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Commit 773cbaf7 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Add/check max_write_same_len device attribute + update block limits VPD 



This patch adds a new max_write_same_len device attribute for use with
WRITE_SAME w/ UNMAP=0 backend emulation.  This can be useful for
lowering the default backend value (IBLOCK uses 0xFFFF).

Also, update block limits VPD emulation code in spc_emulate_evpd_b0() to
report MAXIMUM WRITE SAME LENGTH, and enforce max_write_same_len during
sbc_parse() -> sbc_setup_write_same() CDB sanity checking for all emulated
WRITE_SAME w/ UNMAP=0 cases.

(Robert: Move max_write_same_len check in sbc_setup_write_same() to
         check both WRITE_SAME w/ UNMAP=1 and w/ UNMAP=0 cases)

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent cd063bef

drivers/target/target_core_configfs.c

+4 −0
Original line number Diff line number Diff line
@@ -676,6 +676,9 @@ SE_DEV_ATTR(unmap_granularity, S_IRUGO | S_IWUSR); 
DEF_DEV_ATTRIB(unmap_granularity_alignment);

SE_DEV_ATTR(unmap_granularity_alignment, S_IRUGO | S_IWUSR);



DEF_DEV_ATTRIB(max_write_same_len);

SE_DEV_ATTR(max_write_same_len, S_IRUGO | S_IWUSR);



CONFIGFS_EATTR_OPS(target_core_dev_attrib, se_dev_attrib, da_group);



static struct configfs_attribute *target_core_dev_attrib_attrs[] = {
@@ -701,6 +704,7 @@ static struct configfs_attribute *target_core_dev_attrib_attrs[] = { 
	&target_core_dev_attrib_max_unmap_block_desc_count.attr,

	&target_core_dev_attrib_unmap_granularity.attr,

	&target_core_dev_attrib_unmap_granularity_alignment.attr,

	&target_core_dev_attrib_max_write_same_len.attr,

	NULL,

};

drivers/target/target_core_device.c

+11 −0
Original line number Diff line number Diff line
@@ -706,6 +706,16 @@ int se_dev_set_unmap_granularity_alignment( 
	return 0;

}



int se_dev_set_max_write_same_len(

	struct se_device *dev,

	u32 max_write_same_len)

{

	dev->dev_attrib.max_write_same_len = max_write_same_len;

	pr_debug("dev[%p]: Set max_write_same_len: %u\n",

			dev, dev->dev_attrib.max_write_same_len);

	return 0;

}



int se_dev_set_emulate_dpo(struct se_device *dev, int flag)

{

	if (flag != 0 && flag != 1) {
@@ -1393,6 +1403,7 @@ 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.max_write_same_len = DA_MAX_WRITE_SAME_LEN;

	dev->dev_attrib.fabric_max_sectors = DA_FABRIC_MAX_SECTORS;

	dev->dev_attrib.optimal_sectors = DA_FABRIC_MAX_SECTORS;

drivers/target/target_core_internal.h

+1 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ int se_dev_set_max_unmap_lba_count(struct se_device *, u32); 
int	se_dev_set_max_unmap_block_desc_count(struct se_device *, u32);

int	se_dev_set_unmap_granularity(struct se_device *, u32);

int	se_dev_set_unmap_granularity_alignment(struct se_device *, u32);

int	se_dev_set_max_write_same_len(struct se_device *, u32);

int	se_dev_set_emulate_dpo(struct se_device *, int);

int	se_dev_set_emulate_fua_write(struct se_device *, int);

int	se_dev_set_emulate_fua_read(struct se_device *, int);

drivers/target/target_core_sbc.c

+7 −0
Original line number Diff line number Diff line
@@ -238,12 +238,19 @@ static inline unsigned long long transport_lba_64_ext(unsigned char *cdb) 
static sense_reason_t

sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)

{

	unsigned int sectors = spc_get_write_same_sectors(cmd);



	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {

		pr_err("WRITE_SAME PBDATA and LBDATA"

			" bits not supported for Block Discard"

			" Emulation\n");

		return TCM_UNSUPPORTED_SCSI_OPCODE;

	}

	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {

		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",

			sectors, cmd->se_dev->dev_attrib.max_write_same_len);

		return TCM_INVALID_CDB_FIELD;

	}

	/*

	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting

	 * translated into block discard requests within backend code.

drivers/target/target_core_spc.c

+7 −1
Original line number Diff line number Diff line
@@ -465,7 +465,7 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) 
	 * Exit now if we don't support TP.

	 */

	if (!have_tp)

		return 0;

		goto max_write_same;



	/*

	 * Set MAXIMUM UNMAP LBA COUNT
@@ -491,6 +491,12 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) 
	if (dev->dev_attrib.unmap_granularity_alignment != 0)

		buf[32] |= 0x80; /* Set the UGAVALID bit */



	/*

	 * MAXIMUM WRITE SAME LENGTH

	 */

max_write_same:

	put_unaligned_be64(dev->dev_attrib.max_write_same_len, &buf[36]);



	return 0;

}