From: NeilBrown <neilb@suse.com>
Subject: KABI FIX FOR: NFS: Pass error information to the pgio error cleanup routine
Patch-mainline: Never, kabi
References: git-fixes

Return this function signature to what it was.
It isn't obvious that this is safe, but I think it is.

It is extremely unlikely that an external module would either define an
error_cleanup function (there is one for direct IO and one for async IO,
both internal) and it is also unlikely that an external module would
call one - all current calls are in pagelist.c which is very much
internal code.

But suppose they did:

 If an external module defined a function, that function would be passed
 and extra arg which it could ignore - and this is safe.  The direct IO
 error_cleanup function ignores the error code.

 If an external module called an error_cleanup function, that function
 would read garbage for the error code.  That garbage would almost
 certainly be NOT recognised as a 'fatal' error so the pre-fix behaviour
 would result which is what that caller expected.  If by bad luck the
 did appear fatal ....  I think it would just cause the error to spread
 to a few more requests.  I think this is a mild consequence for an
 extremely unlikely event.

Signed-off-by: NeilBrown <neilb@suse.com>

---
 include/linux/nfs_xdr.h |    4 ++++
 1 file changed, 4 insertions(+)

--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1509,7 +1509,11 @@ struct nfs_commit_data {
 };
 
 struct nfs_pgio_completion_ops {
+#ifdef __GENKSYMS__
+	void	(*error_cleanup)(struct list_head *head);
+#else
 	void	(*error_cleanup)(struct list_head *head, int);
+#endif
 	void	(*init_hdr)(struct nfs_pgio_header *hdr);
 	void	(*completion)(struct nfs_pgio_header *hdr);
 	void	(*reschedule_io)(struct nfs_pgio_header *hdr);