[Buildroot] [PATCH v2 3/6] fs/ext2: use mkfs to generate rootfs image

[Samuel Martin <s.martin49@gmail.com>]

From: S?bastien Szymanski <sebastien.szymanski@armadeus.com>

mkfs is now capable of generating rootfs images. Use mkfs intead of
genext2fs. As we let mkfs calculate the block size and the number of
inodes needed we can drop BR2_TARGET_ROOTFS_EXT2_INODES and
BR2_TARGET_ROOTFS_EXT2_EXTRA_INODES and rename
BR2_TARGET_ROOTFS_EXT2_BLOCKS to BR2_TARGET_ROOTFS_EXT2_SIZE

Signed-off-by: S?bastien Szymanski <sebastien.szymanski@armadeus.com>
Signed-off-by: Samuel Martin <s.martin49@gmail.com>

---
changes v1->v2:
- rebase
- add default size value
---
 Config.in.legacy  | 34 ++++++++++++++++++++++++++++++++++
 fs/ext2/Config.in | 27 +++++++++------------------
 fs/ext2/ext2.mk   | 22 +++++++++++-----------
 3 files changed, 54 insertions(+), 29 deletions(-)

diff --git a/Config.in.legacy b/Config.in.legacy
index 453c5eb8b8..c086d30ee5 100644
--- a/Config.in.legacy
+++ b/Config.in.legacy
@@ -145,6 +145,40 @@ endif
 ###############################################################################
 comment "Legacy options removed in 2017.08"
 
+config BR2_TARGET_ROOTFS_EXT2_INODES
+	int "exact number of inodes has been removed"
+	default 0
+	help
+	  Buildroot uses mkfs.ext2/3/4 to generate ext2/3/4 images. So let mkfs
+	  automatically selects the number of inodes needed. Set this option to
+	  0.
+
+config BR2_TARGET_ROOTFS_EXT2_INODES_WRAP
+	bool
+	default y if BR2_TARGET_ROOTFS_EXT2_INODES != 0
+	select BR2_LEGACY
+
+config BR2_TARGET_ROOTFS_EXT2_EXTRA_INODES
+	int "extra inodes has been removed" if BR2_TARGET_ROOTFS_EXT2_INODES = 0
+	default 0
+	help
+	  Buildroot uses mkfs.ext2/3/4 to generate ext2/3/4 images. So let mkfs
+	  automatically selects the number of inodes needed. Set this option to
+	  0.
+
+config BR2_TARGET_ROOTFS_EXT2_EXTRA_INODES_WRAP
+	bool
+	default y if BR2_TARGET_ROOTFS_EXT2_EXTRA_INODES != 0
+	select BR2_LEGACY
+
+config BR2_TARGET_ROOTFS_EXT2_BLOCKS
+	int "exact size in blocks has been removed"
+	default 0
+	help
+	  This option has been removed in favor of BR2_TARGET_ROOTFS_EXT2_SIZE.
+
+# Note: BR2_TARGET_ROOTFS_EXT2_BLOCKS still reference in fs/ext2/Config.in
+
 config BR2_STRIP_none
 	bool "Strip command 'none' has been removed"
 	select BR2_LEGACY
diff --git a/fs/ext2/Config.in b/fs/ext2/Config.in
index 33891601f4..d3e9d16a44 100644
--- a/fs/ext2/Config.in
+++ b/fs/ext2/Config.in
@@ -1,6 +1,6 @@
 config BR2_TARGET_ROOTFS_EXT2
 	bool "ext2/3/4 root filesystem"
-	select BR2_PACKAGE_HOST_MKE2IMG
+	select BR2_PACKAGE_HOST_E2FSPROGS
 	help
 	  Build an ext2/3/4 root filesystem
 
@@ -44,24 +44,15 @@ config BR2_TARGET_ROOTFS_EXT2_REV
 config BR2_TARGET_ROOTFS_EXT2_LABEL
 	string "filesystem label"
 
