From 7676e2c597000eff3a7233b40cca768b358f9bc9 Mon Sep 17 00:00:00 2001 From: Jeff Cody Date: Mon, 30 Jun 2014 15:14:15 +0200 Subject: block: make 'top' argument to block-commit optional Now that active layer block-commit is supported, the 'top' argument no longer needs to be mandatory. Change it to optional, with the default being the active layer in the device chain. [kwolf: Rebased and resolved conflict in tests/qemu-iotests/040] Reviewed-by: Eric Blake Reviewed-by: Benoit Canet Signed-off-by: Jeff Cody Signed-off-by: Kevin Wolf Signed-off-by: Stefan Hajnoczi --- blockdev.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'blockdev.c') diff --git a/blockdev.c b/blockdev.c index 69b7c2a8c5..79ce52b58b 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1913,7 +1913,8 @@ void qmp_block_stream(const char *device, bool has_base, } void qmp_block_commit(const char *device, - bool has_base, const char *base, const char *top, + bool has_base, const char *base, + bool has_top, const char *top, bool has_speed, int64_t speed, Error **errp) { @@ -1932,6 +1933,11 @@ void qmp_block_commit(const char *device, /* drain all i/o before commits */ bdrv_drain_all(); + /* Important Note: + * libvirt relies on the DeviceNotFound error class in order to probe for + * live commit feature versions; for this to work, we must make sure to + * perform the device lookup before any generic errors that may occur in a + * scenario in which all optional arguments are omitted. */ bs = bdrv_find(device); if (!bs) { error_set(errp, QERR_DEVICE_NOT_FOUND, device); @@ -1945,7 +1951,7 @@ void qmp_block_commit(const char *device, /* default top_bs is the active layer */ top_bs = bs; - if (top) { + if (has_top && top) { if (strcmp(bs->filename, top) != 0) { top_bs = bdrv_find_backing_image(bs, top); } @@ -1967,6 +1973,12 @@ void qmp_block_commit(const char *device, return; } + /* Do not allow attempts to commit an image into itself */ + if (top_bs == base_bs) { + error_setg(errp, "cannot commit an image into itself"); + return; + } + if (top_bs == bs) { commit_active_start(bs, base_bs, speed, on_error, block_job_cb, bs, &local_err); -- cgit v1.2.3-55-g7522