| Message ID | 20181015160633.63130-4-vsementsov@virtuozzo.com |
|---|---|
| State | New |
| Headers | show |
| Series | backup-top filter driver for backup | expand |
Am 15.10.2018 um 18:06 hat Vladimir Sementsov-Ogievskiy geschrieben: > Otherwise, if we have serialized read-part in copy_range from backing > file to its parent if CoW take place, this CoW's sub-reads will > intersect with firstly created serialized read request. > > Anyway, reads should not influence on disk view, let's allow them to > intersect. > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> What about reads that internally trigger writes, such as copy-on-read? Kevin
06.11.2018 20:57, Kevin Wolf wrote: > Am 15.10.2018 um 18:06 hat Vladimir Sementsov-Ogievskiy geschrieben: >> Otherwise, if we have serialized read-part in copy_range from backing >> file to its parent if CoW take place, this CoW's sub-reads will >> intersect with firstly created serialized read request. >> >> Anyway, reads should not influence on disk view, let's allow them to >> intersect. >> >> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> > What about reads that internally trigger writes, such as copy-on-read? oops :). yes, I've to rethink this thing. > > Kevin
diff --git a/block/io.c b/block/io.c index bd9d688f8b..d4e46cb3dc 100644 --- a/block/io.c +++ b/block/io.c @@ -735,7 +735,8 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) retry = false; qemu_co_mutex_lock(&bs->reqs_lock); QLIST_FOREACH(req, &bs->tracked_requests, list) { - if (req == self || (!req->serialising && !self->serialising)) { + if (req == self || (!req->serialising && !self->serialising) || + (self->type == BDRV_TRACKED_READ && req->type == self->type)) { continue; } if (tracked_request_overlaps(req, self->overlap_offset,
Otherwise, if we have serialized read-part in copy_range from backing file to its parent if CoW take place, this CoW's sub-reads will intersect with firstly created serialized read request. Anyway, reads should not influence on disk view, let's allow them to intersect. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- block/io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)