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/*
* Generic SCSI - 3 ALUA SCSI Device Handler
*
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* Copyright ( C ) 2007 - 2010 Hannes Reinecke , SUSE Linux Products GmbH .
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* All rights reserved .
*
* This program is free software ; you can redistribute it and / or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation ; either version 2 of the License , or
* ( at your option ) any later version .
*
* This program is distributed in the hope that it will be useful ,
* but WITHOUT ANY WARRANTY ; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE . See the
* GNU General Public License for more details .
*
* You should have received a copy of the GNU General Public License
* along with this program ; if not , write to the Free Software
* Foundation , Inc . , 59 Temple Place - Suite 330 , Boston , MA 02111 - 1307 , USA .
*
*/
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
# include <linux/slab.h>
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# include <linux/delay.h>
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# include <linux/module.h>
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# include <scsi/scsi.h>
# include <scsi/scsi_eh.h>
# include <scsi/scsi_dh.h>
# define ALUA_DH_NAME "alua"
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# define ALUA_DH_VER "1.3"
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# define TPGS_STATE_OPTIMIZED 0x0
# define TPGS_STATE_NONOPTIMIZED 0x1
# define TPGS_STATE_STANDBY 0x2
# define TPGS_STATE_UNAVAILABLE 0x3
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# define TPGS_STATE_LBA_DEPENDENT 0x4
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# define TPGS_STATE_OFFLINE 0xe
# define TPGS_STATE_TRANSITIONING 0xf
# define TPGS_SUPPORT_NONE 0x00
# define TPGS_SUPPORT_OPTIMIZED 0x01
# define TPGS_SUPPORT_NONOPTIMIZED 0x02
# define TPGS_SUPPORT_STANDBY 0x04
# define TPGS_SUPPORT_UNAVAILABLE 0x08
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# define TPGS_SUPPORT_LBA_DEPENDENT 0x10
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# define TPGS_SUPPORT_OFFLINE 0x40
# define TPGS_SUPPORT_TRANSITION 0x80
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# define RTPG_FMT_MASK 0x70
# define RTPG_FMT_EXT_HDR 0x10
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# define TPGS_MODE_UNINITIALIZED -1
# define TPGS_MODE_NONE 0x0
# define TPGS_MODE_IMPLICIT 0x1
# define TPGS_MODE_EXPLICIT 0x2
# define ALUA_INQUIRY_SIZE 36
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# define ALUA_FAILOVER_TIMEOUT 60
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# define ALUA_FAILOVER_RETRIES 5
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/* flags passed from user level */
# define ALUA_OPTIMIZE_STPG 1
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struct alua_dh_data {
int group_id ;
int rel_port ;
int tpgs ;
int state ;
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int pref ;
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unsigned flags ; /* used for optimizing STPG */
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unsigned char inq [ ALUA_INQUIRY_SIZE ] ;
unsigned char * buff ;
int bufflen ;
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unsigned char transition_tmo ;
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unsigned char sense [ SCSI_SENSE_BUFFERSIZE ] ;
int senselen ;
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struct scsi_device * sdev ;
activate_complete callback_fn ;
void * callback_data ;
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} ;
# define ALUA_POLICY_SWITCH_CURRENT 0
# define ALUA_POLICY_SWITCH_ALL 1
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static char print_alua_state ( int ) ;
static int alua_check_sense ( struct scsi_device * , struct scsi_sense_hdr * ) ;
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static inline struct alua_dh_data * get_alua_data ( struct scsi_device * sdev )
{
struct scsi_dh_data * scsi_dh_data = sdev - > scsi_dh_data ;
BUG_ON ( scsi_dh_data = = NULL ) ;
return ( ( struct alua_dh_data * ) scsi_dh_data - > buf ) ;
}
static int realloc_buffer ( struct alua_dh_data * h , unsigned len )
