[PATCH 1/5] Remove trailing NULs from network bonding sysfs interface.

From: Wagner Ferenc <hidden>
Date: 2007-12-02 12:43:18
Also in: lkml
Subsystem: bonding driver, networking drivers, the rest · Maintainers: Jay Vosburgh, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

Also remove trailing spaces from multivalued files.

This fixes output like for example:

$ od -c /sys/class/net/bond0/bonding/slaves
0000000   e   t   h   -   l   e   f   t       e   t   h   -   r   i   g
0000020   h   t      \n  \0
0000025

It mostly entails deleting '+1'-s after sprintf() calls: the return value
of sprintf is the number of characters printed, without the closing NUL,
ie. exactly what the sysfs interface requires.  The three multivalue
cases are different, because they also have to swallow back a trailing
space.

Signed-off-by: Ferenc Wagner <redacted>
---

Jay Vosburgh [off-list ref] writes:

quoted

The previous code returned '\n' (that is, a single empty line)
from most files, with one exception (xmit_hash_policy), where
it returned 'NA\n'.  This patch consolidates each file to return
nothing at all if not applicable, not even a '\n'.

I find this behaviour more usual, more useful, more efficient
and shorter to code from both sides.

[...]

quoted

+	if ((bond->params.mode == BOND_MODE_XOR) ||
+	    (bond->params.mode == BOND_MODE_8023AD)) {
		count = sprintf(buf, "%s %d\n",
			xmit_hashtype_tbl[bond->params.xmit_policy].modename,
			bond->params.xmit_policy);

	Rather than this (returning nothing if not in xor or 802.3ad
mode), I'd prefer to see this always return whatever the xmit policy is
(regardless of the mode), and remove the mode test from
bonding_store_xmit_hash().

	This would be consistent with the way the arp_ip_target option
is treated: the actual value is always displayed, even if it is not
used, and it is legal to change the value, regardless of the mode.

Okay, I'm resending the full patch series with correct subject
counters accounting for the two followup patches taking care for your
comments (4 and 5).  Please let me know if something is still missing.

Thanks,
Feri.

 drivers/net/bonding/bond_sysfs.c |   66 +++++++++++++++++--------------------
 1 files changed, 30 insertions(+), 36 deletions(-)

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index b29330d..a3f1b4a 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c

@@ -86,14 +86,13 @@ static ssize_t bonding_show_bonds(struct class *cls, char *buffer)
 			/* not enough space for another interface name */
 			if ((PAGE_SIZE - res) > 10)
 				res = PAGE_SIZE - 10;
-			res += sprintf(buffer + res, "++more++");
+			res += sprintf(buffer + res, "++more++ ");
 			break;
 		}
 		res += sprintf(buffer + res, "%s ",
 			       bond->dev->name);
 	}
-	res += sprintf(buffer + res, "\n");
-	res++;
+	if (res) buffer[res-1] = '\n'; /* eat the leftover space */
 	up_read(&(bonding_rwsem));
 	return res;
 }

@@ -235,14 +234,13 @@ static ssize_t bonding_show_slaves(struct device *d,
 			/* not enough space for another interface name */
 			if ((PAGE_SIZE - res) > 10)
 				res = PAGE_SIZE - 10;
-			res += sprintf(buf + res, "++more++");
+			res += sprintf(buf + res, "++more++ ");
 			break;
 		}
 		res += sprintf(buf + res, "%s ", slave->dev->name);
 	}
 	read_unlock(&bond->lock);
-	res += sprintf(buf + res, "\n");
-	res++;
+	if (res) buf[res-1] = '\n'; /* eat the leftover space */
 	return res;
 }

