![Dave Hansen](/assets/img/avatar_default.png)
This is mostly included for parity with dec_nlink(), where we will have some more hooks. This one should stay pretty darn straightforward for now. Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
178 lines
4.6 KiB
C
178 lines
4.6 KiB
C
/* -*- 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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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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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/pagemap.h>
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#include <linux/init.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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struct vfsmount * configfs_mount = NULL;
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struct super_block * configfs_sb = NULL;
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kmem_cache_t *configfs_dir_cachep;
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static int configfs_mnt_count = 0;
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static 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, void *data, int silent)
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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_CACHE_SIZE;
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sb->s_blocksize_bits = PAGE_CACHE_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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configfs_sb = sb;
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inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
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&configfs_root);
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if (inode) {
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inode->i_op = &configfs_dir_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("configfs: could not get root inode\n");
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return -ENOMEM;
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}
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root = d_alloc_root(inode);
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if (!root) {
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pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
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iput(inode);
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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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return 0;
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}
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static int configfs_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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{
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return get_sb_single(fs_type, flags, data, configfs_fill_super, mnt);
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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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.get_sb = configfs_get_sb,
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.kill_sb = kill_litter_super,
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};
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int configfs_pin_fs(void)
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{
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return simple_pin_fs(&configfs_fs_type, &configfs_mount,
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&configfs_mnt_count);
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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 decl_subsys(config, NULL, NULL);
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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, NULL);
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if (!configfs_dir_cachep)
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goto out;
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kset_set_kset_s(&config_subsys, kernel_subsys);
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err = subsystem_register(&config_subsys);
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if (err) {
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kmem_cache_destroy(configfs_dir_cachep);
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configfs_dir_cachep = NULL;
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goto out;
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}
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err = register_filesystem(&configfs_fs_type);
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if (err) {
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printk(KERN_ERR "configfs: Unable to register filesystem!\n");
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subsystem_unregister(&config_subsys);
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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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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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subsystem_unregister(&config_subsys);
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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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module_init(configfs_init);
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module_exit(configfs_exit);
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