[libvirt] [PATCHv2 ACKed 02/15] util: eliminate extra args from virExec

Laine Stump laine at laine.org
Tue Feb 12 20:15:36 UTC 2013


All args except "cmd" in the call to virExec are now redundant, since
they can all be found in cmd, so remove the args and reference the
data directly in cmd. One exception to this is that "infd" was being
modified within virExec, and modifying the original in cmd caused make
check failures, so cmd->infd is copied to a local, and the local is
used during virExec().
---
Change from V1: rebased.

 src/util/vircommand.c | 142 +++++++++++++++++---------------------------------
 1 file changed, 49 insertions(+), 93 deletions(-)

diff --git a/src/util/vircommand.c b/src/util/vircommand.c
index 02bf50d..b41c78b 100644
--- a/src/util/vircommand.c
+++ b/src/util/vircommand.c
@@ -378,40 +378,18 @@ prepareStdFd(int fd, int std)
 }
 
 /*
- * @argv argv to exec
- * @envp optional environment to use for exec
- * @keepfd options fd_ret to keep open for child process
- * @retpid optional pointer to store child process pid
- * @infd optional file descriptor to use as child input, otherwise /dev/null
- * @outfd optional pointer to communicate output fd behavior
- *        outfd == NULL : Use /dev/null
- *        *outfd == -1  : Use a new fd
- *        *outfd != -1  : Use *outfd
- * @errfd optional pointer to communcate error fd behavior. See outfd
- * @flags possible combination of the following:
- *        VIR_EXEC_NONE     : Default function behavior
- *        VIR_EXEC_NONBLOCK : Set child process output fd's as non-blocking
- *        VIR_EXEC_DAEMON   : Daemonize the child process
- * @cmd virCommandPtr to pass to virCommandHook
- * @pidfile path to use as pidfile for daemonized process (needs DAEMON flag)
- * @capabilities capabilities to keep
+ * virExec:
+ * @cmd virCommandPtr containing all information about the program to
+ *      exec.
  */
 static int
-virExec(virCommandPtr cmd,
-                const char *const*argv,
-                const char *const*envp,
-                const int *keepfd,
-                int keepfd_size,
-                pid_t *retpid,
-                int infd, int *outfd, int *errfd,
-                unsigned int flags,
-                char *pidfile,
-                unsigned long long capabilities)
+virExec(virCommandPtr cmd)
 {
     pid_t pid;
     int null = -1, i, openmax;
     int pipeout[2] = {-1,-1};
     int pipeerr[2] = {-1,-1};
+    int childin = cmd->infd;
     int childout = -1;
     int childerr = -1;
     int tmpfd;
@@ -419,41 +397,41 @@ virExec(virCommandPtr cmd,
     int forkRet;
     struct sigaction waxon, waxoff;
 
-    if (argv[0][0] != '/') {
-        if (!(binary = virFindFileInPath(argv[0]))) {
+    if (cmd->args[0][0] != '/') {
+        if (!(binary = virFindFileInPath(cmd->args[0]))) {
             virReportSystemError(ENOENT,
                                  _("Cannot find '%s' in path"),
-                                 argv[0]);
+                                 cmd->args[0]);
             return -1;
         }
     } else {
-        binary = argv[0];
+        binary = cmd->args[0];
     }
 
-    if (infd < 0) {
+    if (childin < 0) {
         if (getDevNull(&null) < 0)
             goto cleanup;
-        infd = null;
+        childin = null;
     }
 
-    if (outfd != NULL) {
-        if (*outfd == -1) {
+    if (cmd->outfdptr != NULL) {
+        if (*cmd->outfdptr == -1) {
             if (pipe2(pipeout, O_CLOEXEC) < 0) {
                 virReportSystemError(errno,
                                      "%s", _("cannot create pipe"));
                 goto cleanup;
             }
 
-            if ((flags & VIR_EXEC_NONBLOCK) &&
+            if ((cmd->flags & VIR_EXEC_NONBLOCK) &&
                 virSetNonBlock(pipeout[0]) == -1) {
-                virReportSystemError(errno,
-                                     "%s", _("Failed to set non-blocking file descriptor flag"));
+                virReportSystemError(errno, "%s",
+                                     _("Failed to set non-blocking file descriptor flag"));
                 goto cleanup;
             }
 
             childout = pipeout[1];
         } else {
-            childout = *outfd;
+            childout = *cmd->outfdptr;
         }
     } else {
         if (getDevNull(&null) < 0)
@@ -461,26 +439,26 @@ virExec(virCommandPtr cmd,
         childout = null;
     }
 
