Re: 2.6.23.1: mdadm/raid5 hung/d-state

[BERTRAND Joël <joel.bertrand@systella.fr>]

Dan Williams wrote:
> On Tue, 2007-11-06 at 03:19 -0700, BERTRAND Joël wrote:
> >         Done. Here is obtained ouput :
>
> Much appreciated.
> > [ 1260.969314] handling stripe 7629696, state=0x14 cnt=1, pd_idx=2 ops=0:0:0
> > [ 1260.980606] check 5: state 0x6 toread 0000000000000000 read 0000000000000000 write fffff800ffcffcc0 written 0000000000000000
> > [ 1260.994808] check 4: state 0x6 toread 0000000000000000 read 0000000000000000 write fffff800fdd4e360 written 0000000000000000
> > [ 1261.009325] check 3: state 0x1 toread 0000000000000000 read 0000000000000000 write 0000000000000000 written 0000000000000000
> > [ 1261.244478] check 2: state 0x1 toread 0000000000000000 read 0000000000000000 write 0000000000000000 written 0000000000000000
> > [ 1261.270821] check 1: state 0x6 toread 0000000000000000 read 0000000000000000 write fffff800ff517e40 written 0000000000000000
> > [ 1261.312320] check 0: state 0x6 toread 0000000000000000 read 0000000000000000 write fffff800fd4cae60 written 0000000000000000
> > [ 1261.361030] locked=4 uptodate=2 to_read=0 to_write=4 failed=0 failed_num=0
> > [ 1261.443120] for sector 7629696, rmw=0 rcw=0
> [..]
>
> This looks as if the blocks were prepared to be written out, but were
> never handled in ops_run_biodrain(), so they remain locked forever.  The
> operations flags are all clear which means handle_stripe thinks nothing
> else needs to be done.
>
> The following patch, also attached, cleans up cases where the code looks
> at sh->ops.pending when it should be looking at the consistent
> stack-based snapshot of the operations flags.

	Thanks for this patch. I'm testing it for three hours. I'm rebuilding a 
1.5 TB raid1 array over iSCSI without any trouble.

gershwin:[/usr/scripts] > cat /proc/mdstat
Personalities : [raid1] [raid6] [raid5] [raid4]
md7 : active raid1 sdi1[2] md_d0p1[0]
      1464725632 blocks [2/1] [U_]
      [=>...................]  recovery =  6.7% (99484736/1464725632) 
finish=1450.9min speed=15679K/sec

Without your patch, I never reached 1%... I hope it fix this bug and I 
shall come back when my raid1 volume shall be resynchronized.

	Regards,

	JKB
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