[PATCH md 000 of 2] Introduction

[PATCH md 000 of 2] Introduction

[NeilBrown]

Two patches against 2.6.12-rc2 for md.
(patches apply to 2.6.12-rc2-mm1 with various offsets).

The first closes an extreme small race in md thread deregistration.
This race was actually lost by someone who, due to a different bug
which has since been fixed, has md threads being created and destroyed
at a very high rate.

The second removes a number of MD_BUG calls that that are either
completely pointless, or misleading (i.e. the report a bug when it is
just an unusual condition that is handled correctly).

NeilBrown


 [PATCH md 001 of 2] Close a small race in md thread deregistration
 [PATCH md 002 of 2] Remove a number of misleading calls to MD_BUG

[PATCH md 000 of 2] Introduction

[NeilBrown]

Hi again,
 two more patches for md follow.  Both raid1 related.
 These are happy to sit in the queue for after 2.6.12.

Thanks,
NeilBrown

 [PATCH md 001 of 2] Cause md/raid1 to "repack" working devices when number of drives is changed.
 [PATCH md 002 of 2] Make sure recovery happens when add_new_disk is used for hot_add

[PATCH md 001 of 2] Cause md/raid1 to "repack" working devices when number of drives is changed.

[NeilBrown]

i.e. missing or failed drives are moved to the end of the list.
The means a 3 drive md array with the first drive missing can be shrunk
to a two drive array.  Currently that isn't possible.

Also, the "last_used" device number might be out-of-range after the number
of devices is reduced, so we set it to 0.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>

### Diffstat output
 ./drivers/md/raid1.c |   24 +++++++++++++++++++-----
 1 files changed, 19 insertions(+), 5 deletions(-)

diff ./drivers/md/raid1.c~current~ ./drivers/md/raid1.c
--- ./drivers/md/raid1.c~current~	2005-05-13 14:47:35.000000000 +1000
+++ ./drivers/md/raid1.c	2005-05-13 14:47:44.000000000 +1000
@@ -1485,17 +1485,26 @@ static int raid1_reshape(mddev_t *mddev,
 	 * We allocate a new r1bio_pool if we can.
 	 * Then raise a device barrier and wait until all IO stops.
 	 * Then resize conf->mirrors and swap in the new r1bio pool.
+	 *
+	 * At the same time, we "pack" the devices so that all the missing
+	 * devices have the higher raid_disk numbers.
 	 */
 	mempool_t *newpool, *oldpool;
 	struct pool_info *newpoolinfo;
 	mirror_info_t *newmirrors;
 	conf_t *conf = mddev_to_conf(mddev);
+	int cnt;
 
-	int d;
+	int d, d2;
 
-	for (d= raid_disks; d < conf->raid_disks; d++)
-		if (conf->mirrors[d].rdev)
+	if (raid_disks < conf->raid_disks) {
+		cnt=0;
+		for (d= 0; d < conf->raid_disks; d++)
+			if (conf->mirrors[d].rdev)
+				cnt++;
+		if (cnt > raid_disks)
 			return -EBUSY;
+	}
 
 	newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
 	if (!newpoolinfo)
@@ -1526,8 +1535,12 @@ static int raid1_reshape(mddev_t *mddev,
 	/* ok, everything is stopped */
 	oldpool = conf->r1bio_pool;
 	conf->r1bio_pool = newpool;
-	for (d=0; d < raid_disks && d < conf->raid_disks; d++)
-		newmirrors[d] = conf->mirrors[d];
+
+	for (d=d2=0; d < conf->raid_disks; d++)
+		if (conf->mirrors[d].rdev) {
+			conf->mirrors[d].rdev->raid_disk = d2;
+			newmirrors[d2++].rdev = conf->mirrors[d].rdev;
+		}
 	kfree(conf->mirrors);
 	conf->mirrors = newmirrors;
 	kfree(conf->poolinfo);
@@ -1536,6 +1549,7 @@ static int raid1_reshape(mddev_t *mddev,
 	mddev->degraded += (raid_disks - conf->raid_disks);
 	conf->raid_disks = mddev->raid_disks = raid_disks;
 
+	conf->last_used = 0; /* just make sure it is in-range */
 	spin_lock_irq(&conf->resync_lock);
 	conf->barrier--;
 	spin_unlock_irq(&conf->resync_lock);

[PATCH md 002 of 2] Make sure recovery happens when add_new_disk is used for hot_add

[NeilBrown]

