53e0ae9269
Some sysfs operations require dentry and inode. sysfs_get_dentry() looks up and gets dentry for the specified sysfs_dirent. It finds the first ancestor with dentry attached and starts looking up dentries from there. Looking up from the nearest ancestor is necessary to support shadowed directories because we can't reliably lookup dentry for one of the shadows. Dentries for each shadow will be pinned in memory such that they can serve as the starting point for dentry lookup. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
129 lines
4 KiB
C
129 lines
4 KiB
C
struct sysfs_elem_dir {
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struct kobject * kobj;
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};
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struct sysfs_elem_symlink {
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struct sysfs_dirent * target_sd;
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};
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struct sysfs_elem_attr {
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struct attribute * attr;
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};
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struct sysfs_elem_bin_attr {
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struct bin_attribute * bin_attr;
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};
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/*
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* As long as s_count reference is held, the sysfs_dirent itself is
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* accessible. Dereferencing s_elem or any other outer entity
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* requires s_active reference.
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*/
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struct sysfs_dirent {
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atomic_t s_count;
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atomic_t s_active;
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struct sysfs_dirent * s_parent;
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struct sysfs_dirent * s_sibling;
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struct sysfs_dirent * s_children;
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const char * s_name;
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union {
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struct sysfs_elem_dir dir;
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struct sysfs_elem_symlink symlink;
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struct sysfs_elem_attr attr;
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struct sysfs_elem_bin_attr bin_attr;
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} s_elem;
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unsigned int s_flags;
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umode_t s_mode;
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ino_t s_ino;
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struct dentry * s_dentry;
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struct iattr * s_iattr;
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atomic_t s_event;
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};
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#define SD_DEACTIVATED_BIAS INT_MIN
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struct sysfs_addrm_cxt {
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struct sysfs_dirent *parent_sd;
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struct inode *parent_inode;
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struct sysfs_dirent *removed;
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int cnt;
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};
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extern struct vfsmount * sysfs_mount;
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extern struct kmem_cache *sysfs_dir_cachep;
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extern struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
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extern void sysfs_link_sibling(struct sysfs_dirent *sd);
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extern void sysfs_unlink_sibling(struct sysfs_dirent *sd);
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extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
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extern void sysfs_put_active(struct sysfs_dirent *sd);
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extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
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extern void sysfs_put_active_two(struct sysfs_dirent *sd);
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extern void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
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struct sysfs_dirent *parent_sd);
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extern void sysfs_add_one(struct sysfs_addrm_cxt *acxt,
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struct sysfs_dirent *sd);
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extern void sysfs_remove_one(struct sysfs_addrm_cxt *acxt,
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struct sysfs_dirent *sd);
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extern int sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
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extern void sysfs_delete_inode(struct inode *inode);
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extern void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode);
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extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd);
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extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode);
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extern void release_sysfs_dirent(struct sysfs_dirent * sd);
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extern struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
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const unsigned char *name);
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extern struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
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const unsigned char *name);
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extern struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode,
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int type);
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extern int sysfs_add_file(struct sysfs_dirent *dir_sd,
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const struct attribute *attr, int type);
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extern int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);
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extern struct sysfs_dirent *sysfs_find(struct sysfs_dirent *dir, const char * name);
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extern int sysfs_create_subdir(struct kobject *kobj, const char *name,
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struct sysfs_dirent **p_sd);
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extern void sysfs_remove_subdir(struct sysfs_dirent *sd);
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extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
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extern spinlock_t sysfs_assoc_lock;
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extern struct mutex sysfs_mutex;
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extern struct super_block * sysfs_sb;
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extern const struct file_operations sysfs_dir_operations;
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extern const struct file_operations sysfs_file_operations;
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extern const struct file_operations bin_fops;
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extern const struct inode_operations sysfs_dir_inode_operations;
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extern const struct inode_operations sysfs_symlink_inode_operations;
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static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
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{
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return sd->s_flags & SYSFS_TYPE_MASK;
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}
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static inline struct sysfs_dirent * sysfs_get(struct sysfs_dirent * sd)
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{
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if (sd) {
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WARN_ON(!atomic_read(&sd->s_count));
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atomic_inc(&sd->s_count);
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}
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return sd;
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}
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static inline void sysfs_put(struct sysfs_dirent * sd)
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{
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if (sd && atomic_dec_and_test(&sd->s_count))
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release_sysfs_dirent(sd);
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}
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static inline int sysfs_is_shadowed_inode(struct inode *inode)
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{
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return S_ISDIR(inode->i_mode) && inode->i_op->follow_link;
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}
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