common/btrfs: lookup running processes using pgrep

Certain helper functions and the testcase btrfs/132 use the following
script to find running processes:

	while ps aux | grep "balance start" | grep -qv grep; do
	<>
	done

Instead, using pgrep is more efficient.

	while pgrep -f "btrfs balance start" > /dev/null; do
	<>
	done

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>

2 files changed, 6 insertions, 6 deletions

diff --git a/common/btrfs b/common/btrfs
index 2c086227d8..a320b0e41d 100644
--- a/common/btrfs
+++ b/common/btrfs
@@ -327,7 +327,7 @@ _btrfs_kill_stress_balance_pid()
 	kill $balance_pid &> /dev/null
 	wait $balance_pid &> /dev/null
 	# Wait for the balance operation to finish.
-	while ps aux | grep "balance start" | grep -qv grep; do
+	while pgrep -f "btrfs balance start" > /dev/null; do
 		sleep 1
 	done
 }
@@ -381,7 +381,7 @@ _btrfs_kill_stress_scrub_pid()
        kill $scrub_pid &> /dev/null
        wait $scrub_pid &> /dev/null
        # Wait for the scrub operation to finish.
-       while ps aux | grep "scrub start" | grep -qv grep; do
+       while pgrep -f "btrfs scrub start" > /dev/null; do
                sleep 1
        done
 }
@@ -415,7 +415,7 @@ _btrfs_kill_stress_defrag_pid()
        kill $defrag_pid &> /dev/null
        wait $defrag_pid &> /dev/null
        # Wait for the defrag operation to finish.
-       while ps aux | grep "btrfs filesystem defrag" | grep -qv grep; do
+       while pgrep -f "btrfs filesystem defrag" > /dev/null; do
                sleep 1
        done
 }
@@ -444,7 +444,7 @@ _btrfs_kill_stress_remount_compress_pid()
 	kill $remount_pid &> /dev/null
 	wait $remount_pid &> /dev/null
 	# Wait for the remount loop to finish.
-	while ps aux | grep "mount.*${btrfs_mnt}" | grep -qv grep; do
+	while pgrep -f "mount.*${btrfs_mnt}" > /dev/null; do
 		sleep 1
 	done
 }
@@ -507,7 +507,7 @@ _btrfs_kill_stress_replace_pid()
        kill $replace_pid &> /dev/null
        wait $replace_pid &> /dev/null
        # Wait for the replace operation to finish.
-       while ps aux | grep "replace start" | grep -qv grep; do
+       while pgrep -f "btrfs replace start" > /dev/null; do
                sleep 1
        done
 }
diff --git a/tests/btrfs/132 b/tests/btrfs/132
index f50420f511..b48395c188 100755
--- a/tests/btrfs/132
+++ b/tests/btrfs/132
@@ -70,7 +70,7 @@ kill $pids
 wait
 
 # Wait all writers really exits
-while ps aux | grep "$SCRATCH_MNT" | grep -qv grep; do
+while pgrep -f "$SCRATCH_MNT" > /dev/null; do
 	sleep 1
 done