ZTS: avoid piping to special devices

As described in #11445, the kernel interface kernel_{read,write} no
longer act on special devices.  In the ZTS, zfs send and receive are
tested by piping to these devices, leading to spurious failures (for
positive tests) and may mask errors (for negative tests).

Until a more permanent mechanism to address this deficiency is
developed, clean up the output from the ZTS by avoiding directly piping
to or from /dev/null and /dev/zero.

For /dev/zero input, simply use a pipe: `cat </dev/zero |` .

However, for /dev/null output, the shell semantics for pipe failures
means that zfs send error codes will be masked by the successful
`| cat >/dev/null` command execution.  In that case, use a temporary
file under $TEST_BASE_DIR for output in favor.

Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Attila Fülöp <[email protected]>
Signed-off-by: Antonio Russo <[email protected]>
Closes #11478 

13 files changed, 31 insertions, 31 deletions

diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_receive/zfs_receive_005_neg.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_receive/zfs_receive_005_neg.ksh
index 4cbc7e339..ce89c6835 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_receive/zfs_receive_005_neg.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_receive/zfs_receive_005_neg.ksh
@@ -82,8 +82,8 @@ log_must zfs snapshot $init_snap
 log_must eval "zfs send $init_snap > $full_bkup"
 
 log_note "'zfs receive' fails with invalid send streams."
-log_mustnot eval "zfs receive $rst_init_snap < /dev/zero"
-log_mustnot eval "zfs receive -d $rst_root </dev/zero"
+log_mustnot eval "cat </dev/zero | zfs receive $rst_init_snap"
+log_mustnot eval "cat </dev/zero | zfs receive -d $rst_root"
 
 log_must eval "zfs receive $rst_init_snap < $full_bkup"
 
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send-b.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send-b.ksh
index 87997e76c..2105bc4d2 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send-b.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send-b.ksh
@@ -58,13 +58,13 @@ log_must zfs set "org.openzfs:snapprop=val" "$SENDFS@s1"
 # 2. Verify command line options interact with '-b' correctly
 typeset opts=("" "p" "Rp" "cew" "nv" "D" "DLPRcenpvw")
 for opt in ${opts[@]}; do
-	log_must eval "zfs send -b$opt $SENDFS@s1 > /dev/null"
-	log_must eval "zfs send -b$opt -i $SENDFS@s1 $SENDFS@s2 > /dev/null"
-	log_must eval "zfs send -b$opt -I $SENDFS@s1 $SENDFS@s2 > /dev/null"
+	log_must eval "zfs send -b$opt $SENDFS@s1 >$TEST_BASE_DIR/devnull"
+	log_must eval "zfs send -b$opt -i $SENDFS@s1 $SENDFS@s2 >$TEST_BASE_DIR/devnull"
+	log_must eval "zfs send -b$opt -I $SENDFS@s1 $SENDFS@s2 >$TEST_BASE_DIR/devnull"
 done
 for opt in ${opts[@]}; do
-	log_mustnot eval "zfs send -b$opt $SENDFS > /dev/null"
-	log_mustnot eval "zfs send -b$opt $SENDFS#bm > /dev/null"
+	log_mustnot eval "zfs send -b$opt $SENDFS >$TEST_BASE_DIR/devnull"
+	log_mustnot eval "zfs send -b$opt $SENDFS#bm >$TEST_BASE_DIR/devnull"
 done
 
 # Do 3..6 in a loop to verify various combination of "zfs send" options
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_003_pos.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_003_pos.ksh
index 825a10d0f..0b55254f7 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_003_pos.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_003_pos.ksh
@@ -61,7 +61,7 @@ log_must zfs snapshot $snap2
 
 typeset -i i=0
 while (( i < ${#args[*]} )); do
-	log_must eval "zfs send -i ${args[i]} > /dev/null"
+	log_must eval "zfs send -i ${args[i]} >$TEST_BASE_DIR/devnull"
 
 	(( i += 1 ))
 done
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_004_neg.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_004_neg.ksh
index 4a9d29fce..dfa9fc251 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_004_neg.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_004_neg.ksh
@@ -96,7 +96,7 @@ log_must zfs snapshot $snap3
 typeset -i i=0
 while (( i < ${#badargs[*]} ))
 do
-	log_mustnot eval "zfs send ${badargs[i]} >/dev/null"
+	log_mustnot eval "zfs send ${badargs[i]} >$TEST_BASE_DIR/devnull"
 
 	(( i = i + 1 ))
 done
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_005_pos.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_005_pos.ksh
index 9f369e372..c9e37cbba 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_005_pos.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_005_pos.ksh
@@ -61,6 +61,6 @@ log_must zfs snapshot -r $TESTPOOL@snap
 log_must zpool export $TESTPOOL
 log_must zpool import -o readonly=on $TESTPOOL
 
