RE: eata irq abuse (was: Re: Linux 2.5.60)

RE: eata irq abuse (was: Re: Linux 2.5.60)

[Ballabio_Dario]

Yes, you are correct. I used spin_unlock in order to release the local
driver lock
during the scsi_register call, but I forgot that I had the irq disabled as
well.
SO the correct fix is to use spin_unlock_irq/spin_lock_irq around the
scsi_register call. Same fix applies to the u14-34f driver.

Cheers,

*********************************
Ph.D. Dario Ballabio
EMC Computer Systems Italia spa
Mobile phone +393487978851
Office phone +390244571315
Mobile fax   +393487951622

*** Si vis pacem, para bellum ***


-----Original Message-----
From: Manfred Spraul [mailto:manfred@colorfullife.com]
Sent: Tuesday, February 11, 2003 6:46 PM
To: Zephaniah E. Hull
Cc: linux-kernel@vger.kernel.org; linux-scsi@vger.kernel.org;
linux-eata@i-connect.net
Subject: eata irq abuse (was: Re: Linux 2.5.60)


Zephaniah wrote:

>kernel BUG at mm/slab.c:1102!

Slab notices that a function that expects enabled local interrupts is called
with disabled local interrupts.


>Call Trace:
> [<c014a3b3>] do_tune_cpucache+0x83/0x240

do_tune_cpucache:
the function call smp_call_function(), and that is only permitted with
enabled local interrupts. The complain is correct.


> [<c014a300>] do_ccpupdate_local+0x0/0x30
> [<c014a5c1>] enable_cpucache+0x51/0x80
> [<c0148ea5>] kmem_cache_create+0x4a5/0x560

Within kmem_cache_create. kmem_cache_create checks for in_interrupt(), thus
someone probably does

	spin_lock_irqsave();
	kmem_cache_create();


> [<c0285dd2>] scsi_setup_command_freelist+0xa2/0x130

calls kmem_cache_create()

> [<c02887e0>] scsi_register+0x3c0/0x660

calls scsi_setup_command_freelist


> [<c02919a1>] get_pci_dev+0x31/0x50

?? probably stale

> [<c0291df2>] port_detect+0x3c2/0xe50

Do you have an eata scsi controller?

Ugs.
eata2x_detect():
* spin_lock_irqsave();
* calls port_detect();
* * spin_unlock();
* * scsi_register.

Eata maintainers: Is that necessary?
Why do the interrupts remain disabled across scsi_register?
Is that a bug workaround, or an oversight?
I'd use

	spin_unlock_irq();
	scsi_register();
	spin_lock_irq();

--
	Manfred


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Re: eata irq abuse (was: Re: Linux 2.5.60)

[Jeff Garzik]

Ballabio_Dario@emc.com wrote:
> Yes, you are correct. I used spin_unlock in order to release the local
> driver lock
> during the scsi_register call, but I forgot that I had the irq disabled as
> well.
> SO the correct fix is to use spin_unlock_irq/spin_lock_irq around the
> scsi_register call. Same fix applies to the u14-34f driver.


scsi_register may want to sleep, so that is not a fix at all...

Re: eata irq abuse (was: Re: Linux 2.5.60)

[Jeff Garzik]

Jeff Garzik wrote:
> Ballabio_Dario@emc.com wrote:
> 
>> Yes, you are correct. I used spin_unlock in order to release the local
>> driver lock
>> during the scsi_register call, but I forgot that I had the irq 
>> disabled as
>> well.
>> SO the correct fix is to use spin_unlock_irq/spin_lock_irq around the
>> scsi_register call. Same fix applies to the u14-34f driver.
> 
> scsi_register may want to sleep, so that is not a fix at all...


Ooops, I missed the order.  You (and Manfred) are right, 
unlock-register-lock is desired.

ENOCAFFEINE, I plead...

RE: eata irq abuse (was: Re: Linux 2.5.60)

[Suresh Kr N]

hi everyone

I am working on a san management application for a linux. My application
sends zoning commands to the fabric to zone in a disk to a host ,  so i need
to have that disk acessible to the host without a reboot of the host.

