dm cache: update Documentation for invalidate_cblocks's range syntax

The cache target's invalidate_cblocks message allows cache block
(cblock) ranges to be expressed with: <cblock start>-<cblock end>

The range's <cblock end> value is "one past the end", so the range
includes <cblock start> through <cblock end>-1.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
This commit is contained in:
Mike Snitzer 2013-11-26 11:03:54 -05:00
parent af95e7a69b
commit 83f539e1a4

View file

@ -266,10 +266,12 @@ E.g.
Invalidation is removing an entry from the cache without writing it Invalidation is removing an entry from the cache without writing it
back. Cache blocks can be invalidated via the invalidate_cblocks back. Cache blocks can be invalidated via the invalidate_cblocks
message, which takes an arbitrary number of cblock ranges. Each cblock message, which takes an arbitrary number of cblock ranges. Each cblock
must be expressed as a decimal value, in the future a variant message range's end value is "one past the end", meaning 5-10 expresses a range
that takes cblock ranges expressed in hexidecimal may be needed to of values from 5 to 9. Each cblock must be expressed as a decimal
better support efficient invalidation of larger caches. The cache must value, in the future a variant message that takes cblock ranges
be in passthrough mode when invalidate_cblocks is used. expressed in hexidecimal may be needed to better support efficient
invalidation of larger caches. The cache must be in passthrough mode
when invalidate_cblocks is used.
invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]* invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]*