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| author | Steve Sistare <steven.sistare@oracle.com> | 2023-10-18 06:03:36 -0700 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2023-10-20 08:51:41 +0200 |
| commit | c8a7fc5179c649eed1d4286776a23e8a1a183cdc (patch) | |
| tree | c5fb90795cb604c07815f6c4321e33ab93706cd3 /include/migration | |
| parent | 04131e00097c5b85f96af6a66b1c009446c90ec1 (diff) | |
| download | qemu-c8a7fc5179c649eed1d4286776a23e8a1a183cdc.zip qemu-c8a7fc5179c649eed1d4286776a23e8a1a183cdc.tar.gz qemu-c8a7fc5179c649eed1d4286776a23e8a1a183cdc.tar.bz2 | |
migration: simplify blockers
Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_blocker, migration code can free the Error
and clear the client handle, simplifying client code. It also simplifies
the migrate_del_blocker call site.
In addition, this is a pre-requisite for a proposed future patch that would
add a mode argument to migration requests to support live update, and
maintain a list of blockers for each mode. A blocker may apply to a single
mode or to multiple modes, and passing Error** will allow one Error object
to be registered for multiple modes.
No functional change.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Tested-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>
Diffstat (limited to 'include/migration')
| -rw-r--r-- | include/migration/blocker.h | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/include/migration/blocker.h b/include/migration/blocker.h index 9cebe2b..b048f30 100644 --- a/include/migration/blocker.h +++ b/include/migration/blocker.h @@ -17,19 +17,23 @@ /** * @migrate_add_blocker - prevent migration from proceeding * - * @reason - an error to be returned whenever migration is attempted + * @reasonp - address of an error to be returned whenever migration is attempted * * @errp - [out] The reason (if any) we cannot block migration right now. * * @returns - 0 on success, -EBUSY/-EACCES on failure, with errp set. + * + * *@reasonp is freed and set to NULL if failure is returned. + * On success, the caller must not free @reasonp, except by + * calling migrate_del_blocker. */ -int migrate_add_blocker(Error *reason, Error **errp); +int migrate_add_blocker(Error **reasonp, Error **errp); /** * @migrate_add_blocker_internal - prevent migration from proceeding without * only-migrate implications * - * @reason - an error to be returned whenever migration is attempted + * @reasonp - address of an error to be returned whenever migration is attempted * * @errp - [out] The reason (if any) we cannot block migration right now. * @@ -38,14 +42,20 @@ int migrate_add_blocker(Error *reason, Error **errp); * Some of the migration blockers can be temporary (e.g., for a few seconds), * so it shouldn't need to conflict with "-only-migratable". For those cases, * we can call this function rather than @migrate_add_blocker(). + * + * *@reasonp is freed and set to NULL if failure is returned. + * On success, the caller must not free @reasonp, except by + * calling migrate_del_blocker. */ -int migrate_add_blocker_internal(Error *reason, Error **errp); +int migrate_add_blocker_internal(Error **reasonp, Error **errp); /** - * @migrate_del_blocker - remove a blocking error from migration + * @migrate_del_blocker - remove a blocking error from migration and free it. + * + * @reasonp - address of the error blocking migration * - * @reason - the error blocking migration + * This function frees *@reasonp and sets it to NULL. */ -void migrate_del_blocker(Error *reason); +void migrate_del_blocker(Error **reasonp); #endif |