I need to do this from the user space. Is there a way to ask the scsi
midlayer for a rescan ?
In solaris , i invoke a command called "drvconfig" to achieve this.

I have seen in the linux-scsi archive that this is kind of possible,  but
the discussion didnt seem to state how.
I am attaching the above thread here in the mail.

I have verified that echo "scsi add-single-device a b c d" > /proc/scsi/scsi
works fine . But this does involve parameters which cant be found out
programmatically.

Also a side question here :In a FC world, to get the target number for above
command , can i find out the current maximum target number of the scsi
devices, and increase it by one ? or  does the FC devices have actually a
preknown target no , which would be collected by the FC card driver ?

Could someone please help ? ( even a "non-standard" way should be good
enough" )

Thanks
Suresh



--------------------------------------------------------
Message 2 in thread
From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Subject: Re: Hot plugging a disk in runtime
View this article only
Newsgroups: mlist.linux.scsi
Date: 2002-05-20 05:32:38 PST


> 1.. How is it possible to signal SCSI mid-layer (or other layers) of a
> presence of a newly hot-plugged disk ?

aacraid is one example that does this, but via its config tools.

> 2.. Can an adapter's device driver trigger SCSI subsystem to scan
> channels for new LUNs / Targets ?

It is designed so user space can do so - so yes

> 3.. Is this can be handled in a kernel level ? is there a user space
> application that can be triggered to start scanning adapters (obviously
> through SCSI subsystem) and registering new LUNs / Targets etc... ?

echo "scsi-add-single-device a b c d" /proc/scsi/scsi

if I remember it right


entire thread is at

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=linux.scsi.200205
201420.g4KEK3x01892%40localhost.localdomain&rnum=7&prev=/groups%3Fq%3Dhot%2B
plug%2B%2BSCSI%2Bfibre-channel%2BLinux%26hl%3Den%26lr%3D%26ie%3DUTF-8%26selm
%3Dlinux.scsi.200205201420.g4KEK3x01892%2540localhost.localdomain%26rnum%3D7

Adding a new FC disk to a linux host

[Suresh Kr N]

sorry about the wrong thread name in the previous post. updated now


hi everyone

I am working on a san management application for a linux. My application
sends zoning commands to the fabric to zone in a disk to a host ,  so i need
to have that disk acessible to the host without a reboot of the host.

I need to do this from the user space. Is there a way to ask the scsi
midlayer for a rescan ?
In solaris , i invoke a command called "drvconfig" to achieve this.

I have seen in the linux-scsi archive that this is kind of possible,  but
the discussion didnt seem to state how.
I am attaching the above thread here in the mail.

I have verified that echo "scsi add-single-device a b c d" > /proc/scsi/scsi
works fine . But this does involve parameters which cant be found out
programmatically.

Also a side question here :In a FC world, to get the target number for above
command , can i find out the current maximum target number of the scsi
devices, and increase it by one ? or  does the FC devices have actually a
preknown target no , which would be collected by the FC card driver ?

Could someone please help ? ( even a "non-standard" way should be good
enough" )

Thanks
Suresh



--------------------------------------------------------
Message 2 in thread
From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Subject: Re: Hot plugging a disk in runtime
View this article only
Newsgroups: mlist.linux.scsi
Date: 2002-05-20 05:32:38 PST


> 1.. How is it possible to signal SCSI mid-layer (or other layers) of a
> presence of a newly hot-plugged disk ?

aacraid is one example that does this, but via its config tools.

> 2.. Can an adapter's device driver trigger SCSI subsystem to scan
> channels for new LUNs / Targets ?

