ovl: create ovl_need_index() helper
The helper determines which lower file needs to be indexed
on copy up and before nlink changes.
For index=on, the helper evaluates to true for lower hardlinks.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 503c924..103e62d 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -536,11 +536,7 @@
{
int err;
struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info;
- bool indexed = false;
-
- if (ovl_indexdir(c->dentry->d_sb) && !S_ISDIR(c->stat.mode) &&
- c->stat.nlink > 1)
- indexed = true;
+ bool indexed = ovl_need_index(c->dentry);
if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || indexed)
c->origin = true;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 25794a3..d7e6528 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -241,6 +241,7 @@
bool ovl_test_flag(unsigned long flag, struct inode *inode);
bool ovl_inuse_trylock(struct dentry *dentry);
void ovl_inuse_unlock(struct dentry *dentry);
+bool ovl_need_index(struct dentry *dentry);
int ovl_nlink_start(struct dentry *dentry, bool *locked);
void ovl_nlink_end(struct dentry *dentry, bool locked);
int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index ae81d87..55ab991 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -463,6 +463,23 @@
}
}
+/*
+ * Does this overlay dentry need to be indexed on copy up?
+ */
+bool ovl_need_index(struct dentry *dentry)
+{
+ struct dentry *lower = ovl_dentry_lower(dentry);
+
+ if (!lower || !ovl_indexdir(dentry->d_sb))
+ return false;
+
+ /* Index only lower hardlinks on copy up */
+ if (!d_is_dir(lower) && d_inode(lower)->i_nlink > 1)
+ return true;
+
+ return false;
+}
+
/* Caller must hold OVL_I(inode)->lock */
static void ovl_cleanup_index(struct dentry *dentry)
{
@@ -533,11 +550,11 @@
/*
* With inodes index is enabled, we store the union overlay nlink
- * in an xattr on the index inode. When whiting out lower hardlinks
+ * in an xattr on the index inode. When whiting out an indexed lower,
* we need to decrement the overlay persistent nlink, but before the
* first copy up, we have no upper index inode to store the xattr.
*
- * As a workaround, before whiteout/rename over of a lower hardlink,
+ * As a workaround, before whiteout/rename over an indexed lower,
* copy up to create the upper index. Creating the upper index will
* initialize the overlay nlink, so it could be dropped if unlink
* or rename succeeds.
@@ -545,8 +562,7 @@
* TODO: implement metadata only index copy up when called with
* ovl_copy_up_flags(dentry, O_PATH).
*/
- if (ovl_indexdir(dentry->d_sb) && !ovl_dentry_has_upper_alias(dentry) &&
- d_inode(ovl_dentry_lower(dentry))->i_nlink > 1) {
+ if (ovl_need_index(dentry) && !ovl_dentry_has_upper_alias(dentry)) {
err = ovl_copy_up(dentry);
if (err)
return err;