qed: refuse unaligned zero writes with a backing file

Zero writes have cluster granularity in QED.  Therefore they can only be
used to zero entire clusters.

If the zero write request leaves sectors untouched, zeroing the entire
cluster would obscure the backing file.  Instead return -ENOTSUP, which
is handled by block.c:bdrv_co_do_write_zeroes() and falls back to a
regular write.

The qemu-iotests 034 test cases covers this scenario.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
1 file changed
tree: a4601e141bf87c772980c1aef6c0fd462dc3fe87
  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. .gitignore
  44. .gitmodules
  45. .mailmap
  46. a.out.h
  47. acl.c
  48. acl.h
  49. aes.c
  50. aes.h
  51. aio.c
  52. alpha-dis.c
  53. alpha.ld
  54. arch_init.c
  55. arch_init.h
  56. arm-dis.c
  57. arm.ld
  58. async.c
  59. balloon.c
  60. balloon.h
  61. bitmap.c
  62. bitmap.h
  63. bitops.c
  64. bitops.h
  65. block-migration.c
  66. block-migration.h
  67. block.c
  68. block.h
  69. block_int.h
  70. blockdev.c
  71. blockdev.h
  72. bswap.h
  73. bt-host.c
  74. bt-host.h
  75. bt-vhci.c
  76. buffered_file.c
  77. buffered_file.h
  78. cache-utils.c
  79. cache-utils.h
  80. Changelog
  81. cmd.c
  82. cmd.h
  83. CODING_STYLE
  84. compatfd.c
  85. compatfd.h
  86. compiler.h
  87. config.h
  88. configure
  89. console.c
  90. console.h
  91. COPYING
  92. COPYING.LIB
  93. coroutine-gthread.c
  94. coroutine-sigaltstack.c
  95. coroutine-ucontext.c
  96. coroutine-win32.c
  97. cpu-all.h
  98. cpu-common.h
  99. cpu-defs.h
  100. cpu-exec.c
  101. cpus.c
  102. cpus.h
  103. cputlb.c
  104. cputlb.h
  105. cris-dis.c
  106. cursor.c
  107. cursor_hidden.xpm
  108. cursor_left_ptr.xpm
  109. cutils.c
  110. def-helper.h
  111. device_tree.c
  112. device_tree.h
  113. dis-asm.h
  114. disas.c
  115. disas.h
  116. dma-helpers.c
  117. dma.h
  118. dump-stub.c
  119. dump.c
  120. dump.h
  121. dyngen-exec.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