[libvirt] [PATCH v2 9/9] storagepool: Alter virStoragePoolObjRemove processing

Current processing requires a "fire dance" unlocking the @obj, adding an @obj ref, locking the @pools, and relocking @obj in order to ensure proper lock ordering. This can be avoided by changing virStoragePoolObjRemove to take a @name instead of @obj. Then, we can lock the @pools list, look up the @obj by @name (like we do when adding), and remove the @obj from the list. This removes the last reference to the object effectively reaping it. NB: Since prior to calling we remove the reference to the object we cannot pass anything contained within the object (such as the obj->def or obj->def->name) because it's possible that the object could be reaped by two competing remove threads. Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; --- src/conf/virstorageobj.c | 41 +++++++++++++++++++++++++++++------------ src/conf/virstorageobj.h | 2 +- src/storage/storage_driver.c | 44 +++++++++++++++++++++++++++++--------------- src/test/test_driver.c | 30 +++++++++++++++++++----------- 4 files changed, 78 insertions(+), 39 deletions(-) diff --git a/src/conf/virstorageobj.c b/src/conf/virstorageobj.c index f48f08a64..df6febfd0 100644 --- a/src/conf/virstorageobj.c +++ b/src/conf/virstorageobj.c @@ -1034,21 +1034,31 @@ virStoragePoolObjVolumeListExport(virConnectPtr conn, } +/* + * virStoragePoolObjRemove: + * @pools: list of storage pool objects + * @name: name of storage pool to remove + * + * Find the object by name in the list, remove the object from + * each hash table in the list, and free the object. + * + * Upon entry it's expected that prior to entry any locks on + * the object related to @name will have been removed. + */ void virStoragePoolObjRemove(virStoragePoolObjListPtr pools, - virStoragePoolObjPtr obj) + const char *name) { + virStoragePoolObjPtr obj; char uuidstr[VIR_UUID_STRING_BUFLEN]; - virUUIDFormat(obj->def->uuid, uuidstr); - virObjectRef(obj); - virObjectUnlock(obj); virObjectRWLockWrite(pools); - virObjectLock(obj); - virHashRemoveEntry(pools->objs, uuidstr); - virHashRemoveEntry(pools->objsName, obj->def->name); - virObjectUnlock(obj); - virObjectUnref(obj); + if ((obj = virStoragePoolObjFindByNameLocked(pools, name))) { + virUUIDFormat(obj->def->uuid, uuidstr); + virHashRemoveEntry(pools->objs, uuidstr); + virHashRemoveEntry(pools->objsName, name); + virStoragePoolObjEndAPI(&obj); + } virObjectRWUnlock(pools); } @@ -1117,6 +1127,7 @@ virStoragePoolObjLoad(virStoragePoolObjListPtr pools, { virStoragePoolDefPtr def = NULL; virStoragePoolObjPtr obj = NULL; + char *name = NULL; if (!(def = virStoragePoolDefParseFile(path))) return NULL; @@ -1129,6 +1140,9 @@ virStoragePoolObjLoad(virStoragePoolObjListPtr pools, goto error; } + if (VIR_STRDUP(name, def->name) < 0) + goto error; + if (!(obj = virStoragePoolObjAssignDef(pools, def))) goto error; def = NULL; @@ -1144,13 +1158,16 @@ virStoragePoolObjLoad(virStoragePoolObjListPtr pools, obj->autostart = virFileLinkPointsTo(obj->autostartLink, obj->configFile); + VIR_FREE(name); + return obj; error: - if (obj) { - virStoragePoolObjRemove(pools, obj); - virObjectUnref(obj); + if (obj && name) { + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(pools, name); } + VIR_FREE(name); virStoragePoolDefFree(def); return NULL; } diff --git a/src/conf/virstorageobj.h b/src/conf/virstorageobj.h index dd7001c4b..047b08a92 100644 --- a/src/conf/virstorageobj.h +++ b/src/conf/virstorageobj.h @@ -242,7 +242,7 @@ virStoragePoolObjListNew(void); void virStoragePoolObjRemove(virStoragePoolObjListPtr pools, - virStoragePoolObjPtr obj); + const char *name); int virStoragePoolObjIsDuplicate(virStoragePoolObjListPtr pools, diff --git