[Buildroot] [PATCH] package/dosfstools: introduce sanitation step during install

[Markus Mayer <mmayer@broadcom.com>]

We can't install dosfstools into the target directory directly, because
it'll install *all* binaries, even the disabled ones.

Also, we can't just delete dosfstools binaries from the target
directory after installing them, because some tools of the same name
may be provided by other packages (specifically Busybox). When a tool
is disabled in dosfstools, it only means that dosfstools shouldn't
install its own copy, not that it is okay to remove a tool that might
already be there.

To avoid any issues, we install dosfstools into a temporary location,
remove the binaries that have been disabled in the Buildroot
configuration, and only then copy the rest to the target location.

We also extend sanitation to include man pages, so only man pages for
enabled tools are copied to the target.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
---

We discovered the issue at hand because we are using Busybox for most
of our tools, including FAT related tools. When we needed to add
fsck.fat to our root file system, we had to enable DOSFSTOOLS, because
Busybox doesn't provide it. And suddenly all our FAT related tools
(except fsck.fat) had disappeared from the rootfs! That was not at all
the idea.

The reason, as it turned out, was DOSFSTOOLS doing it sanitation
directly inside the target directory, which indiscriminately removed
binaries, even if they were enabled via a different package (BUSYBOX in
our case).

Hence the approach using a temporary install location.

 package/dosfstools/dosfstools.mk | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/package/dosfstools/dosfstools.mk b/package/dosfstools/dosfstools.mk
index 6eb0851d0e23..30a35e3f9b8f 100644
--- a/package/dosfstools/dosfstools.mk
+++ b/package/dosfstools/dosfstools.mk
@@ -10,6 +10,7 @@ DOSFSTOOLS_SITE = https://github.com/dosfstools/dosfstools/releases/download/v$(
 DOSFSTOOLS_LICENSE = GPL-3.0+
 DOSFSTOOLS_LICENSE_FILES = COPYING
 DOSFSTOOLS_CONF_OPTS = --enable-compat-symlinks --exec-prefix=/
+DOSFSTOOLS_TEMP=$(BASE_DIR)/build/dosfstools-install
 HOST_DOSFSTOOLS_CONF_OPTS = --enable-compat-symlinks
 
 ifeq ($(BR2_PACKAGE_HAS_UDEV),y)
@@ -24,26 +25,48 @@ DOSFSTOOLS_CONF_OPTS += LIBS="-liconv"
 DOSFSTOOLS_DEPENDENCIES += libiconv
 endif
 
+# Install into temporary location
+DOSFSTOOLS_INSTALL_TARGET_OPTS = \
+	DESTDIR=$(DOSFSTOOLS_TEMP) \
+	install
+
+# Clean out our temporary install location before installation
+define DOSFSTOOLS_CLEAR_TEMP
+	rm -rf $(DOSFSTOOLS_TEMP)
+endef
+DOSFSTOOLS_PRE_INSTALL_TARGET_HOOKS += DOSFSTOOLS_CLEAR_TEMP
+
+# Sanitize temporary install location after installation
 ifeq ($(BR2_PACKAGE_DOSFSTOOLS_FATLABEL),)
 define DOSFSTOOLS_REMOVE_FATLABEL
-	rm -f $(addprefix $(TARGET_DIR)/sbin/,dosfslabel fatlabel)
+	rm -f $(addprefix $(DOSFSTOOLS_TEMP)/sbin/,dosfslabel fatlabel)
+	rm -f $(addprefix $(DOSFSTOOLS_TEMP)/usr/share/man/man8/,dosfslabel.8 fatlabel.8)
 endef
 DOSFSTOOLS_POST_INSTALL_TARGET_HOOKS += DOSFSTOOLS_REMOVE_FATLABEL
 endif
 
 ifeq ($(BR2_PACKAGE_DOSFSTOOLS_FSCK_FAT),)
 define DOSFSTOOLS_REMOVE_FSCK_FAT
-	rm -f $(addprefix $(TARGET_DIR)/sbin/,fsck.fat dosfsck fsck.msdos fsck.vfat)
+	rm -f $(addprefix $(DOSFSTOOLS_TEMP)/sbin/,fsck.fat dosfsck fsck.msdos fsck.vfat)
+	rm -f $(addprefix $(DOSFSTOOLS_TEMP)/usr/share/man/man8/,fsck.fat.8 dosfsck.8 fsck.msdos.8 fsck.vfat.8)
 endef
 DOSFSTOOLS_POST_INSTALL_TARGET_HOOKS += DOSFSTOOLS_REMOVE_FSCK_FAT
 endif
 
 ifeq ($(BR2_PACKAGE_DOSFSTOOLS_MKFS_FAT),)
 define DOSFSTOOLS_REMOVE_MKFS_FAT
-	rm -f $(addprefix $(TARGET_DIR)/sbin/,mkfs.fat mkdosfs mkfs.msdos mkfs.vfat)
+	rm -f $(addprefix $(DOSFSTOOLS_TEMP)/sbin/,mkfs.fat mkdosfs mkfs.msdos mkfs.vfat)
+	rm -f $(addprefix $(DOSFSTOOLS_TEMP)/usr/share/man/man8/,mkfs.fat.8 mkdosfs.8 mkfs.msdos.8 mkfs.vfat.8)
 endef
 DOSFSTOOLS_POST_INSTALL_TARGET_HOOKS += DOSFSTOOLS_REMOVE_MKFS_FAT
 endif
 
+# Install what's left into the actual target directory
+define DOSFSTOOLS_TARGET_INSTALL
+	tar -C $(DOSFSTOOLS_TEMP) -c -f - . | tar -C $(TARGET_DIR) -x -f -
+	rm -rf $(DOSFSTOOLS_TEMP)
+endef
+DOSFSTOOLS_POST_INSTALL_TARGET_HOOKS += DOSFSTOOLS_TARGET_INSTALL
+
 $(eval $(autotools-package))
 $(eval $(host-autotools-package))
-- 
2.17.1