[PATCH 1/3] [RFC] fstests: btrfs: add functions to set and reset required number of SCRATCH_DEV_POOL

[PATCH 1/3] [RFC] fstests: btrfs: add functions to set and reset required number of SCRATCH_DEV_POOL

[Anand Jain]

This patch provides functions
 _scratch_dev_pool_get()
 _scratch_dev_pool_put()

Which will help to set/reset SCRATCH_DEV_POOL with the required
number of devices. SCRATCH_DEV_POOL_SAVED will hold all the devices.

Usage:
  _scratch_dev_pool_get() <ndevs>
  :: do stuff

  _scratch_dev_pool_put()

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 common/rc | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/common/rc b/common/rc
index 91e8f1c8e693..33632fd8e4a3 100644
--- a/common/rc
+++ b/common/rc
@@ -786,6 +786,53 @@ _scratch_mkfs()
     esac
 }
 
+#
+# $1 Number of the scratch devs required
+#
+_scratch_dev_pool_get()
+{
+	if [ $# != 1 ]; then
+		_fail "Usage: _scratch_dev_pool_get ndevs"
+	fi
+
+	local test_ndevs=$1
+	local config_ndevs=`echo $SCRATCH_DEV_POOL| wc -w`
+	local devs[]="( $SCRATCH_DEV_POOL )"
+
+	typeset -p config_ndevs >/dev/null 2>&1
+	if [ $? != 0 ]; then
+		_fail "Bug: unset val, must call _scratch_dev_pool_get before _scratch_dev_pool_put"
+	fi
+
+	# _require_scratch_dev_pool $test_ndevs
+	# must have already checked the min required devices
+	# but just in case, trap here for any potential bugs
+	# perpetuating any further
+	if [ $config_ndevs -lt $test_ndevs ]; then
+		_notrun "Need at least test requested number of ndevs $test_ndevs"
+	fi
+
+	SCRATCH_DEV_POOL_SAVED=${SCRATCH_DEV_POOL}
+	export SCRATCH_DEV_POOL_SAVED
+	SCRATCH_DEV_POOL=${devs[@]:0:$test_ndevs}
+	export SCRATCH_DEV_POOL
+}
+
+_scratch_dev_pool_put()
+{
+	typeset -p SCRATCH_DEV_POOL_SAVED >/dev/null 2>&1
+	if [ $? != 0 ]; then
+		_fail "Bug: unset val, must call _scratch_dev_pool_get before _scratch_dev_pool_put"
+	fi
+
+	if [ -z "$SCRATCH_DEV_POOL_SAVED" ]; then
+		_fail "Bug: str empty, must call _scratch_dev_pool_get before _scratch_dev_pool_put"
+	fi
+
+	export SCRATCH_DEV_POOL=$SCRATCH_DEV_POOL_SAVED
+	export SCRATCH_DEV_POOL_SAVED=""
+}
+
 _scratch_pool_mkfs()
 {
     case $FSTYP in
-- 
2.7.0

[PATCH 2/3] [RFC] fstests: btrfs: add functions to get and put a device for replace target

[Anand Jain]

For the replace tests we need a device as a spare device,
here functions _spare_dev_get() and _spare_dev_put()
will get it from the SCRATCH_DEV_POOL_SAVED, which is set
when _scratch_dev_pool_get() is called, and is based on how
many has already been assigned to SCRATCH_DEV_POOL.

 usage:
   _scratch_dev_pool_get 3
   _spare_dev_get

      SPARE_DEV will have a device set which can be
      used as the replace target device.

   _spare_dev_put
   _scratch_dev_pool_put

_spare_dev_get() will pick the next device after SCRATCH_DEV_POOL
devices, from the SCRATCH_DEV_POOL_SAVED, and assigns it to
SPARE_DEV. _spare_dev_put() will set to SPARE_DEV to null.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 common/rc | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/common/rc b/common/rc
index 33632fd8e4a3..f2b39ddbee0c 100644
--- a/common/rc
+++ b/common/rc
@@ -786,6 +786,51 @@ _scratch_mkfs()
     esac
 }
 