-    if (errfd != NULL) {
-        if (errfd == outfd) {
+    if (cmd->errfdptr != NULL) {
+        if (cmd->errfdptr == cmd->outfdptr) {
             childerr = childout;
-        } else if (*errfd == -1) {
+        } else if (*cmd->errfdptr == -1) {
             if (pipe2(pipeerr, O_CLOEXEC) < 0) {
                 virReportSystemError(errno,
                                      "%s", _("Failed to create pipe"));
                 goto cleanup;
             }
 
-            if ((flags & VIR_EXEC_NONBLOCK) &&
+            if ((cmd->flags & VIR_EXEC_NONBLOCK) &&
                 virSetNonBlock(pipeerr[0]) == -1) {
-                virReportSystemError(errno,
-                                     "%s", _("Failed to set non-blocking file descriptor flag"));
+                virReportSystemError(errno, "%s",
+                                     _("Failed to set non-blocking file descriptor flag"));
                 goto cleanup;
             }
 
             childerr = pipeerr[1];
         } else {
-            childerr = *errfd;
+            childerr = *cmd->errfdptr;
         }
     } else {
         if (getDevNull(&null) < 0)
@@ -500,18 +478,18 @@ virExec(virCommandPtr cmd,
         }
 
         VIR_FORCE_CLOSE(null);
-        if (outfd && *outfd == -1) {
+        if (cmd->outfdptr && *cmd->outfdptr == -1) {
             VIR_FORCE_CLOSE(pipeout[1]);
-            *outfd = pipeout[0];
+            *cmd->outfdptr = pipeout[0];
         }
-        if (errfd && *errfd == -1) {
+        if (cmd->errfdptr && *cmd->errfdptr == -1) {
             VIR_FORCE_CLOSE(pipeerr[1]);
-            *errfd = pipeerr[0];
+            *cmd->errfdptr = pipeerr[0];
         }
 
-        *retpid = pid;
+        cmd->pid = pid;
 
-        if (binary != argv[0])
+        if (binary != cmd->args[0])
             VIR_FREE(binary);
 
         return 0;
@@ -528,9 +506,10 @@ virExec(virCommandPtr cmd,
 
     openmax = sysconf(_SC_OPEN_MAX);
     for (i = 3; i < openmax; i++) {
-        if (i == infd || i == childout || i == childerr)
+        if (i == childin || i == childout || i == childerr)
             continue;
-        if (!keepfd || !virCommandFDIsSet(i, keepfd, keepfd_size)) {
+        if (!cmd->preserve ||
+            !virCommandFDIsSet(i, cmd->preserve, cmd->preserve_size)) {
             tmpfd = i;
             VIR_MASS_CLOSE(tmpfd);
         } else if (virSetInherit(i, true) < 0) {
@@ -539,7 +518,7 @@ virExec(virCommandPtr cmd,
         }
     }
 
-    if (prepareStdFd(infd, STDIN_FILENO) < 0) {
+    if (prepareStdFd(childin, STDIN_FILENO) < 0) {
         virReportSystemError(errno,
                              "%s", _("failed to setup stdin file handle"));
         goto fork_error;
@@ -555,9 +534,9 @@ virExec(virCommandPtr cmd,
         goto fork_error;
     }
 
-    if (infd != STDIN_FILENO && infd != null && infd != childerr &&
-        infd != childout)
-        VIR_FORCE_CLOSE(infd);
+    if (childin != STDIN_FILENO && childin != null &&
+        childin != childerr && childin != childout)
+        VIR_FORCE_CLOSE(childin);
     if (childout > STDERR_FILENO && childout != null && childout != childerr)
         VIR_FORCE_CLOSE(childout);
     if (childerr > STDERR_FILENO && childerr != null)
@@ -569,7 +548,7 @@ virExec(virCommandPtr cmd,
 
