initmpfs: move bdi setup from init_rootfs to init_ramfs
Even though ramfs hasn't got a backing device, commit e0bf68ddec4f ("mm:
bdi init hooks") added one anyway, and put the initialization in
init_rootfs() since that's the first user, leaving it out of init_ramfs()
to avoid duplication.
But initmpfs uses init_tmpfs() instead, so move the init into the
filesystem's init function, add a "once" guard to prevent duplicate
initialization, and call the filesystem init from rootfs init.
This goes part of the way to allowing ramfs to be built as a module.
[akpm@linux-foundation.org; using bit 1 was odd]
Signed-off-by: Rob Landley <rob@landley.net>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 8f7fe32..fb99863 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -249,7 +249,7 @@
{
static unsigned long once;
- if (test_and_set_bit(1, &once))
+ if (test_and_set_bit(0, &once))
return ERR_PTR(-ENODEV);
return mount_nodev(fs_type, flags, data, ramfs_fill_super);
@@ -275,21 +275,34 @@
static int __init init_ramfs_fs(void)
{
- return register_filesystem(&ramfs_fs_type);
-}
-module_init(init_ramfs_fs)
-
-int __init init_rootfs(void)
-{
+ static unsigned long once;
int err;
+ if (test_and_set_bit(0, &once))
+ return 0;
+
err = bdi_init(&ramfs_backing_dev_info);
if (err)
return err;
- err = register_filesystem(&rootfs_fs_type);
+ err = register_filesystem(&ramfs_fs_type);
if (err)
bdi_destroy(&ramfs_backing_dev_info);
return err;
}
+module_init(init_ramfs_fs)
+
+int __init init_rootfs(void)
+{
+ int err = register_filesystem(&rootfs_fs_type);
+
+ if (err)
+ return err;
+
+ err = init_ramfs_fs();
+ if (err)
+ unregister_filesystem(&rootfs_fs_type);
+
+ return err;
+}