diff --git a/tools/testing/selftests/filesystems/incfs/.gitignore b/tools/testing/selftests/filesystems/incfs/.gitignore
index 6b90110d6556..f0e3cd99d4ac 100644
--- a/tools/testing/selftests/filesystems/incfs/.gitignore
+++ b/tools/testing/selftests/filesystems/incfs/.gitignore
@@ -1,2 +1,3 @@
 incfs_test
 incfs_stress
+incfs_perf
diff --git a/tools/testing/selftests/filesystems/incfs/Makefile b/tools/testing/selftests/filesystems/incfs/Makefile
index 1484dbe8f7e1..882b43decbcd 100644
--- a/tools/testing/selftests/filesystems/incfs/Makefile
+++ b/tools/testing/selftests/filesystems/incfs/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 CFLAGS += -D_FILE_OFFSET_BITS=64 -Wall -I../.. -I../../../../..
 LDLIBS := -llz4 -lcrypto -lpthread
-TEST_GEN_PROGS := incfs_test incfs_stress
+TEST_GEN_PROGS := incfs_test incfs_stress incfs_perf
 
 include ../../lib.mk
 
diff --git a/tools/testing/selftests/filesystems/incfs/incfs_perf.c b/tools/testing/selftests/filesystems/incfs/incfs_perf.c
new file mode 100644
index 000000000000..ed36bbd774e3
--- /dev/null
+++ b/tools/testing/selftests/filesystems/incfs/incfs_perf.c
@@ -0,0 +1,717 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Google LLC
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <lz4.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <ctype.h>
+#include <unistd.h>
+
+#include "utils.h"
+
+#define err_msg(...)                                                           \
+	do {                                                                   \
+		fprintf(stderr, "%s: (%d) ", TAG, __LINE__);                   \
+		fprintf(stderr, __VA_ARGS__);                                  \
+		fprintf(stderr, " (%s)\n", strerror(errno));                   \
+	} while (false)
+
+#define TAG "incfs_perf"
+
+struct options {
+	int blocks; /* -b number of diff block sizes */
+	bool no_cleanup; /* -c don't clean up after */
+	const char *test_dir; /* -d working directory */
+	const char *file_types; /* -f sScCvV */
+	bool no_native; /* -n don't test native files */
+	bool no_random; /* -r don't do random reads*/
+	bool no_linear; /* -R random reads only */
+	size_t size; /* -s file size as power of 2 */
+	int tries; /* -t times to run test*/
+};
+
+enum flags {
+	SHUFFLE = 1,
+	COMPRESS = 2,
+	VERIFY = 4,
+	LAST_FLAG = 8,
+};
+
+void print_help(void)
+{
+	puts(
+	"incfs_perf. Performance test tool for incfs\n"
+	"\tTests read performance of incfs by creating files of various types\n"
+	"\tflushing caches and then reading them back.\n"
+	"\tEach file is read with different block sizes and average\n"
+	"\tthroughput in megabytes/second and memory usage are reported for\n"
+	"\teach block size\n"
+	"\tNative files are tested for comparison\n"
+	"\tNative files are created in native folder, incfs files are created\n"
+	"\tin src folder which is mounted on dst folder\n"
+	"\n"
+	"\t-bn (default 8) number of different block sizes, starting at 4096\n"
+	"\t                and doubling\n"
+	"\t-c		   don't Clean up - leave files and mount point\n"
+	"\t-d dir          create directories in dir\n"
