dm cache: add cache block invalidation support
Cache block invalidation is removing an entry from the cache without
writing it back. Cache blocks can be invalidated via the
'invalidate_cblocks' message, which takes an arbitrary number of cblock
ranges:
invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]*
E.g.
dmsetup message my_cache 0 invalidate_cblocks 2345 3456-4567 5678-6789
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt
index ff6639f..fc9d2df 100644
--- a/Documentation/device-mapper/cache.txt
+++ b/Documentation/device-mapper/cache.txt
@@ -244,12 +244,22 @@
E.g.
dmsetup message my_cache 0 sequential_threshold 1024
+
+Invalidation is removing an entry from the cache without writing it
+back. Cache blocks can be invalidated via the invalidate_cblocks
+message, which takes an arbitrary number of cblock ranges.
+
+ invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]*
+
+E.g.
+ dmsetup message my_cache 0 invalidate_cblocks 2345 3456-4567 5678-6789
+
Examples
========
The test suite can be found here:
-https://github.com/jthornber/thinp-test-suite
+https://github.com/jthornber/device-mapper-test-suite
dmsetup create my_cache --table '0 41943040 cache /dev/mapper/metadata \
/dev/mapper/ssd /dev/mapper/origin 512 1 writeback default 0'
