[libvirt] [PATCH 3/4] logging: change log protocol to be more reusable

Friday, 4 December 2015

The current virtlogd RPC protocol provides the ability to
handle log files associated with QEMU stdout/err. The log
protocol messages take the virt driver, domain name and
use that to form a log file path. This is quite restrictive
as it prevents us re-using the same RPC protocol messages
for logging to char device backends where the filename
can be arbitrarily user specified. It is also bad because
it means we have 2 separate locations which have to decide
on logfile name.

This change alters the RPC protocol so that we pass the
desired log file path along when opening the log file
initially. Now the virt driver is exclusively in charge
of deciding the log filename

Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt;
---
 src/logging/log_daemon_dispatch.c |  9 ++---
 src/logging/log_handler.c         | 70 +++------------------------------------
 src/logging/log_handler.h         |  9 ++---
 src/logging/log_manager.c         | 18 ++++------
 src/logging/log_manager.h         |  9 ++---
 src/logging/log_protocol.x        |  7 ++--
 src/qemu/qemu_domain.c            | 43 +++++++++---------------
 7 files changed, 39 insertions(+), 126 deletions(-)

diff --git a/src/logging/log_daemon_dispatch.c b/src/logging/log_daemon_dispatch.c
index 160ab00..da7c414 100644
--- a/src/logging/log_daemon_dispatch.c
+++ b/src/logging/log_daemon_dispatch.c
@@ -55,6 +55,7 @@ virLogManagerProtocolDispatchDomainOpenLogFile(virNetServerPtr server
ATTRIBUTE_
                                              args->driver,
                                              (unsigned char *)args->dom.uuid,
                                              args->dom.name,
+                                             args->path,
                                              &inode, &offset)) < 0)
         goto cleanup;
 
@@ -87,9 +88,7 @@ virLogManagerProtocolDispatchDomainGetLogFilePosition(virNetServerPtr
server ATT
     ino_t inode;
 
     if (virLogHandlerDomainGetLogFilePosition(virLogDaemonGetHandler(logDaemon),
-                                              args->driver,
-                                              (unsigned char *)args->dom.uuid,
-                                              args->dom.name,
+                                              args->path,
                                               &inode, &offset) < 0)
         goto cleanup;
 
@@ -125,9 +124,7 @@ virLogManagerProtocolDispatchDomainReadLogFile(virNetServerPtr server
ATTRIBUTE_
     }
 
     if ((data = virLogHandlerDomainReadLogFile(virLogDaemonGetHandler(logDaemon),
-                                               args->driver,
-                                               (unsigned char *)args->dom.uuid,
-                                               args->dom.name,
+                                               args->path,
                                                args->pos.inode,
                                                args->pos.offset,
                                                args->maxlen)) == NULL)
diff --git a/src/logging/log_handler.c b/src/logging/log_handler.c
index 23c33da..b24826c 100644
--- a/src/logging/log_handler.c
+++ b/src/logging/log_handler.c
@@ -351,59 +351,23 @@ virLogHandlerDispose(void *obj)
 }
 
 
-static char *
-virLogHandlerGetLogFilePathForDomain(virLogHandlerPtr handler,
-                                     const char *driver,
-                                     const unsigned char *domuuid ATTRIBUTE_UNUSED,
-                                     const char *domname)
-{
-    char *path;
-    if (handler->privileged) {
-        if (virAsprintf(&path,
-                        LOCALSTATEDIR "/log/libvirt/%s/%s.log",
-                        driver, domname) < 0)
-            return NULL;
-    } else {
-        char *cachedir;
-
-        cachedir = virGetUserCacheDirectory();
-        if (!cachedir)
-            return NULL;
-
-        if (virAsprintf(&path,
-                        "%s/%s/log/%s.log", cachedir, driver, domname) < 0)
{
-            VIR_FREE(cachedir);
-            return NULL;
-        }
-
-    }
-    return path;
-}
-
-
 int
 virLogHandlerDomainOpenLogFile(virLogHandlerPtr handler,
                                const char *driver,
                                const unsigned char *domuuid ATTRIBUTE_UNUSED,
                                const char *domname,
+                               const char *path,
                                ino_t *inode,
                                off_t *offset)
 {
     size_t i;
     virLogHandlerLogFilePtr file = NULL;
     int pipefd[2] = { -1, -1 };
-    char *path;
 
     virObjectLock(handler);
 
     handler->inhibitor(true, handler->opaque);
 
