Re: [libvirt] [PATCH v2 4/4] qemu: Forbid migration with cache != none

Migrating domains with disks using cache != none is unsafe unless the disk images are stored on coherent clustered filesystem. Thus we forbid migrating such domains unless VIR_MIGRATE_UNSAFE flags is used. --- Notes: Version 2: - use virStorageFileIsClusterFS src/qemu/qemu_driver.c | 3 ++- src/qemu/qemu_migration.c | 39 +++++++++++++++++++++++++++++++++++---- src/qemu/qemu_migration.h | 6 ++++-- 3 files changed, 41 insertions(+), 7 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 717bdf1..63a0703 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -8767,7 +8767,8 @@ qemuDomainMigrateBegin3(virDomainPtr domain, goto endjob; if (!(xml = qemuMigrationBegin(driver, vm, xmlin, dname, - cookieout, cookieoutlen))) + cookieout, cookieoutlen, + flags))) goto endjob; if ((flags & VIR_MIGRATE_CHANGE_PROTECTION)) { diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index f0af494..09494d6 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -45,6 +45,7 @@ #include "virtime.h" #include "locking/domain_lock.h" #include "rpc/virnetsocket.h" +#include "storage_file.h" #define VIR_FROM_THIS VIR_FROM_QEMU @@ -817,6 +818,29 @@ qemuMigrationIsAllowed(struct qemud_driver *driver, virDomainObjPtr vm, return true; } +static bool +qemuMigrationIsSafe(virDomainDefPtr def) +{ + int i; + + for (i = 0 ; i < def->ndisks ; i++) { + virDomainDiskDefPtr disk = def->disks[i]; + + /* shared && !readonly implies cache=none */ + if (disk->src && + disk->cachemode != VIR_DOMAIN_DISK_CACHE_DISABLE && + (disk->cachemode || !disk->shared || disk->readonly) && + virStorageFileIsClusterFS(disk->src) == 1) {