ovl: opaque cleanup

oe->opaque is set for

 a) whiteouts
 b) directories having the "trusted.overlay.opaque" xattr

Case b can be simplified, since setting the xattr always implies setting
oe->opaque.  Also once set, the opaque flag is never cleared.

Don't need to set opaque flag for non-directories.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

4 files changed, 25 insertions, 31 deletions

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index e191c631b17f..6c3aaf45e9cf 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -303,12 +303,6 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
         ovl_dentry_update(dentry, newdentry);
         ovl_inode_update(d_inode(dentry), d_inode(newdentry));
         newdentry = NULL;
-
-        /*
-         * Non-directores become opaque when copied up.
-         */
-        if (!S_ISDIR(stat->mode))
-                ovl_dentry_set_opaque(dentry, true);
 out2:
         dput(upper);
 out1:
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index b84d61b353cd..76e39aaaa038 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -128,9 +128,15 @@ int ovl_create_real(struct inode *dir, struct dentry *newdentry,
         return err;
 }
 
-static int ovl_set_opaque(struct dentry *upperdentry)
+static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)
 {
-        return ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0);
+        int err;
+
+        err = ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0);
+        if (!err)
+                ovl_dentry_set_opaque(dentry);
+
+        return err;
 }
 
 static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
@@ -274,7 +280,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
         if (err)
                 goto out_cleanup;
 
-        err = ovl_set_opaque(opaquedir);
+        err = ovl_set_opaque(dentry, opaquedir);
         if (err)
                 goto out_cleanup;
 
@@ -435,7 +441,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
         }
 
         if (!hardlink && S_ISDIR(stat->mode)) {
-                err = ovl_set_opaque(newdentry);
+                err = ovl_set_opaque(dentry, newdentry);
                 if (err)
                         goto out_cleanup;
 
@@ -996,29 +1002,22 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
         if (WARN_ON(olddentry->d_inode == newdentry->d_inode))
                 goto out_dput;
 
+        err = 0;
         if (is_dir) {
-                if (ovl_type_merge_or_lower(old)) {
+                if (ovl_type_merge_or_lower(old))
                         err = ovl_set_redirect(old, samedir);
-                        if (err)
-                                goto out_dput;
-                } else if (!old_opaque && ovl_lower_positive(new)) {
-                        err = ovl_set_opaque(olddentry);
-                        if (err)
-                                goto out_dput;
-                        ovl_dentry_set_opaque(old, true);
-                }
+                else if (!old_opaque && ovl_lower_positive(new))
+                        err = ovl_set_opaque(old, olddentry);
+                if (err)
+                        goto out_dput;
         }
         if (!overwrite && new_is_dir) {
-                if (ovl_type_merge_or_lower(new)) {
+                if (ovl_type_merge_or_lower(new))
                         err = ovl_set_redirect(new, samedir);
-                        if (err)
-                                goto out_dput;
-                } else if (!new_opaque && ovl_lower_positive(old)) {
-                        err = ovl_set_opaque(newdentry);
-                        if (err)
-                                goto out_dput;
-                        ovl_dentry_set_opaque(new, true);
-                }
+                else if (!new_opaque && ovl_lower_positive(old))
+                        err = ovl_set_opaque(new, newdentry);
+                if (err)
+                        goto out_dput;
         }
 
         err = ovl_do_rename(old_upperdir->d_inode, olddentry,
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index bdda37fa3f67..a83de5d5b8a0 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -156,7 +156,7 @@ struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
 bool ovl_dentry_is_opaque(struct dentry *dentry);
 bool ovl_dentry_is_whiteout(struct dentry *dentry);
-void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque);
+void ovl_dentry_set_opaque(struct dentry *dentry);
 bool ovl_redirect_dir(struct super_block *sb);
 void ovl_clear_redirect_dir(struct super_block *sb);
 const char *ovl_dentry_get_redirect(struct dentry *dentry);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 260b215852a3..952286f4826c 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -170,10 +170,11 @@ bool ovl_dentry_is_whiteout(struct dentry *dentry)
         return !dentry->d_inode && ovl_dentry_is_opaque(dentry);
 }
 
-void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque)
+void ovl_dentry_set_opaque(struct dentry *dentry)
 {
         struct ovl_entry *oe = dentry->d_fsdata;
-        oe->opaque = opaque;
+
+        oe->opaque = true;
 }
 
 bool ovl_redirect_dir(struct super_block *sb)