@@ -63,22 +63,6 @@ __setup("devtmpfs.mount=", mount_param);
static struct vfsmount *mnt;
-static struct dentry *public_dev_mount(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data)
-{
- struct super_block *s = mnt->mnt_sb;
- int err;
-
- atomic_inc(&s->s_active);
- down_write(&s->s_umount);
- err = reconfigure_single(s, flags, data);
- if (err < 0) {
- deactivate_locked_super(s);
- return ERR_PTR(err);
- }
- return dget(s->s_root);
-}
-
static struct file_system_type internal_fs_type = {
.name = "devtmpfs",
#ifdef CONFIG_TMPFS
@@ -89,9 +73,40 @@ static struct file_system_type internal_fs_type = {
.kill_sb = kill_litter_super,
};
+/* Simply take a ref on the existing mount */
+static int devtmpfs_get_tree(struct fs_context *fc)
+{
+ struct super_block *sb = mnt->mnt_sb;
+
+ atomic_inc(&sb->s_active);
+ down_write(&sb->s_umount);
+ fc->root = dget(sb->s_root);
+ return 0;
+}
+
+/* Ops are filled in during init depending on underlying shmem or ramfs type */
+struct fs_context_operations devtmpfs_context_ops = {};
+
+/* Call the underlying initialization and set to our ops */
+static int devtmpfs_init_fs_context(struct fs_context *fc)
+{
+ int ret;
+#ifdef CONFIG_TMPFS
+ ret = shmem_init_fs_context(fc);
+#else
+ ret = ramfs_init_fs_context(fc);
+#endif
+ if (ret < 0)
+ return ret;
+
+ fc->ops = &devtmpfs_context_ops;
+
+ return 0;
+}
+
static struct file_system_type dev_fs_type = {
.name = "devtmpfs",
- .mount = public_dev_mount,
+ .init_fs_context = devtmpfs_init_fs_context,
};
static int devtmpfs_submit_req(struct req *req, const char *tmp)
@@ -442,6 +457,31 @@ static int __ref devtmpfsd(void *p)
return 0;
}
+/*
+ * Get the underlying (shmem/ramfs) context ops to build ours
+ */
+static int devtmpfs_configure_context(void)
+{
+ struct fs_context *fc;
+
+ fc = fs_context_for_reconfigure(mnt->mnt_root, mnt->mnt_sb->s_flags,
+ MS_RMT_MASK);
+ if (IS_ERR(fc))
+ return PTR_ERR(fc);
+
+ /* Set up devtmpfs_context_ops based on underlying type */
+ devtmpfs_context_ops.free = fc->ops->free;
+ devtmpfs_context_ops.dup = fc->ops->dup;
+ devtmpfs_context_ops.parse_param = fc->ops->parse_param;
+ devtmpfs_context_ops.parse_monolithic = fc->ops->parse_monolithic;
+ devtmpfs_context_ops.get_tree = &devtmpfs_get_tree;
+ devtmpfs_context_ops.reconfigure = fc->ops->reconfigure;
+
+ put_fs_context(fc);
+
+ return 0;
+}
+
/*
* Create devtmpfs instance, driver-core devices will add their device
* nodes here.
@@ -456,6 +496,13 @@ int __init devtmpfs_init(void)
pr_err("unable to create devtmpfs %ld\n", PTR_ERR(mnt));
return PTR_ERR(mnt);
}
+
+ err = devtmpfs_configure_context();
+ if (err) {
+ pr_err("unable to configure devtmpfs type %d\n", err);
+ return err;
+ }
+
err = register_filesystem(&dev_fs_type);
if (err) {
pr_err("unable to register devtmpfs type %d\n", err);
To finalize mount API conversion, remove the ->mount op from the public instance in favor of ->get_tree etc. Copy most ops from the underlying ops vector (whether it's shmem or ramfs) and substitute our own ->get_tree which simply takes an extra reference on the existing internal mount as before. Thanks to Al for the fs_context_for_reconfigure() idea. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Eric Sandeen <sandeen@redhat.com> --- drivers/base/devtmpfs.c | 81 ++++++++++++++++++++++++++++++++--------- 1 file changed, 64 insertions(+), 17 deletions(-)