Fix intra-pool resumable 'zfs send -t <token>'

Because resuming from a token requires "guid" -> "snapshot" mapping
we have to walk the whole dataset hierarchy to find the right snapshot
to send; when both source and destination exists, for an incremental
resumable stream, libzfs gets confused and picks up the wrong snapshot
to send from: this results in attempting to send

   "destination@snap1 -> source@snap2"

instead of

   "source@snap1 -> source@snap2"

which fails with a "Invalid cross-device link" error (EXDEV).

Fix this by adjusting the logic behind dataset traversal in
zfs_iter_children() to pick the right snapshot to send from.

Additionally update dry-run 'zfs send -t' to print its output to
stderr: this is consistent with other dry-run commands.

Reviewed-by: George Melikov <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: loli10K <[email protected]>
Closes #6618
Closes #6619
Closes #6623 

7 files changed, 12 insertions, 12 deletions

diff --git a/tests/zfs-tests/tests/functional/rsend/rsend.kshlib b/tests/zfs-tests/tests/functional/rsend/rsend.kshlib
index 7c4b2f07f..909cd1677 100644
--- a/tests/zfs-tests/tests/functional/rsend/rsend.kshlib
+++ b/tests/zfs-tests/tests/functional/rsend/rsend.kshlib
@@ -505,11 +505,13 @@ function test_fs_setup
 {
 	typeset sendfs=$1
 	typeset recvfs=$2
+	typeset streamfs=$3
 	typeset sendpool=${sendfs%%/*}
 	typeset recvpool=${recvfs%%/*}
 
 	datasetexists $sendfs && log_must_busy zfs destroy -r $sendpool
 	datasetexists $recvfs && log_must_busy zfs destroy -r $recvpool
+	datasetexists $streamfs && log_must_busy zfs destroy -r $streamfs
 
 	if $(datasetexists $sendfs || zfs create -o compress=lz4 $sendfs); then
 		mk_files 1000 256 0 $sendfs &
@@ -538,10 +540,7 @@ function test_fs_setup
 		    ">/$sendpool/incremental.zsend"
 	fi
 
-	if datasetexists $streamfs; then
-		log_must_busy zfs destroy -r $streamfs
-	fi
-	log_must zfs create -o compress=lz4 $sendpool/stream
+	log_must zfs create -o compress=lz4 $streamfs
 }
 
 #
@@ -655,9 +654,10 @@ function resume_cleanup
 {
 	typeset sendfs=$1
 	typeset streamfs=$2
+	typeset sendpool=${sendfs%%/*}
 
 	datasetexists $sendfs && log_must_busy zfs destroy -r $sendfs
 	datasetexists $streamfs && log_must_busy zfs destroy -r $streamfs
 	cleanup_pool $POOL2
-	rm -f /$POOL/initial.zsend /$POOL/incremental.zsend
+	rm -f /$sendpool/initial.zsend /$sendpool/incremental.zsend
 }
diff --git a/tests/zfs-tests/tests/functional/rsend/rsend_019_pos.ksh b/tests/zfs-tests/tests/functional/rsend/rsend_019_pos.ksh
index f76bce9d0..1a39832a1 100755
--- a/tests/zfs-tests/tests/functional/rsend/rsend_019_pos.ksh
+++ b/tests/zfs-tests/tests/functional/rsend/rsend_019_pos.ksh
@@ -48,8 +48,8 @@ sendfs=$POOL/sendfs
 recvfs=$POOL3/recvfs
 streamfs=$POOL2/stream
 
-for sendfs in $POOL2/sendfs $POOL2; do
-	test_fs_setup $sendfs $recvfs
+for sendfs in $POOL2/sendfs $POOL3; do
+	test_fs_setup $sendfs $recvfs $streamfs
 	resume_test "zfs send -v $sendfs@a" $streamfs $recvfs
 	resume_test "zfs send -v -i @a $sendfs@b" $streamfs $recvfs
 	file_check $sendfs $recvfs
diff --git a/tests/zfs-tests/tests/functional/rsend/rsend_020_pos.ksh b/tests/zfs-tests/tests/functional/rsend/rsend_020_pos.ksh
index 9f1530b45..a6474a4e5 100755
--- a/tests/zfs-tests/tests/functional/rsend/rsend_020_pos.ksh
+++ b/tests/zfs-tests/tests/functional/rsend/rsend_020_pos.ksh
@@ -47,7 +47,7 @@ streamfs=$POOL/stream
 
