[PATCH 2/2] NFSv4/pnfs: pnfs_set_layout_stateid() should update the layout cred

[Trond Myklebust <trondmy@xxxxxxxxx>]

If the cred assigned to the layout that we're updating differs from
the one used to retrieve the new layout segment, then we need to
update the layout plh_lc_cred field.

Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
 fs/nfs/callback_proc.c |  2 +-
 fs/nfs/pnfs.c          | 20 ++++++++++++++++----
 fs/nfs/pnfs.h          |  1 +
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index cd4c6bc81cae..b6ffac9963c8 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -280,7 +280,7 @@ static u32 initiate_file_draining(struct nfs_client *clp,
 		goto unlock;
 	}
 
-	pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
+	pnfs_set_layout_stateid(lo, &args->cbl_stateid, NULL, true);
 	switch (pnfs_mark_matching_lsegs_return(lo, &free_me_list,
 				&args->cbl_range,
 				be32_to_cpu(args->cbl_stateid.seqid))) {
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 542ea8dfd1bc..b21eb4882846 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -903,10 +903,21 @@ pnfs_destroy_all_layouts(struct nfs_client *clp)
 	pnfs_destroy_layouts_byclid(clp, false);
 }
 
+static void
+pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
+{
+	const struct cred *old;
+
+	if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
+		old = xchg(&lo->plh_lc_cred, get_cred(cred));
+		put_cred(old);
+	}
+}
+
 /* update lo->plh_stateid with new if is more recent */
 void
 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
-			bool update_barrier)
+			const struct cred *cred, bool update_barrier)
 {
 	u32 oldseq, newseq, new_barrier = 0;
 
@@ -914,6 +925,7 @@ pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 	newseq = be32_to_cpu(new->seqid);
 
 	if (!pnfs_layout_is_valid(lo)) {
+		pnfs_set_layout_cred(lo, cred);
 		nfs4_stateid_copy(&lo->plh_stateid, new);
 		lo->plh_barrier = newseq;
 		pnfs_clear_layoutreturn_info(lo);
@@ -1109,7 +1121,7 @@ void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
 
 		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
 		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
-		pnfs_set_layout_stateid(lo, stateid, true);
+		pnfs_set_layout_stateid(lo, stateid, NULL, true);
 	} else
 		pnfs_mark_layout_stateid_invalid(lo, &freeme);
 out_unlock:
@@ -2323,14 +2335,14 @@ pnfs_layout_process(struct nfs4_layoutget *lgp)
 
 	if (!pnfs_layout_is_valid(lo)) {
 		/* We have a completely new layout */
-		pnfs_set_layout_stateid(lo, &res->stateid, true);
+		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
 	} else if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
 		/* existing state ID, make sure the sequence number matches. */
 		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
 			dprintk("%s forget reply due to sequence\n", __func__);
 			goto out_forget;
 		}
-		pnfs_set_layout_stateid(lo, &res->stateid, false);
+		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
 	} else {
 		/*
 		 * We got an entirely new state ID.  Mark all segments for the
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 0fafdadc9c8d..cfb89d47c79d 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -267,6 +267,7 @@ bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo);
 void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
 			     const nfs4_stateid *new,
+			     const struct cred *cred,
 			     bool update_barrier);
 int pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 				struct list_head *tmp_list,
-- 
2.24.1