Use vfork instead of fork, some more cleanup from Vladimir N. Oleynik

1 files changed, 31 insertions, 31 deletions

diff --git a/archival/tar.c b/archival/tar.c
index bafb7033c..379220291 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -138,24 +138,20 @@ enum TarFileType {
 typedef enum TarFileType TarFileType;
 
 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
-static inline void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr, dev_t dev,
-                                                                   ino_t ino, short linkCount,
-                                                                   const char *name)
+static inline void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,
+                                        struct stat *statbuf,
+                                        const char *name)
 {
         /* Note: hlInfoHeadPtr can never be NULL! */
         HardLinkInfo *hlInfo;
 
-        hlInfo =
-                (HardLinkInfo *) xmalloc(sizeof(HardLinkInfo) + strlen(name) + 1);
-        if (hlInfo) {
-                hlInfo->next = *hlInfoHeadPtr;
-                *hlInfoHeadPtr = hlInfo;
-                hlInfo->dev = dev;
-                hlInfo->ino = ino;
-                hlInfo->linkCount = linkCount;
-                strcpy(hlInfo->name, name);
-        }
-        return;
+        hlInfo = (HardLinkInfo *) xmalloc(sizeof(HardLinkInfo) + strlen(name));
+        hlInfo->next = *hlInfoHeadPtr;
+        *hlInfoHeadPtr = hlInfo;
+        hlInfo->dev = statbuf->st_dev;
+        hlInfo->ino = statbuf->st_ino;
+        hlInfo->linkCount = statbuf->st_nlink;
+        strcpy(hlInfo->name, name);
 }
 
 static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
@@ -176,11 +172,10 @@ static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
 }
 
 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
-static inline HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, dev_t dev,
-                                                                                         ino_t ino)
+static inline HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbuf)
 {
         while (hlInfo) {
-                if ((ino == hlInfo->ino) && (dev == hlInfo->dev))
+                if ((statbuf->st_ino == hlInfo->ino) && (statbuf->st_dev == hlInfo->dev))
                         break;
                 hlInfo = hlInfo->next;
         }
@@ -366,11 +361,9 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf,
          */
         tbInfo->hlInfo = NULL;
         if (statbuf->st_nlink > 1) {
-                tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf->st_dev,
-                                                                                  statbuf->st_ino);
+                tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf);
                 if (tbInfo->hlInfo == NULL)
-                        addHardLinkInfo(&tbInfo->hlInfoHead, statbuf->st_dev,
-                                                        statbuf->st_ino, statbuf->st_nlink, fileName);
+                        addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, fileName);
         }
 
         /* It is against the rules to archive a socket */
@@ -460,6 +453,7 @@ static inline int writeTarFile(const char *tarName, const int verboseFlag,
         int gzipDataPipe[2] = { -1, -1 };
         int gzipStatusPipe[2] = { -1, -1 };
         pid_t gzipPid = 0;
+        volatile int vfork_exec_errno = 0;
 #endif
 
         int errorFlag = FALSE;
@@ -495,13 +489,19 @@ static inline int writeTarFile(const char *tarName, const int verboseFlag,
 
 #ifdef CONFIG_FEATURE_TAR_GZIP
         if (gzip) {
-                if (socketpair(AF_UNIX, SOCK_STREAM, 0, gzipDataPipe) < 0
-                        || pipe(gzipStatusPipe) < 0)
+                if (pipe(gzipDataPipe) < 0 || pipe(gzipStatusPipe) < 0) {
                         perror_msg_and_die("Failed to create gzip pipe");
+                }
 
                 signal(SIGPIPE, SIG_IGN);       /* we only want EPIPE on errors */
 
-                gzipPid = fork();
+# if __GNUC__
+                        /* Avoid vfork clobbering */
+                        (void) &include;
+                        (void) &errorFlag;
+# endif
+ 
+                gzipPid = vfork();
 
                 if (gzipPid == 0) {
                         dup2(gzipDataPipe[0], 0);
@@ -514,10 +514,9 @@ static inline int writeTarFile(const char *tarName, const int verboseFlag,
                         fcntl(gzipStatusPipe[1], F_SETFD, FD_CLOEXEC);  /* close on exec shows sucess */
 
                         execl("/bin/gzip", "gzip", "-f", 0);
+                        vfork_exec_errno = errno;
 
-                        write(gzipStatusPipe[1], "", 1);
                         close(gzipStatusPipe[1]);
-
                         exit(-1);
                 } else if (gzipPid > 0) {
                         close(gzipDataPipe[0]);
@@ -528,9 +527,10 @@ static inline int writeTarFile(const char *tarName, const int verboseFlag,
 
                                 int n = read(gzipStatusPipe[0], &buf, 1);
 
-                                if (n == 1)
-                                        error_msg_and_die("Could not exec gzip process");       /* socket was not closed => error */
-                                else if ((n < 0) && (errno == EAGAIN || errno == EINTR))
+                                if (n == 0 && vfork_exec_errno != 0) {
+                                        errno = vfork_exec_errno;
+                                        perror_msg_and_die("Could not exec gzip process");
+                                } else if ((n < 0) && (errno == EAGAIN || errno == EINTR))
                                         continue;       /* try it again */
                                 break;
                         }
@@ -538,7 +538,7 @@ static inline int writeTarFile(const char *tarName, const int verboseFlag,
 
                         tbInfo.tarFd = gzipDataPipe[1];
                 } else {
-                        perror_msg_and_die("Failed to fork gzip process");
+                        perror_msg_and_die("Failed to vfork gzip process");
                 }
         }
 #endif
@@ -603,7 +603,7 @@ int tar_main(int argc, char **argv)
         archive_handle_t *tar_handle;
         int opt;
         char *base_dir = NULL;
-        char *tar_filename = "-";
+        const char *tar_filename = "-";
 
 #ifdef CONFIG_FEATURE_TAR_CREATE
         unsigned char tar_create = FALSE;