3 files changed, 43 insertions, 1 deletions

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index d6a9db0a8545..1e6bfdbc1aff 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -411,6 +411,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
                         struct page *page, void *fsdata)
 {
         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
+        struct nfs_open_context *ctx = nfs_file_open_context(file);
         int status;
 
         dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n",
@@ -446,6 +447,13 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
         if (status < 0)
                 return status;
         NFS_I(mapping->host)->write_io += copied;
+
+        if (nfs_ctx_key_to_expire(ctx)) {
+                status = nfs_wb_all(mapping->host);
+                if (status < 0)
+                        return status;
+        }
+
         return copied;
 }
 
@@ -642,7 +650,8 @@ static int nfs_need_sync_write(struct file *filp, struct inode *inode)
         if (IS_SYNC(inode) || (filp->f_flags & O_DSYNC))
                 return 1;
         ctx = nfs_file_open_context(filp);
-        if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags))
+        if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags) ||
+            nfs_ctx_key_to_expire(ctx))
                 return 1;
         return 0;
 }
@@ -656,6 +665,10 @@ ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
         ssize_t result;
         size_t count = iov_length(iov, nr_segs);
 
+        result = nfs_key_timeout_notify(iocb->ki_filp, inode);
+        if (result)
+                return result;
+
         if (iocb->ki_filp->f_flags & O_DIRECT)
                 return nfs_file_direct_write(iocb, iov, nr_segs, pos, true);
 
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 50f7068903b9..2415198d29ad 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -431,6 +431,8 @@ void nfs_request_remove_commit_list(struct nfs_page *req,
 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
                     struct inode *inode,
                     struct nfs_direct_req *dreq);
+int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
+bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
 
 #ifdef CONFIG_MIGRATION
 extern int nfs_migrate_page(struct address_space *,
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index d37e8ca9ab86..94eb4504731a 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -876,6 +876,33 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
 }
 
 /*
+ * Avoid buffered writes when a open context credential's key would
+ * expire soon.
+ *
+ * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL.
+ *
+ * Return 0 and set a credential flag which triggers the inode to flush
+ * and performs  NFS_FILE_SYNC writes if the key will expired within
+ * RPC_KEY_EXPIRE_TIMEO.
+ */
+int
+nfs_key_timeout_notify(struct file *filp, struct inode *inode)
+{
+        struct nfs_open_context *ctx = nfs_file_open_context(filp);
+        struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
+
+        return rpcauth_key_timeout_notify(auth, ctx->cred);
+}
+
+/*
+ * Test if the open context credential key is marked to expire soon.
+ */
+bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx)
+{
+        return rpcauth_cred_key_to_expire(ctx->cred);
+}
+
+/*
  * If the page cache is marked as unsafe or invalid, then we can't rely on
  * the PageUptodate() flag. In this case, we will need to turn off
  * write optimisations that depend on the page contents being correct.