[net-next,0/6] net: deduplicate netdev name allocation

Message

Jakub Kicinski Oct. 20, 2023, 1:18 a.m. UTC

After recent fixes we have even more duplicated code in netdev name
allocation helpers. There are two complications in this code.
First, __dev_alloc_name() clobbers its output arg even if allocation
fails, forcing callers to do extra copies. Second as our experience in
commit 55a5ec9b7710 ("Revert "net: core: dev_get_valid_name is now the same as dev_alloc_name_ns"") and
commit 029b6d140550 ("Revert "net: core: maybe return -EEXIST in __dev_alloc_name"")
taught us, user space is very sensitive to the exact error codes.

Align the callers of __dev_alloc_name(), and remove some of its
complexity.

Jakub Kicinski (6):
  net: don't use input buffer of __dev_alloc_name() as a scratch space
  net: make dev_alloc_name() call dev_prep_valid_name()
  net: reduce indentation of __dev_alloc_name()
  net: trust the bitmap in __dev_alloc_name()
  net: remove dev_valid_name() check from __dev_alloc_name()
  net: remove else after return in dev_prep_valid_name()

 net/core/dev.c | 120 +++++++++++++++++++------------------------------
 1 file changed, 45 insertions(+), 75 deletions(-)