{
if ( h - > buff & & h - > buff ! = h - > inq )
kfree ( h - > buff ) ;
h - > buff = kmalloc ( len , GFP_NOIO ) ;
if ( ! h - > buff ) {
h - > buff = h - > inq ;
h - > bufflen = ALUA_INQUIRY_SIZE ;
return 1 ;
}
h - > bufflen = len ;
return 0 ;
}
static struct request * get_alua_req ( struct scsi_device * sdev ,
void * buffer , unsigned buflen , int rw )
{
struct request * rq ;
struct request_queue * q = sdev - > request_queue ;
rq = blk_get_request ( q , rw , GFP_NOIO ) ;
if ( ! rq ) {
sdev_printk ( KERN_INFO , sdev ,
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" %s: blk_get_request failed \n " , __func__ ) ;
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return NULL ;
}
if ( buflen & & blk_rq_map_kern ( q , rq , buffer , buflen , GFP_NOIO ) ) {
blk_put_request ( rq ) ;
sdev_printk ( KERN_INFO , sdev ,
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" %s: blk_rq_map_kern failed \n " , __func__ ) ;
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return NULL ;
}
rq - > cmd_type = REQ_TYPE_BLOCK_PC ;
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rq - > cmd_flags | = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
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REQ_FAILFAST_DRIVER ;
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rq - > retries = ALUA_FAILOVER_RETRIES ;
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rq - > timeout = ALUA_FAILOVER_TIMEOUT * HZ ;
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return rq ;
}
/*
* submit_vpd_inquiry - Issue an INQUIRY VPD page 0x83 command
* @ sdev : sdev the command should be sent to
*/
static int submit_vpd_inquiry ( struct scsi_device * sdev , struct alua_dh_data * h )
{
struct request * rq ;
int err = SCSI_DH_RES_TEMP_UNAVAIL ;
rq = get_alua_req ( sdev , h - > buff , h - > bufflen , READ ) ;
if ( ! rq )
goto done ;
/* Prepare the command. */
rq - > cmd [ 0 ] = INQUIRY ;
rq - > cmd [ 1 ] = 1 ;
rq - > cmd [ 2 ] = 0x83 ;
rq - > cmd [ 4 ] = h - > bufflen ;
rq - > cmd_len = COMMAND_SIZE ( INQUIRY ) ;
rq - > sense = h - > sense ;
memset ( rq - > sense , 0 , SCSI_SENSE_BUFFERSIZE ) ;
rq - > sense_len = h - > senselen = 0 ;
err = blk_execute_rq ( rq - > q , NULL , rq , 1 ) ;
if ( err = = - EIO ) {
sdev_printk ( KERN_INFO , sdev ,
" %s: evpd inquiry failed with %x \n " ,
ALUA_DH_NAME , rq - > errors ) ;
h - > senselen = rq - > sense_len ;
err = SCSI_DH_IO ;
}
blk_put_request ( rq ) ;
done :
return err ;
}
/*
* submit_rtpg - Issue a REPORT TARGET GROUP STATES command
* @ sdev : sdev the command should be sent to
*/
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static unsigned submit_rtpg ( struct scsi_device * sdev , struct alua_dh_data * h ,
bool rtpg_ext_hdr_req )
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{
struct request * rq ;
int err = SCSI_DH_RES_TEMP_UNAVAIL ;
rq = get_alua_req ( sdev , h - > buff , h - > bufflen , READ ) ;
if ( ! rq )
goto done ;
/* Prepare the command. */
rq - > cmd [ 0 ] = MAINTENANCE_IN ;
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if ( rtpg_ext_hdr_req )
rq - > cmd [ 1 ] = MI_REPORT_TARGET_PGS | MI_EXT_HDR_PARAM_FMT ;
else
rq - > cmd [ 1 ] = MI_REPORT_TARGET_PGS ;
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rq - > cmd [ 6 ] = ( h - > bufflen > > 24 ) & 0xff ;
rq - > cmd [ 7 ] = ( h - > bufflen > > 16 ) & 0xff ;
rq - > cmd [ 8 ] = ( h - > bufflen > > 8 ) & 0xff ;
rq - > cmd [ 9 ] = h - > bufflen & 0xff ;
rq - > cmd_len = COMMAND_SIZE ( MAINTENANCE_IN ) ;
rq - > sense = h - > sense ;
memset ( rq - > sense , 0 , SCSI_SENSE_BUFFERSIZE ) ;
rq - > sense_len = h - > senselen = 0 ;
err = blk_execute_rq ( rq - > q , NULL , rq , 1 ) ;
if ( err = = - EIO ) {
sdev_printk ( KERN_INFO , sdev ,
" %s: rtpg failed with %x \n " ,
ALUA_DH_NAME , rq - > errors ) ;
h - > senselen = rq - > sense_len ;
err = SCSI_DH_IO ;
}
blk_put_request ( rq ) ;
done :
return err ;
}
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/*
* alua_stpg - Evaluate SET TARGET GROUP STATES
* @ sdev : the device to be evaluated
* @ state : the new target group state
*
* Send a SET TARGET GROUP STATES command to the device .
* We only have to test here if we should resubmit the command ;
* any other error is assumed as a failure .
