From 19dbecdceef3f0800a96c25931d71b0b82c3a47a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 18 Mar 2016 15:36:31 +0100 Subject: qemu-io: Use bdrv_parse_cache_mode() in reopen_f() We must forbid changing the WCE flag in bdrv_reopen() in the same patch, as otherwise the behaviour would change so that the flag takes precedence over the explicitly specified option. The correct value of the WCE flag depends on the BlockBackend user (e.g. guest device) and isn't a decision that the QMP client makes, so this change is what we want. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- qemu-io-cmds.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'qemu-io-cmds.c') diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c index 139f7ebcbb..932e367a17 100644 --- a/qemu-io-cmds.c +++ b/qemu-io-cmds.c @@ -2106,6 +2106,7 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv) QDict *opts; int c; int flags = bs->open_flags; + bool writethrough = !blk_enable_write_cache(blk); BlockReopenQueue *brq; Error *local_err = NULL; @@ -2113,7 +2114,7 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv) while ((c = getopt(argc, argv, "c:o:r")) != -1) { switch (c) { case 'c': - if (bdrv_parse_cache_flags(optarg, &flags) < 0) { + if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) < 0) { error_report("Invalid cache option: %s", optarg); return 0; } @@ -2138,14 +2139,25 @@ static int reopen_f(BlockBackend *blk, int argc, char **argv) return qemuio_command_usage(&reopen_cmd); } + if (writethrough != blk_enable_write_cache(blk) && + blk_get_attached_dev(blk)) + { + error_report("Cannot change cache.writeback: Device attached"); + qemu_opts_reset(&reopen_opts); + return 0; + } + qopts = qemu_opts_find(&reopen_opts, NULL); opts = qopts ? qemu_opts_to_qdict(qopts, NULL) : NULL; qemu_opts_reset(&reopen_opts); + flags |= blk_enable_write_cache(blk) ? BDRV_O_CACHE_WB : 0; brq = bdrv_reopen_queue(NULL, bs, opts, flags); bdrv_reopen_multiple(brq, &local_err); if (local_err) { error_report_err(local_err); + } else { + blk_set_enable_write_cache(blk, !writethrough); } return 0; -- cgit 1.4.1