diff options
Diffstat (limited to 'Documentation/block/ublk.rst')
| -rw-r--r-- | Documentation/block/ublk.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/block/ublk.rst b/Documentation/block/ublk.rst index 2916fcf3ab44..1713b2890abb 100644 --- a/Documentation/block/ublk.rst +++ b/Documentation/block/ublk.rst @@ -154,7 +154,9 @@ managing and controlling ublk devices with help of several control commands: How to deal with userspace/kernel compatibility: 1) if kernel is capable of handling ``UBLK_F_UNPRIVILEGED_DEV`` + If ublk server supports ``UBLK_F_UNPRIVILEGED_DEV``: + ublk server should send ``UBLK_CMD_GET_DEV_INFO2``, given anytime unprivileged application needs to query devices the current user owns, when the application has no idea if ``UBLK_F_UNPRIVILEGED_DEV`` is set @@ -162,16 +164,20 @@ managing and controlling ublk devices with help of several control commands: retrieve it via ``UBLK_CMD_GET_DEV_INFO2`` If ublk server doesn't support ``UBLK_F_UNPRIVILEGED_DEV``: + ``UBLK_CMD_GET_DEV_INFO`` is always sent to kernel, and the feature of UBLK_F_UNPRIVILEGED_DEV isn't available for user 2) if kernel isn't capable of handling ``UBLK_F_UNPRIVILEGED_DEV`` + If ublk server supports ``UBLK_F_UNPRIVILEGED_DEV``: + ``UBLK_CMD_GET_DEV_INFO2`` is tried first, and will be failed, then ``UBLK_CMD_GET_DEV_INFO`` needs to be retried given ``UBLK_F_UNPRIVILEGED_DEV`` can't be set If ublk server doesn't support ``UBLK_F_UNPRIVILEGED_DEV``: + ``UBLK_CMD_GET_DEV_INFO`` is always sent to kernel, and the feature of ``UBLK_F_UNPRIVILEGED_DEV`` isn't available for user |