From 329a0c2d4967b6dac1530c010856119447385457 Mon Sep 17 00:00:00 2001 From: John Snow Date: Tue, 25 Sep 2018 22:34:31 +0100 Subject: [PATCH 28/28] blockdev: document transactional shortcomings RH-Author: John Snow Message-id: <20180925223431.24791-26-jsnow@redhat.com> Patchwork-id: 82286 O-Subject: [RHEL8/rhel qemu-kvm PATCH 25/25] blockdev: document transactional shortcomings Bugzilla: 1632939 RH-Acked-by: Jeffrey Cody RH-Acked-by: Max Reitz RH-Acked-by: Kevin Wolf Presently only the backup job really guarantees what one would consider transactional semantics. To guard against someone helpfully adding them in the future, document that there are shortcomings in the model that would need to be audited at that time. Signed-off-by: John Snow Message-id: 20180906130225.5118-17-jsnow@redhat.com Reviewed-by: Jeff Cody Reviewed-by: Max Reitz Signed-off-by: Max Reitz (cherry picked from commit 66da04ddd3dcb8c61ee664b6faced132da002006) Signed-off-by: John Snow Signed-off-by: Danilo C. L. de Paula --- blockdev.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/blockdev.c b/blockdev.c index bf026d2..b8e4b0d 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2292,7 +2292,13 @@ static const BlkActionOps actions[] = { .instance_size = sizeof(BlockDirtyBitmapState), .prepare = block_dirty_bitmap_disable_prepare, .abort = block_dirty_bitmap_disable_abort, - } + }, + /* Where are transactions for MIRROR, COMMIT and STREAM? + * Although these blockjobs use transaction callbacks like the backup job, + * these jobs do not necessarily adhere to transaction semantics. + * These jobs may not fully undo all of their actions on abort, nor do they + * necessarily work in transactions with more than one job in them. + */ }; /** -- 1.8.3.1