Hello, On Mon 27-05-13 09:54:13, Bert De Jonghe wrote: > On an otherwise idle system, create an ext4 filesystem on /dev/sdi, > mount it and wait more than dirty_writeback_centisecs. What kernel version are you using? > Then create a small file (echo something > file); wait > (dirty_expire_centisecs x 2), expect delayed_allocation_blocks to > fall to zero but it remains at 2 over here. > > Create another small file (echo something_else > file2); again wait > (dirty_expire_centisecs x 2); check delayed_allocation_blocks which > is now at 4. > > Wait a weekend more: > > # date; cat /sys/fs/ext4/sdi/delayed_allocation_blocks > Fri May 24 15:33:21 UTC 2013 > 4 > > # date; cat /sys/fs/ext4/sdi/delayed_allocation_blocks > Mon May 27 07:14:30 UTC 2013 > 4 > > Doing a manual sync flushes out all blocks, also adding a sync after > mounting solves the not flushing behaviour (possible patch > attached). > > Has anyone noticed this before and is this expected behaviour? It > looks like these blocks are not flushed out to disk thus remain in > memory and will be lost upon power failure? This would be a bug. I have tried to recreate this with my 3.7.10 kernel but I failed. File gets flushed to disk after 30s or so. What kernel version are you using? Also I don't see why syncing after mount would help to resolve the problem that files are not flushed to disk in a timely manner... Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- 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