+	"\t-fs|Sc|Cv|V     restrict which files are created.\n"
+	"\t                s blocks not shuffled, S blocks shuffled\n"
+	"\t                c blocks not compress, C blocks compressed\n"
+	"\t                v files not verified, V files verified\n"
+	"\t                If a letter is omitted, both options are tested\n"
+	"\t                If no letter are given, incfs is not tested\n"
+	"\t-n              Don't test native files\n"
+	"\t-r              No random reads (sequential only)\n"
+	"\t-R              Random reads only (no sequential)\n"
+	"\t-sn (default 30)File size as power of 2\n"
+	"\t-tn (default 5) Number of tries per file. Results are averaged\n"
+	);
+}
+
+int parse_options(int argc, char *const *argv, struct options *options)
+{
+	signed char c;
+
+	/* Set defaults here */
+	*options = (struct options){
+		.blocks = 8,
+		.test_dir = ".",
+		.tries = 5,
+		.size = 30,
+	};
+
+	/* Load options from command line here */
+	while ((c = getopt(argc, argv, "b:cd:f::hnrRs:t:")) != -1) {
+		switch (c) {
+		case 'b':
+			options->blocks = strtol(optarg, NULL, 10);
+			break;
+
+		case 'c':
+			options->no_cleanup = true;
+			break;
+
+		case 'd':
+			options->test_dir = optarg;
+			break;
+
+		case 'f':
+			if (optarg)
+				options->file_types = optarg;
+			else
+				options->file_types = "sS";
+			break;
+
+		case 'h':
+			print_help();
+			exit(0);
+
+		case 'n':
+			options->no_native = true;
+			break;
+
+		case 'r':
+			options->no_random = true;
+			break;
+
+		case 'R':
+			options->no_linear = true;
+			break;
+
+		case 's':
+			options->size = strtol(optarg, NULL, 10);
+			break;
+
+		case 't':
+			options->tries = strtol(optarg, NULL, 10);
+			break;
+
+		default:
+			print_help();
+			return -EINVAL;
+		}
+	}
+
+	options->size = 1L << options->size;
+
+	return 0;
+}
+
+void shuffle(size_t *buffer, size_t size)
+{
+	size_t i;
+
+	for (i = 0; i < size; ++i) {
+		size_t j = random() * (size - i - 1) / RAND_MAX;
+		size_t temp = buffer[i];
+
+		buffer[i] = buffer[j];
+		buffer[j] = temp;
+	}
+}
+
+int get_free_memory(void)
+{
+	FILE *meminfo = fopen("/proc/meminfo", "re");
+	char field[256];
+	char value[256] = {};
+
+	if (!meminfo)
+		return -ENOENT;
+
+	while (fscanf(meminfo, "%[^:]: %s kB\n", field, value) == 2) {
+		if (!strcmp(field, "MemFree"))
+			break;
+		*value = 0;
+	}
+
+	fclose(meminfo);
+
+	if (!*value)
+		return -ENOENT;
+
+	return strtol(value, NULL, 10);
+}
+
+int write_data(int cmd_fd, int dir_fd, const char *name, size_t size, int flags)
+{
+	int fd = openat(dir_fd, name, O_RDWR | O_CLOEXEC);
+	struct incfs_permit_fill permit_fill = {
+		.file_descriptor = fd,
+	};
+	int block_count = 1 + (size - 1) / INCFS_DATA_FILE_BLOCK_SIZE;
+	size_t *blocks = malloc(sizeof(size_t) * block_count);
+	int error = 0;
+	size_t i;
+	uint8_t data[INCFS_DATA_FILE_BLOCK_SIZE] = {};
+	uint8_t compressed_data[INCFS_DATA_FILE_BLOCK_SIZE] = {};
+	struct incfs_fill_block fill_block = {
+		.compression = COMPRESSION_NONE,
+		.data_len = sizeof(data),
+		.data = ptr_to_u64(data),
+	};
+
+	if (!blocks) {
+		err_msg("Out of memory");
+		error = -errno;
+		goto out;
