qcow2: Return real error in qcow2_snapshot_goto

Besides fixing the return code, this adds some comments that make clear
how the code works and that it potentially breaks images if we fail in
the wrong place. Actually fixing this is left for the next patch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
1 file changed
tree: 283187088f5bbdc0692bbdde711dcf53dc2d73b1
  1. audio/
  2. block/
  3. bsd-user/
  4. darwin-user/
  5. default-configs/
  6. docs/
  7. fpu/
  8. fsdev/
  9. gdb-xml/
  10. hw/
  11. libcacard/
  12. linux-headers/
  13. linux-user/
  14. net/
  15. pc-bios/
  16. qapi/
  17. qga/
  18. QMP/
  19. roms/
  20. scripts/
  21. slirp/
  22. sysconfigs/
  23. target-alpha/
  24. target-arm/
  25. target-cris/
  26. target-i386/
  27. target-lm32/
  28. target-m68k/
  29. target-microblaze/
  30. target-mips/
  31. target-ppc/
  32. target-s390x/
  33. target-sh4/
  34. target-sparc/
  35. target-unicore32/
  36. target-xtensa/
  37. tcg/
  38. tests/
  39. trace/
  40. ui/
  41. .gitignore
  42. .gitmodules
  43. a.out.h
  44. acl.c
  45. acl.h
  46. aes.c
  47. aes.h
  48. aio.c
  49. alpha-dis.c
  50. alpha.ld
  51. arch_init.c
  52. arch_init.h
  53. arm-dis.c
  54. arm-semi.c
  55. arm.ld
  56. async.c
  57. balloon.c
  58. balloon.h
  59. bitmap.c
  60. bitmap.h
  61. bitops.c
  62. bitops.h
  63. block-migration.c
  64. block-migration.h
  65. block.c
  66. block.h
  67. block_int.h
  68. blockdev.c
  69. blockdev.h
  70. bswap.h
  71. bt-host.c
  72. bt-host.h
  73. bt-vhci.c
  74. buffered_file.c
  75. buffered_file.h
  76. cache-utils.c
  77. cache-utils.h
  78. Changelog
  79. check-qdict.c
  80. check-qfloat.c
  81. check-qint.c
  82. check-qjson.c
  83. check-qlist.c
  84. check-qstring.c
  85. cmd.c
  86. cmd.h
  87. CODING_STYLE
  88. compatfd.c
  89. compatfd.h
  90. compiler.h
  91. config.h
  92. configure
  93. console.c
  94. console.h
  95. COPYING
  96. COPYING.LIB
  97. coroutine-gthread.c
  98. coroutine-ucontext.c
  99. coroutine-win32.c
  100. cpu-all.h
  101. cpu-common.h
  102. cpu-defs.h
  103. cpu-exec.c
  104. cpus.c
  105. cpus.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. dyngen-exec.h
  120. elf.h
  121. envlist.c
  122. envlist.h
  123. error.c
  124. error.h
  125. error_int.h
  126. event_notifier.c
  127. event_notifier.h
  128. exec-all.h
  129. exec-memory.h
  130. exec.c
  131. gdbstub.c
  132. gdbstub.h
  133. gen-icount.h
  134. HACKING
  135. hmp-commands.hx
  136. hmp.c
  137. hmp.h
  138. host-utils.c
  139. host-utils.h
  140. hppa-dis.c
  141. hppa.ld
  142. i386-dis.c
  143. i386.ld
  144. ia64-dis.c
  145. ia64.ld
  146. input.c
  147. int128.h
  148. iohandler.c
  149. ioport-user.c
  150. ioport.c
  151. ioport.h
  152. iorange.h
  153. iov.c
  154. iov.h
  155. json-lexer.c
  156. json-lexer.h
  157. json-parser.c
  158. json-parser.h
  159. json-streamer.c
  160. json-streamer.h
  161. kvm-all.c
  162. kvm-stub.c
  163. kvm.h
  164. libfdt_env.h
  165. LICENSE
  166. linux-aio.c
  167. m68k-dis.c
  168. m68k-semi.c
  169. m68k.ld
  170. main-loop.c
  171. main-loop.h
