| Message ID | 20211028131804.413243-1-maxime.chevallier@bootlin.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | ee046d9a22a4110fcf14cefa7536c265d0e6f174 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v2] net: ipconfig: Release the rtnl_lock while waiting for carrier | expand |
| Context | Check | Description |
|---|---|---|
| netdev/apply | success | Patch already applied to net-next |
| netdev/tree_selection | success | Clearly marked for net-next |
Hello: This patch was applied to netdev/net-next.git (master) by David S. Miller <davem@davemloft.net>: On Thu, 28 Oct 2021 15:18:04 +0200 you wrote: > While waiting for a carrier to come on one of the netdevices, some > devices will require to take the rtnl lock at some point to fully > initialize all parts of the link. > > That's the case for SFP, where the rtnl is taken when a module gets > detected. This prevents mounting an NFS rootfs over an SFP link. > > [...] Here is the summary with links: - [net-next,v2] net: ipconfig: Release the rtnl_lock while waiting for carrier https://git.kernel.org/netdev/net-next/c/ee046d9a22a4 You are awesome, thank you!
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c index 816d8aad5a68..9d41d5d5cd1e 100644 --- a/net/ipv4/ipconfig.c +++ b/net/ipv4/ipconfig.c @@ -262,6 +262,11 @@ static int __init ic_open_devs(void) dev->name, able, d->xid); } } + /* Devices with a complex topology like SFP ethernet interfaces needs + * the rtnl_lock at init. The carrier wait-loop must therefore run + * without holding it. + */ + rtnl_unlock(); /* no point in waiting if we could not bring up at least one device */ if (!ic_first_dev) @@ -274,9 +279,13 @@ static int __init ic_open_devs(void) msecs_to_jiffies(carrier_timeout * 1000))) { int wait, elapsed; + rtnl_lock(); for_each_netdev(&init_net, dev) - if (ic_is_init_dev(dev) && netif_carrier_ok(dev)) + if (ic_is_init_dev(dev) && netif_carrier_ok(dev)) { + rtnl_unlock(); goto have_carrier; + } + rtnl_unlock(); msleep(1); @@ -289,7 +298,6 @@ static int __init ic_open_devs(void) next_msg = jiffies + msecs_to_jiffies(20000); } have_carrier: - rtnl_unlock(); *last = NULL;
While waiting for a carrier to come on one of the netdevices, some devices will require to take the rtnl lock at some point to fully initialize all parts of the link. That's the case for SFP, where the rtnl is taken when a module gets detected. This prevents mounting an NFS rootfs over an SFP link. This means that while ipconfig waits for carriers to be detected, no SFP modules can be detected in the meantime, it's only detected after ipconfig times out. This commit releases the rtnl_lock while waiting for the carrier to come up, and re-takes it to check the for the init device and carrier status. Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> --- v2: - Following Antoine's review, release the lock earlier and only explicitely protect the for_each_netdev loop - Rebased and targeted the patch towards net-next - Dropped the Fixes tag net/ipv4/ipconfig.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)