Re: [PATCH] fix multilevel diskfilter detection after rev 5024

[Andrey Borzenkov <arvidjaar@gmail.com>]

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В Sun, 16 Jun 2013 03:57:08 +0200
Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com> пишет:

> On 08.06.2013 09:12, Andrey Borzenkov wrote:
> > After commit "Fix order to discover ambigouos RAID before discovering
> > RAIDs on top of it" diskfilter scans all volumes exactly once. This
> > means that only first level is found. Scanning second time will find
> > next level etc.
> > 
> > This means that e.g. MD RAID on top of MD RAID is not found.
> Do you mean raid on top of raid on top of raid? Otherwise I don't
> understand the problem.

Yes. Any configuration with more than two levels.

> > 
> > Change scan to iteratively rescan volume list until nothing new was
> > detected (or scan depth exceeded).
> > 
> > Signed-off-by: Andrey Borzenkov <arvidjaar@gmail.com>
> > 
> > ---
> >  ChangeLog                   |  5 +++++
> >  grub-core/disk/diskfilter.c | 29 +++++++++++++++++++++--------
> >  2 files changed, 26 insertions(+), 8 deletions(-)
> > 
> > diff --git a/ChangeLog b/ChangeLog
> > index 4d8f343..bebcc8a 100644
> > --- a/ChangeLog
> > +++ b/ChangeLog
> > @@ -1,3 +1,8 @@
> > +2013-06-08  Andrey Borzenkov <arvidjaar@gmail.com>
> > +
> > +	* grub-core/disk/diskfilter.c (scan_devices): Iteratively
> > +	rescan diskfilter devices until nothing new is found.
> > +
> >  2013-06-07  Andrey Borzenkov <arvidjaar@gmail.com>
> >  
> >  	* grub-core/script/execute.c (grub_script_execute_sourcecode): Split
> > diff --git a/grub-core/disk/diskfilter.c b/grub-core/disk/diskfilter.c
> > index c8d267a..0455177 100644
> > --- a/grub-core/disk/diskfilter.c
> > +++ b/grub-core/disk/diskfilter.c
> > @@ -188,6 +188,7 @@ scan_disk (const char *name, int accept_diskfilter)
> >    if (!accept_diskfilter && is_valid_diskfilter_name (name))
> >      return 0;
> >  
> > +  /* FIXME do we still need it? It is not called recursively anymore */
> >    if (scan_depth > 100)
> >      return 0;
> Still need it. Consider raid on loopback where underlying OS may call
> into diskfilter again.
> >  
> > @@ -219,6 +220,8 @@ scan_devices (const char *arname)
> >    grub_disk_pull_t pull;
> >    struct grub_diskfilter_vg *vg;
> >    struct grub_diskfilter_lv *lv = NULL;
> > +  int scan_depth;
> > +  int need_rescan;
> >  
> >    for (pull = 0; pull < GRUB_DISK_PULL_MAX; pull++)
> >      for (p = grub_disk_dev_list; p; p = p->next)
> > @@ -231,16 +234,26 @@ scan_devices (const char *arname)
> >  	    return;
> >  	}
> >  
> > -  for (vg = array_list; vg; vg = vg->next)
> > +  scan_depth = 0;
> > +  need_rescan = 1;
> > +  while (need_rescan && scan_depth++ < 100)
> >      {
> > -      if (vg->lvs)
> > -	for (lv = vg->lvs; lv; lv = lv->next)
> > -	  if (!lv->scanned && lv->fullname && lv->became_readable_at)
> > -	    {
> > -	      scan_disk (lv->fullname, 1);
> > -	      lv->scanned = 1;
> > -	    }
> > +      need_rescan = 0;
> > +      for (vg = array_list; vg; vg = vg->next)
> > +	{
> > +	  if (vg->lvs)
> > +	    for (lv = vg->lvs; lv; lv = lv->next)
> > +	      if (!lv->scanned && lv->fullname && lv->became_readable_at)
> > +		{
> > +		  scan_disk (lv->fullname, 1);
> > +		  lv->scanned = 1;
> > +		  need_rescan = 1;
> > +		}
> > +	}
> >      }
> > +
> > +  if (need_rescan)
> > +     grub_error (GRUB_ERR_UNKNOWN_DEVICE, "DISKFILTER scan depth exceeded");
> >  }
> >  
> >  static int
> > 
> 
> 


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