block: avoid creating too large iovecs in multiwrite_merge

If we go over the maximum number of iovecs support by syscall we get
back EINVAL from the kernel which translate to I/O errors for the guest.

Add a MAX_IOV defintion for platforms that don't have it.  For now we use
the same 1024 define that's used on Linux and various other platforms,
but until the windows block backend implements some kind of vectored I/O
it doesn't matter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2 files changed
tree: e31318d9be44e06a7ae9cda19369236fdbe2bcfc
  1. audio/
  2. block/
  3. bsd-user/
  4. darwin-user/
  5. default-configs/
  6. docs/
  7. fpu/
  8. gdb-xml/
  9. hw/
  10. linux-user/
  11. net/
  12. pc-bios/
  13. QMP/
  14. roms/
  15. slirp/
  16. target-alpha/
  17. target-arm/
  18. target-cris/
  19. target-i386/
  20. target-m68k/
  21. target-microblaze/
  22. target-mips/
  23. target-ppc/
  24. target-s390x/
  25. target-sh4/
  26. target-sparc/
  27. tcg/
  28. tests/
  29. .gitignore
  30. .gitmodules
  31. a.out.h
  32. acl.c
  33. acl.h
  34. aes.c
  35. aes.h
  36. aio.c
  37. alpha-dis.c
  38. alpha.ld
  39. arm-dis.c
  40. arm-semi.c
  41. arm.ld
  42. async.c
  43. balloon.h
  44. block-migration.c
  45. block-migration.h
  46. block.c
  47. block.h
  48. block_int.h
  49. bswap.h
  50. bt-host.c
  51. bt-host.h
  52. bt-vhci.c
  53. buffered_file.c
  54. buffered_file.h
  55. cache-utils.c
  56. cache-utils.h
  57. Changelog
  58. check-qdict.c
  59. check-qfloat.c
  60. check-qint.c
  61. check-qjson.c
  62. check-qlist.c
  63. check-qstring.c
  64. cmd.c
  65. cmd.h
  66. cocoa.m
  67. CODING_STYLE
  68. config.h
  69. configure
  70. console.c
  71. console.h
  72. COPYING
  73. COPYING.LIB
  74. cpu-all.h
  75. cpu-common.h
  76. cpu-defs.h
  77. cpu-exec.c
  78. create_config
  79. cris-dis.c
  80. curses.c
  81. curses_keys.h
  82. cutils.c
  83. d3des.c
  84. d3des.h
  85. def-helper.h
  86. device_tree.c
  87. device_tree.h
  88. dis-asm.h
  89. disas.c
  90. disas.h
  91. dma-helpers.c
  92. dma.h
  93. dyngen-exec.h
  94. elf.h
  95. envlist.c
  96. envlist.h
  97. exec-all.h
  98. exec.c
  99. feature_to_c.sh
  100. gdbstub.c
  101. gdbstub.h
  102. gen-icount.h
  103. host-utils.c
  104. host-utils.h
  105. hostregs_helper.h
  106. hpet.h
  107. hppa-dis.c
  108. hppa.ld
  109. hxtool
  110. i386-dis.c
  111. i386.ld
  112. ia64.ld
  113. input.c
  114. ioport-user.c
  115. ioport.c
  116. ioport.h
  117. json-lexer.c
  118. json-lexer.h
  119. json-parser.c
  120. json-parser.h
  121. json-streamer.c
  122. json-streamer.h
  123. keymaps.c
  124. keymaps.h
  125. kvm-all.c
  126. kvm.h
  127. libfdt_env.h
  128. LICENSE
  129. linux-aio.c
  130. m68k-dis.c
  131. m68k-semi.c
  132. m68k.ld
  133. MAINTAINERS
  134. Makefile
  135. Makefile.hw
  136. Makefile.objs
  137. Makefile.target
  138. Makefile.user
  139. microblaze-dis.c
  140. migration-exec.c
  141. migration-fd.c
  142. migration-tcp.c
  143. migration-unix.c
  144. migration.c
  145. migration.h
  146. mips-dis.c
  147. mips.ld
  148. module.c
  149. module.h
  150. monitor.c
  151. monitor.h
  152. nbd.c
  153. nbd.h
  154. net-checksum.c
  155. net.c
  156. net.h
  157. osdep.c
  158. osdep.h
  159. path.c
  160. pci-ids.txt
  161. posix-aio-compat.c
  162. ppc-dis.c
  163. ppc.ld
  164. ppc64.ld
  165. qbool.c
  166. qbool.h
  167. qdict-test-data.txt
  168. qdict.c
  169. qdict.h
  170. qemu-aio.h
  171. qemu-binfmt-conf.sh
  172. qemu-char.c
  173. qemu-char.h
  174. qemu-common.h
  175. qemu-config.c
  176. qemu-config.h
  177. qemu-doc.texi
  178. qemu-img-cmds.hx
  179. qemu-img.c
  180. qemu-img.texi
  181. qemu-io.c
  182. qemu-lock.h
  183. qemu-log.h
  184. qemu-malloc.c
  185. qemu-monitor.hx
  186. qemu-nbd.c
  187. qemu-nbd.texi
  188. qemu-objects.h
  189. qemu-option.c
  190. qemu-option.h
  191. qemu-options.hx
  192. qemu-queue.h
  193. qemu-sockets.c
  194. qemu-tech.texi
  195. qemu-thread.c
  196. qemu-thread.h
  197. qemu-timer.h
  198. qemu-tool.c
  199. qemu.sasl
  200. qemu_socket.h
  201. qerror.c
  202. qerror.h
  203. qfloat.c
  204. qfloat.h
  205. qint.c
  206. qint.h
  207. qjson.c
  208. qjson.h
  209. qlist.c
  210. qlist.h
  211. qobject.h
  212. qstring.c
  213. qstring.h
  214. readline.c
  215. readline.h
  216. README
  217. rules.mak
  218. s390-dis.c
  219. s390.ld
  220. savevm.c
  221. sdl.c
  222. sdl_keysym.h
  223. sdl_zoom.c
  224. sdl_zoom.h
  225. sdl_zoom_template.h
  226. sh4-dis.c
  227. softmmu-semi.h
  228. softmmu_defs.h
  229. softmmu_exec.h
  230. softmmu_header.h
  231. softmmu_template.h
  232. sparc-dis.c
  233. sparc.ld
  234. sparc64.ld
  235. sysemu.h
  236. targphys.h
  237. tcg-runtime.c
  238. texi2pod.pl
  239. thunk.c
  240. thunk.h
  241. TODO
  242. translate-all.c
  243. uboot_image.h
  244. usb-bsd.c
  245. usb-linux.c
  246. usb-stub.c
  247. VERSION
  248. vgafont.h
  249. vl.c
  250. vnc-auth-sasl.c
  251. vnc-auth-sasl.h
  252. vnc-auth-vencrypt.c
  253. vnc-auth-vencrypt.h
  254. vnc-tls.c
  255. vnc-tls.h
  256. vnc.c
  257. vnc.h
  258. vnc_keysym.h
  259. vnchextile.h
  260. x86_64.ld
  261. x_keymap.c
  262. x_keymap.h