Re: [PATCH 4/4] bonding: add sysfs files to display tlb and alb hash table contents

[Jay Vosburgh <fubar@us.ibm.com>]

Andy Gospodarek <andy@greyhouse.net> wrote:

>bonding: add sysfs files to display tlb and alb hash table contents

	Isn't it considered bad form to have sysfs files that kick out
large amounts of data like this?  Not that I think this is a bad
facility to have, just checking on the mechanism.

>While debugging some problems with alb (mode 6) bonding I realized that
>being able to output the contents of both hash tables would be helpful.
>This is what the output looks like for the two files:
>
>device  load
>eth1    491
>eth2    491
>hash device   last device   tx bytes       load        next previous
>2    eth1     eth1          2254           491         0    0
>3    eth2     eth2          2744           491         0    0
>6             eth2          0              488         0    0
>8             eth2          0              461698      0    0
>1b            eth2          0              249         0    0
>eb            eth2          0              21          0    0
>ff            eth2          0              22          0    0
>
>hash ip_src          ip_dst          mac_dst           slave assign ntt
>2    10.0.3.2        10.0.3.11       00:e0:81:71:ee:a9 eth1  1      0
>3    10.0.3.2        10.0.3.10       00:e0:81:71:ee:a9 eth2  1      0
>8    10.0.3.2        10.0.3.1        00:e0:81:71:ee:a9 eth2  1      0
>
>These were a great help debugging the fixes I have just posted and they
>might be helpful for others, so I decided to include them in my
>patchset.
>
>Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
>
>---
> drivers/net/bonding/bond_alb.c   |   61 ++++++++++++++++++++++++++++++++++++++
> drivers/net/bonding/bond_alb.h   |    2 +
> drivers/net/bonding/bond_sysfs.c |   40 +++++++++++++++++++++++++
> 3 files changed, 103 insertions(+), 0 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
>index 7db8835..4e930e3 100644
>--- a/drivers/net/bonding/bond_alb.c
>+++ b/drivers/net/bonding/bond_alb.c
>@@ -778,6 +778,67 @@ static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
> 	return tx_slave;
> }
>
>+int rlb_print_rx_hashtbl(struct bonding *bond, char *buf)
>+{
>+	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
>+	struct rlb_client_info *client_info;
>+	u32 hash_index;
>+	u32 count = 0;
>+	
>+	_lock_rx_hashtbl(bond);
>+
>+	count = sprintf(buf, "hash ip_src          ip_dst          mac_dst           slave assign ntt\n");
>+	hash_index = bond_info->rx_hashtbl_head;
>+	for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
>+		client_info = &(bond_info->rx_hashtbl[hash_index]);
>+		count += sprintf(buf + count,"%-4x %-15pi4 %-15pi4 %pM %-5s %-6d %d\n",
>+				 hash_index,
>+				 &client_info->ip_src,
>+				 &client_info->ip_dst,
>+				 client_info->mac_dst,
>+				 client_info->slave->dev->name,
>+				 client_info->assigned,
>+				 client_info->ntt);
>+	}
>+
>+	_unlock_rx_hashtbl(bond);
>+	return count;
>+}
>+
>+int tlb_print_tx_hashtbl(struct bonding *bond, char *buf)
>+{
>+	struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
>+	u32 hash_index;
>+	u32 count = 0;
>+	struct slave *slave;
>+	int i;
>+	
>+	_lock_tx_hashtbl(bond);
>+
>+	count += sprintf(buf, "device  load\n");
>+	bond_for_each_slave(bond, slave, i) {
>+		struct tlb_slave_info *slave_info = &(SLAVE_TLB_INFO(slave));
>+		count += sprintf(buf + count,"%-7s %d\n",slave->dev->name,slave_info->load);
>+	}
>+	count += sprintf(buf + count, "hash device   last device   tx bytes       load        next previous\n");
>+	for (hash_index = 0; hash_index < TLB_HASH_TABLE_SIZE; hash_index++) {
>+		struct tlb_client_info *client_info = &(bond_info->tx_hashtbl[hash_index]);
>+		if (client_info->tx_slave || client_info->last_slave) {
>+			count += sprintf(buf + count,"%-4x %-8s %-13s %-14d %-11d %-4x %d\n",
>+					 hash_index,
>+					 (client_info->tx_slave) ? client_info->tx_slave->dev->name : "",
>+					 (client_info->last_slave) ? client_info->last_slave->dev->name : "",
>+					 client_info->tx_bytes,
>+					 client_info->load_history,
>+					 (client_info->next != TLB_NULL_INDEX) ? client_info->next : 0,
>+					 (client_info->prev != TLB_NULL_INDEX) ? client_info->prev : 0);
>+		}
>+	}
>+
>+	_unlock_tx_hashtbl(bond);
>+	return count;
>+}
>+
> /* Caller must hold rx_hashtbl lock */
> static void rlb_init_table_entry(struct rlb_client_info *entry)
> {
>diff --git a/drivers/net/bonding/bond_alb.h b/drivers/net/bonding/bond_alb.h
>index b65fd29..8543447 100644
>--- a/drivers/net/bonding/bond_alb.h
>+++ b/drivers/net/bonding/bond_alb.h
>@@ -132,5 +132,7 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev);
> void bond_alb_monitor(struct work_struct *);
> int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr);
> void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id);
>+int rlb_print_rx_hashtbl(struct bonding *bond, char *buf);
>+int tlb_print_tx_hashtbl(struct bonding *bond, char *buf);
> #endif /* __BOND_ALB_H__ */
>
>diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
>index 55bf34f..1123e1f 100644
>--- a/drivers/net/bonding/bond_sysfs.c
>+++ b/drivers/net/bonding/bond_sysfs.c
>@@ -1480,6 +1480,44 @@ static ssize_t bonding_show_ad_partner_mac(struct device *d,
> static DEVICE_ATTR(ad_partner_mac, S_IRUGO, bonding_show_ad_partner_mac, NULL);
>
>
>+/*
>+ * Show current tlb/alb tx hash table.
>+ */
>+static ssize_t bonding_show_tlb_tx_hash(struct device *d,
>+					   struct device_attribute *attr,
>+					   char *buf)
>+{
>+	int count = 0;
>+	struct bonding *bond = to_bond(d);
>+
>+	if (bond->params.mode == BOND_MODE_ALB ||
>+	    bond->params.mode == BOND_MODE_TLB) {
>+		count = tlb_print_tx_hashtbl(bond, buf);
>+	}
>+
>+	return count;
>+}
>+static DEVICE_ATTR(tlb_tx_hash, S_IRUGO, bonding_show_tlb_tx_hash, NULL);

