[PATCH] FIX: chunk_size cannot be read by mdstat

[PATCH] FIX: chunk_size cannot be read by mdstat

[Adam Kwolek]

Chunk size is not read by mdstat due to too week checking of 'check' string in mdstat.
It is the same result for 'check' and 'chunk_size' check.

Add  string length additional condition for checking.

Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
---

 mdstat.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/mdstat.c b/mdstat.c
index bb030bf..5f69e31 100644
--- a/mdstat.c
+++ b/mdstat.c
@@ -248,7 +248,8 @@ struct mdstat_ent *mdstat_read(int hold, int start)
 				else
 					ent->resync = 0;
 			} else if (ent->percent == -1 &&
-				   (w[0] == 'r' || w[0] == 'c')) {
+				   (w[0] == 'r' ||
+				    ((w[0] == 'c') && strlen(w) < 9))) {
 				if (strncmp(w, "resync", 4)==0)
 					ent->resync = 1;
 				if (strncmp(w, "reshape", 7)==0)

RE: [PATCH] FIX: chunk_size cannot be read by mdstat

[Kwolek, Adam]

I've found that condition on strlen() doesn't always work (I wanted to achieve the same code style ;)),
so check for "check" string has to be used instead.

BR
Adam


> -----Original Message-----
> From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
> owner@vger.kernel.org] On Behalf Of Adam Kwolek
> Sent: Monday, November 29, 2010 10:57 AM
> To: neilb@suse.de
> Cc: linux-raid@vger.kernel.org; Williams, Dan J; Ciechanowski, Ed
> Subject: [PATCH] FIX: chunk_size cannot be read by mdstat
> 
> Chunk size is not read by mdstat due to too week checking of 'check'
> string in mdstat.
> It is the same result for 'check' and 'chunk_size' check.
> 
> Add  string length additional condition for checking.
> 
> Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
> ---
> 
>  mdstat.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/mdstat.c b/mdstat.c
> index bb030bf..5f69e31 100644
> --- a/mdstat.c
> +++ b/mdstat.c
> @@ -248,7 +248,8 @@ struct mdstat_ent *mdstat_read(int hold, int start)
>  				else
>  					ent->resync = 0;
>  			} else if (ent->percent == -1 &&
> -				   (w[0] == 'r' || w[0] == 'c')) {
> +				   (w[0] == 'r' ||
> +				    ((w[0] == 'c') && strlen(w) < 9))) {
>  				if (strncmp(w, "resync", 4)==0)
>  					ent->resync = 1;
>  				if (strncmp(w, "reshape", 7)==0)
> 
> --
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Re: [PATCH] FIX: chunk_size cannot be read by mdstat

[Neil Brown]

On Mon, 29 Nov 2010 10:56:50 +0100 Adam Kwolek <adam.kwolek@intel.com> wrote:

> Chunk size is not read by mdstat due to too week checking of 'check' string in mdstat.
> It is the same result for 'check' and 'chunk_size' check.

Actually chunk size is not read because there is no code to try to read it.
The chunk size needs to be reported by the personality, and they are
inconsistent in the way they report it so it is much easier to just ignore it.
GET_ARRAY_INFO gets the chunk size easily, so we stick with that when chunk
size is needed.

Thanks,
NeilBrown



> 
> Add  string length additional condition for checking.
> 
> Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
> ---
> 
>  mdstat.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/mdstat.c b/mdstat.c
> index bb030bf..5f69e31 100644
> --- a/mdstat.c
> +++ b/mdstat.c
> @@ -248,7 +248,8 @@ struct mdstat_ent *mdstat_read(int hold, int start)
>  				else
>  					ent->resync = 0;
>  			} else if (ent->percent == -1 &&
> -				   (w[0] == 'r' || w[0] == 'c')) {
> +				   (w[0] == 'r' ||
> +				    ((w[0] == 'c') && strlen(w) < 9))) {
>  				if (strncmp(w, "resync", 4)==0)
>  					ent->resync = 1;
>  				if (strncmp(w, "reshape", 7)==0)

RE: [PATCH] FIX: chunk_size cannot be read by mdstat

[Kwolek, Adam]

In such case code: 
	a->info.array.chunk_size = mdstat->chunk_size;

from managemon.c, function manage_member() 
has to be removed or guarded for 0 value of mdstat->chunk_size as it corrupts information in active array.

BR
Adam




> -----Original Message-----
> From: Neil Brown [mailto:neilb@suse.de]
> Sent: Tuesday, November 30, 2010 1:22 AM
> To: Kwolek, Adam
> Cc: linux-raid@vger.kernel.org; Williams, Dan J; Ciechanowski, Ed
> Subject: Re: [PATCH] FIX: chunk_size cannot be read by mdstat
> 
> On Mon, 29 Nov 2010 10:56:50 +0100 Adam Kwolek <adam.kwolek@intel.com>
> wrote:
> 
> > Chunk size is not read by mdstat due to too week checking of 'check'
> string in mdstat.
> > It is the same result for 'check' and 'chunk_size' check.
> 
> Actually chunk size is not read because there is no code to try to read
> it.
> The chunk size needs to be reported by the personality, and they are
> inconsistent in the way they report it so it is much easier to just
> ignore it.
> GET_ARRAY_INFO gets the chunk size easily, so we stick with that when
> chunk
> size is needed.
> 
> Thanks,
> NeilBrown
> 
> 
> 
> >
> > Add  string length additional condition for checking.
> >
> > Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
> > ---
> >
> >  mdstat.c |    3 ++-
> >  1 files changed, 2 insertions(+), 1 deletions(-)
> >
> > diff --git a/mdstat.c b/mdstat.c
> > index bb030bf..5f69e31 100644
> > --- a/mdstat.c
> > +++ b/mdstat.c
> > @@ -248,7 +248,8 @@ struct mdstat_ent *mdstat_read(int hold, int
> start)
> >  				else
> >  					ent->resync = 0;
> >  			} else if (ent->percent == -1 &&
> > -				   (w[0] == 'r' || w[0] == 'c')) {
> > +				   (w[0] == 'r' ||
> > +				    ((w[0] == 'c') && strlen(w) < 9))) {
> >  				if (strncmp(w, "resync", 4)==0)
> >  					ent->resync = 1;
> >  				if (strncmp(w, "reshape", 7)==0)

Re: [PATCH] FIX: chunk_size cannot be read by mdstat

[Neil Brown]

On Tue, 30 Nov 2010 07:28:01 +0000 "Kwolek, Adam" <adam.kwolek@intel.com>
wrote:

> In such case code: 
> 	a->info.array.chunk_size = mdstat->chunk_size;
> 
> from managemon.c, function manage_member() 
> has to be removed or guarded for 0 value of mdstat->chunk_size as it corrupts information in active array.
> 

Good point.  I have removed that assignment, and removed the chunk_size field
from mdstat_ent.

Thanks,
NeilBrown