[libvirt] [PATCH v3 0/5] tools: console: fixes and improvments
Diff from v2[1] - split first patch further into 2 [1] https://www.redhat.com/archives/libvir-list/2019-March/msg00812.html Nikolay Shirokovskiy (5): tools: console: make console virLockableObject tools: console: cleanup console on errors in main thread tools: console: add missing locks in callbacks tools: console: check if console was shutdown in callbacks tools: console: pass stream/fd errors to user tools/virsh-console.c | 224 ++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 171 insertions(+), 53 deletions(-) -- 1.8.3.1
We need to turn console into virObject object because stream/fd callbacks can be called from the event loop thread after freeing console in main thread. It is convinient to turn into virLockableObject as we have mutex in console object. Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 74 ++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 55 insertions(+), 19 deletions(-) diff --git a/tools/virsh-console.c b/tools/virsh-console.c index 045a636..763b395 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); } @@ -288,6 +300,35 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, } +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; +} + + static char virshGetEscapeChar(const char *s) { @@ -324,6 +365,11 @@ 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 +379,6 @@ 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); @@ -345,11 +388,6 @@ virshRunConsole(vshControl *ctl, if (virDomainOpenConsole(dom, dev_name, con->st, flags) < 0) goto cleanup; - if (virCondInit(&con->cond) < 0 || virMutexInit(&con->lock) < 0) - goto cleanup; - - virMutexLock(&con->lock); - con->stdinWatch = virEventAddHandle(STDIN_FILENO, VIR_EVENT_HANDLE_READABLE, virConsoleEventOnStdin, @@ -368,19 +406,17 @@ virshRunConsole(vshControl *ctl, NULL); 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); + virObjectUnlock(con); + virObjectUnref(con); /* Restore original signal handlers */ sigaction(SIGQUIT, &old_sigquit, NULL); -- 1.8.3.1
On 3/18/19 5:08 AM, Nikolay Shirokovskiy wrote:
We need to turn console into virObject object because stream/fd callbacks can be called from the event loop thread after freeing console in main thread. It is convinient to turn into virLockableObject as we have mutex in console object.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 74 ++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 55 insertions(+), 19 deletions(-)
Reviewed-by: Cole Robinson <crobinso@redhat.com> - Cole
We only check now for virObjectWait failures in virshRunConsole but we'd better check and for other failures too. And we need to shutdown console on error in the main thread. Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 52 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 34 insertions(+), 18 deletions(-) diff --git a/tools/virsh-console.c b/tools/virsh-console.c index 763b395..9289221 100644 --- a/tools/virsh-console.c +++ b/tools/virsh-console.c @@ -112,8 +112,10 @@ virConsoleShutdown(virConsolePtr con) virEventRemoveHandle(con->stdoutWatch); con->stdinWatch = -1; con->stdoutWatch = -1; - con->quit = true; - virCondSignal(&con->cond); + if (!con->quit) { + con->quit = true; + virCondSignal(&con->cond); + } } @@ -388,22 +390,35 @@ virshRunConsole(vshControl *ctl, if (virDomainOpenConsole(dom, dev_name, con->st, flags) < 0) goto cleanup; - con->stdinWatch = virEventAddHandle(STDIN_FILENO, - VIR_EVENT_HANDLE_READABLE, - virConsoleEventOnStdin, - con, - NULL); - con->stdoutWatch = virEventAddHandle(STDOUT_FILENO, - 0, - virConsoleEventOnStdout, - con, - NULL); - - virStreamEventAddCallback(con->st, - VIR_STREAM_EVENT_READABLE, - virConsoleEventOnStream, - con, - NULL); + virObjectRef(con); + if ((con->stdinWatch = virEventAddHandle(STDIN_FILENO, + VIR_EVENT_HANDLE_READABLE, + virConsoleEventOnStdin, + con, + virObjectFreeCallback)) < 0) { + virObjectUnref(con); + goto cleanup; + } + + virObjectRef(con); + if ((con->stdoutWatch = virEventAddHandle(STDOUT_FILENO, + 0, + virConsoleEventOnStdout, + con, + virObjectFreeCallback)) < 0) { + virObjectUnref(con); + goto cleanup; + } + + 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->parent.lock) < 0) { @@ -415,6 +430,7 @@ virshRunConsole(vshControl *ctl, ret = 0; cleanup: + virConsoleShutdown(con); virObjectUnlock(con); virObjectUnref(con); -- 1.8.3.1
