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target: Update QUEUE ALGORITHM MODIFIER control page default

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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: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>
This commit is contained in:
Nicholas Bellinger 2011-07-17 02:57:58 -07:00
parent 1d20bb6147
commit 5de619a31d
6 changed files with 51 additions and 1 deletions
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29
drivers/target/target_core_cdb.c
View File

@ -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
*

4
drivers/target/target_core_configfs.c
View File

@ -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,

15
drivers/target/target_core_device.c
View File

@ -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.
*/

1
include/target/target_core_base.h
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@ -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;

1
include/target/target_core_device.h
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@ -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);

2
include/target/target_core_transport.h
View File

@ -103,6 +103,8 @@
#define DA_STATUS_MAX_SECTORS_MAX 8192
/* By default don't report non-rotating (solid state) medium */
#define DA_IS_NONROT 0
/* Queue Algorithm Modifier default for restricted reordering in control mode page */
#define DA_EMULATE_REST_REORD 0
#define SE_MODE_PAGE_BUF 512