_tos;
 
 	int sysctl_udp_wmem_min;
 	int sysctl_udp_rmem_min;

kernel/sysctl.c

@@ -1034,6 +1034,65 @@ int proc_douintvec_minmax(struct ctl_table *table, int write,
 				 do_proc_douintvec_minmax_conv, &param);
 }
 
+/**
+ * proc_dou8vec_minmax - read a vector of unsigned chars with min/max values
+ * @table: the sysctl table
+ * @write: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ *
+ * Reads/writes up to table->maxlen/sizeof(u8) unsigned chars
+ * values from/to the user buffer, treated as an ASCII string. Negative
+ * strings are not allowed.
+ *
+ * This routine will ensure the values are within the range specified by
+ * table->extra1 (min) and table->extra2 (max).
+ *
+ * Returns 0 on success or an error on write when the range check fails.
+ */
+int proc_dou8vec_minmax(struct ctl_table *table, int write,
+			void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct ctl_table tmp;
+	unsigned int min = 0, max = 255U, val;
+	u8 *data = table->data;
+	struct do_proc_douintvec_minmax_conv_param param = {
+		.min = &min,
+		.max = &max,
+	};
+	int res;
+
+	/* Do not support arrays yet. */
+	if (table->maxlen != sizeof(u8))
+		return -EINVAL;
+
+	if (table->extra1) {
+		min = *(unsigned int *) table->extra1;
+		if (min > 255U)
+			return -EINVAL;
+	}
+	if (table->extra2) {
+		max = *(unsigned int *) table->extra2;
+		if (max > 255U)
+			return -EINVAL;
+	}
+
+	tmp = *table;
+
+	tmp.maxlen = sizeof(val);
+	tmp.data = &val;
+	val = *data;
+	res = do_proc_douintvec(&tmp, write, buffer, lenp, ppos,
+				do_proc_douintvec_minmax_conv, &param);
+	if (res)
+		return res;
+	if (write)
+		*data = val;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);
+
 static int do_proc_dopipe_max_size_conv(unsigned long *lvalp,
 					unsigned int *valp,
 					int write, void *data)
@@ -1582,6 +1641,12 @@ int proc_douintvec_minmax(struct ctl_table *table, int write,
 	return -ENOSYS;
 }
 
+int proc_dou8vec_minmax(struct ctl_table *table, int write,
+			void *buffer, size_t *lenp, loff_t *ppos)
+{
+	return -ENOSYS;
+}
+
 int proc_dointvec_jiffies(struct ctl_table *table, int write,
 		    void *buffer, size_t *lenp, loff_t *ppos)
 {