[libvirt] [PATCH 02/12] secrets: acquire a pidfile in the driver root directory
When we allow multiple instances of the driver for the same user
account, using a separate root directory, we need to ensure mutual
exclusion. Use a pidfile to guarantee this.
In privileged libvirtd this ends up locking
/var/run/libvirt/secrets/driver.pid
In unprivileged libvirtd this ends up locking
/run/user/$UID/libvirt/secrets/run/driver.pid
NB, the latter can vary depending on $XDG_RUNTIME_DIR
Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com>
---
src/secret/secret_driver.c | 44 +++++++++++++++++++++++++++++++-------
1 file changed, 36 insertions(+), 8 deletions(-)
diff --git a/src/secret/secret_driver.c b/src/secret/secret_driver.c
index ac85f5d195..9344948db4 100644
--- a/src/secret/secret_driver.c
+++ b/src/secret/secret_driver.c
@@ -37,6 +37,7 @@
#include "viruuid.h"
#include "virerror.h"
#include "virfile.h"
+#include "virpidfile.h"
#include "configmake.h"
#include "virstring.h"
#include "viraccessapicheck.h"
@@ -56,8 +57,12 @@ struct _virSecretDriverState {
virMutex lock;
bool privileged; /* readonly */
virSecretObjListPtr secrets;
+ char *stateDir;
char *configDir;
+ /* pid file FD, ensures two copies of the driver can't use the same root */
+ int lockFD;
+
/* Immutable pointer, self-locking APIs */
virObjectEventStatePtr secretEventState;
};
@@ -434,6 +439,10 @@ secretStateCleanup(void)
virObjectUnref(driver->secretEventState);
+ if (driver->lockFD != -1)
+ virPidFileRelease(driver->stateDir, "driver", driver->lockFD);
+
+ VIR_FREE(driver->stateDir);
secretDriverUnlock();
virMutexDestroy(&driver->lock);
VIR_FREE(driver);
@@ -447,11 +456,10 @@ secretStateInitialize(bool privileged,
virStateInhibitCallback callback ATTRIBUTE_UNUSED,
void *opaque ATTRIBUTE_UNUSED)
{
- char *base = NULL;
-
if (VIR_ALLOC(driver) < 0)
return -1;
+ driver->lockFD = -1;
if (virMutexInit(&driver->lock) < 0) {
VIR_FREE(driver);
return -1;
@@ -462,15 +470,26 @@ secretStateInitialize(bool privileged,
driver->privileged = privileged;
if (privileged) {
- if (VIR_STRDUP(base, SYSCONFDIR "/libvirt") < 0)
+ if (virAsprintf(&driver->configDir,
+ "%s/libvirt/secrets", SYSCONFDIR) < 0)
+ goto error;
+ if (virAsprintf(&driver->stateDir,
+ "%s/run/libvirt/secrets", LOCALSTATEDIR) < 0)
goto error;
} else {
- if (!(base = virGetUserConfigDirectory()))
+ VIR_AUTOFREE(char *) rundir = NULL;
+ VIR_AUTOFREE(char *) cfgdir = NULL;
+
+ if (!(cfgdir = virGetUserConfigDirectory()))
+ goto error;
+ if (virAsprintf(&driver->configDir, "%s/secrets/", cfgdir) <
0)
+ goto error;
+
+ if (!(rundir = virGetUserRuntimeDirectory()))
+ goto error;
+ if (virAsprintf(&driver->stateDir, "%s/secrets/run", rundir)
< 0)
goto error;
}
- if (virAsprintf(&driver->configDir, "%s/secrets", base) < 0)
- goto error;
- VIR_FREE(base);
if (virFileMakePathWithMode(driver->configDir, S_IRWXU) < 0) {
virReportSystemError(errno, _("cannot create config directory
'%s'"),
@@ -478,6 +497,16 @@ secretStateInitialize(bool privileged,
goto error;
}
+ if (virFileMakePathWithMode(driver->stateDir, S_IRWXU) < 0) {
+ virReportSystemError(errno, _("cannot create state directory
'%s'"),
+ driver->stateDir);
+ goto error;
+ }
+
+ if ((driver->lockFD =
+ virPidFileAcquire(driver->stateDir, "driver", true, getpid())) <
0)
+ goto error;
+
if (!(driver->secrets = virSecretObjListNew()))
goto error;
@@ -488,7 +517,6 @@ secretStateInitialize(bool privileged,
return 0;
error:
- VIR_FREE(base);
secretDriverUnlock();
secretStateCleanup();
return -1;
--
2.21.0