On Fri, Jul 01, 2011 at 03:55:33PM -0700, Curt Wohlgemuth wrote: > One other issue I have with sync as it's structured is that we don't > do a WB_SYNC_ALL pass on any inode that's only associated with a block > device, and not on a mounted filesystem. Blockdev mounts are > pseudo-mounts, and are explicitly skipped in __sync_filesystem(). So > if you've written directly to a block device and do a sync, the only > pass over the pages for this inode are via the > wakeup_flusher_threads() -- which operates on a BDI, regardless of the > superblock, and uses WB_SYNC_NONE. > > All the sync_filesystem() calls are per-sb, not per-BDI, and they'll > exclude pseudo-superblocks. Interesting. I think that's actually correct by the traditional defintion of sync, but not really useful. I also doubt it's intentional. > I've seen cases in our modified kernels here at Google in which > lilo/shutdown failed because of a lack of WB_SYNC_ALL writeback for > /dev/sda (though I haven't been able to come up with a consistent test > case, nor reproduce this on an upstream kernel). lilo really should do an fsync of the partition it installed itself into. That's won't only fix this issue, but also has a lot less impact on the rest of the system. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
