diff options
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/dir.c | 88 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 94 |
2 files changed, 94 insertions, 88 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 06dff2c3..f5f0b93 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -20,6 +20,94 @@ spinlock_t kobj_sysfs_assoc_lock = SPIN_LOCK_UNLOCKED; static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED; static DEFINE_IDA(sysfs_ino_ida); +/** + * sysfs_get_active - get an active reference to sysfs_dirent + * @sd: sysfs_dirent to get an active reference to + * + * Get an active reference of @sd. This function is noop if @sd + * is NULL. + * + * RETURNS: + * Pointer to @sd on success, NULL on failure. + */ +struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) +{ + if (sd) { + if (unlikely(!down_read_trylock(&sd->s_active))) + sd = NULL; + } + return sd; +} + +/** + * sysfs_put_active - put an active reference to sysfs_dirent + * @sd: sysfs_dirent to put an active reference to + * + * Put an active reference to @sd. This function is noop if @sd + * is NULL. + */ +void sysfs_put_active(struct sysfs_dirent *sd) +{ + if (sd) + up_read(&sd->s_active); +} + +/** + * sysfs_get_active_two - get active references to sysfs_dirent and parent + * @sd: sysfs_dirent of interest + * + * Get active reference to @sd and its parent. Parent's active + * reference is grabbed first. This function is noop if @sd is + * NULL. + * + * RETURNS: + * Pointer to @sd on success, NULL on failure. + */ +struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd) +{ + if (sd) { + if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent))) + return NULL; + if (unlikely(!sysfs_get_active(sd))) { + sysfs_put_active(sd->s_parent); + return NULL; + } + } + return sd; +} + +/** + * sysfs_put_active_two - put active references to sysfs_dirent and parent + * @sd: sysfs_dirent of interest + * + * Put active references to @sd and its parent. This function is + * noop if @sd is NULL. + */ +void sysfs_put_active_two(struct sysfs_dirent *sd) +{ + if (sd) { + sysfs_put_active(sd); + sysfs_put_active(sd->s_parent); + } +} + +/** + * sysfs_deactivate - deactivate sysfs_dirent + * @sd: sysfs_dirent to deactivate + * + * Deny new active references and drain existing ones. s_active + * will be unlocked when the sysfs_dirent is released. + */ +void sysfs_deactivate(struct sysfs_dirent *sd) +{ + down_write_nested(&sd->s_active, SYSFS_S_ACTIVE_DEACTIVATE); + + /* s_active will be unlocked by the thread doing the final put + * on @sd. Lie to lockdep. + */ + rwsem_release(&sd->s_active.dep_map, 1, _RET_IP_); +} + static int sysfs_alloc_ino(ino_t *pino) { int ino, rc; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 627bf39..f8779ea 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -56,6 +56,12 @@ enum sysfs_s_active_class extern struct vfsmount * sysfs_mount; extern struct kmem_cache *sysfs_dir_cachep; +extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd); +extern void sysfs_put_active(struct sysfs_dirent *sd); +extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd); +extern void sysfs_put_active_two(struct sysfs_dirent *sd); +extern void sysfs_deactivate(struct sysfs_dirent *sd); + extern void sysfs_delete_inode(struct inode *inode); extern void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode); extern struct inode * sysfs_get_inode(struct sysfs_dirent *sd); @@ -104,94 +110,6 @@ static inline void sysfs_put(struct sysfs_dirent * sd) release_sysfs_dirent(sd); } -/** - * sysfs_get_active - get an active reference to sysfs_dirent - * @sd: sysfs_dirent to get an active reference to - * - * Get an active reference of @sd. This function is noop if @sd - * is NULL. - * - * RETURNS: - * Pointer to @sd on success, NULL on failure. - */ -static inline struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) -{ - if (sd) { - if (unlikely(!down_read_trylock(&sd->s_active))) - sd = NULL; - } - return sd; -} - -/** - * sysfs_put_active - put an active reference to sysfs_dirent - * @sd: sysfs_dirent to put an active reference to - * - * Put an active reference to @sd. This function is noop if @sd - * is NULL. - */ -static inline void sysfs_put_active(struct sysfs_dirent *sd) -{ - if (sd) - up_read(&sd->s_active); -} - -/** - * sysfs_get_active_two - get active references to sysfs_dirent and parent - * @sd: sysfs_dirent of interest - * - * Get active reference to @sd and its parent. Parent's active - * reference is grabbed first. This function is noop if @sd is - * NULL. - * - * RETURNS: - * Pointer to @sd on success, NULL on failure. - */ -static inline struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd) -{ - if (sd) { - if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent))) - return NULL; - if (unlikely(!sysfs_get_active(sd))) { - sysfs_put_active(sd->s_parent); - return NULL; - } - } - return sd; -} - -/** - * sysfs_put_active_two - put active references to sysfs_dirent and parent - * @sd: sysfs_dirent of interest - * - * Put active references to @sd and its parent. This function is - * noop if @sd is NULL. - */ -static inline void sysfs_put_active_two(struct sysfs_dirent *sd) -{ - if (sd) { - sysfs_put_active(sd); - sysfs_put_active(sd->s_parent); - } -} - -/** - * sysfs_deactivate - deactivate sysfs_dirent - * @sd: sysfs_dirent to deactivate - * - * Deny new active references and drain existing ones. s_active - * will be unlocked when the sysfs_dirent is released. - */ -static inline void sysfs_deactivate(struct sysfs_dirent *sd) -{ - down_write_nested(&sd->s_active, SYSFS_S_ACTIVE_DEACTIVATE); - - /* s_active will be unlocked by the thread doing the final put - * on @sd. Lie to lockdep. - */ - rwsem_release(&sd->s_active.dep_map, 1, _RET_IP_); -} - static inline int sysfs_is_shadowed_inode(struct inode *inode) { return S_ISDIR(inode->i_mode) && inode->i_op->follow_link; |