It is designed so user space can do so - so yes

> 3.. Is this can be handled in a kernel level ? is there a user space
> application that can be triggered to start scanning adapters (obviously
> through SCSI subsystem) and registering new LUNs / Targets etc... ?

echo "scsi-add-single-device a b c d" /proc/scsi/scsi

if I remember it right


entire thread is at

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=linux.scsi.200205
201420.g4KEK3x01892%40localhost.localdomain&rnum=7&prev=/groups%3Fq%3Dhot%2B
plug%2B%2BSCSI%2Bfibre-channel%2BLinux%26hl%3Den%26lr%3D%26ie%3DUTF-8%26selm
%3Dlinux.scsi.200205201420.g4KEK3x01892%2540localhost.localdomain%26rnum%3D7

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To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
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Re: Adding a new FC disk to a linux host

[Steven Dake]

you can scan specific scsi ids.  read scsi_proc.c search for 
add-single-device

         * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
         * Consider this feature BETA.


Good luck
-steve

Suresh Kr N wrote:

>sorry about the wrong thread name in the previous post. updated now
>
>
>hi everyone
>
>I am working on a san management application for a linux. My application
>sends zoning commands to the fabric to zone in a disk to a host ,  so i need
>to have that disk acessible to the host without a reboot of the host.
>
>I need to do this from the user space. Is there a way to ask the scsi
>midlayer for a rescan ?
>In solaris , i invoke a command called "drvconfig" to achieve this.
>
>I have seen in the linux-scsi archive that this is kind of possible,  but
>the discussion didnt seem to state how.
>I am attaching the above thread here in the mail.
>
>I have verified that echo "scsi add-single-device a b c d" > /proc/scsi/scsi
>works fine . But this does involve parameters which cant be found out
>programmatically.
>
>Also a side question here :In a FC world, to get the target number for above
>command , can i find out the current maximum target number of the scsi
>devices, and increase it by one ? or  does the FC devices have actually a
>preknown target no , which would be collected by the FC card driver ?
>
>Could someone please help ? ( even a "non-standard" way should be good
>enough" )
>
>Thanks
>Suresh
>
>
>
>--------------------------------------------------------
>Message 2 in thread
>From: Alan Cox (alan@lxorguk.ukuu.org.uk)
>Subject: Re: Hot plugging a disk in runtime
>View this article only
>Newsgroups: mlist.linux.scsi
>Date: 2002-05-20 05:32:38 PST
>
>
>  
>
>>1.. How is it possible to signal SCSI mid-layer (or other layers) of a
>>presence of a newly hot-plugged disk ?
>>    
>>
>
>aacraid is one example that does this, but via its config tools.
>
>  
>
>>2.. Can an adapter's device driver trigger SCSI subsystem to scan
>>channels for new LUNs / Targets ?
>>    
>>
>
>It is designed so user space can do so - so yes
>
>  
>
>>3.. Is this can be handled in a kernel level ? is there a user space
>>application that can be triggered to start scanning adapters (obviously
>>through SCSI subsystem) and registering new LUNs / Targets etc... ?
>>    
>>
>
>echo "scsi-add-single-device a b c d" /proc/scsi/scsi
>
>if I remember it right
>
>
>entire thread is at
>
>http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=linux.scsi.200205
>201420.g4KEK3x01892%40localhost.localdomain&rnum=7&prev=/groups%3Fq%3Dhot%2B
>plug%2B%2BSCSI%2Bfibre-channel%2BLinux%26hl%3Den%26lr%3D%26ie%3DUTF-8%26selm
>%3Dlinux.scsi.200205201420.g4KEK3x01892%2540localhost.localdomain%26rnum%3D7
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>
>  
>

RE: Adding a new FC disk to a linux host

[Suresh Kr N]

This works for me ( by the way is this still BETA ? i dont see this comment
in the kernel scsi sources anymore ).
But then i need to deduce the these input parameters of target no , lun no
etc , as i need to do this from a userland san management app.

I figured that the HBA apis give you the new target number , and probably i
could do a report luns or something to get the lun numbers as well. So this
way could work for me .

