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authorMiklos Szeredi <mszeredi@redhat.com>2016-12-16 11:02:56 +0100
committerMiklos Szeredi <mszeredi@redhat.com>2016-12-16 11:02:56 +0100
commita6c6065511411c57167a6cdae0c33263fb662b51 (patch)
treecd2c7904884c557a0d7d26a88efc737a8885407a /fs/overlayfs/util.c
parent02b69b284cd7815239fabfe895bfef9a9eb5a3ce (diff)
ovl: redirect on rename-dir
Current code returns EXDEV when a directory would need to be copied up to move. We could copy up the directory tree in this case, but there's another, simpler solution: point to old lower directory from moved upper directory. This is achieved with a "trusted.overlay.redirect" xattr storing the path relative to the root of the overlay. After such attribute has been set, the directory can be moved without further actions required. This is a backward incompatible feature, old kernels won't be able to correctly mount an overlay containing redirected directories. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/util.c')
-rw-r--r--fs/overlayfs/util.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 0d45a84468d2..260b215852a3 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -176,6 +176,35 @@ void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque)
oe->opaque = opaque;
}
+bool ovl_redirect_dir(struct super_block *sb)
+{
+ struct ovl_fs *ofs = sb->s_fs_info;
+
+ return ofs->config.redirect_dir;
+}
+
+void ovl_clear_redirect_dir(struct super_block *sb)
+{
+ struct ovl_fs *ofs = sb->s_fs_info;
+
+ ofs->config.redirect_dir = false;
+}
+
+const char *ovl_dentry_get_redirect(struct dentry *dentry)
+{
+ struct ovl_entry *oe = dentry->d_fsdata;
+
+ return oe->redirect;
+}
+
+void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect)
+{
+ struct ovl_entry *oe = dentry->d_fsdata;
+
+ kfree(oe->redirect);
+ oe->redirect = redirect;
+}
+
void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry)
{
struct ovl_entry *oe = dentry->d_fsdata;