+	}
+
+	if (fd == -1) {
+		err_msg("Could not open file for writing %s", name);
+		error = -errno;
+		goto out;
+	}
+
+	if (ioctl(cmd_fd, INCFS_IOC_PERMIT_FILL, &permit_fill)) {
+		err_msg("Failed to call PERMIT_FILL");
+		error = -errno;
+		goto out;
+	}
+
+	for (i = 0; i < block_count; ++i)
+		blocks[i] = i;
+
+	if (flags & SHUFFLE)
+		shuffle(blocks, block_count);
+
+	if (flags & COMPRESS) {
+		size_t comp_size = LZ4_compress_default(
+			(char *)data, (char *)compressed_data, sizeof(data),
+			ARRAY_SIZE(compressed_data));
+
+		if (comp_size <= 0) {
+			error = -EBADMSG;
+			goto out;
+		}
+		fill_block.compression = COMPRESSION_LZ4;
+		fill_block.data = ptr_to_u64(compressed_data);
+		fill_block.data_len = comp_size;
+	}
+
+	for (i = 0; i < block_count; ++i) {
+		struct incfs_fill_blocks fill_blocks = {
+			.count = 1,
+			.fill_blocks = ptr_to_u64(&fill_block),
+		};
+
+		fill_block.block_index = blocks[i];
+		int written = ioctl(fd, INCFS_IOC_FILL_BLOCKS, &fill_blocks);
+
+		if (written != 1) {
+			error = -errno;
+			err_msg("Failed to write block %lu in file %s", i,
+				name);
+			break;
+		}
+	}
+
+out:
+	free(blocks);
+	close(fd);
+	sync();
+	return error;
+}
+
+int measure_read_throughput_internal(const char *tag, int dir, const char *name,
+				     const struct options *options, bool random)
+{
+	int block;
+
+	if (random)
+		printf("%32s(random)", tag);
+	else
+		printf("%40s", tag);
+
+	for (block = 0; block < options->blocks; ++block) {
+		size_t buffer_size;
+		char *buffer;
+		int try;
+		double time = 0;
+		double throughput;
+		int memory = 0;
+
+		buffer_size = 1 << (block + 12);
+		buffer = malloc(buffer_size);
+
+		for (try = 0; try < options->tries; ++try) {
+			int err;
+			struct timespec start_time, end_time;
+			off_t i;
+			int fd;
+			size_t offsets_size = options->size / buffer_size;
+			size_t *offsets =
+				malloc(offsets_size * sizeof(*offsets));
+			int start_memory, end_memory;
+
+			if (!offsets) {
+				err_msg("Not enough memory");
+				return -ENOMEM;
+			}
+
+			for (i = 0; i < offsets_size; ++i)
+				offsets[i] = i * buffer_size;
+
+			if (random)
+				shuffle(offsets, offsets_size);
+
+			err = drop_caches();
+			if (err) {
+				err_msg("Failed to drop caches");
+				return err;
+			}
+
+			start_memory = get_free_memory();
+			if (start_memory < 0) {
+				err_msg("Failed to get start memory");
+				return start_memory;
+			}
+
+			fd = openat(dir, name, O_RDONLY | O_CLOEXEC);
+			if (fd == -1) {
+				err_msg("Failed to open file");
+				return err;
+			}
+
+			err = clock_gettime(CLOCK_MONOTONIC, &start_time);
+			if (err) {
+				err_msg("Failed to get start time");
+				return err;
+			}
+
+			for (i = 0; i < offsets_size; ++i)
+				if (pread(fd, buffer, buffer_size,
+					  offsets[i]) != buffer_size) {
+					err_msg("Failed to read file");
+					err = -errno;
+					goto fail;
+				}
+
+			err = clock_gettime(CLOCK_MONOTONIC, &end_time);
+			if (err) {
+				err_msg("Failed to get start time");
+				goto fail;
+			}
+
+			end_memory = get_free_memory();
+			if (end_memory < 0) {
+				err_msg("Failed to get end memory");
