[PATCH 03/10 v7] path: New helpers path_get_pin/path_put_unpin for path pin

Kinglong Mee
2015-07-11T12:48:18Z

Two helpers for filesystem pining to vfsmnt, not mntget.

v4, v5, v6, v7 same as v2.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
---
fs/namei.c | 26 ++++++++++++++++++++++++++
include/linux/path.h | 4 ++++
2 files changed, 30 insertions(+)

diff --git a/fs/namei.c b/fs/namei.c
index ae4e4c1..08f2cfc 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -492,6 +492,32 @@ void path_put(const struct path *path)
}
EXPORT_SYMBOL(path_put);

+/**
+ * path_get_pin - get a reference to a path's dentry
+ * and pin to path's vfsmnt
+ * @path: path to get the reference to
+ * @p: the fs_pin pin to vfsmnt
+ */
+void path_get_pin(struct path *path, struct fs_pin *p)
+{
+ dget(path->dentry);
+ pin_insert_group(p, path->mnt, NULL);
+}
+EXPORT_SYMBOL(path_get_pin);
+
+/**
+ * path_put_unpin - put a reference to a path's dentry
+ * and remove pin to path's vfsmnt
+ * @path: path to put the reference to
+ * @p: the fs_pin removed from vfsmnt
+ */
+void path_put_unpin(struct path *path, struct fs_pin *p)
+{
+ dput(path->dentry);
+ pin_remove(p);
+}
+EXPORT_SYMBOL(path_put_unpin);
+
#define EMBEDDED_LEVELS 2
struct nameidata {
struct path path;
diff --git a/include/linux/path.h b/include/linux/path.h
index d137218..34599fb 100644
--- a/include/linux/path.h
+++ b/include/linux/path.h
@@ -3,6 +3,7 @@

struct dentry;
struct vfsmount;
+struct fs_pin;

struct path {
struct vfsmount *mnt;
@@ -12,6 +13,9 @@ struct path {
extern void path_get(const struct path *);
extern void path_put(const struct path *);

+extern void path_get_pin(struct path *, struct fs_pin *);
+extern void path_put_unpin(struct path *, struct fs_pin *);
+
static inline int path_equal(const struct path *path1, const struct path *path2)
{
return path1->mnt == path2->mnt && path1->dentry == path2->dentry;
--
2.4.3