[PATCH v5] zram-swap: explicitly use mkswap/swapon/swapoff from /sbin

[Rui Salvaterra]

The required BusyBox applets are enabled by default, so we can rely on them
being present in the system. This way, we make sure there are no conflicts with
less featured variants of these same applets which might also be present in the
system.

Fixes: 0bd7dfa3ed60 ("zram-swap: enable swap discard")

v5: addressed Adrian Schmutzler's comments

Signed-off-by: Rui Salvaterra <rsalvaterra at gmail.com>
---
 package/system/zram-swap/Makefile        |  4 ++--
 package/system/zram-swap/files/zram.init | 18 +++++++++---------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/package/system/zram-swap/Makefile b/package/system/zram-swap/Makefile
index 5c132c9062..9a18dd3417 100644
--- a/package/system/zram-swap/Makefile
+++ b/package/system/zram-swap/Makefile
@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=zram-swap
-PKG_RELEASE:=6
+PKG_RELEASE:=7
 
 PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)
 
@@ -17,7 +17,7 @@ include $(INCLUDE_DIR)/package.mk
 define Package/zram-swap
   SECTION:=utils
   CATEGORY:=Base system
-  DEPENDS:=+kmod-zram +!(BUSYBOX_CONFIG_MKSWAP&&BUSYBOX_CONFIG_SWAPON&&BUSYBOX_CONFIG_SWAPOFF):swap-utils
+  DEPENDS:=+kmod-zram + at BUSYBOX_CONFIG_MKSWAP + at BUSYBOX_CONFIG_SWAPON + at BUSYBOX_CONFIG_FEATURE_SWAPON_DISCARD + at BUSYBOX_CONFIG_FEATURE_SWAPON_PRI + at BUSYBOX_CONFIG_SWAPOFF
   TITLE:=ZRAM swap scripts
   PKGARCH:=all
 endef
diff --git a/package/system/zram-swap/files/zram.init b/package/system/zram-swap/files/zram.init
index 42c084855a..f31a87438c 100755
--- a/package/system/zram-swap/files/zram.init
+++ b/package/system/zram-swap/files/zram.init
@@ -35,18 +35,18 @@ zram_applicable()
 		return 1
 	}
 
-	command -v mkswap >/dev/null || {
-		logger -s -t zram_applicable -p daemon.err "[ERROR] 'mkswap' not installed"
+	[ -x /sbin/mkswap ] || {
+		logger -s -t zram_applicable -p daemon.err "[ERROR] 'BusyBox mkswap' not installed"
 		return 1
 	}
 
-	command -v swapon >/dev/null || {
-		logger -s -t zram_applicable -p daemon.err "[ERROR] 'swapon' not installed"
+	[ -x /sbin/swapon ] || {
+		logger -s -t zram_applicable -p daemon.err "[ERROR] 'BusyBox swapon' not installed"
 		return 1
 	}
 
-	command -v swapoff >/dev/null || {
-		logger -s -t zram_applicable -p daemon.err "[ERROR] 'swapoff' not installed"
+	[ -x /sbin/swapoff ] || {
+		logger -s -t zram_applicable -p daemon.err "[ERROR] 'BusyBox swapoff' not installed"
 		return 1
 	}
 }
@@ -181,8 +181,8 @@ start()
 	zram_comp_algo "$zram_dev"
 	zram_comp_streams "$zram_dev"
 	echo $(( $zram_size * 1024 * 1024 )) >"/sys/block/$( basename "$zram_dev" )/disksize"
-	mkswap "$zram_dev"
-	swapon -d $zram_priority "$zram_dev"
+	/sbin/mkswap "$zram_dev"
+	/sbin/swapon -d $zram_priority "$zram_dev"
 }
 
 stop()
@@ -191,7 +191,7 @@ stop()
 
 	for zram_dev in $( grep zram /proc/swaps |awk '{print $1}' ); do {
 		logger -s -t zram_stop -p daemon.debug "deactivate swap $zram_dev"
-		swapoff "$zram_dev" && zram_reset "$zram_dev" "claiming memory back"
+		/sbin/swapoff "$zram_dev" && zram_reset "$zram_dev" "claiming memory back"
 		local dev_index="$( echo $zram_dev | grep -o "[0-9]*$" )"
 		if [ $dev_index -ne 0 ]; then
 			logger -s -t zram_stop -p daemon.debug "removing zram $zram_dev"
-- 
2.28.0