118 lines
3.3 KiB
Diff
118 lines
3.3 KiB
Diff
--- a/fs/namespace.c
|
|
+++ b/fs/namespace.c
|
|
@@ -1656,8 +1656,10 @@ static int do_move_mount(struct path *pa
|
|
|
|
/* moving to or from a union mount is not supported */
|
|
err = -EINVAL;
|
|
+#if 0
|
|
if (IS_MNT_UNION(path->mnt))
|
|
goto exit;
|
|
+#endif
|
|
if (IS_MNT_UNION(old_path.mnt))
|
|
goto exit;
|
|
|
|
--- a/fs/union.c
|
|
+++ b/fs/union.c
|
|
@@ -260,8 +260,6 @@ int append_to_union(struct vfsmount *mnt
|
|
spin_lock(&union_lock);
|
|
um = union_lookup(dentry, mnt);
|
|
if (um) {
|
|
- BUG_ON((um->u_next.dentry != dest_dentry) ||
|
|
- (um->u_next.mnt != dest_mnt));
|
|
spin_unlock(&union_lock);
|
|
union_put(this);
|
|
return 0;
|
|
@@ -274,6 +272,23 @@ int append_to_union(struct vfsmount *mnt
|
|
return 0;
|
|
}
|
|
|
|
+int follow_union_mountpoint(struct path *path)
|
|
+{
|
|
+ struct path new_path = *path;
|
|
+
|
|
+ path_get(&new_path);
|
|
+ while (follow_union_down(&new_path)) {
|
|
+ if (new_path.dentry != new_path.mnt->mnt_root)
|
|
+ continue;
|
|
+
|
|
+ path_put(path);
|
|
+ *path = new_path;
|
|
+ return 1;
|
|
+ }
|
|
+ path_put(&new_path);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
/*
|
|
* follow_union_down - follow the union stack one layer down
|
|
*
|
|
--- a/include/linux/union.h
|
|
+++ b/include/linux/union.h
|
|
@@ -47,6 +47,7 @@ extern int append_to_union(struct vfsmou
|
|
struct vfsmount *, struct dentry *);
|
|
extern int follow_union_down(struct path *);
|
|
extern int follow_union_mount(struct path *);
|
|
+extern int follow_union_mountpoint(struct path *path);
|
|
extern void __d_drop_unions(struct dentry *);
|
|
extern void shrink_d_unions(struct dentry *);
|
|
extern void __shrink_d_unions(struct dentry *, struct list_head *);
|
|
@@ -68,6 +69,7 @@ extern int union_permission(struct path
|
|
#define append_to_union(x1, y1, x2, y2) ({ BUG(); (0); })
|
|
#define follow_union_down(x) ({ (0); })
|
|
#define follow_union_mount(x) ({ (0); })
|
|
+#define follow_union_mountpoint(x) ({ (0); })
|
|
#define __d_drop_unions(x) do { } while (0)
|
|
#define shrink_d_unions(x) do { } while (0)
|
|
#define __shrink_d_unions(x,y) do { } while (0)
|
|
--- a/fs/namei.c
|
|
+++ b/fs/namei.c
|
|
@@ -613,6 +613,9 @@ static int cache_lookup_union(struct nam
|
|
!S_ISDIR(path->dentry->d_inode->i_mode))
|
|
goto out;
|
|
|
|
+ if (follow_union_mountpoint(path))
|
|
+ goto out;
|
|
+
|
|
/* Build the union stack for this part */
|
|
res = __cache_lookup_build_union(nd, name, path);
|
|
if (res) {
|
|
@@ -886,6 +889,9 @@ static int real_lookup_union(struct name
|
|
!S_ISDIR(path->dentry->d_inode->i_mode))
|
|
goto out;
|
|
|
|
+ if (follow_union_mountpoint(path))
|
|
+ goto out;
|
|
+
|
|
/* Build the union stack for this part */
|
|
res = __real_lookup_build_union(nd, name, path);
|
|
if (res) {
|
|
@@ -1813,6 +1819,9 @@ int hash_lookup_union(struct nameidata *
|
|
!S_ISDIR(path->dentry->d_inode->i_mode))
|
|
goto out;
|
|
|
|
+ if (follow_union_mountpoint(path))
|
|
+ goto out;
|
|
+
|
|
/* Build the union stack for this part */
|
|
res = __hash_lookup_build_union(nd, name, path);
|
|
if (res) {
|
|
--- a/fs/readdir.c
|
|
+++ b/fs/readdir.c
|
|
@@ -17,6 +17,7 @@
|
|
#include <linux/syscalls.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/union.h>
|
|
+#include <linux/mount.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
|
|
@@ -45,7 +46,7 @@ int vfs_readdir(struct file *file, filld
|
|
* below this one in the union stack.
|
|
*/
|
|
if (is_unionized(file->f_path.dentry, file->f_path.mnt) &&
|
|
- !IS_OPAQUE(inode)) {
|
|
+ !IS_OPAQUE(inode) && IS_MNT_UNION(file->f_path.mnt)) {
|
|
res = union_copyup_dir(&file->f_path);
|
|
if (res)
|
|
goto out_unlock;
|