diff options
| author | Jamie Pocas <jamie.pocas@emc.com> | 2015-11-29 14:44:57 -0800 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2016-01-06 13:39:55 -0800 |
| commit | e6f41633cb79b55ead84b023c02035322c7827e7 (patch) | |
| tree | 342f55892f82d100f496c8ed73f3570c8d956842 /drivers/target/target_core_spc.c | |
| parent | ef8f46b549c2e425513ed568f18c827a37c08727 (diff) | |
target/sbc: Add LBPRZ attribute + control CDB emulation
This change sets the LBPRZ flag in EVPD page b2h and READ CAPACITY (16)
based on a new unmap_zeroes_data device attribute. This flag is set
automatically for iblock based on underlying block device queue's
discard_zeroes_data flag.
Signed-off-by: Jamie Pocas <jamie.pocas@emc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_spc.c')
| -rw-r--r-- | drivers/target/target_core_spc.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index 9413e1a949e5..0aa47babd16c 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -635,6 +635,18 @@ spc_emulate_evpd_b2(struct se_cmd *cmd, unsigned char *buf) if (dev->dev_attrib.emulate_tpws != 0) buf[5] |= 0x40 | 0x20; + /* + * The unmap_zeroes_data set means that the underlying device supports + * REQ_DISCARD and has the discard_zeroes_data bit set. This satisfies + * the SBC requirements for LBPRZ, meaning that a subsequent read + * will return zeroes after an UNMAP or WRITE SAME (16) to an LBA + * See sbc4r36 6.6.4. + */ + if (((dev->dev_attrib.emulate_tpu != 0) || + (dev->dev_attrib.emulate_tpws != 0)) && + (dev->dev_attrib.unmap_zeroes_data != 0)) + buf[5] |= 0x04; + return 0; } |