[libvirt] [PATCHv3] lxc: Fix return values of veth.c functions - complete
laine at laine.org
Thu Jul 29 18:10:50 UTC 2010
On 07/29/2010 01:53 PM, Ryota Ozaki wrote:
> On Fri, Jul 30, 2010 at 2:32 AM, Laine Stump<laine at laine.org> wrote:
>> From: Ryota Ozaki<ozaki.ryota at gmail.com>
>> Previously, the functions in src/lxc/veth.c could sometimes return
>> positive values on failure rather than -1. This made accurate error
>> reporting difficult, and led to one failure to catch an error in a
>> calling function.
>> This patch makes all the functions in veth.c consistently return 0 on
>> success, and -1 on failure. It also fixes up the callers to the veth.c
>> functions where necessary.
>> Note that this patch may be related to the bug:
>> It will not fix the bug, but should unveil what happens.
>> * po/POTFILES.in - add veth.c, which previously had no translatable strings
>> * src/lxc/lxc_controller.c
>> * src/lxc/lxc_container.c
>> * src/lxc/lxc_driver.c - fixup callers to veth.c, and remove error logs,
>> as they are now done in veth.c
>> * src/lxc/veth.c - make all functions consistently return -1 on error.
>> * src/lxc/veth.h - use ATTRIBUTE_NONNULL to protect against NULL args.
>> Changes from Ozaki's original patch:
>> 1) virAsprintf() will return the number of characters in the new
>> string on success, not 0, so we need to only set rc if it fails
>> (< 0). Assigning rc on success causes the caller to falsely believe
>> the function failed.
>> 2) lxcVmCleanup was always doing the if (WIFEXITED() ...) even
>> if waitpid had failed. I don't know if the behavior of WIFEXITED
>> is defined if waitpid fails, but all the other uses I can find
>> avoid calling WIFEXITED and WEXITSTATUS if waitpid fails, so that's
>> what I did here. Also changed to return -1 if waitpid fails or
>> WEXITSTATUS != 0.
>> 3) lxcSetupInterfaces - rather than explicitly setting rc from the
>> return of functions, since it defaults to -1, I just goto
>> error_exit if the functions return< 0. That's just cosmetic. The
>> real problem is that rc was being set from brAddInterface, which
>> returns> 0 on failure (note error log of errno from brAddInterface
>> fixed in v3).
>> 4) assigning "rc = -1" at the beginning of each veth.c function is a
>> dead store, since it will always be set by the call to virRun(). This
>> causes coverity code analysis tool to report problems.
> ACK. Thanks, Laine!
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