![Linus Torvalds](/assets/img/avatar_default.png)
Pull vfs mount updates from Al Viro: "The first part of mount updates. Convert filesystems to use the new mount API" * 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) mnt_init(): call shmem_init() unconditionally constify ksys_mount() string arguments don't bother with registering rootfs init_rootfs(): don't bother with init_ramfs_fs() vfs: Convert smackfs to use the new mount API vfs: Convert selinuxfs to use the new mount API vfs: Convert securityfs to use the new mount API vfs: Convert apparmorfs to use the new mount API vfs: Convert openpromfs to use the new mount API vfs: Convert xenfs to use the new mount API vfs: Convert gadgetfs to use the new mount API vfs: Convert oprofilefs to use the new mount API vfs: Convert ibmasmfs to use the new mount API vfs: Convert qib_fs/ipathfs to use the new mount API vfs: Convert efivarfs to use the new mount API vfs: Convert configfs to use the new mount API vfs: Convert binfmt_misc to use the new mount API convenience helper: get_tree_single() convenience helper get_tree_nodev() vfs: Kill sget_userns() ...
172 lines
4.1 KiB
C
172 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* mount.c - operations for initializing and mounting configfs.
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*
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* Based on sysfs:
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* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
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*
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* configfs Copyright (C) 2005 Oracle. All rights reserved.
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*/
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#include <linux/fs.h>
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#include <linux/module.h>
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#include <linux/mount.h>
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#include <linux/fs_context.h>
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#include <linux/pagemap.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/configfs.h>
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#include "configfs_internal.h"
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/* Random magic number */
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#define CONFIGFS_MAGIC 0x62656570
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static struct vfsmount *configfs_mount = NULL;
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struct kmem_cache *configfs_dir_cachep;
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static int configfs_mnt_count = 0;
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static const struct super_operations configfs_ops = {
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.statfs = simple_statfs,
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.drop_inode = generic_delete_inode,
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};
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static struct config_group configfs_root_group = {
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.cg_item = {
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.ci_namebuf = "root",
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.ci_name = configfs_root_group.cg_item.ci_namebuf,
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},
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};
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int configfs_is_root(struct config_item *item)
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{
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return item == &configfs_root_group.cg_item;
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}
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static struct configfs_dirent configfs_root = {
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.s_sibling = LIST_HEAD_INIT(configfs_root.s_sibling),
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.s_children = LIST_HEAD_INIT(configfs_root.s_children),
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.s_element = &configfs_root_group.cg_item,
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.s_type = CONFIGFS_ROOT,
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.s_iattr = NULL,
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};
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static int configfs_fill_super(struct super_block *sb, struct fs_context *fc)
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{
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struct inode *inode;
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struct dentry *root;
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sb->s_blocksize = PAGE_SIZE;
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sb->s_blocksize_bits = PAGE_SHIFT;
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sb->s_magic = CONFIGFS_MAGIC;
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sb->s_op = &configfs_ops;
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sb->s_time_gran = 1;
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inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
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&configfs_root, sb);
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if (inode) {
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inode->i_op = &configfs_root_inode_operations;
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inode->i_fop = &configfs_dir_operations;
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/* directory inodes start off with i_nlink == 2 (for "." entry) */
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inc_nlink(inode);
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} else {
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pr_debug("could not get root inode\n");
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return -ENOMEM;
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}
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root = d_make_root(inode);
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if (!root) {
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pr_debug("%s: could not get root dentry!\n",__func__);
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return -ENOMEM;
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}
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config_group_init(&configfs_root_group);
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configfs_root_group.cg_item.ci_dentry = root;
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root->d_fsdata = &configfs_root;
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sb->s_root = root;
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sb->s_d_op = &configfs_dentry_ops; /* the rest get that */
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return 0;
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}
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static int configfs_get_tree(struct fs_context *fc)
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{
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return get_tree_single(fc, configfs_fill_super);
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}
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static const struct fs_context_operations configfs_context_ops = {
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.get_tree = configfs_get_tree,
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};
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static int configfs_init_fs_context(struct fs_context *fc)
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{
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fc->ops = &configfs_context_ops;
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return 0;
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}
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static struct file_system_type configfs_fs_type = {
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.owner = THIS_MODULE,
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.name = "configfs",
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.init_fs_context = configfs_init_fs_context,
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.kill_sb = kill_litter_super,
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};
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MODULE_ALIAS_FS("configfs");
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struct dentry *configfs_pin_fs(void)
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{
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int err = simple_pin_fs(&configfs_fs_type, &configfs_mount,
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&configfs_mnt_count);
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return err ? ERR_PTR(err) : configfs_mount->mnt_root;
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}
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void configfs_release_fs(void)
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{
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simple_release_fs(&configfs_mount, &configfs_mnt_count);
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}
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static int __init configfs_init(void)
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{
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int err = -ENOMEM;
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configfs_dir_cachep = kmem_cache_create("configfs_dir_cache",
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sizeof(struct configfs_dirent),
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0, 0, NULL);
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if (!configfs_dir_cachep)
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goto out;
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err = sysfs_create_mount_point(kernel_kobj, "config");
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if (err)
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goto out2;
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err = register_filesystem(&configfs_fs_type);
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if (err)
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goto out3;
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return 0;
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out3:
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pr_err("Unable to register filesystem!\n");
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sysfs_remove_mount_point(kernel_kobj, "config");
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out2:
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kmem_cache_destroy(configfs_dir_cachep);
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configfs_dir_cachep = NULL;
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out:
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return err;
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}
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static void __exit configfs_exit(void)
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{
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unregister_filesystem(&configfs_fs_type);
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sysfs_remove_mount_point(kernel_kobj, "config");
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kmem_cache_destroy(configfs_dir_cachep);
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configfs_dir_cachep = NULL;
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}
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MODULE_AUTHOR("Oracle");
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MODULE_LICENSE("GPL");
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MODULE_VERSION("0.0.2");
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MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration.");
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core_initcall(configfs_init);
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module_exit(configfs_exit);
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