c2a7f10253
MS_SYNC flag. The system must guarantee that all writes are finished before syscalls returned. Schedule the writes in async mode, which is much faster and allows the clustering to occur. Wait for writes using VOP_FSYNC(), since we are syncing the whole file mapping. Potentially, the restriction to only apply the optimization can be relaxed by not requiring that the mapping cover whole file, as it is done by other OSes. Reported and tested by: az Reviewed by: alc MFC after: 2 weeks