Currently if add_new_disk is used to hot-add a drive to a degraded
array, recovery doesn't start ... because we didn't tell it to.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>

### Diffstat output
 ./drivers/md/md.c |    2 ++
 1 files changed, 2 insertions(+)

diff ./drivers/md/md.c~current~ ./drivers/md/md.c
--- ./drivers/md/md.c~current~	2005-05-13 14:47:35.000000000 +1000
+++ ./drivers/md/md.c	2005-05-13 14:48:22.000000000 +1000
@@ -2232,6 +2232,8 @@ static int add_new_disk(mddev_t * mddev,
 		err = bind_rdev_to_array(rdev, mddev);
 		if (err)
 			export_rdev(rdev);
+
+		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 		if (mddev->thread)
 			md_wakeup_thread(mddev->thread);
 		return err;

[PATCH 1/1] md: fix hot add for non-persistent superblock arrays

[Paul Clements]

[-- Attachment #1: Type: text/plain, Size: 181 bytes --]

Neil,

hot add is not working for non-persistent superblock arrays (md is 
trying, and failing, to read a superblock from the new disk)...

attached patch fixes it...

Thanks,
Paul

[-- Attachment #2: md_non_persistent_hot_add.diff --]
[-- Type: text/plain, Size: 742 bytes --]


Signed-Off-By: Paul Clements <paul.clements@steeleye.com>

 md.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletion(-)
diff -purN --exclude-from /export/public/clemep/tmp/dontdiff linux-2.6.12-rc1-mm2-PRISTINE/drivers/md/md.c linux-2.6.12-rc1-mm2/drivers/md/md.c
--- linux-2.6.12-rc1-mm2-PRISTINE/drivers/md/md.c	Fri Mar 25 14:33:36 2005
+++ linux-2.6.12-rc1-mm2/drivers/md/md.c	Thu May 19 16:29:44 2005
@@ -2218,7 +2218,8 @@ static int add_new_disk(mddev_t * mddev,
 			       mdname(mddev));
 			return -EINVAL;
 		}
-		rdev = md_import_device(dev, mddev->major_version,
+		rdev = md_import_device(dev, mddev->persistent ?
+					mddev->major_version : -1,
 					mddev->minor_version);
 		if (IS_ERR(rdev)) {
 			printk(KERN_WARNING 

Re: [PATCH 1/1] md: fix hot add for non-persistent superblock arrays

[Neil Brown]

On Thursday May 19, paul.clements@steeleye.com wrote:
> Neil,
> 
> hot add is not working for non-persistent superblock arrays (md is 
> trying, and failing, to read a superblock from the new disk)...
> 
> attached patch fixes it...

Yep, that looks good, thanks.

NeilBrown

> 
> Thanks,
> Paul
> 
> Signed-Off-By: Paul Clements <paul.clements@steeleye.com>
> 
>  md.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletion(-)
> diff -purN --exclude-from /export/public/clemep/tmp/dontdiff linux-2.6.12-rc1-mm2-PRISTINE/drivers/md/md.c linux-2.6.12-rc1-mm2/drivers/md/md.c
> --- linux-2.6.12-rc1-mm2-PRISTINE/drivers/md/md.c	Fri Mar 25 14:33:36 2005
> +++ linux-2.6.12-rc1-mm2/drivers/md/md.c	Thu May 19 16:29:44 2005
> @@ -2218,7 +2218,8 @@ static int add_new_disk(mddev_t * mddev,
>  			       mdname(mddev));
>  			return -EINVAL;
>  		}
> -		rdev = md_import_device(dev, mddev->major_version,
> +		rdev = md_import_device(dev, mddev->persistent ?
> +					mddev->major_version : -1,
>  					mddev->minor_version);
>  		if (IS_ERR(rdev)) {
>  			printk(KERN_WARNING 

[PATCH md 000 of 2] Introduction

[NeilBrown]

Following are two very trivial patches against 2.6.13-rc6.
If 2.6.13 is still open for such trivial fixes, it would be good for
them to go in, but if not, I won't loose any sleep over it.

The first arranges that the first open of /dev/mdX will auto-load the
md modules (I don't know when that functionality disappeared).
The second fixes a possibly problem where-by if you stop an array and
create a new one on the same md device, it might not start any resync
that might be needed.

Thanks,
NeilBrown


 [PATCH md 001 of 2] Create a MODULE_ALIAS for md corresponding to it's block major number.
 [PATCH md 002 of 2] Clear the 'recovery' flags when starting an md array.

