ovl: check for emptiness of redirect dir (d1595119) · Commits · 戴 / test

Before introducing redirect_dir feature, the condition !ovl_lower_positive(dentry) for a directory, implied that it is a pure upper directory, which may be removed if empty. Now that directory can be redirect, it is possible that upper does not cover any lower (i.e. !ovl_lower_positive(dentry)), but the directory is a merge (with redirected path) and maybe non empty. Check for this case in ovl_remove_upper(). This change fixes the following test case from rename-pop-dir.py of unionmount-testsuite: """Remove dir and rename old name""" d = ctx.non_empty_dir() d2 = ctx.no_dir() ctx.rmdir(d, err=ENOTEMPTY) ctx.rename(d, d2) ctx.rmdir(d, err=ENOENT) ctx.rmdir(d2, err=ENOTEMPTY) ./run --ov rename-pop-dir /mnt/a/no_dir103: Expected error (Directory not empty) was not produced Signed-off-by:

Amir Goldstein <amir73il@gmail.com> Signed-off-by:

Miklos Szeredi <mszeredi@redhat.com>

fs/overlayfs/dir.c

+22 −9

Original line number	Diff line number	Diff line
		@@ -674,8 +674,17 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
		struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
		struct inode *dir = upperdir->d_inode;
		struct dentry *upper;
		struct dentry *opaquedir = NULL;
		int err;

		/* Redirect dir can be !ovl_lower_positive && OVL_TYPE_MERGE */
		if (is_dir && ovl_dentry_get_redirect(dentry)) {
		opaquedir = ovl_check_empty_and_clear(dentry);
		err = PTR_ERR(opaquedir);
		if (IS_ERR(opaquedir))
		goto out;
		}

		inode_lock_nested(dir, I_MUTEX_PARENT);
		upper = lookup_one_len(dentry->d_name.name, upperdir,
		dentry->d_name.len);
		@@ -684,14 +693,15 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
		goto out_unlock;

		err = -ESTALE;
		if (upper == ovl_dentry_upper(dentry)) {
		if ((opaquedir && upper != opaquedir) \|\|
		(!opaquedir && upper != ovl_dentry_upper(dentry)))
		goto out_dput_upper;

		if (is_dir)
		err = vfs_rmdir(dir, upper);
		else
		err = vfs_unlink(dir, upper, NULL);
		ovl_dentry_version_inc(dentry->d_parent);
		}
		dput(upper);

		/*
		* Keeping this dentry hashed would mean having to release
		@@ -701,9 +711,12 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
		*/
		if (!err)
		d_drop(dentry);
		out_dput_upper:
		dput(upper);
		out_unlock:
		inode_unlock(dir);

		dput(opaquedir);
		out:
		return err;
		}

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