nbd: do not leak nbd_trip coroutines when a connection is torn down

Because nbd_client_close removes the I/O handlers for the client
socket, there is no way that any suspended coroutines are restarted.
This will be a problem with the QEMU embedded NBD server, because
we will have a QMP command to forcibly close all connections with
the clients.

Instead, we can exploit the reference counting of NBDClients; shutdown the
client socket, which will make it readable and writeable.  Also call the
close callback, which will release the user's reference.  The coroutines
then will fail and exit cleanly, and release all remaining references,
until the last refcount finally triggers the closure of the client.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 files changed
tree: 3ddaf5829ccd5d60a14345cf0d5d6c4981bf6d2d
  1. audio/
  2. block/
  3. bsd-user/
  4. default-configs/
  5. docs/
  6. fpu/
  7. fsdev/
  8. gdb-xml/
  9. hw/
  10. include/
  11. libcacard/
  12. linux-headers/
  13. linux-user/
  14. net/
  15. pc-bios/
  16. qapi/
  17. qga/
  18. QMP/
  19. qom/
  20. roms/
  21. scripts/
  22. slirp/
  23. sysconfigs/
  24. target-alpha/
  25. target-arm/
  26. target-cris/
  27. target-i386/
  28. target-lm32/
  29. target-m68k/
  30. target-microblaze/
  31. target-mips/
  32. target-openrisc/
  33. target-ppc/
  34. target-s390x/
  35. target-sh4/
  36. target-sparc/
  37. target-unicore32/
  38. target-xtensa/
  39. tcg/
  40. tests/
  41. trace/
  42. ui/
  43. .exrc
  44. .gitignore
  45. .gitmodules
  46. .mailmap
  47. a.out.h
  48. acl.c
  49. acl.h
  50. aes.c
  51. aes.h
  52. aio.c
  53. alpha-dis.c
  54. alpha.ld
  55. arch_init.c
  56. arch_init.h
  57. arm-dis.c
  58. arm.ld
  59. async.c
  60. balloon.c
  61. balloon.h
  62. bitmap.c
  63. bitmap.h
  64. bitops.c
  65. bitops.h
  66. block-migration.c
  67. block-migration.h
  68. block.c
  69. block.h
  70. block_int.h
  71. blockdev.c
  72. blockdev.h
  73. bswap.h
  74. bt-host.c
  75. bt-host.h
  76. bt-vhci.c
  77. buffered_file.c
  78. buffered_file.h
  79. cache-utils.c
  80. cache-utils.h
  81. Changelog
  82. cmd.c
  83. cmd.h
  84. CODING_STYLE
  85. compatfd.c
  86. compatfd.h
  87. compiler.h
  88. config.h
  89. configure
  90. console.c
  91. console.h
  92. COPYING
  93. COPYING.LIB
  94. coroutine-gthread.c
  95. coroutine-sigaltstack.c
  96. coroutine-ucontext.c
  97. coroutine-win32.c
  98. cpu-all.h
  99. cpu-common.h
  100. cpu-defs.h
  101. cpu-exec.c
  102. cpus.c
  103. cpus.h
  104. cputlb.c
  105. cputlb.h
  106. cris-dis.c
  107. cursor.c
  108. cursor_hidden.xpm
  109. cursor_left_ptr.xpm
  110. cutils.c
  111. def-helper.h
  112. device_tree.c
  113. device_tree.h
  114. dis-asm.h
  115. disas.c
  116. disas.h
  117. dma-helpers.c
  118. dma.h
  119. dump-stub.c
  120. dump.c
  121. dump.h
  122. elf.h
  123. envlist.c
  124. envlist.h
  125. error.c
  126. error.h
  127. event_notifier.c
  128. event_notifier.h
  129. exec-all.h
  130. exec-memory.h
  131. exec-obsolete.h
  132. exec.c
  133. gdbstub.c
  134. gdbstub.h
  135. gen-icount.h
  136. HACKING
  137. hmp-commands.hx
  138. hmp.c
  139. hmp.h
  140. host-utils.c
  141. host-utils.h
  142. hppa-dis.c
  143. hppa.ld
  144. i386-dis.c
  145. i386.ld
  146. ia64-dis.c
  147. ia64.ld
  148. input.c
  149. int128.h
  150. iohandler.c
  151. ioport.c
  152. ioport.h
  153. iorange.h
  154. iov.c
  155. iov.h
  156. json-lexer.c
  157. json-lexer.h
  158. json-parser.c
  159. json-parser.h
  160. json-streamer.c
