tree 727b6dc7596b8250d644214695f09e3d6c7e43d1
parent 327372797c88b24953f454cd51a3734c02697bdd
author Milan Broz <mbroz@redhat.com> 1312284728 +0100
committer Alasdair G Kergon <agk@redhat.com> 1312284728 +0100

dm crypt: optionally support discard requests

Add optional parameter field to dmcrypt table and support
"allow_discards" option.

Discard requests bypass crypt queue processing. Bio is simple remapped
to underlying device.

Note that discard will be never enabled by default because of security
consequences.  It is up to the administrator to enable it for encrypted
devices.

(Note that userspace cryptsetup does not understand new optional
parameters yet.  Support for this will come later.  Until then, you
should use 'dmsetup' to enable and disable this.)

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>