dm thin: correct comments

Remove documentation for unimplemented 'trim' message.

I'd planned a 'trim' target message for shrinking thin devices, but
this is better handled via the discard ioctl.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 0 insertions, 10 deletions

diff --git a/Documentation/device-mapper/thin-provisioning.txt b/Documentation/device-mapper/thin-provisioning.txt
index 1ff044d87ca4..da50347c0053 100644
--- a/Documentation/device-mapper/thin-provisioning.txt
+++ b/Documentation/device-mapper/thin-provisioning.txt
@@ -237,16 +237,6 @@ iii) Messages
 
         Deletes a thin device.  Irreversible.
 
-    trim <dev id> <new size in sectors>
-
-        Delete mappings from the end of a thin device.  Irreversible.
-        You might want to use this if you're reducing the size of
-        your thinly-provisioned device.  In many cases, due to the
-        sharing of blocks between devices, it is not possible to
-        determine in advance how much space 'trim' will release.  (In
-        future a userspace tool might be able to perform this
-        calculation.)
-
     set_transaction_id <current id> <new id>
 
         Userland volume managers, such as LVM, need a way to