[libvirt] [PATCH] lxc: remove redundant check
Daniel P. Berrange
berrange at redhat.com
Thu Oct 27 09:26:05 UTC 2011
On Thu, Oct 27, 2011 at 04:33:50PM +0800, Alex Jia wrote:
> On 10/27/2011 04:20 PM, Daniel P. Berrange wrote:
> >On Thu, Oct 27, 2011 at 03:18:01PM +0800, ajia at redhat.com wrote:
> >>From: Alex Jia<ajia at redhat.com>
> >>
> >>Detected by cppcheck, the previous function VIR_REALLOC_N(mounts, nmounts+1)
> >>can make sure mounts is a none null value, so it is redundant to check if
> >>mounts is null.
> >VIR_REALLOC_N is only executed inside the loop. Although it is unlikely,
> >in theory there can be zero iterations of the loop, in which case
> >'mounts' will be NULL at the point qsort is called.
> >
> >>* src/lxc/lxc_container.c: remove redundant check.
> >>
> >>Signed-off-by: Alex Jia<ajia at redhat.com>
> >>---
> >> src/lxc/lxc_container.c | 5 ++---
> >> 1 files changed, 2 insertions(+), 3 deletions(-)
> >>
> >>diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
> >>index 06ccf7e..f4879c3 100644
> >>--- a/src/lxc/lxc_container.c
> >>+++ b/src/lxc/lxc_container.c
> >>@@ -879,9 +879,8 @@ static int lxcContainerUnmountOldFS(void)
> >> }
> >> endmntent(procmnt);
> >>
> >>- if (mounts)
> >>- qsort(mounts, nmounts, sizeof(mounts[0]),
> >>- lxcContainerChildMountSort);
> >>+ qsort(mounts, nmounts, sizeof(mounts[0]),
> >>+ lxcContainerChildMountSort);
> >>
> >> for (i = 0 ; i< nmounts ; i++) {
> >> VIR_DEBUG("Umount %s", mounts[i]);
> >NACK, the check for NULL is correct
> >
> >
> >Daniel
> Hi Daniel,
> My comment is wrong, but the following judgement should make sure
> mounts is non null:
> <snip>
> if (!(mounts[nmounts++] = strdup(mntent.mnt_dir))) {
> endmntent(procmnt);
> virReportOOMError();
> return -1;
> }
> </snip>
That is ensuring that the pointer in the array element value is non-NULL.
The "if (mounts) qsort(...)" check is against the array itself, rather
than the element.
Regards,
Daniel
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