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