Re: Problem with raid1 read error patch

[Martin Josefsson <gandalf@wlug.westbo.se>]

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On Mon, 2004-09-20 at 18:14, Martin Josefsson wrote:

Hi Paul

> > I've been debugging the same problem just recently. In addition to this 
> > patch from Neil, you'll also need a patch that I posted here last week, 
> > which does a bio_put() and a bio_clone() to get rid of the old bio that 
> > the read error occurred on, and create a new (clean) bio to retry the 
> > read against:
> > 
> > http://marc.theaimsgroup.com/?l=linux-raid&m=109527014728404&w=2
> 
> Thanks, will try it out tomorrow when I'm back in front of the machine.
> Didn't expect an answer so soon :)

I tested the patch today, worked like a charm. Thank you.

There's been some small changes in 2.6.9-rc2-bk6 which is the kernel
I've been testing with. I applied your fix by hand and diffed, the
resulting patch is attached to make life easy for others with the same
problem.

Thanks again.

-- 
/Martin

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--- linux-2.6.9-rc2-bk6/drivers/md/raid1.c.nofix	2004-09-21 09:25:48.000000000 +0200
+++ linux-2.6.9-rc2-bk6/drivers/md/raid1.c	2004-09-21 09:27:56.000000000 +0200
@@ -941,6 +941,9 @@
 			} else {
 				r1_bio->bios[r1_bio->read_disk] = NULL;
 				r1_bio->read_disk = disk;
+				/* discard the failed bio and clone a new one */
+				bio_put(bio);
+				bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
 				r1_bio->bios[r1_bio->read_disk] = bio;
 				rdev = conf->mirrors[disk].rdev;
 				if (printk_ratelimit())
@@ -948,9 +951,11 @@
 					       " another mirror\n",
 					       bdevname(rdev->bdev,b),
 					       (unsigned long long)r1_bio->sector);
-				bio->bi_bdev = rdev->bdev;
 				bio->bi_sector = r1_bio->sector + rdev->data_offset;
+				bio->bi_bdev = rdev->bdev;
+				bio->bi_end_io = raid1_end_read_request;
 				bio->bi_rw = READ;
+				bio->bi_private = r1_bio;
 				unplug = 1;
 				generic_make_request(bio);
 			}

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