From: Tejun Heo <tj@kernel.org>
To: gregkh@linuxfoundation.org
Cc: linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
kbuild test robot <fengguang.wu@intel.com>
Subject: [PATCH 08/10] kernfs: implement kernfs_node_from_dentry(), kernfs_root_from_sb() and kernfs_rename()
Date: Mon, 3 Feb 2014 14:09:15 -0500 [thread overview]
Message-ID: <1391454557-32376-9-git-send-email-tj@kernel.org> (raw)
In-Reply-To: <1391454557-32376-1-git-send-email-tj@kernel.org>
Implement helpers to determine node from dentry and root from
super_block. Also add a kernfs_rename_ns() wrapper which assumes NULL
namespace. These generally make sense and will be used by cgroup.
v2: Some dummy implementations for !CONFIG_SYSFS was missing. Fixed.
Reported by kbuild test robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
---
fs/kernfs/dir.c | 18 ++++++++++++++++++
fs/kernfs/mount.c | 14 ++++++++++++++
include/linux/kernfs.h | 16 ++++++++++++++++
3 files changed, 48 insertions(+)
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 3cff0a2..42a250f 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -350,6 +350,24 @@ const struct dentry_operations kernfs_dops = {
.d_release = kernfs_dop_release,
};
+/**
+ * kernfs_node_from_dentry - determine kernfs_node associated with a dentry
+ * @dentry: the dentry in question
+ *
+ * Return the kernfs_node associated with @dentry. If @dentry is not a
+ * kernfs one, %NULL is returned.
+ *
+ * While the returned kernfs_node will stay accessible as long as @dentry
+ * is accessible, the returned node can be in any state and the caller is
+ * fully responsible for determining what's accessible.
+ */
+struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry)
+{
+ if (dentry->d_op == &kernfs_dops)
+ return dentry->d_fsdata;
+ return NULL;
+}
+
static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
const char *name, umode_t mode,
unsigned flags)
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index 70cc698..e5b28b0 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -48,6 +48,20 @@ static const struct super_operations kernfs_sops = {
.show_options = kernfs_sop_show_options,
};
+/**
+ * kernfs_root_from_sb - determine kernfs_root associated with a super_block
+ * @sb: the super_block in question
+ *
+ * Return the kernfs_root associated with @sb. If @sb is not a kernfs one,
+ * %NULL is returned.
+ */
+struct kernfs_root *kernfs_root_from_sb(struct super_block *sb)
+{
+ if (sb->s_op == &kernfs_sops)
+ return kernfs_info(sb)->root;
+ return NULL;
+}
+
static int kernfs_fill_super(struct super_block *sb)
{
struct kernfs_super_info *info = kernfs_info(sb);
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 9ca0f09..9c89904 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -234,6 +234,9 @@ struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent,
void kernfs_get(struct kernfs_node *kn);
void kernfs_put(struct kernfs_node *kn);
+struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry);
+struct kernfs_root *kernfs_root_from_sb(struct super_block *sb);
+
struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops,
unsigned int flags, void *priv);
void kernfs_destroy_root(struct kernfs_root *root);
@@ -288,6 +291,12 @@ kernfs_find_and_get_ns(struct kernfs_node *parent, const char *name,
static inline void kernfs_get(struct kernfs_node *kn) { }
static inline void kernfs_put(struct kernfs_node *kn) { }
+static inline struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry)
+{ return NULL; }
+
+static inline struct kernfs_root *kernfs_root_from_sb(struct super_block *sb)
+{ return NULL; }
+
static inline struct kernfs_root *
kernfs_create_root(struct kernfs_syscall_ops *scops, unsigned int flags,
void *priv)
@@ -388,6 +397,13 @@ static inline int kernfs_remove_by_name(struct kernfs_node *parent,
return kernfs_remove_by_name_ns(parent, name, NULL);
}
+static inline int kernfs_rename(struct kernfs_node *kn,
+ struct kernfs_node *new_parent,
+ const char *new_name)
+{
+ return kernfs_rename_ns(kn, new_parent, new_name, NULL);
+}
+
static inline struct dentry *
kernfs_mount(struct file_system_type *fs_type, int flags,
struct kernfs_root *root)
--
1.8.5.3
next prev parent reply other threads:[~2014-02-03 19:09 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-03 19:09 [PATCHSET v2 driver-core-next] kernfs: prepare for cgroup's kernfs conversion Tejun Heo
2014-02-03 19:09 ` [PATCH 01/10] kernfs: invoke dir_ops while holding active ref of the target node Tejun Heo
2014-02-03 19:09 ` [PATCH 02/10] kernfs: rename kernfs_dir_ops to kernfs_syscall_ops Tejun Heo
2014-02-03 19:09 ` [PATCH 03/10] kernfs: implement kernfs_syscall_ops->remount_fs() and ->show_options() Tejun Heo
2014-02-03 19:09 ` [PATCH 04/10] kernfs: add missing kernfs_active() checks in directory operations Tejun Heo
2014-02-03 19:09 ` [PATCH 05/10] kernfs: allow nodes to be created in the deactivated state Tejun Heo
2014-02-03 19:09 ` [PATCH 06/10] kernfs: implement kernfs_ops->atomic_write_len Tejun Heo
2014-02-03 19:09 ` [PATCH 07/10] kernfs: add kernfs_open_file->priv Tejun Heo
2014-02-03 19:09 ` Tejun Heo [this message]
2014-02-03 19:09 ` [PATCH 09/10] kernfs: implement kernfs_get_parent(), kernfs_name/path() and friends Tejun Heo
2014-02-07 18:40 ` [PATCH v2 " Tejun Heo
2014-02-03 19:09 ` [PATCH 10/10] kernfs: add CONFIG_KERNFS Tejun Heo
2014-02-07 18:41 ` [PATCH 9.5/10] sysfs, kobject: add sysfs wrapper for kernfs_enable_ns() Tejun Heo
2014-02-07 18:43 ` [PATCHSET v2 driver-core-next] kernfs: prepare for cgroup's kernfs conversion Tejun Heo
2014-02-08 0:12 ` Greg KH
2014-02-08 15:07 ` Tejun Heo
2014-02-08 15:08 ` Tejun Heo
2014-02-08 18:17 ` Greg KH
2014-02-08 18:17 ` Tejun Heo
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