Add btrfs command check (for future btrfs-progs switch from Depends to Recommends in .deb)

lib/bkctld-inc

@@ -15,10 +15,9 @@ create_inc_btrfs() {
     inc_path=$(inc_path "${jail_name}" "${inc_name}")
 
     btrfs_bin=$(command -v btrfs)
-    ### Pseudo-code
-    # if [ -z "${btrfs_bin}" ]; then
-    #     error "Can't find btrfs"
-    # fi
+    if [ -z "${btrfs_bin}" ]; then
+        error "btrfs not found. Please install brtfs-progs."
+    fi
 
     if dry_run; then
         echo "[dry-run] btrfs subvolume snapshot of ${jail_path} to ${inc_path}"

lib/bkctld-inc-lock

@@ -12,8 +12,12 @@ target_path="${2:?}"
 
 lock_target() {
     target="${1:?}"
+    btrfs_bin=$(command -v btrfs)
+    if [ -z ${btrfs_bin} ]; then
+        error "btrfs not found. Please install brtfs-progs."
+    fi
     if is_btrfs "${target}"; then
-        btrfs property set -ts "${target}" ro true
+        ${btrfs_bin} property set -ts "${target}" ro true
         info "Lock ${target}: done".
     else
         info "Lock ${target}: not BTRFS, nothing done".
@@ -21,8 +25,12 @@ lock_target() {
 }
 unlock_target() {
     target="${1:?}"
+    btrfs_bin=$(command -v btrfs)
+    if [ -z ${btrfs_bin} ]; then
+        error "btrfs not found. Please install brtfs-progs."
+    fi
     if is_btrfs "${target}"; then
-        btrfs property set -ts "${target}" ro false
+        ${btrfs_bin} property set -ts "${target}" ro false
         info "Unlock ${target}: done."
     else
         info "Unlock ${target}: not BTRFS, nothing done."

lib/bkctld-init

@@ -18,9 +18,13 @@ test -d "${jail_path}" && error "Skip jail \`${jail_name}' : it already exists"
 # Create config and jails directory
 mkdir --parents "${CONFDIR}" "${JAILDIR}"
 
+btrfs_bin=$(command -v btrfs)
+if [ -z ${btrfs_bin} ]; then
+    error "btrfs not found. Please install brtfs-progs."
+fi
 
 if is_btrfs "$(dirname "${JAILDIR}")" || is_btrfs "${JAILDIR}"; then
-    /bin/btrfs subvolume create "${jail_path}"
+    ${btrfs_bin} subvolume create "${jail_path}"
 else
     mkdir --parents "${jail_path}"
 fi

lib/bkctld-remove

@@ -52,9 +52,13 @@ fi
 rm -f "${CONFDIR}/${jail_name}"
 rm -rf "$(jail_config_dir "${jail_name}")"
 
-jail_inode=$(stat --format=%i "${jail_path}")
-if [ "${jail_inode}" -eq 256 ]; then
-    /bin/btrfs subvolume delete "${jail_path}" | debug
+btrfs_bin=$(command -v btrfs)
+if [ -z ${btrfs_bin} ]; then
+    error "btrfs not found. Please install brtfs-progs."
+fi
+
+if is_btrfs "${jail_path}"; then
+    ${btrfs_bin} subvolume delete "${jail_path}" | debug
 else
     rm -rf "${jail_path:?}" | debug
 fi
@@ -65,7 +69,7 @@ if [ -d "${incs_path}" ]; then
     for inc in ${incs}; do
         inc_inode=$(stat --format=%i "${incs_path}/${inc}")
         if [ "${inc_inode}" -eq 256 ]; then
-            /bin/btrfs subvolume delete "${incs_path}/${inc}" | debug
+            ${btrfs_bin} subvolume delete "${incs_path}/${inc}" | debug
         else
             warning "You need to purge \`${incs_path}/${inc}' manually"
         fi

lib/bkctld-rm

@@ -61,11 +61,16 @@ delete_inc_btrfs() {
     inc_name=$2
 
     inc_path=$(inc_path "${jail_name}" "${inc_name}")
+    btrfs_bin=$(command -v btrfs)
+
+    if [ -z ${btrfs_bin} ]; then
+        error "btrfs not found. Please install brtfs-progs."
+    fi
 
     if dry_run; then
         echo "[dry-run] delete btrfs subvolume ${inc_path}"
     else
-        /bin/btrfs subvolume delete "${inc_path}" | debug
+        ${btrfs_bin} subvolume delete "${inc_path}" | debug
     fi
 }
 delete_inc_ext4() {