Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()"

This reverts commit f601f9a2bf7dc1f7ee18feece4c4e2fc6845d6c4.

Tejun writes:
        I'm sorry but can you please revert the whole series?
        get_active() waiting while a node is deactivated has potential
        to lead to deadlock and that deactivate/reactivate interface is
        something fundamentally flawed and that cgroup will have to work
        with the remove_self() like everybody else.  IOW, I think the
        first posting was correct.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index f878e4f2efe7681ad35de92a74c1a1a60c894cac..e565ec096ae997e16369ec7a698d1a43ae1edce3 100644 (file)
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -121,17 +121,13 @@ static int kernfs_link_sibling(struct kernfs_node *kn)
  *     Locking:
  *     mutex_lock(kernfs_mutex)
  */
-static bool kernfs_unlink_sibling(struct kernfs_node *kn)
+static void kernfs_unlink_sibling(struct kernfs_node *kn)
 {
-       if (RB_EMPTY_NODE(&kn->rb))
-               return false;
-
        if (kernfs_type(kn) == KERNFS_DIR)
                kn->parent->dir.subdirs--;
 
        rb_erase(&kn->rb, &kn->parent->dir.children);
        RB_CLEAR_NODE(&kn->rb);
-       return true;
 }
 
 /**
@@ -500,6 +496,7 @@ void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt)
 
                acxt->removed = kn->u.removed_list;
 
+               kernfs_unmap_bin_file(kn);
                kernfs_put(kn);
        }
 }
@@ -857,44 +854,23 @@ static void __kernfs_remove(struct kernfs_addrm_cxt *acxt,
 
        /* unlink the subtree node-by-node */
        do {
-               pos = kernfs_leftmost_descendant(kn);
-
-               /*
-                * We're gonna release kernfs_mutex to unmap bin files,
-                * Make sure @pos doesn't go away inbetween.
-                */
-               kernfs_get(pos);
+               struct kernfs_iattrs *ps_iattr;
 
-               /*
-                * This must be come before unlinking; otherwise, when
-                * there are multiple removers, some may finish before
-                * unmapping is complete.
-                */
-               if (pos->flags & KERNFS_HAS_MMAP) {
-                       mutex_unlock(&kernfs_mutex);
-                       kernfs_unmap_file(pos);
-                       mutex_lock(&kernfs_mutex);
-               }
+               pos = kernfs_leftmost_descendant(kn);
 
-               /*
-                * kernfs_unlink_sibling() succeeds once per node.  Use it
-                * to decide who's responsible for cleanups.
-                */
-               if (!pos->parent || kernfs_unlink_sibling(pos)) {
-                       struct kernfs_iattrs *ps_iattr =
-                               pos->parent ? pos->parent->iattr : NULL;
+               if (pos->parent) {
+                       kernfs_unlink_sibling(pos);
 
                        /* update timestamps on the parent */
+                       ps_iattr = pos->parent->iattr;
                        if (ps_iattr) {
                                ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME;
                                ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME;
                        }
-
-                       pos->u.removed_list = acxt->removed;
-                       acxt->removed = pos;
                }
 
-               kernfs_put(pos);
+               pos->u.removed_list = acxt->removed;
+               acxt->removed = pos;
        } while (pos != kn);
 }
 

diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 404ffd2f27bc0bbbcfa7e45f7d812c7fe99495e9..231a171f48b6f107f729594a82165f4973e56073 100644 (file)
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -700,11 +700,14 @@ static int kernfs_fop_release(struct inode *inode, struct file *filp)
        return 0;
 }
 
-void kernfs_unmap_file(struct kernfs_node *kn)
+void kernfs_unmap_bin_file(struct kernfs_node *kn)
 {
        struct kernfs_open_node *on;
        struct kernfs_open_file *of;
 
+       if (!(kn->flags & KERNFS_HAS_MMAP))
+               return;
+
        spin_lock_irq(&kernfs_open_node_lock);
        on = kn->attr.open;
        if (on)

diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index e9ec38c86074fb79dfe4552e8a17680400ed1f4a..57a93f4d645ca708fad37d0aafecd3bdefbe3889 100644 (file)
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -113,7 +113,7 @@ struct kernfs_node *kernfs_new_node(struct kernfs_root *root, const char *name,
  */
 extern const struct file_operations kernfs_file_fops;
 
-void kernfs_unmap_file(struct kernfs_node *kn);
+void kernfs_unmap_bin_file(struct kernfs_node *kn);
 
 /*
  * symlink.c