*/
static void stpg_endio ( struct request * req , int error )
{
struct alua_dh_data * h = req - > end_io_data ;
struct scsi_sense_hdr sense_hdr ;
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unsigned err = SCSI_DH_OK ;
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if ( host_byte ( req - > errors ) ! = DID_OK | |
msg_byte ( req - > errors ) ! = COMMAND_COMPLETE ) {
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err = SCSI_DH_IO ;
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goto done ;
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}
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if ( req - > sense_len > 0 ) {
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err = scsi_normalize_sense ( h - > sense , SCSI_SENSE_BUFFERSIZE ,
& sense_hdr ) ;
if ( ! err ) {
err = SCSI_DH_IO ;
goto done ;
}
err = alua_check_sense ( h - > sdev , & sense_hdr ) ;
if ( err = = ADD_TO_MLQUEUE ) {
err = SCSI_DH_RETRY ;
goto done ;
}
sdev_printk ( KERN_INFO , h - > sdev ,
" %s: stpg sense code: %02x/%02x/%02x \n " ,
ALUA_DH_NAME , sense_hdr . sense_key ,
sense_hdr . asc , sense_hdr . ascq ) ;
err = SCSI_DH_IO ;
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} else if ( error )
err = SCSI_DH_IO ;
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if ( err = = SCSI_DH_OK ) {
h - > state = TPGS_STATE_OPTIMIZED ;
sdev_printk ( KERN_INFO , h - > sdev ,
" %s: port group %02x switched to state %c \n " ,
ALUA_DH_NAME , h - > group_id ,
print_alua_state ( h - > state ) ) ;
}
done :
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req - > end_io_data = NULL ;
__blk_put_request ( req - > q , req ) ;
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if ( h - > callback_fn ) {
h - > callback_fn ( h - > callback_data , err ) ;
h - > callback_fn = h - > callback_data = NULL ;
}
return ;
}
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/*
* submit_stpg - Issue a SET TARGET GROUP STATES command
*
* Currently we ' re only setting the current target port group state
* to ' active / optimized ' and let the array firmware figure out
* the states of the remaining groups .
*/
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static unsigned submit_stpg ( struct alua_dh_data * h )
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{
struct request * rq ;
int stpg_len = 8 ;
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struct scsi_device * sdev = h - > sdev ;
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/* Prepare the data buffer */
memset ( h - > buff , 0 , stpg_len ) ;
h - > buff [ 4 ] = TPGS_STATE_OPTIMIZED & 0x0f ;
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h - > buff [ 6 ] = ( h - > group_id > > 8 ) & 0xff ;
h - > buff [ 7 ] = h - > group_id & 0xff ;
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rq = get_alua_req ( sdev , h - > buff , stpg_len , WRITE ) ;
if ( ! rq )
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return SCSI_DH_RES_TEMP_UNAVAIL ;
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/* Prepare the command. */
rq - > cmd [ 0 ] = MAINTENANCE_OUT ;
rq - > cmd [ 1 ] = MO_SET_TARGET_PGS ;
rq - > cmd [ 6 ] = ( stpg_len > > 24 ) & 0xff ;
rq - > cmd [ 7 ] = ( stpg_len > > 16 ) & 0xff ;
rq - > cmd [ 8 ] = ( stpg_len > > 8 ) & 0xff ;
rq - > cmd [ 9 ] = stpg_len & 0xff ;
rq - > cmd_len = COMMAND_SIZE ( MAINTENANCE_OUT ) ;
rq - > sense = h - > sense ;
memset ( rq - > sense , 0 , SCSI_SENSE_BUFFERSIZE ) ;
rq - > sense_len = h - > senselen = 0 ;
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rq - > end_io_data = h ;
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blk_execute_rq_nowait ( rq - > q , NULL , rq , 1 , stpg_endio ) ;
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return SCSI_DH_OK ;
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}
/*
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* alua_check_tpgs - Evaluate TPGS setting
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* @ sdev : device to be checked
*
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* Examine the TPGS setting of the sdev to find out if ALUA
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* is supported .
*/
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static int alua_check_tpgs ( struct scsi_device * sdev , struct alua_dh_data * h )
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{
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int err = SCSI_DH_OK ;
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h - > tpgs = scsi_device_tpgs ( sdev ) ;
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switch ( h - > tpgs ) {
case TPGS_MODE_EXPLICIT | TPGS_MODE_IMPLICIT :
sdev_printk ( KERN_INFO , sdev ,
" %s: supports implicit and explicit TPGS \n " ,
ALUA_DH_NAME ) ;
break ;
case TPGS_MODE_EXPLICIT :
sdev_printk ( KERN_INFO , sdev , " %s: supports explicit TPGS \n " ,
ALUA_DH_NAME ) ;
break ;
case TPGS_MODE_IMPLICIT :
sdev_printk ( KERN_INFO , sdev , " %s: supports implicit TPGS \n " ,
ALUA_DH_NAME ) ;
break ;
default :
h - > tpgs = TPGS_MODE_NONE ;
sdev_printk ( KERN_INFO , sdev , " %s: not supported \n " ,
ALUA_DH_NAME ) ;
err = SCSI_DH_DEV_UNSUPP ;
break ;
}
return err ;
}
/*
* alua_vpd_inquiry - Evaluate INQUIRY vpd page 0x83
* @ sdev : device to be checked
*
* Extract the relative target port and the target port group
* descriptor from the list of identificators .
