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Commit fe878f34 authored Mar 28, 2012 by Joe Thornber Committed by Alasdair G Kergon Mar 28, 2012

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>

parent 035220b3

Documentation/device-mapper/thin-provisioning.txt

+0 −10

Original line number	Diff line number	Diff line
		@@ -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

drivers/md/dm-thin.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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