[PATCH 30/74] union-mount: Create d_free_unions()
From: Valerie Aurora <hidden>
Date: 2011-03-23 02:01:41
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
From: Valerie Aurora <redacted> d_free_unions() frees the union stack associated with a directory. Signed-off-by: Valerie Aurora <redacted> --- fs/union.c | 25 +++++++++++++++++++++++++ fs/union.h | 7 +++++++ 2 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/fs/union.c b/fs/union.c
index 52a5c28..a191bef 100644
--- a/fs/union.c
+++ b/fs/union.c@@ -21,6 +21,7 @@ #include <linux/mount.h> #include <linux/fs_struct.h> #include <linux/slab.h> +#include <linux/namei.h> #include "union.h"
@@ -40,3 +41,27 @@ static struct union_stack *union_alloc(struct path *topmost) return kzalloc(sizeof(struct path) * layers, GFP_KERNEL); } + +/** + * d_free_unions - free all unions for this dentry + * + * @dentry - topmost dentry in the union stack to remove + * + * This must be called when freeing a dentry. + */ +void d_free_unions(struct dentry *topmost) +{ + struct path *path; + unsigned int i, layers = topmost->d_sb->s_union_count; + + if (!IS_DIR_UNIONED(topmost)) + return; + + for (i = 0; i < layers; i++) { + path = union_find_dir(topmost, i); + if (path->mnt) + path_put(path); + } + kfree(topmost->d_union_stack); + topmost->d_union_stack = NULL; +}
diff --git a/fs/union.h b/fs/union.h
index e242451..353f78d 100644
--- a/fs/union.h
+++ b/fs/union.h@@ -49,6 +49,10 @@ struct union_stack { struct path u_dirs[0]; }; +#define IS_DIR_UNIONED(dentry) ((dentry)->d_union_stack) + +extern void d_free_unions(struct dentry *); + static inline struct path *union_find_dir(struct dentry *dentry, unsigned int layer) { BUG_ON(layer >= dentry->d_sb->s_union_count);
@@ -57,6 +61,9 @@ static inline struct path *union_find_dir(struct dentry *dentry, #else /* CONFIG_UNION_MOUNT */ +#define IS_DIR_UNIONED(x) (0) + +#define d_free_unions(x) do { } while (0) #define union_find_dir(x, y) ({ BUG(); (NULL); }) #endif /* CONFIG_UNION_MOUNT */
--
1.7.0.4