only allow unprivileged passthrough for commands without effects

[Christoph Hellwig]

Hi all,

this series first fixes a few minor issues in the CES log support in the
host and target drivers and then uses the log to deny unprivileged
passthrough of commands that have effects, where the only practically
relevant effect is the modification of contents of the data stored in the
namespace.

Diffstat:
 host/core.c        |   47 ++++++++++++++++++++++++++---------------------
 host/ioctl.c       |   19 ++++++++++---------
 host/nvme.h        |    3 ++-
 target/admin-cmd.c |   37 +++++++++++++++++++++----------------
 target/passthru.c  |   25 +++++++++++++------------
 5 files changed, 72 insertions(+), 59 deletions(-)