*/
static int alua_vpd_inquiry ( struct scsi_device * sdev , struct alua_dh_data * h )
{
int len ;
unsigned err ;
unsigned char * d ;
retry :
err = submit_vpd_inquiry ( sdev , h ) ;
if ( err ! = SCSI_DH_OK )
return err ;
/* Check if vpd page exceeds initial buffer */
len = ( h - > buff [ 2 ] < < 8 ) + h - > buff [ 3 ] + 4 ;
if ( len > h - > bufflen ) {
/* Resubmit with the correct length */
if ( realloc_buffer ( h , len ) ) {
sdev_printk ( KERN_WARNING , sdev ,
" %s: kmalloc buffer failed \n " ,
ALUA_DH_NAME ) ;
/* Temporary failure, bypass */
return SCSI_DH_DEV_TEMP_BUSY ;
}
goto retry ;
}
/*
* Now look for the correct descriptor .
*/
d = h - > buff + 4 ;
while ( d < h - > buff + len ) {
switch ( d [ 1 ] & 0xf ) {
case 0x4 :
/* Relative target port */
h - > rel_port = ( d [ 6 ] < < 8 ) + d [ 7 ] ;
break ;
case 0x5 :
/* Target port group */
h - > group_id = ( d [ 6 ] < < 8 ) + d [ 7 ] ;
break ;
default :
break ;
}
d + = d [ 3 ] + 4 ;
}
if ( h - > group_id = = - 1 ) {
/*
* Internal error ; TPGS supported but required
* VPD identification descriptors not present .
* Disable ALUA support
*/
sdev_printk ( KERN_INFO , sdev ,
" %s: No target port descriptors found \n " ,
ALUA_DH_NAME ) ;
h - > state = TPGS_STATE_OPTIMIZED ;
h - > tpgs = TPGS_MODE_NONE ;
err = SCSI_DH_DEV_UNSUPP ;
} else {
sdev_printk ( KERN_INFO , sdev ,
" %s: port group %02x rel port %02x \n " ,
ALUA_DH_NAME , h - > group_id , h - > rel_port ) ;
}
return err ;
}
static char print_alua_state ( int state )
{
switch ( state ) {
case TPGS_STATE_OPTIMIZED :
return ' A ' ;
case TPGS_STATE_NONOPTIMIZED :
return ' N ' ;
case TPGS_STATE_STANDBY :
return ' S ' ;
case TPGS_STATE_UNAVAILABLE :
return ' U ' ;
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case TPGS_STATE_LBA_DEPENDENT :
return ' L ' ;
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case TPGS_STATE_OFFLINE :
return ' O ' ;
case TPGS_STATE_TRANSITIONING :
return ' T ' ;
default :
return ' X ' ;
}
}
static int alua_check_sense ( struct scsi_device * sdev ,
struct scsi_sense_hdr * sense_hdr )
{
switch ( sense_hdr - > sense_key ) {
case NOT_READY :
if ( sense_hdr - > asc = = 0x04 & & sense_hdr - > ascq = = 0x0a )
/*
* LUN Not Accessible - ALUA state transition
*/
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return ADD_TO_MLQUEUE ;
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if ( sense_hdr - > asc = = 0x04 & & sense_hdr - > ascq = = 0x0b )
/*
* LUN Not Accessible - - Target port in standby state
*/
return SUCCESS ;
if ( sense_hdr - > asc = = 0x04 & & sense_hdr - > ascq = = 0x0c )
/*
* LUN Not Accessible - - Target port in unavailable state
*/
return SUCCESS ;
if ( sense_hdr - > asc = = 0x04 & & sense_hdr - > ascq = = 0x12 )
/*
* LUN Not Ready - - Offline
*/
return SUCCESS ;
break ;
case UNIT_ATTENTION :
if ( sense_hdr - > asc = = 0x29 & & sense_hdr - > ascq = = 0x00 )
/*
* Power On , Reset , or Bus Device Reset , just retry .
*/
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return ADD_TO_MLQUEUE ;
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if ( sense_hdr - > asc = = 0x2a & & sense_hdr - > ascq = = 0x01 )
/*
* Mode Parameters Changed
*/
return ADD_TO_MLQUEUE ;
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if ( sense_hdr - > asc = = 0x2a & & sense_hdr - > ascq = = 0x06 )
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/*
* ALUA state changed
*/
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return ADD_TO_MLQUEUE ;
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if ( sense_hdr - > asc = = 0x2a & & sense_hdr - > ascq = = 0x07 )
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/*
* Implicit ALUA state transition failed
*/
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return ADD_TO_MLQUEUE ;
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if ( sense_hdr - > asc = = 0x3f & & sense_hdr - > ascq = = 0x03 )
/*
* Inquiry data has changed
*/
return ADD_TO_MLQUEUE ;
if ( sense_hdr - > asc = = 0x3f & & sense_hdr - > ascq = = 0x0e )
2009-01-31 07:00:11 +08:00
/*
* REPORTED_LUNS_DATA_HAS_CHANGED is reported
* when switching controllers on targets like
* Intel Multi - Flex . We can just retry .
