From 2b29ac252afff87b8465b064ca2d9740cf1f6e52 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 14 Jun 2007 03:45:15 +0900 Subject: sysfs: reimplement symlink using sysfs_dirent tree sysfs symlink is implemented by referencing dentry and kobject from sysfs_dirent - symlink entry references kobject, dentry is used to walk the tree. This complicates object lifetimes rules and is dangerous - for example, there is no way to tell to which module the target of a symlink belongs and referencing that kobject can make it linger after the module is gone. This patch reimplements symlink using only sysfs_dirent tree. sd for a symlink points and holds reference to the target sysfs_dirent and all walking is done using sysfs_dirent tree. Simpler and safer. Please read the following message for more info. http://article.gmane.org/gmane.linux.kernel/510293 Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/sysfs.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 718e2e1..6071766 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -3,7 +3,7 @@ struct sysfs_elem_dir { }; struct sysfs_elem_symlink { - struct kobject * target_kobj; + struct sysfs_dirent * target_sd; }; struct sysfs_elem_attr { @@ -100,10 +100,11 @@ static inline struct kobject *sysfs_get_kobject(struct dentry *dentry) spin_lock(&dcache_lock); if (!d_unhashed(dentry)) { struct sysfs_dirent * sd = dentry->d_fsdata; + if (sd->s_type & SYSFS_KOBJ_LINK) - kobj = kobject_get(sd->s_elem.symlink.target_kobj); - else - kobj = kobject_get(sd->s_elem.dir.kobj); + sd = sd->s_elem.symlink.target_sd; + + kobj = kobject_get(sd->s_elem.dir.kobj); } spin_unlock(&dcache_lock); -- cgit v1.1