-    if (!(path = virLogHandlerGetLogFilePathForDomain(handler,
-                                                      driver,
-                                                      domuuid,
-                                                      domname)))
-        goto error;
-
     for (i = 0; i < handler->nfiles; i++) {
         if (STREQ(virRotatingFileWriterGetPath(handler->files[i]->file),
                   path)) {
@@ -449,8 +413,6 @@ virLogHandlerDomainOpenLogFile(virLogHandlerPtr handler,
         goto error;
     }
 
-    VIR_FREE(path);
-
     *inode = virRotatingFileWriterGetINode(file->file);
     *offset = virRotatingFileWriterGetOffset(file->file);
 
@@ -458,7 +420,6 @@ virLogHandlerDomainOpenLogFile(virLogHandlerPtr handler,
     return pipefd[1];
 
  error:
-    VIR_FREE(path);
     VIR_FORCE_CLOSE(pipefd[0]);
     VIR_FORCE_CLOSE(pipefd[1]);
     handler->inhibitor(false, handler->opaque);
@@ -470,25 +431,16 @@ virLogHandlerDomainOpenLogFile(virLogHandlerPtr handler,
 
 int
 virLogHandlerDomainGetLogFilePosition(virLogHandlerPtr handler,
-                                      const char *driver,
-                                      const unsigned char *domuuid,
-                                      const char *domname,
+                                      const char *path,
                                       ino_t *inode,
                                       off_t *offset)
 {
-    char *path;
     virLogHandlerLogFilePtr file = NULL;
     int ret = -1;
     size_t i;
 
     virObjectLock(handler);
 
-    if (!(path = virLogHandlerGetLogFilePathForDomain(handler,
-                                                      driver,
-                                                      domuuid,
-                                                      domname)))
-        goto cleanup;
-
     for (i = 0; i < handler->nfiles; i++) {
         if (STREQ(virRotatingFileWriterGetPath(handler->files[i]->file),
                   path)) {
@@ -499,8 +451,8 @@ virLogHandlerDomainGetLogFilePosition(virLogHandlerPtr handler,
 
     if (!file) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
-                       _("No open log file for domain %s"),
-                       domname);
+                       _("No open log file %s"),
+                       path);
         goto cleanup;
     }
 
@@ -510,7 +462,6 @@ virLogHandlerDomainGetLogFilePosition(virLogHandlerPtr handler,
     ret = 0;
 
  cleanup:
-    VIR_FREE(path);
     virObjectUnlock(handler);
     return ret;
 }
@@ -518,26 +469,17 @@ virLogHandlerDomainGetLogFilePosition(virLogHandlerPtr handler,
 
 char *
 virLogHandlerDomainReadLogFile(virLogHandlerPtr handler,
-                               const char *driver,
-                               const unsigned char *domuuid,
-                               const char *domname,
+                               const char *path,
                                ino_t inode,
                                off_t offset,
                                size_t maxlen)
 {
-    char *path;
     virRotatingFileReaderPtr file = NULL;
     char *data = NULL;
     ssize_t got;
 
     virObjectLock(handler);
 
-    if (!(path = virLogHandlerGetLogFilePathForDomain(handler,
-                                                      driver,
-                                                      domuuid,
-                                                      domname)))
-        goto error;
-
     if (!(file = virRotatingFileReaderNew(path, DEFAULT_MAX_BACKUP)))
         goto error;
 
