qemu-iotests: fix cleanup of background processes

Commit 934659c switched the iotests to run qemu and qemu-nbd from a bash
subshell, in order to catch segfaults.  Unfortunately, this means the
process PID cannot be captured via '$!'. We stopped killing qemu and
qemu-nbd processes, leaving a lot of orphaned, running qemu processes
after executing iotests.

Since the process is using exec in the subshell, the PID is the
same as the subshell PID.

Track these PIDs for cleanup using pidfiles in the $TEST_DIR. Only
track the qemu PID, however, if requested - not all usage requires
killing the process.

Reported-by: John Snow <jsnow@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-id: 9e4f958b3895b7259b98d845bb46f000ba362869.1446232490.git.jcody@redhat.com
[mreitz@redhat.com: Replaced '! -z "..."' by '-n "..."']
Signed-off-by: Max Reitz <mreitz@redhat.com>
4 files changed
tree: 6e6d7147a600244e9d116957d7636eadf8c8d8ef
  1. audio/
  2. backends/
  3. block/
  4. bsd-user/
  5. contrib/
  6. crypto/
  7. default-configs/
  8. disas/
  9. docs/
  10. fpu/
  11. fsdev/
  12. gdb-xml/
  13. hw/
  14. include/
  15. libdecnumber/
  16. linux-headers/
  17. linux-user/
  18. migration/
  19. net/
  20. pc-bios/
  21. po/
  22. qapi/
  23. qga/
  24. qobject/
  25. qom/
  26. replay/
  27. roms/
  28. scripts/
  29. slirp/
  30. stubs/
  31. target-alpha/
  32. target-arm/
  33. target-cris/
  34. target-i386/
  35. target-lm32/
  36. target-m68k/
  37. target-microblaze/
  38. target-mips/
  39. target-moxie/
  40. target-openrisc/
  41. target-ppc/
  42. target-s390x/
  43. target-sh4/
  44. target-sparc/
  45. target-tilegx/
  46. target-tricore/
  47. target-unicore32/
  48. target-xtensa/
  49. tcg/
  50. tests/
  51. trace/
  52. ui/
  53. util/
  54. .dir-locals.el
  55. .exrc
  56. .gitignore
  57. .gitmodules
  58. .mailmap
  59. .travis.yml
  60. accel.c
  61. aio-posix.c
  62. aio-win32.c
  63. arch_init.c
  64. async.c
  65. balloon.c
  66. block.c
  67. blockdev-nbd.c
  68. blockdev.c
  69. blockjob.c
  70. bootdevice.c
  71. bt-host.c
  72. bt-vhci.c
  73. Changelog
  74. CODING_STYLE
  75. configure
  76. COPYING
  77. COPYING.LIB
  78. cpu-exec-common.c
  79. cpu-exec.c
  80. cpus.c
  81. cputlb.c
  82. device-hotplug.c
  83. device_tree.c
  84. disas.c
  85. dma-helpers.c
  86. dump.c
  87. exec.c
  88. gdbstub.c
  89. HACKING
  90. hmp-commands-info.hx
  91. hmp-commands.hx
  92. hmp.c
  93. hmp.h
  94. iohandler.c
  95. ioport.c
  96. iothread.c
  97. kvm-all.c
  98. kvm-stub.c
  99. LICENSE
  100. main-loop.c
  101. MAINTAINERS
  102. Makefile
  103. Makefile.objs
  104. Makefile.target
  105. memory.c
  106. memory_mapping.c
  107. module-common.c
  108. monitor.c
  109. nbd.c
  110. numa.c
  111. os-posix.c
  112. os-win32.c
  113. page_cache.c
  114. qapi-schema.json
  115. qdev-monitor.c
  116. qdict-test-data.txt
  117. qemu-bridge-helper.c
  118. qemu-char.c
  119. qemu-doc.texi
  120. qemu-ga.texi
  121. qemu-img-cmds.hx
  122. qemu-img.c
  123. qemu-img.texi
  124. qemu-io-cmds.c
  125. qemu-io.c
  126. qemu-log.c
  127. qemu-nbd.c
  128. qemu-nbd.texi
  129. qemu-options-wrapper.h
  130. qemu-options.h
  131. qemu-options.hx
  132. qemu-seccomp.c
  133. qemu-tech.texi
  134. qemu-timer.c
  135. qemu.nsi
  136. qemu.sasl
  137. qjson.c
  138. qmp-commands.hx
  139. qmp.c
  140. qtest.c
  141. README
  142. rules.mak
  143. softmmu_template.h
  144. spice-qemu-char.c
  145. tcg-runtime.c
  146. tci.c
  147. thread-pool.c
  148. thunk.c
  149. tpm.c
  150. trace-events
  151. translate-all.c
  152. translate-all.h
  153. translate-common.c
  154. user-exec.c
  155. VERSION
  156. version.rc
  157. vl.c
  158. xen-common-stub.c
  159. xen-common.c
  160. xen-hvm-stub.c
  161. xen-hvm.c
  162. xen-mapcache.c