 log_onexit resume_cleanup $sendfs $streamfs
 
-test_fs_setup $sendfs $recvfs
+test_fs_setup $sendfs $recvfs $streamfs
 resume_test "zfs send -D -v $sendfs@a" $streamfs $recvfs
 file_check $sendfs $recvfs
 
diff --git a/tests/zfs-tests/tests/functional/rsend/rsend_021_pos.ksh b/tests/zfs-tests/tests/functional/rsend/rsend_021_pos.ksh
index 54d56c9a6..47b9fdcb6 100755
--- a/tests/zfs-tests/tests/functional/rsend/rsend_021_pos.ksh
+++ b/tests/zfs-tests/tests/functional/rsend/rsend_021_pos.ksh
@@ -49,7 +49,7 @@ streamfs=$POOL/stream
 
 log_onexit resume_cleanup $sendfs $streamfs
 
-test_fs_setup $sendfs $recvfs
+test_fs_setup $sendfs $recvfs $streamfs
 resume_test "zfs send -v -e $sendfs@a" $streamfs $recvfs
 resume_test "zfs send -v -e -i @a $sendfs@b" $streamfs $recvfs
 file_check $sendfs $recvfs
diff --git a/tests/zfs-tests/tests/functional/rsend/rsend_022_pos.ksh b/tests/zfs-tests/tests/functional/rsend/rsend_022_pos.ksh
index ff51fecaf..28e19b5ec 100755
--- a/tests/zfs-tests/tests/functional/rsend/rsend_022_pos.ksh
+++ b/tests/zfs-tests/tests/functional/rsend/rsend_022_pos.ksh
@@ -52,7 +52,7 @@ streamfs=$POOL/stream
 
 log_onexit resume_cleanup $sendfs $streamfs
 
-test_fs_setup $sendfs $recvfs
+test_fs_setup $sendfs $recvfs $streamfs
 log_must zfs bookmark $sendfs@a $sendfs#bm_a
 log_must_busy zfs destroy $sendfs@a
 log_must zfs receive -v $recvfs </$POOL/initial.zsend
diff --git a/tests/zfs-tests/tests/functional/rsend/rsend_024_pos.ksh b/tests/zfs-tests/tests/functional/rsend/rsend_024_pos.ksh
index fcb5ecf22..9f77f1d5d 100755
--- a/tests/zfs-tests/tests/functional/rsend/rsend_024_pos.ksh
+++ b/tests/zfs-tests/tests/functional/rsend/rsend_024_pos.ksh
@@ -49,7 +49,7 @@ streamfs=$POOL/stream
 
 log_onexit resume_cleanup $sendfs $streamfs
 
-test_fs_setup $sendfs $recvfs
+test_fs_setup $sendfs $recvfs $streamfs
 log_must zfs unmount -f $sendfs
 resume_test "zfs send $sendfs" $streamfs $recvfs
 file_check $sendfs $recvfs
diff --git a/tests/zfs-tests/tests/functional/rsend/send-c_resume.ksh b/tests/zfs-tests/tests/functional/rsend/send-c_resume.ksh
index 9f43b7929..d8d7c40e4 100755
--- a/tests/zfs-tests/tests/functional/rsend/send-c_resume.ksh
+++ b/tests/zfs-tests/tests/functional/rsend/send-c_resume.ksh
@@ -41,7 +41,7 @@ streamfs=$POOL/stream
 log_assert "Verify compressed send streams can be resumed if interrupted"
 log_onexit resume_cleanup $sendfs $streamfs
 
-test_fs_setup $sendfs $recvfs
+test_fs_setup $sendfs $recvfs $streamfs
 resume_test "zfs send -c -v $sendfs@a" $streamfs $recvfs
 resume_test "zfs send -c -v -i @a $sendfs@b" $streamfs $recvfs
 file_check $sendfs $recvfs