On Wed, 2014-12-10 at 17:32 +0100, Rasmus Villemoes wrote: > Relying on the sign (after casting to int) of the difference of two > quantities for comparison is usually wrong. For example, should a-b > turn out to be 2^31, the return value of cmp(a,b) is -2^31; but that > would also be the return value from cmp(b, a). So a compares less than > b and b compares less than a. One can also easily find three values > a,b,c such that a compares less than b, b compares less than c, but a > does not compare less than c. >
Looks good for me. Thank you for the fix. Reviewed-by: Vyacheslav Dubeyko <sl...@dubeyko.com> Thanks, Vyacheslav Dubeyko. > Signed-off-by: Rasmus Villemoes <li...@rasmusvillemoes.dk> > --- > fs/hfs/catalog.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/fs/hfs/catalog.c b/fs/hfs/catalog.c > index ff0316b925a5..db458ee3a546 100644 > --- a/fs/hfs/catalog.c > +++ b/fs/hfs/catalog.c > @@ -162,14 +162,16 @@ err2: > */ > int hfs_cat_keycmp(const btree_key *key1, const btree_key *key2) > { > - int retval; > + __be32 k1p, k2p; > > - retval = be32_to_cpu(key1->cat.ParID) - be32_to_cpu(key2->cat.ParID); > - if (!retval) > - retval = hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len, > - key2->cat.CName.name, key2->cat.CName.len); > + k1p = key1->cat.ParID; > + k2p = key2->cat.ParID; > > - return retval; > + if (k1p != k2p) > + return be32_to_cpu(k1p) < be32_to_cpu(k2p) ? -1 : 1; > + > + return hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len, > + key2->cat.CName.name, key2->cat.CName.len); > } > > /* Try to get a catalog entry for given catalog id */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/