On Wed, Aug 24, 2016 at 11:55:51AM +1000, Dave Chinner wrote:
> On Tue, Aug 23, 2016 at 05:54:13PM +0200, Artem Savkov wrote:
> > Commit "xfs: only return -errno or success from attr ->put_listent" changes
> > the
>
> Please quote commits in --oneline format in changelogs - it makes it
> much easier to find the change you are refering to if there is both
> a commit ID and the text string in the commit message. (i.e. text
> string confirms the commit id is the one you meant to quote).
Noted, thanks.
>
> commit 2a6fba6 ("xfs: only return -errno or success from attr
> ->put_listent") is the one you are refering to here, right?
Yes, that is the one.
> > returnvalue of __xfs_xattr_put_listen to 0 in case when there is
> > insufficient
> > space in the buffer assuming that setting context->count to -1 would be
> > enough,
> > but all of the ->put_listent callers only check seen_enough. This results in
> > a failed assertion:
> > XFS: Assertion failed: context->count >= 0, file: fs/xfs/xfs_xattr.c, line:
> > 175
> > in insufficient buffer size case.
>
> You have a test case? Can you turn it into an xfstest? We really
> need regression tests that cover issues like this....
>
llistxattr02 test from LTP reliably hits this, I'll see how this can be
ported to xfstest.
> > Signed-off-by: Artem Savkov <asavkov@xxxxxxxxxx>
> > ---
> > fs/xfs/xfs_xattr.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
> > index ea62245..6290093 100644
> > --- a/fs/xfs/xfs_xattr.c
> > +++ b/fs/xfs/xfs_xattr.c
> > @@ -147,6 +147,7 @@ __xfs_xattr_put_listent(
> > arraytop = context->count + prefix_len + namelen + 1;
> > if (arraytop > context->firstu) {
> > context->count = -1; /* insufficient space */
> > + context->seen_enough = 1;
> > return 0;
> > }
> > offset = (char *)context->alist + context->count;
>
> Looks sane, though I don't know how to test it yet....
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
--
Regards,
Artem
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