1 struct sysfs_elem_dir {
5 struct sysfs_elem_symlink {
6 struct sysfs_dirent * target_sd;
9 struct sysfs_elem_attr {
10 struct attribute * attr;
13 struct sysfs_elem_bin_attr {
14 struct bin_attribute * bin_attr;
18 * As long as s_count reference is held, the sysfs_dirent itself is
19 * accessible. Dereferencing s_elem or any other outer entity
20 * requires s_active reference.
24 struct rw_semaphore s_active;
25 struct sysfs_dirent * s_parent;
26 struct list_head s_sibling;
27 struct list_head s_children;
31 struct sysfs_elem_dir dir;
32 struct sysfs_elem_symlink symlink;
33 struct sysfs_elem_attr attr;
34 struct sysfs_elem_bin_attr bin_attr;
40 struct dentry * s_dentry;
41 struct iattr * s_iattr;
46 * A sysfs file which deletes another file when written to need to
47 * write lock the s_active of the victim while its s_active is read
48 * locked for the write operation. Tell lockdep that this is okay.
50 enum sysfs_s_active_class
52 SYSFS_S_ACTIVE_NORMAL, /* file r/w access, etc - default */
53 SYSFS_S_ACTIVE_DEACTIVATE, /* file deactivation */
56 extern struct vfsmount * sysfs_mount;
57 extern struct kmem_cache *sysfs_dir_cachep;
59 extern void sysfs_delete_inode(struct inode *inode);
60 extern struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent *);
61 extern int sysfs_create(struct sysfs_dirent *sd, struct dentry *dentry,
62 int mode, int (*init)(struct inode *));
64 extern void release_sysfs_dirent(struct sysfs_dirent * sd);
65 extern int sysfs_dirent_exist(struct sysfs_dirent *, const unsigned char *);
66 extern struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode,
68 extern void sysfs_attach_dirent(struct sysfs_dirent *sd,
69 struct sysfs_dirent *parent_sd,
70 struct dentry *dentry);
72 extern int sysfs_add_file(struct dentry *, const struct attribute *, int);
73 extern int sysfs_hash_and_remove(struct dentry * dir, const char * name);
74 extern struct sysfs_dirent *sysfs_find(struct sysfs_dirent *dir, const char * name);
76 extern int sysfs_create_subdir(struct kobject *, const char *, struct dentry **);
77 extern void sysfs_remove_subdir(struct dentry *);
79 extern void sysfs_drop_dentry(struct sysfs_dirent *sd);
80 extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
82 extern spinlock_t sysfs_lock;
83 extern spinlock_t kobj_sysfs_assoc_lock;
84 extern struct rw_semaphore sysfs_rename_sem;
85 extern struct super_block * sysfs_sb;
86 extern const struct file_operations sysfs_dir_operations;
87 extern const struct file_operations sysfs_file_operations;
88 extern const struct file_operations bin_fops;
89 extern const struct inode_operations sysfs_dir_inode_operations;
90 extern const struct inode_operations sysfs_symlink_inode_operations;
92 static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd)
95 WARN_ON(!atomic_read(&sd->s_count));
96 atomic_inc(&sd->s_count);
101 static inline void sysfs_put(struct sysfs_dirent * sd)
103 if (sd && atomic_dec_and_test(&sd->s_count))
104 release_sysfs_dirent(sd);
108 * sysfs_get_active - get an active reference to sysfs_dirent
109 * @sd: sysfs_dirent to get an active reference to
111 * Get an active reference of @sd. This function is noop if @sd
115 * Pointer to @sd on success, NULL on failure.
117 static inline struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
120 if (unlikely(!down_read_trylock(&sd->s_active)))
127 * sysfs_put_active - put an active reference to sysfs_dirent
128 * @sd: sysfs_dirent to put an active reference to
130 * Put an active reference to @sd. This function is noop if @sd
133 static inline void sysfs_put_active(struct sysfs_dirent *sd)
136 up_read(&sd->s_active);
140 * sysfs_get_active_two - get active references to sysfs_dirent and parent
141 * @sd: sysfs_dirent of interest
143 * Get active reference to @sd and its parent. Parent's active
144 * reference is grabbed first. This function is noop if @sd is
148 * Pointer to @sd on success, NULL on failure.
150 static inline struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd)
153 if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent)))
155 if (unlikely(!sysfs_get_active(sd))) {
156 sysfs_put_active(sd->s_parent);
164 * sysfs_put_active_two - put active references to sysfs_dirent and parent
165 * @sd: sysfs_dirent of interest
167 * Put active references to @sd and its parent. This function is
168 * noop if @sd is NULL.
170 static inline void sysfs_put_active_two(struct sysfs_dirent *sd)
173 sysfs_put_active(sd);
174 sysfs_put_active(sd->s_parent);
179 * sysfs_deactivate - deactivate sysfs_dirent
180 * @sd: sysfs_dirent to deactivate
182 * Deny new active references and drain existing ones. s_active
183 * will be unlocked when the sysfs_dirent is released.
185 static inline void sysfs_deactivate(struct sysfs_dirent *sd)
187 down_write_nested(&sd->s_active, SYSFS_S_ACTIVE_DEACTIVATE);
189 /* s_active will be unlocked by the thread doing the final put
190 * on @sd. Lie to lockdep.
192 rwsem_release(&sd->s_active.dep_map, 1, _RET_IP_);
195 static inline int sysfs_is_shadowed_inode(struct inode *inode)
197 return S_ISDIR(inode->i_mode) && inode->i_op->follow_link;