+				return end_memory;
+			}
+
+			time += end_time.tv_sec - start_time.tv_sec;
+			time += (end_time.tv_nsec - start_time.tv_nsec) / 1e9;
+
+			close(fd);
+			fd = -1;
+			memory += start_memory - end_memory;
+
+fail:
+			free(offsets);
+			close(fd);
+			if (err)
+				return err;
+		}
+
+		throughput = options->size * options->tries / time;
+		printf("%10.3e %10d", throughput, memory / options->tries);
+		free(buffer);
+	}
+
+	printf("\n");
+	return 0;
+}
+
+int measure_read_throughput(const char *tag, int dir, const char *name,
+			    const struct options *options)
+{
+	int err = 0;
+
+	if (!options->no_linear)
+		err = measure_read_throughput_internal(tag, dir, name, options,
+						       false);
+
+	if (!err && !options->no_random)
+		err = measure_read_throughput_internal(tag, dir, name, options,
+						       true);
+	return err;
+}
+
+int test_native_file(int dir, const struct options *options)
+{
+	const char *name = "file";
+	int fd;
+	char buffer[4096] = {};
+	off_t i;
+	int err;
+
+	fd = openat(dir, name, O_CREAT | O_WRONLY | O_CLOEXEC, 0600);
+	if (fd == -1) {
+		err_msg("Could not open native file");
+		return -errno;
+	}
+
+	for (i = 0; i < options->size; i += sizeof(buffer))
+		if (pwrite(fd, buffer, sizeof(buffer), i) != sizeof(buffer)) {
+			err_msg("Failed to write file");
+			err = -errno;
+			goto fail;
+		}
+
+	close(fd);
+	sync();
+	fd = -1;
+
+	err = measure_read_throughput("native", dir, name, options);
+
+fail:
+	close(fd);
+	return err;
+}
+
+struct hash_block {
+	char data[INCFS_DATA_FILE_BLOCK_SIZE];
+};
+
+static struct hash_block *build_mtree(size_t size, char *root_hash,
+				      int *mtree_block_count)
+{
+	char data[INCFS_DATA_FILE_BLOCK_SIZE] = {};
+	const int digest_size = SHA256_DIGEST_SIZE;
+	const int hash_per_block = INCFS_DATA_FILE_BLOCK_SIZE / digest_size;
+	int block_count = 0;
+	int hash_block_count = 0;
+	int total_tree_block_count = 0;
+	int tree_lvl_index[INCFS_MAX_MTREE_LEVELS] = {};
+	int tree_lvl_count[INCFS_MAX_MTREE_LEVELS] = {};
+	int levels_count = 0;
+	int i, level;
+	struct hash_block *mtree;
+
+	if (size == 0)
+		return 0;
+
+	block_count = 1 + (size - 1) / INCFS_DATA_FILE_BLOCK_SIZE;
+	hash_block_count = block_count;
+	for (i = 0; hash_block_count > 1; i++) {
+		hash_block_count = (hash_block_count + hash_per_block - 1) /
+				   hash_per_block;
+		tree_lvl_count[i] = hash_block_count;
+		total_tree_block_count += hash_block_count;
+	}
+	levels_count = i;
+
+	for (i = 0; i < levels_count; i++) {
+		int prev_lvl_base = (i == 0) ? total_tree_block_count :
+					       tree_lvl_index[i - 1];
+
+		tree_lvl_index[i] = prev_lvl_base - tree_lvl_count[i];
+	}
+
+	*mtree_block_count = total_tree_block_count;
+	mtree = calloc(total_tree_block_count, sizeof(*mtree));
+	/* Build level 0 hashes. */
+	for (i = 0; i < block_count; i++) {
+		int block_index = tree_lvl_index[0] + i / hash_per_block;
+		int block_off = (i % hash_per_block) * digest_size;
+		char *hash_ptr = mtree[block_index].data + block_off;
+
+		sha256(data, INCFS_DATA_FILE_BLOCK_SIZE, hash_ptr);
+	}
+
+	/* Build higher levels of hash tree. */
