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[PULL,06/12] migration: Document handling of bdrv_is_allocated() errors

Message ID 1489416908-3771-7-git-send-email-kwolf@redhat.com
State New
Headers show

Commit Message

Kevin Wolf March 13, 2017, 2:55 p.m. UTC 
From: Eric Blake <eblake@redhat.com>

Migration is the only code left in the tree that does not react
to bdrv_is_allocated() failures.  But as there is no useful way
to react to the failure, and we are merely skipping unallocated
sectors on success, just document that our choice of handling
is intended.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 migration/block.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox

Patch

diff --git a/migration/block.c b/migration/block.c
index 1941bc2..6741228 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -276,6 +276,8 @@  static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
     if (bmds->shared_base) {
         qemu_mutex_lock_iothread();
         aio_context_acquire(blk_get_aio_context(bb));
+        /* Skip unallocated sectors; intentionally treats failure as
+         * an allocated sector */
         while (cur_sector < total_sectors &&
                !bdrv_is_allocated(blk_bs(bb), cur_sector,
                                   MAX_IS_ALLOCATED_SEARCH, &nr_sectors)) {