| Message ID | 1474362377-22627-1-git-send-email-nikolay@cumulusnetworks.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
From: Nikolay Aleksandrov > Sent: 20 September 2016 10:06 > When I introduced the lastuse member I made a subtle error because it was > returned as an absolute value but that is meaningless to user-space as it > doesn't allow to see how old exactly an entry is. Let's make it similar to > how the bridge returns such values and make it relative to "now" (jiffies). > This allows us to show the actual age of the entries and is much more > useful (e.g. user-space daemons can age out entries, iproute2 can display > the lastuse properly). > ... > + jiffies_to_clock_t(jiffies - > + c->mfc_un.res.lastuse), You probably need to ensure the 'age' isn't negative because 'lastuse' got updated after 'jiffies' was read and there was a clock interrupt in the gap. David
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 26253328d227..1505a0e37f44 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -2110,7 +2110,8 @@ static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if; if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) || nla_put_u64_64bit(skb, RTA_EXPIRES, - jiffies_to_clock_t(c->mfc_un.res.lastuse), + jiffies_to_clock_t(jiffies - + c->mfc_un.res.lastuse), RTA_PAD)) return -EMSGSIZE; diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 6122f9c5cc49..c35d56c5ecc9 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -2274,7 +2274,8 @@ static int __ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb, mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if; if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) || nla_put_u64_64bit(skb, RTA_EXPIRES, - jiffies_to_clock_t(c->mfc_un.res.lastuse), + jiffies_to_clock_t(jiffies - + c->mfc_un.res.lastuse), RTA_PAD)) return -EMSGSIZE;
When I introduced the lastuse member I made a subtle error because it was returned as an absolute value but that is meaningless to user-space as it doesn't allow to see how old exactly an entry is. Let's make it similar to how the bridge returns such values and make it relative to "now" (jiffies). This allows us to show the actual age of the entries and is much more useful (e.g. user-space daemons can age out entries, iproute2 can display the lastuse properly). Fixes: 43b9e1274060 ("net: ipmr/ip6mr: add support for keeping an entry age") Reported-by: Satish Ashok <sashok@cumulusnetworks.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> --- I realize that this changes the way it is exported, but since it hasn't been in a release yet and we're most probably the only users, I think it is worth fixing. This change allows user-space daemons to age out entries and also for the lastuse value to be shown properly via iproute2. net/ipv4/ipmr.c | 3 ++- net/ipv6/ip6mr.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-)