target: Implement Block Device Characteristics VPD page

Implement page B1h, Block Device Characteristics, so that we can report
a medium rotation rate of 1 (non-rotating / solid state) if the
is_nonrot device attribute is set; we update the iblock backend to set
this attribute if the underlying Linux block device has its nonrot
flag set.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 4 insertions, 0 deletions

diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index cd163dd94cd4..81deb399bf6a 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -661,6 +661,7 @@ struct se_dev_attrib {
         int             emulate_reservations;
         int             emulate_alua;
         int             enforce_pr_isids;
+        int             is_nonrot;
         u32             hw_block_size;
         u32             block_size;
         u32             hw_max_sectors;
diff --git a/include/target/target_core_device.h b/include/target/target_core_device.h
index 96586cc94984..f3b6ae655454 100644
--- a/include/target/target_core_device.h
+++ b/include/target/target_core_device.h
@@ -39,6 +39,7 @@ extern int se_dev_set_emulate_tas(struct se_device *, int);
 extern int se_dev_set_emulate_tpu(struct se_device *, int);
 extern int se_dev_set_emulate_tpws(struct se_device *, int);
 extern int se_dev_set_enforce_pr_isids(struct se_device *, int);
+extern int se_dev_set_is_nonrot(struct se_device *, int);
 extern int se_dev_set_queue_depth(struct se_device *, u32);
 extern int se_dev_set_max_sectors(struct se_device *, u32);
 extern int se_dev_set_optimal_sectors(struct se_device *, u32);
diff --git a/include/target/target_core_transport.h b/include/target/target_core_transport.h
index 2aae76412377..b27ce1af698b 100644
--- a/include/target/target_core_transport.h
+++ b/include/target/target_core_transport.h
@@ -101,6 +101,8 @@
 #define DA_ENFORCE_PR_ISIDS                     1
 #define DA_STATUS_MAX_SECTORS_MIN               16
 #define DA_STATUS_MAX_SECTORS_MAX               8192
+/* By default don't report non-rotating (solid state) medium */
+#define DA_IS_NONROT                            0
 
 #define SE_MODE_PAGE_BUF                        512