diff --git a/Makefile b/Makefile
index a1cc457b..377093d3 100644
--- a/Makefile
+++ b/Makefile
@@ -173,7 +173,8 @@ libbtrfs_objects = common/send-stream.o common/send-utils.o kernel-lib/rbtree.o
 		   common/device-scan.o common/path-utils.o \
 		   common/utils.o libbtrfsutil/subvolume.o libbtrfsutil/stubs.o \
 		   crypto/hash.o crypto/xxhash.o $(CRYPTO_OBJECTS) \
-		   common/open-utils.o common/units.o common/device-utils.o
+		   common/open-utils.o common/units.o common/device-utils.o \
+		   common/parse-utils.o
 libbtrfs_headers = common/send-stream.h common/send-utils.h send.h kernel-lib/rbtree.h btrfs-list.h \
 	       crypto/crc32c.h kernel-lib/list.h kerncompat.h \
 	       kernel-lib/radix-tree.h kernel-lib/sizes.h kernel-lib/raid56.h \
diff --git a/cmds/filesystem.c b/cmds/filesystem.c
index db8433ba..4ca155a4 100644
--- a/cmds/filesystem.c
+++ b/cmds/filesystem.c
@@ -46,6 +46,7 @@
 #include "common/device-scan.h"
 #include "common/device-utils.h"
 #include "common/open-utils.h"
+#include "common/parse-utils.h"
 
 /*
  * for btrfs fi show, we maintain a hash of fsids we've already printed.
diff --git a/cmds/qgroup.c b/cmds/qgroup.c
index 7dc1d5d9..ab4bf5b9 100644
--- a/cmds/qgroup.c
+++ b/cmds/qgroup.c
@@ -30,6 +30,7 @@
 #include "common/utils.h"
 #include "common/help.h"
 #include "common/units.h"
+#include "common/parse-utils.h"
 
 static const char * const qgroup_cmd_group_usage[] = {
 	"btrfs qgroup <command> [options] <path>",
diff --git a/common/parse-utils.c b/common/parse-utils.c
new file mode 100644
index 00000000..12e13b48
--- /dev/null
+++ b/common/parse-utils.c
@@ -0,0 +1,127 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "kerncompat.h"
+#include <limits.h>
+#include <ctype.h>
+#include "common/parse-utils.h"
+#include "common/messages.h"
+
+u64 parse_size_from_string(const char *s)
+{
+	char c;
+	char *endptr;
+	u64 mult = 1;
+	u64 ret;
+
+	if (!s) {
+		error("size value is empty");
+		exit(1);
+	}
+	if (s[0] == '-') {
+		error("size value '%s' is less equal than 0", s);
+		exit(1);
+	}
+	ret = strtoull(s, &endptr, 10);
+	if (endptr == s) {
+		error("size value '%s' is invalid", s);
+		exit(1);
+	}
+	if (endptr[0] && endptr[1]) {
+		error("illegal suffix contains character '%c' in wrong position",
+			endptr[1]);
+		exit(1);
+	}
+	/*
+	 * strtoll returns LLONG_MAX when overflow, if this happens,
+	 * need to call strtoull to get the real size
+	 */
+	if (errno == ERANGE && ret == ULLONG_MAX) {
+		error("size value '%s' is too large for u64", s);
+		exit(1);
+	}
+	if (endptr[0]) {
+		c = tolower(endptr[0]);
+		switch (c) {
+		case 'e':
+			mult *= 1024;
+			/* fallthrough */
+		case 'p':
+			mult *= 1024;
+			/* fallthrough */
+		case 't':
+			mult *= 1024;
+			/* fallthrough */
+		case 'g':
+			mult *= 1024;
+			/* fallthrough */
+		case 'm':
+			mult *= 1024;
+			/* fallthrough */
+		case 'k':
+			mult *= 1024;
+			/* fallthrough */
+		case 'b':
+			break;
+		default:
+			error("unknown size descriptor '%c'", c);
+			exit(1);
+		}
+	}
+	/* Check whether ret * mult overflow */
+	if (fls64(ret) + fls64(mult) - 1 > 64) {
+		error("size value '%s' is too large for u64", s);
+		exit(1);
+	}
+	ret *= mult;
+	return ret;
+}
+
+enum btrfs_csum_type parse_csum_type(const char *s)
+{
+	if (strcasecmp(s, "crc32c") == 0) {
+		return BTRFS_CSUM_TYPE_CRC32;
+	} else if (strcasecmp(s, "xxhash64") == 0 ||
+		   strcasecmp(s, "xxhash") == 0) {
+		return BTRFS_CSUM_TYPE_XXHASH;
+	} else if (strcasecmp(s, "sha256") == 0) {
+		return BTRFS_CSUM_TYPE_SHA256;
+	} else if (strcasecmp(s, "blake2b") == 0 ||
+		   strcasecmp(s, "blake2") == 0) {
+		return BTRFS_CSUM_TYPE_BLAKE2;
+	} else {
+		error("unknown csum type %s", s);
+		exit(1);
+	}
+	/* not reached */
+	return 0;
+}
+
+/*
+ * Find last set bit in a 64-bit word. Returns 0 if value is 0 or the position
+ * of the last set bit if value is nonzero. The last (most significant) bit is
+ * at position 64.
+ */
+int fls64(u64 x)
+{
+	int i;
+
+	for (i = 0; i < 64; i++)
+		if (x << i & (1ULL << 63))
+			return 64 - i;
+	return 64 - i;
+}
+
diff --git a/common/parse-utils.h b/common/parse-utils.h
new file mode 100644
index 00000000..8133d64e
--- /dev/null
+++ b/common/parse-utils.h
@@ -0,0 +1,28 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __PARSE_UTILS_H__
+#define __PARSE_UTILS_H__
+
+#include "kerncompat.h"
+#include "kernel-shared/ctree.h"
+
+u64 parse_size_from_string(const char *s);
+enum btrfs_csum_type parse_csum_type(const char *s);
+
+int fls64(u64 x);
+
+#endif
diff --git a/common/utils.c b/common/utils.c
index 418001af..8bcc00ff 100644
--- a/common/utils.c
+++ b/common/utils.c
@@ -227,90 +227,6 @@ int set_label(const char *btrfs_dev, const char *label)
 	return ret;
 }
 