[PATCH md 000 of 2] Introduction

[NeilBrown]

Two patches for md in 2.6.14-rc5-mm1 (First one depends on -mm stuff,
second should apply to most recent 2.6 kernels).

I'd like to review the sysfs a bit more before it goes to Linus, but
the rest can go anytime.
Thanks,
NeilBrown


 [PATCH md 001 of 2] Remove attempt to use dynamic names in sysfs for component devices on an MD array.
 [PATCH md 002 of 2] Allow md arrays to be started read-only (module parameter).

Re: [PATCH md 000 of 2] Introduction

[Neil Brown]

On Sunday October 30, akpm@osdl.org wrote:
> NeilBrown <neilb@suse.de> wrote:
> >
> > 
> >  I'd like to review the sysfs a bit more before it goes to Linus, but
> >  the rest can go anytime.
> 
> umm, what does "the sysfs" refer to?

Sorry.. "the sysfs related patches".

Those marked as 'THIS' below.  

However I think a couple that come after those won't simple move
backwards (largely due to
md-convert-faulty-and-in_sync-fields-to-bits-in-flags-field).

I'll make sure you have a full set that I am happy to go to Linus by
the end of the week.

Thanks,
NeilBrown


> 
> Current md patches in -mm:
> 
> md-better-handling-of-readerrors-with-raid5.patch
THIS > md-initial-sysfs-support-for-md.patch
THIS > md-extend-md-sysfs-support-to-component-devices.patch
THIS > md-add-kobject-sysfs-support-to-raid5.patch
THIS > md-allow-a-manual-resync-with-md.patch
THIS > md-teach-raid5-the-difference-between-check-and-repair.patch
> md-provide-proper-rcu_dereference--rcu_assign_pointer-annotations-in-md.patch
THIS > md-fix-ref-counting-problems-with-kobjects-in-md.patch
THIS > md-minor-md-fixes.patch
THIS > md-change-raid5-sysfs-attribute-to-not-create-a-new-directory.patch
> md-improvements-to-raid5-handling-of-read-errors.patch
> md-convert-faulty-and-in_sync-fields-to-bits-in-flags-field.patch
> md-make-md-on-disk-bitmaps-not-host-endian.patch
> md-support-bio_rw_barrier-for-md-raid1.patch
> drivers-md-fix-up-schedule_timeout-usage.patch
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH md 000 of 2] Introduction

[Andrew Morton]

NeilBrown <neilb@suse.de> wrote:
>
> 
>  I'd like to review the sysfs a bit more before it goes to Linus, but
>  the rest can go anytime.

umm, what does "the sysfs" refer to?

Current md patches in -mm:

md-better-handling-of-readerrors-with-raid5.patch
md-initial-sysfs-support-for-md.patch
md-extend-md-sysfs-support-to-component-devices.patch
md-add-kobject-sysfs-support-to-raid5.patch
md-allow-a-manual-resync-with-md.patch
md-teach-raid5-the-difference-between-check-and-repair.patch
md-provide-proper-rcu_dereference--rcu_assign_pointer-annotations-in-md.patch
md-fix-ref-counting-problems-with-kobjects-in-md.patch
md-minor-md-fixes.patch
md-change-raid5-sysfs-attribute-to-not-create-a-new-directory.patch
md-improvements-to-raid5-handling-of-read-errors.patch
md-convert-faulty-and-in_sync-fields-to-bits-in-flags-field.patch
md-make-md-on-disk-bitmaps-not-host-endian.patch
md-support-bio_rw_barrier-for-md-raid1.patch
drivers-md-fix-up-schedule_timeout-usage.patch

Re: [PATCH md 000 of 2] Introduction

[Andrew Morton]

Neil Brown <neilb@suse.de> wrote:
>
> On Sunday October 30, akpm@osdl.org wrote:
> > NeilBrown <neilb@suse.de> wrote:
> > >
> > > 
> > >  I'd like to review the sysfs a bit more before it goes to Linus, but
> > >  the rest can go anytime.
> > 
> > umm, what does "the sysfs" refer to?
> 
> Sorry.. "the sysfs related patches".
> 
> Those marked as 'THIS' below.  
> 
> However I think a couple that come after those won't simple move
> backwards (largely due to
> md-convert-faulty-and-in_sync-fields-to-bits-in-flags-field).
> 
> I'll make sure you have a full set that I am happy to go to Linus by
> the end of the week.

hm, OK, that's a bit late in the process to be introducing new material, so
no later please.