On 3/18/19 5:08 AM, Nikolay Shirokovskiy wrote:
We only check now for virObjectWait failures in virshRunConsole but we'd better check and for other failures too. And we need to shutdown console on error in the main thread.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 52 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 34 insertions(+), 18 deletions(-)
diff --git a/tools/virsh-console.c b/tools/virsh-console.c index 763b395..9289221 100644 --- a/tools/virsh-console.c +++ b/tools/virsh-console.c @@ -112,8 +112,10 @@ virConsoleShutdown(virConsolePtr con) virEventRemoveHandle(con->stdoutWatch); con->stdinWatch = -1; con->stdoutWatch = -1; - con->quit = true; - virCondSignal(&con->cond); + if (!con->quit) { + con->quit = true; + virCondSignal(&con->cond); + } }
@@ -388,22 +390,35 @@ virshRunConsole(vshControl *ctl, if (virDomainOpenConsole(dom, dev_name, con->st, flags) < 0) goto cleanup;
- con->stdinWatch = virEventAddHandle(STDIN_FILENO, - VIR_EVENT_HANDLE_READABLE, - virConsoleEventOnStdin, - con, - NULL); - con->stdoutWatch = virEventAddHandle(STDOUT_FILENO, - 0, - virConsoleEventOnStdout, - con, - NULL); - - virStreamEventAddCallback(con->st, - VIR_STREAM_EVENT_READABLE, - virConsoleEventOnStream, - con, - NULL); + virObjectRef(con); + if ((con->stdinWatch = virEventAddHandle(STDIN_FILENO, + VIR_EVENT_HANDLE_READABLE, + virConsoleEventOnStdin, + con, + virObjectFreeCallback)) < 0) { + virObjectUnref(con); + goto cleanup; + } + + virObjectRef(con); + if ((con->stdoutWatch = virEventAddHandle(STDOUT_FILENO, + 0, + virConsoleEventOnStdout, + con, + virObjectFreeCallback)) < 0) { + virObjectUnref(con); + goto cleanup; + } + + virObjectRef(con); + if (virStreamEventAddCallback(con->st, + VIR_STREAM_EVENT_READABLE, + virConsoleEventOnStream, + con, + virObjectFreeCallback) < 0) { + virObjectUnref(con); + goto cleanup; + }
I didn't understand this pattern at first, but I see it's used by the qemu agent and monitor callbacks and it makes sense after refreshing my event loop memory: we add a reference because the loop callback carries around 'con' as an opaque data value, which is unref'd when the event handle is removed.
while (!con->quit) { if (virCondWait(&con->cond, &con->parent.lock) < 0) { @@ -415,6 +430,7 @@ virshRunConsole(vshControl *ctl, ret = 0;
cleanup: + virConsoleShutdown(con); virObjectUnlock(con); virObjectUnref(con);
And we need this here to actually trigger the handle unregistering, incase one of the Add* calls fails. So makes sense to me Reviewed-by: Cole Robinson <crobinso@redhat.com> - Cole
Stream/fd callbacks accessing console object are called from the event loop thread and the console object is also accessed from the main thread so we are better add locking to handlers. Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/tools/virsh-console.c b/tools/virsh-console.c index 9289221..3dae707 100644 --- a/tools/virsh-console.c +++ b/tools/virsh-console.c @@ -137,6 +137,8 @@ virConsoleEventOnStream(virStreamPtr st, { virConsolePtr con = opaque; + virObjectLock(con); + if (events & VIR_STREAM_EVENT_READABLE) { size_t avail = con->streamToTerminal.length - con->streamToTerminal.offset; @@ -146,7 +148,7 @@ 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; @@ -157,10 +159,10 @@ 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) @@ -176,10 +178,10 @@ 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, @@ -201,6 +203,9 @@ virConsoleEventOnStream(virStreamPtr st, events & VIR_STREAM_EVENT_HANGUP) { virConsoleShutdown(con); } + + cleanup: + virObjectUnlock(con); } @@ -212,6 +217,8 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, { virConsolePtr con = opaque; + virObjectLock(con); + if (events & VIR_EVENT_HANDLE_READABLE) { size_t avail = con->terminalToStream.length - con->terminalToStream.offset; @@ -221,7 +228,7 @@ 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; @@ -234,15 +241,15 @@ 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; @@ -256,6 +263,9 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, events & VIR_EVENT_HANDLE_HANGUP) { virConsoleShutdown(con); } + + cleanup: + virObjectUnlock(con); } @@ -267,6 +277,8 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, { virConsolePtr con = opaque; + virObjectLock(con); + if (events & VIR_EVENT_HANDLE_WRITABLE && con->streamToTerminal.offset) { ssize_t done; @@ -277,7 +289,7 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, if (done < 0) { if (errno != EAGAIN) virConsoleShutdown(con); - return; + goto cleanup; } memmove(con->streamToTerminal.data, con->streamToTerminal.data + done, @@ -299,6 +311,9 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, events & VIR_EVENT_HANDLE_HANGUP) { virConsoleShutdown(con); } + + cleanup: + virObjectUnlock(con); } -- 1.8.3.1
On 3/18/19 5:08 AM, Nikolay Shirokovskiy wrote:
Stream/fd callbacks accessing console object are called from the event loop thread and the console object is also accessed from the main thread so we are better add locking to handlers.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-)
The qemuAgentIO and qemuMonitorIO callbacks also add have matching Ref/Unref calls along side the lock calls, but after scratching my head over it for a while I don't think it's necessary here: even if virConsoleShutdown is called from one of the callbacks, the main thread will still hold a reference until the callback releases the object lock Reviewed-by: Cole Robinson <crobinso@redhat.com> - Cole
On 03.04.2019 23:44, Cole Robinson wrote:
On 3/18/19 5:08 AM, Nikolay Shirokovskiy wrote:
Stream/fd callbacks accessing console object are called from the event loop thread and the console object is also accessed from the main thread so we are better add locking to handlers.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-)
The qemuAgentIO and qemuMonitorIO callbacks also add have matching Ref/Unref calls along side the lock calls, but after scratching my head over it for a while I don't think it's necessary here: even if virConsoleShutdown is called from one of the callbacks, the main thread will still hold a reference until the callback releases the object lock
We don't need even to rely on main thread. Event loop itself has a reference which will be unrefed only after callback returns. Nikolay
On 4/4/19 2:57 AM, Nikolay Shirokovskiy wrote:
On 03.04.2019 23:44, Cole Robinson wrote:
On 3/18/19 5:08 AM, Nikolay Shirokovskiy wrote:
Stream/fd callbacks accessing console object are called from the event loop thread and the console object is also accessed from the main thread so we are better add locking to handlers.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-)
The qemuAgentIO and qemuMonitorIO callbacks also add have matching Ref/Unref calls along side the lock calls, but after scratching my head over it for a while I don't think it's necessary here: even if virConsoleShutdown is called from one of the callbacks, the main thread will still hold a reference until the callback releases the object lock
We don't need even to rely on main thread. Event loop itself has a reference which will be unrefed only after callback returns.
Hmm interesting, where in the code is that exactly? I know we pass a Free callback to virEventAddHandle but that's only called when the handle is removed, not after the callback is invoked. Maybe I'm missing something Thanks, Cole
On 04.04.2019 17:48, Cole Robinson wrote:
On 4/4/19 2:57 AM, Nikolay Shirokovskiy wrote:
On 03.04.2019 23:44, Cole Robinson wrote:
On 3/18/19 5:08 AM, Nikolay Shirokovskiy wrote:
Stream/fd callbacks accessing console object are called from the event loop thread and the console object is also accessed from the main thread so we are better add locking to handlers.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-)
The qemuAgentIO and qemuMonitorIO callbacks also add have matching Ref/Unref calls along side the lock calls, but after scratching my head over it for a while I don't think it's necessary here: even if virConsoleShutdown is called from one of the callbacks, the main thread will still hold a reference until the callback releases the object lock
We don't need even to rely on main thread. Event loop itself has a reference which will be unrefed only after callback returns.
