[libvirt] [PATCH] (qemuTeardownDiskCgroup): avoid dead code
Jim Meyering
jim at meyering.net
Tue May 18 05:40:27 UTC 2010
Eric Blake wrote:
> On 05/17/2010 02:52 PM, Jim Meyering wrote:
>> It's a good thing the latter while loop condition
>> could never be true -- otherwise it'd be an infloop.
>>
>> static int qemuTeardownDiskCgroup(virCgroupPtr cgroup,
>> virDomainObjPtr vm,
>> virDomainDiskDefPtr disk)
>> {
>> char *path = disk->src;
>> int ret = -1;
>>
>> - while (path != NULL) {
>> + do {
>> virStorageFileMetadata meta;
>> int rc;
>>
>> VIR_DEBUG("Process path %s for disk", path);
> ...
>> path = meta.backingStore;
>> } while (path != NULL);
>
> Are we sure disk->src is guaranteed to be non-NULL on entry, or would
> have been better to rewrite this as while{}/*nothing*/ instead of do{}while?
You're right.
disk->src may be NULL, as attested by surrounding code that tests for it
via NULLSTR upon failure of these functions.
Thanks!
Here's a better patch:
>From 9fccf57a1c786612048964d7c5a54f5fc5e85d56 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering at redhat.com>
Date: Mon, 17 May 2010 22:50:21 +0200
Subject: [PATCH] (qemu*DiskCgroup): avoid dead code
* src/qemu/qemu_driver.c (qemuTeardownDiskCgroup): Remove
bogus empty-body while-loop.
(qemuSetupDiskCgroup): Likewise.
---
src/qemu/qemu_driver.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 16a9646..c29392d 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -2992,11 +2992,11 @@ static int qemuSetupDiskCgroup(virCgroupPtr cgroup,
if (rc < 0)
goto cleanup;
path = meta.backingStore;
- } while (path != NULL);
+ }
ret = 0;
cleanup:
return ret;
@@ -3040,11 +3040,11 @@ static int qemuTeardownDiskCgroup(virCgroupPtr cgroup,
if (rc < 0)
goto cleanup;
path = meta.backingStore;
- } while (path != NULL);
+ }
ret = 0;
cleanup:
return ret;
--
1.7.1.250.g7d1e8
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