Is there a way to ask the midlayer for a full rescan ( so that i wont have
to find out these parameters )

suresh


-----Original Message-----
From: linux-scsi-owner@vger.kernel.org
[mailto:linux-scsi-owner@vger.kernel.org]On Behalf Of Steven Dake
Sent: Thursday, February 13, 2003 5:05 AM
To: Suresh Kr N
Cc: linux-scsi@vger.kernel.org
Subject: Re: Adding a new FC disk to a linux host


you can scan specific scsi ids.  read scsi_proc.c search for
add-single-device

         * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
         * Consider this feature BETA.


Good luck
-steve

Suresh Kr N wrote:

>sorry about the wrong thread name in the previous post. updated now
>
>
>hi everyone
>
>I am working on a san management application for a linux. My application
>sends zoning commands to the fabric to zone in a disk to a host ,  so i
need
>to have that disk acessible to the host without a reboot of the host.
>
>I need to do this from the user space. Is there a way to ask the scsi
>midlayer for a rescan ?
>In solaris , i invoke a command called "drvconfig" to achieve this.
>
>I have seen in the linux-scsi archive that this is kind of possible,  but
>the discussion didnt seem to state how.
>I am attaching the above thread here in the mail.
>
>I have verified that echo "scsi add-single-device a b c d" >
/proc/scsi/scsi
>works fine . But this does involve parameters which cant be found out
>programmatically.
>
>Also a side question here :In a FC world, to get the target number for
above
>command , can i find out the current maximum target number of the scsi
>devices, and increase it by one ? or  does the FC devices have actually a
>preknown target no , which would be collected by the FC card driver ?
>
>Could someone please help ? ( even a "non-standard" way should be good
>enough" )
>
>Thanks
>Suresh
>
>
>
>--------------------------------------------------------
>Message 2 in thread
>From: Alan Cox (alan@lxorguk.ukuu.org.uk)
>Subject: Re: Hot plugging a disk in runtime
>View this article only
>Newsgroups: mlist.linux.scsi
>Date: 2002-05-20 05:32:38 PST
>
>
>
>
>>1.. How is it possible to signal SCSI mid-layer (or other layers) of a
>>presence of a newly hot-plugged disk ?
>>
>>
>
>aacraid is one example that does this, but via its config tools.
>
>
>
>>2.. Can an adapter's device driver trigger SCSI subsystem to scan
>>channels for new LUNs / Targets ?
>>
>>
>
>It is designed so user space can do so - so yes
>
>
>
>>3.. Is this can be handled in a kernel level ? is there a user space
>>application that can be triggered to start scanning adapters (obviously
>>through SCSI subsystem) and registering new LUNs / Targets etc... ?
>>
>>
>
>echo "scsi-add-single-device a b c d" /proc/scsi/scsi
>
>if I remember it right
>
>
>entire thread is at
>
>http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=linux.scsi.20020
5
>201420.g4KEK3x01892%40localhost.localdomain&rnum=7&prev=/groups%3Fq%3Dhot%2
B
>plug%2B%2BSCSI%2Bfibre-channel%2BLinux%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sel
m
>%3Dlinux.scsi.200205201420.g4KEK3x01892%2540localhost.localdomain%26rnum%3D
7
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>
>
>

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RE: Adding a new FC disk to a linux host

[Suresh Kr N]

ok , i see this in scsi.c .
Is this safe in a Fibre channel SAN scenario ? could it corrupt an ongoing
data tranfer in a fibre channel SAN scenario ?
and also are there are easier ways to achieve this ( without you supplying a
scsi id etc ).

suresh

  /*
         * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
         * Consider this feature BETA.
         *     CAUTION: This is not for hotplugging your peripherals. As
         *     SCSI was not designed for this you could damage your
         *     hardware !
         * However perhaps it is legal to switch on an
         * already connected device. It is perhaps not
         * guaranteed this device doesn't corrupt an ongoing data transfer.
         */

-----Original Message-----
From: linux-scsi-owner@vger.kernel.org
[mailto:linux-scsi-owner@vger.kernel.org]On Behalf Of Suresh Kr N
Sent: Thursday, February 13, 2003 11:01 PM
To: Steven Dake
Cc: linux-scsi@vger.kernel.org
Subject: RE: Adding a new FC disk to a linux host


This works for me ( by the way is this still BETA ? i dont see this comment
in the kernel scsi sources anymore ).
But then i need to deduce the these input parameters of target no , lun no
etc , as i need to do this from a userland san management app.

