From: Eric Blake Date: Wed, 8 Mar 2017 21:34:29 +0000 (-0600) Subject: migration: Document handling of bdrv_is_allocated() errors X-Git-Tag: v2.9.0-rc0~8^2~6 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7d66b1fbd2112a0c1433ad7106d74c7c39e57f5f;p=users%2Fdwmw2%2Fqemu.git migration: Document handling of bdrv_is_allocated() errors 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 Signed-off-by: Kevin Wolf --- diff --git a/migration/block.c b/migration/block.c index 1941bc2402..6741228200 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)) {