Introduce a qemuDomainLogContext object to encapsulate
handling of I/O to/from the domain log file. This will
hide details of the log file implementation from the
rest of the driver, making it easier to introduce
support for virtlogd later.
Signed-off-by: Daniel P. Berrange <berrange@xxxxxxxxxx>
---
src/qemu/qemu_domain.c | 178 +++++++++++++++++++++++++++++++++++++++++++++++++
src/qemu/qemu_domain.h | 22 ++++++
2 files changed, 200 insertions(+)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 1dd3cee..e92f8b4 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -40,6 +40,7 @@
#include "virstoragefile.h"
#include "virstring.h"
#include "virthreadjob.h"
+#include "viratomic.h"
#include "storage/storage_driver.h"
@@ -76,6 +77,13 @@ VIR_ENUM_IMPL(qemuDomainAsyncJob, QEMU_ASYNC_JOB_LAST,
);
+struct _qemuDomainLogContext {
+ int refs;
+ int writefd;
+ int readfd;
+ off_t pos;
+};
+
const char *
qemuDomainAsyncJobPhaseToString(qemuDomainAsyncJob job,
int phase ATTRIBUTE_UNUSED)
@@ -2228,6 +2236,176 @@ void qemuDomainObjCheckNetTaint(virQEMUDriverPtr driver,
}
+qemuDomainLogContextPtr qemuDomainLogContextNew(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ qemuDomainLogContextMode mode)
+{
+ virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
+ qemuDomainLogContextPtr ctxt = NULL;
+ char *logfile = NULL;
+
+ if (VIR_ALLOC(ctxt) < 0)
+ goto error;
+
+ ctxt->writefd = -1;
+ ctxt->readfd = -1;
+ virAtomicIntSet(&ctxt->refs, 1);
+
+ if (virAsprintf(&logfile, "%s/%s.log", cfg->logDir, vm->def->name) < 0)
+ goto error;
+
+ if ((ctxt->writefd = open(logfile, O_WRONLY | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR)) < 0) {
+ virReportSystemError(errno, _("failed to create logfile %s"),
+ logfile);
+ goto error;
+ }
+ if (virSetCloseExec(ctxt->writefd) < 0) {
+ virReportSystemError(errno, _("failed to set close-on-exec flag on %s"),
+ logfile);
+ goto error;
+ }
+
+ /* For unprivileged startup we must truncate the file since
+ * we can't rely on logrotate. We don't use O_TRUNC since
+ * it is better for SELinux policy if we truncate afterwards */
+ if (mode == QEMU_DOMAIN_LOG_CONTEXT_MODE_START &&
+ !virQEMUDriverIsPrivileged(driver) &&
+ ftruncate(ctxt->writefd, 0) < 0) {
+ virReportSystemError(errno, _("failed to truncate %s"),
+ logfile);
+ goto error;
+ }
+
+ if (mode == QEMU_DOMAIN_LOG_CONTEXT_MODE_START) {
+ if ((ctxt->readfd = open(logfile, O_RDONLY, S_IRUSR | S_IWUSR)) < 0) {
+ virReportSystemError(errno, _("failed to open logfile %s"),
+ logfile);
+ goto error;
+ }
+ if (virSetCloseExec(ctxt->readfd) < 0) {
+ virReportSystemError(errno, _("failed to set close-on-exec flag on %s"),
+ logfile);
+ goto error;
+ }
+ }
+
+ virObjectUnref(cfg);
+ return ctxt;
+
+ error:
+ virObjectUnref(cfg);
+ qemuDomainLogContextFree(ctxt);
+ return NULL;
+}
+
+
+int qemuDomainLogContextWrite(qemuDomainLogContextPtr ctxt,
+ const char *fmt, ...)