+	for (level = 1; level < levels_count; level++) {
+		int prev_lvl_base = tree_lvl_index[level - 1];
+		int prev_lvl_count = tree_lvl_count[level - 1];
+
+		for (i = 0; i < prev_lvl_count; i++) {
+			int block_index =
+				i / hash_per_block + tree_lvl_index[level];
+			int block_off = (i % hash_per_block) * digest_size;
+			char *hash_ptr = mtree[block_index].data + block_off;
+
+			sha256(mtree[i + prev_lvl_base].data,
+			       INCFS_DATA_FILE_BLOCK_SIZE, hash_ptr);
+		}
+	}
+
+	/* Calculate root hash from the top block */
+	sha256(mtree[0].data, INCFS_DATA_FILE_BLOCK_SIZE, root_hash);
+
+	return mtree;
+}
+
+static int load_hash_tree(int cmd_fd, int dir, const char *name,
+			  struct hash_block *mtree, int mtree_block_count)
+{
+	int err;
+	int i;
+	int fd;
+	struct incfs_fill_block *fill_block_array =
+		calloc(mtree_block_count, sizeof(struct incfs_fill_block));
+	struct incfs_fill_blocks fill_blocks = {
+		.count = mtree_block_count,
+		.fill_blocks = ptr_to_u64(fill_block_array),
+	};
+	struct incfs_permit_fill permit_fill;
+
+	if (!fill_block_array)
+		return -ENOMEM;
+
+	for (i = 0; i < fill_blocks.count; i++) {
+		fill_block_array[i] = (struct incfs_fill_block){
+			.block_index = i,
+			.data_len = INCFS_DATA_FILE_BLOCK_SIZE,
+			.data = ptr_to_u64(mtree[i].data),
+			.flags = INCFS_BLOCK_FLAGS_HASH
+		};
+	}
+
+	fd = openat(dir, name, O_RDONLY | O_CLOEXEC);
+	if (fd < 0) {
+		err = errno;
+		goto failure;
+	}
+
+	permit_fill.file_descriptor = fd;
+	if (ioctl(cmd_fd, INCFS_IOC_PERMIT_FILL, &permit_fill)) {
+		err_msg("Failed to call PERMIT_FILL");
+		err = -errno;
+		goto failure;
+	}
+
+	err = ioctl(fd, INCFS_IOC_FILL_BLOCKS, &fill_blocks);
+	close(fd);
+	if (err < fill_blocks.count)
+		err = errno;
+	else
+		err = 0;
+
+failure:
+	free(fill_block_array);
+	return err;
+}
+
+int test_incfs_file(int dst_dir, const struct options *options, int flags)
+{
+	int cmd_file = openat(dst_dir, INCFS_PENDING_READS_FILENAME,
+			      O_RDONLY | O_CLOEXEC);
+	int err;
+	char name[4];
+	incfs_uuid_t id;
+	char tag[256];
+
+	snprintf(name, sizeof(name), "%c%c%c",
+		 flags & SHUFFLE ? 'S' : 's',
+		 flags & COMPRESS ? 'C' : 'c',
+		 flags & VERIFY ? 'V' : 'v');
+
+	if (cmd_file == -1) {
+		err_msg("Could not open command file");
+		return -errno;
+	}
+
+	if (flags & VERIFY) {
+		char root_hash[INCFS_MAX_HASH_SIZE];
+		int mtree_block_count;
+		struct hash_block *mtree = build_mtree(options->size, root_hash,
+						       &mtree_block_count);
+
+		if (!mtree) {
+			err_msg("Failed to build hash tree");
+			err = -ENOMEM;
+			goto fail;
+		}
+
+		err = crypto_emit_file(cmd_file, NULL, name, &id, options->size,
+				       root_hash, "add_data");
+
+		if (!err)
+			err = load_hash_tree(cmd_file, dst_dir, name, mtree,
+					     mtree_block_count);
+
+		free(mtree);
+	} else
+		err = emit_file(cmd_file, NULL, name, &id, options->size, NULL);
+
+	if (err) {
+		err_msg("Failed to create file %s", name);
+		goto fail;
+	}
+
+	if (write_data(cmd_file, dst_dir, name, options->size, flags))
+		goto fail;
+
+	snprintf(tag, sizeof(tag), "incfs%s%s%s",
