[PATCH v3 net-next 0/2] net: print net_device name/state more often

[Veaceslav Falico <vfalico@gmail.com>]

Hi,

Currently we use net_device->name only if it's the NETREG_REGISTERED
reg_state, otherwise we return "(unregistered device)".

However, we always populate net_device->name on creation, so it's always
available to us for use. The only caveat is that we might have a name like
"eth%d", in which case we cannot use it as it might change in the future.

Also, the net_device might not be NETREG_UNREGISTERED when the function is
called (_UNINITIALIZED, _UNREGISTERING, _RELEASED, _DUMMY), so it's
misleading.

So, a better way would be to always return the dev->name in netdev_name(),
unless it's in the form of "eth%d" or it's empty, then return
"unnamed net_device". This way we'll always return the name in
NETREG_REGISTERED reg_state, and also return it in other states, when
possible.

Also, to be more verbose on non-NETREG_REGISTERED states, add a function
netdev_reg_state(), which returns a string describing the state, and use it
in netdev_printk()-related functions. If the dev is in NETREG_REGISTERED
state then a void string is regurned and, thus, nothing changes.

After these two patches we'll have the same behaviour in the usual cases,
and more verbose in non-standardad/buggy ones.

v2->v3:
Correct the string for _UNINITIALIZED and warn on a bad reg_state,
per Joe Perches's comments.

v1->v2:
As Tom Gundersen suggested, there might be a case when we have an empty
string as a name for a device, so account this also and return "unnamed
device" for that case too.

CC: "David S. Miller" <davem@davemloft.net>
CC: Jason Baron <jbaron@akamai.com>
CC: Eric Dumazet <edumazet@google.com>
CC: Vlad Yasevich <vyasevic@redhat.com>
CC: stephen hemminger <stephen@networkplumber.org>
CC: Jerry Chu <hkchu@google.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Joe Perches <joe@perches.com>
Signed-off-by: Veaceslav Falico <vfalico@gmail.com>

---
 include/linux/netdevice.h | 22 +++++++++++++++++++---
 lib/dynamic_debug.c       |  8 +++++---
 net/core/dev.c            |  8 +++++---
 3 files changed, 29 insertions(+), 9 deletions(-)