I figured that the HBA apis give you the new target number , and probably i
could do a report luns or something to get the lun numbers as well. So this
way could work for me .

Is there a way to ask the midlayer for a full rescan ( so that i wont have
to find out these parameters )

suresh


-----Original Message-----
From: linux-scsi-owner@vger.kernel.org
[mailto:linux-scsi-owner@vger.kernel.org]On Behalf Of Steven Dake
Sent: Thursday, February 13, 2003 5:05 AM
To: Suresh Kr N
Cc: linux-scsi@vger.kernel.org
Subject: Re: Adding a new FC disk to a linux host


you can scan specific scsi ids.  read scsi_proc.c search for
add-single-device

         * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
         * Consider this feature BETA.


Good luck
-steve

Suresh Kr N wrote:

>sorry about the wrong thread name in the previous post. updated now
>
>
>hi everyone
>
>I am working on a san management application for a linux. My application
>sends zoning commands to the fabric to zone in a disk to a host ,  so i
need
>to have that disk acessible to the host without a reboot of the host.
>
>I need to do this from the user space. Is there a way to ask the scsi
>midlayer for a rescan ?
>In solaris , i invoke a command called "drvconfig" to achieve this.
>
>I have seen in the linux-scsi archive that this is kind of possible,  but
>the discussion didnt seem to state how.
>I am attaching the above thread here in the mail.
>
>I have verified that echo "scsi add-single-device a b c d" >
/proc/scsi/scsi
>works fine . But this does involve parameters which cant be found out
>programmatically.
>
>Also a side question here :In a FC world, to get the target number for
above
>command , can i find out the current maximum target number of the scsi
>devices, and increase it by one ? or  does the FC devices have actually a
>preknown target no , which would be collected by the FC card driver ?
>
>Could someone please help ? ( even a "non-standard" way should be good
>enough" )
>
>Thanks
>Suresh
>
>
>
>--------------------------------------------------------
>Message 2 in thread
>From: Alan Cox (alan@lxorguk.ukuu.org.uk)
>Subject: Re: Hot plugging a disk in runtime
>View this article only
>Newsgroups: mlist.linux.scsi
>Date: 2002-05-20 05:32:38 PST
>
>
>
>
>>1.. How is it possible to signal SCSI mid-layer (or other layers) of a
>>presence of a newly hot-plugged disk ?
>>
>>
>
>aacraid is one example that does this, but via its config tools.
>
>
>
>>2.. Can an adapter's device driver trigger SCSI subsystem to scan
>>channels for new LUNs / Targets ?
>>
>>
>
>It is designed so user space can do so - so yes
>
>
>
>>3.. Is this can be handled in a kernel level ? is there a user space
>>application that can be triggered to start scanning adapters (obviously
>>through SCSI subsystem) and registering new LUNs / Targets etc... ?
>>
>>
>
>echo "scsi-add-single-device a b c d" /proc/scsi/scsi
>
>if I remember it right
>
>
>entire thread is at
>
>http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=linux.scsi.20020
5
>201420.g4KEK3x01892%40localhost.localdomain&rnum=7&prev=/groups%3Fq%3Dhot%2
B
>plug%2B%2BSCSI%2Bfibre-channel%2BLinux%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sel
m
>%3Dlinux.scsi.200205201420.g4KEK3x01892%2540localhost.localdomain%26rnum%3D
7
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>
>
>

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Re: Adding a new FC disk to a linux host

[Steven Dake]

Suresh,

The locking of the SCSI devices is not correct in the SCSI midlayer, 
resulting in potential linked list walk-offs during insertion on one 
processor and removal on another processor in the system.  There are 
other problems even for single-processor configurations.

I have partially fixed this, but my patch is incomplete and i've not had 
time to revise it so it is correct.