a/src/storage/storage_driver.c b/src/storage/storage_driver.c index 6276545eb..814e5cb97 100644 --- a/src/storage/storage_driver.c +++ b/src/storage/storage_driver.c @@ -82,19 +82,21 @@ static void storageDriverUnlock(void) /** * virStoragePoolUpdateInactive: * @poolptr: pointer to a variable holding the pool object pointer + * @name: Name of the pool * * This function is supposed to be called after a pool becomes inactive. The * function switches to the new config object for persistent pools. Inactive * pools are removed. */ static void -virStoragePoolUpdateInactive(virStoragePoolObjPtr *objptr) +virStoragePoolUpdateInactive(virStoragePoolObjPtr *objptr, + const char *name) { virStoragePoolObjPtr obj = *objptr; if (!virStoragePoolObjGetConfigFile(obj)) { - virStoragePoolObjRemove(driver->pools, obj); - virObjectUnref(obj); + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(driver->pools, name); *objptr = NULL; } else if (virStoragePoolObjGetNewDef(obj)) { virStoragePoolObjDefUseNewDef(obj); @@ -110,6 +112,7 @@ storagePoolUpdateStateCallback(virStoragePoolObjPtr obj, bool active = false; virStorageBackendPtr backend; char *stateFile; + char *name = NULL; if (!(stateFile = virFileBuildPath(driver->stateDir, def->name, ".xml"))) goto cleanup; @@ -120,6 +123,9 @@ storagePoolUpdateStateCallback(virStoragePoolObjPtr obj, goto cleanup; } + if (VIR_STRDUP(name, def->name) < 0) + goto cleanup; + /* Backends which do not support 'checkPool' are considered * inactive by default. */ if (backend->checkPool && @@ -149,12 +155,13 @@ storagePoolUpdateStateCallback(virStoragePoolObjPtr obj, virStoragePoolObjSetActive(obj, active); if (!virStoragePoolObjIsActive(obj)) - virStoragePoolUpdateInactive(&obj); + virStoragePoolUpdateInactive(&obj, name); cleanup: if (!active && stateFile) ignore_value(unlink(stateFile)); VIR_FREE(stateFile); + VIR_FREE(name); return; } @@ -707,6 +714,7 @@ storagePoolCreateXML(virConnectPtr conn, virStorageBackendPtr backend; virObjectEventPtr event = NULL; char *stateFile = NULL; + char *name = NULL; unsigned int build_flags = 0; virCheckFlags(VIR_STORAGE_POOL_CREATE_WITH_BUILD | @@ -731,6 +739,9 @@ storagePoolCreateXML(virConnectPtr conn, if ((backend = virStorageBackendForType(newDef->type)) == NULL) goto cleanup; + if (VIR_STRDUP(name, newDef->name) < 0) + goto cleanup; + if (!(obj = virStoragePoolObjAssignDef(driver->pools, newDef))) goto cleanup; newDef = NULL; @@ -776,6 +787,7 @@ storagePoolCreateXML(virConnectPtr conn, pool = virGetStoragePool(conn, def->name, def->uuid, NULL, NULL); cleanup: + VIR_FREE(name); VIR_FREE(stateFile); virStoragePoolDefFree(newDef); if (event) @@ -784,9 +796,8 @@ storagePoolCreateXML(virConnectPtr conn, return pool; error: - virStoragePoolObjRemove(driver->pools, obj); - virObjectUnref(obj); - obj = NULL; + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(driver->pools, name); goto cleanup; } @@ -800,6 +811,7 @@ storagePoolDefineXML(virConnectPtr conn, virStoragePoolDefPtr def; virStoragePoolPtr pool = NULL; virObjectEventPtr event = NULL; + char *name = NULL; virCheckFlags(0, NULL); @@ -821,15 +833,17 @@ storagePoolDefineXML(virConnectPtr conn, if (virStorageBackendForType(newDef->type) == NULL) goto cleanup; + if (VIR_STRDUP(name, newDef->name) < 0) + goto cleanup; + if (!