-/*
- * A not-so-good version fls64. No fascinating optimization since
- * no one except parse_size_from_string uses it
- */
-static int fls64(u64 x)
-{
-	int i;
-
-	for (i = 0; i <64; i++)
-		if (x << i & (1ULL << 63))
-			return 64 - i;
-	return 64 - i;
-}
-
-u64 parse_size_from_string(const char *s)
-{
-	char c;
-	char *endptr;
-	u64 mult = 1;
-	u64 ret;
-
-	if (!s) {
-		error("size value is empty");
-		exit(1);
-	}
-	if (s[0] == '-') {
-		error("size value '%s' is less equal than 0", s);
-		exit(1);
-	}
-	ret = strtoull(s, &endptr, 10);
-	if (endptr == s) {
-		error("size value '%s' is invalid", s);
-		exit(1);
-	}
-	if (endptr[0] && endptr[1]) {
-		error("illegal suffix contains character '%c' in wrong position",
-			endptr[1]);
-		exit(1);
-	}
-	/*
-	 * strtoll returns LLONG_MAX when overflow, if this happens,
-	 * need to call strtoull to get the real size
-	 */
-	if (errno == ERANGE && ret == ULLONG_MAX) {
-		error("size value '%s' is too large for u64", s);
-		exit(1);
-	}
-	if (endptr[0]) {
-		c = tolower(endptr[0]);
-		switch (c) {
-		case 'e':
-			mult *= 1024;
-			/* fallthrough */
-		case 'p':
-			mult *= 1024;
-			/* fallthrough */
-		case 't':
-			mult *= 1024;
-			/* fallthrough */
-		case 'g':
-			mult *= 1024;
-			/* fallthrough */
-		case 'm':
-			mult *= 1024;
-			/* fallthrough */
-		case 'k':
-			mult *= 1024;
-			/* fallthrough */
-		case 'b':
-			break;
-		default:
-			error("unknown size descriptor '%c'", c);
-			exit(1);
-		}
-	}
-	/* Check whether ret * mult overflow */
-	if (fls64(ret) + fls64(mult) - 1 > 64) {
-		error("size value '%s' is too large for u64", s);
-		exit(1);
-	}
-	ret *= mult;
-	return ret;
-}
-
 u64 parse_qgroupid(const char *p)
 {
 	char *s = strchr(p, '/');
@@ -365,26 +281,6 @@ err:
 	exit(-1);
 }
 
-enum btrfs_csum_type parse_csum_type(const char *s)
-{
-	if (strcasecmp(s, "crc32c") == 0) {
-		return BTRFS_CSUM_TYPE_CRC32;
-	} else if (strcasecmp(s, "xxhash64") == 0 ||
-		   strcasecmp(s, "xxhash") == 0) {
-		return BTRFS_CSUM_TYPE_XXHASH;
-	} else if (strcasecmp(s, "sha256") == 0) {
-		return BTRFS_CSUM_TYPE_SHA256;
-	} else if (strcasecmp(s, "blake2b") == 0 ||
-		   strcasecmp(s, "blake2") == 0) {
-		return BTRFS_CSUM_TYPE_BLAKE2;
-	} else {
-		error("unknown csum type %s", s);
-		exit(1);
-	}
-	/* not reached */
-	return 0;
-}
-
 void btrfs_format_csum(u16 csum_type, const u8 *data, char *output)
 {
 	int i;
diff --git a/common/utils.h b/common/utils.h
index 45a4cea3..2369be94 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -42,12 +42,9 @@ enum exclusive_operation {
 	BTRFS_EXCLOP_UNKNOWN = -1,
 };
 
-enum btrfs_csum_type parse_csum_type(const char *s);
-
 /* 2 for "0x", 2 for each byte, plus nul */
 #define BTRFS_CSUM_STRING_LEN		(2 + 2 * BTRFS_CSUM_SIZE + 1)
 void btrfs_format_csum(u16 csum_type, const u8 *data, char *output);
-u64 parse_size_from_string(const char *s);
 u64 parse_qgroupid(const char *p);
 u64 arg_strtou64(const char *str);
 int get_fs_info(const char *path, struct btrfs_ioctl_fs_info_args *fi_args,
diff --git a/convert/main.c b/convert/main.c
index 815a8636..68f85988 100644
--- a/convert/main.c
+++ b/convert/main.c
@@ -100,6 +100,7 @@
 #include "common/task-utils.h"
 #include "common/path-utils.h"
 #include "common/help.h"
+#include "common/parse-utils.h"
 #include "mkfs/common.h"
 #include "convert/common.h"
 #include "convert/source-fs.h"
diff --git a/mkfs/main.c b/mkfs/main.c
index 1a9c3f7e..c544c133 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -44,6 +44,7 @@
 #include "kernel-lib/list_sort.h"
 #include "common/help.h"
 #include "common/rbtree-utils.h"
+#include "common/parse-utils.h"
 #include "mkfs/common.h"
 #include "mkfs/rootdir.h"
 #include "common/fsfeatures.h"