From: Peter Krempa <pkrempa@redhat.com>
Date: Fri, 13 Mar 2015 17:22:04 +0100
Subject: [PATCH] qemu: Disallow concurrent block jobs on a single disk

While qemu may be prepared to do this libvirt is not. Forbid the block
ops until we fix our code.

(cherry picked from commit 51f9f03a4ca50b070c0fbfb29748d49f583e15e1)
---
 src/conf/domain_conf.h |  4 ++++
 src/qemu/qemu_domain.c | 23 +++++++++++++++++++++++
 src/qemu/qemu_domain.h |  2 ++
 src/qemu/qemu_driver.c | 28 +++++++++++++---------------
 4 files changed, 42 insertions(+), 15 deletions(-)

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index bca1b94..47bdb61 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -664,6 +664,10 @@ struct _virDomainDiskDef {
     int tray_status; /* enum virDomainDiskTray */
     int removable; /* enum virTristateSwitch */
 
+    /* ideally we want a smarter way to interlock block jobs on single qemu disk
+     * in the future, but for now we just disallow any concurrent job on a
+     * single disk */
+    bool blockjob;
     virStorageSourcePtr mirror;
     int mirrorState; /* enum virDomainDiskMirrorState */
     int mirrorJob; /* virDomainBlockJobType */
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index bd7d8a4..7c2d046 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -2757,6 +2757,29 @@ qemuDomainDetermineDiskChain(virQEMUDriverPtr driver,
     return ret;
 }
 
+
+bool
+qemuDomainDiskBlockJobIsActive(virDomainDiskDefPtr disk)
+{
+    if (disk->mirror) {
+        virReportError(VIR_ERR_BLOCK_COPY_ACTIVE,
+                       _("disk '%s' already in active block job"),
+                       disk->dst);
+
+        return true;
+    }
+
+    if (disk->blockjob) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
+                       _("disk '%s' already in active block job"),
+                       disk->dst);
+        return true;
+    }
+
+    return false;
+}
+
+
 int
 qemuDomainUpdateDeviceList(virQEMUDriverPtr driver,
                            virDomainObjPtr vm,
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index a7ebb47..41e075b 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -414,6 +414,8 @@ int qemuDomainJobInfoToParams(qemuDomainJobInfoPtr jobInfo,
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2)
     ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4);
 
+bool qemuDomainDiskBlockJobIsActive(virDomainDiskDefPtr disk);
+
 void qemuDomObjEndAPI(virDomainObjPtr *vm);
 
 #endif /* __QEMU_DOMAIN_H__ */
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 2e8c9d8..3ec057b 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4569,6 +4569,7 @@ processBlockJobEvent(virQEMUDriverPtr driver,
             disk->mirrorJob = VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN;
             ignore_value(qemuDomainDetermineDiskChain(driver, vm, disk,
                                                       true, true));
+            disk->blockjob = false;
             break;
 
         case VIR_DOMAIN_BLOCK_JOB_READY:
@@ -4584,6 +4585,7 @@ processBlockJobEvent(virQEMUDriverPtr driver,
                 VIR_DOMAIN_DISK_MIRROR_STATE_ABORT : VIR_DOMAIN_DISK_MIRROR_STATE_NONE;
             disk->mirrorJob = VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN;
             save = true;
+            disk->blockjob = false;
             break;
 
         case VIR_DOMAIN_BLOCK_JOB_LAST:
@@ -15827,6 +15829,7 @@ qemuDomainBlockPivot(virConnectPtr conn,
         disk->mirror = NULL;
         disk->mirrorState = VIR_DOMAIN_DISK_MIRROR_STATE_NONE;
         disk->mirrorJob = VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN;
+        disk->blockjob = false;
     }
     if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm) < 0)
         ret = -1;
@@ -15927,12 +15930,9 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm,
         goto endjob;
     disk = vm->def->disks[idx];
 
-    if (mode == BLOCK_JOB_PULL && disk->mirror) {
-        virReportError(VIR_ERR_BLOCK_COPY_ACTIVE,
-                       _("disk '%s' already in active block job"),
-                       disk->dst);
+    if (mode == BLOCK_JOB_PULL && qemuDomainDiskBlockJobIsActive(disk))
         goto endjob;
-    }
+
     if (mode == BLOCK_JOB_ABORT) {
         if ((flags & VIR_DOMAIN_BLOCK_JOB_ABORT_PIVOT) &&
             !(async && disk->mirror)) {
@@ -16017,6 +16017,8 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm,
         if (mode == BLOCK_JOB_ABORT && disk->mirror)
             disk->mirrorState = VIR_DOMAIN_DISK_MIRROR_STATE_NONE;
         goto endjob;
+    } else if (mode == BLOCK_JOB_PULL) {
+        disk->blockjob = true;
     }
 
  waitjob:
@@ -16269,12 +16271,8 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
     if (!device)
         goto endjob;
     disk = vm->def->disks[idx];
-    if (disk->mirror) {
-        virReportError(VIR_ERR_BLOCK_COPY_ACTIVE,
-                       _("disk '%s' already in active block job"),
-                       disk->dst);
+    if (qemuDomainDiskBlockJobIsActive(disk))
         goto endjob;
-    }
 
     if (!(virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DRIVE_MIRROR) &&
           virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKJOB_ASYNC))) {
@@ -16396,6 +16394,7 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
     disk->mirror = mirror;
     mirror = NULL;
     disk->mirrorJob = VIR_DOMAIN_BLOCK_JOB_TYPE_COPY;
+    disk->blockjob = true;
 
     if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm) < 0)
         VIR_WARN("Unable to save status on vm %s after state change",
@@ -16657,12 +16656,9 @@ qemuDomainBlockCommit(virDomainPtr dom,
                        disk->dst);
         goto endjob;
     }
-    if (disk->mirror) {
-        virReportError(VIR_ERR_BLOCK_COPY_ACTIVE,
-                       _("disk '%s' already in active block job"),
-                       disk->dst);
+
+    if (qemuDomainDiskBlockJobIsActive(disk))
         goto endjob;
-    }
     if (qemuDomainDetermineDiskChain(driver, vm, disk, false, true) < 0)
         goto endjob;
 
@@ -16785,6 +16781,8 @@ qemuDomainBlockCommit(virDomainPtr dom,
         goto endjob;
     }
 
+    disk->blockjob = true;
+
     if (mirror) {
         if (ret == 0) {
             virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);