[PATCH] Rework qemuMigrationDstPrecreateDisk()

Jonathon Jongsma jjongsma at redhat.com
Tue Feb 9 21:55:20 UTC 2021


On Sat,  6 Feb 2021 11:11:11 +0800
Yi Li <yili at winhong.com> wrote:

> 'conn' vairable which are used only inside the func. Let's declare
> inside the func body to make that obvious.
> Use g_autofree to allow removal of 'cleanup:' and the 'ret' variable.

It may be worth referencing the commit that introduced this
inconsistency:
accdc0e7730739f398e392c23bc8380d3574a878


> 
> Signed-off-by: Yi Li <yili at winhong.com>
> ---
>  src/qemu/qemu_migration.c | 68
> +++++++++++++++------------------------ 1 file changed, 26
> insertions(+), 42 deletions(-)
> 
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index f44d31c971..6bb0677f86 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
> @@ -169,15 +169,15 @@
> qemuMigrationSrcRestoreDomainState(virQEMUDriverPtr driver,
> virDomainObjPtr vm) 
>  static int
> -qemuMigrationDstPrecreateDisk(virConnectPtr *conn,
> -                              virDomainDiskDefPtr disk,
> +qemuMigrationDstPrecreateDisk(virDomainDiskDefPtr disk,
>                                unsigned long long capacity)
>  {
> -    int ret = -1;
> -    virStoragePoolPtr pool = NULL;
> -    virStorageVolPtr vol = NULL;
> -    char *volName = NULL, *basePath = NULL;
> -    char *volStr = NULL;
> +    g_autoptr(virConnect) conn = NULL;
> +    g_autoptr(virStoragePool) pool = NULL;
> +    g_autoptr(virStorageVol) vol = NULL;
> +    char *volName = NULL;
> +    g_autofree char *basePath = NULL;
> +    g_autofree char *volStr = NULL;


Personally, I feel that this commit is doing a bit too much. I'd prefer
to split out all of this auto pointer refactoring that is unrelated to
the 'conn' argument into a separate preparatory commit. 


>      g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER;
>      const char *format = NULL;
>      unsigned int flags = 0;
> @@ -198,32 +198,28 @@ qemuMigrationDstPrecreateDisk(virConnectPtr
> *conn, virReportError(VIR_ERR_INVALID_ARG,
>                             _("malformed disk path: %s"),
>                             disk->src->path);
> -            goto cleanup;
> +            return -1;
>          }
>  
>          *volName = '\0';
>          volName++;
>  
> -        if (!*conn) {
> -            if (!(*conn = virGetConnectStorage()))
> -                goto cleanup;
> -        }
> +        if (!(conn = virGetConnectStorage()))
> +            return -1;
>  
> -        if (!(pool = virStoragePoolLookupByTargetPath(*conn,
> basePath)))
> -            goto cleanup;
> +        if (!(pool = virStoragePoolLookupByTargetPath(conn,
> basePath)))
> +            return -1;
>          format = virStorageFileFormatTypeToString(disk->src->format);
>          if (disk->src->format == VIR_STORAGE_FILE_QCOW2)
>              flags |= VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA;
>          break;
>  
>      case VIR_STORAGE_TYPE_VOLUME:
> -        if (!*conn) {
> -            if (!(*conn = virGetConnectStorage()))
> -                goto cleanup;
> -        }
> +        if (!(conn = virGetConnectStorage()))
> +            return -1;
>  
> -        if (!(pool = virStoragePoolLookupByName(*conn,
> disk->src->srcpool->pool)))
> -            goto cleanup;
> +        if (!(pool = virStoragePoolLookupByName(conn,
> disk->src->srcpool->pool)))
> +            return -1;
>          format = virStorageFileFormatTypeToString(disk->src->format);
>          volName = disk->src->srcpool->volume;
>          if (disk->src->format == VIR_STORAGE_FILE_QCOW2)
> @@ -245,13 +241,13 @@ qemuMigrationDstPrecreateDisk(virConnectPtr
> *conn, _("cannot precreate storage for disk type '%s'"),
>                         virStorageTypeToString(disk->src->type));
>          goto cleanup;
> +        return -1;

^ This line doesn't appear to be reachable. It looks like you
forgot to remove the goto?

>      }
>  
>      if ((vol = virStorageVolLookupByName(pool, volName))) {
>          VIR_DEBUG("Skipping creation of already existing volume of
> name '%s'", volName);
> -        ret = 0;
> -        goto cleanup;
> +        return 0;
>      }
>  
>      virBufferAddLit(&buf, "<volume>\n");
> @@ -269,19 +265,13 @@ qemuMigrationDstPrecreateDisk(virConnectPtr
> *conn, if (!(volStr = virBufferContentAndReset(&buf))) {
>          virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>                         _("unable to create volume XML"));
> -        goto cleanup;
> +        return -1;
>      }
>  
>      if (!(vol = virStorageVolCreateXML(pool, volStr, flags)))
> -        goto cleanup;
> +        return -1;
>  
> -    ret = 0;
> - cleanup:
> -    VIR_FREE(basePath);
> -    VIR_FREE(volStr);
> -    virObjectUnref(vol);
> -    virObjectUnref(pool);
> -    return ret;
> +    return 0;
>  }
>  
>  static bool
> @@ -313,9 +303,7 @@ qemuMigrationDstPrecreateStorage(virDomainObjPtr
> vm, const char **migrate_disks,
>                                   bool incremental)
>  {
> -    int ret = -1;
>      size_t i = 0;
> -    virConnectPtr conn = NULL;
>  
>      if (!nbd || !nbd->ndisks)
>          return 0;
> @@ -332,7 +320,7 @@ qemuMigrationDstPrecreateStorage(virDomainObjPtr
> vm, virReportError(VIR_ERR_INTERNAL_ERROR,
>                             _("unable to find disk by target: %s"),
>                             nbd->disks[i].target);
> -            goto cleanup;
> +            return -1;
>          }
>  
>          if (disk->src->type == VIR_STORAGE_TYPE_NVME) {
> @@ -352,20 +340,16 @@
> qemuMigrationDstPrecreateStorage(virDomainObjPtr vm,
> virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", _("pre-creation
> of storage targets for incremental " "storage migration is not
> supported"));
> -            goto cleanup;
> +            return -1;
>          }
>  
>          VIR_DEBUG("Proceeding with disk source %s",
> NULLSTR(diskSrcPath)); 
> -        if (qemuMigrationDstPrecreateDisk(&conn,
> -                                          disk,
> nbd->disks[i].capacity) < 0)
> -            goto cleanup;
> +        if (qemuMigrationDstPrecreateDisk(disk,
> nbd->disks[i].capacity) < 0)
> +            return -1;
>      }
>  
> -    ret = 0;
> - cleanup:
> -    virObjectUnref(conn);
> -    return ret;
> +    return 0;
>  }
>  
>  




More information about the libvir-list mailing list