Merge tag 'docs-5.7-2' of git://git.lwn.net/linux

[linux-block.git] / fs / nfs / namespace.c

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index f3ece8ed32033ab3e4e4e807b9b128b54c1da95a..6b063227e34e9de4cbb52bfcbac46cc0d69b309a 100644 (file)
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -145,6 +145,7 @@ struct vfsmount *nfs_d_automount(struct path *path)
        struct vfsmount *mnt = ERR_PTR(-ENOMEM);
        struct nfs_server *server = NFS_SERVER(d_inode(path->dentry));
        struct nfs_client *client = server->nfs_client;
+       int timeout = READ_ONCE(nfs_mountpoint_expiry_timeout);
        int ret;
 
        if (IS_ROOT(path->dentry))
@@ -190,12 +191,12 @@ struct vfsmount *nfs_d_automount(struct path *path)
        if (IS_ERR(mnt))
                goto out_fc;
 
-       if (nfs_mountpoint_expiry_timeout < 0)
+       mntget(mnt); /* prevent immediate expiration */
+       if (timeout <= 0)
                goto out_fc;
 
-       mntget(mnt); /* prevent immediate expiration */
        mnt_set_expiry(mnt, &nfs_automount_list);
-       schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
+       schedule_delayed_work(&nfs_automount_task, timeout);
 
 out_fc:
        put_fs_context(fc);
@@ -233,10 +234,11 @@ const struct inode_operations nfs_referral_inode_operations = {
 static void nfs_expire_automounts(struct work_struct *work)
 {
        struct list_head *list = &nfs_automount_list;
+       int timeout = READ_ONCE(nfs_mountpoint_expiry_timeout);
 
        mark_mounts_for_expiry(list);
-       if (!list_empty(list))
-               schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
+       if (!list_empty(list) && timeout > 0)
+               schedule_delayed_work(&nfs_automount_task, timeout);
 }
 
 void nfs_release_automount_timer(void)
@@ -247,10 +249,7 @@ void nfs_release_automount_timer(void)
 
 /**
  * nfs_do_submount - set up mountpoint when crossing a filesystem boundary
- * @dentry: parent directory
- * @fh: filehandle for new root dentry
- * @fattr: attributes for new root inode
- * @authflavor: security flavor to use when performing the mount
+ * @fc: pointer to struct nfs_fs_context
  *
  */
 int nfs_do_submount(struct fs_context *fc)
@@ -312,3 +311,53 @@ int nfs_submount(struct fs_context *fc, struct nfs_server *server)
        return nfs_do_submount(fc);
 }
 EXPORT_SYMBOL_GPL(nfs_submount);
+
+static int param_set_nfs_timeout(const char *val, const struct kernel_param *kp)
+{
+       long num;
+       int ret;
+
+       if (!val)
+               return -EINVAL;
+       ret = kstrtol(val, 0, &num);
+       if (ret)
+               return -EINVAL;
+       if (num > 0) {
+               if (num >= INT_MAX / HZ)
+                       num = INT_MAX;
+               else
+                       num *= HZ;
+               *((int *)kp->arg) = num;
+               if (!list_empty(&nfs_automount_list))
+                       mod_delayed_work(system_wq, &nfs_automount_task, num);
+       } else {
+               *((int *)kp->arg) = -1*HZ;
+               cancel_delayed_work(&nfs_automount_task);
+       }
+       return 0;
+}
+
+static int param_get_nfs_timeout(char *buffer, const struct kernel_param *kp)
+{
+       long num = *((int *)kp->arg);
+
+       if (num > 0) {
+               if (num >= INT_MAX - (HZ - 1))
+                       num = INT_MAX / HZ;
+               else
+                       num = (num + (HZ - 1)) / HZ;
+       } else
+               num = -1;
+       return scnprintf(buffer, PAGE_SIZE, "%li\n", num);
+}
+
+static const struct kernel_param_ops param_ops_nfs_timeout = {
+       .set = param_set_nfs_timeout,
+       .get = param_get_nfs_timeout,
+};
+#define param_check_nfs_timeout(name, p) __param_check(name, p, int);
+
+module_param(nfs_mountpoint_expiry_timeout, nfs_timeout, 0644);
+MODULE_PARM_DESC(nfs_mountpoint_expiry_timeout,
+               "Set the NFS automounted mountpoint timeout value (seconds)."
+               "Values <= 0 turn expiration off.");