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Commit 7f7caf6a authored by Andy Grover's avatar Andy Grover Committed by Nicholas Bellinger
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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: default avatarAndy Grover <agrover@redhat.com>
Acked-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent f01b9f73

drivers/target/target_core_iblock.c

+43 −0
Original line number Original line Diff line number Diff line
@@ -710,6 +710,45 @@ static sector_t iblock_get_blocks(struct se_device *dev) 
	return iblock_emulate_read_cap_with_block_size(dev, bd, q);

	return iblock_emulate_read_cap_with_block_size(dev, bd, q);

}

}





static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)

{

	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);

	struct block_device *bd = ib_dev->ibd_bd;

	int ret;



	ret = bdev_alignment_offset(bd);

	if (ret == -1)

		return 0;



	/* convert offset-bytes to offset-lbas */

	return ret / bdev_logical_block_size(bd);

}



static unsigned int iblock_get_lbppbe(struct se_device *dev)

{

	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);

	struct block_device *bd = ib_dev->ibd_bd;

	int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);



	return ilog2(logs_per_phys);

}



static unsigned int iblock_get_io_min(struct se_device *dev)

{

	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);

	struct block_device *bd = ib_dev->ibd_bd;



	return bdev_io_min(bd);

}



static unsigned int iblock_get_io_opt(struct se_device *dev)

{

	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);

	struct block_device *bd = ib_dev->ibd_bd;



	return bdev_io_opt(bd);

}



static struct sbc_ops iblock_sbc_ops = {

static struct sbc_ops iblock_sbc_ops = {

	.execute_rw		= iblock_execute_rw,

	.execute_rw		= iblock_execute_rw,

	.execute_sync_cache	= iblock_execute_sync_cache,

	.execute_sync_cache	= iblock_execute_sync_cache,
@@ -749,6 +788,10 @@ static struct se_subsystem_api iblock_template = { 
	.show_configfs_dev_params = iblock_show_configfs_dev_params,

	.show_configfs_dev_params = iblock_show_configfs_dev_params,

	.get_device_type	= sbc_get_device_type,

	.get_device_type	= sbc_get_device_type,

	.get_blocks		= iblock_get_blocks,

	.get_blocks		= iblock_get_blocks,

	.get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,

	.get_lbppbe		= iblock_get_lbppbe,

	.get_io_min		= iblock_get_io_min,

	.get_io_opt		= iblock_get_io_opt,

	.get_write_cache	= iblock_get_write_cache,

	.get_write_cache	= iblock_get_write_cache,

};

};

drivers/target/target_core_sbc.c

+11 −1
Original line number Original line Diff line number Diff line
@@ -105,12 +105,22 @@ sbc_emulate_readcapacity_16(struct se_cmd *cmd) 
	buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;

	buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;

	buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;

	buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;

	buf[11] = dev->dev_attrib.block_size & 0xff;

	buf[11] = dev->dev_attrib.block_size & 0xff;



	if (dev->transport->get_lbppbe)

		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;



	if (dev->transport->get_alignment_offset_lbas) {

		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);

		buf[14] = (lalba >> 8) & 0x3f;

		buf[15] = lalba & 0xff;

	}



	/*

	/*

	 * Set Thin Provisioning Enable bit following sbc3r22 in section

	 * Set Thin Provisioning Enable bit following sbc3r22 in section

	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.

	 * 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;

		buf[14] |= 0x80;





	rbuf = transport_kmap_data_sg(cmd);

	rbuf = transport_kmap_data_sg(cmd);

	if (rbuf) {

	if (rbuf) {

drivers/target/target_core_spc.c

+9 −2
Original line number Original line Diff line number Diff line
@@ -452,6 +452,7 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) 
	struct se_device *dev = cmd->se_dev;

	struct se_device *dev = cmd->se_dev;

	u32 max_sectors;

	u32 max_sectors;

	int have_tp = 0;

	int have_tp = 0;

	int opt, min;





	/*

	/*

	 * Following spc3r22 section 6.5.3 Block Limits VPD page, when

	 * Following spc3r22 section 6.5.3 Block Limits VPD page, when
@@ -475,6 +476,9 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) 
	/*

	/*

	 * Set OPTIMAL TRANSFER LENGTH GRANULARITY

	 * Set OPTIMAL TRANSFER LENGTH GRANULARITY

	 */

	 */

	if (dev->transport->get_io_min && (min = dev->transport->get_io_min(dev)))

		put_unaligned_be16(min / dev->dev_attrib.block_size, &buf[6]);

	else

		put_unaligned_be16(1, &buf[6]);

		put_unaligned_be16(1, &buf[6]);





	/*

	/*
@@ -487,6 +491,9 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) 
	/*

	/*

	 * Set OPTIMAL TRANSFER LENGTH

	 * Set OPTIMAL TRANSFER LENGTH

	 */

	 */

	if (dev->transport->get_io_opt && (opt = dev->transport->get_io_opt(dev)))

		put_unaligned_be32(opt / dev->dev_attrib.block_size, &buf[12]);

	else

		put_unaligned_be32(dev->dev_attrib.optimal_sectors, &buf[12]);

		put_unaligned_be32(dev->dev_attrib.optimal_sectors, &buf[12]);





	/*

	/*

include/target/target_core_backend.h

+5 −0
Original line number Original line Diff line number Diff line
@@ -34,6 +34,11 @@ struct se_subsystem_api { 
	sense_reason_t (*parse_cdb)(struct se_cmd *cmd);

	sense_reason_t (*parse_cdb)(struct se_cmd *cmd);

	u32 (*get_device_type)(struct se_device *);

	u32 (*get_device_type)(struct se_device *);

	sector_t (*get_blocks)(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 *);

	unsigned char *(*get_sense_buffer)(struct se_cmd *);

	bool (*get_write_cache)(struct se_device *);

	bool (*get_write_cache)(struct se_device *);

};

};