Matthew Dillon schrieb:
quoted text > :The following patch works perfectly:
> :
> :http://leaf.dragonflybsd.org/~mneumann/hammer-rootmount.diff
> :
> :It isn't possible to use more than one volume, but I think thats a minor
> :problem for a hammer root mount.
> :
> :I'm also not quite sure where this line
> :
> : mp->mnt_flag &= ~MNT_RDONLY; /* mount R/W */
> :..
> :best belongs to. Right now it has the effect that every hammer root mount
> :is read/write. I'm also not 100% sure if I did it right to create the root vnode
> :(which is required in hammer_install_volume, otherwise nlookup seems to fail).
> :...
> : Michael
> :
>
> Normally the root mount is mounted read-only until after the
> filesystem check. But with HAMMER there's a problem doing that
> in that it may cause crash recovery to fail (if the dirty buffers
> created from the crash recovery don't fit in kernel memory). A
> read-write mount is probably needed so I think for now we have to
> keep that code and force it to read-write.
>
> There's a second problem in that I think you are still calling that
> copyin() on the static volume buffer.
>
I conditionalized that until I tried to reduce the patch as much as
possible. I noticed that the copyin just works fine, so
I removed the condition :)
quoted text > It looks like you should be able to get rid of that static buffer
> and just make the volume array point directly to mnt_stat.f_mntfromname,
>
I don't think that works because f_mntfromname contains e.g. "ad4s1d"
and I think to lookup the device we
need a "/dev/ad4s1d". So I have to prepend a /dev/. That's why I used
the static buffer. I don't like that static buffer
either.
quoted text > then conditionalize the copyins. HAMMER doesn't override the field
> until after the volumes have been installed.
>
> Your current patch is also issuing copyin()'s on the constructed kernel
> buffer, which is not legal. I'm not sure why it was still able to
> complete the root mount :-)
>
Yeah, it works perfectly. Strange ;-)
quoted text > In anycase, would you like to make those fixes or should I?
>
I can make them and commit it. Feel free to clean up my mistakes then ;-)
Regards,
Michael
