saner umount_tree()/release_mounts(), part 1
global list of release_mounts() fodder, protected by namespace_sem;
eventually, all umount_tree() callers will use it as kill list.
Helper picking the contents of that list, releasing namespace_sem
and doing release_mounts() on what it got.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namespace.c b/fs/namespace.c
index d7bb5a55..0d91711 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1119,6 +1119,8 @@
EXPORT_SYMBOL(may_umount);
+static LIST_HEAD(unmounted); /* protected by namespace_sem */
+
void release_mounts(struct list_head *head)
{
struct mount *mnt;
@@ -1143,6 +1145,14 @@
}
}
+static void namespace_unlock(void)
+{
+ LIST_HEAD(head);
+ list_splice_init(&unmounted, &head);
+ up_write(&namespace_sem);
+ release_mounts(&head);
+}
+
/*
* vfsmount lock must be held for write
* namespace_sem must be held for write
@@ -1252,17 +1262,16 @@
event++;
if (!(flags & MNT_DETACH))
- shrink_submounts(mnt, &umount_list);
+ shrink_submounts(mnt, &unmounted);
retval = -EBUSY;
if (flags & MNT_DETACH || !propagate_mount_busy(mnt, 2)) {
if (!list_empty(&mnt->mnt_list))
- umount_tree(mnt, 1, &umount_list);
+ umount_tree(mnt, 1, &unmounted);
retval = 0;
}
br_write_unlock(&vfsmount_lock);
- up_write(&namespace_sem);
- release_mounts(&umount_list);
+ namespace_unlock();
return retval;
}