[PATCH 5.11 151/329] NFSv4.x: Dont return NFS4ERR_NOMATCHING_LAYOUT if were unmounting

[Greg Kroah-Hartman]

From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

[ Upstream commit 8926cc8302819be9e67f70409ed001ecb2c924a9 ]

If the NFS super block is being unmounted, then we currently may end up
telling the server that we've forgotten the layout while it is actually
still in use by the client.
In that case, just assume that the client will soon return the layout
anyway, and so return NFS4ERR_DELAY in response to the layout recall.

Fixes: 58ac3e59235f ("NFSv4/pnfs: Clean up nfs_layout_find_inode()")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/nfs/callback_proc.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index f7786e00a6a7..ed9d580826f5 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -137,12 +137,12 @@ static struct inode *nfs_layout_find_inode_by_stateid(struct nfs_client *clp,
 		list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
 			if (!pnfs_layout_is_valid(lo))
 				continue;
-			if (stateid != NULL &&
-			    !nfs4_stateid_match_other(stateid, &lo->plh_stateid))
+			if (!nfs4_stateid_match_other(stateid, &lo->plh_stateid))
 				continue;
-			if (!nfs_sb_active(server->super))
-				continue;
-			inode = igrab(lo->plh_inode);
+			if (nfs_sb_active(server->super))
+				inode = igrab(lo->plh_inode);
+			else
+				inode = ERR_PTR(-EAGAIN);
 			rcu_read_unlock();
 			if (inode)
 				return inode;
@@ -176,9 +176,10 @@ static struct inode *nfs_layout_find_inode_by_fh(struct nfs_client *clp,
 				continue;
 			if (nfsi->layout != lo)
 				continue;
-			if (!nfs_sb_active(server->super))
-				continue;
-			inode = igrab(lo->plh_inode);
+			if (nfs_sb_active(server->super))
+				inode = igrab(lo->plh_inode);
+			else
+				inode = ERR_PTR(-EAGAIN);
 			rcu_read_unlock();
 			if (inode)
 				return inode;
-- 
2.30.2