     /* Daemonize as late as possible, so the parent process can detect
      * the above errors with wait* */
-    if (flags & VIR_EXEC_DAEMON) {
+    if (cmd->flags & VIR_EXEC_DAEMON) {
         if (setsid() < 0) {
             virReportSystemError(errno,
                                  "%s", _("cannot become session leader"));
@@ -590,13 +569,13 @@ virExec(virCommandPtr cmd,
         }
 
         if (pid > 0) {
-            if (pidfile && (virPidFileWritePath(pidfile,pid) < 0)) {
+            if (cmd->pidfile && (virPidFileWritePath(cmd->pidfile, pid) < 0)) {
                 kill(pid, SIGTERM);
                 usleep(500*1000);
                 kill(pid, SIGTERM);
                 virReportSystemError(errno,
                                      _("could not write pidfile %s for %d"),
-                                     pidfile, pid);
+                                     cmd->pidfile, pid);
                 goto fork_error;
             }
             _exit(0);
@@ -631,21 +610,21 @@ virExec(virCommandPtr cmd,
 
     /* The steps above may need todo something privileged, so
      * we delay clearing capabilities until the last minute */
-    if (capabilities || (flags & VIR_EXEC_CLEAR_CAPS))
-        if (virSetCapabilities(capabilities) < 0)
+    if (cmd->capabilities || (cmd->flags & VIR_EXEC_CLEAR_CAPS))
+        if (virSetCapabilities(cmd->capabilities) < 0)
             goto fork_error;
 
     /* Close logging again to ensure no FDs leak to child */
     virLogReset();
 
-    if (envp)
-        execve(binary, (char **) argv, (char**)envp);
+    if (cmd->env)
+        execve(binary, cmd->args, cmd->env);
     else
-        execv(binary, (char **) argv);
+        execv(binary, cmd->args);
 
     virReportSystemError(errno,
                          _("cannot execute binary %s"),
-                         argv[0]);
+                         cmd->args[0]);
 
  fork_error:
     virDispatchError(NULL);
@@ -655,7 +634,7 @@ virExec(virCommandPtr cmd,
     /* This is cleanup of parent process only - child
        should never jump here on error */
 
-    if (binary != argv[0])
+    if (binary != cmd->args[0])
         VIR_FREE(binary);
 
     /* NB we don't virReportError() on any failures here
@@ -710,18 +689,7 @@ virRun(const char *const *argv ATTRIBUTE_UNUSED,
 }
 
 static int
-virExec(virCommandPtr cmd ATTRIBUTE_UNUSED,
-                const char *const*argv ATTRIBUTE_UNUSED,
-                const char *const*envp ATTRIBUTE_UNUSED,
-                const int *keepfd ATTRIBUTE_UNUSED,
-                int keepfd_size ATTRIBUTE_UNUSED,
-                pid_t *retpid ATTRIBUTE_UNUSED,
-                int infd ATTRIBUTE_UNUSED,
-                int *outfd ATTRIBUTE_UNUSED,
-                int *errfd ATTRIBUTE_UNUSED,
-                int flags_unused ATTRIBUTE_UNUSED,
-                char *pidfile ATTRIBUTE_UNUSED,
-                unsigned long long capabilities ATTRIBUTE_UNUSED)
+virExec(virCommandPtr cmd ATTRIBUTE_UNUSED)
 {
     /* XXX: Some day we can implement pieces of virCommand/virExec on
      * top of _spawn() or CreateProcess(), but we can't implement
@@ -2397,19 +2365,7 @@ virCommandRunAsync(virCommandPtr cmd, pid_t *pid)
     VIR_DEBUG("About to run %s", str ? str : cmd->args[0]);
     VIR_FREE(str);
 
-    ret = virExec(cmd,
-                          (const char *const *)cmd->args,
-                          (const char *const *)cmd->env,
-                          cmd->preserve,
-                          cmd->preserve_size,
-                          &cmd->pid,
-                          cmd->infd,
-                          cmd->outfdptr,
-                          cmd->errfdptr,
-                          cmd->flags,
-                          cmd->pidfile,
-                          cmd->capabilities);
-
+    ret = virExec(cmd);
     VIR_DEBUG("Command result %d, with PID %d",
               ret, (int)cmd->pid);
 
-- 
1.8.1




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