(obj = virStoragePoolObjAssignDef(driver->pools, newDef))) goto cleanup; newDef = NULL; def = virStoragePoolObjGetDef(obj); if (virStoragePoolObjSaveDef(driver, obj, def) < 0) { - virStoragePoolObjRemove(driver->pools, obj); - virObjectUnref(obj); - obj = NULL; + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(driver->pools, name); goto cleanup; } @@ -841,6 +855,7 @@ storagePoolDefineXML(virConnectPtr conn, pool = virGetStoragePool(conn, def->name, def->uuid, NULL, NULL); cleanup: + VIR_FREE(name); if (event) virObjectEventStateQueue(driver->storageEventState, event); virStoragePoolDefFree(newDef); @@ -895,9 +910,8 @@ storagePoolUndefine(virStoragePoolPtr pool) 0); VIR_INFO("Undefining storage pool '%s'", def->name); - virStoragePoolObjRemove(driver->pools, obj); - virObjectUnref(obj); - obj = NULL; + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(driver->pools, pool->name); ret = 0; cleanup: @@ -1089,7 +1103,7 @@ storagePoolDestroy(virStoragePoolPtr pool) virStoragePoolObjSetActive(obj, false); - virStoragePoolUpdateInactive(&obj); + virStoragePoolUpdateInactive(&obj, pool->name); ret = 0; @@ -1212,7 +1226,7 @@ storagePoolRefresh(virStoragePoolPtr pool, 0); virStoragePoolObjSetActive(obj, false); - virStoragePoolUpdateInactive(&obj); + virStoragePoolUpdateInactive(&obj, pool->name); goto cleanup; } diff --git a/src/test/test_driver.c b/src/test/test_driver.c index 0a284e3d1..70509a204 100644 --- a/src/test/test_driver.c +++ b/src/test/test_driver.c @@ -4540,6 +4540,7 @@ testStoragePoolCreateXML(virConnectPtr conn, virStoragePoolDefPtr def; virStoragePoolPtr pool = NULL; virObjectEventPtr event = NULL; + char *name = NULL; virCheckFlags(0, NULL); @@ -4550,6 +4551,9 @@ testStoragePoolCreateXML(virConnectPtr conn, if (virStoragePoolObjIsDuplicate(privconn->pools, newDef, true) < 0) goto cleanup; + if (VIR_STRDUP(name, newDef->name) < 0) + goto cleanup; + if (!(obj = virStoragePoolObjAssignDef(privconn->pools, newDef))) goto cleanup; newDef = NULL; @@ -4583,6 +4587,7 @@ testStoragePoolCreateXML(virConnectPtr conn, pool = virGetStoragePool(conn, def->name, def->uuid, NULL, NULL); cleanup: + VIR_FREE(name); virStoragePoolDefFree(newDef); testObjectEventQueue(privconn, event); virStoragePoolObjEndAPI(&obj); @@ -4590,9 +4595,8 @@ testStoragePoolCreateXML(virConnectPtr conn, return pool; error: - virStoragePoolObjRemove(privconn->pools, obj); - virObjectUnref(obj); - obj = NULL; + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(privconn->pools, name); goto cleanup; } @@ -4608,6 +4612,7 @@ testStoragePoolDefineXML(virConnectPtr conn, virStoragePoolDefPtr def; virStoragePoolPtr pool = NULL; virObjectEventPtr event = NULL; + char *name = NULL; virCheckFlags(0, NULL); @@ -4622,6 +4627,9 @@ testStoragePoolDefineXML(virConnectPtr conn, if (virStoragePoolObjIsDuplicate(privconn->pools, newDef, false) < 0) goto cleanup; + if (VIR_STRDUP(name, newDef->name) < 0) + goto cleanup; + if (!(obj = virStoragePoolObjAssignDef(privconn->pools, newDef))) goto cleanup; newDef = NULL; @@ -4632,15 +4640,15 @@ testStoragePoolDefineXML(virConnectPtr conn, 0); if (testStoragePoolObjSetDefaults(obj) == -1) { - virStoragePoolObjRemove(privconn->pools, obj); - virObjectUnref(obj); - obj = NULL; + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(privconn->pools, name); goto cleanup; } pool = virGetStoragePool(conn, def->name, def->uuid, NULL, NULL); cleanup: + VIR_FREE(name); virStoragePoolDefFree(newDef); testObjectEventQueue(privconn, event); virStoragePoolObjEndAPI(&obj); @@ -4663,8 +4671,8 @@ testStoragePoolUndefine(virStoragePoolPtr pool) VIR_STORAGE_POOL_EVENT_UNDEFINED, 0); - virStoragePoolObjRemove(privconn->pools, obj); - virObjectUnref(obj); + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(privconn->pools, pool->name); testObjectEventQueue(privconn, event); return 0; @@ -4757,10 +4765,10 @@ testStoragePoolDestroy(virStoragePoolPtr pool) 0); if (!(virStoragePoolObjGetConfigFile(obj))) { - virStoragePoolObjRemove(privconn->pools, obj); - virObjectUnref(obj); - obj = NULL; + virStoragePoolObjEndAPI(&obj); + virStoragePoolObjRemove(privconn->pools, pool->name); } + ret = 0; cleanup: -- 2.13.6