posix_spawn style updates

- This adds a wrapper function for the call sequence
of posix_spawn and posix_spawnp.
- Replaces perror() with fuse_log - the latter
can be redirected through the file system log function
and gives better end user friendly output
- other minor changes, like variable renames
- no functional change

diff --git a/lib/mount.c b/lib/mount.c
index 2ffb05c8410af09332a46ce1cb28db0455d0c232..3fbbe72cf7ecd5b50e49f9a3d81ab26f3d11a1f0 100644 (file)
--- a/lib/mount.c
+++ b/lib/mount.c
@@ -117,18 +117,51 @@ static const struct fuse_opt fuse_mount_opts[] = {
        FUSE_OPT_END
 };
 
-void fuse_mount_version(void)
+/*
+ * Running fusermount by calling 'posix_spawn'
+ *
+ * @param out_pid might be NULL
+ */
+static int fusermount_posix_spawn(posix_spawn_file_actions_t *action,
+                                 char const * const argv[], pid_t *out_pid)
 {
-       char const *const argv[] = {FUSERMOUNT_PROG, "--version", NULL};
+       const char *full_path = FUSERMOUNT_DIR "/" FUSERMOUNT_PROG;
        pid_t pid;
-       int status = posix_spawn(&pid, FUSERMOUNT_DIR "/" FUSERMOUNT_PROG, NULL,
-                       NULL, (char * const *) argv, environ)
-               && posix_spawnp(&pid, FUSERMOUNT_PROG, NULL,
-                       NULL, (char * const *) argv, environ);
-       if(status != 0)
-               perror("posix_spawn");
+
+       /* See man 7 environ for the global environ pointer */
+
+       /* first try the install path */
+       int status = posix_spawn(&pid, full_path,  action, NULL,
+                                (char * const *) argv, environ);
+       if (status != 0) {
+               /* if that fails, try a system install */
+               status = posix_spawnp(&pid, FUSERMOUNT_PROG, action, NULL,
+                                     (char * const *) argv, environ);
+       }
+
+       if (status != 0) {
+               fuse_log(FUSE_LOG_ERR,
+                        "On calling fusermount posix_spawn failed: %s\n",
+                        strerror(status));
+               return -status;
+       }
+
+       if (out_pid)
+               *out_pid = pid;
        else
                waitpid(pid, NULL, 0);
+
+       return 0;
+}
+
+void fuse_mount_version(void)
+{
+       char const *const argv[] = {FUSERMOUNT_PROG, "--version", NULL};
+       int status = fusermount_posix_spawn(NULL, argv, NULL);
+
+       if(status != 0)
+               fuse_log(FUSE_LOG_ERR, "Running '%s --version' failed",
+                        FUSERMOUNT_PROG);
 }
 
 struct mount_flags {
@@ -246,7 +279,7 @@ static int receive_fd(int fd)
 
        while(((rv = recvmsg(fd, &msg, 0)) == -1) && errno == EINTR);
        if (rv == -1) {
-               perror("recvmsg");
+               fuse_log(FUSE_LOG_ERR, "recvmsg failed: %s", strerror(errno));
                return -1;
        }
        if(!rv) {
@@ -266,7 +299,6 @@ static int receive_fd(int fd)
 void fuse_kern_unmount(const char *mountpoint, int fd)
 {
        int res;
-       pid_t pid;
 
        if (fd != -1) {
                struct pollfd pfd;
@@ -301,15 +333,12 @@ void fuse_kern_unmount(const char *mountpoint, int fd)
        char const * const argv[] =
                { FUSERMOUNT_PROG, "--unmount", "--quiet", "--lazy",
                                "--", mountpoint, NULL };
-       int status = posix_spawn(
-               &pid, FUSERMOUNT_DIR "/" FUSERMOUNT_PROG, NULL, NULL, (char * const *) argv, environ)
-               && posix_spawnp(
-                       &pid, FUSERMOUNT_PROG, NULL, NULL, (char * const *) argv, environ);
+       int status = fusermount_posix_spawn(NULL, argv, NULL);
        if(status != 0) {
-               perror("posix_spawn");
+               fuse_log(FUSE_LOG_ERR, "Spawaning %s to unumount failed",
+                        FUSERMOUNT_PROG);
                return;
        }
-       waitpid(pid, NULL, 0);
 }
 