  161. json-streamer.h
  162. kvm-all.c
  163. kvm-stub.c
  164. kvm.h
  165. libfdt_env.h
  166. LICENSE
  167. linux-aio.c
  168. lm32-dis.c
  169. m68k-dis.c
  170. m68k.ld
  171. main-loop.c
  172. main-loop.h
  173. MAINTAINERS
  174. Makefile
  175. Makefile.dis
  176. Makefile.hw
  177. Makefile.objs
  178. Makefile.target
  179. Makefile.user
  180. memory.c
  181. memory.h
  182. memory_mapping-stub.c
  183. memory_mapping.c
  184. memory_mapping.h
  185. microblaze-dis.c
  186. migration-exec.c
  187. migration-fd.c
  188. migration-tcp.c
  189. migration-unix.c
  190. migration.c
  191. migration.h
  192. mips-dis.c
  193. mips.ld
  194. module.c
  195. module.h
  196. monitor.c
  197. monitor.h
  198. nbd.c
  199. nbd.h
  200. net.c
  201. net.h
  202. notify.c
  203. notify.h
  204. os-posix.c
  205. os-win32.c
  206. osdep.c
  207. osdep.h
  208. oslib-posix.c
  209. oslib-win32.c
  210. page_cache.c
  211. path.c
  212. pci-ids.txt
  213. pflib.c
  214. pflib.h
  215. poison.h
  216. posix-aio-compat.c
  217. ppc-dis.c
  218. ppc.ld
  219. ppc64.ld
  220. qapi-schema-guest.json
  221. qapi-schema-test.json
  222. qapi-schema.json
  223. qbool.c
  224. qbool.h
  225. qdict-test-data.txt
  226. qdict.c
  227. qdict.h
  228. qemu-aio.h
  229. qemu-barrier.h
  230. qemu-bridge-helper.c
  231. qemu-char.c
  232. qemu-char.h
  233. qemu-common.h
  234. qemu-config.c
  235. qemu-config.h
  236. qemu-coroutine-int.h
  237. qemu-coroutine-io.c
  238. qemu-coroutine-lock.c
  239. qemu-coroutine-sleep.c
  240. qemu-coroutine.c
  241. qemu-coroutine.h
  242. qemu-doc.texi
  243. qemu-error.c
  244. qemu-error.h
  245. qemu-file.h
  246. qemu-ga.c
  247. qemu-img-cmds.hx
  248. qemu-img.c
  249. qemu-img.texi
  250. qemu-io.c
  251. qemu-lock.h
  252. qemu-log.c
  253. qemu-log.h
  254. qemu-nbd.c
  255. qemu-nbd.texi
  256. qemu-objects.h
  257. qemu-option-internal.h
  258. qemu-option.c
  259. qemu-option.h
  260. qemu-options-wrapper.h
  261. qemu-options.h
  262. qemu-options.hx
  263. qemu-os-posix.h
  264. qemu-os-win32.h
  265. qemu-progress.c
  266. qemu-queue.h
  267. qemu-seccomp.c
  268. qemu-seccomp.h
  269. qemu-sockets.c
  270. qemu-tech.texi
  271. qemu-thread-posix.c
  272. qemu-thread-posix.h
  273. qemu-thread-win32.c
  274. qemu-thread-win32.h
  275. qemu-thread.h
  276. qemu-timer-common.c
  277. qemu-timer.c
  278. qemu-timer.h
  279. qemu-tls.h
  280. qemu-tool.c
  281. qemu-user.c
  282. qemu-x509.h
  283. qemu-xattr.h
  284. qemu.sasl
  285. qemu_socket.h
  286. qerror.c
  287. qerror.h
  288. qfloat.c
  289. qfloat.h
  290. qint.c
  291. qint.h
  292. qjson.c
  293. qjson.h
  294. qlist.c
  295. qlist.h
  296. qmp-commands.hx
  297. qmp.c
  298. qobject.h
  299. qstring.c
  300. qstring.h
  301. qtest.c
  302. qtest.h
  303. range.h
  304. readline.c
  305. readline.h
  306. README
  307. rules.mak
  308. s390-dis.c
  309. s390.ld
  310. savevm.c
  311. sh4-dis.c
  312. softmmu-semi.h
  313. softmmu_defs.h
  314. softmmu_exec.h
  315. softmmu_header.h
  316. softmmu_template.h
  317. sparc-dis.c
  318. sparc.ld
  319. sparc64.ld
  320. spice-qemu-char.c
  321. sysemu.h
  322. targphys.h
  323. tcg-runtime.c
  324. tci-dis.c
  325. tci.c
  326. thunk.c
  327. thunk.h
  328. TODO
  329. trace-events
  330. translate-all.c
  331. uboot_image.h
  332. user-exec.c
  333. VERSION
  334. version.rc
  335. vgafont.h
  336. vl.c
  337. vmstate.h
  338. x86_64.ld
  339. xen-all.c
  340. xen-mapcache.c
  341. xen-mapcache.h
  342. xen-stub.c