sysfs: reimplement sysfs_drop_dentry()
This patch reimplements sysfs_drop_dentry() such that remove_dir() can
use it to drop dentry instead of using a separate mechanism. With
this change, making directories reclaimable is much easier.
This patch used to contain fixes for two race conditions around
sd->s_dentry but that part has been separated out and included into
mainline early as commit 6aa054aadfea613a437ad0b15d38eca2b963fc0a and
dd14cbc994709a1c5a64ed3621f583c49a27e521.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 01eeb4b..bc11a26 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -372,22 +372,19 @@
static void remove_dir(struct dentry * d)
{
- struct dentry * parent = dget(d->d_parent);
- struct sysfs_dirent * sd;
+ struct dentry *parent = d->d_parent;
+ struct sysfs_dirent *sd = d->d_fsdata;
mutex_lock(&parent->d_inode->i_mutex);
- d_delete(d);
- sd = d->d_fsdata;
+
list_del_init(&sd->s_sibling);
- if (d->d_inode)
- simple_rmdir(parent->d_inode,d);
pr_debug(" o %s removing done (%d)\n",d->d_name.name,
atomic_read(&d->d_count));
mutex_unlock(&parent->d_inode->i_mutex);
- dput(parent);
+ sysfs_drop_dentry(sd);
sysfs_deactivate(sd);
sysfs_put(sd);
}
@@ -404,7 +401,6 @@
struct sysfs_dirent * parent_sd;
struct sysfs_dirent * sd, * tmp;
- dget(dentry);
if (!dentry)
return;
@@ -415,21 +411,17 @@
if (!sd->s_type || !(sd->s_type & SYSFS_NOT_PINNED))
continue;
list_move(&sd->s_sibling, &removed);
- sysfs_drop_dentry(sd, dentry);
}
mutex_unlock(&dentry->d_inode->i_mutex);
list_for_each_entry_safe(sd, tmp, &removed, s_sibling) {
list_del_init(&sd->s_sibling);
+ sysfs_drop_dentry(sd);
sysfs_deactivate(sd);
sysfs_put(sd);
}
remove_dir(dentry);
- /**
- * Drop reference from dget() on entrance.
- */
- dput(dentry);
}
/**