51225039f3
This patch makes dentries and inodes for sysfs directories reclaimable. * sysfs_notify() is modified to walk sysfs_dirent tree instead of dentry tree. * sysfs_update_file() and sysfs_chmod_file() use sysfs_get_dentry() to grab the victim dentry. * sysfs_rename_dir() and sysfs_move_dir() grab all dentries using sysfs_get_dentry() on startup. * Dentries for all shadowed directories are pinned in memory to serve as lookup start point. 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 sysfs_dirent sysfs_root;
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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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