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_fragment { 24 atomic_t frag_count; 25 struct rw_semaphore frag_sem; 26 bool frag_dead; 27 }; 28 29 void put_fragment(struct configfs_fragment *); 30 struct configfs_fragment *get_fragment(struct configfs_fragment *); 31 32 struct configfs_dirent { 33 atomic_t s_count; 34 int s_dependent_count; 35 struct list_head s_sibling; 36 struct list_head s_children; 37 struct list_head s_links; 38 void * s_element; 39 int s_type; 40 umode_t s_mode; 41 struct dentry * s_dentry; 42 struct iattr * s_iattr; 43 #ifdef CONFIG_LOCKDEP 44 int s_depth; 45 #endif 46 struct configfs_fragment *s_frag; 47 }; 48 49 #define CONFIGFS_ROOT 0x0001 50 #define CONFIGFS_DIR 0x0002 51 #define CONFIGFS_ITEM_ATTR 0x0004 52 #define CONFIGFS_ITEM_BIN_ATTR 0x0008 53 #define CONFIGFS_ITEM_LINK 0x0020 54 #define CONFIGFS_USET_DIR 0x0040 55 #define CONFIGFS_USET_DEFAULT 0x0080 56 #define CONFIGFS_USET_DROPPING 0x0100 57 #define CONFIGFS_USET_IN_MKDIR 0x0200 58 #define CONFIGFS_USET_CREATING 0x0400 59 #define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR) 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 int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *)); 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 void configfs_hash_and_remove(struct dentry * dir, const char * name); 79 80 extern const unsigned char * configfs_get_name(struct configfs_dirent *sd); 81 extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent); 82 extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr); 83 84 extern struct dentry *configfs_pin_fs(void); 85 extern void configfs_release_fs(void); 86 87 extern struct rw_semaphore configfs_rename_sem; 88 extern const struct file_operations configfs_dir_operations; 89 extern const struct file_operations configfs_file_operations; 90 extern const struct file_operations configfs_bin_file_operations; 91 extern const struct inode_operations configfs_dir_inode_operations; 92 extern const struct inode_operations configfs_root_inode_operations; 93 extern const struct inode_operations configfs_symlink_inode_operations; 94 extern const struct dentry_operations configfs_dentry_ops; 95 96 extern int configfs_symlink(struct inode *dir, struct dentry *dentry, 97 const char *symname); 98 extern int configfs_unlink(struct inode *dir, struct dentry *dentry); 99 100 struct configfs_symlink { 101 struct list_head sl_list; 102 struct config_item *sl_target; 103 }; 104 105 extern int configfs_create_link(struct configfs_symlink *sl, 106 struct dentry *parent, 107 struct dentry *dentry); 108 109 static inline struct config_item * to_item(struct dentry * dentry) 110 { 111 struct configfs_dirent * sd = dentry->d_fsdata; 112 return ((struct config_item *) sd->s_element); 113 } 114 115 static inline struct configfs_attribute * to_attr(struct dentry * dentry) 116 { 117 struct configfs_dirent * sd = dentry->d_fsdata; 118 return ((struct configfs_attribute *) sd->s_element); 119 } 120 121 static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry) 122 { 123 struct configfs_attribute *attr = to_attr(dentry); 124 125 return container_of(attr, struct configfs_bin_attribute, cb_attr); 126 } 127 128 static inline struct config_item *configfs_get_config_item(struct dentry *dentry) 129 { 130 struct config_item * item = NULL; 131 132 spin_lock(&dentry->d_lock); 133 if (!d_unhashed(dentry)) { 134 struct configfs_dirent * sd = dentry->d_fsdata; 135 if (sd->s_type & CONFIGFS_ITEM_LINK) { 136 struct configfs_symlink * sl = sd->s_element; 137 item = config_item_get(sl->sl_target); 138 } else 139 item = config_item_get(sd->s_element); 140 } 141 spin_unlock(&dentry->d_lock); 142 143 return item; 144 } 145 146 static inline void release_configfs_dirent(struct configfs_dirent * sd) 147 { 148 if (!(sd->s_type & CONFIGFS_ROOT)) { 149 kfree(sd->s_iattr); 150 put_fragment(sd->s_frag); 151 kmem_cache_free(configfs_dir_cachep, sd); 152 } 153 } 154 155 static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd) 156 { 157 if (sd) { 158 WARN_ON(!atomic_read(&sd->s_count)); 159 atomic_inc(&sd->s_count); 160 } 161 return sd; 162 } 163 164 static inline void configfs_put(struct configfs_dirent * sd) 165 { 166 WARN_ON(!atomic_read(&sd->s_count)); 167 if (atomic_dec_and_test(&sd->s_count)) 168 release_configfs_dirent(sd); 169 } 170 171