Commit e6f41633 authored by Jamie Pocas's avatar Jamie Pocas Committed by Nicholas Bellinger

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: default avatarJamie Pocas <jamie.pocas@emc.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent ef8f46b5
......@@ -499,6 +499,7 @@ DEF_CONFIGFS_ATTRIB_SHOW(max_unmap_lba_count);
DEF_CONFIGFS_ATTRIB_SHOW(max_unmap_block_desc_count);
DEF_CONFIGFS_ATTRIB_SHOW(unmap_granularity);
DEF_CONFIGFS_ATTRIB_SHOW(unmap_granularity_alignment);
DEF_CONFIGFS_ATTRIB_SHOW(unmap_zeroes_data);
DEF_CONFIGFS_ATTRIB_SHOW(max_write_same_len);
#define DEF_CONFIGFS_ATTRIB_STORE_U32(_name) \
......@@ -866,6 +867,39 @@ static ssize_t emulate_rest_reord_store(struct config_item *item,
return count;
}
static ssize_t unmap_zeroes_data_store(struct config_item *item,
const char *page, size_t count)
{
struct se_dev_attrib *da = to_attrib(item);
bool flag;
int ret;
ret = strtobool(page, &flag);
if (ret < 0)
return ret;
if (da->da_dev->export_count) {
pr_err("dev[%p]: Unable to change SE Device"
" unmap_zeroes_data while export_count is %d\n",
da->da_dev, da->da_dev->export_count);
return -EINVAL;
}
/*
* We expect this value to be non-zero when generic Block Layer
* Discard supported is detected iblock_configure_device().
*/
if (flag && !da->max_unmap_block_desc_count) {
pr_err("dev[%p]: Thin Provisioning LBPRZ will not be set"
" because max_unmap_block_desc_count is zero\n",
da->da_dev);
return -ENOSYS;
}
da->unmap_zeroes_data = flag;
pr_debug("dev[%p]: SE Device Thin Provisioning LBPRZ bit: %d\n",
da->da_dev, flag);
return 0;
}
/*
* Note, this can only be called on unexported SE Device Object.
*/
......@@ -998,6 +1032,7 @@ CONFIGFS_ATTR(, max_unmap_lba_count);
CONFIGFS_ATTR(, max_unmap_block_desc_count);
CONFIGFS_ATTR(, unmap_granularity);
CONFIGFS_ATTR(, unmap_granularity_alignment);
CONFIGFS_ATTR(, unmap_zeroes_data);
CONFIGFS_ATTR(, max_write_same_len);
/*
......@@ -1034,6 +1069,7 @@ struct configfs_attribute *sbc_attrib_attrs[] = {
&attr_max_unmap_block_desc_count,
&attr_unmap_granularity,
&attr_unmap_granularity_alignment,
&attr_unmap_zeroes_data,
&attr_max_write_same_len,
NULL,
};
......
......@@ -813,6 +813,8 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
dev->dev_attrib.unmap_granularity = DA_UNMAP_GRANULARITY_DEFAULT;
dev->dev_attrib.unmap_granularity_alignment =
DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT;
dev->dev_attrib.unmap_zeroes_data =
DA_UNMAP_ZEROES_DATA_DEFAULT;
dev->dev_attrib.max_write_same_len = DA_MAX_WRITE_SAME_LEN;
xcopy_lun = &dev->xcopy_lun;
......
......@@ -138,6 +138,8 @@ static int iblock_configure_device(struct se_device *dev)
q->limits.discard_granularity >> 9;
dev->dev_attrib.unmap_granularity_alignment =
q->limits.discard_alignment;
dev->dev_attrib.unmap_zeroes_data =
q->limits.discard_zeroes_data;
pr_debug("IBLOCK: BLOCK Discard support available,"
" disabled by default\n");
......
......@@ -141,9 +141,17 @@ sbc_emulate_readcapacity_16(struct se_cmd *cmd)
* Set Thin Provisioning Enable bit following sbc3r22 in section
* READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
*/
if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
buf[14] |= 0x80;
/*
* LBPRZ signifies that zeroes will be read back from an LBA after
* an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
*/
if (dev->dev_attrib.unmap_zeroes_data)
buf[14] |= 0x40;
}
rbuf = transport_kmap_data_sg(cmd);
if (rbuf) {
memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
......
......@@ -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;
}
......
......@@ -63,6 +63,8 @@
#define DA_UNMAP_GRANULARITY_DEFAULT 0
/* Default unmap_granularity_alignment */
#define DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT 0
/* Default unmap_zeroes_data */
#define DA_UNMAP_ZEROES_DATA_DEFAULT 0
/* Default max_write_same_len, disabled by default */
#define DA_MAX_WRITE_SAME_LEN 0
/* Use a model alias based on the configfs backend device name */
......@@ -674,6 +676,7 @@ struct se_dev_attrib {
int force_pr_aptpl;
int is_nonrot;
int emulate_rest_reord;
int unmap_zeroes_data;
u32 hw_block_size;
u32 block_size;
u32 hw_max_sectors;
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment