File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/fs/lockd/procfs.c b/fs/lockd/procfs.c
new file mode 100644
index 0000000..2a0a984
--- /dev/null
+++ b/fs/lockd/procfs.c
@@ -0,0 +1,92 @@
+/*
+ * Procfs support for lockd
+ *
+ * Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
+ */
+
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+
+#include "netns.h"
+#include "procfs.h"
+
+/*
+ * We only allow strings that start with 'Y', 'y', or '1'.
+ */
+static ssize_t
+nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
+ loff_t *pos)
+{
+ char *data;
+ struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
+ lockd_net_id);
+
+ if (size < 1)
+ return -EINVAL;
+
+ data = simple_transaction_get(file, buf, size);
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ switch(data[0]) {
+ case 'Y':
+ case 'y':
+ case '1':
+ locks_end_grace(&ln->lockd_manager);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return size;
+}
+
+static ssize_t
+nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
+ loff_t *pos)
+{
+ struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
+ lockd_net_id);
+ char resp[3];
+
+ resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N';
+ resp[1] = '\n';
+ resp[2] = '\0';
+
+ return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp));
+}
+
+static const struct file_operations lockd_end_grace_operations = {
+ .write = nlm_end_grace_write,
+ .read = nlm_end_grace_read,
+ .llseek = default_llseek,
+ .release = simple_transaction_release,
+ .owner = THIS_MODULE,
+};
+
+int __init
+lockd_create_procfs(void)
+{
+ struct proc_dir_entry *entry;
+
+ entry = proc_mkdir("fs/lockd", NULL);
+ if (!entry)
+ return -ENOMEM;
+ entry = proc_create("nlm_end_grace", S_IRUGO|S_IWUSR, entry,
+ &lockd_end_grace_operations);
+ if (!entry) {
+ remove_proc_entry("fs/lockd", NULL);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+void __exit
+lockd_remove_procfs(void)
+{
+ remove_proc_entry("fs/lockd/nlm_end_grace", NULL);
+ remove_proc_entry("fs/lockd", NULL);
+}