Hi, On Wed, Aug 10, 2011 at 02:10:22AM +0200, Samuel Thibault wrote:
> I've digged a bit in the libdiskfs syncing issue at shutdown. The > scenario is the following: > > - halt or reboot is issued > - S_startup_reboot() gets called in init which > - calls reboot_system(), which > - calls notify_shutdown(), which for each diskfs which registered itself > - calls startup_dosync() with a 1m grace period > - diskfs_S_startup_dosync() thus gets called in e.g. ext2fs, which > - syncs everything and marks hypermetadata as dirty > - inhibits RPCs > - syncs everything again and marks hypermetadata as clean > - resume RPCs > - init takes back hand, and eventually tells mach to hang or reboot. > > But since RPCs are resumed, processes can continue writing to files, > which makes ext2fs re-mark hypermetadata as dirty, and thus an > "unclean!" message from ext2fs at reboot. Nice catch! However, it explains only part of the problem: For me at least, once the startup_dosync went through, the "unclean" problem shows up only occasionally, and is generally harmless. The more serious issues happen when halt/reboot is issued during or shortly after disk activity (before the next regular sync), in which case the startup_dosync() doesn't work properly, and instead is forcefully aborted after the grace period (I presume)... -antrik-
