Re: [RFC][PATCH] Multiple mount protection

[Kalpak Shah <kalpak@clusterfs.com>]

On Thu, 2007-05-31 at 12:16 -0400, Theodore Tso wrote:
> On Thu, May 31, 2007 at 02:28:33AM +0530, Kalpak Shah wrote:
> > 
> > So can I assume that the INCOMPAT_MMP flag and the s_mmp_interval and
> > s_mmp_block superblock fields will be reserved regardless of whether the
> > patches go into ext4? I had attached the patches in the last mail so you
> > can share your views on them.
> 
> Yes, i've reserved the code point and superblock fields.

Thanks.

>   I'm not going to add INCOMPAT_MMP flag to the supported file until I get and
> integrate the patch ext2fs_open() that actually tests for the flag,
> though, since that would be a bit silly.
> 
> I assume the patch will add a flag to ext2fs_open which skips the MMP
> checking.

Yes I have added a EXT2_FLAG_SKIP_MMP flag to ext2fs_open() to bypass
MMP which will be set if tunefs is used with -f option. Also MMP check
will not be run if the filesystem is being opened readonly.

Thanks,
Kalpak.

>   After all, tune2fs is allowed to make changes to the
> superblock while the filesystem is mounted.  So it needs to be able to
> open the filesystem read/only even if it is mounted.
> 
> Regards,
> 
> 						- Ted