+{
+ va_list argptr;
+ char *message = NULL;
+ int ret = -1;
+
+ va_start(argptr, fmt);
+
+ if (virVasprintf(&message, fmt, argptr) < 0)
+ goto cleanup;
+ if (lseek(ctxt->writefd, 0, SEEK_END) < 0) {
+ virReportSystemError(errno, "%s",
+ _("Unable to see to end of domain logfile"));
+ goto cleanup;
+ }
+ if (safewrite(ctxt->writefd, message, strlen(message)) < 0) {
+ virReportSystemError(errno, "%s",
+ _("Unable to write to domain logfile"));
+ goto cleanup;
+ }
+
+ ret = 0;
+
+ cleanup:
+ va_end(argptr);
+ VIR_FREE(message);
+ return ret;
+}
+
+
+ssize_t qemuDomainLogContextRead(qemuDomainLogContextPtr ctxt,
+ char **msg)
+{
+ char *buf;
+ size_t buflen = 1024 * 128;
+ ssize_t got;
+
+ /* Best effort jump to start of messages */
+ ignore_value(lseek(ctxt->readfd, ctxt->pos, SEEK_SET));
+
+ if (VIR_ALLOC_N(buf, buflen) < 0)
+ return -1;
+
+ got = saferead(ctxt->readfd, buf, buflen - 1);
+ if (got < 0) {
+ virReportSystemError(errno, "%s",
+ _("Unable to read from log file"));
+ return -1;
+ }
+
+ buf[got] = '\0';
+
+ ignore_value(VIR_REALLOC_N_QUIET(buf, got + 1));
+ *msg = buf;
+
+ return got;
+}
+
+
+int qemuDomainLogContextGetWriteFD(qemuDomainLogContextPtr ctxt)
+{
+ return ctxt->writefd;
+}
+
+
+int qemuDomainLogContextGetReadFD(qemuDomainLogContextPtr ctxt)
+{
+ return ctxt->readfd;
+}
+
+
+void qemuDomainLogContextMarkPosition(qemuDomainLogContextPtr ctxt)
+{
+ ctxt->pos = lseek(ctxt->writefd, 0, SEEK_END);
+}
+
+
+off_t qemuDomainLogContextGetPosition(qemuDomainLogContextPtr ctxt)
+{
+ return ctxt->pos;
+}
+
+
+void qemuDomainLogContextRef(qemuDomainLogContextPtr ctxt)
+{
+ virAtomicIntInc(&ctxt->refs);
+}
+
+
+void qemuDomainLogContextFree(qemuDomainLogContextPtr ctxt)
+{
+ bool lastRef;
+
+ if (!ctxt)
+ return;
+
+ lastRef = virAtomicIntDecAndTest(&ctxt->refs);
+ if (!lastRef)
+ return;
+
+ VIR_FORCE_CLOSE(ctxt->writefd);
+ VIR_FORCE_CLOSE(ctxt->readfd);
+ VIR_FREE(ctxt);
+}
+
+
static int
qemuDomainOpenLogHelper(virQEMUDriverConfigPtr cfg,
virDomainObjPtr vm,
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 16dc93c..fa0b14c 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -244,6 +244,9 @@ struct qemuProcessEvent {
void *data;
};
+typedef struct _qemuDomainLogContext qemuDomainLogContext;
+typedef qemuDomainLogContext *qemuDomainLogContextPtr;
+
const char *qemuDomainAsyncJobPhaseToString(qemuDomainAsyncJob job,
int phase);
int qemuDomainAsyncJobPhaseFromString(qemuDomainAsyncJob job,
@@ -348,6 +351,25 @@ void qemuDomainObjCheckNetTaint(virQEMUDriverPtr driver,
virDomainNetDefPtr net,
int logFD);
+typedef enum {
+ QEMU_DOMAIN_LOG_CONTEXT_MODE_START,
+ QEMU_DOMAIN_LOG_CONTEXT_MODE_ATTACH,
+ QEMU_DOMAIN_LOG_CONTEXT_MODE_STOP,
+} qemuDomainLogContextMode;
+
+qemuDomainLogContextPtr qemuDomainLogContextNew(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ qemuDomainLogContextMode mode);
+int qemuDomainLogContextWrite(qemuDomainLogContextPtr ctxt,
+ const char *fmt, ...) ATTRIBUTE_FMT_PRINTF(2, 3);
+ssize_t qemuDomainLogContextRead(qemuDomainLogContextPtr ctxt,
+ char **msg);
+int qemuDomainLogContextGetWriteFD(qemuDomainLogContextPtr ctxt);
+int qemuDomainLogContextGetReadFD(qemuDomainLogContextPtr ctxt);
+void qemuDomainLogContextMarkPosition(qemuDomainLogContextPtr ctxt);
+off_t qemuDomainLogContextGetPosition(qemuDomainLogContextPtr ctxt);
+void qemuDomainLogContextRef(qemuDomainLogContextPtr ctxt);
+void qemuDomainLogContextFree(qemuDomainLogContextPtr ctxt);
int qemuDomainCreateLog(virQEMUDriverPtr driver, virDomainObjPtr vm, bool append);
int qemuDomainOpenLog(virQEMUDriverPtr driver, virDomainObjPtr vm);
--
2.5.0
--
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