Merge remote-tracking branch 'userns/for-next'

[karo-tx-linux.git] / fs / dcache.c

diff --git a/fs/dcache.c b/fs/dcache.c
index d70df2e0e0da8a6b41d9bfeba798fb4cc9481a80..093a68d5fec5d2129d271066b1f4e4cbc83286f3 100644 (file)
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1372,7 +1372,7 @@ int d_set_mounted(struct dentry *dentry)
        int ret = -ENOENT;
        write_seqlock(&rename_lock);
        for (p = dentry->d_parent; !IS_ROOT(p); p = p->d_parent) {
-               /* Need exclusion wrt. check_submounts_and_drop() */
+               /* Need exclusion wrt. shrink_submounts_and_drop() */
                spin_lock(&p->d_lock);
                if (unlikely(d_unhashed(p))) {
                        spin_unlock(&p->d_lock);
@@ -1477,70 +1477,56 @@ void shrink_dcache_parent(struct dentry *parent)
 }
 EXPORT_SYMBOL(shrink_dcache_parent);
 
-static enum d_walk_ret check_and_collect(void *_data, struct dentry *dentry)
+struct detach_data {
+       struct dentry *found;
+};
+static enum d_walk_ret do_detach_submounts(void *ptr, struct dentry *dentry)
 {
-       struct select_data *data = _data;
-
-       if (d_mountpoint(dentry)) {
-               data->found = -EBUSY;
-               return D_WALK_QUIT;
-       }
-
-       return select_collect(_data, dentry);
-}
+       struct detach_data *data = ptr;
 
-static void check_and_drop(void *_data)
-{
-       struct select_data *data = _data;
+       if (d_mountpoint(dentry))
+               data->found = dentry;
 
-       if (d_mountpoint(data->start))
-               data->found = -EBUSY;
-       if (!data->found)
-               __d_drop(data->start);
+       return data->found ? D_WALK_QUIT : D_WALK_CONTINUE;
 }
 
 /**
- * check_submounts_and_drop - prune dcache, check for submounts and drop
+ * detach_submounts - check for submounts and detach them.
  *
- * All done as a single atomic operation relative to has_unlinked_ancestor().
- * Returns 0 if successfully unhashed @parent.  If there were submounts then
- * return -EBUSY.
+ * @dentry: dentry to find mount points under.
  *
- * @dentry: dentry to prune and drop
+ * If dentry or any of it's children is a mount point detach those mounts.
  */
-int check_submounts_and_drop(struct dentry *dentry)
+void detach_submounts(struct dentry *dentry)
 {
-       int ret = 0;
-
-       /* Negative dentries can be dropped without further checks */
-       if (!dentry->d_inode) {
-               d_drop(dentry);
-               goto out;
-       }
-
+       struct detach_data data;
        for (;;) {
-               struct select_data data;
-
-               INIT_LIST_HEAD(&data.dispose);
-               data.start = dentry;
-               data.found = 0;
+               data.found = NULL;
+               d_walk(dentry, &data, do_detach_submounts, NULL);
 
-               d_walk(dentry, &data, check_and_collect, check_and_drop);
-               ret = data.found;
-
-               if (!list_empty(&data.dispose))
-                       shrink_dentry_list(&data.dispose);
-
-               if (ret <= 0)
+               if (!data.found)
                        break;
 
+               detach_mounts(data.found);
                cond_resched();
        }
+       detach_mounts(dentry);
+}
 
-out:
-       return ret;
+/**
+ * shrink_submounts_and_drop - detach submounts, prune dcache, and drop
+ *
+ * All done as a single atomic operation reletaive to d_set_mounted().
+ *
+ * @dentry: dentry to detach, prune and drop
+ */
+void shrink_submounts_and_drop(struct dentry *dentry)
+{
+       d_drop(dentry);
+       detach_submounts(dentry);
+       shrink_dcache_parent(dentry);
 }
-EXPORT_SYMBOL(check_submounts_and_drop);
+EXPORT_SYMBOL(shrink_submounts_and_drop);
 
 /**
  * __d_alloc   -       allocate a dcache entry