This is a note to let you know that I've just added the patch titled
ceph: force updating the msg pointer in non-split case
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ceph-force-updating-the-msg-pointer-in-non-split-case.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4cafd0400bcb6187c0d4ab4d4b0229a89ac4f8c2 Mon Sep 17 00:00:00 2001
From: Xiubo Li <xiubli@xxxxxxxxxx>
Date: Thu, 18 May 2023 09:47:23 +0800
Subject: ceph: force updating the msg pointer in non-split case
From: Xiubo Li <xiubli@xxxxxxxxxx>
commit 4cafd0400bcb6187c0d4ab4d4b0229a89ac4f8c2 upstream.
When the MClientSnap reqeust's op is not CEPH_SNAP_OP_SPLIT the
request may still contain a list of 'split_realms', and we need
to skip it anyway. Or it will be parsed as a corrupt snaptrace.
Cc: stable@xxxxxxxxxxxxxxx
Link: https://tracker.ceph.com/issues/61200
Reported-by: Frank Schilder <frans@xxxxxx>
Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
Reviewed-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ceph/snap.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -976,6 +976,19 @@ skip_inode:
continue;
adjust_snap_realm_parent(mdsc, child, realm->ino);
}
+ } else {
+ /*
+ * In the non-split case both 'num_split_inos' and
+ * 'num_split_realms' should be 0, making this a no-op.
+ * However the MDS happens to populate 'split_realms' list
+ * in one of the UPDATE op cases by mistake.
+ *
+ * Skip both lists just in case to ensure that 'p' is
+ * positioned at the start of realm info, as expected by
+ * ceph_update_snap_trace().
+ */
+ p += sizeof(u64) * num_split_inos;
+ p += sizeof(u64) * num_split_realms;
}
/*
Patches currently in stable-queue which might be from xiubli@xxxxxxxxxx are
queue-4.19/ceph-force-updating-the-msg-pointer-in-non-split-case.patch
