ovl: handle rename when upper doesn't support xattr

On failure to set opaque/redirect xattr on rename, skip setting xattr and
return -EXDEV.

On failure to set opaque xattr when creating a new directory, -EIO is
returned instead of -EOPNOTSUPP.

Any failure to set those xattr will be recorded in super block and
then setting any xattr on upper won't be attempted again.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

3 files changed, 20 insertions, 19 deletions

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 723b98b90698..80e0e202a346 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -127,17 +127,28 @@ int ovl_create_real(struct inode *dir, struct dentry *newdentry,
         return err;
 }
 
-static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)
+static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper,
+                               int xerr)
 {
         int err;
 
-        err = ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0);
+        err = ovl_check_setxattr(dentry, upper, OVL_XATTR_OPAQUE, "y", 1, xerr);
         if (!err)
                 ovl_dentry_set_opaque(dentry);
 
         return err;
 }
 
+static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)
+{
+        /*
+         * Fail with -EIO when trying to create opaque dir and upper doesn't
+         * support xattrs. ovl_rename() calls ovl_set_opaque_xerr(-EXDEV) to
+         * return a specific error for noxattr case.
+         */
+        return ovl_set_opaque_xerr(dentry, upperdentry, -EIO);
+}
+
 /* Common operations required to be done after creation of file on upper */
 static void ovl_instantiate(struct dentry *dentry, struct inode *inode,
                             struct dentry *newdentry, bool hardlink)
@@ -846,18 +857,16 @@ static int ovl_set_redirect(struct dentry *dentry, bool samedir)
         if (IS_ERR(redirect))
                 return PTR_ERR(redirect);
 
-        err = ovl_do_setxattr(ovl_dentry_upper(dentry), OVL_XATTR_REDIRECT,
-                              redirect, strlen(redirect), 0);
+        err = ovl_check_setxattr(dentry, ovl_dentry_upper(dentry),
+                                 OVL_XATTR_REDIRECT,
+                                 redirect, strlen(redirect), -EXDEV);
         if (!err) {
                 spin_lock(&dentry->d_lock);
                 ovl_dentry_set_redirect(dentry, redirect);
                 spin_unlock(&dentry->d_lock);
         } else {
                 kfree(redirect);
-                if (err == -EOPNOTSUPP)
-                        ovl_clear_redirect_dir(dentry->d_sb);
-                else
-                        pr_warn_ratelimited("overlay: failed to set redirect (%i)\n", err);
+                pr_warn_ratelimited("overlay: failed to set redirect (%i)\n", err);
                 /* Fall back to userspace copy-up */
                 err = -EXDEV;
         }
@@ -992,7 +1001,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
                 if (ovl_type_merge_or_lower(old))
                         err = ovl_set_redirect(old, samedir);
                 else if (!old_opaque && ovl_type_merge(new->d_parent))
-                        err = ovl_set_opaque(old, olddentry);
+                        err = ovl_set_opaque_xerr(old, olddentry, -EXDEV);
                 if (err)
                         goto out_dput;
         }
@@ -1000,7 +1009,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
                 if (ovl_type_merge_or_lower(new))
                         err = ovl_set_redirect(new, samedir);
                 else if (!new_opaque && ovl_type_merge(old->d_parent))
-                        err = ovl_set_opaque(new, newdentry);
+                        err = ovl_set_opaque_xerr(new, newdentry, -EXDEV);
                 if (err)
                         goto out_dput;
         }
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index ce7c3aba61e4..505b18b56330 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -206,7 +206,6 @@ 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 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);
 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index b5a0dc36ee96..4d541a8d0834 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -191,14 +191,7 @@ 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;
+        return ofs->config.redirect_dir && !ofs->noxattr;
 }
 
 const char *ovl_dentry_get_redirect(struct dentry *dentry)