target: Propigate backend read-only to core_tpg_add_lun

This patch adds a DF_READ_ONLY flag that is used by IBLOCK to
signal when a backend has been set to read-only mode, in order
to propigate read-only status up to core_tpg_add_lun() for all
future LUN fabric exports.

With this is place, existing emulation for reporting read-only
in spc_emulate_modesense() and normal transport_lookup_cmd_lun()
TCM_WRITE_PROTECTED status checking just works as expected.

Reported-by: Joeue Deng <joeue404@gmail.com>
Reported-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 5a9982f..0f19e11 100644 (file)
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -105,6 +105,8 @@ static int iblock_configure_device(struct se_device *dev)
        mode = FMODE_READ|FMODE_EXCL;
        if (!ib_dev->ibd_readonly)
                mode |= FMODE_WRITE;
+       else
+               dev->dev_flags |= DF_READ_ONLY;
 
        bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
        if (IS_ERR(bd)) {

diff --cc drivers/target/target_core_tpg.c
Simple merge

diff --cc include/target/target_core_base.h
Simple merge