Re: [libvirt] [PATCH 29/38] virlog: Introduce an API mutex that serializes all setters

If the API isn't closed, a situation with 2 setters where one is about to define a set of outputs and the other is already defining a new one, may occur. By resetting all outputs, all file descriptors are closed. However, the other setter may still have a dangling reference to a file descriptor which may have already been closed. --- src/libvirt_private.syms | 2 ++ src/util/virlog.c | 15 +++++++++++++++ src/util/virlog.h | 2 ++ 3 files changed, 19 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index cc40b46..14047f5 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1741,6 +1741,8 @@ virLockSpaceReleaseResourcesForOwner; # util/virlog.h +virLogAPILock; +virLogAPIUnlock; virLogDefineFilters; virLogDefineOutputs; virLogFilterListFree; diff --git a/src/util/virlog.c b/src/util/virlog.c index 769dcec..6aa9c91 100644 --- a/src/util/virlog.c +++ b/src/util/virlog.c @@ -128,6 +128,21 @@ static void virLogOutputToFd(virLogSourcePtr src, void *data); +/* Setters need to be serialized on API entry point */ +static virMutex virLogAPIMutex; + +void +virLogAPILock(void) +{ + virMutexLock(&virLogAPIMutex); +} + +void +virLogAPIUnlock(void) +{ + virMutexUnlock(&virLogAPIMutex); +} + /* * Logs accesses must be serialized though a mutex */ diff --git a/src/util/virlog.h b/src/util/virlog.h index 1c55a48..f5c0a4f 100644 --- a/src/util/virlog.h +++ b/src/util/virlog.h @@ -203,6 +203,8 @@ extern void virLogFilterListFree(virLogFilterPtr *list, int count); * Internal logging API */ +extern void virLogAPILock(void); +extern void virLogAPIUnlock(void); extern void virLogLock(void); extern void virLogUnlock(void);