[RFC PATCH 26/39] rds: preserve live reconnect limits with numeric bounds

[wen.yang@linux.dev]

From: Wen Yang <wen.yang@linux.dev>

Refresh reconnect bounds while preserving jiffies conversion.

Suggested-by: Joel Granados <joel.granados@kernel.org>
Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 net/rds/sysctl.c | 32 +++++++++++++++++++++++++-------
 net/rds/tcp.c    | 11 +++++------
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/net/rds/sysctl.c b/net/rds/sysctl.c
index 025f518a4349..b32213b8ad96 100644
--- a/net/rds/sysctl.c
+++ b/net/rds/sysctl.c
@@ -39,7 +39,6 @@
 static struct ctl_table_header *rds_sysctl_reg_table;
 
 static unsigned long rds_sysctl_reconnect_min = 1;
-static unsigned long rds_sysctl_reconnect_max = ~0UL;
 
 unsigned long rds_sysctl_reconnect_min_jiffies;
 unsigned long rds_sysctl_reconnect_max_jiffies = HZ;
@@ -49,24 +48,43 @@ unsigned int  rds_sysctl_max_unacked_bytes = (16 << 20);
 
 unsigned int rds_sysctl_ping_enable = 1;
 
+static int rds_reconnect_min_handler(const struct ctl_table *table, int write,
+				     void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct ctl_table tmp = *table;
+
+	tmp.min = READ_ONCE(rds_sysctl_reconnect_min);
+	tmp.max = READ_ONCE(rds_sysctl_reconnect_max_jiffies);
+	return proc_doulongvec_ms_jiffies_minmax(&tmp, write, buffer, lenp, ppos);
+}
+
+static int rds_reconnect_max_handler(const struct ctl_table *table, int write,
+				     void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct ctl_table tmp = *table;
+
+	tmp.min = READ_ONCE(rds_sysctl_reconnect_min_jiffies);
+	return proc_doulongvec_ms_jiffies_minmax(&tmp, write, buffer, lenp, ppos);
+}
+
 static struct ctl_table rds_sysctl_rds_table[] = {
 	{
 		.procname       = "reconnect_min_delay_ms",
 		.data		= &rds_sysctl_reconnect_min_jiffies,
 		.maxlen         = sizeof(unsigned long),
 		.mode           = 0644,
-		.proc_handler   = proc_doulongvec_ms_jiffies_minmax,
-		.extra1		= &rds_sysctl_reconnect_min,
-		.extra2		= &rds_sysctl_reconnect_max_jiffies,
+		.proc_handler   = rds_reconnect_min_handler,
+		.min		= 0,
+		.max		= ULONG_MAX,
 	},
 	{
 		.procname       = "reconnect_max_delay_ms",
 		.data		= &rds_sysctl_reconnect_max_jiffies,
 		.maxlen         = sizeof(unsigned long),
 		.mode           = 0644,
-		.proc_handler   = proc_doulongvec_ms_jiffies_minmax,
-		.extra1		= &rds_sysctl_reconnect_min_jiffies,
-		.extra2		= &rds_sysctl_reconnect_max,
+		.proc_handler   = rds_reconnect_max_handler,
+		.min		= 0,
+		.max		= ULONG_MAX,
 	},
 	{
 		.procname	= "max_unacked_packets",
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 774a71f88d37..4c1d1c3696b2 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -58,9 +58,6 @@ static int rds_tcp_sndbuf_handler(const struct ctl_table *ctl, int write,
 static int rds_tcp_rcvbuf_handler(const struct ctl_table *ctl, int write,
 				  void *buffer, size_t *lenp, loff_t *fpos);
 
-static int rds_tcp_min_sndbuf = SOCK_MIN_SNDBUF;
-static int rds_tcp_min_rcvbuf = SOCK_MIN_RCVBUF;
-
 static struct ctl_table rds_tcp_sysctl_table[] = {
 #define	RDS_TCP_SNDBUF	0
 	{
@@ -69,7 +66,8 @@ static struct ctl_table rds_tcp_sysctl_table[] = {
 		.maxlen         = sizeof(int),
 		.mode           = 0644,
 		.proc_handler   = rds_tcp_sndbuf_handler,
-		.extra1		= &rds_tcp_min_sndbuf,
+		.min		= SOCK_MIN_SNDBUF,
+		.max		= INT_MAX,
 	},
 #define	RDS_TCP_RCVBUF	1
 	{
@@ -78,7 +76,8 @@ static struct ctl_table rds_tcp_sysctl_table[] = {
 		.maxlen         = sizeof(int),
 		.mode           = 0644,
 		.proc_handler   = rds_tcp_rcvbuf_handler,
-		.extra1		= &rds_tcp_min_rcvbuf,
+		.min		= SOCK_MIN_RCVBUF,
+		.max		= INT_MAX,
 	},
 };
 
@@ -764,7 +763,7 @@ static int rds_tcp_skbuf_handler(struct rds_tcp_net *rtn,
 	err = proc_dointvec_minmax(ctl, write, buffer, lenp, fpos);
 	if (err < 0) {
 		pr_warn("Invalid input. Must be >= %d\n",
-			*(int *)(ctl->extra1));
+			(int)ctl->min);
 		return err;
 	}
 
-- 
2.25.1