*/
return ADD_TO_MLQUEUE ;
2008-07-18 07:53:21 +08:00
break ;
}
return SCSI_RETURN_NOT_HANDLED ;
}
/*
* alua_rtpg - Evaluate REPORT TARGET GROUP STATES
* @ sdev : the device to be evaluated .
*
* Evaluate the Target Port Group State .
* Returns SCSI_DH_DEV_OFFLINED if the path is
2011-03-31 09:57:33 +08:00
* found to be unusable .
2008-07-18 07:53:21 +08:00
*/
static int alua_rtpg ( struct scsi_device * sdev , struct alua_dh_data * h )
{
struct scsi_sense_hdr sense_hdr ;
int len , k , off , valid_states = 0 ;
2011-08-24 16:51:18 +08:00
unsigned char * ucp ;
2008-07-18 07:53:21 +08:00
unsigned err ;
2012-05-19 02:08:55 +08:00
bool rtpg_ext_hdr_req = 1 ;
[SCSI] scsi_dh_alua: backoff alua rtpg retry linearly vs. geometrically
Currently the backoff algorithm for when to retry alua rtpg
requests progresses geometrically as so:
2, 4, 8, 16, 32, 64... seconds.
This progression can lead to un-needed delay in retrying
alua rtpg requests when the rtpgs are delayed. A less
aggressive backoff algorithm that is additive would not
lead to such large jumps when delays start getting long, but
would backoff linearly:
2, 4, 6, 8, 10... seconds.
Signed-off-by: Martin George <marting@netapp.com>
Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-05-19 02:08:56 +08:00
unsigned long expiry , interval = 0 ;
2012-05-19 02:08:54 +08:00
unsigned int tpg_desc_tbl_off ;
unsigned char orig_transition_tmo ;
if ( ! h - > transition_tmo )
expiry = round_jiffies_up ( jiffies + ALUA_FAILOVER_TIMEOUT * HZ ) ;
else
expiry = round_jiffies_up ( jiffies + h - > transition_tmo * HZ ) ;
2008-07-18 07:53:21 +08:00
retry :
2012-05-19 02:08:55 +08:00
err = submit_rtpg ( sdev , h , rtpg_ext_hdr_req ) ;
2008-07-18 07:53:21 +08:00
if ( err = = SCSI_DH_IO & & h - > senselen > 0 ) {
err = scsi_normalize_sense ( h - > sense , SCSI_SENSE_BUFFERSIZE ,
& sense_hdr ) ;
if ( ! err )
return SCSI_DH_IO ;
2012-05-19 02:08:55 +08:00
/*
* submit_rtpg ( ) has failed on existing arrays
* when requesting extended header info , and
* the array doesn ' t support extended headers ,
* even though it shouldn ' t according to T10 .
* The retry without rtpg_ext_hdr_req set
* handles this .
*/
if ( rtpg_ext_hdr_req = = 1 & &
sense_hdr . sense_key = = ILLEGAL_REQUEST & &
sense_hdr . asc = = 0x24 & & sense_hdr . ascq = = 0 ) {
rtpg_ext_hdr_req = 0 ;
goto retry ;
}
2008-07-18 07:53:21 +08:00
err = alua_check_sense ( sdev , & sense_hdr ) ;
2010-09-24 21:57:04 +08:00
if ( err = = ADD_TO_MLQUEUE & & time_before ( jiffies , expiry ) )
2008-07-18 07:53:21 +08:00
goto retry ;
sdev_printk ( KERN_INFO , sdev ,
" %s: rtpg sense code %02x/%02x/%02x \n " ,
ALUA_DH_NAME , sense_hdr . sense_key ,
sense_hdr . asc , sense_hdr . ascq ) ;
err = SCSI_DH_IO ;
}
if ( err ! = SCSI_DH_OK )
return err ;
len = ( h - > buff [ 0 ] < < 24 ) + ( h - > buff [ 1 ] < < 16 ) +
( h - > buff [ 2 ] < < 8 ) + h - > buff [ 3 ] + 4 ;
if ( len > h - > bufflen ) {
/* Resubmit with the correct length */
if ( realloc_buffer ( h , len ) ) {
sdev_printk ( KERN_WARNING , sdev ,
2008-07-04 14:47:27 +08:00
" %s: kmalloc buffer failed \n " , __func__ ) ;
2008-07-18 07:53:21 +08:00
/* Temporary failure, bypass */
return SCSI_DH_DEV_TEMP_BUSY ;
}
goto retry ;
}
2012-05-19 02:08:54 +08:00
