[PATCH] bug fix for the ntfs driver

[PATCH] bug fix for the ntfs driver

[Bean]

Hi,

This patch fix a bug in the ntfs driver which occurs when accessing
certain compressed files.

-- 
Bean

2007-08-16  Bean  <bean123ch@gmail.com>

	* fs/ntfs.c (read_block): Bug fix for compressed files.


Index: fs/ntfs.c
===================================================================
RCS file: /sources/grub/grub2/fs/ntfs.c,v
retrieving revision 1.1
diff -u -p -r1.1 ntfs.c
--- fs/ntfs.c	3 Aug 2007 07:44:01 -0000	1.1
+++ fs/ntfs.c	15 Aug 2007 16:15:48 -0000
@@ -665,9 +665,6 @@ read_block (struct grub_ntfs_rlst *ctx,
 	      if (read_run_list (ctx))
 		return grub_errno;
 	    }
-	  if (ctx->target_vcn + 16 < ctx->next_vcn)
-	    return grub_error (GRUB_ERR_BAD_FS,
-			       "Compression block should be 16 sector long");
 	}

       nn = (16 - (ctx->target_vcn & 0xF)) / cpb;
@@ -732,7 +729,9 @@ read_block (struct grub_ntfs_rlst *ctx,
 	      if (buf)
 		{
 		  if (grub_disk_read
-		      (ctx->comp.disk, ctx->curr_lcn * ctx->comp.spc, 0,
+		      (ctx->comp.disk,
+		       (ctx->target_vcn - ctx->curr_vcn +
+			ctx->curr_lcn) * ctx->comp.spc, 0,
 		       nn * (ctx->comp.spc << BLK_SHR), buf))
 		    return grub_errno;
 		  buf += nn * (ctx->comp.spc << BLK_SHR);

Re: [PATCH] bug fix for the ntfs driver

[Marco Gerards]

Bean <bean123ch@gmail.com> writes:

Hi Bean,

> This patch fix a bug in the ntfs driver which occurs when accessing
> certain compressed files.

Sorry again for the late reply...

> 2007-08-16  Bean  <bean123ch@gmail.com>
>
> 	* fs/ntfs.c (read_block): Bug fix for compressed files.

Please describe in the changelog entry what changed, not the
functional effect.  Examples can be:

- Fix off-by-one error.
- Initialize variable to 9.
- Check if memory allocation fails, in that case return an error.

etc.

Unfortunately I do not understand your change, why it is required and
what the error was.  Can you please update the changelog entry?

Thanks,
Marco

Re: [PATCH] bug fix for the ntfs driver

[Bean]

Hi,

The problem is caused by the structure of compressed files. In ntfs,
16 clusters is the basic compressed unit. The original code assume
that the file will break in 16 cluster long blocks, but in fact, the
blocks will be merged if they are stored next to to each other on
disk. The new code fix this problem.

       * fs/ntfs.c (read_block): Fix a bug caused by adjacent blocks.

On 8/20/07, Marco Gerards <mgerards@xs4all.nl> wrote:
> Bean <bean123ch@gmail.com> writes:
>
> Hi Bean,
>
> > This patch fix a bug in the ntfs driver which occurs when accessing
> > certain compressed files.
>
> Sorry again for the late reply...
>
> > 2007-08-16  Bean  <bean123ch@gmail.com>
> >
> >       * fs/ntfs.c (read_block): Bug fix for compressed files.
>
> Please describe in the changelog entry what changed, not the
> functional effect.  Examples can be:
>
> - Fix off-by-one error.
> - Initialize variable to 9.
> - Check if memory allocation fails, in that case return an error.
>
> etc.
>
> Unfortunately I do not understand your change, why it is required and
> what the error was.  Can you please update the changelog entry?
>
> Thanks,
> Marco
>
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>


-- 
Bean

Re: [PATCH] bug fix for the ntfs driver

[Marco Gerards]

Bean <bean123ch@gmail.com> writes:

Hi,

> The problem is caused by the structure of compressed files. In ntfs,
> 16 clusters is the basic compressed unit. The original code assume
> that the file will break in 16 cluster long blocks, but in fact, the
> blocks will be merged if they are stored next to to each other on
> disk. The new code fix this problem.
>
>        * fs/ntfs.c (read_block): Fix a bug caused by adjacent blocks.

Sorry for forgetting about this patch.  It should be committed.

Robert, if you have time, can you commit this?  I will mark this mail
as important... If you don't have the time, I will surely commit it
ASAP :-)

--
Marco

Re: [PATCH] bug fix for the ntfs driver

[Robert Millan]

On Sat, Nov 10, 2007 at 06:31:09PM +0100, Marco Gerards wrote:
> 
> Sorry for forgetting about this patch.  It should be committed.
> 
> Robert, if you have time, can you commit this?  I will mark this mail
> as important... If you don't have the time, I will surely commit it
> ASAP :-)

Done.

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What use is a phone call, if you are unable to speak?
(as seen on /.)