diff options
| author | Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org> | 2022-04-07 16:27:25 +0300 |
|---|---|---|
| committer | Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> | 2022-06-29 10:56:12 +0300 |
| commit | 6db7fd1ca980f8dd2fd082f13613166e170afd05 (patch) | |
| tree | 0ba7ed482f029250b27470ac63e5c52b35bda546 /qapi | |
| parent | 15df6e698719505570f8532772c2b08cb278a45a (diff) | |
block/copy-before-write: implement cbw-timeout option
In some scenarios, when copy-before-write operations lasts too long
time, it's better to cancel it.
Most useful would be to use the new option together with
on-cbw-error=break-snapshot: this way if cbw operation takes too long
time we'll just cancel backup process but do not disturb the guest too
much.
Note the tricky point of realization: we keep additional point in
bs->in_flight during block_copy operation even if it's timed-out.
Background "cancelled" block_copy operations will finish at some point
and will want to access state. We should care to not free the state in
.bdrv_close() earlier.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
[vsementsov: use bdrv_inc_in_flight()/bdrv_dec_in_flight() instead of
direct manipulation on bs->in_flight]
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Diffstat (limited to 'qapi')
| -rw-r--r-- | qapi/block-core.json | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/qapi/block-core.json b/qapi/block-core.json index 3e8456a94a..2173e7734a 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -4227,12 +4227,18 @@ # @on-cbw-error: Behavior on failure of copy-before-write operation. # Default is @break-guest-write. (Since 7.1) # +# @cbw-timeout: Zero means no limit. Non-zero sets the timeout in seconds +# for copy-before-write operation. When a timeout occurs, +# the respective copy-before-write operation will fail, and +# the @on-cbw-error parameter will decide how this failure +# is handled. Default 0. (Since 7.1) +# # Since: 6.2 ## { 'struct': 'BlockdevOptionsCbw', 'base': 'BlockdevOptionsGenericFormat', 'data': { 'target': 'BlockdevRef', '*bitmap': 'BlockDirtyBitmap', - '*on-cbw-error': 'OnCbwError' } } + '*on-cbw-error': 'OnCbwError', '*cbw-timeout': 'uint32' } } ## # @BlockdevOptions: |