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authorAndy Grover <agrover@redhat.com>2013-11-11 08:59:17 -0800
committerNicholas Bellinger <nab@linux-iscsi.org>2013-11-12 13:44:54 -0800
commit7f7caf6aa74a4f4ad21ebe08bf23b594fce45ca7 (patch)
tree058c55e859712486b9f6a8a20f3ea46add3a30eb /include/target/target_core_backend.h
parentf01b9f73392b48c6cda7c2c66594c73137c776da (diff)
target: Pass through I/O topology for block backstores
In addition to block size (already implemented), passing through alignment offset, logical-to-phys block exponent, I/O granularity and optimal I/O length will allow initiators to properly handle layout on LUNs with 4K block sizes. Tested with various weird values via scsi_debug module. One thing to look at with this patch is the new block limits values -- instead of granularity 1 optimal 8192, Lio will now be returning whatever the block device says, which may affect performance. Signed-off-by: Andy Grover <agrover@redhat.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/target/target_core_backend.h')
-rw-r--r--include/target/target_core_backend.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 5ebe21cd5d1c..39e0114d70c5 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -34,6 +34,11 @@ struct se_subsystem_api {
sense_reason_t (*parse_cdb)(struct se_cmd *cmd);
u32 (*get_device_type)(struct se_device *);
sector_t (*get_blocks)(struct se_device *);
+ sector_t (*get_alignment_offset_lbas)(struct se_device *);
+ /* lbppbe = logical blocks per physical block exponent. see SBC-3 */
+ unsigned int (*get_lbppbe)(struct se_device *);
+ unsigned int (*get_io_min)(struct se_device *);
+ unsigned int (*get_io_opt)(struct se_device *);
unsigned char *(*get_sense_buffer)(struct se_cmd *);
bool (*get_write_cache)(struct se_device *);
};