[PATCH 9/9] nfs: track whether server sets MAY_NOTIFY_LOCK flag

[Jeff Layton <jlayton@redhat.com>]

If it does, then always have the client sleep for the max time before
repolling for the lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/nfs/nfs4_fs.h  | 1 +
 fs/nfs/nfs4proc.c | 7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 9bf64eacba5b..91e4f135a5f2 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -156,6 +156,7 @@ enum {
 	NFS_STATE_RECLAIM_NOGRACE,	/* OPEN stateid needs to recover state */
 	NFS_STATE_POSIX_LOCKS,		/* Posix locks are supported */
 	NFS_STATE_RECOVERY_FAILED,	/* OPEN stateid state recovery failed */
+	NFS_STATE_MAY_NOTIFY_LOCK,	/* server may CB_NOTIFY_LOCK */
 };
 
 struct nfs4_state {
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 6829b998776d..ecd00431fe0c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2537,6 +2537,8 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata,
 		goto out;
 	if (server->caps & NFS_CAP_POSIX_LOCK)
 		set_bit(NFS_STATE_POSIX_LOCKS, &state->flags);
+	if (opendata->o_res.rflags & NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK)
+		set_bit(NFS_STATE_MAY_NOTIFY_LOCK, &state->flags);
 
 	dentry = opendata->dentry;
 	if (d_really_is_negative(dentry)) {
@@ -6230,7 +6232,7 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
 {
 	struct nfs_open_context *ctx;
 	struct nfs4_state *state;
-	unsigned long timeout = NFS4_LOCK_MINTIMEOUT;
+	unsigned long timeout;
 	int status;
 
 	/* verify open state */
@@ -6279,6 +6281,9 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
 	if (status != 0)
 		return status;
 
+	timeout = test_bit(NFS_STATE_MAY_NOTIFY_LOCK, &state->flags) ?
+				NFS4_LOCK_MAXTIMEOUT : NFS4_LOCK_MINTIMEOUT;
+
 	do {
 		struct nfs4_lock_state *lsp = request->fl_u.nfs4_fl.owner;
 		struct inode *inode = lsp->ls_state->inode;
-- 
2.7.4