Re: ZRAM 3.10.6 Buffer I/O error

[Thomas Backlund <tmb@mageia.org>]

12.08.2013 17:27, Jordi Pujol skrev:
> Hello,
>
> zram shows an error when mounting a swap partition,
> current version Linux kernel 3.10.6,
> previous versions worked, I suppose that latest zram patches have some
> problem,
>
> machine is an AMD64 dual core, 4GB RAM
>
> + modprobe -qb zram num_devices=2
> + echo 104857600 > /sys/block/zram0/disksize
>
> # mkswap /dev/zram0
> Setting up swapspace version 1, size = 102396 KiB
> no label, UUID=6c249930-2ba0-46cf-a8c6-766481942b7d
>
> # pager /var/log/dmesg
> (no more errors shown)
>
> # swapon /dev/zram0
>
> # pager /var/log/dmesg
> ...
> [  309.300479] Buffer I/O error on device zram0, logical block 25599
> [  309.300491] Buffer I/O error on device zram0, logical block 25599
> [  309.300514] Buffer I/O error on device zram0, logical block 25599
> [  345.205887] Adding 102396k swap on /dev/zram0.  Priority:-2 extents:1
> across:102396k SSFS
>
> full log files and the kernel source are stored in the address:
>
> http://livenet.selfip.com/ftp/debian/zram_3.10.6_IO_error/
>


I think this one should fix it and belongs in 3.10 stable too:

 From 75c7caf5a052ffd8db3312fa7864ee2d142890c4 Mon Sep 17 00:00:00 2001
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Date: Sat, 22 Jun 2013 14:21:00 +0000
Subject: zram: allow request end to coincide with disksize

Pass valid_io_request() checks if request end coincides with disksize
(end equals bound), only fail if we attempt to read beyond the bound.

mkfs.ext2 produces numerous errors:
[ 2164.632747] quiet_error: 1 callbacks suppressed
[ 2164.633260] Buffer I/O error on device zram0, logical block 153599
[ 2164.633265] lost page write due to I/O error on zram0

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
diff --git a/drivers/staging/zram/zram_drv.c 
b/drivers/staging/zram/zram_drv.c
index 7538774..82c7202 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -180,7 +180,7 @@ static inline int valid_io_request(struct zram 
*zram, struct bio *bio)
  	end = start + (bio->bi_size >> SECTOR_SHIFT);
  	bound = zram->disksize >> SECTOR_SHIFT;
  	/* out of range range */
-	if (unlikely(start >= bound || end >= bound || start > end))
+	if (unlikely(start >= bound || end > bound || start > end))
  		return 0;

  	/* I/O request is valid */
--
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