@@ -554,11 +496,9 @@ virLogHandlerDomainReadLogFile(virLogHandlerPtr handler,
 
     virRotatingFileReaderFree(file);
     virObjectUnlock(handler);
-    VIR_FREE(path);
     return data;
 
  error:
-    VIR_FREE(path);
     VIR_FREE(data);
     virRotatingFileReaderFree(file);
     virObjectUnlock(handler);
diff --git a/src/logging/log_handler.h b/src/logging/log_handler.h
index e41ac7f..6a13072 100644
--- a/src/logging/log_handler.h
+++ b/src/logging/log_handler.h
@@ -47,20 +47,17 @@ int virLogHandlerDomainOpenLogFile(virLogHandlerPtr handler,
                                    const char *driver,
                                    const unsigned char *domuuid,
                                    const char *domname,
+                                   const char *path,
                                    ino_t *inode,
                                    off_t *offset);
 
 int virLogHandlerDomainGetLogFilePosition(virLogHandlerPtr handler,
-                                          const char *driver,
-                                          const unsigned char *domuuid,
-                                          const char *domname,
+                                          const char *path,
                                           ino_t *inode,
                                           off_t *offset);
 
 char *virLogHandlerDomainReadLogFile(virLogHandlerPtr handler,
-                                     const char *driver,
-                                     const unsigned char *domuuid,
-                                     const char *domname,
+                                     const char *path,
                                      ino_t inode,
                                      off_t offset,
                                      size_t maxlen);
diff --git a/src/logging/log_manager.c b/src/logging/log_manager.c
index 7a4c7e2..290e2c8 100644
--- a/src/logging/log_manager.c
+++ b/src/logging/log_manager.c
@@ -156,6 +156,7 @@ virLogManagerDomainOpenLogFile(virLogManagerPtr mgr,
                                const char *driver,
                                const unsigned char *domuuid,
                                const char *domname,
+                               const char *path,
                                unsigned int flags,
                                ino_t *inode,
                                off_t *offset)
@@ -172,6 +173,7 @@ virLogManagerDomainOpenLogFile(virLogManagerPtr mgr,
     args.driver = (char *)driver;
     memcpy(args.dom.uuid, domuuid, VIR_UUID_BUFLEN);
     args.dom.name = (char *)domname;
+    args.path = (char *)path;
     args.flags = flags;
 
     if (virNetClientProgramCall(mgr->program,
@@ -211,9 +213,7 @@ virLogManagerDomainOpenLogFile(virLogManagerPtr mgr,
 
 int
 virLogManagerDomainGetLogFilePosition(virLogManagerPtr mgr,
-                                      const char *driver,
-                                      const unsigned char *domuuid,
-                                      const char *domname,
+                                      const char *path,
                                       unsigned int flags,
                                       ino_t *inode,
                                       off_t *offset)
@@ -225,9 +225,7 @@ virLogManagerDomainGetLogFilePosition(virLogManagerPtr mgr,
     memset(&args, 0, sizeof(args));
     memset(&ret, 0, sizeof(ret));
 
-    args.driver = (char *)driver;
-    memcpy(args.dom.uuid, domuuid, VIR_UUID_BUFLEN);
-    args.dom.name = (char *)domname;
+    args.path = (char *)path;
     args.flags = flags;
 
     if (virNetClientProgramCall(mgr->program,
@@ -250,9 +248,7 @@ virLogManagerDomainGetLogFilePosition(virLogManagerPtr mgr,
 
 char *
 virLogManagerDomainReadLogFile(virLogManagerPtr mgr,
-                               const char *driver,
-                               const unsigned char *domuuid,
-                               const char *domname,
+                               const char *path,
                                ino_t inode,
                                off_t offset,
                                size_t maxlen,
@@ -267,9 +263,7 @@ virLogManagerDomainReadLogFile(virLogManagerPtr mgr,
     memset(&args, 0, sizeof(args));
     memset(&ret, 0, sizeof(ret));
 
