The patch titled
Subject: reiserfs: add comment to explain endianness issue in xattr_hash
has been removed from the -mm tree. Its filename was
reiserfs-add-comment-to-explain-endianness-issue-in-xattr_hash.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Bharath Vedartham <linux.bhar@xxxxxxxxx>
Subject: reiserfs: add comment to explain endianness issue in xattr_hash
csum_partial() gives different results for little-endian and big-endian
hosts. This causes images created on little-endian hosts and mounted on
big endian hosts to see csum mismatches. This causes an endianness bug.
Sparse gives a warning as csum_partial returns a restricted integer type
__wsum_t and xattr_hash expects __u32. This warning acts as a reminder
for this bug and should not be suppressed.
This comment aims to convey these endianness issues.
[akpm@xxxxxxxxxxxxxxxxxxxx: coding-style fixes]
Link: http://lkml.kernel.org/r/20190423161831.GA15387@bharath12345-Inspiron-5559
Signed-off-by: Bharath Vedartham <linux.bhar@xxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Jeff Mahoney <jeffm@xxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/reiserfs/xattr.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/fs/reiserfs/xattr.c~reiserfs-add-comment-to-explain-endianness-issue-in-xattr_hash
+++ a/fs/reiserfs/xattr.c
@@ -450,6 +450,15 @@ fail:
static inline __u32 xattr_hash(const char *msg, int len)
{
+ /*
+ * csum_partial() gives different results for little-endian and
+ * big endian hosts. Images created on little-endian hosts and
+ * mounted on big-endian hosts(and vice versa) will see csum mismatches
+ * when trying to fetch xattrs. Treating the hash as __wsum_t would
+ * lower the frequency of mismatch. This is an endianness bug in
+ * reiserfs. The return statement would result in a sparse warning. Do
+ * not fix the sparse warning so as to not hide a reminder of the bug.
+ */
return csum_partial(msg, len, 0);
}
_
Patches currently in -mm which might be from linux.bhar@xxxxxxxxx are
