[PATCH 48/75] sysfs: Remove s_dentry

Greg Kroah-Hartman
2007-10-12T22:46:57Z

From: Eric W. Biederman <ebiederm@xmission.com>

The only uses of s_dentry left are the code that maintains
s_dentry and trivial users that don't actually need it.
So this patch removes the s_dentry maintenance code and
restructures the trivial uses to use something else.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
fs/sysfs/dir.c | 32 ++++----------------------------
fs/sysfs/mount.c | 1 -
fs/sysfs/sysfs.h | 1 -
3 files changed, 4 insertions(+), 30 deletions(-)

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 1c3dc5d..36b6c79 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -289,22 +289,7 @@ static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
{
struct sysfs_dirent * sd = dentry->d_fsdata;

- if (sd) {
- /* sd->s_dentry is protected with sysfs_assoc_lock.
- * This allows sysfs_drop_dentry() to dereference it.
- */
- spin_lock(&sysfs_assoc_lock);
-
- /* The dentry might have been deleted or another
- * lookup could have happened updating sd->s_dentry to
- * point the new dentry. Ignore if it isn't pointing
- * to this dentry.
- */
- if (sd->s_dentry == dentry)
- sd->s_dentry = NULL;
- spin_unlock(&sysfs_assoc_lock);
- sysfs_put(sd);
- }
+ sysfs_put(sd);
iput(inode);
}

@@ -352,9 +337,6 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
* @sd: target sysfs_dirent
* @dentry: dentry to associate
*
- * Associate @sd with @dentry. This is protected by
- * sysfs_assoc_lock to avoid race with sysfs_d_iput().
- *
* LOCKING:
* mutex_lock(sysfs_mutex)
*/
@@ -362,12 +344,6 @@ static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
{
dentry->d_op = &sysfs_dentry_ops;
dentry->d_fsdata = sysfs_get(sd);
-
- /* protect sd->s_dentry against sysfs_d_iput */
- spin_lock(&sysfs_assoc_lock);
- sd->s_dentry = dentry;
- spin_unlock(&sysfs_assoc_lock);
-
d_rehash(dentry);
}

@@ -846,7 +822,7 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name)

/* rename */
d_add(new_dentry, NULL);
- d_move(sd->s_dentry, new_dentry);
+ d_move(old_dentry, new_dentry);

error = 0;
goto out_unlock;
@@ -881,7 +857,7 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
error = PTR_ERR(old_dentry);
goto out_dput;
}
- old_parent = sd->s_parent->s_dentry;
+ old_parent = old_dentry->d_parent;

new_parent = sysfs_get_dentry(new_parent_sd);
if (IS_ERR(new_parent)) {
@@ -907,7 +883,7 @@ again:
} else
error = 0;
d_add(new_dentry, NULL);
- d_move(sd->s_dentry, new_dentry);
+ d_move(old_dentry, new_dentry);
dput(new_dentry);

/* Remove from old parent's list and insert into new parent's list. */
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 8989cbb..28bf359 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -56,7 +56,6 @@ static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
iput(inode);
return -ENOMEM;
}
- sysfs_root.s_dentry = root;
root->d_fsdata = &sysfs_root;
sb->s_root = root;
return 0;
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 179e6a2..791b3ed 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -37,7 +37,6 @@ struct sysfs_dirent {
unsigned int s_flags;
umode_t s_mode;
ino_t s_ino;
- struct dentry * s_dentry;
struct iattr * s_iattr;
atomic_t s_event;
};
--
1.5.3.4