Re: [libvirt] [PATCH 1/2] tools: console: cleanup console on errors in main thread

We only check now for virObjectWait failures in virshRunConsole but we'd better check and for other failures too. Anyway if failure happened we need to shutdown console to stop delivering events from event loop thread or we are in trouble as console is freed on virshRunConsole exit. And we need to add refcounter to console object because event can be delivered after we remove fd handle/stream callback. Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy(a)virtuozzo.com&gt; --- tools/virsh-console.c | 161 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 119 insertions(+), 42 deletions(-)

diff --git a/tools/virsh-console.c b/tools/virsh-console.c index 045a636..c0c3f90 100644 --- a/tools/virsh-console.c +++ b/tools/virsh-console.c @@ -60,9 +60,10 @@ struct virConsoleBuffer { typedef struct virConsole virConsole; typedef virConsole *virConsolePtr; struct virConsole { + virObjectLockable parent; + virStreamPtr st; bool quit; - virMutex lock; virCond cond; int stdinWatch; @@ -74,6 +75,19 @@ struct virConsole { char escapeChar; }; +static virClassPtr virConsoleClass; +static void virConsoleDispose(void *obj); + +static int +virConsoleOnceInit(void) +{ + if (!VIR_CLASS_NEW(virConsole, virClassForObjectLockable())) + return -1; + + return 0; +} + +VIR_ONCE_GLOBAL_INIT(virConsole); static void virConsoleHandleSignal(int sig ATTRIBUTE_UNUSED) @@ -104,16 +118,14 @@ virConsoleShutdown(virConsolePtr con) static void -virConsoleFree(virConsolePtr con) +virConsoleDispose(void *obj) { - if (!con) - return; + virConsolePtr con = obj; if (con->st) virStreamFree(con->st); - virMutexDestroy(&con->lock); + virCondDestroy(&con->cond); - VIR_FREE(con); } @@ -123,6 +135,12 @@ virConsoleEventOnStream(virStreamPtr st, { virConsolePtr con = opaque; + virObjectLock(con); + + /* we got late event after console shutdowned */

+ if (!con->st) + goto cleanup; + if (events & VIR_STREAM_EVENT_READABLE) { size_t avail = con->streamToTerminal.length - con->streamToTerminal.offset; @@ -132,7 +150,7 @@ virConsoleEventOnStream(virStreamPtr st, if (VIR_REALLOC_N(con->streamToTerminal.data, con->streamToTerminal.length + 1024) < 0) { virConsoleShutdown(con); - return; + goto cleanup; } con->streamToTerminal.length += 1024; avail += 1024; @@ -143,10 +161,10 @@ virConsoleEventOnStream(virStreamPtr st, con->streamToTerminal.offset, avail); if (got == -2) - return; /* blocking */ + goto cleanup; /* blocking */ if (got <= 0) { virConsoleShutdown(con); - return; + goto cleanup; } con->streamToTerminal.offset += got; if (con->streamToTerminal.offset) @@ -162,10 +180,10 @@ virConsoleEventOnStream(virStreamPtr st, con->terminalToStream.data, con->terminalToStream.offset); if (done == -2) - return; /* blocking */ + goto cleanup; /* blocking */ if (done < 0) { virConsoleShutdown(con); - return; + goto cleanup; } memmove(con->terminalToStream.data, con->terminalToStream.data + done, @@ -187,6 +205,9 @@ virConsoleEventOnStream(virStreamPtr st, events & VIR_STREAM_EVENT_HANGUP) { virConsoleShutdown(con); } + + cleanup: + virObjectUnlock(con); } @@ -198,6 +219,12 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, { virConsolePtr con = opaque; + virObjectLock(con); + + /* we got late event after console shutdowned */ + if (!con->st) + goto cleanup; + if (events & VIR_EVENT_HANDLE_READABLE) { size_t avail = con->terminalToStream.length - con->terminalToStream.offset; @@ -207,7 +234,7 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, if (VIR_REALLOC_N(con->terminalToStream.data, con->terminalToStream.length + 1024) < 0) { virConsoleShutdown(con); - return; + goto cleanup; } con->terminalToStream.length += 1024; avail += 1024; @@ -220,15 +247,15 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, if (got < 0) { if (errno != EAGAIN) virConsoleShutdown(con); - return; + goto cleanup; } if (got == 0) { virConsoleShutdown(con); - return; + goto cleanup; } if (con->terminalToStream.data[con->terminalToStream.offset] == con->escapeChar) { virConsoleShutdown(con); - return; + goto cleanup; } con->terminalToStream.offset += got; @@ -242,6 +269,9 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, events & VIR_EVENT_HANDLE_HANGUP) { virConsoleShutdown(con); } + + cleanup: + virObjectUnlock(con); } @@ -253,6 +283,12 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, { virConsolePtr con = opaque; + virObjectLock(con); + + /* we got late event after console shutdowned */ + if (!con->st) + goto cleanup; + if (events & VIR_EVENT_HANDLE_WRITABLE && con->streamToTerminal.offset) { ssize_t done; @@ -263,7 +299,7 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, if (done < 0) { if (errno != EAGAIN) virConsoleShutdown(con); - return; + goto cleanup; } memmove(con->streamToTerminal.data, con->streamToTerminal.data + done, @@ -285,6 +321,38 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, events & VIR_EVENT_HANDLE_HANGUP) { virConsoleShutdown(con); } + + cleanup: + virObjectUnlock(con); +} + + +static virConsolePtr +virConsoleNew(void) +{ + virConsolePtr con; + + if (virConsoleInitialize() < 0) + return NULL; + + if (!(con = virObjectNew(virConsoleClass))) + return NULL; + + if (virCondInit(&con->cond) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("cannot initialize console condition")); + + goto error; + } + + con->stdinWatch = -1; + con->stdoutWatch = -1; + + return con; + + error: + virObjectUnref(con); + return NULL; } @@ -324,6 +392,11 @@ virshRunConsole(vshControl *ctl, if (vshTTYMakeRaw(ctl, true) < 0) goto resettty; + if (!(con = virConsoleNew())) + goto resettty; + + virObjectLock(con); + /* Trap all common signals so that we can safely restore the original * terminal settings on STDIN before the process exits - people don't like * being left with a messed up terminal ! */ @@ -333,9 +406,6 @@ virshRunConsole(vshControl *ctl, sigaction(SIGHUP, &sighandler, &old_sighup); sigaction(SIGPIPE, &sighandler, &old_sigpipe); - if (VIR_ALLOC(con) < 0) - goto cleanup; - con->escapeChar = virshGetEscapeChar(priv->escapeChar); con->st = virStreamNew(virDomainGetConnect(dom), VIR_STREAM_NONBLOCK); @@ -345,42 +415,49 @@ virshRunConsole(vshControl *ctl, if (virDomainOpenConsole(dom, dev_name, con->st, flags) < 0) goto cleanup; - if (virCondInit(&con->cond) < 0 || virMutexInit(&con->lock) < 0) + virObjectRef(con); + if ((con->stdinWatch = virEventAddHandle(STDIN_FILENO, + VIR_EVENT_HANDLE_READABLE, + virConsoleEventOnStdin, + con, + virObjectFreeCallback)) < 0) { + virObjectUnref(con); goto cleanup; + }

- virMutexLock(&con->lock); - - con->stdinWatch = virEventAddHandle(STDIN_FILENO, - VIR_EVENT_HANDLE_READABLE, - virConsoleEventOnStdin, - con, - NULL); - con->stdoutWatch = virEventAddHandle(STDOUT_FILENO, - 0, - virConsoleEventOnStdout, - con, - NULL); + virObjectRef(con); + if ((con->stdoutWatch = virEventAddHandle(STDOUT_FILENO, + 0, + virConsoleEventOnStdout, + con, + virObjectFreeCallback)) < 0) { + virObjectUnref(con); + goto cleanup; + } - virStreamEventAddCallback(con->st, - VIR_STREAM_EVENT_READABLE, - virConsoleEventOnStream, - con, - NULL); + virObjectRef(con); + if (virStreamEventAddCallback(con->st, + VIR_STREAM_EVENT_READABLE, + virConsoleEventOnStream, + con, + virObjectFreeCallback) < 0) { + virObjectUnref(con); + goto cleanup; + } while (!con->quit) { - if (virCondWait(&con->cond, &con->lock) < 0) { - virMutexUnlock(&con->lock); + if (virCondWait(&con->cond, &con->parent.lock) < 0) { VIR_ERROR(_("unable to wait on console condition")); goto cleanup; } } - virMutexUnlock(&con->lock); - ret = 0; cleanup: - virConsoleFree(con); + virConsoleShutdown(con);

+ virObjectUnlock(con); + virObjectUnref(con); /* Restore original signal handlers */ sigaction(SIGQUIT, &old_sigquit, NULL);