Davide Caratti
f29cdfbe33
tcf_skbmod_init() can fail after the idr has been successfully reserved.
When this happens, every subsequent attempt to configure skbmod 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 skbmod swap mac index 100
RTNETLINK answers: Cannot allocate memory
We have an error talking to the kernel
# tc action add action skbmod swap mac index 100
RTNETLINK answers: No space left on device
We have an error talking to the kernel
# tc action add action skbmod swap mac index 100
RTNETLINK answers: No space left on device
We have an error talking to the kernel
...
Fix this in tcf_skbmod_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_skbmod module:
# rmmod act_skbmod; modprobe act_skbmod
# tc action add action skbmod swap mac index 100
# tc action add action skbmod swap mac continue index 100
RTNETLINK answers: File exists
We have an error talking to the kernel
# tc action replace action skbmod swap mac continue index 100
RTNETLINK answers: Cannot allocate memory
We have an error talking to the kernel
# tc action list action skbmod
#
# rmmod act_skbmod
rmmod: ERROR: Module act_skbmod is in use
Fixes: 65a206c01e ("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.