Also, please make sure that Greg is copied on sysfs things - save me an
email ;)

Re: [PATCH md 000 of 2] Introduction

[Mr. James W. Laferriere]

	Hello Neil ,  The original '[PATCH md 000 of 2] Introduction' never hit 
	the list afaict .  Could you please re-send or if you did & only I am 
	without it send privately .  Tia ,  JimL

On Mon, 31 Oct 2005, Neil Brown wrote:
> On Sunday October 30, akpm@osdl.org wrote:
> > NeilBrown <neilb@suse.de> wrote:
> > >  I'd like to review the sysfs a bit more before it goes to Linus, but
> > >  the rest can go anytime.
> > umm, what does "the sysfs" refer to?
> Sorry.. "the sysfs related patches".
> Those marked as 'THIS' below.  
> However I think a couple that come after those won't simple move
> backwards (largely due to
> md-convert-faulty-and-in_sync-fields-to-bits-in-flags-field).
> I'll make sure you have a full set that I am happy to go to Linus by
> the end of the week.
> Thanks,
> NeilBrown
> > Current md patches in -mm:
> > md-better-handling-of-readerrors-with-raid5.patch
> THIS > md-initial-sysfs-support-for-md.patch
> THIS > md-extend-md-sysfs-support-to-component-devices.patch
> THIS > md-add-kobject-sysfs-support-to-raid5.patch
> THIS > md-allow-a-manual-resync-with-md.patch
> THIS > md-teach-raid5-the-difference-between-check-and-repair.patch
> > md-provide-proper-rcu_dereference--rcu_assign_pointer-annotations-in-md.patch
> THIS > md-fix-ref-counting-problems-with-kobjects-in-md.patch
> THIS > md-minor-md-fixes.patch
> THIS > md-change-raid5-sysfs-attribute-to-not-create-a-new-directory.patch
> > md-improvements-to-raid5-handling-of-read-errors.patch
> > md-convert-faulty-and-in_sync-fields-to-bits-in-flags-field.patch
> > md-make-md-on-disk-bitmaps-not-host-endian.patch
> > md-support-bio_rw_barrier-for-md-raid1.patch
> > drivers-md-fix-up-schedule_timeout-usage.patch
-- 
+------------------------------------------------------------------+
| James   W.   Laferriere | System    Techniques | Give me VMS     |
| Network        Engineer | 3542 Broken Yoke Dr. |  Give me Linux  |
| babydr@baby-dragons.com | Billings , MT. 59105 |   only  on  AXP |
+------------------------------------------------------------------+

Re: [PATCH md 000 of 2] Introduction

[Neil Brown]

On Monday October 31, babydr@baby-dragons.com wrote:
> 	Hello Neil ,  The original '[PATCH md 000 of 2] Introduction' never hit 
> 	the list afaict .  Could you please re-send or if you did & only I am 
> 	without it send privately .  Tia ,  JimL

I cannot knot who else is without it :-), but you can find it here.


http://marc.theaimsgroup.com/?l=linux-raid&m=113073839213484&w=2


NeilBrown

[PATCH md 000 of 2] Introduction

[NeilBrown]

Following are two patches for md in 2.6.14-mm2 that are suitable to go
into the 2.6.15-rc series.

The first adds a date to the deprecation of START_ARRAY ioctl.

The second fixes a recently introduced problem that causes md threads
to permanently add to the load average (other than that, every works
fine).

 [PATCH md 001 of 2] Mark START_ARRAY deprecated with a date.
 [PATCH md 002 of 2] Make md threads interruptible again.

Re: [PATCH md 000 of 2] Introduction

[Mr. James W. Laferriere]

 	Hello Neil ,

On Tue, 15 Nov 2005, NeilBrown wrote:
> Following are two patches for md in 2.6.14-mm2 that are suitable to go
> into the 2.6.15-rc series.
>
> The first adds a date to the deprecation of START_ARRAY ioctl.
>
> The second fixes a recently introduced problem that causes md threads
> to permanently add to the load average (other than that, every works
> fine).
>
> [PATCH md 001 of 2] Mark START_ARRAY deprecated with a date.
> [PATCH md 002 of 2] Make md threads interruptible again.

