1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* -*- mode: c; c-basic-offset:8; -*- 3 * vim: noexpandtab sw=8 ts=8 sts=0: 4 * 5 * configfs_internal.h - Internal stuff for configfs 6 * 7 * Based on sysfs: 8 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel 9 * 10 * configfs Copyright (C) 2005 Oracle. All rights reserved. 11 */ 12 13 #ifdef pr_fmt 14 #undef pr_fmt 15 #endif 16 17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19 #include <linux/slab.h> 20 #include <linux/list.h> 21 #include <linux/spinlock.h> 22 23 struct configfs_dirent { 24 atomic_t s_count; 25 int s_dependent_count; 26 struct list_head s_sibling; 27 struct list_head s_children; 28 struct list_head s_links; 29 void * s_element; 30 int s_type; 31 umode_t s_mode; 32 struct dentry * s_dentry; 33 struct iattr * s_iattr; 34 #ifdef CONFIG_LOCKDEP 35 int s_depth; 36 #endif 37 }; 38 39 #define CONFIGFS_ROOT 0x0001 40 #define CONFIGFS_DIR 0x0002 41 #define CONFIGFS_ITEM_ATTR 0x0004 42 #define CONFIGFS_ITEM_BIN_ATTR 0x0008 43 #define CONFIGFS_ITEM_LINK 0x0020 44 #define CONFIGFS_USET_DIR 0x0040 45 #define CONFIGFS_USET_DEFAULT 0x0080 46 #define CONFIGFS_USET_DROPPING 0x0100 47 #define CONFIGFS_USET_IN_MKDIR 0x0200 48 #define CONFIGFS_USET_CREATING 0x0400 49 #define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR) 50 51 extern struct mutex configfs_symlink_mutex; 52 extern spinlock_t configfs_dirent_lock; 53 54 extern struct kmem_cache *configfs_dir_cachep; 55 56 extern int configfs_is_root(struct config_item *item); 57 58 extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *); 59 extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *)); 60 61 extern int configfs_create_file(struct config_item *, const struct configfs_attribute *); 62 extern int configfs_create_bin_file(struct config_item *, 63 const struct configfs_bin_attribute *); 64 extern int configfs_make_dirent(struct configfs_dirent *, 65 struct dentry *, void *, umode_t, int); 66 extern int configfs_dirent_is_ready(struct configfs_dirent *); 67 68 extern void configfs_hash_and_remove(struct dentry * dir, const char * name); 69 70 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd); 71 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent); 72 extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr); 73 74 extern struct dentry *configfs_pin_fs(void); 75 extern void configfs_release_fs(void); 76 77 extern struct rw_semaphore configfs_rename_sem; 78 extern const struct file_operations configfs_dir_operations; 79 extern const struct file_operations configfs_file_operations; 80 extern const struct file_operations configfs_bin_file_operations; 81 extern const struct inode_operations configfs_dir_inode_operations; 82 extern const struct inode_operations configfs_root_inode_operations; 83 extern const struct inode_operations configfs_symlink_inode_operations; 84 extern const struct dentry_operations configfs_dentry_ops; 85 86 extern int configfs_symlink(struct inode *dir, struct dentry *dentry, 87 const char *symname); 88 extern int configfs_unlink(struct inode *dir, struct dentry *dentry); 89 90 struct configfs_symlink { 91 struct list_head sl_list; 92 struct config_item *sl_target; 93 }; 94 95 extern int configfs_create_link(struct configfs_symlink *sl, 96 struct dentry *parent, 97 struct dentry *dentry); 98 99 static inline struct config_item * to_item(struct dentry * dentry) 100 { 101 struct configfs_dirent * sd = dentry->d_fsdata; 102 return ((struct config_item *) sd->s_element); 103 } 104 105 static inline struct configfs_attribute * to_attr(struct dentry * dentry) 106 { 107 struct configfs_dirent * sd = dentry->d_fsdata; 108 return ((struct configfs_attribute *) sd->s_element); 109 } 110 111 static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry) 112 { 113 struct configfs_attribute *attr = to_attr(dentry); 114 115 return container_of(attr, struct configfs_bin_attribute, cb_attr); 116 } 117 118 static inline struct config_item *configfs_get_config_item(struct dentry *dentry) 119 { 120 struct config_item * item = NULL; 121 122 spin_lock(&dentry->d_lock); 123 if (!d_unhashed(dentry)) { 124 struct configfs_dirent * sd = dentry->d_fsdata; 125 if (sd->s_type & CONFIGFS_ITEM_LINK) { 126 struct configfs_symlink * sl = sd->s_element; 127 item = config_item_get(sl->sl_target); 128 } else 129 item = config_item_get(sd->s_element); 130 } 131 spin_unlock(&dentry->d_lock); 132 133 return item; 134 } 135 136 static inline void release_configfs_dirent(struct configfs_dirent * sd) 137 { 138 if (!(sd->s_type & CONFIGFS_ROOT)) { 139 kfree(sd->s_iattr); 140 kmem_cache_free(configfs_dir_cachep, sd); 141 } 142 } 143 144 static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd) 145 { 146 if (sd) { 147 WARN_ON(!atomic_read(&sd->s_count)); 148 atomic_inc(&sd->s_count); 149 } 150 return sd; 151 } 152 153 static inline void configfs_put(struct configfs_dirent * sd) 154 { 155 WARN_ON(!atomic_read(&sd->s_count)); 156 if (atomic_dec_and_test(&sd->s_count)) 157 release_configfs_dirent(sd); 158 } 159 160