-    args.driver = (char *)driver;
-    memcpy(args.dom.uuid, domuuid, VIR_UUID_BUFLEN);
-    args.dom.name = (char *)domname;
+    args.path = (char *)path;
     args.flags = flags;
     args.pos.inode = inode;
     args.pos.offset = offset;
diff --git a/src/logging/log_manager.h b/src/logging/log_manager.h
index 3dfe516..d3b9d29 100644
--- a/src/logging/log_manager.h
+++ b/src/logging/log_manager.h
@@ -37,22 +37,19 @@ int virLogManagerDomainOpenLogFile(virLogManagerPtr mgr,
                                    const char *driver,
                                    const unsigned char *domuuid,
                                    const char *domname,
+                                   const char *path,
                                    unsigned int flags,
                                    ino_t *inode,
                                    off_t *offset);
 
 int virLogManagerDomainGetLogFilePosition(virLogManagerPtr mgr,
-                                          const char *driver,
-                                          const unsigned char *domuuid,
-                                          const char *domname,
+                                          const char *path,
                                           unsigned int flags,
                                           ino_t *inode,
                                           off_t *offset);
 
 char *virLogManagerDomainReadLogFile(virLogManagerPtr mgr,
-                                     const char *driver,
-                                     const unsigned char *domuuid,
-                                     const char *domname,
+                                     const char *path,
                                      ino_t inode,
                                      off_t offset,
                                      size_t maxlen,
diff --git a/src/logging/log_protocol.x b/src/logging/log_protocol.x
index de57c69..a07334f 100644
--- a/src/logging/log_protocol.x
+++ b/src/logging/log_protocol.x
@@ -35,6 +35,7 @@ typedef struct virLogManagerProtocolLogFilePosition
virLogManagerProtocolLogFile
 struct virLogManagerProtocolDomainOpenLogFileArgs {
     virLogManagerProtocolNonNullString driver;
     virLogManagerProtocolDomain dom;
+    virLogManagerProtocolNonNullString path;
     unsigned int flags;
 };
 
@@ -43,8 +44,7 @@ struct virLogManagerProtocolDomainOpenLogFileRet {
 };
 
 struct virLogManagerProtocolDomainGetLogFilePositionArgs {
-    virLogManagerProtocolNonNullString driver;
-    virLogManagerProtocolDomain dom;
+    virLogManagerProtocolNonNullString path;
     unsigned int flags;
 };
 
@@ -53,8 +53,7 @@ struct virLogManagerProtocolDomainGetLogFilePositionRet {
 };
 
 struct virLogManagerProtocolDomainReadLogFileArgs {
-    virLogManagerProtocolNonNullString driver;
-    virLogManagerProtocolDomain dom;
+    virLogManagerProtocolNonNullString path;
     virLogManagerProtocolLogFilePosition pos;
     unsigned hyper maxlen;
     unsigned int flags;
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 4d6c595..438f7a1 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -85,8 +85,7 @@ struct _qemuDomainLogContext {
     int readfd; /* Only used if manager == NULL */
     off_t pos;
     ino_t inode; /* Only used if manager != NULL */
-    unsigned char uuid[VIR_UUID_BUFLEN]; /* Only used if manager != NULL */
-    char *name; /* Only used if manager != NULL */
+    char *path;
     virLogManagerPtr manager;
 };
 
@@ -2285,7 +2284,6 @@ qemuDomainLogContextPtr qemuDomainLogContextNew(virQEMUDriverPtr
driver,
 {
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
     qemuDomainLogContextPtr ctxt = NULL;
-    char *logfile = NULL;
 
     if (VIR_ALLOC(ctxt) < 0)
         goto error;
@@ -2295,37 +2293,33 @@ qemuDomainLogContextPtr qemuDomainLogContextNew(virQEMUDriverPtr
driver,
     ctxt->readfd = -1;
     virAtomicIntSet(&ctxt->refs, 1);
 
+    if (virAsprintf(&ctxt->path, "%s/%s.log", cfg->logDir,
vm->def->name) < 0)
+        goto error;
+
     if (cfg->stdioLogD) {
         ctxt->manager = virLogManagerNew(virQEMUDriverIsPrivileged(driver));
         if (!ctxt->manager)
             goto error;
 