If you want to insert by FibreChannel WWN, you can look at
www.sourceforge.net/projects/atca-hotswap.

This allows insertion by a FC WWN via a kernel patch and provides a 
userspace library to do the same.  This patch was mainly made for 2.4 
where there was no way to correlate a FibreChannel WWN with a scsi 
target ID.  Since sysfs in linux scsi has added FibreChannel IEEE ID 
support (wwns), I will eventually change the userspace library to do the 
correct thing when you request an insertion on a fibrechannel id by 
scanning the scsi list in sysfs and finding the correct 
host/channel/id/lun on which to insert and doing the insert 
automatically.  If you want to write that hotswap library code, i'll put 
it in to the sourceforge project.

It would also be possible to request that the fibrehcannel device list 
out its supproted scsi target ids, and compare that to the SCSI layer's 
view, and automatically insert those that are not in the scsi midlayer. 
 Exercise for the reader.

Thanks!
-steve

Suresh Kr N wrote:

>ok , i see this in scsi.c .
>Is this safe in a Fibre channel SAN scenario ? could it corrupt an ongoing
>data tranfer in a fibre channel SAN scenario ?
>and also are there are easier ways to achieve this ( without you supplying a
>scsi id etc ).
>
>suresh
>
>  /*
>         * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
>         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
>         * Consider this feature BETA.
>         *     CAUTION: This is not for hotplugging your peripherals. As
>         *     SCSI was not designed for this you could damage your
>         *     hardware !
>         * However perhaps it is legal to switch on an
>         * already connected device. It is perhaps not
>         * guaranteed this device doesn't corrupt an ongoing data transfer.
>         */
>
>-----Original Message-----
>From: linux-scsi-owner@vger.kernel.org
>[mailto:linux-scsi-owner@vger.kernel.org]On Behalf Of Suresh Kr N
>Sent: Thursday, February 13, 2003 11:01 PM
>To: Steven Dake
>Cc: linux-scsi@vger.kernel.org
>Subject: RE: Adding a new FC disk to a linux host
>
>
>This works for me ( by the way is this still BETA ? i dont see this comment
>in the kernel scsi sources anymore ).
>But then i need to deduce the these input parameters of target no , lun no
>etc , as i need to do this from a userland san management app.
>
>I figured that the HBA apis give you the new target number , and probably i
>could do a report luns or something to get the lun numbers as well. So this
>way could work for me .
>
>Is there a way to ask the midlayer for a full rescan ( so that i wont have
>to find out these parameters )
>
>suresh
>
>
>-----Original Message-----
>From: linux-scsi-owner@vger.kernel.org
>[mailto:linux-scsi-owner@vger.kernel.org]On Behalf Of Steven Dake
>Sent: Thursday, February 13, 2003 5:05 AM
>To: Suresh Kr N
>Cc: linux-scsi@vger.kernel.org
>Subject: Re: Adding a new FC disk to a linux host
>
>
>you can scan specific scsi ids.  read scsi_proc.c search for
>add-single-device
>
>         * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
>         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
>         * Consider this feature BETA.
>
>
>Good luck
>-steve
>
>Suresh Kr N wrote:
>
>  
>
