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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/configfs/mount.c
Initial import
Diffstat (limited to 'fs/configfs/mount.c')
-rw-r--r--fs/configfs/mount.c175
1 files changed, 175 insertions, 0 deletions
diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c
new file mode 100644
index 000000000..a8f3b589a
--- /dev/null
+++ b/fs/configfs/mount.c
@@ -0,0 +1,175 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * mount.c - operations for initializing and mounting configfs.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+
+#include <linux/configfs.h>
+#include "configfs_internal.h"
+
+/* Random magic number */
+#define CONFIGFS_MAGIC 0x62656570
+
+static struct vfsmount *configfs_mount = NULL;
+struct kmem_cache *configfs_dir_cachep;
+static int configfs_mnt_count = 0;
+
+static const struct super_operations configfs_ops = {
+ .statfs = simple_statfs,
+ .drop_inode = generic_delete_inode,
+};
+
+static struct config_group configfs_root_group = {
+ .cg_item = {
+ .ci_namebuf = "root",
+ .ci_name = configfs_root_group.cg_item.ci_namebuf,
+ },
+};
+
+int configfs_is_root(struct config_item *item)
+{
+ return item == &configfs_root_group.cg_item;
+}
+
+static struct configfs_dirent configfs_root = {
+ .s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling),
+ .s_children = LIST_HEAD_INIT(configfs_root.s_children),
+ .s_element = &configfs_root_group.cg_item,
+ .s_type = CONFIGFS_ROOT,
+ .s_iattr = NULL,
+};
+
+static int configfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct inode *inode;
+ struct dentry *root;
+
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = CONFIGFS_MAGIC;
+ sb->s_op = &configfs_ops;
+ sb->s_time_gran = 1;
+
+ inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
+ &configfs_root, sb);
+ if (inode) {
+ inode->i_op = &configfs_root_inode_operations;
+ inode->i_fop = &configfs_dir_operations;
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
+ } else {
+ pr_debug("could not get root inode\n");
+ return -ENOMEM;
+ }
+
+ root = d_make_root(inode);
+ if (!root) {
+ pr_debug("%s: could not get root dentry!\n",__func__);
+ return -ENOMEM;
+ }
+ config_group_init(&configfs_root_group);
+ configfs_root_group.cg_item.ci_dentry = root;
+ root->d_fsdata = &configfs_root;
+ sb->s_root = root;
+ sb->s_d_op = &configfs_dentry_ops; /* the rest get that */
+ return 0;
+}
+
+static struct dentry *configfs_do_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_single(fs_type, flags, data, configfs_fill_super);
+}
+
+static struct file_system_type configfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "configfs",
+ .mount = configfs_do_mount,
+ .kill_sb = kill_litter_super,
+};
+MODULE_ALIAS_FS("configfs");
+
+struct dentry *configfs_pin_fs(void)
+{
+ int err = simple_pin_fs(&configfs_fs_type, &configfs_mount,
+ &configfs_mnt_count);
+ return err ? ERR_PTR(err) : configfs_mount->mnt_root;
+}
+
+void configfs_release_fs(void)
+{
+ simple_release_fs(&configfs_mount, &configfs_mnt_count);
+}
+
+
+static int __init configfs_init(void)
+{
+ int err = -ENOMEM;
+
+ configfs_dir_cachep = kmem_cache_create("configfs_dir_cache",
+ sizeof(struct configfs_dirent),
+ 0, 0, NULL);
+ if (!configfs_dir_cachep)
+ goto out;
+
+ err = sysfs_create_mount_point(kernel_kobj, "config");
+ if (err)
+ goto out2;
+
+ err = register_filesystem(&configfs_fs_type);
+ if (err)
+ goto out3;
+
+ return 0;
+out3:
+ pr_err("Unable to register filesystem!\n");
+ sysfs_remove_mount_point(kernel_kobj, "config");
+out2:
+ kmem_cache_destroy(configfs_dir_cachep);
+ configfs_dir_cachep = NULL;
+out:
+ return err;
+}
+
+static void __exit configfs_exit(void)
+{
+ unregister_filesystem(&configfs_fs_type);
+ sysfs_remove_mount_point(kernel_kobj, "config");
+ kmem_cache_destroy(configfs_dir_cachep);
+ configfs_dir_cachep = NULL;
+}
+
+MODULE_AUTHOR("Oracle");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.0.2");
+MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
+
+core_initcall(configfs_init);
+module_exit(configfs_exit);