X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=Documentation%2Fblock%2Fbarrier.txt;h=a272c3db80940bd5821e8b2f28068e3fe5d5a65b;hb=refs%2Fheads%2Fvserver;hp=03971518b22254781bce94bea5c749f0a2cd1e7f;hpb=16cf0ec7408f389279d413869e94c1a351392f97;p=linux-2.6.git diff --git a/Documentation/block/barrier.txt b/Documentation/block/barrier.txt index 03971518b..a272c3db8 100644 --- a/Documentation/block/barrier.txt +++ b/Documentation/block/barrier.txt @@ -25,7 +25,7 @@ of the following three ways. i. For devices which have queue depth greater than 1 (TCQ devices) and support ordered tags, block layer can just issue the barrier as an ordered request and the lower level driver, controller and drive -itself are responsible for making sure that the ordering contraint is +itself are responsible for making sure that the ordering constraint is met. Most modern SCSI controllers/drives should support this. NOTE: SCSI ordered tag isn't currently used due to limitation in the @@ -42,7 +42,7 @@ iii. Devices which have queue depth of 1. This is a degenerate case of ii. Just keeping issue order suffices. Ancient SCSI controllers/drives and IDE drives are in this category. -2. Forced flushing to physcial medium +2. Forced flushing to physical medium Again, if you're not gonna do synchronization with disk drives (dang, it sounds even more appealing now!), the reason you use I/O barriers @@ -56,7 +56,7 @@ There are four cases, i. No write-back cache. Keeping requests ordered is enough. ii. Write-back cache but no flush operation. There's no way to -gurantee physical-medium commit order. This kind of devices can't to +guarantee physical-medium commit order. This kind of devices can't to I/O barriers. iii. Write-back cache and flush operation but no FUA (forced unit