>>sorry about the wrong thread name in the previous post. updated now
>>
>>
>>hi everyone
>>
>>I am working on a san management application for a linux. My application
>>sends zoning commands to the fabric to zone in a disk to a host ,  so i
>>    
>>
>need
>  
>
>>to have that disk acessible to the host without a reboot of the host.
>>
>>I need to do this from the user space. Is there a way to ask the scsi
>>midlayer for a rescan ?
>>In solaris , i invoke a command called "drvconfig" to achieve this.
>>
>>I have seen in the linux-scsi archive that this is kind of possible,  but
>>the discussion didnt seem to state how.
>>I am attaching the above thread here in the mail.
>>
>>I have verified that echo "scsi add-single-device a b c d" >
>>    
>>
>/proc/scsi/scsi
>  
>
>>works fine . But this does involve parameters which cant be found out
>>programmatically.
>>
>>Also a side question here :In a FC world, to get the target number for
>>    
>>
>above
>  
>
>>command , can i find out the current maximum target number of the scsi
>>devices, and increase it by one ? or  does the FC devices have actually a
>>preknown target no , which would be collected by the FC card driver ?
>>
>>Could someone please help ? ( even a "non-standard" way should be good
>>enough" )
>>
>>Thanks
>>Suresh
>>
>>
>>
>>--------------------------------------------------------
>>Message 2 in thread
>>From: Alan Cox (alan@lxorguk.ukuu.org.uk)
>>Subject: Re: Hot plugging a disk in runtime
>>View this article only
>>Newsgroups: mlist.linux.scsi
>>Date: 2002-05-20 05:32:38 PST
>>
>>
>>
>>
>>    
>>
>>>1.. How is it possible to signal SCSI mid-layer (or other layers) of a
>>>presence of a newly hot-plugged disk ?
>>>
>>>
>>>      
>>>
>>aacraid is one example that does this, but via its config tools.
>>
>>
>>
>>    
>>
>>>2.. Can an adapter's device driver trigger SCSI subsystem to scan
>>>channels for new LUNs / Targets ?
>>>
>>>
>>>      
>>>
>>It is designed so user space can do so - so yes
>>
>>
>>
>>    
>>
>>>3.. Is this can be handled in a kernel level ? is there a user space
>>>application that can be triggered to start scanning adapters (obviously
>>>through SCSI subsystem) and registering new LUNs / Targets etc... ?
>>>
>>>
>>>      
>>>
>>echo "scsi-add-single-device a b c d" /proc/scsi/scsi
>>
>>if I remember it right
>>
>>
>>entire thread is at
>>
>>http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=linux.scsi.20020
>>    
>>
>5
>  
>
>>201420.g4KEK3x01892%40localhost.localdomain&rnum=7&prev=/groups%3Fq%3Dhot%2
>>    
>>
>B
>  
>
>>plug%2B%2BSCSI%2Bfibre-channel%2BLinux%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sel
>>    
>>
>m
>  
>
>>%3Dlinux.scsi.200205201420.g4KEK3x01892%2540localhost.localdomain%26rnum%3D
>>    
>>
>7
>  
>
>>-
>>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>>the body of a message to majordomo@vger.kernel.org
>>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>-
>>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>>the body of a message to majordomo@vger.kernel.org
>>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
>>
>>
>>
>>    
>>
>
>-
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>-
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>-
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>
>
>  
>