-log_must eval "zfs send -R $TESTPOOL@snap >/dev/null"
+log_must eval "zfs send -R $TESTPOOL@snap >$TEST_BASE_DIR/devnull"
 
 log_pass "'zfs send -R' can send from read-only pools"
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted.ksh
index 490e146ba..1e63b29ad 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted.ksh
@@ -62,15 +62,15 @@ log_must eval "echo $passphrase1 | zfs create -o encryption=on" \
 
 log_must zfs snapshot -r $snap
 
-log_must eval "zfs send $snap > /dev/null"
-log_mustnot eval "zfs send -p $snap > /dev/null"
-log_mustnot eval "zfs send -R $snap > /dev/null"
+log_must eval "zfs send $snap >$TEST_BASE_DIR/devnull"
+log_mustnot eval "zfs send -p $snap >$TEST_BASE_DIR/devnull"
+log_mustnot eval "zfs send -R $snap >$TEST_BASE_DIR/devnull"
 
 log_must zfs unmount $TESTPOOL/$TESTFS1
 log_must zfs unload-key $TESTPOOL/$TESTFS1
 
-log_mustnot eval "zfs send $snap > /dev/null"
-log_must eval "zfs send $TESTPOOL/$TESTFS1/child@snap > /dev/null"
+log_mustnot eval "zfs send $snap >$TEST_BASE_DIR/devnull"
+log_must eval "zfs send $TESTPOOL/$TESTFS1/child@snap >$TEST_BASE_DIR/devnull"
 
 log_pass "ZFS performs unencrypted sends of encrypted datasets, unless the" \
 	"'-p' or '-R' options are specified"
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted_unloaded.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted_unloaded.ksh
index 112ee1143..9d59494fc 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted_unloaded.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted_unloaded.ksh
@@ -53,7 +53,7 @@ log_must eval "echo $passphrase | zfs create -o encryption=on" \
 log_must zfs snapshot $snap
 log_must zfs unmount $TESTPOOL/$TESTFS1
 log_must zfs unload-key $TESTPOOL/$TESTFS1
-log_mustnot eval "zfs send $snap > /dev/null"
+log_mustnot eval "zfs send $snap >$TEST_BASE_DIR/devnull"
 
 log_pass "ZFS does not perform unencrypted sends from encrypted datasets" \
 	"with unloaded keys."
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_raw.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_raw.ksh
index 85cc7407e..065eea3eb 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_raw.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_raw.ksh
@@ -59,21 +59,21 @@ log_must eval "echo $passphrase | zfs create -o encryption=on" \
 log_must zfs snapshot $snap
 log_must zfs snapshot $snap1
 
-log_must eval "zfs send -w $snap > /dev/null"
-log_must eval "zfs send -w $snap1 > /dev/null"
+log_must eval "zfs send -w $snap >$TEST_BASE_DIR/devnull"
+log_must eval "zfs send -w $snap1 >$TEST_BASE_DIR/devnull"
 
 log_note "Verify ZFS can perform raw sends with properties"
-log_must eval "zfs send -wp $snap > /dev/null"
-log_must eval "zfs send -wp $snap1 > /dev/null"
+log_must eval "zfs send -wp $snap >$TEST_BASE_DIR/devnull"
+log_must eval "zfs send -wp $snap1 >$TEST_BASE_DIR/devnull"
 
 log_note "Verify ZFS can perform raw replication sends"
-log_must eval "zfs send -wR $snap > /dev/null"
-log_must eval "zfs send -wR $snap1 > /dev/null"
+log_must eval "zfs send -wR $snap >$TEST_BASE_DIR/devnull"
+log_must eval "zfs send -wR $snap1 >$TEST_BASE_DIR/devnull"
 
 log_note "Verify ZFS can perform a raw send of an encrypted datasets with" \
 	"its key unloaded"
 log_must zfs unmount $TESTPOOL/$TESTFS1
 log_must zfs unload-key $TESTPOOL/$TESTFS1
-log_must eval "zfs send -w $snap1 > /dev/null"
+log_must eval "zfs send -w $snap1 >$TEST_BASE_DIR/devnull"
 
 log_pass "ZFS performs raw sends of datasets"
diff --git a/tests/zfs-tests/tests/functional/redacted_send/redacted_negative.ksh b/tests/zfs-tests/tests/functional/redacted_send/redacted_negative.ksh
index 432460fa2..e591cca0b 100755
--- a/tests/zfs-tests/tests/functional/redacted_send/redacted_negative.ksh
+++ b/tests/zfs-tests/tests/functional/redacted_send/redacted_negative.ksh
@@ -45,11 +45,11 @@ log_must zfs snapshot $clone2@snap
 
 # Incompatible flags
 log_must zfs redact $sendfs@snap2 book $clone1@snap
-log_mustnot eval "zfs send -R --redact book $sendfs@snap2 >/dev/null"
+log_mustnot eval "zfs send -R --redact book $sendfs@snap2 >$TEST_BASE_DIR/devnull"
 
 typeset arg
 for arg in "$sendfs" "$clone1#book"; do
-	log_mustnot eval "zfs send --redact book $arg >/dev/null"
+	log_mustnot eval "zfs send --redact book $arg >$TEST_BASE_DIR/devnull"
 done
 
