[libvirt] [PATCH] LXC fix virCgroupGetValueStr on handling a string terminated with '\n'

Hi there, A cgroup file returns integer value terminated with '\n' and remaining it has sometimes harmful effects, for example it leads virStrToLong_ull failed. The fix just gets rid of '\n' if included. It first has been in virCgroupGetFreezerState, but now merged in virCgroupGetValueStr to cover every functions using virCgroupGetValueStr. I'm not sure that that behavior is from the beginning or changed in a recent kernel, but the fix should work even though anyway. BTW, by the defect I first got the following error and it made me confused. # virsh -c lxc:/// dominfo 4930 Id: 4930 Name: lxc UUID: 084369a0-956a-3010-fc37-ddeb4d627e69 OS Type: exe Autostart: disable error: this function is not supported by the hypervisor: virNodeGetSecurityModel The really error happens in lxcDomainGetInfo, so I guess something is wrong with internal error propagation. Anyone know this unexpected behavior? Thanks, ozaki-r From: Ryota Ozaki <ozaki.ryota(a)gmail.com&gt; Date: Fri, 16 Oct 2009 00:13:41 +0900 Subject: [PATCH] LXC fix virCgroupGetValueStr on handling a string terminated with '\n' * src/util/cgroup.c: get rid of '\n' from the return value of virCgroupGetValueStr --- src/util/cgroup.c | 12 +++++------- 1 files changed, 5 insertions(+), 7 deletions(-) diff --git a/src/util/cgroup.c b/src/util/cgroup.c index f728a2f..f0e2960 100644 --- a/src/util/cgroup.c+++ b/src/util/cgroup.c @@ -309,6 +309,10 @@ static int virCgroupGetValueStr(virCgroupPtr group, DEBUG("Failed to read %s: %m\n", keypath); rc = -errno; } else { + /* Terminated with '\n' has sometimes harmful effects to the caller */ + char *p = strchr((const char *)value, '\n'); + if (p) *p = '\0'; + rc = 0; } @@ -969,13 +973,7 @@ int virCgroupSetFreezerState(virCgroupPtr group, const char *state) int virCgroupGetFreezerState(virCgroupPtr group, char **state) { - int ret; - ret = virCgroupGetValueStr(group, + return virCgroupGetValueStr(group, VIR_CGROUP_CONTROLLER_CPU, "freezer.state", state); - if (ret == 0) { - char *p = strchr(*state, '\n'); - if (p) *p = '\0'; - } - return ret; } -- 1.6.2.5