On 11/12/2015 12:19 PM, Daniel P. Berrange wrote:
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@redhat.com> --- src/qemu/qemu_domain.c | 178 +++++++++++++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_domain.h | 22 ++++++ 2 files changed, 200 insertions(+)
[...]
+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; + } + }
should 'pos' be initialized here? Otherwise the first ContextRead would use ctxt->pos == 0
+ + virObjectUnref(cfg); + return ctxt; + + error: + virObjectUnref(cfg); + qemuDomainLogContextFree(ctxt); + return NULL; +} + +
[...]
+ +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"));
Coverity points out buf is leaked.
+ return -1; + } + + buf[got] = '\0'; + + ignore_value(VIR_REALLOC_N_QUIET(buf, got + 1)); + *msg = buf; + + return got; +} + +
ACK with the obvious adjustment - not quite sure how to handle 'pos' (yet) - although perhaps future patches will allow the light to shine. John