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| author | Tejun Heo <htejun@gmail.com> | 2007-06-13 20:45:15 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-07-12 01:09:04 +0200 |
| commit | 2b29ac252afff87b8465b064ca2d9740cf1f6e52 (patch) | |
| tree | 9f4930db68ace50adc7c11feba12aafe34e2cdbe /fs/sysfs/sysfs.h | |
| parent | sysfs: implement kobj_sysfs_assoc_lock (diff) | |
| download | linux-2b29ac252afff87b8465b064ca2d9740cf1f6e52.tar.xz linux-2b29ac252afff87b8465b064ca2d9740cf1f6e52.zip | |
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 <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs/sysfs/sysfs.h')
| -rw-r--r-- | fs/sysfs/sysfs.h | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 718e2e123fae..60717660ac55 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); |