Unify error reporting in the function. This simplifies the following
commit, which will not-exit-on-error behavior variant to the function.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
---
 migration/migration.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index 58fd5819bc..5489ff96df 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -748,11 +748,12 @@ process_incoming_migration_co(void *opaque)
     MigrationIncomingState *mis = migration_incoming_get_current();
     PostcopyState ps;
     int ret;
+    Error *local_err = NULL;
 
     assert(mis->from_src_file);
 
     if (compress_threads_load_setup(mis->from_src_file)) {
-        error_report("Failed to setup decompress threads");
+        error_setg(&local_err, "Failed to setup decompress threads");
         goto fail;
     }
 
@@ -789,16 +790,12 @@ process_incoming_migration_co(void *opaque)
     }
 
     if (ret < 0) {
-        if (migrate_has_error(s)) {
-            WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
-                error_report_err(error_copy(s->error));
-            }
-        }
-        error_report("load of migration failed: %s", strerror(-ret));
+        error_setg(&local_err, "load of migration failed: %s", strerror(-ret));
         goto fail;
     }
 
     if (colo_incoming_co() < 0) {
+        error_setg(&local_err, "colo incoming failed");
         goto fail;
     }
 
@@ -809,6 +806,12 @@ fail:
                       MIGRATION_STATUS_FAILED);
     migration_incoming_state_destroy();
 
+    if (migrate_has_error(s)) {
+        WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
+            error_report_err(error_copy(s->error));
+        }
+    }
+    error_report_err(local_err);
     migrate_error_free(s);
     exit(EXIT_FAILURE);
 }
-- 
2.34.1

On Mon, Apr 29, 2024 at 10:14:25PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> Unify error reporting in the function. This simplifies the following
> commit, which will not-exit-on-error behavior variant to the function.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> Reviewed-by: Fabiano Rosas <farosas@suse.de>
> ---
>  migration/migration.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 58fd5819bc..5489ff96df 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -748,11 +748,12 @@ process_incoming_migration_co(void *opaque)
>      MigrationIncomingState *mis = migration_incoming_get_current();
>      PostcopyState ps;
>      int ret;
> +    Error *local_err = NULL;
>  
>      assert(mis->from_src_file);
>  
>      if (compress_threads_load_setup(mis->from_src_file)) {
> -        error_report("Failed to setup decompress threads");
> +        error_setg(&local_err, "Failed to setup decompress threads");
>          goto fail;
>      }
>  
> @@ -789,16 +790,12 @@ process_incoming_migration_co(void *opaque)
>      }
>  
>      if (ret < 0) {
> -        if (migrate_has_error(s)) {
> -            WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
> -                error_report_err(error_copy(s->error));
> -            }
> -        }
> -        error_report("load of migration failed: %s", strerror(-ret));
> +        error_setg(&local_err, "load of migration failed: %s", strerror(-ret));
>          goto fail;
>      }
>  
>      if (colo_incoming_co() < 0) {
> +        error_setg(&local_err, "colo incoming failed");
>          goto fail;
>      }
>  
> @@ -809,6 +806,12 @@ fail:
>                        MIGRATION_STATUS_FAILED);
>      migration_incoming_state_destroy();
>  
> +    if (migrate_has_error(s)) {
> +        WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
> +            error_report_err(error_copy(s->error));
> +        }
> +    }
> +    error_report_err(local_err);

Here migrate_has_error() will always return true?  If so we can drop it.

Meanwhile, IMHO it's easier we simply always keep the earliest error we see
and report that only, local_err is just one of the errors and whoever
reaches first will be reported.  Something like:

  migrate_set_error(local_err);
  WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
      error_report_err(error_copy(s->error));
  }
  exit(EXIT_FAILURE);

Then when with the exit-on-error thing:

  migrate_set_error(local_err);
  if (exit_on_error) {
    WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
      error_report_err(error_copy(s->error));
    }
    exit(EXIT_FAILURE);
  }

Would this looks slightly cleaner?

-- 
Peter Xu

On 29.04.24 22:39, Peter Xu wrote:
> On Mon, Apr 29, 2024 at 10:14:25PM +0300, Vladimir Sementsov-Ogievskiy wrote:
>> Unify error reporting in the function. This simplifies the following
>> commit, which will not-exit-on-error behavior variant to the function.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
>> Reviewed-by: Fabiano Rosas <farosas@suse.de>
>> ---
>>   migration/migration.c | 17 ++++++++++-------
>>   1 file changed, 10 insertions(+), 7 deletions(-)
>>
>> diff --git a/migration/migration.c b/migration/migration.c
>> index 58fd5819bc..5489ff96df 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -748,11 +748,12 @@ process_incoming_migration_co(void *opaque)
>>       MigrationIncomingState *mis = migration_incoming_get_current();
>>       PostcopyState ps;
>>       int ret;
>> +    Error *local_err = NULL;
>>   
>>       assert(mis->from_src_file);
>>   
>>       if (compress_threads_load_setup(mis->from_src_file)) {
>> -        error_report("Failed to setup decompress threads");
>> +        error_setg(&local_err, "Failed to setup decompress threads");
>>           goto fail;
>>       }
>>   
>> @@ -789,16 +790,12 @@ process_incoming_migration_co(void *opaque)
>>       }
>>   
>>       if (ret < 0) {
>> -        if (migrate_has_error(s)) {
>> -            WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
>> -                error_report_err(error_copy(s->error));
>> -            }
>> -        }
>> -        error_report("load of migration failed: %s", strerror(-ret));
>> +        error_setg(&local_err, "load of migration failed: %s", strerror(-ret));
>>           goto fail;
>>       }
>>   
>>       if (colo_incoming_co() < 0) {
>> +        error_setg(&local_err, "colo incoming failed");
>>           goto fail;
>>       }
>>   
>> @@ -809,6 +806,12 @@ fail:
>>                         MIGRATION_STATUS_FAILED);
>>       migration_incoming_state_destroy();
>>   
>> +    if (migrate_has_error(s)) {
>> +        WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
>> +            error_report_err(error_copy(s->error));
>> +        }
>> +    }
>> +    error_report_err(local_err);
> 
> Here migrate_has_error() will always return true?  If so we can drop it.
> 
> Meanwhile, IMHO it's easier we simply always keep the earliest error we see
> and report that only, local_err is just one of the errors and whoever
> reaches first will be reported.  Something like:
> 
>    migrate_set_error(local_err);
>    WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
>        error_report_err(error_copy(s->error));
>    }
>    exit(EXIT_FAILURE);
> 
> Then when with the exit-on-error thing:
> 
>    migrate_set_error(local_err);
>    if (exit_on_error) {
>      WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
>        error_report_err(error_copy(s->error));
>      }
>      exit(EXIT_FAILURE);
>    }
> 
> Would this looks slightly cleaner?
> 

Yes, looks better, will do so

-- 
Best regards,
Vladimir