orig_transition_tmo = h - > transition_tmo ;
if ( ( h - > buff [ 4 ] & RTPG_FMT_MASK ) = = RTPG_FMT_EXT_HDR & & h - > buff [ 5 ] ! = 0 )
h - > transition_tmo = h - > buff [ 5 ] ;
else
h - > transition_tmo = ALUA_FAILOVER_TIMEOUT ;
if ( orig_transition_tmo ! = h - > transition_tmo ) {
sdev_printk ( KERN_INFO , sdev ,
" %s: transition timeout set to %d seconds \n " ,
ALUA_DH_NAME , h - > transition_tmo ) ;
expiry = jiffies + h - > transition_tmo * HZ ;
}
if ( ( h - > buff [ 4 ] & RTPG_FMT_MASK ) = = RTPG_FMT_EXT_HDR )
tpg_desc_tbl_off = 8 ;
else
tpg_desc_tbl_off = 4 ;
for ( k = tpg_desc_tbl_off , ucp = h - > buff + tpg_desc_tbl_off ;
k < len ;
k + = off , ucp + = off ) {
2008-07-18 07:53:21 +08:00
if ( h - > group_id = = ( ucp [ 2 ] < < 8 ) + ucp [ 3 ] ) {
h - > state = ucp [ 0 ] & 0x0f ;
2012-03-28 04:56:08 +08:00
h - > pref = ucp [ 0 ] > > 7 ;
2008-07-18 07:53:21 +08:00
valid_states = ucp [ 1 ] ;
}
off = 8 + ( ucp [ 7 ] * 4 ) ;
}
sdev_printk ( KERN_INFO , sdev ,
2012-03-28 04:56:08 +08:00
" %s: port group %02x state %c %s supports %c%c%c%c%c%c%c \n " ,
2008-07-18 07:53:21 +08:00
ALUA_DH_NAME , h - > group_id , print_alua_state ( h - > state ) ,
2012-03-28 04:56:08 +08:00
h - > pref ? " preferred " : " non-preferred " ,
2008-07-18 07:53:21 +08:00
valid_states & TPGS_SUPPORT_TRANSITION ? ' T ' : ' t ' ,
valid_states & TPGS_SUPPORT_OFFLINE ? ' O ' : ' o ' ,
2010-09-24 21:57:04 +08:00
valid_states & TPGS_SUPPORT_LBA_DEPENDENT ? ' L ' : ' l ' ,
2008-07-18 07:53:21 +08:00
valid_states & TPGS_SUPPORT_UNAVAILABLE ? ' U ' : ' u ' ,
valid_states & TPGS_SUPPORT_STANDBY ? ' S ' : ' s ' ,
valid_states & TPGS_SUPPORT_NONOPTIMIZED ? ' N ' : ' n ' ,
valid_states & TPGS_SUPPORT_OPTIMIZED ? ' A ' : ' a ' ) ;
2010-09-24 21:57:04 +08:00
switch ( h - > state ) {
case TPGS_STATE_TRANSITIONING :
if ( time_before ( jiffies , expiry ) ) {
2008-07-18 07:53:21 +08:00
/* State transition, retry */
[SCSI] scsi_dh_alua: backoff alua rtpg retry linearly vs. geometrically
Currently the backoff algorithm for when to retry alua rtpg
requests progresses geometrically as so:
2, 4, 8, 16, 32, 64... seconds.
This progression can lead to un-needed delay in retrying
alua rtpg requests when the rtpgs are delayed. A less
aggressive backoff algorithm that is additive would not
lead to such large jumps when delays start getting long, but
would backoff linearly:
2, 4, 6, 8, 10... seconds.
Signed-off-by: Martin George <marting@netapp.com>
Signed-off-by: Rob Evers <revers@redhat.com>
Reviewed-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-05-19 02:08:56 +08:00
interval + = 2000 ;
2010-09-24 21:57:04 +08:00
msleep ( interval ) ;
2008-07-18 07:53:21 +08:00
goto retry ;
}
2010-09-24 21:57:04 +08:00
/* Transitioning time exceeded, set port to standby */
err = SCSI_DH_RETRY ;
h - > state = TPGS_STATE_STANDBY ;
break ;
case TPGS_STATE_OFFLINE :
2012-08-24 17:08:41 +08:00
/* Path unusable */
2010-09-24 21:57:04 +08:00
err = SCSI_DH_DEV_OFFLINED ;
break ;
default :
/* Useable path if active */
err = SCSI_DH_OK ;
break ;
2008-07-18 07:53:21 +08:00
}
return err ;
}
/*
* alua_initialize - Initialize ALUA state
* @ sdev : the device to be initialized
*
* For the prep_fn to work correctly we have
* to initialize the ALUA state for the device .
