Commit a119799b ("test/nvme/aer: remove duplicated changed NS list log")
changed the nvme driver to read the CHANGED_NS_LIST log page before
calling the application's AER callback (previously it would read it
after).
Commit b801af090 ("nvme: add disable_read_changed_ns_list_log_page")
added a new ctrlr_opts member to allow the application to tell the
driver to not read this log page, and will read the log page itself
instead to clear the AEN. But we cannot add this option to the 22.01
LTS branch since it breaks the ABI. So adding this API here, which
can then be backported manually to the 22.01 branch for LTS users
that require it.
Restoring the old behavior is not correct for applications that
want to consume the CHANGED_NS_LIST log page contents itself to
know which namespaces have changed. Even if the driver reads the
log page after the application, that read could happen during a
small window between when a namespace change event has occurred and
the AEN has been sent to the host. The only safe way for the
application to consume ChANGED_NS_LIST log page contents itself
is to make sure the driver never issues such a log page request
itself.
Fixes issue #2647.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: Iaeffe23dc7817c0c94441a36ed4d6f64a1f15a4e
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/14134
Reviewed-by: Michael Haeuptle <michaelhaeuptle@gmail.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Dong Yi <dongx.yi@intel.com>
Reviewed-by: Shuhei Matsumoto <smatsumoto@nvidia.com>
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>