[PATCH] do shrink_submounts() for all fs types

... and take it out of ->umount_begin() instances.  Call with all locks
already taken (by do_umount()) and leave calling release_mounts() to
caller (it will do release_mounts() anyway, so we can just put into
the same list).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 10 insertions, 13 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 1c78917ec930..7bd74b25930c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -581,6 +581,8 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill)
         }
 }
 
+static void shrink_submounts(struct vfsmount *mnt, struct list_head *umounts);
+
 static int do_umount(struct vfsmount *mnt, int flags)
 {
         struct super_block *sb = mnt->mnt_sb;
@@ -653,6 +655,9 @@ static int do_umount(struct vfsmount *mnt, int flags)
         spin_lock(&vfsmount_lock);
         event++;
 
+        if (!(flags & MNT_DETACH))
+                shrink_submounts(mnt, &umount_list);
+
         retval = -EBUSY;
         if (flags & MNT_DETACH || !propagate_mount_busy(mnt, 2)) {
                 if (!list_empty(&mnt->mnt_list))
@@ -1302,30 +1307,22 @@ resume:
  * process a list of expirable mountpoints with the intent of discarding any
  * submounts of a specific parent mountpoint
  */
-void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts)
+static void shrink_submounts(struct vfsmount *mnt, struct list_head *umounts)
 {
         LIST_HEAD(graveyard);
-        LIST_HEAD(umounts);
-        struct vfsmount *mnt;
+        struct vfsmount *m;
 
-        down_write(&namespace_sem);
-        spin_lock(&vfsmount_lock);
         /* extract submounts of 'mountpoint' from the expiration list */
-        while (select_submounts(mountpoint, &graveyard)) {
+        while (select_submounts(mnt, &graveyard)) {
                 while (!list_empty(&graveyard)) {
-                        mnt = list_first_entry(&graveyard, struct vfsmount,
+                        m = list_first_entry(&graveyard, struct vfsmount,
                                                 mnt_expire);
                         touch_mnt_namespace(mnt->mnt_ns);
-                        umount_tree(mnt, 1, &umounts);
+                        umount_tree(mnt, 1, umounts);
                 }
         }
-        spin_unlock(&vfsmount_lock);
-        up_write(&namespace_sem);
-        release_mounts(&umounts);
 }
 
-EXPORT_SYMBOL_GPL(shrink_submounts);
-
 /*
  * Some copy_from_user() implementations do not return the exact number of
  * bytes remaining to copy on a fault.  But copy_mount_options() requires that.