[Libguestfs] [nbdkit PATCH 3/4] tests: Don't let test-parallel-* hang on nbdkit bug

[Eric Blake]

If nbdkit has a bug (such as the nbd-standalone bug fixed in the
previous commit), qemu-io ends up waiting forever rather than
realizing that if the server disappears unexpectedly then qemu-io
should quit.  So add timeouts so the testsuite will flag the problem
instead of hang (tested by reordering this commit before the
previous).

It's trickier than I expected: from the command line, 'timeout 10s
qemu-io ...' works just fine, but from a script, it fails.  Why?
Because timeout defaults to creating a new process group when run
non-interactively, but qemu-io is generally an interactive program
that expects to be able to modify the terminal settings when stdin is
a terminal, even when it will not be reading from stdin because of the
use of -c.  When stdin is inherited but no longer the controlling
terminal because of timeout's new process group, qemu-io fails to make
progress. As solutions, we can either use 'timeout --foreground', or
redirect stdin to something that is not a terminal; this patch uses
the latter.

Signed-off-by: Eric Blake <eblake at redhat.com>
---
 tests/test-parallel-file.sh | 19 ++++++++++---------
 tests/test-parallel-nbd.sh  | 13 ++++++++-----
 tests/test-parallel-sh.sh   | 19 ++++++++++---------
 3 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/tests/test-parallel-file.sh b/tests/test-parallel-file.sh
index 20276d48..136c2db5 100755
--- a/tests/test-parallel-file.sh
+++ b/tests/test-parallel-file.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 # nbdkit
-# Copyright (C) 2017-2019 Red Hat Inc.
+# Copyright (C) 2017-2020 Red Hat Inc.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
@@ -35,6 +35,7 @@ source ./functions.sh
 # Check file-data was created by Makefile and qemu-io exists.
 requires test -f file-data
 requires qemu-io --version
+requires timeout --version

 nbdkit --dump-plugin file | grep -q ^thread_model=parallel ||
     { echo "nbdkit lacks support for parallel requests"; exit 77; }
@@ -43,8 +44,8 @@ cleanup_fn rm -f test-parallel-file.data test-parallel-file.out

 # Populate file, and sanity check that qemu-io can issue parallel requests
 printf '%1024s' . > test-parallel-file.data
-qemu-io -f raw -c "aio_write -P 1 0 512" -c "aio_write -P 2 512 512" \
-         -c aio_flush test-parallel-file.data ||
+timeout 10s </dev/null qemu-io -f raw -c "aio_write -P 1 0 512" \
+        -c "aio_write -P 2 512 512" -c aio_flush test-parallel-file.data ||
     { echo "'qemu-io' can't drive parallel requests"; exit 77; }

 # Set up the file plugin to delay both reads and writes (for a good chance
@@ -55,8 +56,8 @@ qemu-io -f raw -c "aio_write -P 1 0 512" -c "aio_write -P 2 512 512" \

 # With --threads=1, the write should complete first because it was issued first
 nbdkit -v -t 1 -U - --filter=delay file test-parallel-file.data \
-  wdelay=2 rdelay=1 --run 'qemu-io -f raw -c "aio_write -P 2 512 512" \
-                           -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
+  wdelay=2 rdelay=1 --run 'timeout 10s </dev/null qemu-io -f raw \
+    -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
     tee test-parallel-file.out
 if test "$(grep '512/512' test-parallel-file.out)" != \
 "wrote 512/512 bytes at offset 512
@@ -66,8 +67,8 @@ fi

 # With default --threads, the faster read should complete first
 nbdkit -v -U - --filter=delay file test-parallel-file.data \
-  wdelay=2 rdelay=1 --run 'qemu-io -f raw -c "aio_write -P 2 512 512" \
-                           -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
+  wdelay=2 rdelay=1 --run 'timeout 10s </dev/null qemu-io -f raw \
+    -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
     tee test-parallel-file.out
 if test "$(grep '512/512' test-parallel-file.out)" != \
 "read 512/512 bytes at offset 0
@@ -77,8 +78,8 @@ fi

 # With --filter=noparallel, the write should complete first because it was issued first
 nbdkit -v -U - --filter=noparallel --filter=delay file test-parallel-file.data \
-  wdelay=2 rdelay=1 --run 'qemu-io -f raw -c "aio_write -P 2 512 512" \
-                           -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
+  wdelay=2 rdelay=1 --run 'timeout 10s </dev/null qemu-io -f raw \
+    -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
     tee test-parallel-file.out
 if test "$(grep '512/512' test-parallel-file.out)" != \
 "wrote 512/512 bytes at offset 512
diff --git a/tests/test-parallel-nbd.sh b/tests/test-parallel-nbd.sh
index 4e546df4..1fdf7df4 100755
--- a/tests/test-parallel-nbd.sh
+++ b/tests/test-parallel-nbd.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 # nbdkit
-# Copyright (C) 2017-2019 Red Hat Inc.
+# Copyright (C) 2017-2020 Red Hat Inc.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
@@ -35,6 +35,7 @@ source ./functions.sh
 # Check file-data was created by Makefile and qemu-io exists.
 requires test -f file-data
 requires qemu-io --version
+requires timeout --version

 nbdkit --dump-plugin nbd | grep -q ^thread_model=parallel ||
     { echo "nbdkit lacks support for parallel requests"; exit 77; }
@@ -46,8 +47,8 @@ cleanup_fn rm -f $files

