Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc mount API conversions from Al Viro:
 "Conversions to new API for shmem and friends and for mount_mtd()-using
  filesystems.

  As for the rest of the mount API conversions in -next, some of them
  belong in the individual trees (e.g. binderfs one should definitely go
  through android folks, after getting redone on top of their changes).
  I'm going to drop those and send the rest (trivial ones + stuff ACKed
  by maintainers) in a separate series - by that point they are
  independent from each other.

  Some stuff has already migrated into individual trees (NFS conversion,
  for example, or FUSE stuff, etc.); those presumably will go through
  the regular merges from corresponding trees."

* 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Make fs_parse() handle fs_param_is_fd-type params better
  vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
  shmem_parse_one(): switch to use of fs_parse()
  shmem_parse_options(): take handling a single option into a helper
  shmem_parse_options(): don't bother with mpol in separate variable
  shmem_parse_options(): use a separate structure to keep the results
  make shmem_fill_super() static
  make ramfs_fill_super() static
  devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()
  vfs: Convert squashfs to use the new mount API
  mtd: Kill mount_mtd()
  vfs: Convert jffs2 to use the new mount API
  vfs: Convert cramfs to use the new mount API
  vfs: Convert romfs to use the new mount API
  vfs: Add a single-or-reconfig keying to vfs_get_super()

1 files changed, 28 insertions, 7 deletions

diff --git a/fs/super.c b/fs/super.c
index 2d679db9e8c7..8020974b2a68 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1164,9 +1164,11 @@ int vfs_get_super(struct fs_context *fc,
 {
         int (*test)(struct super_block *, struct fs_context *);
         struct super_block *sb;
+        int err;
 
         switch (keying) {
         case vfs_get_single_super:
+        case vfs_get_single_reconf_super:
                 test = test_single_super;
                 break;
         case vfs_get_keyed_super:
@@ -1184,18 +1186,29 @@ int vfs_get_super(struct fs_context *fc,
                 return PTR_ERR(sb);
 
         if (!sb->s_root) {
-                int err = fill_super(sb, fc);
-                if (err) {
-                        deactivate_locked_super(sb);
-                        return err;
-                }
+                err = fill_super(sb, fc);
+                if (err)
+                        goto error;
 
                 sb->s_flags |= SB_ACTIVE;
+                fc->root = dget(sb->s_root);
+        } else {
+                fc->root = dget(sb->s_root);
+                if (keying == vfs_get_single_reconf_super) {
+                        err = reconfigure_super(fc);
+                        if (err < 0) {
+                                dput(fc->root);
+                                fc->root = NULL;
+                                goto error;
+                        }
+                }
         }
 
-        BUG_ON(fc->root);
-        fc->root = dget(sb->s_root);
         return 0;
+
+error:
+        deactivate_locked_super(sb);
+        return err;
 }
 EXPORT_SYMBOL(vfs_get_super);
 
@@ -1215,6 +1228,14 @@ int get_tree_single(struct fs_context *fc,
 }
 EXPORT_SYMBOL(get_tree_single);
 
+int get_tree_single_reconf(struct fs_context *fc,
+                  int (*fill_super)(struct super_block *sb,
+                                    struct fs_context *fc))
+{
+        return vfs_get_super(fc, vfs_get_single_reconf_super, fill_super);
+}
+EXPORT_SYMBOL(get_tree_single_reconf);
+
 int get_tree_keyed(struct fs_context *fc,
                   int (*fill_super)(struct super_block *sb,
                                     struct fs_context *fc),