DAOS-16863 dfs: disallow force removal of entries with caching (#15570)

if a dfs sys mount has caching enabled, disable force removal of dir that does not check for child entries. DFS sys does not evict them from the cache in that case and that can cause namespace corruptions.

Signed-off-by: Mohamad Chaarawi <[email protected]>

src/client/dfs/dfs_sys.c

@@ -1318,6 +1318,12 @@ dfs_sys_remove_type(dfs_sys_t *dfs_sys, const char *path, bool force,
 		return EINVAL;
 	if (path == NULL)
 		return EINVAL;
+	/*
+	 * since we are not evicting child entries from the dfs sys cache in case of force removal
+	 * of a dir, just disallow force removal if cache is enabled on the dfs sys mount.
+	 */
+	if (dfs_sys->hash && force)
+		return ENOTSUP;
 
 	rc = sys_path_parse(dfs_sys, &sys_path, path);
 	if (rc != 0)

src/tests/suite/dfs_sys_unit_test.c

@@ -170,6 +170,12 @@ dfs_sys_test_create_remove(void **state)
 	rc = dfs_sys_symlink(dfs_sys_mt, sym1_target, sym1);
 	assert_int_equal(rc, 0);
 
+	/** remove should return ENOTSUP with force since caching is enabled */
+	rc = dfs_sys_remove(dfs_sys_mt, dir1, true, NULL);
+	assert_int_equal(rc, ENOTSUP);
+	rc = dfs_sys_remove_type(dfs_sys_mt, dir1, true, S_IFDIR, NULL);
+	assert_int_equal(rc, ENOTSUP);
+
 	/** Remove dirs, links with remove */
 	rc = dfs_sys_remove(dfs_sys_mt, sym1, 0, 0);
 	assert_int_equal(rc, 0);
@@ -212,20 +218,18 @@ dfs_sys_test_create_remove(void **state)
 	rc = dfs_sys_close(obj);
 	assert_int_equal(rc, 0);
 
-	/** Remove files with remove */
-	rc = dfs_sys_remove(dfs_sys_mt, file2, 0, 0);
-	assert_int_equal(rc, 0);
-
 	/** Remove dirs, files, links with remove_type */
 	rc = dfs_sys_remove_type(dfs_sys_mt, file1, false, S_IFREG, NULL);
 	assert_int_equal(rc, 0);
+	rc = dfs_sys_remove_type(dfs_sys_mt, file2, false, S_IFREG, NULL);
+	assert_int_equal(rc, 0);
 	rc = dfs_sys_remove_type(dfs_sys_mt, sym1, false, S_IFLNK, NULL);
 	assert_int_equal(rc, 0);
 	rc = dfs_sys_remove_type(dfs_sys_mt, dir3, false, S_IFDIR, NULL);
 	assert_int_equal(rc, 0);
-
-	/** Remove dirs with remove_type(force) */
-	rc = dfs_sys_remove_type(dfs_sys_mt, dir1, true, S_IFDIR, NULL);
+	rc = dfs_sys_remove_type(dfs_sys_mt, dir2, false, S_IFDIR, NULL);
+	assert_int_equal(rc, 0);
+	rc = dfs_sys_remove_type(dfs_sys_mt, dir1, false, S_IFDIR, NULL);
 	assert_int_equal(rc, 0);
 
 	/** Create dirs, files with mknod */
@@ -242,8 +246,14 @@ dfs_sys_test_create_remove(void **state)
 			   0, 0);
 	assert_int_equal(rc, 0);
 
-	/** Remove tree (dir) with remove(force) */
-	rc = dfs_sys_remove(dfs_sys_mt, dir1, true, NULL);
+	/** Remove tree with remove */
+	rc = dfs_sys_remove(dfs_sys_mt, file1, false, NULL);
+	assert_int_equal(rc, 0);
+	rc = dfs_sys_remove(dfs_sys_mt, dir3, false, NULL);
+	assert_int_equal(rc, 0);
+	rc = dfs_sys_remove(dfs_sys_mt, dir2, false, NULL);
+	assert_int_equal(rc, 0);
+	rc = dfs_sys_remove(dfs_sys_mt, dir1, false, NULL);
 	assert_int_equal(rc, 0);
 }
 
@@ -640,7 +650,14 @@ dfs_sys_test_open_readdir(void **state)
 	rc = dfs_sys_closedir(dirp);
 	assert_int_equal(rc, 0);
 
-	rc = dfs_sys_remove(dfs_sys_mt, dir1, true, NULL);
+	for (i = 0; i < num_dirs; i++) {
+		rc = snprintf(buf, buf_size, "%s/sub%u", dir1, i);
+		assert_true(rc > 0);
+		rc = dfs_sys_remove(dfs_sys_mt, buf, false, 0);
+		assert_int_equal(rc, 0);
+	}
+	rc = dfs_sys_remove(dfs_sys_mt, dir1, false, NULL);
+	assert_int_equal(rc, 0);
 }
 
 /**
@@ -848,11 +865,11 @@ dfs_sys_test_mkdir(void **state)
 	rc = dfs_sys_mkdir(dfs_sys_mt, file, S_IWUSR | S_IRUSR, 0);
 	assert_int_equal(rc, EEXIST);
 
-	rc = dfs_sys_remove(dfs_sys_mt, file, true, NULL);
+	rc = dfs_sys_remove(dfs_sys_mt, file, false, NULL);
 	assert_int_equal(rc, 0);
-	rc = dfs_sys_remove(dfs_sys_mt, child, true, NULL);
+	rc = dfs_sys_remove(dfs_sys_mt, child, false, NULL);
 	assert_int_equal(rc, 0);
-	rc = dfs_sys_remove(dfs_sys_mt, parent, true, NULL);
+	rc = dfs_sys_remove(dfs_sys_mt, parent, false, NULL);
 	assert_int_equal(rc, 0);
 }
 
@@ -885,11 +902,11 @@ dfs_sys_test_mkdir_p(void **state)
 	rc = dfs_sys_mkdir_p(dfs_sys_mt, file, S_IWUSR | S_IRUSR, 0);
 	assert_int_equal(rc, EEXIST);
 
-	rc = dfs_sys_remove(dfs_sys_mt, file, true, NULL);
+	rc = dfs_sys_remove(dfs_sys_mt, file, false, NULL);
 	assert_int_equal(rc, 0);
-	rc = dfs_sys_remove(dfs_sys_mt, child, true, NULL);
+	rc = dfs_sys_remove(dfs_sys_mt, child, false, NULL);
 	assert_int_equal(rc, 0);
-	rc = dfs_sys_remove(dfs_sys_mt, parent, true, NULL);
+	rc = dfs_sys_remove(dfs_sys_mt, parent, false, NULL);
 	assert_int_equal(rc, 0);
 }