ZTS: Waiting for zvols to be available

The ZTS block_device_wait helper function should use -e when waiting
for a file to appear since it will be either a block special device
or a symlink.  This didn't cause any failures but when a device path
was specified the function would wait longer than needed.

Additionally update the most flakey test cases to pass the file path
to block_device_wait to try and improve the test reliability.  The
udev behavior on Fedora in particular can result in frequent false
positives.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #12515

tests/zfs-tests/include/blkdev.shlib

@@ -93,7 +93,7 @@ function block_device_wait
 		typeset missing=false
 		typeset dev
 		for dev in "${@}"; do
-			if ! [[ -f $dev ]]; then
+			if ! [[ -e $dev ]]; then
 				missing=true
 				break
 			fi

tests/zfs-tests/tests/functional/cli_root/zfs_copies/zfs_copies.kshlib

@@ -87,7 +87,7 @@ function do_vol_test
 
 	log_must zfs create -V $VOLSIZE -o copies=$copies $vol
 	log_must zfs set refreservation=none $vol
-	block_device_wait
+	block_device_wait $vol_r_path
 
 	case "$type" in
 	"ext2")

tests/zfs-tests/tests/functional/cli_root/zfs_rename/zfs_rename_007_pos.ksh

@@ -117,26 +117,26 @@ log_must diff $SRC_FILE $obj
 if is_global_zone; then
 	vol=$TESTPOOL/$TESTFS/vol.$$ ;	volclone=$TESTPOOL/$TESTFS/volclone.$$
 	log_must zfs create -V 100M $vol
-	block_device_wait
 
 	obj=$(target_obj $vol)
+	block_device_wait $obj
 	log_must dd if=$SRC_FILE of=$obj bs=$BS count=$CNT
 
 	snap=${vol}@snap.$$
 	log_must zfs snapshot $snap
 	log_must zfs clone $snap $volclone
-	block_device_wait
 
 	# Rename dataset & clone
 	log_must zfs rename $vol ${vol}-new
 	log_must zfs rename $volclone ${volclone}-new
-	block_device_wait
 
 	# Compare source file and target file
 	obj=$(target_obj ${vol}-new)
+	block_device_wait $obj
 	log_must dd if=$obj of=$DST_FILE bs=$BS count=$CNT
 	log_must diff $SRC_FILE $DST_FILE
 	obj=$(target_obj ${volclone}-new)
+	block_device_wait $obj
 	log_must dd if=$obj of=$DST_FILE bs=$BS count=$CNT
 	log_must diff $SRC_FILE $DST_FILE
 
@@ -144,10 +144,10 @@ if is_global_zone; then
 	log_must zfs rename ${vol}-new $vol
 	log_must zfs rename $snap ${snap}-new
 	log_must zfs clone ${snap}-new $volclone
-	block_device_wait
 
 	# Compare source file and target file
 	obj=$(target_obj $volclone)
+	block_device_wait $obj
 	log_must dd if=$obj of=$DST_FILE bs=$BS count=$CNT
 	log_must diff $SRC_FILE $DST_FILE
 fi

tests/zfs-tests/tests/functional/rsend/recv_dedup_encrypted_zvol.ksh

@@ -52,7 +52,7 @@ log_must eval "bzcat <$sendfile_compressed >$sendfile"
 log_must eval "zstream redup $sendfile | zfs recv $TESTPOOL/recv"
 
 log_must zfs load-key $TESTPOOL/recv
-block_device_wait
+block_device_wait $volfile
 
 log_must eval "bzcat <$volfile_compressed >$volfile"
 log_must diff $volfile $recvdev

tests/zfs-tests/tests/functional/rsend/send-c_stream_size_estimate.ksh

@@ -65,7 +65,7 @@ for compress in "${compress_prop_vals[@]}"; do
 	datasetexists $send_vol && log_must_busy zfs destroy -r $send_vol
 	log_must zfs create -o compress=$compress $send_ds
 	log_must zfs create -V 1g -o compress=$compress $send_vol
-	block_device_wait
+	block_device_wait $send_voldev
 
 	typeset dir=$(get_prop mountpoint $send_ds)
 	log_must cp $file $dir

tests/zfs-tests/tests/functional/zvol/zvol_swap/zvol_swap_004_pos.ksh

@@ -62,7 +62,7 @@ for vbs in 8192 16384 32768 65536 131072; do
 
 		# Create a sparse volume to test larger sizes
 		log_must zfs create -s -b $vbs -V $volsize $vol
-		block_device_wait
+		block_device_wait $swapname
 		log_must swap_setup $swapname
 
 		new_volsize=$(get_prop volsize $vol)