From ac9bba031001704a2339713cc12148857eccc5e5 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 29 Nov 2013 17:19:09 -0500 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/dir.c | 10 +++++----- fs/kernfs/symlink.c | 2 +- fs/sysfs/symlink.c | 2 +- include/linux/kernfs.h | 14 ++++++++++++++ 4 files changed, 21 insertions(+), 7 deletions(-) diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 7c5b517..f51e062 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 004c164..12569a7 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 62f0e01..1b8c9ed 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 faaf4f2..d655413 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) -- 2.7.4