introduce fs_context methods

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

1 files changed, 28 insertions, 8 deletions

diff --git a/fs/super.c b/fs/super.c
index 50553233dd15..76b3181c782d 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -894,13 +894,15 @@ int reconfigure_super(struct fs_context *fc)
                 }
         }
 
-        retval = legacy_reconfigure(fc);
-        if (retval) {
-                if (!force)
-                        goto cancel_readonly;
-                /* If forced remount, go ahead despite any errors */
-                WARN(1, "forced remount of a %s fs returned %i\n",
-                     sb->s_type->name, retval);
+        if (fc->ops->reconfigure) {
+                retval = fc->ops->reconfigure(fc);
+                if (retval) {
+                        if (!force)
+                                goto cancel_readonly;
+                        /* If forced remount, go ahead despite any errors */
+                        WARN(1, "forced remount of a %s fs returned %i\n",
+                             sb->s_type->name, retval);
+                }
         }
 
         WRITE_ONCE(sb->s_flags, ((sb->s_flags & ~fc->sb_flags_mask) |
@@ -1294,10 +1296,28 @@ int vfs_get_tree(struct fs_context *fc)
         struct super_block *sb;
         int error;
 
-        error = legacy_get_tree(fc);
+        if (fc->fs_type->fs_flags & FS_REQUIRES_DEV && !fc->source)
+                return -ENOENT;
+
+        if (fc->root)
+                return -EBUSY;
+
+        /* Get the mountable root in fc->root, with a ref on the root and a ref
+         * on the superblock.
+         */
+        error = fc->ops->get_tree(fc);
         if (error < 0)
                 return error;
 
+        if (!fc->root) {
+                pr_err("Filesystem %s get_tree() didn't set fc->root\n",
+                       fc->fs_type->name);
+                /* We don't know what the locking state of the superblock is -
+                 * if there is a superblock.
+                 */
+                BUG();
+        }
+
         sb = fc->root->d_sb;
         WARN_ON(!sb->s_bdi);