[PATCH/BUG] mdadm: write behind value does not have endian conversion

[PATCH/BUG] mdadm: write behind value does not have endian conversion

[Paul Clements]

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Neil,

The write behind value does not get converted to/from little endian 
which causes write behind not to work on big endian machines (RUN ARRAY 
fails with invalid argument error):

# mdadm -B /dev/md0 -l1 -n2 --write-behind=256 /dev/sdb10 --write-mostly 
/dev/nbd0 --bitmap=/bitmaps/test5
mdadm: RUN_ARRAY failed: Invalid argument

# tail /var/log/messages
Oct  6 13:14:48 caspian kernel:   daemon sleep: 5s
Oct  6 13:14:48 caspian kernel:      sync size: 1001456 KB
Oct  6 13:14:48 caspian kernel: max write behind: 65536
Oct  6 13:14:48 caspian kernel: md0: failed to create bitmap (-22)


Attached patch for mdadm fixes this.

Thanks,
Paul

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--- mdadm-2.5.1/bitmap.c.orig	Fri Oct  6 13:40:35 2006
+++ mdadm-2.5.1/bitmap.c	Fri Oct  6 13:40:53 2006
@@ -33,6 +33,7 @@ inline void sb_le_to_cpu(bitmap_super_t 
 	sb->chunksize = __le32_to_cpu(sb->chunksize);
 	sb->daemon_sleep = __le32_to_cpu(sb->daemon_sleep);
 	sb->sync_size = __le64_to_cpu(sb->sync_size);
+	sb->write_behind = __le32_to_cpu(sb->sync_size);
 }
 
 inline void sb_cpu_to_le(bitmap_super_t *sb)

Re: [PATCH/BUG] mdadm: write behind value does not have endian conversion

[Paul Clements]

Paul Clements wrote:

> --- mdadm-2.5.1/bitmap.c.orig	Fri Oct  6 13:40:35 2006
> +++ mdadm-2.5.1/bitmap.c	Fri Oct  6 13:40:53 2006
> @@ -33,6 +33,7 @@ inline void sb_le_to_cpu(bitmap_super_t 
>  	sb->chunksize = __le32_to_cpu(sb->chunksize);
>  	sb->daemon_sleep = __le32_to_cpu(sb->daemon_sleep);
>  	sb->sync_size = __le64_to_cpu(sb->sync_size);

> +	sb->write_behind = __le32_to_cpu(sb->sync_size);

Obviously, sync_size should be write_behind in the above line.

Re: [PATCH/BUG] mdadm: write behind value does not have endian conversion

[Neil Brown]

On Friday October 6, paul.clements@steeleye.com wrote:
> Paul Clements wrote:
> 
> > --- mdadm-2.5.1/bitmap.c.orig	Fri Oct  6 13:40:35 2006
> > +++ mdadm-2.5.1/bitmap.c	Fri Oct  6 13:40:53 2006
> > @@ -33,6 +33,7 @@ inline void sb_le_to_cpu(bitmap_super_t 
> >  	sb->chunksize = __le32_to_cpu(sb->chunksize);
> >  	sb->daemon_sleep = __le32_to_cpu(sb->daemon_sleep);
> >  	sb->sync_size = __le64_to_cpu(sb->sync_size);
> 
> > +	sb->write_behind = __le32_to_cpu(sb->sync_size);
> 
> Obviously, sync_size should be write_behind in the above line.

Thanks.  
Applied and push out to git.

NeilBrown