From: Dave Chinner <dchinner@xxxxxxxxxx>
The libxfs dquot buffer code uses do_div() with a 32 bit numerator.
This gives incorrect results as do_div() passes the numerator by
reference as a pointer to a 64 bit value. Hence it does the division
using 32 bits of garbage gives the wrong result.
As per Christoph's suggestion, we can kill the usage of do_div()
here completely and just do the division directly, both in userspace
and kernel space.
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
libxfs/xfs_dquot_buf.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/libxfs/xfs_dquot_buf.c b/libxfs/xfs_dquot_buf.c
index 620d9d3..6bbb0ff 100644
--- a/libxfs/xfs_dquot_buf.c
+++ b/libxfs/xfs_dquot_buf.c
@@ -23,13 +23,8 @@ xfs_calc_dquots_per_chunk(
struct xfs_mount *mp,
unsigned int nbblks) /* basic block units */
{
- unsigned int ndquots;
-
ASSERT(nbblks > 0);
- ndquots = BBTOB(nbblks);
- do_div(ndquots, sizeof(xfs_dqblk_t));
-
- return ndquots;
+ return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
}
/*
--
1.8.4.rc3
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