> diff ./Documentation/feature-removal-schedule.txt~current~ /Documentation/feature-removal-schedule.txt
> --- ./Documentation/feature-removal-schedule.txt~current~       2005-11-15 10:25:30.000000000 +1100
> +++ ./Documentation/feature-removal-schedule.txt        2005-11-15 10:25:30.000000000 +1100
> @@ -131,3 +131,12 @@ What:      EXPORT_SYMBOL(lookup_hash)
>  When:  January 2006
>  Why:   Too low-level interface.  Use lookup_one_len or lookup_create instead.
>  Who:   Christoph Hellwig <hch@lst.de>
> +
> +---------------------------
> +
> +What:  START_ARRAY ioctl for md
> +When:  July 2006
> +Files: drivers/md/md.c
> +Why:   Not reliable by design - can fail when most needed.
> +       Alternatives exist
> +Who:   NeilBrown <neilb@suse.de>

 	Would some please update Documentation/md.txt with the alternates
 	that exist to replace START_ARRAY ?  Or for that matter any kernel
 	related document that covers the md driver &/or its tools .
 		Tia ,  JimL

-- 
+------------------------------------------------------------------+
| James   W.   Laferriere | System    Techniques | Give me VMS     |
| Network        Engineer | 3542 Broken Yoke Dr. |  Give me Linux  |
| babydr@baby-dragons.com | Billings , MT. 59105 |   only  on  AXP |
+------------------------------------------------------------------+

Re: [PATCH md 000 of 2] Introduction

[Neil Brown]

On Tuesday November 15, babydr@baby-dragons.com wrote:
>  	Hello Neil ,
> 
> On Tue, 15 Nov 2005, NeilBrown wrote:
> > +
> > +---------------------------
> > +
> > +What:  START_ARRAY ioctl for md
> > +When:  July 2006
> > +Files: drivers/md/md.c
> > +Why:   Not reliable by design - can fail when most needed.
> > +       Alternatives exist
> > +Who:   NeilBrown <neilb@suse.de>
> 
>  	Would some please update Documentation/md.txt with the alternates
>  	that exist to replace START_ARRAY ?  Or for that matter any kernel
>  	related document that covers the md driver &/or its tools .
>  		Tia ,  JimL
> 

Are you just asking "What are the 'Alternatives' that are claimed to
exist?"?
If so, then it is  'mdadm -A'.  I guess I could make that more
explicit.

Or are you asking something else?

NeilBrown

Re: [PATCH md 000 of 2] Introduction

[Mr. James W. Laferriere]

  	Hello Neil ,

On Thu, 17 Nov 2005, Neil Brown wrote:
> On Tuesday November 15, babydr@baby-dragons.com wrote:
>> On Tue, 15 Nov 2005, NeilBrown wrote:
>>> +
>>> +---------------------------
>>> +
>>> +What:  START_ARRAY ioctl for md
>>> +When:  July 2006
>>> +Files: drivers/md/md.c
>>> +Why:   Not reliable by design - can fail when most needed.
>>> +       Alternatives exist
>>> +Who:   NeilBrown <neilb@suse.de>
>>
>>  	Would some please update Documentation/md.txt with the alternates
>>  	that exist to replace START_ARRAY ?  Or for that matter any kernel
>>  	related document that covers the md driver &/or its tools .
>>  		Tia ,  JimL
> Are you just asking "What are the 'Alternatives' that are claimed to
> exist?"?
 	Yes ,  And to have them documented .

> If so, then it is  'mdadm -A'.  I guess I could make that more
> explicit.
 	Hmm ,  Where is mdadm documented as linux-raid tool(set) IN the
 	kernel tree ?  It's not in md.txt ..
# grep mdadm /usr/src/linux/Documentation/md.txt
#
 	Please help me(us) here .

> Or are you asking something else?
 	No ,  You got it right .  Tia ,  JimL
-- 
+------------------------------------------------------------------+
| James   W.   Laferriere | System    Techniques | Give me VMS     |
| Network        Engineer | 3542 Broken Yoke Dr. |  Give me Linux  |
| babydr@baby-dragons.com | Billings , MT. 59105 |   only  on  AXP |
+------------------------------------------------------------------+

[PATCH md 000 of 2] Introduction

[NeilBrown]

Following are two patches for md in 2.6.15-rc what should get into
2.6.15-final if possible.

The first refines a newly created interface (/sys/block/mdX/md/level).
I've decided that 'raid5' is better than 'RAID-5' after all.

The second removes some limits that shouldn't really be imposed in the kernel.

Thanks,
NeilBrown



 [PATCH md 001 of 2] Change case of raid level reported in sys/mdX/md/level
 [PATCH md 002 of 2] Remove inappropriate limits in md/bitmap configuration.