Re: [PATCH net-next 1/2] nexthop: Restart nexthop dump based on last dumped nexthop identifier

On Sun, Apr 18, 2021 at 10:06:41AM -0700, David Ahern wrote:

On 4/16/21 8:55 AM, Ido Schimmel wrote:

quoted

From: Ido Schimmel <idosch@nvidia.com>

Currently, a multi-part nexthop dump is restarted based on the number of
nexthops that have been dumped so far. This can result in a lot of
nexthops not being dumped when nexthops are simultaneously deleted:

 # ip nexthop | wc -l
 65536
 # ip nexthop flush
 Dump was interrupted and may be inconsistent.
 Flushed 36040 nexthops
 # ip nexthop | wc -l
 29496

Instead, restart the dump based on the nexthop identifier (fixed number)
of the last successfully dumped nexthop:

 # ip nexthop | wc -l
 65536
 # ip nexthop flush
 Dump was interrupted and may be inconsistent.
 Flushed 65536 nexthops
 # ip nexthop | wc -l
 0

Reported-by: Maksym Yaremchuk <redacted>
Tested-by: Maksym Yaremchuk <redacted>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
---
 net/ipv4/nexthop.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

Reviewed-by: David Ahern <dsahern@kernel.org>

Thanks

Any reason not to put this in -net with a Fixes tag?

I put it in the cover letter:

"Targeting at net-next since this use case never worked, the flow is
pretty obscure and such a large number of nexthops is unlikely to be
used in any real-world scenario."