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>

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 1bdc42f4fd93a92db8e2cd486103afc272f729b5..481fdec09f4edf3a7ca7e7882edd9ac1479d48f3 100644 (file)
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -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;

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 40961366e929ac4d1a18a3f13a2e5dc7494b90d6..e222b25827461385fb780091956a61cb95c0330e 100644 (file)
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -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);

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index bb7723c4f5a5f4997bf5eb35f9abc8635273863b..7db6884f420662b64896e7d737259011aa649aa8 100644 (file)
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -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