[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>

6 files changed, 10 insertions, 26 deletions

diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 5ca3625cd39e..9ba16edc0af2 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -573,7 +573,6 @@ extern const struct file_operations afs_mntpt_file_operations;
 
 extern int afs_mntpt_check_symlink(struct afs_vnode *, struct key *);
 extern void afs_mntpt_kill_timer(void);
-extern void afs_umount_begin(struct vfsmount *, int);
 
 /*
  * proc.c
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index a3510b8ba3e7..2f5503902c37 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -283,11 +283,3 @@ void afs_mntpt_kill_timer(void)
         cancel_delayed_work(&afs_mntpt_expiry_timer);
         flush_scheduled_work();
 }
-
-/*
- * begin unmount by attempting to remove all automounted mountpoints we added
- */
-void afs_umount_begin(struct vfsmount *vfsmnt, int flags)
-{
-        shrink_submounts(vfsmnt, &afs_vfsmounts);
-}
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 36bbce45f44b..4b572b801d8d 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -50,7 +50,6 @@ static const struct super_operations afs_super_ops = {
         .write_inode    = afs_write_inode,
         .destroy_inode  = afs_destroy_inode,
         .clear_inode    = afs_clear_inode,
-        .umount_begin   = afs_umount_begin,
         .put_super      = afs_put_super,
         .show_options   = generic_show_options,
 };
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index a1a95b027136..56c924033b78 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -33,7 +33,6 @@ void dfs_shrink_umount_helper(struct vfsmount *vfsmnt)
 {
         mark_mounts_for_expiry(&cifs_dfs_automount_list);
         mark_mounts_for_expiry(&cifs_dfs_automount_list);
-        shrink_submounts(vfsmnt, &cifs_dfs_automount_list);
 }
 
 /**
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.
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index dd4dfcd632ec..f9219024f31a 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -589,8 +589,6 @@ static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
         struct nfs_server *server = NFS_SB(vfsmnt->mnt_sb);
         struct rpc_clnt *rpc;
 
-        shrink_submounts(vfsmnt, &nfs_automount_list);
-
         if (!(flags & MNT_FORCE))
                 return;
         /* -EIO all pending I/O */