On Mon, Aug 24, 2009 at 06:07:39PM -0400, Theodore Tso wrote: > Sure, agreed. But let's look a bit closer at what "async commit" > really means. > > What ext3 and ext4 does by default is this: > > 1) Write data blocks required by data=ordered mode (if any) Shouldn't there be a write barrier after data blocks, so that the journal blocks aren't written first? ie, mark the first journal block write with barrier flag on. > 2) Write the journal blocks > > 3) Wait for the journal blocks to be sent to disk. (We don't actually > do a barrier operation), so this just means the blocks have been sent > to the disk, not necessarily that they are forced to a platter. > > 4) Write the commit block, with the barrier flag set. > > 5) Wait for the commit block. -- Tom Vier <nester@xxxxxxxxx> DSA Key ID 0x15741ECE -- 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
