From: Olga Kornievskaia <kolga@netapp.com>
Date: Wed, 18 Dec 2019 16:50:42 -0500
Subject: [PATCH] NFSv4.x recover from pre-mature loss of openstateid
Git-commit: d826e5b827641ae1bebb33d23a774f4e9bb8e94f
Patch-mainline: v5.6-rc1
References: bsc#1176180

Ever since the commit 0e0cb35b417f, it's possible to lose an open stateid
while retrying a CLOSE due to ERR_OLD_STATEID. Once that happens,
operations that require openstateid fail with EAGAIN which is propagated
to the application then tests like generic/446 and generic/168 fail with
"Resource temporarily unavailable".

Instead of returning this error, initiate state recovery when possible to
recover the open stateid and then try calling nfs4_select_rw_stateid()
again.

Fixes: 0e0cb35b417f ("NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/nfs42proc.c |   36 ++++++++++++++++++++++++++++--------
 fs/nfs/nfs4proc.c  |    2 ++
 fs/nfs/pnfs.c      |    2 --
 3 files changed, 30 insertions(+), 10 deletions(-)

--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -40,8 +40,11 @@ static int _nfs42_proc_fallocate(struct
 
 	status = nfs4_set_rw_stateid(&args.falloc_stateid, lock->open_context,
 			lock, FMODE_WRITE);
-	if (status)
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
 		return status;
+	}
 
 	res.falloc_fattr = nfs_alloc_fattr();
 	if (!res.falloc_fattr)
@@ -239,8 +242,11 @@ static ssize_t _nfs42_proc_copy(struct f
 
 	status = nfs4_set_rw_stateid(&args->src_stateid, src_lock->open_context,
 				     src_lock, FMODE_READ);
-	if (status)
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
 		return status;
+	}
 
 	status = nfs_filemap_write_and_wait_range(file_inode(src)->i_mapping,
 			pos_src, pos_src + (loff_t)count - 1);
@@ -249,8 +255,11 @@ static ssize_t _nfs42_proc_copy(struct f
 
 	status = nfs4_set_rw_stateid(&args->dst_stateid, dst_lock->open_context,
 				     dst_lock, FMODE_WRITE);
-	if (status)
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
 		return status;
+	}
 
 	status = nfs_sync_inode(dst_inode);
 	if (status)
@@ -492,13 +501,19 @@ static loff_t _nfs42_proc_llseek(struct
 
 	status = nfs4_set_rw_stateid(&args.sa_stateid, lock->open_context,
 			lock, FMODE_READ);
-	if (status)
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
 		return status;
+	}
 
 	status = nfs_filemap_write_and_wait_range(inode->i_mapping,
 			offset, LLONG_MAX);
-	if (status)
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
 		return status;
+	}
 
 	status = nfs4_call_sync(server->client, server, &msg,
 				&args.seq_args, &res.seq_res, 0);
@@ -868,13 +883,18 @@ static int _nfs42_proc_clone(struct rpc_
 
 	status = nfs4_set_rw_stateid(&args.src_stateid, src_lock->open_context,
 			src_lock, FMODE_READ);
-	if (status)
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
 		return status;
-
+	}
 	status = nfs4_set_rw_stateid(&args.dst_stateid, dst_lock->open_context,
 			dst_lock, FMODE_WRITE);
-	if (status)
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
 		return status;
+	}
 
 	res.dst_fattr = nfs_alloc_fattr();
 	if (!res.dst_fattr)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3255,6 +3255,8 @@ static int _nfs4_do_setattr(struct inode
 		nfs_put_lock_context(l_ctx);
 		if (status == -EIO)
 			return -EBADF;
+		else if (status == -EAGAIN)
+			goto zero_stateid;
 	} else {
 zero_stateid:
 		nfs4_stateid_copy(&arg->stateid, &zero_stateid);
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1938,8 +1938,6 @@ lookup_again:
 			trace_pnfs_update_layout(ino, pos, count,
 					iomode, lo, lseg,
 					PNFS_UPDATE_LAYOUT_INVALID_OPEN);
-			if (status != -EAGAIN)
-				goto out_unlock;
 			spin_unlock(&ino->i_lock);
 			nfs4_schedule_stateid_recovery(server, ctx->state);
 			pnfs_clear_first_layoutget(lo);