d7f2001573
tcf_vlan_init() can fail after the idr has been successfully reserved.
When this happens, every subsequent attempt to configure vlan rules using
the same idr value will systematically fail with -ENOSPC, unless the first
attempt was done using the 'replace' keyword.
# tc action add action vlan pop index 100
RTNETLINK answers: Cannot allocate memory
We have an error talking to the kernel
# tc action add action vlan pop index 100
RTNETLINK answers: No space left on device
We have an error talking to the kernel
# tc action add action vlan pop index 100
RTNETLINK answers: No space left on device
We have an error talking to the kernel
...
Fix this in tcf_vlan_init(), ensuring that tcf_idr_release() is called on
the error path when the idr has been reserved, but not yet inserted. Also,
don't test 'ovr' in the error path, to avoid a 'replace' failure implicitly
become a 'delete' that leaks refcount in act_vlan module:
# rmmod act_vlan; modprobe act_vlan
# tc action add action vlan push id 5 index 100
# tc action replace action vlan push id 7 index 100
RTNETLINK answers: Cannot allocate memory
We have an error talking to the kernel
# tc action list action vlan
#
# rmmod act_vlan
rmmod: ERROR: Module act_vlan is in use
Fixes: 4c5b9d9642c8 ("act_vlan: VLAN action rewrite to use RCU lock/unlock and update")
Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use IDR")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.