	Should the mode here be S_IRUSR (0400, instead of 0444)?
Otherwise, a nefarious user could "while 1 cat /sys/.../tlb_tx_hash" and
keep the hash table lock fairly busy.  Since the lock is acquired for
every packet on tx, that's probably a bad thing.

>+
>+/*
>+ * Show current alb rx hash table.
>+ */
>+static ssize_t bonding_show_alb_rx_hash(struct device *d,
>+					   struct device_attribute *attr,
>+					   char *buf)
>+{
>+	int count = 0;
>+	struct bonding *bond = to_bond(d);
>+
>+	if (bond->params.mode == BOND_MODE_ALB) {
>+		count = rlb_print_rx_hashtbl(bond, buf);
>+	}
>+
>+	return count;
>+}
>+static DEVICE_ATTR(alb_rx_hash, S_IRUGO, bonding_show_alb_rx_hash, NULL);

	Same comment as for the mode of the tlb_tx_hash, although the rx
hash table lock is much more lightly used, so it might not be a real
problem.

>
> static struct attribute *per_bond_attrs[] = {
> 	&dev_attr_slaves.attr,
>@@ -1505,6 +1543,8 @@ static struct attribute *per_bond_attrs[] = {
> 	&dev_attr_ad_actor_key.attr,
> 	&dev_attr_ad_partner_key.attr,
> 	&dev_attr_ad_partner_mac.attr,
>+	&dev_attr_alb_rx_hash.attr,
>+	&dev_attr_tlb_tx_hash.attr,
> 	NULL,
> };
>
>-- 
>1.5.5.6
>

	-J

---
	-Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com