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authorTejun Heo <tj@kernel.org>2013-11-30 02:19:09 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-30 06:41:28 +0400
commitac9bba031001704a2339713cc12148857eccc5e5 (patch)
treec058217a47c51021d97454639ed0f7480c73fe6a
parentcf9e5a73aaff0204801dd19cb4bd91d32f32026a (diff)
downloadlinux-ac9bba031001704a2339713cc12148857eccc5e5.tar.xz
sysfs, kernfs: implement kernfs_ns_enabled()
fs/sysfs/symlink.c::sysfs_delete_link() tests @sd->s_flags for SYSFS_FLAG_NS. Let's add kernfs_ns_enabled() so that sysfs doesn't have to test sysfs_dirent flag directly. This makes things tidier for kernfs proper too. This is purely cosmetic. v2: To avoid possible NULL deref, use noop dummy implementation which always returns false when !CONFIG_SYSFS. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/kernfs/dir.c10
-rw-r--r--fs/kernfs/symlink.c2
-rw-r--r--fs/sysfs/symlink.c2
-rw-r--r--include/linux/kernfs.h14
4 files changed, 21 insertions, 7 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 7c5b51793689..f51e0625e666 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -291,7 +291,7 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
goto out_bad;
/* The sysfs dirent has been moved to a different namespace */
- if (sd->s_parent && (sd->s_parent->s_flags & SYSFS_FLAG_NS) &&
+ if (sd->s_parent && kernfs_ns_enabled(sd->s_parent) &&
sysfs_info(dentry->d_sb)->ns != sd->s_ns)
goto out_bad;
@@ -414,7 +414,7 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt)
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
struct sysfs_dirent *parent_sd)
{
- bool has_ns = parent_sd->s_flags & SYSFS_FLAG_NS;
+ bool has_ns = kernfs_ns_enabled(parent_sd);
struct sysfs_inode_attrs *ps_iattr;
int ret;
@@ -535,7 +535,7 @@ static struct sysfs_dirent *kernfs_find_ns(struct sysfs_dirent *parent,
const void *ns)
{
struct rb_node *node = parent->s_dir.children.rb_node;
- bool has_ns = parent->s_flags & SYSFS_FLAG_NS;
+ bool has_ns = kernfs_ns_enabled(parent);
unsigned int hash;
lockdep_assert_held(&sysfs_mutex);
@@ -685,7 +685,7 @@ static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry,
mutex_lock(&sysfs_mutex);
- if (parent_sd->s_flags & SYSFS_FLAG_NS)
+ if (kernfs_ns_enabled(parent_sd))
ns = sysfs_info(dir->i_sb)->ns;
sd = kernfs_find_ns(parent_sd, dentry->d_name.name, ns);
@@ -968,7 +968,7 @@ static int sysfs_readdir(struct file *file, struct dir_context *ctx)
return 0;
mutex_lock(&sysfs_mutex);
- if (parent_sd->s_flags & SYSFS_FLAG_NS)
+ if (kernfs_ns_enabled(parent_sd))
ns = sysfs_info(dentry->d_sb)->ns;
for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos);
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index 004c16465594..12569a738837 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -35,7 +35,7 @@ struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
if (!sd)
return ERR_PTR(-ENOMEM);
- if (parent->s_flags & SYSFS_FLAG_NS)
+ if (kernfs_ns_enabled(parent))
sd->s_ns = target->s_ns;
sd->s_symlink.target_sd = target;
kernfs_get(target); /* ref owned by symlink */
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 62f0e014ec48..1b8c9ed8511a 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -128,7 +128,7 @@ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
* sysfs_remove_dir() for details.
*/
spin_lock(&sysfs_symlink_target_lock);
- if (targ->sd && (kobj->sd->s_flags & SYSFS_FLAG_NS))
+ if (targ->sd && kernfs_ns_enabled(kobj->sd))
ns = targ->sd->s_ns;
spin_unlock(&sysfs_symlink_target_lock);
kernfs_remove_by_name_ns(kobj->sd, name, ns);
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index faaf4f29e33d..d65541308419 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -190,6 +190,17 @@ static inline void kernfs_enable_ns(struct sysfs_dirent *sd)
sd->s_flags |= SYSFS_FLAG_NS;
}
+/**
+ * kernfs_ns_enabled - test whether namespace is enabled
+ * @sd: the node to test
+ *
+ * Test whether namespace filtering is enabled for the children of @ns.
+ */
+static inline bool kernfs_ns_enabled(struct sysfs_dirent *sd)
+{
+ return sd->s_flags & SYSFS_FLAG_NS;
+}
+
struct sysfs_dirent *kernfs_find_and_get_ns(struct sysfs_dirent *parent,
const char *name, const void *ns);
void kernfs_get(struct sysfs_dirent *sd);
@@ -232,6 +243,9 @@ static inline enum kernfs_node_type sysfs_type(struct sysfs_dirent *sd)
static inline void kernfs_enable_ns(struct sysfs_dirent *sd) { }
+static inline bool kernfs_ns_enabled(struct sysfs_dirent *sd)
+{ return false; }
+
static inline struct sysfs_dirent *
kernfs_find_and_get_ns(struct sysfs_dirent *parent, const char *name,
const void *ns)