+		 flags & SHUFFLE ? "(shuffle)" : "",
+		 flags & COMPRESS ? "(compress)" : "",
+		 flags & VERIFY ? "(verify)" : "");
+
+	err = measure_read_throughput(tag, dst_dir, name, options);
+
+fail:
+	close(cmd_file);
+	return err;
+}
+
+bool skip(struct options const *options, int flag, char c)
+{
+	if (!options->file_types)
+		return false;
+
+	if (flag && strchr(options->file_types, tolower(c)))
+		return true;
+
+	if (!flag && strchr(options->file_types, toupper(c)))
+		return true;
+
+	return false;
+}
+
+int main(int argc, char *const *argv)
+{
+	struct options options;
+	int err;
+	const char *native_dir = "native";
+	const char *src_dir = "src";
+	const char *dst_dir = "dst";
+	int native_dir_fd = -1;
+	int src_dir_fd = -1;
+	int dst_dir_fd = -1;
+	int block;
+	int flags;
+
+	err = parse_options(argc, argv, &options);
+	if (err)
+		return err;
+
+	err = chdir(options.test_dir);
+	if (err) {
+		err_msg("Failed to change to %s", options.test_dir);
+		return -errno;
+	}
+
+	/* Clean up any interrupted previous runs */
+	while (!umount(dst_dir))
+		;
+
+	err = remove_dir(native_dir) || remove_dir(src_dir) ||
+	      remove_dir(dst_dir);
+	if (err)
+		return err;
+
+	err = mkdir(native_dir, 0700);
+	if (err) {
+		err_msg("Failed to make directory %s", src_dir);
+		err = -errno;
+		goto cleanup;
+	}
+
+	err = mkdir(src_dir, 0700);
+	if (err) {
+		err_msg("Failed to make directory %s", src_dir);
+		err = -errno;
+		goto cleanup;
+	}
+
+	err = mkdir(dst_dir, 0700);
+	if (err) {
+		err_msg("Failed to make directory %s", src_dir);
+		err = -errno;
+		goto cleanup;
+	}
+
+	err = mount_fs_opt(dst_dir, src_dir, "readahead=0,rlog_pages=0", 0);
+	if (err) {
+		err_msg("Failed to mount incfs");
+		goto cleanup;
+	}
+
+	native_dir_fd = open(native_dir, O_RDONLY | O_CLOEXEC);
+	src_dir_fd = open(src_dir, O_RDONLY | O_CLOEXEC);
+	dst_dir_fd = open(dst_dir, O_RDONLY | O_CLOEXEC);
+	if (native_dir_fd == -1 || src_dir_fd == -1 || dst_dir_fd == -1) {
+		err_msg("Failed to open native, src or dst dir");
+		err = -errno;
+		goto cleanup;
+	}
+
+	printf("%40s", "");
+	for (block = 0; block < options.blocks; ++block)
+		printf("%21d", 1 << (block + 12));
+	printf("\n");
+
+	if (!err && !options.no_native)
+		err = test_native_file(native_dir_fd, &options);
+
+	for (flags = 0; flags < LAST_FLAG && !err; ++flags) {
+		if (skip(&options, flags & SHUFFLE, 's') ||
+		    skip(&options, flags & COMPRESS, 'c') ||
+		    skip(&options, flags & VERIFY, 'v'))
+			continue;
+		err = test_incfs_file(dst_dir_fd, &options, flags);
+	}
+
+cleanup:
+	close(native_dir_fd);
+	close(src_dir_fd);
+	close(dst_dir_fd);
+	if (!options.no_cleanup) {
+		umount(dst_dir);
+		remove_dir(native_dir);
+		remove_dir(dst_dir);
+		remove_dir(src_dir);
+	}
+
+	return err;
+}
diff --git a/tools/testing/selftests/filesystems/incfs/incfs_stress.c b/tools/testing/selftests/filesystems/incfs/incfs_stress.c
index 4238803cccd0..a1d491755832 100644
--- a/tools/testing/selftests/filesystems/incfs/incfs_stress.c
+++ b/tools/testing/selftests/filesystems/incfs/incfs_stress.c
@@ -48,7 +48,7 @@ int cancel_threads;
 
