[PATCH] fix remount rw with unrecognized options

[PATCH] fix remount rw with unrecognized options

[Christoph Hellwig]

When we skip unrecognized options in xfs_fs_remount we should just break
out of the switch and not return because otherwise we may skip clearing
the xfs-internal read-only flag.  This will only show up on some
operations like touch because most read-only checks are done by the VFS
which things this filesystem is r/w.  Eventually we should replace the
XFS read-only flag with a helper that always checks the VFS flag to make
sure they can never get out of sync.

Bug reported and fix verified by Marcel Beister on #xfs.


Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_super.c
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_super.c	2008-10-11 00:59:04.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_super.c	2008-10-11 00:59:35.000000000 +0200
@@ -1218,7 +1218,7 @@ xfs_fs_remount(
 	"XFS: mount option \"%s\" not supported for remount\n", p);
 			return -EINVAL;
 #else
-			return 0;
+			break;
 #endif
 		}
 	}

Re: [PATCH] fix remount rw with unrecognized options

[Eric Sandeen]

Christoph Hellwig wrote:
> When we skip unrecognized options in xfs_fs_remount we should just break
> out of the switch and not return because otherwise we may skip clearing
> the xfs-internal read-only flag.  This will only show up on some
> operations like touch because most read-only checks are done by the VFS
> which things this filesystem is r/w.  Eventually we should replace the
> XFS read-only flag with a helper that always checks the VFS flag to make
> sure they can never get out of sync.
> 
> Bug reported and fix verified by Marcel Beister on #xfs.

Seems reasonable.

I think this is 2.6.27.1 material?

-Eric

> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_super.c
> ===================================================================
> --- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_super.c	2008-10-11 00:59:04.000000000 +0200
> +++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_super.c	2008-10-11 00:59:35.000000000 +0200
> @@ -1218,7 +1218,7 @@ xfs_fs_remount(
>  	"XFS: mount option \"%s\" not supported for remount\n", p);
>  			return -EINVAL;
>  #else
> -			return 0;
> +			break;
>  #endif
>  		}
>  	}
> 
> 

Re: [PATCH] fix remount rw with unrecognized options

[Christoph Hellwig]

On Sun, Oct 12, 2008 at 05:19:51PM -0500, Eric Sandeen wrote:
> Christoph Hellwig wrote:
> > When we skip unrecognized options in xfs_fs_remount we should just break
> > out of the switch and not return because otherwise we may skip clearing
> > the xfs-internal read-only flag.  This will only show up on some
> > operations like touch because most read-only checks are done by the VFS
> > which things this filesystem is r/w.  Eventually we should replace the
> > XFS read-only flag with a helper that always checks the VFS flag to make
> > sure they can never get out of sync.
> > 
> > Bug reported and fix verified by Marcel Beister on #xfs.
> 
> Seems reasonable.
> 
> I think this is 2.6.27.1 material?

Yes.

Re: [PATCH] fix remount rw with unrecognized options

[Eric Sandeen]

Christoph Hellwig wrote:
> On Sun, Oct 12, 2008 at 05:19:51PM -0500, Eric Sandeen wrote:
>> Christoph Hellwig wrote:
>>> When we skip unrecognized options in xfs_fs_remount we should just break
>>> out of the switch and not return because otherwise we may skip clearing
>>> the xfs-internal read-only flag.  This will only show up on some
>>> operations like touch because most read-only checks are done by the VFS
>>> which things this filesystem is r/w.  Eventually we should replace the
>>> XFS read-only flag with a helper that always checks the VFS flag to make
>>> sure they can never get out of sync.
>>>
>>> Bug reported and fix verified by Marcel Beister on #xfs.
>> Seems reasonable.
>>
>> I think this is 2.6.27.1 material?
> 
> Yes.
> 
> 

The recent bug on oss.sgi.com is probably the same; I'm updating it now.

-Eric