  172. MAINTAINERS
  173. Makefile
  174. Makefile.dis
  175. Makefile.hw
  176. Makefile.objs
  177. Makefile.target
  178. Makefile.user
  179. memory.c
  180. memory.h
  181. microblaze-dis.c
  182. migration-exec.c
  183. migration-fd.c
  184. migration-tcp.c
  185. migration-unix.c
  186. migration.c
  187. migration.h
  188. mips-dis.c
  189. mips.ld
  190. module.c
  191. module.h
  192. monitor.c
  193. monitor.h
  194. nbd.c
  195. nbd.h
  196. net.c
  197. net.h
  198. notify.c
  199. notify.h
  200. os-posix.c
  201. os-win32.c
  202. osdep.c
  203. osdep.h
  204. oslib-posix.c
  205. oslib-win32.c
  206. path.c
  207. pci-ids.txt
  208. pflib.c
  209. pflib.h
  210. poison.h
  211. posix-aio-compat.c
  212. ppc-dis.c
  213. ppc.ld
  214. ppc64.ld
  215. qapi-schema-guest.json
  216. qapi-schema-test.json
  217. qapi-schema.json
  218. qbool.c
  219. qbool.h
  220. qdict-test-data.txt
  221. qdict.c
  222. qdict.h
  223. qemu-aio.h
  224. qemu-barrier.h
  225. qemu-char.c
  226. qemu-char.h
  227. qemu-common.h
  228. qemu-config.c
  229. qemu-config.h
  230. qemu-coroutine-int.h
  231. qemu-coroutine-lock.c
  232. qemu-coroutine.c
  233. qemu-coroutine.h
  234. qemu-doc.texi
  235. qemu-error.c
  236. qemu-error.h
  237. qemu-ga.c
  238. qemu-img-cmds.hx
  239. qemu-img.c
  240. qemu-img.texi
  241. qemu-io.c
  242. qemu-lock.h
  243. qemu-log.h
  244. qemu-nbd.c
  245. qemu-nbd.texi
  246. qemu-objects.h
  247. qemu-option.c
  248. qemu-option.h
  249. qemu-options.h
  250. qemu-options.hx
  251. qemu-os-posix.h
  252. qemu-os-win32.h
  253. qemu-progress.c
  254. qemu-queue.h
  255. qemu-sockets.c
  256. qemu-tech.texi
  257. qemu-thread-posix.c
  258. qemu-thread-posix.h
  259. qemu-thread-win32.c
  260. qemu-thread-win32.h
  261. qemu-thread.h
  262. qemu-timer-common.c
  263. qemu-timer.c
  264. qemu-timer.h
  265. qemu-tls.h
  266. qemu-tool.c
  267. qemu-x509.h
  268. qemu-xattr.h
  269. qemu.sasl
  270. qemu_socket.h
  271. qerror.c
  272. qerror.h
  273. qfloat.c
  274. qfloat.h
  275. qint.c
  276. qint.h
  277. qjson.c
  278. qjson.h
  279. qlist.c
  280. qlist.h
  281. qmp-commands.hx
  282. qmp.c
  283. qobject.h
  284. qstring.c
  285. qstring.h
  286. range.h
  287. readline.c
  288. readline.h
  289. README
  290. rules.mak
  291. s390-dis.c
  292. s390.ld
  293. savevm.c
  294. sh4-dis.c
  295. softmmu-semi.h
  296. softmmu_defs.h
  297. softmmu_exec.h
  298. softmmu_header.h
  299. softmmu_template.h
  300. sparc-dis.c
  301. sparc.ld
  302. sparc64.ld
  303. spice-qemu-char.c
  304. sysemu.h
  305. targphys.h
  306. tcg-runtime.c
  307. tci-dis.c
  308. tci.c
  309. test-coroutine.c
  310. test-qmp-commands.c
  311. test-visitor.c
  312. thunk.c
  313. thunk.h
  314. TODO
  315. trace-events
  316. translate-all.c
  317. uboot_image.h
  318. usb-bsd.c
  319. usb-linux.c
  320. usb-redir.c
  321. usb-stub.c
  322. user-exec.c
  323. VERSION
  324. version.rc
  325. vgafont.h
  326. vl.c
  327. x86_64.ld
  328. xen-all.c
  329. xen-mapcache.c
  330. xen-mapcache.h
  331. xen-stub.c
  332. xtensa-semi.c