Re: Adding a new FC disk to a linux host

[Steven Dake]

There is a patch (search sourceforge for scsiras) that will 
automatically issue a rescan on the scsi bus whenever a reset occurs. 
 This won't help for fibrechannel, but you might be able to have your 
driver issue a reset causing the scsi bus to rescan with this modified 
kernel patch.

But I'd stick to just inserting what you know it out there rather then 
rescanning all 255 targets.

Thanks
-steve

Suresh Kr N wrote:

>This works for me ( by the way is this still BETA ? i dont see this comment
>in the kernel scsi sources anymore ).
>But then i need to deduce the these input parameters of target no , lun no
>etc , as i need to do this from a userland san management app.
>
>I figured that the HBA apis give you the new target number , and probably i
>could do a report luns or something to get the lun numbers as well. So this
>way could work for me .
>
>Is there a way to ask the midlayer for a full rescan ( so that i wont have
>to find out these parameters )
>
>suresh
>
>
>-----Original Message-----
>From: linux-scsi-owner@vger.kernel.org
>[mailto:linux-scsi-owner@vger.kernel.org]On Behalf Of Steven Dake
>Sent: Thursday, February 13, 2003 5:05 AM
>To: Suresh Kr N
>Cc: linux-scsi@vger.kernel.org
>Subject: Re: Adding a new FC disk to a linux host
>
>
>you can scan specific scsi ids.  read scsi_proc.c search for
>add-single-device
>
>         * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
>         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
>         * Consider this feature BETA.
>
>
>Good luck
>-steve
>
>Suresh Kr N wrote:
>
>  
>
>>sorry about the wrong thread name in the previous post. updated now
>>
>>
>>hi everyone
>>
>>I am working on a san management application for a linux. My application
>>sends zoning commands to the fabric to zone in a disk to a host ,  so i
>>    
>>
>need
>  
>
>>to have that disk acessible to the host without a reboot of the host.
>>
>>I need to do this from the user space. Is there a way to ask the scsi
>>midlayer for a rescan ?
>>In solaris , i invoke a command called "drvconfig" to achieve this.
>>
>>I have seen in the linux-scsi archive that this is kind of possible,  but
>>the discussion didnt seem to state how.
>>I am attaching the above thread here in the mail.
>>
>>I have verified that echo "scsi add-single-device a b c d" >
>>    
>>
>/proc/scsi/scsi
>  
>
>>works fine . But this does involve parameters which cant be found out
>>programmatically.
>>
>>Also a side question here :In a FC world, to get the target number for
>>    
>>
>above
>  
>
>>command , can i find out the current maximum target number of the scsi
>>devices, and increase it by one ? or  does the FC devices have actually a
>>preknown target no , which would be collected by the FC card driver ?
>>
>>Could someone please help ? ( even a "non-standard" way should be good
>>enough" )
>>
>>Thanks
>>Suresh
>>
>>
>>
>>--------------------------------------------------------
>>Message 2 in thread
>>From: Alan Cox (alan@lxorguk.ukuu.org.uk)
>>Subject: Re: Hot plugging a disk in runtime
>>View this article only
>>Newsgroups: mlist.linux.scsi
>>Date: 2002-05-20 05:32:38 PST
>>
>>
>>
>>
>>    
>>
>>>1.. How is it possible to signal SCSI mid-layer (or other layers) of a
>>>presence of a newly hot-plugged disk ?
>>>
>>>
>>>      
>>>
>>aacraid is one example that does this, but via its config tools.
>>
>>
>>
>>    
>>
>>>2.. Can an adapter's device driver trigger SCSI subsystem to scan
>>>channels for new LUNs / Targets ?
>>>
>>>
>>>      
>>>
>>It is designed so user space can do so - so yes
>>
>>
>>
>>    
>>
>>>3.. Is this can be handled in a kernel level ? is there a user space
>>>application that can be triggered to start scanning adapters (obviously
>>>through SCSI subsystem) and registering new LUNs / Targets etc... ?
>>>
>>>
>>>      
>>>
>>echo "scsi-add-single-device a b c d" /proc/scsi/scsi
>>
>>if I remember it right
>>
>>
>>entire thread is at
>>
>>http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=linux.scsi.20020
>>    
>>
>5
>  
>
>>201420.g4KEK3x01892%40localhost.localdomain&rnum=7&prev=/groups%3Fq%3Dhot%2
>>    
>>
>B
>  
>
>>plug%2B%2BSCSI%2Bfibre-channel%2BLinux%26hl%3Den%26lr%3D%26ie%3DUTF-8%26sel
>>    
>>
>m
>  
>
>>%3Dlinux.scsi.200205201420.g4KEK3x01892%2540localhost.localdomain%26rnum%3D
>>    
>>
>7
>  
>
>>-
>>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>>the body of a message to majordomo@vger.kernel.org
>>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>-
>>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>>the body of a message to majordomo@vger.kernel.org
>>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
>>
>>
>>
>>    
>>
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>
>  
>

RE: Adding a new FC disk to a linux host

[Bryan Henderson]

>         *     CAUTION: This is not for hotplugging your peripherals. As
>         *     SCSI was not designed for this you could damage your
>         *     hardware !
>
>Is this safe in a Fibre channel SAN scenario ? could it corrupt an ongoing
>data tranfer in a fibre channel SAN scenario ?

Fibre channel was definitely designed for hotplugging.  You don't have a
problem here.  The only thing you have to worry about is getting Linux to
admit that there's a device present that wasn't present before.