Commit ac9bba03 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
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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
...@@ -291,7 +291,7 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags) ...@@ -291,7 +291,7 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
goto out_bad; goto out_bad;
/* The sysfs dirent has been moved to a different namespace */ /* 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) sysfs_info(dentry->d_sb)->ns != sd->s_ns)
goto out_bad; goto out_bad;
...@@ -414,7 +414,7 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt) ...@@ -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, int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
struct sysfs_dirent *parent_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; struct sysfs_inode_attrs *ps_iattr;
int ret; int ret;
...@@ -535,7 +535,7 @@ static struct sysfs_dirent *kernfs_find_ns(struct sysfs_dirent *parent, ...@@ -535,7 +535,7 @@ static struct sysfs_dirent *kernfs_find_ns(struct sysfs_dirent *parent,
const void *ns) const void *ns)
{ {
struct rb_node *node = parent->s_dir.children.rb_node; 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; unsigned int hash;
lockdep_assert_held(&sysfs_mutex); lockdep_assert_held(&sysfs_mutex);
...@@ -685,7 +685,7 @@ static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry, ...@@ -685,7 +685,7 @@ static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry,
mutex_lock(&sysfs_mutex); 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; ns = sysfs_info(dir->i_sb)->ns;
sd = kernfs_find_ns(parent_sd, dentry->d_name.name, 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) ...@@ -968,7 +968,7 @@ static int sysfs_readdir(struct file *file, struct dir_context *ctx)
return 0; return 0;
mutex_lock(&sysfs_mutex); 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; ns = sysfs_info(dentry->d_sb)->ns;
for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos); for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos);
......
...@@ -35,7 +35,7 @@ struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent, ...@@ -35,7 +35,7 @@ struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
if (!sd) if (!sd)
return ERR_PTR(-ENOMEM); return ERR_PTR(-ENOMEM);
if (parent->s_flags & SYSFS_FLAG_NS) if (kernfs_ns_enabled(parent))
sd->s_ns = target->s_ns; sd->s_ns = target->s_ns;
sd->s_symlink.target_sd = target; sd->s_symlink.target_sd = target;
kernfs_get(target); /* ref owned by symlink */ kernfs_get(target); /* ref owned by symlink */
......
...@@ -128,7 +128,7 @@ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ, ...@@ -128,7 +128,7 @@ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
* sysfs_remove_dir() for details. * sysfs_remove_dir() for details.
*/ */
spin_lock(&sysfs_symlink_target_lock); 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; ns = targ->sd->s_ns;
spin_unlock(&sysfs_symlink_target_lock); spin_unlock(&sysfs_symlink_target_lock);
kernfs_remove_by_name_ns(kobj->sd, name, ns); kernfs_remove_by_name_ns(kobj->sd, name, ns);
......
...@@ -190,6 +190,17 @@ static inline void kernfs_enable_ns(struct sysfs_dirent *sd) ...@@ -190,6 +190,17 @@ static inline void kernfs_enable_ns(struct sysfs_dirent *sd)
sd->s_flags |= SYSFS_FLAG_NS; 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, struct sysfs_dirent *kernfs_find_and_get_ns(struct sysfs_dirent *parent,
const char *name, const void *ns); const char *name, const void *ns);
void kernfs_get(struct sysfs_dirent *sd); void kernfs_get(struct sysfs_dirent *sd);
...@@ -232,6 +243,9 @@ static inline enum kernfs_node_type sysfs_type(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 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 * static inline struct sysfs_dirent *
kernfs_find_and_get_ns(struct sysfs_dirent *parent, const char *name, kernfs_find_and_get_ns(struct sysfs_dirent *parent, const char *name,
const void *ns) const void *ns)
......
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