Make dbufstat work on FreeBSD

With procfs_list kstats implemented for FreeBSD, dbufs are now exposed
as kstat.zfs.misc.dbufs.

On FreeBSD, dbufstats can use the sysctl instead of procfs when no
input file has been given.

Enable the dbufstats tests on FreeBSD.

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Ryan Moeller <[email protected]>
Closes #11008

7 files changed, 56 insertions, 16 deletions

diff --git a/cmd/dbufstat/dbufstat.in b/cmd/dbufstat/dbufstat.in
index 98eb79057..1d4eb39d7 100755
--- a/cmd/dbufstat/dbufstat.in
+++ b/cmd/dbufstat/dbufstat.in
@@ -113,6 +113,21 @@ cmd = ("Usage: dbufstat [-bdhnrtvx] [-i file] [-f fields] [-o file] "
 raw = 0
 
 
+if sys.platform.startswith("freebsd"):
+    import io
+    # Requires py-sysctl on FreeBSD
+    import sysctl
+
+    def default_ifile():
+        dbufs = sysctl.filter("kstat.zfs.misc.dbufs")[0].value
+        sys.stdin = io.StringIO(dbufs)
+        return "-"
+
+elif sys.platform.startswith("linux"):
+    def default_ifile():
+        return "/proc/spl/kstat/zfs/dbufs"
+
+
 def print_incompat_helper(incompat):
     cnt = 0
     for key in sorted(incompat):
@@ -645,7 +660,7 @@ def main():
             sys.exit(1)
 
     if not ifile:
-        ifile = '/proc/spl/kstat/zfs/dbufs'
+        ifile = default_ifile()
 
     if ifile is not "-":
         try:
diff --git a/module/os/freebsd/spl/spl_kstat.c b/module/os/freebsd/spl/spl_kstat.c
index 4cc77e20a..b26753bac 100644
--- a/module/os/freebsd/spl/spl_kstat.c
+++ b/module/os/freebsd/spl/spl_kstat.c
@@ -231,6 +231,7 @@ restart:
 	}
 	free(ksp->ks_raw_buf, M_TEMP);
 	mutex_exit(ksp->ks_lock);
+	sbuf_trim(sb);
 	rc = sbuf_finish(sb);
 	if (rc == 0)
 		rc = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb));
diff --git a/tests/runfiles/common.run b/tests/runfiles/common.run
index a29578b36..228bd5eac 100644
--- a/tests/runfiles/common.run
+++ b/tests/runfiles/common.run
@@ -30,6 +30,11 @@ tests = ['alloc_class_001_pos', 'alloc_class_002_neg', 'alloc_class_003_pos',
     'alloc_class_013_pos']
 tags = ['functional', 'alloc_class']
 
+[tests/functional/arc]
+tests = ['dbufstats_001_pos', 'dbufstats_002_pos', 'dbufstats_003_pos',
+    'arcstats_runtime_tuning']
+tags = ['functional', 'arc']
+
 [tests/functional/atime]
 tests = ['atime_001_pos', 'atime_002_neg', 'root_atime_off', 'root_atime_on']
 tags = ['functional', 'atime']
diff --git a/tests/runfiles/linux.run b/tests/runfiles/linux.run
index b6508a5cb..94964434e 100644
--- a/tests/runfiles/linux.run
+++ b/tests/runfiles/linux.run
@@ -26,11 +26,6 @@ tags = ['functional']
 tests = ['posix_001_pos', 'posix_002_pos', 'posix_003_pos']
 tags = ['functional', 'acl', 'posix']
 
-[tests/functional/arc:Linux]
-tests = ['dbufstats_001_pos', 'dbufstats_002_pos', 'dbufstats_003_pos',
-    'arcstats_runtime_tuning']
-tags = ['functional', 'arc']
-
 [tests/functional/atime:Linux]
 tests = ['atime_003_pos', 'root_relatime_on']
 tags = ['functional', 'atime']
diff --git a/tests/zfs-tests/include/libtest.shlib b/tests/zfs-tests/include/libtest.shlib
index 9898bada9..98ef54e4d 100644
--- a/tests/zfs-tests/include/libtest.shlib
+++ b/tests/zfs-tests/include/libtest.shlib
@@ -4154,18 +4154,36 @@ function ls_xattr # path
 	esac
 }
 
