block/blklogwrites: Add an option for the update interval of the log superblock
This is a way to ensure that the log superblock is periodically
updated. Before, this was only done on flush requests, which may
not be enough if the VM exits abnormally, omitting the final flush.
The default interval is 4096 write requests.
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/qapi/block-core.json b/qapi/block-core.json
index d1753a2..38b3125 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -3057,13 +3057,17 @@
# @log-sector-size: sector size used in logging writes to @file, determines
# granularity of offsets and sizes of writes (default: 512)
#
+# @log-super-update-interval: interval of write requests after which the log
+# super block is updated to disk (default: 4096)
+#
# Since: 3.0
##
{ 'struct': 'BlockdevOptionsBlklogwrites',
'data': { 'file': 'BlockdevRef',
'log': 'BlockdevRef',
'*log-sector-size': 'uint32',
- '*log-append': 'bool' } }
+ '*log-append': 'bool',
+ '*log-super-update-interval': 'uint64' } }
##
# @BlockdevOptionsBlkverify:
