Re: IS_ERR Threshold Value

[Randy.Dunlap]

On Wed, 28 Jun 2006 17:13:33 -0600 Erik Frederiksen wrote:

> Hi Nathan,
> 
> On Wed, 2006-06-28 at 16:41, Nathan Scott wrote:
> > 
> > Hmm, I'm not sure I understand the XFS side of your report here - on
> > open, for quota to be coming into play we must be creating a new inode
> > and those code paths inside XFS have no use of IS_ERR/ERR_PTR magic...
> > did you mean there's generic problems here (I can see those macros are
> > used in the generic VFS open() code) ... or am I missing your point?
> 
> Yes, that's right.  The error is being returned from xfs_create when
> quota has been exceeded.  It ends up carrying back to the filp_open call
> in do_sys_open, which returns it as a pointer to a filp structure. 
> Because the errno is so large, IS_ERR reports it as being a valid
> pointer incorrectly.
> 
> XFS has acted correctly.  The only reason I bring it up is this is how
> the bug was brought to my attention.  
> 
> If there won't be any strange side effects (I don't have the experience
> to accurately comment on this), I think turning the threshold value up
> to something we can get away with in IS_ERR_VALUE() would be
> appropriate.

We need to get the threshold == 4095 patch into -mm to make sure
that it doesn't break anything and/or fix whatever it breaks.

Are you planning to do that patch?  If not, someone else (or I) can.

---
~Randy
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