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Commit 5de619a3 authored by Nicholas Bellinger's avatar Nicholas Bellinger
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target: Update QUEUE ALGORITHM MODIFIER control page default 



This patch adds the default 'Unrestricted reordering allowed' for SCSI
control mode page QUEUE ALGORITHM MODIFIER on a per se_device basis in
target_modesense_control() following spc4r23.  This includes a new
emuluate_rest_reord configfs attribute that currently (only) accepts
zero to signal 'Unrestricted reordering allowed' in control mode page
usage by the backend target device.

Reported-by: default avatarRoland Dreier <roland@purestorage.com>
Signed-off-by: default avatarNicholas Bellinger <nab@risingtidesystems.com>
parent 1d20bb61

drivers/target/target_core_cdb.c

+29 −0
Original line number Diff line number Diff line
@@ -774,6 +774,35 @@ target_modesense_control(struct se_device *dev, unsigned char *p) 
	p[0] = 0x0a;

	p[1] = 0x0a;

	p[2] = 2;

	/*

	 * From spc4r23, 7.4.7 Control mode page

	 *

	 * The QUEUE ALGORITHM MODIFIER field (see table 368) specifies

	 * restrictions on the algorithm used for reordering commands

	 * having the SIMPLE task attribute (see SAM-4).

	 *

	 *                    Table 368 -- QUEUE ALGORITHM MODIFIER field

	 *                         Code      Description

	 *                          0h       Restricted reordering

	 *                          1h       Unrestricted reordering allowed

	 *                          2h to 7h    Reserved

	 *                          8h to Fh    Vendor specific

	 *

	 * A value of zero in the QUEUE ALGORITHM MODIFIER field specifies that

	 * the device server shall order the processing sequence of commands

	 * having the SIMPLE task attribute such that data integrity is maintained

	 * for that I_T nexus (i.e., if the transmission of new SCSI transport protocol

	 * requests is halted at any time, the final value of all data observable

	 * on the medium shall be the same as if all the commands had been processed

	 * with the ORDERED task attribute).

	 *

	 * A value of one in the QUEUE ALGORITHM MODIFIER field specifies that the

	 * device server may reorder the processing sequence of commands having the

	 * SIMPLE task attribute in any manner. Any data integrity exposures related to

	 * command sequence order shall be explicitly handled by the application client

	 * through the selection of appropriate ommands and task attributes.

	 */

	p[3] = (dev->se_sub_dev->se_dev_attrib.emulate_rest_reord == 1) ? 0x00 : 0x10;

	/*

	 * From spc4r17, section 7.4.6 Control mode Page

	 *

drivers/target/target_core_configfs.c

+4 −0
Original line number Diff line number Diff line
@@ -701,6 +701,9 @@ SE_DEV_ATTR(enforce_pr_isids, S_IRUGO | S_IWUSR); 
DEF_DEV_ATTRIB(is_nonrot);

SE_DEV_ATTR(is_nonrot, S_IRUGO | S_IWUSR);



DEF_DEV_ATTRIB(emulate_rest_reord);

SE_DEV_ATTR(emulate_rest_reord, S_IRUGO | S_IWUSR);



DEF_DEV_ATTRIB_RO(hw_block_size);

SE_DEV_ATTR_RO(hw_block_size);
@@ -750,6 +753,7 @@ static struct configfs_attribute *target_core_dev_attrib_attrs[] = { 
	&target_core_dev_attrib_emulate_tpws.attr,

	&target_core_dev_attrib_enforce_pr_isids.attr,

	&target_core_dev_attrib_is_nonrot.attr,

	&target_core_dev_attrib_emulate_rest_reord.attr,

	&target_core_dev_attrib_hw_block_size.attr,

	&target_core_dev_attrib_block_size.attr,

	&target_core_dev_attrib_hw_max_sectors.attr,

drivers/target/target_core_device.c

+14 −1
Original line number Diff line number Diff line
@@ -857,6 +857,7 @@ void se_dev_set_default_attribs( 
	dev->se_sub_dev->se_dev_attrib.emulate_alua = DA_EMULATE_ALUA;

	dev->se_sub_dev->se_dev_attrib.enforce_pr_isids = DA_ENFORCE_PR_ISIDS;

	dev->se_sub_dev->se_dev_attrib.is_nonrot = DA_IS_NONROT;

	dev->se_sub_dev->se_dev_attrib.emulate_rest_reord = DA_EMULATE_REST_REORD;

	/*

	 * The TPU=1 and TPWS=1 settings will be set in TCM/IBLOCK

	 * iblock_create_virtdevice() from struct queue_limits values
@@ -1128,11 +1129,23 @@ int se_dev_set_is_nonrot(struct se_device *dev, int flag) 
		return -EINVAL;

	}

	dev->se_sub_dev->se_dev_attrib.is_nonrot = flag;

	printk(KERN_INFO "dev[%p]: SE Device is_nonrot bit: %d\n",

	pr_debug("dev[%p]: SE Device is_nonrot bit: %d\n",

	       dev, flag);

	return 0;

}



int se_dev_set_emulate_rest_reord(struct se_device *dev, int flag)

{

	if (flag != 0) {

		printk(KERN_ERR "dev[%p]: SE Device emulatation of restricted"

			" reordering not implemented\n", dev);

		return -ENOSYS;

	}

	dev->se_sub_dev->se_dev_attrib.emulate_rest_reord = flag;

	pr_debug("dev[%p]: SE Device emulate_rest_reord: %d\n", dev, flag);

	return 0;

}



/*

 * Note, this can only be called on unexported SE Device Object.

 */

include/target/target_core_base.h

+1 −0
Original line number Diff line number Diff line
@@ -662,6 +662,7 @@ struct se_dev_attrib { 
	int		emulate_alua;

	int		enforce_pr_isids;

	int		is_nonrot;

	int		emulate_rest_reord;

	u32		hw_block_size;

	u32		block_size;

	u32		hw_max_sectors;

include/target/target_core_device.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ extern int se_dev_set_emulate_tpu(struct se_device *, int); 
extern int se_dev_set_emulate_tpws(struct se_device *, int);

extern int se_dev_set_enforce_pr_isids(struct se_device *, int);

extern int se_dev_set_is_nonrot(struct se_device *, int);

extern int se_dev_set_emulate_rest_reord(struct se_device *dev, int);

extern int se_dev_set_queue_depth(struct se_device *, u32);

extern int se_dev_set_max_sectors(struct se_device *, u32);

extern int se_dev_set_optimal_sectors(struct se_device *, u32);