Commit ac9bba03 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
Browse files

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: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cf9e5a73

fs/kernfs/dir.c

+5 −5
Original line number Diff line number Diff line
@@ -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);

fs/kernfs/symlink.c

+1 −1
Original line number Diff line number Diff line
@@ -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 */

fs/sysfs/symlink.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

include/linux/kernfs.h

+14 −0
Original line number Diff line number Diff line
@@ -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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE