[libvirt] [PATCH v5 7/7] qemu: Add ability to abort existing console while creating new one

This patch fixes console corruption, that happens if two concurrent sessions are opened for a single console on a domain. Result of this corruption was that each of the console streams recieved just a part of the data written to the pipe so every console rendered unusable. New helper function for safe console handling is used to establish the console stream connection. This function ensures that no other libvirt client is using the console (with the ability to disconnect consoles of libvirt clients) and that no UUCP style lockfile is placed on the PTY device. * src/qemu/qemu_domain.h - add data structure to domain's private data dealing with console connections * src/qemu/qemu_domain.c: - allocate/free domain's console data structure * src/qemu/qemu_driver.c - use the new helper function for console handling --- No changes. src/qemu/qemu_domain.c | 5 +++++ src/qemu/qemu_domain.h | 3 +++ src/qemu/qemu_driver.c | 21 ++++++++++++++++----- 3 files changed, 24 insertions(+), 5 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 01e5580..2fed91e 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -192,6 +192,9 @@ static void *qemuDomainObjPrivateAlloc(void) if (qemuDomainObjInitJob(priv) < 0) goto error; + if (!(priv->cons = virConsoleAlloc())) + goto error; + priv->migMaxBandwidth = QEMU_DOMAIN_DEFAULT_MIG_BANDWIDTH_MAX; return priv; @@ -214,6 +217,8 @@ static void qemuDomainObjPrivateFree(void *data) VIR_FREE(priv->lockState); VIR_FREE(priv->origname); + virConsoleFree(priv->cons); + /* This should never be non-NULL if we get here, but just in case... */ if (priv->mon) { VIR_ERROR(_("Unexpected QEMU monitor still active during domain deletion")); diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index 222d80e..1333d8c 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -30,6 +30,7 @@ # include "qemu_agent.h" # include "qemu_conf.h" # include "bitmap.h" +# include "virconsole.h" # define QEMU_EXPECTED_VIRT_TYPES \ ((1 << VIR_DOMAIN_VIRT_QEMU) | \ @@ -127,6 +128,8 @@ struct _qemuDomainObjPrivate { unsigned long migMaxBandwidth; char *origname; + + virConsolesPtr cons; }; struct qemuDomainWatchdogEvent diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 717bdf1..1d869fb 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -11243,8 +11243,10 @@ qemuDomainOpenConsole(virDomainPtr dom, int ret = -1; int i; virDomainChrDefPtr chr = NULL; + qemuDomainObjPrivatePtr priv; - virCheckFlags(0, -1); + virCheckFlags(VIR_DOMAIN_CONSOLE_SAFE | + VIR_DOMAIN_CONSOLE_FORCE, -1); qemuDriverLock(driver); virUUIDFormat(dom->uuid, uuidstr); @@ -11261,6 +11263,8 @@ qemuDomainOpenConsole(virDomainPtr dom, goto cleanup; } + priv = vm->privateData; + if (dev_name) { for (i = 0 ; !chr && i < vm->def->nconsoles ; i++) { if (vm->def->consoles[i]->info.alias && @@ -11296,11 +11300,18 @@ qemuDomainOpenConsole(virDomainPtr dom, goto cleanup; } - if (virFDStreamOpenFile(st, chr->source.data.file.path, - 0, 0, O_RDWR) < 0) - goto cleanup; + /* handle mutually exclusive access to console devices */ + ret = virConsoleOpen(priv->cons, + chr->source.data.file.path, + st, + (flags & VIR_DOMAIN_CONSOLE_FORCE) != 0); + + if (ret == 1) { + qemuReportError(VIR_ERR_OPERATION_FAILED, + _("Active console session exists for this domain")); + ret = -1; + } - ret = 0; cleanup: if (vm) virDomainObjUnlock(vm); -- 1.7.3.4