+_spare_dev_get()
+{
+	typeset -p SCRATCH_DEV_POOL_SAVED >/dev/null 2>&1
+	if [ $? != 0 ]; then
+		_fail "Bug: unset val, must call _scratch_dev_pool_get before _spare_dev_get"
+	fi
+
+	if [ -z "$SCRATCH_DEV_POOL_SAVED" ]; then
+		_fail "Bug: str empty, must call _scratch_dev_pool_get before _spare_dev_get"
+	fi
+
+	# Check if the spare is already assigned
+	typeset -p SPARE_DEV >/dev/null 2>&1
+	if [ $? == 0 ]; then
+		if [ ! -z "$SPARE_DEV" ]; then
+			_fail "Bug: SPARE_DEV = $SPARE_DEV already assigned"
+		fi
+	fi
+
+	local ndevs=`echo $SCRATCH_DEV_POOL| wc -w`
+	local config_ndevs=`echo $SCRATCH_DEV_POOL_SAVED| wc -w`
+
+	if [ $ndevs -eq $config_ndevs ]; then
+		_notrun "All devs used no spare"
+	fi
+	# Get a dev that is not used
+	local devs[]="( $SCRATCH_DEV_POOL_SAVED )"
+	SPARE_DEV=${devs[@]:$ndevs:1}
+	export SPARE_DEV
+}
+
+_spare_dev_put()
+{
+	typeset -p SPARE_DEV >/dev/null 2>&1
+	if [ $? != 0 ]; then
+		_fail "Bug: unset val, must call _spare_dev_get before its put"
+	fi
+
+	if [ -z "$SPARE_DEV" ]; then
+		_fail "Bug: str empty, must call _spare_dev_get before its put"
+	fi
+
+	export SPARE_DEV=""
+}
+
 #
 # $1 Number of the scratch devs required
 #
-- 
2.7.0

[PATCH 3/3] fstests: btrfs: 027 make use of new device get and put helper functions

[Anand Jain]

Below patches added helper function to get the requested
number of devices for scratch and spare device

fstest: btrfs: add functions to get and put a device for replace target
fstests: btrfs: add functions to set and reset required number of SCRATCH_DEV_POOL

This patch makes use of them.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 tests/btrfs/027 | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/tests/btrfs/027 b/tests/btrfs/027
index f0844a14f8e6..905dc0ebaa27 100755
--- a/tests/btrfs/027
+++ b/tests/btrfs/027
@@ -57,17 +57,22 @@ _require_command "$WIPEFS_PROG" wipefs
 run_test()
 {
 	local mkfs_opts=$1
-	local saved_scratch_dev_pool=$SCRATCH_DEV_POOL
-	local replace_dev=`echo $SCRATCH_DEV_POOL | awk '{print $NF}'`
+	local ndevs=`echo $SCRATCH_DEV_POOL | wc -w`
+
+	# reserve one for replace target
+	((ndevs--))
+
+	_scratch_dev_pool_get $ndevs
+	_spare_dev_get
 
 	echo "Test $mkfs_opts" >>$seqres.full
 
-	SCRATCH_DEV_POOL=`echo $SCRATCH_DEV_POOL | sed -e "s# *$replace_dev *##"`
 	_scratch_pool_mkfs $mkfs_opts >>$seqres.full 2>&1
 	# make sure we created btrfs with desired options
 	if [ $? -ne 0 ]; then
 		echo "mkfs $mkfs_opts failed"
-		SCRATCH_DEV_POOL=$saved_scratch_dev_pool
+		_spare_dev_put
+		_scratch_dev_pool_put
 		return
 	fi
 	_scratch_mount >>$seqres.full 2>&1
@@ -89,17 +94,19 @@ run_test()
 	_scratch_mount -o degraded >>$seqres.full 2>&1
 
 	# replace $missing_dev with $replace_dev and scrub it to double-check
-	$BTRFS_UTIL_PROG replace start -B -r $missing_dev_id $replace_dev \
+	$BTRFS_UTIL_PROG replace start -B -r $missing_dev_id $SPARE_DEV \
 		$SCRATCH_MNT -f >>$seqres.full 2>&1
 	if [ $? -ne 0 ]; then
 		echo "btrfs replace failed"
-		SCRATCH_DEV_POOL=$saved_scratch_dev_pool
+		_spare_dev_put
+		_scratch_dev_pool_put
 		return
 	fi
 	$BTRFS_UTIL_PROG scrub start -B $SCRATCH_MNT >>$seqres.full 2>&1
 	if [ $? -ne 0 ]; then
 		echo "btrfs scrub failed"
-		SCRATCH_DEV_POOL=$saved_scratch_dev_pool
+		_spare_dev_put
+		_scratch_dev_pool_put
 		return
 	fi
 
@@ -107,7 +114,8 @@ run_test()
 	# we called _require_scratch_nocheck instead of _require_scratch
 	# do check after test for each profile config
 	_check_scratch_fs
-	SCRATCH_DEV_POOL=$saved_scratch_dev_pool
+	_spare_dev_put
+	_scratch_dev_pool_put
 }
 
 echo "Silence is golden"
-- 
2.7.0