 # Populate file, and sanity check that qemu-io can issue parallel requests
 printf '%1024s' . > test-parallel-nbd.data
-qemu-io -f raw -c "aio_write -P 1 0 512" -c "aio_write -P 2 512 512" \
-         -c aio_flush test-parallel-nbd.data ||
+timeout 10s </dev/null qemu-io -f raw -c "aio_write -P 1 0 512" \
+        -c "aio_write -P 2 512 512" -c aio_flush test-parallel-nbd.data ||
     { echo "'qemu-io' can't drive parallel requests"; exit 77; }

 # Set up the file plugin to delay both reads and writes (for a good chance
@@ -63,7 +64,8 @@ start_nbdkit -P test-parallel-nbd.pid \

 # With --threads=1, the write should complete first because it was issued first
 nbdkit -v -t 1 -U - nbd socket=$sock --run '
-  qemu-io -f raw -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" \
+  timeout 10s </dev/null qemu-io -f raw \
+  -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" \
   -c aio_flush $nbd' | tee test-parallel-nbd.out
 if test "$(grep '512/512' test-parallel-nbd.out)" != \
 "wrote 512/512 bytes at offset 512
@@ -73,7 +75,8 @@ fi

 # With default --threads, the faster read should complete first
 nbdkit -v -U - nbd socket=$sock --run '
-  qemu-io -f raw -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" \
+  timeout 10s </dev/null qemu-io -f raw \
+  -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" \
   -c aio_flush $nbd' | tee test-parallel-nbd.out
 if test "$(grep '512/512' test-parallel-nbd.out)" != \
 "read 512/512 bytes at offset 0
diff --git a/tests/test-parallel-sh.sh b/tests/test-parallel-sh.sh
index 15d8875d..4cc93c33 100755
--- a/tests/test-parallel-sh.sh
+++ b/tests/test-parallel-sh.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 # nbdkit
-# Copyright (C) 2017-2019 Red Hat Inc.
+# Copyright (C) 2017-2020 Red Hat Inc.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
@@ -35,6 +35,7 @@ source ./functions.sh
 # Check file-data was created by Makefile and qemu-io exists.
 requires test -f file-data
 requires qemu-io --version
+requires timeout --version

 nbdkit --dump-plugin sh | grep -q ^thread_model=parallel ||
     { echo "nbdkit lacks support for parallel requests"; exit 77; }
@@ -43,8 +44,8 @@ cleanup_fn rm -f test-parallel-sh.data test-parallel-sh.out test-parallel-sh.scr

 # Populate file, and sanity check that qemu-io can issue parallel requests
 printf '%1024s' . > test-parallel-sh.data
-qemu-io -f raw -c "aio_write -P 1 0 512" -c "aio_write -P 2 512 512" \
-         -c aio_flush test-parallel-sh.data ||
+timeout 10s </dev/null qemu-io -f raw -c "aio_write -P 1 0 512" \
+        -c "aio_write -P 2 512 512" -c aio_flush test-parallel-sh.data ||
     { echo "'qemu-io' can't drive parallel requests"; exit 77; }

 # Set up the sh plugin to delay both reads and writes (for a good
@@ -96,8 +97,8 @@ chmod +x test-parallel-sh.script

 # With --threads=1, the write should complete first because it was issued first
 nbdkit -v -t 1 -U - --filter=delay sh test-parallel-sh.script \
-  wdelay=2 rdelay=1 --run 'qemu-io -f raw -c "aio_write -P 2 512 512" \
-                           -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
+  wdelay=2 rdelay=1 --run 'timeout 10s </dev/null qemu-io -f raw \
+    -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
     tee test-parallel-sh.out
 if test "$(grep '512/512' test-parallel-sh.out)" != \
 "wrote 512/512 bytes at offset 512
@@ -107,8 +108,8 @@ fi

 # With default --threads, the faster read should complete first
 nbdkit -v -U - --filter=delay sh test-parallel-sh.script \
-  wdelay=2 rdelay=1 --run 'qemu-io -f raw -c "aio_write -P 2 512 512" \
-                           -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
+  wdelay=2 rdelay=1 --run 'timeout 10s </dev/null qemu-io -f raw \
+    -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
     tee test-parallel-sh.out
 if test "$(grep '512/512' test-parallel-sh.out)" != \
 "read 512/512 bytes at offset 0
@@ -120,8 +121,8 @@ fi
 # issued first. Also test that the log filter doesn't leak an fd
 nbdkit -v -U - --filter=noparallel --filter=log --filter=delay \
   sh test-parallel-sh.script logfile=/dev/null \
-  wdelay=2 rdelay=1 --run 'qemu-io -f raw -c "aio_write -P 2 512 512" \
-                           -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
+  wdelay=2 rdelay=1 --run 'timeout 10s </dev/null qemu-io -f raw \
+    -c "aio_write -P 2 512 512" -c "aio_read -P 1 0 512" -c aio_flush $nbd' |
     tee test-parallel-sh.out
 if test "$(grep '512/512' test-parallel-sh.out)" != \
 "wrote 512/512 bytes at offset 512
-- 
2.25.1