diff options
Diffstat (limited to 'Documentation/block/barrier.txt')
-rw-r--r-- | Documentation/block/barrier.txt | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/Documentation/block/barrier.txt b/Documentation/block/barrier.txt index 03971518b222..a272c3db8094 100644 --- a/Documentation/block/barrier.txt +++ b/Documentation/block/barrier.txt | |||
@@ -25,7 +25,7 @@ of the following three ways. | |||
25 | i. For devices which have queue depth greater than 1 (TCQ devices) and | 25 | i. For devices which have queue depth greater than 1 (TCQ devices) and |
26 | support ordered tags, block layer can just issue the barrier as an | 26 | support ordered tags, block layer can just issue the barrier as an |
27 | ordered request and the lower level driver, controller and drive | 27 | ordered request and the lower level driver, controller and drive |
28 | itself are responsible for making sure that the ordering contraint is | 28 | itself are responsible for making sure that the ordering constraint is |
29 | met. Most modern SCSI controllers/drives should support this. | 29 | met. Most modern SCSI controllers/drives should support this. |
30 | 30 | ||
31 | NOTE: SCSI ordered tag isn't currently used due to limitation in the | 31 | 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 | |||
42 | of ii. Just keeping issue order suffices. Ancient SCSI | 42 | of ii. Just keeping issue order suffices. Ancient SCSI |
43 | controllers/drives and IDE drives are in this category. | 43 | controllers/drives and IDE drives are in this category. |
44 | 44 | ||
45 | 2. Forced flushing to physcial medium | 45 | 2. Forced flushing to physical medium |
46 | 46 | ||
47 | Again, if you're not gonna do synchronization with disk drives (dang, | 47 | Again, if you're not gonna do synchronization with disk drives (dang, |
48 | it sounds even more appealing now!), the reason you use I/O barriers | 48 | it sounds even more appealing now!), the reason you use I/O barriers |
@@ -56,7 +56,7 @@ There are four cases, | |||
56 | i. No write-back cache. Keeping requests ordered is enough. | 56 | i. No write-back cache. Keeping requests ordered is enough. |
57 | 57 | ||
58 | ii. Write-back cache but no flush operation. There's no way to | 58 | ii. Write-back cache but no flush operation. There's no way to |
59 | gurantee physical-medium commit order. This kind of devices can't to | 59 | guarantee physical-medium commit order. This kind of devices can't to |
60 | I/O barriers. | 60 | I/O barriers. |
61 | 61 | ||
62 | iii. Write-back cache and flush operation but no FUA (forced unit | 62 | iii. Write-back cache and flush operation but no FUA (forced unit |