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>
This commit is contained in:
Joe Thornber 2012-03-28 18:41:24 +01:00 committed by Alasdair G Kergon
parent 035220b33d
commit fe878f34df
2 changed files with 1 additions and 11 deletions

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@ -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

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@ -72,7 +72,7 @@
* missed out if the io covers the block. (schedule_copy).
*
* iv) insert the new mapping into the origin's btree
* (process_prepared_mappings). This act of inserting breaks some
* (process_prepared_mapping). This act of inserting breaks some
* sharing of btree nodes between the two devices. Breaking sharing only
* effects the btree of that specific device. Btrees for the other
* devices that share the block never change. The btree for the origin