@@ -406,7 +404,7 @@ static ssize_t bonding_show_mode(struct device *d,
 
 	return sprintf(buf, "%s %d\n",
 			bond_mode_tbl[bond->params.mode].modename,
-			bond->params.mode) + 1;
+			bond->params.mode);
 }
 
 static ssize_t bonding_store_mode(struct device *d,

@@ -463,11 +461,11 @@ static ssize_t bonding_show_xmit_hash(struct device *d,
 	if ((bond->params.mode != BOND_MODE_XOR) &&
 	    (bond->params.mode != BOND_MODE_8023AD)) {
 		// Not Applicable
-		count = sprintf(buf, "NA\n") + 1;
+		count = sprintf(buf, "NA\n");
 	} else {
 		count = sprintf(buf, "%s %d\n",
 			xmit_hashtype_tbl[bond->params.xmit_policy].modename,
-			bond->params.xmit_policy) + 1;
+			bond->params.xmit_policy);
 	}
 
 	return count;

@@ -527,7 +525,7 @@ static ssize_t bonding_show_arp_validate(struct device *d,
 
 	return sprintf(buf, "%s %d\n",
 		       arp_validate_tbl[bond->params.arp_validate].modename,
-		       bond->params.arp_validate) + 1;
+		       bond->params.arp_validate);
 }
 
 static ssize_t bonding_store_arp_validate(struct device *d,

@@ -627,7 +625,7 @@ static ssize_t bonding_show_arp_interval(struct device *d,
 {
 	struct bonding *bond = to_bond(d);
 
-	return sprintf(buf, "%d\n", bond->params.arp_interval) + 1;
+	return sprintf(buf, "%d\n", bond->params.arp_interval);
 }
 
 static ssize_t bonding_store_arp_interval(struct device *d,

@@ -711,10 +709,7 @@ static ssize_t bonding_show_arp_targets(struct device *d,
 			res += sprintf(buf + res, "%u.%u.%u.%u ",
 			       NIPQUAD(bond->params.arp_targets[i]));
 	}
-	if (res)
-		res--;  /* eat the leftover space */
-	res += sprintf(buf + res, "\n");
-	res++;
+	if (res) buf[res-1] = '\n'; /* eat the leftover space */
 	return res;
 }

@@ -815,7 +810,7 @@ static ssize_t bonding_show_downdelay(struct device *d,
 {
 	struct bonding *bond = to_bond(d);
 
-	return sprintf(buf, "%d\n", bond->params.downdelay * bond->params.miimon) + 1;
+	return sprintf(buf, "%d\n", bond->params.downdelay * bond->params.miimon);
 }
 
 static ssize_t bonding_store_downdelay(struct device *d,

@@ -872,7 +867,7 @@ static ssize_t bonding_show_updelay(struct device *d,
 {
 	struct bonding *bond = to_bond(d);
 
-	return sprintf(buf, "%d\n", bond->params.updelay * bond->params.miimon) + 1;
+	return sprintf(buf, "%d\n", bond->params.updelay * bond->params.miimon);
 
 }

@@ -936,7 +931,7 @@ static ssize_t bonding_show_lacp(struct device *d,
 
 	return sprintf(buf, "%s %d\n",
 		bond_lacp_tbl[bond->params.lacp_fast].modename,
-		bond->params.lacp_fast) + 1;
+		bond->params.lacp_fast);
 }
 
 static ssize_t bonding_store_lacp(struct device *d,

@@ -992,7 +987,7 @@ static ssize_t bonding_show_miimon(struct device *d,
 {
 	struct bonding *bond = to_bond(d);
 
-	return sprintf(buf, "%d\n", bond->params.miimon) + 1;
+	return sprintf(buf, "%d\n", bond->params.miimon);
 }
 
 static ssize_t bonding_store_miimon(struct device *d,

@@ -1083,9 +1078,9 @@ static ssize_t bonding_show_primary(struct device *d,
 	struct bonding *bond = to_bond(d);
 
 	if (bond->primary_slave)
-		count = sprintf(buf, "%s\n", bond->primary_slave->dev->name) + 1;
+		count = sprintf(buf, "%s\n", bond->primary_slave->dev->name);
 	else
-		count = sprintf(buf, "\n") + 1;
+		count = sprintf(buf, "\n");
 
 	return count;
 }

@@ -1149,7 +1144,7 @@ static ssize_t bonding_show_carrier(struct device *d,
 {
 	struct bonding *bond = to_bond(d);
 
