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-rw-r--r--fs/kernfs/dir.c2
-rw-r--r--fs/kernfs/kernfs-internal.h19
-rw-r--r--include/linux/kernfs.h5
3 files changed, 26 insertions, 0 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 33166ec90a11..b3d1bc0f317d 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -372,6 +372,7 @@ static int kernfs_link_sibling(struct kernfs_node *kn)
/* successfully added, account subdir number */
if (kernfs_type(kn) == KERNFS_DIR)
kn->parent->dir.subdirs++;
+ kernfs_inc_rev(kn->parent);
return 0;
}
@@ -394,6 +395,7 @@ static bool kernfs_unlink_sibling(struct kernfs_node *kn)
if (kernfs_type(kn) == KERNFS_DIR)
kn->parent->dir.subdirs--;
+ kernfs_inc_rev(kn->parent);
rb_erase(&kn->rb, &kn->parent->dir.children);
RB_CLEAR_NODE(&kn->rb);
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index ccc3b44f6306..c2ae58f3b202 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -81,6 +81,25 @@ static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
return d_inode(dentry)->i_private;
}
+static inline void kernfs_set_rev(struct kernfs_node *parent,
+ struct dentry *dentry)
+{
+ dentry->d_time = parent->dir.rev;
+}
+
+static inline void kernfs_inc_rev(struct kernfs_node *parent)
+{
+ parent->dir.rev++;
+}
+
+static inline bool kernfs_dir_changed(struct kernfs_node *parent,
+ struct dentry *dentry)
+{
+ if (parent->dir.rev != dentry->d_time)
+ return true;
+ return false;
+}
+
extern const struct super_operations kernfs_sops;
extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 9e8ca8743c26..d68b4ad09573 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -98,6 +98,11 @@ struct kernfs_elem_dir {
* better directly in kernfs_node but is here to save space.
*/
struct kernfs_root *root;
+ /*
+ * Monotonic revision counter, used to identify if a directory
+ * node has changed during negative dentry revalidation.
+ */
+ unsigned long rev;
};
struct kernfs_elem_symlink {