*/
static int alua_initialize ( struct scsi_device * sdev , struct alua_dh_data * h )
{
int err ;
2011-08-24 16:51:13 +08:00
err = alua_check_tpgs ( sdev , h ) ;
2008-07-18 07:53:21 +08:00
if ( err ! = SCSI_DH_OK )
goto out ;
err = alua_vpd_inquiry ( sdev , h ) ;
if ( err ! = SCSI_DH_OK )
goto out ;
err = alua_rtpg ( sdev , h ) ;
if ( err ! = SCSI_DH_OK )
goto out ;
out :
return err ;
}
2012-03-28 04:55:49 +08:00
/*
* alua_set_params - set / unset the optimize flag
* @ sdev : device on the path to be activated
* params - parameters in the following format
* " no_of_params \0 param1 \0 param2 \0 param3 \0 ... \0 "
* For example , to set the flag pass the following parameters
* from multipath . conf
* hardware_handler " 2 alua 1 "
*/
static int alua_set_params ( struct scsi_device * sdev , const char * params )
{
struct alua_dh_data * h = get_alua_data ( sdev ) ;
unsigned int optimize = 0 , argc ;
const char * p = params ;
int result = SCSI_DH_OK ;
if ( ( sscanf ( params , " %u " , & argc ) ! = 1 ) | | ( argc ! = 1 ) )
return - EINVAL ;
while ( * p + + )
;
if ( ( sscanf ( p , " %u " , & optimize ) ! = 1 ) | | ( optimize > 1 ) )
return - EINVAL ;
if ( optimize )
h - > flags | = ALUA_OPTIMIZE_STPG ;
else
h - > flags & = ~ ALUA_OPTIMIZE_STPG ;
return result ;
}
2008-07-18 07:53:21 +08:00
2013-04-04 22:54:47 +08:00
static uint optimize_stpg ;
module_param ( optimize_stpg , uint , S_IRUGO | S_IWUSR ) ;
MODULE_PARM_DESC ( optimize_stpg , " Allow use of a non-optimized path, rather than sending a STPG, when implicit TPGS is supported (0=No,1=Yes). Default is 0. " ) ;
2008-07-18 07:53:21 +08:00
/*
* alua_activate - activate a path
* @ sdev : device on the path to be activated
*
* We ' re currently switching the port group to be activated only and
* let the array figure out the rest .
* There may be other arrays which require us to switch all port groups
* based on a certain policy . But until we actually encounter them it
* should be okay .
*/
2009-10-22 00:22:46 +08:00
static int alua_activate ( struct scsi_device * sdev ,
activate_complete fn , void * data )
2008-07-18 07:53:21 +08:00
{
struct alua_dh_data * h = get_alua_data ( sdev ) ;
int err = SCSI_DH_OK ;
2012-03-28 04:56:20 +08:00
int stpg = 0 ;
2008-07-18 07:53:21 +08:00
2011-08-24 16:51:16 +08:00
err = alua_rtpg ( sdev , h ) ;
if ( err ! = SCSI_DH_OK )
goto out ;
2008-07-18 07:53:21 +08:00
2013-04-04 22:54:47 +08:00
if ( optimize_stpg )
h - > flags | = ALUA_OPTIMIZE_STPG ;
2012-03-28 04:56:20 +08:00
if ( h - > tpgs & TPGS_MODE_EXPLICIT ) {
switch ( h - > state ) {
case TPGS_STATE_NONOPTIMIZED :
stpg = 1 ;
if ( ( h - > flags & ALUA_OPTIMIZE_STPG ) & &
( ! h - > pref ) & &
( h - > tpgs & TPGS_MODE_IMPLICIT ) )
stpg = 0 ;
break ;
case TPGS_STATE_STANDBY :
2012-06-22 16:49:38 +08:00
case TPGS_STATE_UNAVAILABLE :
2012-03-28 04:56:20 +08:00
stpg = 1 ;
break ;
case TPGS_STATE_OFFLINE :
err = SCSI_DH_IO ;
break ;
case TPGS_STATE_TRANSITIONING :
err = SCSI_DH_RETRY ;
break ;
default :
break ;
}
}
if ( stpg ) {
2009-10-22 00:23:04 +08:00
h - > callback_fn = fn ;
h - > callback_data = data ;
err = submit_stpg ( h ) ;
if ( err = = SCSI_DH_OK )
return 0 ;
h - > callback_fn = h - > callback_data = NULL ;
}
2008-07-18 07:53:21 +08:00
out :
2009-10-22 00:22:46 +08:00
if ( fn )
fn ( data , err ) ;
return 0 ;
2008-07-18 07:53:21 +08:00
}
/*
* alua_prep_fn - request callback
*
* Fail I / O to all paths not in state
* active / optimized or active / non - optimized .