+function kstat # stat flags?
+{
+	typeset stat=$1
+	typeset flags=${2-"-n"}
+
+	case $(uname) in
+	FreeBSD)
+		sysctl $flags kstat.zfs.misc.$stat
+		;;
+	Linux)
+		typeset zfs_kstat="/proc/spl/kstat/zfs/$stat"
+		[[ -f "$zfs_kstat" ]] || return 1
+		cat $zfs_kstat
+		;;
+	*)
+		false
+		;;
+	esac
+}
+
 function get_arcstat # stat
 {
 	typeset stat=$1
 
 	case $(uname) in
 	FreeBSD)
-		sysctl -n kstat.zfs.misc.arcstats.$stat
+		kstat arcstats.$stat
 		;;
 	Linux)
-		typeset zfs_arcstats="/proc/spl/kstat/zfs/arcstats"
-		[[ -f "$zfs_arcstats" ]] || return 1
-		grep $stat $zfs_arcstats | awk '{print $3}'
+		kstat arcstats | awk "/$stat/ { print \$3 }"
 		;;
 	*)
 		false
diff --git a/tests/zfs-tests/tests/functional/arc/dbufstats_001_pos.ksh b/tests/zfs-tests/tests/functional/arc/dbufstats_001_pos.ksh
index 4884f11bb..0577a6b80 100755
--- a/tests/zfs-tests/tests/functional/arc/dbufstats_001_pos.ksh
+++ b/tests/zfs-tests/tests/functional/arc/dbufstats_001_pos.ksh
@@ -55,7 +55,13 @@ function testdbufstat # stat_name dbufstat_filter
 
         [[ -n "$2" ]] && filter="-F $2"
 
-	from_dbufstat=$(grep -w "$name" "$DBUFSTATS_FILE" | awk '{ print $3 }')
+	if is_linux; then
+		from_dbufstat=$(grep -w "$name" "$DBUFSTATS_FILE" |
+		    awk '{ print $3 }')
+	else
+		from_dbufstat=$(awk "/dbufstats\.$name:/ { print \$2 }" \
+		    "$DBUFSTATS_FILE")
+	fi
 	from_dbufs=$(dbufstat -bxn -i "$DBUFS_FILE" "$filter" | wc -l)
 
 	within_tolerance $from_dbufstat $from_dbufs 15 \
@@ -71,8 +77,8 @@ log_onexit cleanup
 log_must file_write -o create -f "$TESTDIR/file" -b 1048576 -c 20 -d R
 log_must zpool sync
 
-log_must eval "cat /proc/spl/kstat/zfs/dbufs > $DBUFS_FILE"
-log_must eval "cat /proc/spl/kstat/zfs/dbufstats > $DBUFSTATS_FILE"
+log_must eval "kstat dbufs > $DBUFS_FILE"
+log_must eval "kstat dbufstats '' > $DBUFSTATS_FILE"
 
 for level in {0..11}; do
 	testdbufstat "cache_level_$level" "dbc=1,level=$level"
diff --git a/tests/zfs-tests/tests/functional/arc/dbufstats_002_pos.ksh b/tests/zfs-tests/tests/functional/arc/dbufstats_002_pos.ksh
index dc30b6606..58d401539 100755
--- a/tests/zfs-tests/tests/functional/arc/dbufstats_002_pos.ksh
+++ b/tests/zfs-tests/tests/functional/arc/dbufstats_002_pos.ksh
@@ -58,10 +58,10 @@ log_onexit cleanup
 log_must file_write -o create -f "$TESTDIR/file" -b 1048576 -c 1 -d R
 log_must zpool sync
 
-objid=$(stat --format="%i" "$TESTDIR/file")
+objid=$(get_objnum "$TESTDIR/file")
 log_note "Object ID for $TESTDIR/file is $objid"
 
-log_must eval "cat /proc/spl/kstat/zfs/dbufs > $DBUFS_FILE"
+log_must eval "kstat dbufs > $DBUFS_FILE"
 dbuf=$(dbufstat -bxn -i "$DBUFS_FILE" -F "object=$objid" | wc -l)
 mru=$(dbufstat -bxn -i "$DBUFS_FILE" -F "object=$objid,list=1" | wc -l)
 mfu=$(dbufstat -bxn -i "$DBUFS_FILE" -F "object=$objid,list=3" | wc -l)
@@ -70,7 +70,7 @@ verify_ne "0" "$mru" "mru count"
 verify_eq "0" "$mfu" "mfu count"
 
 log_must eval "cat $TESTDIR/file > /dev/null"
-log_must eval "cat /proc/spl/kstat/zfs/dbufs > $DBUFS_FILE"
+log_must eval "kstat dbufs > $DBUFS_FILE"
 dbuf=$(dbufstat -bxn -i "$DBUFS_FILE" -F "object=$objid" | wc -l)
 mru=$(dbufstat -bxn -i "$DBUFS_FILE" -F "object=$objid,list=1" | wc -l)
 mfu=$(dbufstat -bxn -i "$DBUFS_FILE" -F "object=$objid,list=3" | wc -l)