[PATCH 1/2] common/rc: Enable _format_swapfile to return the swap size

[Carlos Maiolino <cmaiolino@redhat.com>]

Once the kernel is free to not map the full swap file during a swapon call,
it can be useful to know the exact size of the swap area created during
_format_swapfile().

To achieve this, it is required to change _require_scratch_swapfile(), to drop
the _format_swapfile() return value, otherwise, it will also have a return value
that will end up in tests outputs causing tests to fail.

Tests using _format_swapfile() that do not require the swap file size do not
need to be modified, as the return value will be simply ignored.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 common/rc | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/common/rc b/common/rc
index 7f693d39..fb1f32e0 100644
--- a/common/rc
+++ b/common/rc
@@ -2587,6 +2587,7 @@ _require_odirect()
 _format_swapfile() {
 	local fname="$1"
 	local sz="$2"
+	local swap_log=""
 
 	rm -f "$fname"
 	touch "$fname"
@@ -2595,8 +2596,11 @@ _format_swapfile() {
 	$CHATTR_PROG +C "$fname" > /dev/null 2>&1
 	_pwrite_byte 0x61 0 "$sz" "$fname" >> $seqres.full
 	# Ignore permission complaints on filesystems that don't support perms
-	$MKSWAP_PROG "$fname" 2>&1 >> $seqres.full | \
-		grep -v "insecure permission"
+	swap_log=$($MKSWAP_PROG "$fname" 2>&1 | grep -v "insecure permission")
+	echo $swap_log >> $seqres.full
+
+	# return created swap size
+	echo $swap_log | grep -oP '(?<=size = )\w+'
 }
 
 _swapon_file() {
@@ -2628,7 +2632,7 @@ _require_scratch_swapfile()
 	_scratch_mount
 
 	# Minimum size for mkswap is 10 pages
-	_format_swapfile "$SCRATCH_MNT/swap" $(($(get_page_size) * 10))
+	_format_swapfile "$SCRATCH_MNT/swap" $(($(get_page_size) * 10)) > /dev/null
 
 	# ext* has supported all variants of swap files since their
 	# introduction, so swapon should not fail.
-- 
2.31.1