Hmm interesting, where in the code is that exactly? I know we pass a Free callback to virEventAddHandle but that's only called when the handle is removed, not after the callback is invoked. Maybe I'm missing something
The reason we are ok is that when we call virEventPollRemoveHandle it only marks handle to be removed so that if this call is done from callback we don't free opaque object immediately. Only after callback is finished we call virEventPollCleanupHandles which actually do freeing. Nikolay
On error in main thread virConsoleShutdown is called which deletes fd watches/stream callback and yet callbacks can be called after. Thus we can incorrectly allocate terminalToStream.data memory and get memory leak for example. Let's check if console was shutdown in the very beginning of callbacks. Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/tools/virsh-console.c b/tools/virsh-console.c index 3dae707..d109734 100644 --- a/tools/virsh-console.c +++ b/tools/virsh-console.c @@ -139,6 +139,10 @@ virConsoleEventOnStream(virStreamPtr st, virObjectLock(con); + /* we got late event after console was shutdown */ + if (!con->st) + goto cleanup; + if (events & VIR_STREAM_EVENT_READABLE) { size_t avail = con->streamToTerminal.length - con->streamToTerminal.offset; @@ -219,6 +223,10 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, virObjectLock(con); + /* we got late event after console was shutdown */ + if (!con->st) + goto cleanup; + if (events & VIR_EVENT_HANDLE_READABLE) { size_t avail = con->terminalToStream.length - con->terminalToStream.offset; @@ -279,6 +287,10 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, virObjectLock(con); + /* we got late event after console was shutdown */ + if (!con->st) + goto cleanup; + if (events & VIR_EVENT_HANDLE_WRITABLE && con->streamToTerminal.offset) { ssize_t done; -- 1.8.3.1
On 3/18/19 5:08 AM, Nikolay Shirokovskiy wrote:
On error in main thread virConsoleShutdown is called which deletes fd watches/stream callback and yet callbacks can be called after. Thus we can incorrectly allocate terminalToStream.data memory and get memory leak for example. Let's check if console was shutdown in the very beginning of callbacks.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/tools/virsh-console.c b/tools/virsh-console.c index 3dae707..d109734 100644 --- a/tools/virsh-console.c +++ b/tools/virsh-console.c @@ -139,6 +139,10 @@ virConsoleEventOnStream(virStreamPtr st,
virObjectLock(con);
+ /* we got late event after console was shutdown */ + if (!con->st) + goto cleanup; + if (events & VIR_STREAM_EVENT_READABLE) { size_t avail = con->streamToTerminal.length - con->streamToTerminal.offset; @@ -219,6 +223,10 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED,
virObjectLock(con);
+ /* we got late event after console was shutdown */ + if (!con->st) + goto cleanup; + if (events & VIR_EVENT_HANDLE_READABLE) { size_t avail = con->terminalToStream.length - con->terminalToStream.offset; @@ -279,6 +287,10 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED,
virObjectLock(con);
+ /* we got late event after console was shutdown */ + if (!con->st) + goto cleanup; + if (events & VIR_EVENT_HANDLE_WRITABLE && con->streamToTerminal.offset) { ssize_t done;
I didn't verify exactly how this case can happen but it seems sane, so: Reviewed-by: Cole Robinson <crobinso@redhat.com> - Cole
If the console was disconnected due to a connection problem or a problem on the server side it is convinient to provide the cause to the user. If the error come from the API then the error is saved in a virsh global variable. However, since success is returned from virshRunConsole after we reach the waiting stage, then the error is never reported. Let's track the error in the event loop. Next after failure we do a cleanup and this cleanup can overwrite root cause. Thus let's save root cause immediately and then set it to virsh error after all cleanup is done. Since we'll be sending the error to the consumer, each failure path from the event handlers needs to be augmented to provide what error generated the failure. Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 55 +++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 47 insertions(+), 8 deletions(-) diff --git a/tools/virsh-console.c b/tools/virsh-console.c index d109734..236933a 100644 --- a/tools/virsh-console.c +++ b/tools/virsh-console.c @@ -73,6 +73,7 @@ struct virConsole { struct virConsoleBuffer terminalToStream; char escapeChar; + virError error; }; static virClassPtr virConsoleClass; @@ -98,6 +99,11 @@ virConsoleHandleSignal(int sig ATTRIBUTE_UNUSED) static void virConsoleShutdown(virConsolePtr con) { + virErrorPtr err = virGetLastError(); + + if (con->error.code == VIR_ERR_OK && err && err->code != VIR_ERR_OK) + virCopyLastError(&con->error); + if (con->st) { virStreamEventRemoveCallback(con->st); virStreamAbort(con->st); @@ -128,6 +134,7 @@ virConsoleDispose(void *obj) virStreamFree(con->st); virCondDestroy(&con->cond); + virResetError(&con->error); } @@ -165,6 +172,10 @@ virConsoleEventOnStream(virStreamPtr st, if (got == -2) goto cleanup; /* blocking */ if (got <= 0) { + if (got == 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("console stream EOF")); + } virConsoleShutdown(con); goto cleanup; } @@ -247,11 +258,14 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, con->terminalToStream.offset, avail); if (got < 0) { - if (errno != EAGAIN) + if (errno != EAGAIN) { + virReportSystemError(errno, "%s", _("cannot read from stdin")); virConsoleShutdown(con); + } goto cleanup; } if (got == 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("EOF on stdin")); virConsoleShutdown(con); goto cleanup; } @@ -267,9 +281,16 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED, VIR_STREAM_EVENT_WRITABLE); } - if (events & VIR_EVENT_HANDLE_ERROR || - events & VIR_EVENT_HANDLE_HANGUP) { + if (events & VIR_EVENT_HANDLE_ERROR) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("IO error on stdin")); virConsoleShutdown(con); + goto cleanup; + } + + if (events & VIR_EVENT_HANDLE_HANGUP) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("EOF on stdin")); + virConsoleShutdown(con); + goto cleanup; } cleanup: @@ -299,8 +320,10 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, con->streamToTerminal.data, con->streamToTerminal.offset); if (done < 0) { - if (errno != EAGAIN) + if (errno != EAGAIN) { + virReportSystemError(errno, "%s", _("cannot write to stdout")); virConsoleShutdown(con); + } goto cleanup; } memmove(con->streamToTerminal.data, @@ -319,9 +342,16 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED, if (!con->streamToTerminal.offset) virEventUpdateHandle(con->stdoutWatch, 0); - if (events & VIR_EVENT_HANDLE_ERROR || - events & VIR_EVENT_HANDLE_HANGUP) { + if (events & VIR_EVENT_HANDLE_ERROR) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("IO error stdout")); virConsoleShutdown(con); + goto cleanup; + } + + if (events & VIR_EVENT_HANDLE_HANGUP) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("EOF on stdout")); + virConsoleShutdown(con); + goto cleanup; } cleanup: @@ -449,15 +479,24 @@ virshRunConsole(vshControl *ctl, while (!con->quit) { if (virCondWait(&con->cond, &con->parent.lock) < 0) { - VIR_ERROR(_("unable to wait on console condition")); + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("unable to wait on console condition")); goto cleanup; } } - ret = 0; + if (con->error.code == VIR_ERR_OK) + ret = 0; cleanup: virConsoleShutdown(con); + + if (ret < 0) { + vshResetLibvirtError(); + virSetError(&con->error); + vshSaveLibvirtHelperError(); + } + virObjectUnlock(con); virObjectUnref(con); -- 1.8.3.1
On 3/18/19 5:08 AM, Nikolay Shirokovskiy wrote:
If the console was disconnected due to a connection problem or a problem on the server side it is convinient to provide the cause to the user. If the error come from the API then the error is saved in a virsh global variable. However, since success is returned from virshRunConsole after we reach the waiting stage, then the error is never reported. Let's track the error in the event loop.
Next after failure we do a cleanup and this cleanup can overwrite root cause. Thus let's save root cause immediately and then set it to virsh error after all cleanup is done.
Since we'll be sending the error to the consumer, each failure path from the event handlers needs to be augmented to provide what error generated the failure.
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com> --- tools/virsh-console.c | 55 +++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 47 insertions(+), 8 deletions(-)
diff --git a/tools/virsh-console.c b/tools/virsh-console.c index d109734..236933a 100644 --- a/tools/virsh-console.c +++ b/tools/virsh-console.c @@ -73,6 +73,7 @@ struct virConsole { struct virConsoleBuffer terminalToStream;
char escapeChar; + virError error; };
static virClassPtr virConsoleClass; @@ -98,6 +99,11 @@ virConsoleHandleSignal(int sig ATTRIBUTE_UNUSED) static void virConsoleShutdown(virConsolePtr con) { + virErrorPtr err = virGetLastError(); + + if (con->error.code == VIR_ERR_OK && err && err->code != VIR_ERR_OK) + virCopyLastError(&con->error); +
virGetLastError() returns NULL if err->code == VIR_ERR_OK, so that last check can be removed. The rest looks good to me Reviewed-by: Cole Robinson <crobinso@redhat.com> - Cole
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Cole Robinson -
Nikolay Shirokovskiy