 int parse_options(int argc, char *const *argv, struct options *options)
 {
-	char c;
+	signed char c;
 
 	/* Set defaults here */
 	*options = (struct options){
@@ -70,23 +70,23 @@ int parse_options(int argc, char *const *argv, struct options *options)
 			break;
 
 		case 'g':
-			options->rng_seed = atoi(optarg);
+			options->rng_seed = strtol(optarg, NULL, 10);
 			break;
 
 		case 'n':
-			options->num_reads = atoi(optarg);
+			options->num_reads = strtol(optarg, NULL, 10);
 			break;
 
 		case 'r':
-			options->readers = atoi(optarg);
+			options->readers = strtol(optarg, NULL, 10);
 			break;
 
 		case 's':
-			options->size = atoi(optarg);
+			options->size = strtol(optarg, NULL, 10);
 			break;
 
 		case 't':
-			options->timeout = atoi(optarg);
+			options->timeout = strtol(optarg, NULL, 10);
 			break;
 		}
 	}
@@ -94,33 +94,6 @@ int parse_options(int argc, char *const *argv, struct options *options)
 	return 0;
 }
 
-unsigned int rnd(unsigned int max, unsigned int *seed)
-{
-	return rand_r(seed) * ((uint64_t)max + 1) / RAND_MAX;
-}
-
-int remove_dir(const char *dir)
-{
-	int err = rmdir(dir);
-
-	if (err && errno == ENOTEMPTY) {
-		err = delete_dir_tree(dir);
-		if (err) {
-			err_msg("Can't delete dir %s", dir);
-			return err;
-		}
-
-		return 0;
-	}
-
-	if (err && errno != ENOENT) {
-		err_msg("Can't delete dir %s", dir);
-		return -errno;
-	}
-
-	return 0;
-}
-
 void *reader(void *data)
 {
 	struct read_data *read_data = (struct read_data *)data;
diff --git a/tools/testing/selftests/filesystems/incfs/incfs_test.c b/tools/testing/selftests/filesystems/incfs/incfs_test.c
index 6809399eac97..203c30a62493 100644
--- a/tools/testing/selftests/filesystems/incfs/incfs_test.c
+++ b/tools/testing/selftests/filesystems/incfs/incfs_test.c
@@ -29,7 +29,6 @@
 
 #define TEST_FAILURE 1
 #define TEST_SUCCESS 0
-#define INCFS_MAX_MTREE_LEVELS 8
 
 #define INCFS_ROOT_INODE 0
 
@@ -2624,7 +2623,7 @@ static int large_file(char *mount_dir)
 		.fill_blocks = ptr_to_u64(block_buf),
 	};
 	incfs_uuid_t id;
-	int fd;
+	int fd = -1;
 
 	backing_dir = create_backing_dir(mount_dir);
 	if (!backing_dir)
diff --git a/tools/testing/selftests/filesystems/incfs/utils.c b/tools/testing/selftests/filesystems/incfs/utils.c
index e194f63ba922..a80123294d5a 100644
--- a/tools/testing/selftests/filesystems/incfs/utils.c
+++ b/tools/testing/selftests/filesystems/incfs/utils.c
@@ -25,6 +25,45 @@
 #define __S_IFREG S_IFREG
 #endif
 
+unsigned int rnd(unsigned int max, unsigned int *seed)
+{
+	return rand_r(seed) * ((uint64_t)max + 1) / RAND_MAX;
+}
+
+int remove_dir(const char *dir)
+{
+	int err = rmdir(dir);
+
+	if (err && errno == ENOTEMPTY) {
+		err = delete_dir_tree(dir);
+		if (err)
+			return err;
+		return 0;
+	}
+
+	if (err && errno != ENOENT)
+		return -errno;
+
+	return 0;
+}
+
+int drop_caches(void)
+{
+	int drop_caches =
+		open("/proc/sys/vm/drop_caches", O_WRONLY | O_CLOEXEC);
+	int i;
+
+	if (drop_caches == -1)
+		return -errno;
+	i = write(drop_caches, "3", 1);
+	close(drop_caches);
+
+	if (i != 1)
+		return -errno;
+
+	return 0;
+}
+
 int mount_fs(const char *mount_dir, const char *backing_dir,
 	     int read_timeout_ms)
 {
diff --git a/tools/testing/selftests/filesystems/incfs/utils.h b/tools/testing/selftests/filesystems/incfs/utils.h
index 9af63e4e922c..5b59272dbb7f 100644
--- a/tools/testing/selftests/filesystems/incfs/utils.h
+++ b/tools/testing/selftests/filesystems/incfs/utils.h
@@ -18,6 +18,13 @@
 #endif
 
 #define SHA256_DIGEST_SIZE 32
+#define INCFS_MAX_MTREE_LEVELS 8
+
+unsigned int rnd(unsigned int max, unsigned int *seed);
+
+int remove_dir(const char *dir);
+
+int drop_caches(void);
 
 int mount_fs(const char *mount_dir, const char *backing_dir,
 	     int read_timeout_ms);