Andrew Morton wrote: > On Tue, 14 Jul 2009 17:05:54 +0300 > Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote: > >> Speed up ext3 recovery mount time by not sync'ing the >> block device. Instead place all dirty buffers into the >> I/O queue and add a write barrier. This ensures that >> no subsequent write will reach the disk before all the >> recovery writes, but that we do not have to wait for the >> I/O. >> >> Note that ext3 reads sectors the correct way: through the >> buffer cache, so there is no risk of reading old metadata. > > hm. The change seems reasonable to me. afaict it leaves no timing > windows during which another crash could muck things up. > > As long as those write barriers actually work. Do they? For all > conceivable devices and IO schedulers? Good point .... for many devices the barriers will fail, but by then I think this code has already moved on, right? (And some devices will lie, but at that point, oh well). You could do a test barrier IO at the start, and keep the old behavior if it fails, perhaps? (whoa, can barriers make something faster? who woulda thunk it) -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