-	return sprintf(buf, "%d\n", bond->params.use_carrier) + 1;
+	return sprintf(buf, "%d\n", bond->params.use_carrier);
 }
 
 static ssize_t bonding_store_carrier(struct device *d,

@@ -1198,9 +1193,9 @@ static ssize_t bonding_show_active_slave(struct device *d,
 	read_unlock(&bond->curr_slave_lock);
 
 	if (USES_PRIMARY(bond->params.mode) && curr)
-		count = sprintf(buf, "%s\n", curr->dev->name) + 1;
+		count = sprintf(buf, "%s\n", curr->dev->name);
 	else
-		count = sprintf(buf, "\n") + 1;
+		count = sprintf(buf, "\n");
 	return count;
 }

@@ -1295,7 +1290,7 @@ static ssize_t bonding_show_mii_status(struct device *d,
 	curr = bond->curr_active_slave;
 	read_unlock(&bond->curr_slave_lock);
 
-	return sprintf(buf, "%s\n", (curr) ? "up" : "down") + 1;
+	return sprintf(buf, "%s\n", (curr) ? "up" : "down");
 }
 static DEVICE_ATTR(mii_status, S_IRUGO, bonding_show_mii_status, NULL);

@@ -1312,10 +1307,10 @@ static ssize_t bonding_show_ad_aggregator(struct device *d,
 
 	if (bond->params.mode == BOND_MODE_8023AD) {
 		struct ad_info ad_info;
-		count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.aggregator_id) + 1;
+		count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.aggregator_id);
 	}
 	else
-		count = sprintf(buf, "\n") + 1;
+		count = sprintf(buf, "\n");
 
 	return count;
 }

@@ -1334,10 +1329,10 @@ static ssize_t bonding_show_ad_num_ports(struct device *d,
 
 	if (bond->params.mode == BOND_MODE_8023AD) {
 		struct ad_info ad_info;
-		count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0: ad_info.ports) + 1;
+		count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0: ad_info.ports);
 	}
 	else
-		count = sprintf(buf, "\n") + 1;
+		count = sprintf(buf, "\n");
 
 	return count;
 }

@@ -1356,10 +1351,10 @@ static ssize_t bonding_show_ad_actor_key(struct device *d,
 
 	if (bond->params.mode == BOND_MODE_8023AD) {
 		struct ad_info ad_info;
-		count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.actor_key) + 1;
+		count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.actor_key);
 	}
 	else
-		count = sprintf(buf, "\n") + 1;
+		count = sprintf(buf, "\n");
 
 	return count;
 }

@@ -1378,10 +1373,10 @@ static ssize_t bonding_show_ad_partner_key(struct device *d,
 
 	if (bond->params.mode == BOND_MODE_8023AD) {
 		struct ad_info ad_info;
-		count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.partner_key) + 1;
+		count = sprintf(buf, "%d\n", (bond_3ad_get_active_agg_info(bond, &ad_info)) ?  0 : ad_info.partner_key);
 	}
 	else
-		count = sprintf(buf, "\n") + 1;
+		count = sprintf(buf, "\n");
 
 	return count;
 }

@@ -1403,12 +1398,11 @@ static ssize_t bonding_show_ad_partner_mac(struct device *d,
 		struct ad_info ad_info;
 		if (!bond_3ad_get_active_agg_info(bond, &ad_info)) {
 			count = sprintf(buf,"%s\n",
-					print_mac(mac, ad_info.partner_system))
-				+ 1;
+					print_mac(mac, ad_info.partner_system));
 		}
 	}
 	else
-		count = sprintf(buf, "\n") + 1;
+		count = sprintf(buf, "\n");
 
 	return count;
 }

-- 
1.4.4.4

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