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author | Tejun Heo <htejun@gmail.com> | 2007-06-13 20:45:18 +0200 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-07-12 01:09:07 +0200 |
commit | b6b4a4399c2a83d1af77c99dee0d0b5cc15ec268 (patch) | |
tree | 7a5d3134a338f03ab813024d5501bde1d434c98b /fs/sysfs/dir.c | |
parent | sysfs: fix root sysfs_dirent -> root dentry association (diff) | |
download | linux-b6b4a4399c2a83d1af77c99dee0d0b5cc15ec268.tar.xz linux-b6b4a4399c2a83d1af77c99dee0d0b5cc15ec268.zip |
sysfs: move s_active functions to fs/sysfs/dir.c
These functions are about to receive more complexity and doesn't
really need to be inlined in the first place. Move them from
fs/sysfs/sysfs.h to fs/sysfs/dir.c.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs/sysfs/dir.c')
-rw-r--r-- | fs/sysfs/dir.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 06dff2c30c9b..f5f0b936f181 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; |