From 02d2bd7d91c200d1ea1a5b3f78c8b41720cea832 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 29 Aug 2014 13:27:18 -0600 Subject: [PATCH] blockjob: shuffle block rebase code The existing virDomainBlockRebase code rejected the combination of _RELATIVE and _COPY flags, but only by accident. It makes sense to add support for the combination someday, at least for the case of _SHALLOW and not _REUSE_EXT; but to implement it, libvirt would have to pre-create the file with a relative backing name, and I'm not ready to code that in yet. Meanwhile, the code to forward on to the block copy code is getting longer, and reorganizing the function to have the block pull done early makes it easier to add even more block copy prep code. This patch should have no semantic difference other than the quality of the error message on the unsupported flag combination. Pre-patch: error: unsupported flags (0x10) in function qemuDomainBlockCopy Post-patch: error: argument unsupported: Relative backing during copy not supported yet * src/qemu/qemu_driver.c (qemuDomainBlockRebase): Reorder code, and improve error message of relative copy. Signed-off-by: Eric Blake --- src/qemu/qemu_driver.c | 43 +++++++++++++++++++++++++++++------------- 1 file changed, 30 insertions(+), 13 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 5121f855bb..94d48fba14 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -15467,6 +15467,8 @@ qemuDomainBlockRebase(virDomainPtr dom, const char *path, const char *base, unsigned long bandwidth, unsigned int flags) { virDomainObjPtr vm; + const char *format = NULL; + int ret = -1; virCheckFlags(VIR_DOMAIN_BLOCK_REBASE_SHALLOW | VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT | @@ -15477,22 +15479,37 @@ qemuDomainBlockRebase(virDomainPtr dom, const char *path, const char *base, if (!(vm = qemuDomObjFromDomain(dom))) return -1; - if (virDomainBlockRebaseEnsureACL(dom->conn, vm->def) < 0) { - virObjectUnlock(vm); - return -1; - } + if (virDomainBlockRebaseEnsureACL(dom->conn, vm->def) < 0) + goto cleanup; + + /* For normal rebase (enhanced blockpull), the common code handles + * everything, including vm cleanup. */ + if (!(flags & VIR_DOMAIN_BLOCK_REBASE_COPY)) + return qemuDomainBlockJobImpl(vm, dom->conn, path, base, bandwidth, + NULL, BLOCK_JOB_PULL, flags); + + /* If we got here, we are doing a block copy rebase. */ + if (flags & VIR_DOMAIN_BLOCK_REBASE_COPY_RAW) + format = "raw"; - if (flags & VIR_DOMAIN_BLOCK_REBASE_COPY) { - const char *format = NULL; - if (flags & VIR_DOMAIN_BLOCK_REBASE_COPY_RAW) - format = "raw"; - flags &= ~(VIR_DOMAIN_BLOCK_REBASE_COPY | - VIR_DOMAIN_BLOCK_REBASE_COPY_RAW); - return qemuDomainBlockCopy(vm, dom->conn, path, base, format, bandwidth, flags); + /* XXX: If we are doing a shallow copy but not reusing an external + * file, we should attempt to pre-create the destination with a + * relative backing chain instead of qemu's default of absolute */ + if (flags & VIR_DOMAIN_BLOCK_REBASE_RELATIVE) { + virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s", + _("Relative backing during copy not supported yet")); + goto cleanup; } - return qemuDomainBlockJobImpl(vm, dom->conn, path, base, bandwidth, NULL, - BLOCK_JOB_PULL, flags); + flags &= (VIR_DOMAIN_BLOCK_REBASE_SHALLOW | + VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT); + ret = qemuDomainBlockCopy(vm, dom->conn, path, base, format, + bandwidth, flags); + vm = NULL; + cleanup: + if (vm) + virObjectUnlock(vm); + return ret; } static int -- 2.39.5