*/
static int alua_prep_fn ( struct scsi_device * sdev , struct request * req )
{
struct alua_dh_data * h = get_alua_data ( sdev ) ;
int ret = BLKPREP_OK ;
2010-09-24 21:57:04 +08:00
if ( h - > state = = TPGS_STATE_TRANSITIONING )
ret = BLKPREP_DEFER ;
else if ( h - > state ! = TPGS_STATE_OPTIMIZED & &
h - > state ! = TPGS_STATE_NONOPTIMIZED & &
h - > state ! = TPGS_STATE_LBA_DEPENDENT ) {
2008-07-18 07:53:21 +08:00
ret = BLKPREP_KILL ;
req - > cmd_flags | = REQ_QUIET ;
}
return ret ;
}
2011-08-24 16:51:15 +08:00
static bool alua_match ( struct scsi_device * sdev )
{
return ( scsi_device_tpgs ( sdev ) ! = 0 ) ;
}
2008-07-18 07:53:21 +08:00
static int alua_bus_attach ( struct scsi_device * sdev ) ;
static void alua_bus_detach ( struct scsi_device * sdev ) ;
static struct scsi_device_handler alua_dh = {
. name = ALUA_DH_NAME ,
. module = THIS_MODULE ,
. attach = alua_bus_attach ,
. detach = alua_bus_detach ,
. prep_fn = alua_prep_fn ,
. check_sense = alua_check_sense ,
. activate = alua_activate ,
2012-03-28 04:55:49 +08:00
. set_params = alua_set_params ,
2011-08-24 16:51:15 +08:00
. match = alua_match ,
2008-07-18 07:53:21 +08:00
} ;
/*
* alua_bus_attach - Attach device handler
* @ sdev : device to be attached to
*/
static int alua_bus_attach ( struct scsi_device * sdev )
{
struct scsi_dh_data * scsi_dh_data ;
struct alua_dh_data * h ;
unsigned long flags ;
int err = SCSI_DH_OK ;
2011-02-12 06:17:33 +08:00
scsi_dh_data = kzalloc ( sizeof ( * scsi_dh_data )
2008-07-18 07:53:21 +08:00
+ sizeof ( * h ) , GFP_KERNEL ) ;
if ( ! scsi_dh_data ) {
sdev_printk ( KERN_ERR , sdev , " %s: Attach failed \n " ,
ALUA_DH_NAME ) ;
return - ENOMEM ;
}
scsi_dh_data - > scsi_dh = & alua_dh ;
h = ( struct alua_dh_data * ) scsi_dh_data - > buf ;
h - > tpgs = TPGS_MODE_UNINITIALIZED ;
h - > state = TPGS_STATE_OPTIMIZED ;
h - > group_id = - 1 ;
h - > rel_port = - 1 ;
h - > buff = h - > inq ;
h - > bufflen = ALUA_INQUIRY_SIZE ;
2009-10-22 00:23:04 +08:00
h - > sdev = sdev ;
2008-07-18 07:53:21 +08:00
err = alua_initialize ( sdev , h ) ;
2011-04-26 20:57:05 +08:00
if ( ( err ! = SCSI_DH_OK ) & & ( err ! = SCSI_DH_DEV_OFFLINED ) )
2008-07-18 07:53:21 +08:00
goto failed ;
if ( ! try_module_get ( THIS_MODULE ) )
goto failed ;
spin_lock_irqsave ( sdev - > request_queue - > queue_lock , flags ) ;
sdev - > scsi_dh_data = scsi_dh_data ;
spin_unlock_irqrestore ( sdev - > request_queue - > queue_lock , flags ) ;
2011-10-28 02:36:32 +08:00
sdev_printk ( KERN_NOTICE , sdev , " %s: Attached \n " , ALUA_DH_NAME ) ;
2008-07-18 07:53:21 +08:00
return 0 ;
failed :
kfree ( scsi_dh_data ) ;
sdev_printk ( KERN_ERR , sdev , " %s: not attached \n " , ALUA_DH_NAME ) ;
return - EINVAL ;
}
/*
* alua_bus_detach - Detach device handler
* @ sdev : device to be detached from
*/
static void alua_bus_detach ( struct scsi_device * sdev )
{
struct scsi_dh_data * scsi_dh_data ;
struct alua_dh_data * h ;
unsigned long flags ;
spin_lock_irqsave ( sdev - > request_queue - > queue_lock , flags ) ;
scsi_dh_data = sdev - > scsi_dh_data ;
sdev - > scsi_dh_data = NULL ;
spin_unlock_irqrestore ( sdev - > request_queue - > queue_lock , flags ) ;
h = ( struct alua_dh_data * ) scsi_dh_data - > buf ;
if ( h - > buff & & h - > inq ! = h - > buff )
kfree ( h - > buff ) ;
kfree ( scsi_dh_data ) ;
module_put ( THIS_MODULE ) ;
sdev_printk ( KERN_NOTICE , sdev , " %s: Detached \n " , ALUA_DH_NAME ) ;
}
static int __init alua_init ( void )
{
int r ;
r = scsi_register_device_handler ( & alua_dh ) ;
if ( r ! = 0 )
printk ( KERN_ERR " %s: Failed to register scsi device handler " ,
ALUA_DH_NAME ) ;
return r ;
}
static void __exit alua_exit ( void )
{
scsi_unregister_device_handler ( & alua_dh ) ;
}
module_init ( alua_init ) ;
module_exit ( alua_exit ) ;
MODULE_DESCRIPTION ( " DM Multipath ALUA support " ) ;
MODULE_AUTHOR ( " Hannes Reinecke <hare@suse.de> " ) ;
MODULE_LICENSE ( " GPL " ) ;
MODULE_VERSION ( ALUA_DH_VER ) ;