Re: [libvirt] [PATCH v2 07/20] virlog: Introduce virLogNewOutputTo* as a replacement for virLogAddOutputTo*

Continuing with the effort to split output parsing and defining, these new functions return a logging object reference instead of defining the output. Eventually, these functions will replace the existing ones (virLogAddOutputTo*) which will then be dropped. Also, make the new functions non-static, so they can be introduced prior to usage and the compiler won't complain (will be switched back to static once the usage is sorted out by later patches). Signed-off-by: Erik Skultety <eskultet(a)redhat.com&gt; --- src/libvirt_private.syms | 4 ++ src/util/virlog.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++ src/util/virlog.h | 6 +++ 3 files changed, 108 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 0bceba7..39b0270 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1857,6 +1857,10 @@ virLogGetNbOutputs; virLogGetOutputs; virLogLock; virLogMessage; +virLogNewOutputToFile; +virLogNewOutputToJournald; +virLogNewOutputToStderr; +virLogNewOutputToSyslog; virLogOutputFree; virLogOutputListFree; virLogOutputNew;

diff --git a/src/util/virlog.c b/src/util/virlog.c index a74967b..c0b8b9a 100644 --- a/src/util/virlog.c +++ b/src/util/virlog.c @@ -780,6 +780,14 @@ virLogAddOutputToStderr(virLogPriority priority) } +virLogOutputPtr

+virLogNewOutputToStderr(virLogPriority priority) +{ + return virLogOutputNew(virLogOutputToFd, NULL, (void *)2L, priority, + VIR_LOG_TO_STDERR, NULL);

+} + + static int virLogAddOutputToFile(virLogPriority priority, const char *file) @@ -799,6 +807,27 @@ virLogAddOutputToFile(virLogPriority priority, } +virLogOutputPtr +virLogNewOutputToFile(virLogPriority priority, + const char *file) +{ + int fd; + virLogOutputPtr ret = NULL; + + fd = open(file, O_CREAT | O_APPEND | O_WRONLY, S_IRUSR | S_IWUSR); + if (fd < 0) + return NULL; + + if (!(ret = virLogOutputNew(virLogOutputToFd, virLogCloseFd, + (void *)(intptr_t)fd, + priority, VIR_LOG_TO_FILE, file))) { + VIR_LOG_CLOSE(fd); + return NULL; + } + return ret; +} + + #if HAVE_SYSLOG_H || USE_JOURNALD /* Compat in case we build with journald, but no syslog */ @@ -886,6 +915,51 @@ virLogAddOutputToSyslog(virLogPriority priority, } +virLogOutputPtr +virLogNewOutputToSyslog(virLogPriority priority, + const char *ident) +{ + virLogOutputPtr ret = NULL; + int at = -1; + + /* There are a couple of issues with syslog: + * 1) If we re-opened the connection by calling openlog now, it would change + * the message tag immediately which is not what we want, since we might be + * in the middle of parsing of a new set of outputs where anything still can + * go wrong and we would introduce an inconsistent state to the log. We're + * also not holding a lock on the logger if we tried to change the tag + * while other workers are actively logging. + * + * 2) Syslog keeps the open file descriptor private, so we can't just dup() + * it like we would do with files if an output already existed. + * + * If a syslog connection already exists changing the message tag has to be + * therefore special-cased and postponed until the very last moment. + */ + if ((at = virLogFindOutput(virLogOutputs, virLogNbOutputs, + VIR_LOG_TO_SYSLOG, NULL)) < 0) { + /* + * rather than copying @ident, syslog uses caller's reference instead + */ + VIR_FREE(current_ident); + if (VIR_STRDUP(current_ident, ident) < 0) + return NULL; + + openlog(current_ident, 0, 0); + } + + if (!(ret = virLogOutputNew(virLogOutputToSyslog, virLogCloseSyslog, + NULL, priority, VIR_LOG_TO_SYSLOG, ident))) { + if (at < 0) { + closelog(); + VIR_FREE(current_ident); + } + return NULL; + } + return ret; +} + + # if USE_JOURNALD # define IOVEC_SET(iov, data, size) \ do { \ @@ -1102,6 +1176,30 @@ static int virLogAddOutputToJournald(int priority) } return 0; } + + +virLogOutputPtr +virLogNewOutputToJournald(int priority) +{ + virLogOutputPtr ret = NULL; + + if ((journalfd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) + return NULL; + + if (virSetInherit(journalfd, false) < 0) { + VIR_LOG_CLOSE(journalfd); + return NULL; + } + + if (!(ret = virLogOutputNew(virLogOutputToJournald, + virLogCloseJournald, NULL,

+ priority, VIR_LOG_TO_JOURNALD, NULL))) { + VIR_LOG_CLOSE(journalfd); + return NULL; + } + + return ret; +} # endif /* USE_JOURNALD */ int virLogPriorityFromSyslog(int priority) diff --git a/src/util/virlog.h b/src/util/virlog.h index e0fe008..e3d5243 100644 --- a/src/util/virlog.h +++ b/src/util/virlog.h @@ -239,5 +239,11 @@ int virLogFindOutput(virLogOutputPtr *outputs, size_t noutputs, virLogDestination dest, const void *opaque); int virLogDefineOutputs(virLogOutputPtr *outputs, size_t noutputs); int virLogDefineFilters(virLogFilterPtr *filters, size_t nfilters); +virLogOutputPtr virLogNewOutputToStderr(virLogPriority priority); +virLogOutputPtr virLogNewOutputToFile(virLogPriority priority, + const char *file); +virLogOutputPtr virLogNewOutputToSyslog(virLogPriority priority, + const char *ident); +virLogOutputPtr virLogNewOutputToJournald(int priority);

#endif