[libvirt] [PATCH v2 6/6] streams: Report errors if sendAll/recvAll callbacks fail

We have couple of wrappers over our low level stream APIs: virSreamRecvAll(), virStreamSendAll() and their sparse stream variants. All of them take some callbacks and call them at appropriate times. If a callback fails it aborts the whole operation. However, if it so happens that the callback fails without setting any error users are left with very unhelpful error message: error: cannot receive data from volume fedora.img error: An error occurred, but the cause is unknown One way to avoid it is to report error if callback hasn't. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/libvirt-stream.c | 41 +++++++++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/src/libvirt-stream.c b/src/libvirt-stream.c index 1594ed212..efdbc9e44 100644 --- a/src/libvirt-stream.c +++ b/src/libvirt-stream.c @@ -596,8 +596,12 @@ virStreamSendAll(virStreamPtr stream, for (;;) { int got, offset = 0; got = (handler)(stream, bytes, want, opaque); - if (got < 0) + if (got < 0) { + if (!virGetLastError()) + virReportError(VIR_ERR_OPERATION_FAILED, "%s", + _("send handler failed")); goto cleanup; + } if (got == 0) break; while (offset < got) { @@ -733,16 +737,21 @@ int virStreamSparseSendAll(virStreamPtr stream, const unsigned int skipFlags = 0; if (!dataLen) { - if (holeHandler(stream, &inData, &sectionLen, opaque) < 0) + if (holeHandler(stream, &inData, &sectionLen, opaque) < 0) { + if (!virGetLastError()) + virReportError(VIR_ERR_OPERATION_FAILED, "%s", + _("send holeHandler failed")); goto cleanup; + } if (!inData && sectionLen) { if (virStreamSendHole(stream, sectionLen, skipFlags) < 0) goto cleanup; if (skipHandler(stream, sectionLen, opaque) < 0) { - virReportSystemError(errno, "%s", - _("unable to skip hole")); + if (!virGetLastError()) + virReportError(VIR_ERR_OPERATION_FAILED, "%s", + _("send skipHandler failed")); goto cleanup; } continue; @@ -755,8 +764,12 @@ int virStreamSparseSendAll(virStreamPtr stream, want = dataLen; got = (handler)(stream, bytes, want, opaque); - if (got < 0) + if (got < 0) { + if (!virGetLastError()) + virReportError(VIR_ERR_OPERATION_FAILED, "%s", + _("send handler failed")); goto cleanup; + } if (got == 0) break; while (offset < got) { @@ -862,8 +875,12 @@ virStreamRecvAll(virStreamPtr stream, while (offset < got) { int done; done = (handler)(stream, bytes + offset, got - offset, opaque); - if (done < 0) + if (done < 0) { + if (!virGetLastError()) + virReportError(VIR_ERR_OPERATION_FAILED, "%s", + _("receive handler failed")); goto cleanup; + } offset += done; } } @@ -976,8 +993,12 @@ virStreamSparseRecvAll(virStreamPtr stream, if (virStreamRecvHole(stream, &holeLen, holeFlags) < 0) goto cleanup; - if (holeHandler(stream, holeLen, opaque) < 0) + if (holeHandler(stream, holeLen, opaque) < 0) { + if (!virGetLastError()) + virReportError(VIR_ERR_OPERATION_FAILED, "%s", + _("receive holeHandler failed")); goto cleanup; + } continue; } else if (got < 0) { goto cleanup; @@ -987,8 +1008,12 @@ virStreamSparseRecvAll(virStreamPtr stream, while (offset < got) { int done; done = (handler)(stream, bytes + offset, got - offset, opaque); - if (done < 0) + if (done < 0) { + if (!virGetLastError()) + virReportError(VIR_ERR_OPERATION_FAILED, "%s", + _("receive handler failed")); goto cleanup; + } offset += done; } } -- 2.13.0