-# 61440 = 60MB, i.e usually small enough to fit on a 64MB media
-config BR2_TARGET_ROOTFS_EXT2_BLOCKS
-	int "exact size in blocks"
-	default 61440
+config BR2_TARGET_ROOTFS_EXT2_SIZE
+	string "exact size"
+	default BR2_TARGET_ROOTFS_EXT2_BLOCKS if BR2_TARGET_ROOTFS_EXT2_BLOCKS != 0 # legacy 2017.08
+	default "60M" # default size
 	help
-	  Specify the file system size as a number of 1024-byte blocks.
-
-config BR2_TARGET_ROOTFS_EXT2_INODES
-	int "exact number of inodes (leave at 0 for auto calculation)"
-	default 0
-
-config BR2_TARGET_ROOTFS_EXT2_EXTRA_INODES
-	int "extra inodes" if BR2_TARGET_ROOTFS_EXT2_INODES = 0
-	default 0
-	help
-	  Enter here the number of extra free inodes you want on
-	  your filesystem. By default, Buildroot will not leave
-	  many free inodes.
+	  The size of the filesystem image. If it does not have a suffix, it is
+	  interpreted as power-of-two kilobytes. If it is suffixed by 'k', 'm',
+	  'g', 't' (either upper-case or lower-case), then it is interpreted in
+	  power-of-two kilobytes, megabytes, gigabytes, terabytes, etc.
 
 config BR2_TARGET_ROOTFS_EXT2_RESBLKS
 	int "reserved blocks percentage"
diff --git a/fs/ext2/ext2.mk b/fs/ext2/ext2.mk
index ce567de34c..5269e99a29 100644
--- a/fs/ext2/ext2.mk
+++ b/fs/ext2/ext2.mk
@@ -4,28 +4,28 @@
 #
 ################################################################################
 
-EXT2_OPTS = -G $(BR2_TARGET_ROOTFS_EXT2_GEN) -R $(BR2_TARGET_ROOTFS_EXT2_REV)
-
-EXT2_OPTS += -b $(BR2_TARGET_ROOTFS_EXT2_BLOCKS)
-
-ifneq ($(strip $(BR2_TARGET_ROOTFS_EXT2_INODES)),0)
-EXT2_OPTS += -i $(BR2_TARGET_ROOTFS_EXT2_INODES)
+EXT2_SIZE = $(call qstrip,$(BR2_TARGET_ROOTFS_EXT2_SIZE))
+ifeq ($(EXT2_SIZE),)
+$(error BR2_TARGET_ROOTFS_EXT2_SIZE cannot be empty)
 endif
-EXT2_OPTS += -I $(BR2_TARGET_ROOTFS_EXT2_EXTRA_INODES)
 
-EXT2_OPTS += -r $(BR2_TARGET_ROOTFS_EXT2_RESBLKS)
+EXT2_OPTS = -d $(TARGET_DIR)
+EXT2_OPTS += -r $(BR2_TARGET_ROOTFS_EXT2_REV)
+
+EXT2_OPTS += -m $(BR2_TARGET_ROOTFS_EXT2_RESBLKS)
 
 # qstrip results in stripping consecutive spaces into a single one. So the
 # variable is not qstrip-ed to preserve the integrity of the string value.
 EXT2_LABEL := $(subst ",,$(BR2_TARGET_ROOTFS_EXT2_LABEL))
 #" Syntax highlighting... :-/ )
 
-EXT2_OPTS += -l "$(EXT2_LABEL)"
+EXT2_OPTS += -L "$(EXT2_LABEL)"
 
-ROOTFS_EXT2_DEPENDENCIES = host-mke2img
+ROOTFS_EXT2_DEPENDENCIES = host-e2fsprogs
 
 define ROOTFS_EXT2_CMD
-	PATH=$(BR_PATH) mke2img -d $(TARGET_DIR) $(EXT2_OPTS) -o $@
+	rm -f $@
+	PATH=$(BR_PATH) mkfs.ext$(BR2_TARGET_ROOTFS_EXT2_GEN) $(EXT2_OPTS) $@ $(EXT2_SIZE)
 endef
 
 rootfs-ext2-symlink:
-- 
2.13.2