sysfs: Only take active references on attributes.

If we exclude directories and symlinks from the set of sysfs
dirents where we need active references we are left with
sysfs attributes (binary or not).

- Tweak sysfs_deactivate to only do something on attributes
- Move lockdep initialization into sysfs_file_add_mode to
  limit it to just attributes.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Eric W. Biederman 2010-02-11 15:20:00 -08:00 committed by Greg Kroah-Hartman
parent e72ceb8cca
commit a2db684287
3 changed files with 6 additions and 1 deletions

View file

@ -156,6 +156,10 @@ static void sysfs_deactivate(struct sysfs_dirent *sd)
int v;
BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF))
return;
sd->s_sibling = (void *)&wait;
rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_);
@ -315,7 +319,6 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
atomic_set(&sd->s_count, 1);
atomic_set(&sd->s_active, 0);
sysfs_dirent_init_lockdep(sd);
sd->s_name = name;
sd->s_mode = mode;

View file

@ -509,6 +509,7 @@ int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
if (!sd)
return -ENOMEM;
sd->s_attr.attr = (void *)attr;
sysfs_dirent_init_lockdep(sd);
sysfs_addrm_start(&acxt, dir_sd);
rc = sysfs_add_one(&acxt, sd);

View file

@ -79,6 +79,7 @@ struct sysfs_dirent {
#define SYSFS_KOBJ_BIN_ATTR 0x0004
#define SYSFS_KOBJ_LINK 0x0008
#define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK)
#define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
#define SYSFS_FLAG_MASK ~SYSFS_TYPE_MASK
#define SYSFS_FLAG_REMOVED 0x0200