-        if (VIR_STRDUP(ctxt->name, vm->def->name) < 0)
-            goto error;
-
-        memcpy(ctxt->uuid, vm->def->uuid, VIR_UUID_BUFLEN);
-
         ctxt->writefd = virLogManagerDomainOpenLogFile(ctxt->manager,
                                                        "qemu",
                                                        vm->def->uuid,
                                                        vm->def->name,
+                                                       ctxt->path,
                                                        0,
                                                        &ctxt->inode,
                                                        &ctxt->pos);
         if (ctxt->writefd < 0)
             goto error;
     } else {
-        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) {
+        if ((ctxt->writefd = open(ctxt->path, O_WRONLY | O_CREAT | O_APPEND,
S_IRUSR | S_IWUSR)) < 0) {
             virReportSystemError(errno, _("failed to create logfile %s"),
-                                 logfile);
+                                 ctxt->path);
             goto error;
         }
         if (virSetCloseExec(ctxt->writefd) < 0) {
             virReportSystemError(errno, _("failed to set close-on-exec flag on
%s"),
-                                 logfile);
+                                 ctxt->path);
             goto error;
         }
 
@@ -2336,33 +2330,32 @@ qemuDomainLogContextPtr qemuDomainLogContextNew(virQEMUDriverPtr
driver,
             !virQEMUDriverIsPrivileged(driver) &&
             ftruncate(ctxt->writefd, 0) < 0) {
             virReportSystemError(errno, _("failed to truncate %s"),
-                                 logfile);
+                                 ctxt->path);
             goto error;
         }
 
         if (mode == QEMU_DOMAIN_LOG_CONTEXT_MODE_START) {
-            if ((ctxt->readfd = open(logfile, O_RDONLY, S_IRUSR | S_IWUSR)) < 0) {
+            if ((ctxt->readfd = open(ctxt->path, O_RDONLY, S_IRUSR | S_IWUSR)) <
0) {
                 virReportSystemError(errno, _("failed to open logfile %s"),
-                                     logfile);
+                                     ctxt->path);
                 goto error;
             }
             if (virSetCloseExec(ctxt->readfd) < 0) {
                 virReportSystemError(errno, _("failed to set close-on-exec flag on
%s"),
-                                     logfile);
+                                     ctxt->path);
                 goto error;
             }
         }
 
         if ((ctxt->pos = lseek(ctxt->writefd, 0, SEEK_END)) < 0) {
             virReportSystemError(errno, _("failed to seek in log file %s"),
-                                 logfile);
+                                 ctxt->path);
             goto error;
         }
     }
 
  cleanup:
     virObjectUnref(cfg);
-    VIR_FREE(logfile);
     return ctxt;
 
  error:
@@ -2415,9 +2408,7 @@ ssize_t qemuDomainLogContextRead(qemuDomainLogContextPtr ctxt,
     size_t buflen;
     if (ctxt->manager) {
         buf = virLogManagerDomainReadLogFile(ctxt->manager,
-                                             "qemu",
-                                             ctxt->uuid,
-                                             ctxt->name,
+                                             ctxt->path,
                                              ctxt->inode,
                                              ctxt->pos,
                                              1024 * 128,
@@ -2466,9 +2457,7 @@ void qemuDomainLogContextMarkPosition(qemuDomainLogContextPtr ctxt)
 {
     if (ctxt->manager)
         virLogManagerDomainGetLogFilePosition(ctxt->manager,
-                                              "qemu",
-                                              ctxt->uuid,
-                                              ctxt->name,
+                                              ctxt->path,
                                               0,
                                               &ctxt->inode,
                                               &ctxt->pos);
@@ -2497,7 +2486,7 @@ void qemuDomainLogContextFree(qemuDomainLogContextPtr ctxt)
         return;
 
     virLogManagerFree(ctxt->manager);
-    VIR_FREE(ctxt->name);
+    VIR_FREE(ctxt->path);
     VIR_FORCE_CLOSE(ctxt->writefd);
     VIR_FORCE_CLOSE(ctxt->readfd);
     VIR_FREE(ctxt);
-- 
2.5.0


    

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[libvirt] [PATCH 3/4] logging: change log protocol to be more reusable