 # Bad redaction list arguments
@@ -58,7 +58,7 @@ log_mustnot zfs redact $sendfs@snap1 book
 log_mustnot zfs redact $sendfs#book1 book4 $clone1
 log_mustnot zfs redact $sendfs@snap1 book snap2 snap3
 log_mustnot zfs redact $sendfs@snap1 book @snap2 @snap3
-log_mustnot eval "zfs send --redact $sendfs#book $sendfs@snap >/dev/null"
+log_mustnot eval "zfs send --redact $sendfs#book $sendfs@snap >$TEST_BASE_DIR/devnull"
 
 # Redaction snapshots not a descendant of tosnap
 log_mustnot zfs redact $sendfs@snap2 book $sendfs@snap2
@@ -66,7 +66,7 @@ log_must zfs redact $sendfs@snap2 book2 $clone1@snap $clone2@snap
 log_must eval "zfs send --redact book2 $sendfs@snap2 >$stream"
 log_must zfs redact $sendfs@snap2 book3 $clone1@snap $clone2@snap
 log_must eval "zfs send -i $sendfs@snap1 --redact book3 $sendfs@snap2 \
-    >/dev/null"
+    >$TEST_BASE_DIR/devnull"
 log_mustnot zfs redact $sendfs@snap3 $sendfs@snap3 $clone1@snap
 
 # Full redacted sends of redacted datasets are not allowed.
diff --git a/tests/zfs-tests/tests/functional/redacted_send/redacted_resume.ksh b/tests/zfs-tests/tests/functional/redacted_send/redacted_resume.ksh
index 8118ea59e..4ab04a0e5 100755
--- a/tests/zfs-tests/tests/functional/redacted_send/redacted_resume.ksh
+++ b/tests/zfs-tests/tests/functional/redacted_send/redacted_resume.ksh
@@ -81,7 +81,7 @@ log_must eval "zfs send --redact book1 $sendfs@snap >$stream"
 dd if=$stream bs=64k count=1 | log_mustnot zfs receive -s $recvfs
 [[ "-" = $(get_prop receive_resume_token $recvfs) ]] && \
     log_fail "Receive token not found."
-log_mustnot eval "zfs send --saved --redact book1 $recvfs > /dev/null"
+log_mustnot eval "zfs send --saved --redact book1 $recvfs >$TEST_BASE_DIR/devnull"
 log_must zfs recv -A $recvfs
 log_must datasetnonexists $recvfs
 
diff --git a/tests/zfs-tests/tests/functional/removal/removal_with_send.ksh b/tests/zfs-tests/tests/functional/removal/removal_with_send.ksh
index 59e66aca5..a08247838 100755
--- a/tests/zfs-tests/tests/functional/removal/removal_with_send.ksh
+++ b/tests/zfs-tests/tests/functional/removal/removal_with_send.ksh
@@ -28,7 +28,7 @@ function callback
 {
 	create_snapshot $TESTPOOL/$TESTFS $TESTSNAP
 	log_must ksh -c \
-	    "zfs send $TESTPOOL/$TESTFS@$TESTSNAP >/dev/null"
+	    "zfs send $TESTPOOL/$TESTFS@$TESTSNAP >$TEST_BASE_DIR/devnull"
 	return 0
 }
 
diff --git a/tests/zfs-tests/tests/functional/rsend/send_invalid.ksh b/tests/zfs-tests/tests/functional/rsend/send_invalid.ksh
index a0abe64b4..2ce7ee4a0 100755
--- a/tests/zfs-tests/tests/functional/rsend/send_invalid.ksh
+++ b/tests/zfs-tests/tests/functional/rsend/send_invalid.ksh
@@ -44,7 +44,7 @@ log_must zfs snap $testfs@snap0
 log_must zfs snap $testfs@snap1
 
 # Test bad send with the CLI
-log_mustnot eval "zfs send -i $testfs@snap1 $testfs@snap0 >/dev/null"
+log_mustnot eval "zfs send -i $testfs@snap1 $testfs@snap0 >$TEST_BASE_DIR/devnull"
 
 # Test bad send with libzfs/libzfs_core
 log_must badsend $testfs@snap0 $testfs@snap1
diff --git a/tests/zfs-tests/tests/functional/rsend/send_partial_dataset.ksh b/tests/zfs-tests/tests/functional/rsend/send_partial_dataset.ksh
index d5eb9a0ed..c390327a5 100755
--- a/tests/zfs-tests/tests/functional/rsend/send_partial_dataset.ksh
+++ b/tests/zfs-tests/tests/functional/rsend/send_partial_dataset.ksh
@@ -103,7 +103,7 @@ set -A badargs \
 
 while (( i < ${#badargs[*]} ))
 do
-	log_mustnot eval "zfs send --saved ${badargs[i]} >/dev/null"
+	log_mustnot eval "zfs send --saved ${badargs[i]} >$TEST_BASE_DIR/devnull"
 	(( i = i + 1 ))
 done