cutils: extract buffer_is_zero() from qemu-img.c

The qemu-img.c:is_not_zero() function checks if a buffer contains all
zeroes.  This function will come in handy for zero-detection in the
block layer, so clean it up and move it to cutils.c.

Note that the function now returns true if the buffer is all zeroes.
This avoids the double-negatives (i.e. !is_not_zero()) that the old
function can cause in callers.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
3 files changed
tree: 9b15c86f85e8141f3a20cbf9f52ea21a0719e598
  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. include/
  12. libcacard/
  13. linux-headers/
  14. linux-user/
  15. net/
  16. pc-bios/
  17. qapi/
  18. qga/
  19. QMP/
  20. qom/
  21. roms/
  22. scripts/
  23. slirp/
  24. sysconfigs/
  25. target-alpha/
  26. target-arm/
  27. target-cris/
  28. target-i386/
  29. target-lm32/
  30. target-m68k/
  31. target-microblaze/
  32. target-mips/
  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-semi.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. check-qdict.c
  83. check-qfloat.c
  84. check-qint.c
  85. check-qjson.c
  86. check-qlist.c
  87. check-qstring.c
  88. cmd.c
  89. cmd.h
  90. CODING_STYLE
  91. compatfd.c
  92. compatfd.h
  93. compiler.h
  94. config.h
  95. configure
  96. console.c
  97. console.h
  98. COPYING
  99. COPYING.LIB
  100. coroutine-gthread.c
  101. coroutine-ucontext.c
  102. coroutine-win32.c
  103. cpu-all.h
  104. cpu-common.h
  105. cpu-defs.h
  106. cpu-exec.c
  107. cpus.c
  108. cpus.h
  109. cris-dis.c
  110. cursor.c
  111. cursor_hidden.xpm
  112. cursor_left_ptr.xpm
  113. cutils.c
  114. def-helper.h
  115. device_tree.c
  116. device_tree.h
  117. dis-asm.h
  118. disas.c
  119. disas.h
  120. dma-helpers.c
  121. dma.h
  122. dyngen-exec.h
  123. elf.h
  124. envlist.c
  125. envlist.h
  126. error.c
  127. error.h
  128. error_int.h
  129. event_notifier.c
  130. event_notifier.h
  131. exec-all.h
  132. exec-memory.h
  133. exec-obsolete.h
  134. exec.c
  135. gdbstub.c
  136. gdbstub.h
  137. gen-icount.h
  138. HACKING
  139. hmp-commands.hx
  140. hmp.c
  141. hmp.h
  142. host-utils.c
  143. host-utils.h
  144. hppa-dis.c
  145. hppa.ld
  146. i386-dis.c
  147. i386.ld
  148. ia64-dis.c
  149. ia64.ld
  150. input.c
  151. int128.h
  152. iohandler.c
  153. ioport-user.c
  154. ioport.c
  155. ioport.h
  156. iorange.h
  157. iov.c
  158. iov.h
  159. json-lexer.c
  160. json-lexer.h
  161. json-parser.c
  162. json-parser.h
  163. json-streamer.c
  164. json-streamer.h
  165. kvm-all.c
  166. kvm-stub.c
  167. kvm.h
  168. libfdt_env.h
  169. LICENSE
  170. linux-aio.c
  171. m68k-dis.c
  172. m68k-semi.c
  173. m68k.ld
  174. main-loop.c
  175. main-loop.h
  176. MAINTAINERS
  177. Makefile
  178. Makefile.dis
  179. Makefile.hw
  180. Makefile.objs
  181. Makefile.target
  182. Makefile.user
  183. memory.c
  184. memory.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. path.c
  211. pci-ids.txt
  212. pflib.c
  213. pflib.h
  214. poison.h
  215. posix-aio-compat.c
  216. ppc-dis.c
  217. ppc.ld
  218. ppc64.ld
  219. qapi-schema-guest.json
  220. qapi-schema-test.json
  221. qapi-schema.json
  222. qbool.c
  223. qbool.h
  224. qdict-test-data.txt
  225. qdict.c
  226. qdict.h
  227. qemu-aio.h
  228. qemu-barrier.h
  229. qemu-bridge-helper.c
  230. qemu-char.c
  231. qemu-char.h
  232. qemu-common.h
  233. qemu-config.c
  234. qemu-config.h
  235. qemu-coroutine-int.h
  236. qemu-coroutine-io.c
  237. qemu-coroutine-lock.c
  238. qemu-coroutine-sleep.c
  239. qemu-coroutine.c
  240. qemu-coroutine.h
  241. qemu-doc.texi
  242. qemu-error.c
  243. qemu-error.h
  244. qemu-file.h
  245. qemu-ga.c
  246. qemu-img-cmds.hx
  247. qemu-img.c
  248. qemu-img.texi
  249. qemu-io.c
  250. qemu-lock.h
  251. qemu-log.h
  252. qemu-nbd.c
  253. qemu-nbd.texi
  254. qemu-objects.h
  255. qemu-option.c
  256. qemu-option.h
  257. qemu-options-wrapper.h
  258. qemu-options.h
  259. qemu-options.hx
  260. qemu-os-posix.h
  261. qemu-os-win32.h
  262. qemu-progress.c
  263. qemu-queue.h
  264. qemu-sockets.c
  265. qemu-tech.texi
  266. qemu-thread-posix.c
  267. qemu-thread-posix.h
  268. qemu-thread-win32.c
  269. qemu-thread-win32.h
  270. qemu-thread.h
  271. qemu-timer-common.c
  272. qemu-timer.c
  273. qemu-timer.h
  274. qemu-tls.h
  275. qemu-tool.c
  276. qemu-x509.h
  277. qemu-xattr.h
  278. qemu.sasl
  279. qemu_socket.h
  280. qerror.c
  281. qerror.h
  282. qfloat.c
  283. qfloat.h
  284. qint.c
  285. qint.h
  286. qjson.c
  287. qjson.h
  288. qlist.c
  289. qlist.h
  290. qmp-commands.hx
  291. qmp.c
  292. qobject.h
  293. qstring.c
  294. qstring.h
  295. range.h
  296. readline.c
  297. readline.h
  298. README
  299. rules.mak
  300. s390-dis.c
  301. s390.ld
  302. savevm.c
  303. sh4-dis.c
  304. softmmu-semi.h
  305. softmmu_defs.h
  306. softmmu_exec.h
  307. softmmu_header.h
  308. softmmu_template.h
  309. sparc-dis.c
  310. sparc.ld
  311. sparc64.ld
  312. spice-qemu-char.c
  313. sysemu.h
  314. targphys.h
  315. tcg-runtime.c
  316. tci-dis.c
  317. tci.c
  318. test-coroutine.c
  319. test-qmp-commands.c
  320. test-qmp-input-visitor.c
  321. test-qmp-output-visitor.c
  322. thunk.c
  323. thunk.h
  324. TODO
  325. trace-events
  326. translate-all.c
  327. uboot_image.h
  328. usb-bsd.c
  329. usb-linux.c
  330. usb-redir.c
  331. usb-stub.c
  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
  343. xtensa-semi.c