 static int setup_auto_unmount(const char *mountpoint, int quiet)
@@ -325,7 +354,8 @@ static int setup_auto_unmount(const char *mountpoint, int quiet)
 
        res = socketpair(PF_UNIX, SOCK_STREAM, 0, fds);
        if(res == -1) {
-               perror("fuse: socketpair() failed");
+               fuse_log(FUSE_LOG_ERR, "Setting up auto-unmountsocketpair() failed",
+                        strerror(errno));
                return -1;
        }
 
@@ -351,16 +381,18 @@ static int setup_auto_unmount(const char *mountpoint, int quiet)
        }
        posix_spawn_file_actions_addclose(&action, fds[1]);
 
-       int status = posix_spawn(&pid, FUSERMOUNT_DIR "/" FUSERMOUNT_PROG, &action,
-                       NULL, (char *const *) argv, environ)
-               && posix_spawnp(&pid, FUSERMOUNT_PROG, &action,
-                       NULL, (char *const *) argv, environ);
+       /*
+        * auto-umount runs in the background - it is not waiting for the
+        * process
+        */
+       int status = fusermount_posix_spawn(&action, argv, &pid);
+
        posix_spawn_file_actions_destroy(&action);
 
        if(status != 0) {
                close(fds[0]);
                close(fds[1]);
-               perror("fuse: posix_spawnp() of fusermount3 failed");
+               fuse_log(FUSE_LOG_ERR, "fuse: Setting up auto-unmount failed");
                return -1;
        }
        // passed to child now, so can close here.
@@ -386,7 +418,8 @@ static int fuse_mount_fusermount(const char *mountpoint, struct mount_opts *mo,
 
        res = socketpair(PF_UNIX, SOCK_STREAM, 0, fds);
        if(res == -1) {
-               perror("fuse: socketpair() failed");
+               fuse_log(FUSE_LOG_ERR, "Running %s: socketpair() failed: %s\n",
+                        FUSERMOUNT_PROG, strerror(errno));
                return -1;
        }
 
@@ -412,23 +445,22 @@ static int fuse_mount_fusermount(const char *mountpoint, struct mount_opts *mo,
        }
        posix_spawn_file_actions_addclose(&action, fds[1]);
 
-       int status = posix_spawn(&pid, FUSERMOUNT_DIR "/" FUSERMOUNT_PROG, &action,
-                       NULL, (char *const *) argv, environ)
-               && posix_spawnp(&pid, FUSERMOUNT_PROG, &action,
-                       NULL, (char *const *) argv, environ);
+       int status = fusermount_posix_spawn(&action, argv, &pid);
+
        posix_spawn_file_actions_destroy(&action);
 
        if(status != 0) {
                close(fds[0]);
                close(fds[1]);
-               perror("fuse: posix_spawnp() of fusermount3 failed");
+               fuse_log(FUSE_LOG_ERR, "posix_spawnp() for %s failed",
+                        FUSERMOUNT_PROG, strerror(errno));
                return -1;
        }
 
        // passed to child now, so can close here.
        close(fds[0]);
 
-       int rv = receive_fd(fds[1]);
+       int fd = receive_fd(fds[1]);
 
        if (!mo->auto_unmount) {
                /* with auto_unmount option fusermount3 will not exit until
@@ -437,10 +469,10 @@ static int fuse_mount_fusermount(const char *mountpoint, struct mount_opts *mo,
                waitpid(pid, NULL, 0); /* bury zombie */
        }
 
-       if (rv >= 0)
-               fcntl(rv, F_SETFD, FD_CLOEXEC);
+       if (fd >= 0)
+               fcntl(fd, F_SETFD, FD_CLOEXEC);
 
-       return rv;
+       return fd;
 }
 
 #ifndef O_CLOEXEC